text
null | inputs
dict | prediction
null | prediction_agent
null | annotation
list | annotation_agent
null | multi_label
bool 1
class | explanation
null | id
stringlengths 1
5
| metadata
null | status
stringclasses 2
values | event_timestamp
null | metrics
null |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
null |
{
"abstract": " We formulate and study a general family of (continuous-time) stochastic\ndynamics for accelerated first-order minimization of smooth convex functions.\nBuilding on an averaging formulation of accelerated mirror descent, we propose\na stochastic variant in which the gradient is contaminated by noise, and study\nthe resulting stochastic differential equation. We prove a bound on the rate of\nchange of an energy function associated with the problem, then use it to derive\nestimates of convergence rates of the function values, (a.s. and in\nexpectation) both for persistent and asymptotically vanishing noise. We discuss\nthe interaction between the parameters of the dynamics (learning rate and\naveraging weights) and the covariation of the noise process, and show, in\nparticular, how the asymptotic rate of covariation affects the choice of\nparameters and, ultimately, the convergence rate.\n",
"title": "Acceleration and Averaging in Stochastic Mirror Descent Dynamics"
}
| null | null | null | null | true | null |
16601
| null |
Default
| null | null |
null |
{
"abstract": " In Kinetic Inductance Detectors (KIDs) and other similar applications of\nsuperconducting microresonators, both the large and small-signal behaviour of\nthe device may be affected by electrothermal feedback. Microwave power applied\nto read out the device is absorbed by and heats the superconductor\nquasiparticles, changing the superconductor conductivity and hence the readout\npower absorbed in a positive or negative feedback loop. In this work, we\nexplore numerically the implications of an extensible theoretical model of a\ngeneric superconducting microresonator device for a typical KID, incorporating\nrecent work on the power flow between superconductor quasiparticles and\nphonons. This model calculates the large-signal (changes in operating point)\nand small-signal behaviour of a device, allowing us to determine the effect of\nelectrothermal feedback on device responsivity and noise characteristics under\nvarious operating conditions. We also investigate how thermally isolating the\ndevice from the bath, for example by designing the device on a membrane only\nconnected to the bulk substrate by thin legs, affects device performance. We\nfind that at a typical device operating point, positive electrothermal feedback\nreduces the effective thermal conductance from the superconductor\nquasiparticles to the bath, and so increases responsivity to signal\n(pair-breaking) power, increases noise from temperature fluctuations, and\ndecreases the Noise Equivalent Power (NEP). Similarly, increasing the thermal\nisolation of the device while keeping the quasiparticle temperature constant\ndecreases the NEP, but also decreases the device response bandwidth.\n",
"title": "Electrothermal Feedback in Kinetic Inductance Detectors"
}
| null | null | null | null | true | null |
16602
| null |
Default
| null | null |
null |
{
"abstract": " Smoothing is one technique to overcome data sparsity in statistical language\nmodel. Although in its mathematical definition there is no explicit dependency\nupon specific natural language, different natures of natural languages result\nin different effects of smoothing techniques. This is true for Russian language\nas shown by Whittaker (1998). In this paper, We compared Modified Kneser-Ney\nand Witten-Bell smoothing techniques in statistical language model of Bahasa\nIndonesia. We used train sets of totally 22M words that we extracted from\nIndonesian version of Wikipedia. As far as we know, this is the largest train\nset used to build statistical language model for Bahasa Indonesia. The\nexperiments with 3-gram, 5-gram, and 7-gram showed that Modified Kneser-Ney\nconsistently outperforms Witten-Bell smoothing technique in term of perplexity\nvalues. It is interesting to note that our experiments showed 5-gram model for\nModified Kneser-Ney smoothing technique outperforms that of 7-gram. Meanwhile,\nWitten-Bell smoothing is consistently improving over the increase of n-gram\norder.\n",
"title": "Comparison of Modified Kneser-Ney and Witten-Bell Smoothing Techniques in Statistical Language Model of Bahasa Indonesia"
}
| null | null | null | null | true | null |
16603
| null |
Default
| null | null |
null |
{
"abstract": " Structural discrimination appears to be a persistent phenomenon in social\nsystems. We here outline the hypothesis that it can result from the\nevolutionary dynamics of the social system itself. We study the evolutionary\ndynamics of agents with neutral badges in a simple social game and find that\nthe badges are readily discriminated by the system although not being tied to\nthe payoff matrix of the game. The sole property of being distinguishable leads\nto the subsequent discrimination, therefore providing a model for the emergence\nand freezing of social prejudice.\n",
"title": "Social evolution of structural discrimination"
}
| null | null | null | null | true | null |
16604
| null |
Default
| null | null |
null |
{
"abstract": " Robots and control systems rely upon precise timing of sensors and actuators\nin order to operate intelligently. We present a functioning hexapod robot that\nwalks with a dual tripod gait; each tripod is actuated using its own local\ncontroller running on a separate wireless node. We compare and report the\nresults of operating the robot using two different decentralized control\nschemes. With the first scheme, each controller relies on its own local clock\nto generate control signals for the tripod it controls. With the second scheme,\neach controller relies on a variable that is local to itself but that is\nnecessarily the same across controllers as a by-product of their host nodes\nbeing part of a time synchronized IEEE802.15.4e network. The gait\nsynchronization error (time difference between what both controllers believe is\nthe start of the gait period) grows linearly when the controllers use their\nlocal clocks, but remains bounded to within 112 microseconds when the\ncontrollers use their nodes' time synchronized local variable.\n",
"title": "Decentralized Control of a Hexapod Robot Using a Wireless Time Synchronized Network"
}
| null | null | null | null | true | null |
16605
| null |
Default
| null | null |
null |
{
"abstract": " Magnetic domain wall (DW) motion induced by a localized Gaussian temperature\nprofile is studied in a Permalloy nanostrip within the framework of the\nstochastic Landau-Lifshitz-Bloch equation. The different contributions to\nthermally induced DW motion, entropic torque and magnonic spin transfer torque,\nare isolated and compared. The analysis of magnonic spin transfer torque\nincludes a description of thermally excited magnons in the sample. A third\ndriving force due to a thermally induced dipolar field is found and described.\nFinally, thermally induced DW motion is studied under realistic conditions by\ntaking into account the edge roughness. The results give quantitative insights\ninto the different mechanisms responsible for domain wall motion in temperature\ngradients and allow for comparison with experimental results.\n",
"title": "Domain wall motion by localized temperature gradients"
}
| null | null | null | null | true | null |
16606
| null |
Default
| null | null |
null |
{
"abstract": " This paper presents an algorithm that enhances undesirably illuminated images\nby generating and fusing multi-level illuminations from a single image.The\ninput image is first decomposed into illumination and reflectance components by\nusing an edge-preserving smoothing filter. Then the reflectance component is\nscaled up to improve the image details in bright areas. The illumination\ncomponent is scaled up and down to generate several illumination images that\ncorrespond to certain camera exposure values different from the original. The\nvirtual multi-exposure illuminations are blended into an enhanced illumination,\nwhere we also propose a method to generate appropriate weight maps for the tone\nfusion. Finally, an enhanced image is obtained by multiplying the equalized\nillumination and enhanced reflectance. Experiments show that the proposed\nalgorithm produces visually pleasing output and also yields comparable\nobjective results to the conventional enhancement methods, while requiring\nmodest computational loads.\n",
"title": "Generation of High Dynamic Range Illumination from a Single Image for the Enhancement of Undesirably Illuminated Images"
}
| null | null | null | null | true | null |
16607
| null |
Default
| null | null |
null |
{
"abstract": " In this paper we introduce, the FlashText algorithm for replacing keywords or\nfinding keywords in a given text. FlashText can search or replace keywords in\none pass over a document. The time complexity of this algorithm is not\ndependent on the number of terms being searched or replaced. For a document of\nsize N (characters) and a dictionary of M keywords, the time complexity will be\nO(N). This algorithm is much faster than Regex, because regex time complexity\nis O(MxN). It is also different from Aho Corasick Algorithm, as it doesn't\nmatch substrings. FlashText is designed to only match complete words (words\nwith boundary characters on both sides). For an input dictionary of {Apple},\nthis algorithm won't match it to 'I like Pineapple'. This algorithm is also\ndesigned to go for the longest match first. For an input dictionary {Machine,\nLearning, Machine learning} on a string 'I like Machine learning', it will only\nconsider the longest match, which is Machine Learning. We have made python\nimplementation of this algorithm available as open-source on GitHub, released\nunder the permissive MIT License.\n",
"title": "Replace or Retrieve Keywords In Documents at Scale"
}
| null | null | null | null | true | null |
16608
| null |
Default
| null | null |
null |
{
"abstract": " Logistics network is expected that opened facilities work continuously for a\nlong time horizon without any failure, but in real world problems, facilities\nmay face disruptions. This paper studies a reliable joint inventory location\nproblem to optimize the cost of facility locations, customers assignment, and\ninventory management decisions when facilities face failure risks and do not\nwork. In our model we assume when a facility is out of work, its customers may\nbe reassigned to other operational facilities otherwise they must endure high\npenalty costs associated with losing service. For defining the model closer to\nreal world problems, the model is proposed based on pmedian problem and the\nfacilities are considered to have limited capacities. We define a new binary\nvariable for showing that customers are not assigned to any facilities. Our\nproblem involves a biobjective model, the first one minimizes the sum of\nfacility construction costs and expected inventory holding costs, the second\none function that mentions for the first one is minimized maximum expected\ncustomer costs under normal and failure scenarios. For solving this model we\nuse NSGAII and MOSS algorithms have been applied to find the Pareto archive\nsolution. Also, Response Surface Methodology (RSM) is applied for optimizing\nthe NSGAII Algorithm Parameters. We compare the performance of two algorithms\nwith three metrics and the results show NSGAII is more suitable for our model.\n",
"title": "A Multi Objective Reliable Location-Inventory Capacitated Disruption Facility Problem with Penalty Cost Solve with Efficient Meta Historic Algorithms"
}
| null | null | null | null | true | null |
16609
| null |
Default
| null | null |
null |
{
"abstract": " We carried out 2.5-dimensional resistive MHD simulations to study the\nformation mechanism of molecular loops observed by Fukui et al. (2006) at\nGalactic central region. Since it is hard to form molecular loops by uplifting\ndense molecular gas, we study the formation mechanism of molecular gas in\nrising magnetic arcades. This model is based on the in-situ formation model of\nsolar prominences, in which prominences are formed by cooling instability in\nhelical magnetic flux ropes formed by imposing converging and shearing motion\nat footpoints of the magnetic arch anchored to the solar surface. We extended\nthis model to Galactic center scale (a few hundreds pc). Numerical results\nindicate that magnetic reconnection taking place in the current sheet formed\ninside the rising magnetic arcade creates dense blobs confined by the rising\nhelical magnetic flux ropes. Thermal instability taking place in the flux ropes\nforms dense molecular filaments floating at high Galactic latitude. The mass of\nthe filament increases with time, and can exceed 10^5 solar mass.\n",
"title": "Formation of Galactic Prominence in Galactic Central Region"
}
| null | null | null | null | true | null |
16610
| null |
Default
| null | null |
null |
{
"abstract": " Standard probabilistic linear discriminant analysis (PLDA) for speaker\nrecognition assumes that the sample's features (usually, i-vectors) are given\nby a sum of three terms: a term that depends on the speaker identity, a term\nthat models the within-speaker variability and is assumed independent across\nsamples, and a final term that models any remaining variability and is also\nindependent across samples. In this work, we propose a generalization of this\nmodel where the within-speaker variability is not necessarily assumed\nindependent across samples but dependent on another discrete variable. This\nvariable, which we call the channel variable as in the standard PLDA approach,\ncould be, for example, a discrete category for the channel characteristics, the\nlanguage spoken by the speaker, the type of speech in the sample\n(conversational, monologue, read), etc. The value of this variable is assumed\nto be known during training but not during testing. Scoring is performed, as in\nstandard PLDA, by computing a likelihood ratio between the null hypothesis that\nthe two sides of a trial belong to the same speaker versus the alternative\nhypothesis that the two sides belong to different speakers. The two likelihoods\nare computed by marginalizing over two hypothesis about the channels in both\nsides of a trial: that they are the same and that they are different. This way,\nwe expect that the new model will be better at coping with same-channel versus\ndifferent-channel trials than standard PLDA, since knowledge about the channel\n(or language, or speech style) is used during training and implicitly\nconsidered during scoring.\n",
"title": "Joint Probabilistic Linear Discriminant Analysis"
}
| null | null | null | null | true | null |
16611
| null |
Default
| null | null |
null |
{
"abstract": " Deep learning on graph structures has shown exciting results in various\napplications. However, few attentions have been paid to the robustness of such\nmodels, in contrast to numerous research work for image or text adversarial\nattack and defense. In this paper, we focus on the adversarial attacks that\nfool the model by modifying the combinatorial structure of data. We first\npropose a reinforcement learning based attack method that learns the\ngeneralizable attack policy, while only requiring prediction labels from the\ntarget classifier. Also, variants of genetic algorithms and gradient methods\nare presented in the scenario where prediction confidence or gradients are\navailable. We use both synthetic and real-world data to show that, a family of\nGraph Neural Network models are vulnerable to these attacks, in both\ngraph-level and node-level classification tasks. We also show such attacks can\nbe used to diagnose the learned classifiers.\n",
"title": "Adversarial Attack on Graph Structured Data"
}
| null | null |
[
"Computer Science",
"Statistics"
] | null | true | null |
16612
| null |
Validated
| null | null |
null |
{
"abstract": " Kinetic equations play a major rule in modeling large systems of interacting\nparticles. Recently the legacy of classical kinetic theory found novel\napplications in socio-economic and life sciences, where processes characterized\nby large groups of agents exhibit spontaneous emergence of social structures.\nWell-known examples are the formation of clusters in opinion dynamics, the\nappearance of inequalities in wealth distributions, flocking and milling\nbehaviors in swarming models, synchronization phenomena in biological systems\nand lane formation in pedestrian traffic. The construction of kinetic models\ndescribing the above processes, however, has to face the difficulty of the lack\nof fundamental principles since physical forces are replaced by empirical\nsocial forces. These empirical forces are typically constructed with the aim to\nreproduce qualitatively the observed system behaviors, like the emergence of\nsocial structures, and are at best known in terms of statistical information of\nthe modeling parameters. For this reason the presence of random inputs\ncharacterizing the parameters uncertainty should be considered as an essential\nfeature in the modeling process. In this survey we introduce several examples\nof such kinetic models, that are mathematically described by nonlinear Vlasov\nand Fokker--Planck equations, and present different numerical approaches for\nuncertainty quantification which preserve the main features of the kinetic\nsolution.\n",
"title": "Uncertainty quantification for kinetic models in socio-economic and life sciences"
}
| null | null | null | null | true | null |
16613
| null |
Default
| null | null |
null |
{
"abstract": " The meteoric rise of deep learning models in computer vision research, having\nachieved human-level accuracy in image recognition tasks is firm evidence of\nthe impact of representation learning of deep neural networks. In the chemistry\ndomain, recent advances have also led to the development of similar CNN models,\nsuch as Chemception, that is trained to predict chemical properties using\nimages of molecular drawings. In this work, we investigate the effects of\nsystematically removing and adding localized domain-specific information to the\nimage channels of the training data. By augmenting images with only 3\nadditional basic information, and without introducing any architectural\nchanges, we demonstrate that an augmented Chemception (AugChemception)\noutperforms the original model in the prediction of toxicity, activity, and\nsolvation free energy. Then, by altering the information content in the images,\nand examining the resulting model's performance, we also identify two distinct\nlearning patterns in predicting toxicity/activity as compared to solvation free\nenergy. These patterns suggest that Chemception is learning about its tasks in\nthe manner that is consistent with established knowledge. Thus, our work\ndemonstrates that advanced chemical knowledge is not a pre-requisite for deep\nlearning models to accurately predict complex chemical properties.\n",
"title": "How Much Chemistry Does a Deep Neural Network Need to Know to Make Accurate Predictions?"
}
| null | null | null | null | true | null |
16614
| null |
Default
| null | null |
null |
{
"abstract": " Purpose: To develop generic optimization strategies for image reconstruction\nusing graphical processing units (GPUs) in magnetic resonance imaging (MRI) and\nto exemplarily report about our experience with a highly accelerated\nimplementation of the non-linear inversion algorithm (NLINV) for dynamic MRI\nwith high frame rates. Methods: The NLINV algorithm is optimized and ported to\nrun on an a multi-GPU single-node server. The algorithm is mapped to multiple\nGPUs by decomposing the data domain along the channel dimension. Furthermore,\nthe algorithm is decomposed along the temporal domain by relaxing a temporal\nregularization constraint, allowing the algorithm to work on multiple frames in\nparallel. Finally, an autotuning method is presented that is capable of\ncombining different decomposition variants to achieve optimal algorithm\nperformance in different imaging scenarios. Results: The algorithm is\nsuccessfully ported to a multi-GPU system and allows online image\nreconstruction with high frame rates. Real-time reconstruction with low latency\nand frame rates up to 30 frames per second is demonstrated. Conclusion: Novel\nparallel decomposition methods are presented which are applicable to many\niterative algorithms for dynamic MRI. Using these methods to parallelize the\nNLINV algorithm on multiple GPUs it is possible to achieve online image\nreconstruction with high frame rates.\n",
"title": "Accelerated Computing in Magnetic Resonance Imaging -- Real-Time Imaging Using Non-Linear Inverse Reconstruction"
}
| null | null | null | null | true | null |
16615
| null |
Default
| null | null |
null |
{
"abstract": " In this paper, we will investigate the contribution of color names for\nsalient object detection. Each input image is first converted to the color name\nspace, which is consisted of 11 probabilistic channels. By exploring the\ntopological structure relationship between the figure and the ground, we obtain\na saliency map through a linear combination of a set of sequential attention\nmaps. To overcome the limitation of only exploiting the surroundedness cue, two\nglobal cues with respect to color names are invoked for guiding the computation\nof another weighted saliency map. Finally, we integrate the two saliency maps\ninto a unified framework to infer the saliency result. In addition, an improved\npost-processing procedure is introduced to effectively suppress the background\nwhile uniformly highlight the salient objects. Experimental results show that\nthe proposed model produces more accurate saliency maps and performs well\nagainst 23 saliency models in terms of three evaluation metrics on three public\ndatasets.\n",
"title": "Exploiting Color Name Space for Salient Object Detection"
}
| null | null | null | null | true | null |
16616
| null |
Default
| null | null |
null |
{
"abstract": " Recent theoretical predictions of \"unprecedented proximity\" of the electronic\nground state of iridium fluorides to the SU(2) symmetric $j_{\\mathrm{eff}}=1/2$\nlimit, relevant for superconductivity in iridates, motivated us to investigate\ntheir crystal and electronic structure. To this aim, we performed\nhigh-resolution x-ray powder diffraction, Ir L$_3$-edge resonant inelastic\nx-ray scattering, and quantum chemical calculations on Rb$_2$[IrF$_6$] and\nother iridium fluorides. Our results are consistent with the Mott insulating\nscenario predicted by Birol and Haule [Phys. Rev. Lett. 114, 096403 (2015)],\nbut we observe a sizable deviation of the $j_{\\mathrm{eff}}=1/2$ state from the\nSU(2) symmetric limit. Interactions beyond the first coordination shell of\niridium are negligible, hence the iridium fluorides do not show any magnetic\nordering down to at least 20 K. A larger spin-orbit coupling in iridium\nfluorides compared to oxides is ascribed to a reduction of the degree of\ncovalency, with consequences on the possibility to realize spin-orbit-induced\nstrongly correlated physics in iridium fluorides.\n",
"title": "Possibility to realize spin-orbit-induced correlated physics in iridium fluorides"
}
| null | null | null | null | true | null |
16617
| null |
Default
| null | null |
null |
{
"abstract": " The unsteady characteristics of the flow over thick flatback airfoils have\nbeen investigated by means of CFD calculations. Sandia airfoils which have 35%\nmaximum thickness with three different trailing edge thicknesses were selected.\nThe calculations provided good results compared with available experimental\ndata with regard to the lift curve and the impact of trailing edge thickness.\nUnsteady CFD simulations revealed that the Strouhal number is found to be\nindependent of the lift coefficient before stall and increases with the\ntrailing edge. The present work shows the dependency of the Strouhal number and\nthe wake development on the trailing edge thickness. A recommendation of the\nStrouhal number definition is given for flatback airfoils by considering the\ntrailing edge separation at low angle of attack. The detailed unsteady\ncharacteristics of thick flatback airfoils are discussed more in the present\npaper.\n",
"title": "Numerical Investigation of Unsteady Aerodynamic Effects on Thick Flatback Airfoils"
}
| null | null | null | null | true | null |
16618
| null |
Default
| null | null |
null |
{
"abstract": " In this research was implemented the use of an Arduino UNO R3 microcontroller\nto control the movements of a prototype robotic functional developed to perform\nrehabilitation exercises in the wrist joint; This device can be used to assist\nthe physiatrist to rehabilitate the tendinitis, synovitis, rheumatoid arthritis\nand for pre-operative and post-operative therapy in this joint. During the\ndesign stage of the functional prototype, the methodology of the industrial\ndesign process was used from a concurrent engineering approach, through which\nanthropometric studies could be performed related to the dimensions and angles\nof movement of the wrist joint in the population Venezuelan from the\ninformation collected, the design proposal was elaborated, and the use of CAD\nprograms defined the different forms, geometries and materials of the\ncomponents of the rehabilitation device, which were later analyzed using the\nfinite element method for the determination The tensional state of efforts and\nsafety factors through the use of CAE programs. In addition, a software was\ndeveloped for the acquisition, registration, reproduction and execution of the\ndifferent movements produced during the rehabilitation therapy. Through the\nresearch developed, a device was designed that will help the rehabilitation of\nthe wrist joint allowing the combination of dorsal-palmar flexion and\nulnar-radial movements to recover the joint function of various pathologies\npresented in the Venezuelan population.\n",
"title": "Development of a passive Rehabilitation Robot for the wrist joint through the implementation of an Arduino UNO microcontroller"
}
| null | null |
[
"Computer Science",
"Physics"
] | null | true | null |
16619
| null |
Validated
| null | null |
null |
{
"abstract": " Extremal Graph Theory aims to determine bounds for graph invariants as well\nas the graphs attaining those bounds.\nWe are currently developping PHOEG, an ecosystem of tools designed to help\nresearchers in Extremal Graph Theory.\nIt uses a big relational database of undirected graphs and works with the\nconvex hull of the graphs as points in the invariants space in order to exactly\nobtain the extremal graphs and optimal bounds on the invariants for some fixed\nparameters. The results obtained on the restricted finite class of graphs can\nlater be used to infer conjectures. This database also allows us to make\nqueries on those graphs. Once the conjecture defined, PHOEG goes one step\nfurther by helping in the process of designing a proof guided by successive\napplications of transformations from any graph to an extremal graph. To this\naim, we use a second database based on a graph data model.\nThe paper presents ideas and techniques used in PHOEG to assist the study of\nExtremal Graph Theory.\n",
"title": "PHOEG Helps Obtaining Extremal Graphs"
}
| null | null | null | null | true | null |
16620
| null |
Default
| null | null |
null |
{
"abstract": " We develop an algorithm that forecasts cascading events, by employing a\nGreen's function scheme on the basis of the self-exciting point process model.\nThis method is applied to open data of 10 types of crimes happened in Chicago.\nIt shows a good prediction accuracy superior to or comparable to the standard\nmethods which are the expectation-maximization method and prospective hotspot\nmaps method. We find a cascade influence of the crimes that has a long-time,\nlogarithmic tail; this result is consistent with an earlier study on\nburglaries. This long-tail feature cannot be reproduced by the other standard\nmethods. In addition, a merit of the Green's function method is the low\ncomputational cost in the case of high density of events and/or large amount of\nthe training data.\n",
"title": "Crime Prediction by Data-Driven Green's Function method"
}
| null | null | null | null | true | null |
16621
| null |
Default
| null | null |
null |
{
"abstract": " DZ Cha is a weak-lined T Tauri star (WTTS) surrounded by a bright\nprotoplanetary disc with evidence of inner disc clearing. Its narrow $\\Ha$ line\nand infrared spectral energy distribution suggest that DZ Cha may be a\nphotoevaporating disc. We aim to analyse the DZ Cha star + disc system to\nidentify the mechanism driving the evolution of this object. We have analysed\nthree epochs of high resolution optical spectroscopy, photometry from the UV up\nto the sub-mm regime, infrared spectroscopy, and J-band imaging polarimetry\nobservations of DZ Cha. Combining our analysis with previous studies we find no\nsignatures of accretion in the $\\Ha$ line profile in nine epochs covering a\ntime baseline of $\\sim20$ years. The optical spectra are dominated by\nchromospheric emission lines, but they also show emission from the forbidden\nlines [SII] 4068 and [OI] 6300$\\,\\AA$ that indicate a disc outflow. The\npolarized images reveal a dust depleted cavity of $\\sim7$ au in radius and two\nspiral-like features, and we derive a disc dust mass limit of\n$M_\\mathrm{dust}<3\\MEarth$ from the sub-mm photometry. No stellar ($M_\\star >\n80 \\MJup$) companions are detected down to $0\\farcs07$ ($\\sim 8$ au,\nprojected). The negligible accretion rate, small cavity, and forbidden line\nemission strongly suggests that DZ Cha is currently at the initial stages of\ndisc clearing by photoevaporation. At this point the inner disc has drained and\nthe inner wall of the truncated outer disc is directly exposed to the stellar\nradiation. We argue that other mechanisms like planet formation or binarity\ncannot explain the observed properties of DZ Cha. The scarcity of objects like\nthis one is in line with the dispersal timescale ($\\lesssim 10^5$ yr) predicted\nby this theory. DZ Cha is therefore an ideal target to study the initial stages\nof photoevaporation.\n",
"title": "DZ Cha: a bona fide photoevaporating disc"
}
| null | null | null | null | true | null |
16622
| null |
Default
| null | null |
null |
{
"abstract": " A Bayesian filtering algorithm is developed for a class of state-space\nsystems that can be modelled via Gaussian mixtures. In general, the exact\nsolution to this filtering problem involves an exponential growth in the number\nof mixture terms and this is handled here by utilising a Gaussian mixture\nreduction step after both the time and measurement updates. In addition, a\nsquare-root implementation of the unified algorithm is presented and this\nalgorithm is profiled on several simulated systems. This includes the state\nestimation for two non-linear systems that are strictly outside the class\nconsidered in this paper.\n",
"title": "A Bayesian Filtering Algorithm for Gaussian Mixture Models"
}
| null | null |
[
"Computer Science",
"Statistics"
] | null | true | null |
16623
| null |
Validated
| null | null |
null |
{
"abstract": " We propose a generic algorithmic building block to accelerate training of\nmachine learning models on heterogeneous compute systems. Our scheme allows to\nefficiently employ compute accelerators such as GPUs and FPGAs for the training\nof large-scale machine learning models, when the training data exceeds their\nmemory capacity. Also, it provides adaptivity to any system's memory hierarchy\nin terms of size and processing speed. Our technique is built upon novel\ntheoretical insights regarding primal-dual coordinate methods, and uses duality\ngap information to dynamically decide which part of the data should be made\navailable for fast processing. To illustrate the power of our approach we\ndemonstrate its performance for training of generalized linear models on a\nlarge-scale dataset exceeding the memory size of a modern GPU, showing an\norder-of-magnitude speedup over existing approaches.\n",
"title": "Efficient Use of Limited-Memory Accelerators for Linear Learning on Heterogeneous Systems"
}
| null | null | null | null | true | null |
16624
| null |
Default
| null | null |
null |
{
"abstract": " The past years have shown a remarkable growth in use-cases for micro aerial\nvehicles (MAVs). Conceivable indoor applications require highly robust\nenvironment perception, fast reaction to changing situations, and stable\nnavigation, but reliable sources of absolute positioning like GNSS or compass\nmeasurements are unavailable during indoor flights. We present a\nhigh-performance autonomous inventory MAV for operation inside warehouses. The\nMAV navigates along warehouse aisles and detects the placed stock in the\nshelves alongside its path with a multimodal sensor setup containing an RFID\nreader and two high-resolution cameras. We describe in detail the SLAM pipeline\nbased on a 3D lidar, the setup for stock recognition, the mission planning and\ntrajectory generation, as well as a low-level routine for avoidance of\ndynamical or previously unobserved obstacles. Experiments were performed in an\noperative warehouse of a logistics provider, in which an external warehouse\nmanagement system provided the MAV with high-level inspection missions that are\nexecuted fully autonomously.\n",
"title": "Fast Autonomous Flight in Warehouses for Inventory Applications"
}
| null | null | null | null | true | null |
16625
| null |
Default
| null | null |
null |
{
"abstract": " We construct exact solutions representing a\nFriedmann-Lemaître-Robsertson-Walker (FLRW) universe in a generalized hybrid\nmetric-Palatini theory. By writing the gravitational action in a scalar-tensor\nrepresentation, the new solutions are obtained by either making an ansatz on\nthe scale factor or on the effective potential. Among other relevant results,\nwe show that it is possible to obtain exponentially expanding solutions for\nflat universes even when the cosmology is not purely vacuum. We then derive the\nclasses of actions for the original theory which generate these solutions.\n",
"title": "Cosmological solutions in generalized hybrid metric-Palatini gravity"
}
| null | null |
[
"Physics"
] | null | true | null |
16626
| null |
Validated
| null | null |
null |
{
"abstract": " In this paper, we investigate the robustness to external disturbances of\nswitched discrete and continuous systems with multiple equilibria. It is shown\nthat if each subsystem of the switched system is Input-to-State Stable (ISS),\nthen under switching signals that satisfy an average dwell-time bound, the\nsolutions are ultimately bounded within a compact set. Furthermore, the size of\nthis set varies monotonically with the supremum norm of the disturbance signal.\nIt is observed that when the subsystems share a common equilibrium, ISS is\nrecovered for solutions of the corresponding switched system; hence, the\nresults in this paper are a natural generalization of classical results in\nswitched systems that exhibit a common equilibrium. Additionally, we provide a\nmethod to analytically compute the average dwell time if each subsystem\npossesses a quadratic ISS-Lyapunov function. Our motivation for studying this\nclass of switched systems arises from certain motion planning problems in\nrobotics, where primitive motions, each corresponding to an equilibrium point\nof a dynamical system, must be composed to realize a task. However, the results\nare relevant to a much broader class of applications, in which composition of\ndifferent modes of behavior is required.\n",
"title": "Ultimate Boundedness for Switched Systems with Multiple Equilibria Under Disturbances"
}
| null | null | null | null | true | null |
16627
| null |
Default
| null | null |
null |
{
"abstract": " The singular value matrix decomposition plays a ubiquitous role throughout\nstatistics and related fields. Myriad applications including clustering,\nclassification, and dimensionality reduction involve studying and exploiting\nthe geometric structure of singular values and singular vectors.\nThis paper provides a novel collection of technical and theoretical tools for\nstudying the geometry of singular subspaces using the two-to-infinity norm.\nMotivated by preliminary deterministic Procrustes analysis, we consider a\ngeneral matrix perturbation setting in which we derive a new Procrustean matrix\ndecomposition. Together with flexible machinery developed for the\ntwo-to-infinity norm, this allows us to conduct a refined analysis of the\ninduced perturbation geometry with respect to the underlying singular vectors\neven in the presence of singular value multiplicity. Our analysis yields\nsingular vector entrywise perturbation bounds for a range of popular matrix\nnoise models, each of which has a meaningful associated statistical inference\ntask. In addition, we demonstrate how the two-to-infinity norm is the preferred\nnorm in certain statistical settings. Specific applications discussed in this\npaper include covariance estimation, singular subspace recovery, and multiple\ngraph inference.\nBoth our Procrustean matrix decomposition and the technical machinery\ndeveloped for the two-to-infinity norm may be of independent interest.\n",
"title": "The two-to-infinity norm and singular subspace geometry with applications to high-dimensional statistics"
}
| null | null |
[
"Mathematics",
"Statistics"
] | null | true | null |
16628
| null |
Validated
| null | null |
null |
{
"abstract": " Complex network reconstruction is a hot topic in many fields. A popular\ndata-driven reconstruction framework is based on lasso. However, it is found\nthat, in the presence of noise, it may be inefficient for lasso to determine\nthe network topology. This paper builds a new framework to cope with this\nproblem. The key idea is to employ a series of linear regression problems to\nmodel the relationship between network nodes, and then to use an efficient\nvariational Bayesian method to infer the unknown coefficients. Based on the\nobtained information, the network is finally reconstructed by determining\nwhether two nodes connect with each other or not. The numerical experiments\nconducted with both synthetic and real data demonstrate that the new method\noutperforms lasso with regard to both reconstruction accuracy and running\nspeed.\n",
"title": "Variational Bayesian Complex Network Reconstruction"
}
| null | null | null | null | true | null |
16629
| null |
Default
| null | null |
null |
{
"abstract": " We study the two-dimensional stochastic nonlinear wave equations (SNLW) with\nan additive space-time white noise forcing. In particular, we introduce a\ntime-dependent renor- malization and prove that SNLW is pathwise locally\nwell-posed. As an application of the local well-posedness argument, we also\nestablish a weak universality result for the renormalized SNLW.\n",
"title": "Renormalization of the two-dimensional stochastic nonlinear wave equations"
}
| null | null |
[
"Mathematics"
] | null | true | null |
16630
| null |
Validated
| null | null |
null |
{
"abstract": " Twisted electromagnetic waves, of which the helical phase front is called\norbital angular momentum (OAM), have been recently explored for quantum\ninformation, high speed communication and radar detections. In this context,\ngeneration of high purity waves carrying OAM is of great significance and\nchallenge from low frequency band to optical area. Here, a novel strategy of\nmode combination method is proposed to generate twisted waves with arbitrary\norder of OAM index. The higher order mode of a circular horn antenna is used to\ngenerate the twisted waves with quite high purity. The proposed strategy is\nverified with theoretical analysis, numerical simulation and experiments. A\ncircular horn antenna operating at millimeter wave band is designed,\nfabricated, and measured. Two twisted waves with OAM index of l=+1 and l=-1\nwith a mode purity as high as 87% are obtained. Compared with the other OAM\nantennas, the antenna proposed here owns a high antenna gain (over 12 dBi) and\nwide operating bandwidth (over 15%). The high mode purity, high antenna gain\nand wide operating band make the antenna suitable for the twisted-wave\napplications, not only in the microwave and millimeter wave band, but also in\nthe terahertz band.\n",
"title": "Generation of High-Purity Millimeter-Wave Orbital Angular Momentum Modes Using Horn Antenna: Theory and Implementation"
}
| null | null |
[
"Physics"
] | null | true | null |
16631
| null |
Validated
| null | null |
null |
{
"abstract": " Effective file transfer between vehicles is fundamental to many emerging\nvehicular infotainment applications in the highway Vehicular Ad Hoc Networks\n(VANETs), such as content distribution and social networking. However, due to\nfast mobility, the connection between vehicles tends to be short-lived and\nlossy, which makes intact file transfer extremely challenging. To tackle this\nproblem, we presents a novel Cluster-based File Transfer (CFT) scheme for\nhighway VANETs in this paper. With CFT, when a vehicle requests a file, the\ntransmission capacity between the resource vehicle and the destination vehicle\nis evaluated. If the requested file can be successfully transferred over the\ndirect Vehicular-to-Vehicular (V2V) connection, the file transfer will be\ncompleted by the resource and the destination themselves. Otherwise, a cluster\nwill be formed to help the file transfer. As a fully-distributed scheme that\nrelies on the collaboration of cluster members, CFT does not require any\nassistance from roadside units or access points. Our experimental results\nindicate that CFT outperforms the existing file transfer schemes for highway\nVANETs.\n",
"title": "CFT: A Cluster-based File Transfer Scheme for Highway"
}
| null | null |
[
"Computer Science"
] | null | true | null |
16632
| null |
Validated
| null | null |
null |
{
"abstract": " In a Bayesian context, prior specification for inference on monotone\ndensities is conceptually straightforward, but proving posterior convergence\ntheorems is complicated by the fact that desirable prior concentration\nproperties often are not satisfied. In this paper, I first develop a new prior\ndesigned specifically to satisfy an empirical version of the prior\nconcentration property, and then I give sufficient conditions on the prior\ninputs such that the corresponding empirical Bayes posterior concentrates\naround the true monotone density at nearly the optimal minimax rate. Numerical\nillustrations also reveal the practical benefits of the proposed empirical\nBayes approach compared to Dirichlet process mixtures.\n",
"title": "Empirical priors and posterior concentration rates for a monotone density"
}
| null | null | null | null | true | null |
16633
| null |
Default
| null | null |
null |
{
"abstract": " We consider the problem of automated assignment of papers to reviewers in\nconference peer review, with a focus on fairness and statistical accuracy. Our\nfairness objective is to maximize the review quality of the most disadvantaged\npaper, in contrast to the commonly used objective of maximizing the total\nquality over all papers. We design an assignment algorithm based on an\nincremental max-flow procedure that we prove is near-optimally fair. Our\nstatistical accuracy objective is to ensure correct recovery of the papers that\nshould be accepted. We provide a sharp minimax analysis of the accuracy of the\npeer-review process for a popular objective-score model as well as for a novel\nsubjective-score model that we propose in the paper. Our analysis proves that\nour proposed assignment algorithm also leads to a near-optimal statistical\naccuracy. Finally, we design a novel experiment that allows for an objective\ncomparison of various assignment algorithms, and overcomes the inherent\ndifficulty posed by the absence of a ground truth in experiments on\npeer-review. The results of this experiment corroborate the theoretical\nguarantees of our algorithm.\n",
"title": "PeerReview4All: Fair and Accurate Reviewer Assignment in Peer Review"
}
| null | null | null | null | true | null |
16634
| null |
Default
| null | null |
null |
{
"abstract": " Regularization methods are commonly used in X-ray CT image reconstruction.\nDifferent regularization methods reflect the characterization of different\nprior knowledge of images. In a recent work, a new regularization method called\na low-dimensional manifold model (LDMM) is investigated to characterize the\nlow-dimensional patch manifold structure of natural images, where the manifold\ndimensionality characterizes structural information of an image. In this paper,\nwe propose a CT image reconstruction method based on the prior knowledge of the\nlow-dimensional manifold of CT image. Using the clinical raw projection data\nfrom GE clinic, we conduct comparisons for the CT image reconstruction among\nthe proposed method, the simultaneous algebraic reconstruction technique (SART)\nwith the total variation (TV) regularization, and the filtered back projection\n(FBP) method. Results show that the proposed method can successfully recover\nstructural details of an imaging object, and achieve higher spatial and\ncontrast resolution of the reconstructed image than counterparts of FBP and\nSART with TV.\n",
"title": "CT Image Reconstruction in a Low Dimensional Manifold"
}
| null | null | null | null | true | null |
16635
| null |
Default
| null | null |
null |
{
"abstract": " Unsupervised clustering is one of the most fundamental challenges in machine\nlearning. A popular hypothesis is that data are generated from a union of\nlow-dimensional nonlinear manifolds; thus an approach to clustering is\nidentifying and separating these manifolds. In this paper, we present a novel\napproach to solve this problem by using a mixture of autoencoders. Our model\nconsists of two parts: 1) a collection of autoencoders where each autoencoder\nlearns the underlying manifold of a group of similar objects, and 2) a mixture\nassignment neural network, which takes the concatenated latent vectors from the\nautoencoders as input and infers the distribution over clusters. By jointly\noptimizing the two parts, we simultaneously assign data to clusters and learn\nthe underlying manifolds of each cluster.\n",
"title": "Deep Unsupervised Clustering Using Mixture of Autoencoders"
}
| null | null | null | null | true | null |
16636
| null |
Default
| null | null |
null |
{
"abstract": " The Pepper robot has become a widely recognised face for the perceived\npotential of social robots to enter our homes and businesses. However, to date,\ncommercial and research applications of the Pepper have been largely restricted\nto roles in which the robot is able to remain stationary. This restriction is\nthe result of a number of technical limitations, including limited sensing\ncapabilities, and have as a result, reduced the number of roles in which use of\nthe robot can be explored. In this paper, we present our approach to solving\nthese problems, with the intention of opening up new research applications for\nthe robot. To demonstrate the applicability of our approach, we have framed\nthis work within the context of providing interactive tours of an open-plan\nrobotics laboratory.\n",
"title": "Enabling a Pepper Robot to provide Automated and Interactive Tours of a Robotics Laboratory"
}
| null | null | null | null | true | null |
16637
| null |
Default
| null | null |
null |
{
"abstract": " The ensemble Kalman filter (EnKF) is a Monte Carlo based implementation of\nthe Kalman filter (KF) for extremely high-dimensional, possibly nonlinear and\nnon-Gaussian state estimation problems. Its ability to handle state dimensions\nin the order of millions has made the EnKF a popular algorithm in different\ngeoscientific disciplines. Despite a similarly vital need for scalable\nalgorithms in signal processing, e.g., to make sense of the ever increasing\namount of sensor data, the EnKF is hardly discussed in our field.\nThis self-contained review paper is aimed at signal processing researchers\nand provides all the knowledge to get started with the EnKF. The algorithm is\nderived in a KF framework, without the often encountered geoscientific\nterminology. Algorithmic challenges and required extensions of the EnKF are\nprovided, as well as relations to sigma-point KF and particle filters. The\nrelevant EnKF literature is summarized in an extensive survey and unique\nsimulation examples, including popular benchmark problems, complement the\ntheory with practical insights. The signal processing perspective highlights\nnew directions of research and facilitates the exchange of potentially\nbeneficial ideas, both for the EnKF and high-dimensional nonlinear and\nnon-Gaussian filtering in general.\n",
"title": "The Ensemble Kalman Filter: A Signal Processing Perspective"
}
| null | null | null | null | true | null |
16638
| null |
Default
| null | null |
null |
{
"abstract": " Full-duplex (FD) technology is likely to be adopted in various legacy\ncommunications standards. The IEEE 802.11ax working group has been considering\na simultaneous transmit and receive (STR) mode for the next generation wireless\nlocal area networks (WLANs). Enabling STR mode (FD communication mode) in\n802.11 networks creates bi-directional FD (BFD) and uni-directional FD (UFD)\nlinks. The key challenge is to integrate STR mode with minimal protocol\nmodifications, while considering the co-existence of FD and legacy half-duplex\n(HD) stations (STAs) and backwards compatibility. This paper proposes a simple\nand practical approach to enable STR mode in 802.11 networks with co-existing\nFD and HD STAs. The protocol explicitly accounts for the peculiarities of FD\nenvironments and backwards compatibility. Key aspects of the proposed solution\ninclude FD capability discovery, handshake mechanism for channel access, node\nselection for UFD transmission, adaptive acknowledgement (ACK) timeout for STAs\nengaged in BFD or UFD transmission, and mitigation of contention unfairness.\nPerformance evaluation demonstrates the effectiveness of the proposed solution\nin realizing the gains of FD technology for next generation WLANs.\n",
"title": "Simultaneous Transmit and Receive Operation in Next Generation IEEE 802.11 WLANs: A MAC Protocol Design Approach"
}
| null | null | null | null | true | null |
16639
| null |
Default
| null | null |
null |
{
"abstract": " Unmanned Aerial Vehicles (UAVs) have recently shown great performance\ncollecting visual data through autonomous exploration and mapping in building\ninspection. Yet, the number of studies is limited considering the post\nprocessing of the data and its integration with autonomous UAVs. These will\nenable huge steps onward into full automation of building inspection. In this\nregard, this work presents a decision making tool for revisiting tasks in\nvisual building inspection by autonomous UAVs. The tool is an implementation of\nfine-tuning a pretrained Convolutional Neural Network (CNN) for surface crack\ndetection. It offers an optional mechanism for task planning of revisiting\npinpoint locations during inspection. It is integrated to a quadrotor UAV\nsystem that can autonomously navigate in GPS-denied environments. The UAV is\nequipped with onboard sensors and computers for autonomous localization,\nmapping and motion planning. The integrated system is tested through\nsimulations and real-world experiments. The results show that the system\nachieves crack detection and autonomous navigation in GPS-denied environments\nfor building inspection.\n",
"title": "Transfer Learning-Based Crack Detection by Autonomous UAVs"
}
| null | null | null | null | true | null |
16640
| null |
Default
| null | null |
null |
{
"abstract": " In this paper we give an infinite family of strings for which the length of\nthe Lempel-Ziv'77 parse is a factor $\\Omega(\\log n/\\log\\log n)$ smaller than\nthe smallest run-length grammar.\n",
"title": "A Separation Between Run-Length SLPs and LZ77"
}
| null | null | null | null | true | null |
16641
| null |
Default
| null | null |
null |
{
"abstract": " Tactile sensing can enable a robot to infer properties of its surroundings,\nsuch as the material of an object. Heat transfer based sensing can be used for\nmaterial recognition due to differences in the thermal properties of materials.\nWhile data-driven methods have shown promise for this recognition problem, many\nfactors can influence performance, including sensor noise, the initial\ntemperatures of the sensor and the object, the thermal effusivities of the\nmaterials, and the duration of contact. We present a physics-based mathematical\nmodel that predicts material recognition performance given these factors. Our\nmodel uses semi-infinite solids and a statistical method to calculate an F1\nscore for the binary material recognition. We evaluated our method using\nsimulated contact with 69 materials and data collected by a real robot with 12\nmaterials. Our model predicted the material recognition performance of support\nvector machine (SVM) with 96% accuracy for the simulated data, with 92%\naccuracy for real-world data with constant initial sensor temperatures, and\nwith 91% accuracy for real-world data with varied initial sensor temperatures.\nUsing our model, we also provide insight into the roles of various factors on\nrecognition performance, such as the temperature difference between the sensor\nand the object. Overall, our results suggest that our model could be used to\nhelp design better thermal sensors for robots and enable robots to use them\nmore effectively.\n",
"title": "A Model that Predicts the Material Recognition Performance of Thermal Tactile Sensing"
}
| null | null |
[
"Computer Science"
] | null | true | null |
16642
| null |
Validated
| null | null |
null |
{
"abstract": " Safe interaction with human drivers is one of the primary challenges for\nautonomous vehicles. In order to plan driving maneuvers effectively, the\nvehicle's control system must infer and predict how humans will behave based on\ntheir latent internal state (e.g., intentions and aggressiveness). This\nresearch uses a simple model for human behavior with unknown parameters that\nmake up the internal states of the traffic participants and presents a method\nfor quantifying the value of estimating these states and planning with their\nuncertainty explicitly modeled. An upper performance bound is established by an\nomniscient Monte Carlo Tree Search (MCTS) planner that has perfect knowledge of\nthe internal states. A baseline lower bound is established by planning with\nMCTS assuming that all drivers have the same internal state. MCTS variants are\nthen used to solve a partially observable Markov decision process (POMDP) that\nmodels the internal state uncertainty to determine whether inferring the\ninternal state offers an advantage over the baseline. Applying this method to a\nfreeway lane changing scenario reveals that there is a significant performance\ngap between the upper bound and baseline. POMDP planning techniques come close\nto closing this gap, especially when important hidden model parameters are\ncorrelated with measurable parameters.\n",
"title": "The Value of Inferring the Internal State of Traffic Participants for Autonomous Freeway Driving"
}
| null | null |
[
"Computer Science"
] | null | true | null |
16643
| null |
Validated
| null | null |
null |
{
"abstract": " In this paper, we consider the final state problem for the nonlinear\nSchrödinger equation with a homogeneous nonlinearity of the critical order\nwhich is not necessarily a polynomial. In [10], the first and the second\nauthors consider one- and two-dimensional cases and gave a sufficient condition\non the nonlinearity for that the corresponding equation admits a solution that\nbehaves like a free solution with or without a logarithmic phase correction.\nThe present paper is devoted to the study of the three-dimensional case, in\nwhich it is required that a solution converges to a given asymptotic profile in\na faster rate than in the lower dimensional cases. To obtain the necessary\nconvergence rate, we employ the end-point Strichartz estimate and modify a\ntime-dependent regularizing operator, introduced in [10]. Moreover, we present\na candidate of the second asymptotic profile to the solution.\n",
"title": "Long range scattering for nonlinear Schrödinger equations with critical homogeneous nonlinearity in three space dimensions"
}
| null | null | null | null | true | null |
16644
| null |
Default
| null | null |
null |
{
"abstract": " When performing localization and mapping, working at the level of structure\ncan be advantageous in terms of robustness to environmental changes and\ndifferences in illumination. This paper presents SegMap: a map representation\nsolution to the localization and mapping problem based on the extraction of\nsegments in 3D point clouds. In addition to facilitating the computationally\nintensive task of processing 3D point clouds, working at the level of segments\naddresses the data compression requirements of real-time single- and\nmulti-robot systems. While current methods extract descriptors for the single\ntask of localization, SegMap leverages a data-driven descriptor in order to\nextract meaningful features that can also be used for reconstructing a dense 3D\nmap of the environment and for extracting semantic information. This is\nparticularly interesting for navigation tasks and for providing visual feedback\nto end-users such as robot operators, for example in search and rescue\nscenarios. These capabilities are demonstrated in multiple urban driving and\nsearch and rescue experiments. Our method leads to an increase of area under\nthe ROC curve of 28.3% over current state of the art using eigenvalue based\nfeatures. We also obtain very similar reconstruction capabilities to a model\nspecifically trained for this task. The SegMap implementation will be made\navailable open-source along with easy to run demonstrations at\nwww.github.com/ethz-asl/segmap. A video demonstration is available at\nthis https URL.\n",
"title": "SegMap: 3D Segment Mapping using Data-Driven Descriptors"
}
| null | null | null | null | true | null |
16645
| null |
Default
| null | null |
null |
{
"abstract": " We prove that for a generic Lefschetz pencil of plane curves of degree $d\\geq\n3$ there exists a curve $H$ (called the Hesse curve of the pencil) of degree\n$6(d-1)$ and genus $3(4d^2-13d+8)+1$, and such that: $(i)$ $H$ has $d^2$\nsingular points of multiplicity three at the base points of the pencil and\n$3(d-1)^2$ ordinary nodes at the singular points of the degenerate members of\nthe pencil; $(ii)$ for each member of the pencil the intersection of $H$ with\nthis fibre consists of the inflection points of this member and the base points\nof the pencil.\n",
"title": "The Hesse curve of a Lefschtz pencil of plane curves"
}
| null | null | null | null | true | null |
16646
| null |
Default
| null | null |
null |
{
"abstract": " Many state of the art methods for the thermodynamic and kinetic\ncharacterization of large and complex biomolecular systems by simulation rely\non ensemble approaches, where data from large numbers of relatively short\ntrajectories are integrated. In this context, Markov state models (MSMs) are\nextremely popular because they can be used to compute stationary quantities and\nlong-time kinetics from ensembles of short simulations, provided that these\nshort simulations are in \"local equilibrium\" within the MSM states. However, in\nthe last over 15 years since the inception of MSMs, it has been controversially\ndiscussed and not yet been answered how deviations from local equilibrium can\nbe detected, whether these deviations induce a practical bias in MSM\nestimation, and how to correct for them. In this paper, we address these\nissues: We systematically analyze the estimation of Markov state models (MSMs)\nfrom short non-equilibrium simulations, and we provide an expression for the\nerror between unbiased transition probabilities and the expected estimate from\nmany short simulations. We show that the unbiased MSM estimate can be obtained\neven from relatively short non-equilibrium simulations in the limit of long lag\ntimes and good discretization. Further, we exploit observable operator model\n(OOM) theory to derive an unbiased estimator for the MSM transition matrix that\ncorrects for the effect of starting out of equilibrium, even when short lag\ntimes are used. Finally, we show how the OOM framework can be used to estimate\nthe exact eigenvalues or relaxation timescales of the system without estimating\nan MSM transition matrix, which allows us to practically assess the\ndiscretization quality of the MSM. Applications to model systems and molecular\ndynamics simulation data of alanine dipeptide are included for illustration.\nThe improved MSM estimator is implemented in PyEMMA as of version 2.3.\n",
"title": "Markov State Models from short non-Equilibrium Simulations - Analysis and Correction of Estimation Bias"
}
| null | null | null | null | true | null |
16647
| null |
Default
| null | null |
null |
{
"abstract": " We construct, for any finite commutative ring $R$, a family of\nrepresentations of the general linear group $\\mathrm{GL}_n(R)$ whose\nintertwining properties mirror those of the principal series for\n$\\mathrm{GL}_n$ over a finite field.\n",
"title": "Principal series for general linear groups over finite commutative rings"
}
| null | null | null | null | true | null |
16648
| null |
Default
| null | null |
null |
{
"abstract": " The LZ dark matter detector, like many other rare-event searches, will suffer\nfrom backgrounds due to the radioactive decay of radon daughters. In order to\nachieve its science goals, the concentration of radon within the xenon should\nnot exceed $2\\mu$Bq/kg, or 20 mBq total within its 10 tonnes. The LZ\ncollaboration is in the midst of a program to screen all significant components\nin contact with the xenon. The four institutions involved in this effort have\nbegun sharing two cross-calibration sources to ensure consistent measurement\nresults across multiple distinct devices. We present here five preliminary\nscreening results, some mitigation strategies that will reduce the amount of\nradon produced by the most problematic components, and a summary of the current\nestimate of radon emanation throughout the detector. This best estimate totals\n$<17.3$ mBq, sufficiently low to meet the detector's science goals.\n",
"title": "Constraining Radon Backgrounds in LZ"
}
| null | null |
[
"Physics"
] | null | true | null |
16649
| null |
Validated
| null | null |
null |
{
"abstract": " We present models for single-particle dispersion in vertical and horizontal\ndirections of stably stratified flows. The model in the vertical direction is\nbased on the observed Lagrangian spectrum of the vertical velocity, while the\nmodel in the horizontal direction is a combination of a continuous-time\neddy-constrained random walk process with a contribution to transport from\nhorizontal winds. Transport at times larger than the Lagrangian turnover time\nis not universal and dependent on these winds. The models yield results in good\nagreement with direct numerical simulations of stratified turbulence, for which\nsingle-particle dispersion differs from the well studied case of homogeneous\nand isotropic turbulence.\n",
"title": "Single-particle dispersion in stably stratified turbulence"
}
| null | null | null | null | true | null |
16650
| null |
Default
| null | null |
null |
{
"abstract": " Microcolonies are aggregates of a few dozen to a few thousand cells exhibited\nby many bacteria. The formation of microcolonies is a crucial step towards the\nformation of more mature bacterial communities known as biofilms, but also\nmarks a significant change in bacterial physiology. Within a microcolony,\nbacteria forgo a single cell lifestyle for a communal lifestyle hallmarked by\nhigh cell density and physical interactions between cells potentially altering\ntheir behaviour. It is thus crucial to understand how initially identical\nsingle cells start to behave differently while assembling in these tight\ncommunities. Here we show that cells in the microcolonies formed by the human\npathogen Neisseria gonorrhoeae (Ng) present differential motility behaviors\nwithin an hour upon colony formation. Observation of merging microcolonies and\ntracking of single cells within microcolonies reveal a heterogeneous motility\nbehavior: cells close to the surface of the microcolony exhibit a much higher\nmotility compared to cells towards the center. Numerical simulations of a\nbiophysical model for the microcolonies at the single cell level suggest that\nthe emergence of differential behavior within a multicellular microcolony of\notherwise identical cells is of mechanical origin. It could suggest a route\ntoward further bacterial differentiation and ultimately mature biofilms.\n",
"title": "Pili mediated intercellular forces shape heterogeneous bacterial microcolonies prior to multicellular differentiation"
}
| null | null | null | null | true | null |
16651
| null |
Default
| null | null |
null |
{
"abstract": " Estimators computed from adaptively collected data do not behave like their\nnon-adaptive brethren. Rather, the sequential dependence of the collection\npolicy can lead to severe distributional biases that persist even in the\ninfinite data limit. We develop a general method -- $\\mathbf{W}$-decorrelation\n-- for transforming the bias of adaptive linear regression estimators into\nvariance. The method uses only coarse-grained information about the data\ncollection policy and does not need access to propensity scores or exact\nknowledge of the policy. We bound the finite-sample bias and variance of the\n$\\mathbf{W}$-estimator and develop asymptotically correct confidence intervals\nbased on a novel martingale central limit theorem. We then demonstrate the\nempirical benefits of the generic $\\mathbf{W}$-decorrelation procedure in two\ndifferent adaptive data settings: the multi-armed bandit and the autoregressive\ntime series.\n",
"title": "Accurate Inference for Adaptive Linear Models"
}
| null | null | null | null | true | null |
16652
| null |
Default
| null | null |
null |
{
"abstract": " Alignment of curve data is an integral part of their statistical analysis,\nand can be achieved using model- or optimization-based approaches. The\nparameter space is usually the set of monotone, continuous warp maps of a\ndomain. Infinite-dimensional nature of the parameter space encourages sampling\nbased approaches, which require a distribution on the set of warp maps.\nMoreover, the distribution should also enable sampling in the presence of\nimportant landmark information on the curves which constrain the warp maps. For\nalignment of closed and open curves in $\\mathbb{R}^d, d=1,2,3$, possibly with\nlandmark information, we provide a constructive, point-process based definition\nof a distribution on the set of warp maps of $[0,1]$ and the unit circle\n$\\mathbb{S}^1$ that is (1) simple to sample from, and (2) possesses the\ndesiderata for decomposition of the alignment problem with landmark constraints\ninto multiple unconstrained ones. For warp maps on $[0,1]$, the distribution is\nrelated to the Dirichlet process. We demonstrate its utility by using it as a\nprior distribution on warp maps in a Bayesian model for alignment of two\nunivariate curves, and as a proposal distribution in a stochastic algorithm\nthat optimizes a suitable alignment functional for higher-dimensional curves.\nSeveral examples from simulated and real datasets are provided.\n",
"title": "Distribution on Warp Maps for Alignment of Open and Closed Curves"
}
| null | null | null | null | true | null |
16653
| null |
Default
| null | null |
null |
{
"abstract": " We introduce a new class of sequential Monte Carlo methods called Nested\nSampling via Sequential Monte Carlo (NS-SMC), which reframes the Nested\nSampling method of Skilling (2006) in terms of sequential Monte Carlo\ntechniques. This new framework allows convergence results to be obtained in the\nsetting when Markov chain Monte Carlo (MCMC) is used to produce new samples. An\nadditional benefit is that marginal likelihood estimates are unbiased. In\ncontrast to NS, the analysis of NS-SMC does not require the (unrealistic)\nassumption that the simulated samples be independent. As the original NS\nalgorithm is a special case of NS-SMC, this provides insights as to why NS\nseems to produce accurate estimates despite a typical violation of its\nassumptions. For applications of NS-SMC, we give advice on tuning MCMC kernels\nin an automated manner via a preliminary pilot run, and present a new method\nfor appropriately choosing the number of MCMC repeats at each iteration.\nFinally, a numerical study is conducted where the performance of NS-SMC and\ntemperature-annealed SMC is compared on several challenging and realistic\nproblems. MATLAB code for our experiments is made available at\nthis https URL .\n",
"title": "Unbiased and Consistent Nested Sampling via Sequential Monte Carlo"
}
| null | null | null | null | true | null |
16654
| null |
Default
| null | null |
null |
{
"abstract": " The classical Cuntz semigroup has an important role in the study of\nC*-algebras, being one of the main invariants used to classify recalcitrant\nC*-algebras up to isomorphism. We consider C*-algebras that have Hopf algebra\nstructure, and find additional structure in their Cuntz semigroups, thus\ngeneralizing the equivariant Cuntz semigroup. We develop various aspects of the\ntheory of such semigroups, and in particular, we give general results allowing\nclassification results of the Elliott classification program to be extended to\nclassification results for C*-algebraic quantum groups.\n",
"title": "Cuntz semigroups of compact-type Hopf C*-algebras"
}
| null | null | null | null | true | null |
16655
| null |
Default
| null | null |
null |
{
"abstract": " As of 2014, 54% of the earth's population resides in urban areas, and it is\nsteadily increasing, expecting to reach 66% by 2050. Urban areas range from\nsmall cities with tens of thousands of people to megacities with greater than\n10 million people. Roughly 12% of the global population today lives in 28\nmegacities, and at least 40 are projected by 2030. At these scales, the urban\ninfrastructure such as roads, buildings, and utility networks will cover areas\nas large as New England. This steady urbanization and the resulting expansion\nof infrastructure, combined with renewal of aging urban infrastructure,\nrepresent tens of trillion of dollars in new urban infrastructure investment\nover the coming decades. These investments must balance factors including\nimpact on clean air and water, energy and maintenance costs, and the\nproductivity and health of city dwellers. Moreover, cost-effective management\nand sustainability of these growing urban areas will be one of the most\ncritical challenges to our society, motivating the concept of science- and\ndata-driven urban design, retrofit, and operation-that is, \"Smart Cities\".\n",
"title": "City-Scale Intelligent Systems and Platforms"
}
| null | null | null | null | true | null |
16656
| null |
Default
| null | null |
null |
{
"abstract": " Direct comparison of areal and profile roughness measurement values is not\nadvisable due to fundamental differences in the measurement techniques. However\nresearchers may wish to compare between laboratories with differing equipment,\nor against literature values. This paper investigates how well the profile\narithmetic mean average roughness, $R_a$, approximates its areal equivalent\n$S_a$. Simulated rough surfaces and samples from the ETOPO1 global relief model\nwere used. The mean of up to 20 $R_a$ profiles from the surface were compared\nwith surface $S_a$ for 100 repeats. Differences between $\\bar{R_a}$ and $S_a$\nfell as the number of $R_a$ values averaged increased. For simulated surfaces\nmean % difference between $\\bar{R_a}$ and $S_a$ was in the range 16.06% to\n3.47% when only one $R_a$ profile was taken. By averaging 20 $R_a$ values mean\n% difference fell to 6.60% to 0.81%. By not considering $R_a$ profiles parallel\nto the main feature direction (identified visually), mean % difference was\nfurther reduced. For ETOPO1 global relief surfaces mean % difference was in the\nrange 52.09% to 22.60% when only one $R_a$ value was used, and was 33.22% to\n9.90% when 20 $R_a$ values were averaged. Where a surface feature direction\ncould be identified, accounting for reduced the difference between $\\bar{R_a}$\nand $S_a$ by approximately 5% points. The results suggest that taking the mean\nof between 3 and 5 $R_a$ values will give a good estimate of $S_a$ on regular\nor simple surfaces. However, for some complex real world surfaces discrepancy\nbetween $\\bar{R_a}$ and $S_a$ are high. Caveats including the use of filters\nfor areal and profile measurements, and profile alignment are discussed.\n",
"title": "A simulated comparison between profile and areal surface parameters: $R_a$ as an estimate of $S_a$"
}
| null | null | null | null | true | null |
16657
| null |
Default
| null | null |
null |
{
"abstract": " We present the VLA-COSMOS 3 GHz Large Project based on 384 hours of\nobservations with the Karl G. Jansky Very Large Array (VLA) at 3 GHz (10 cm)\ntoward the two square degree Cosmic Evolution Survey (COSMOS) field. The final\nmosaic reaches a median rms of 2.3 uJy/beam over the two square degrees at an\nangular resolution of 0.75\". To fully account for the spectral shape and\nresolution variations across the broad (2 GHz) band, we image all data with a\nmultiscale, multifrequency synthesis algorithm. We present a catalog of 10,830\nradio sources down to 5 sigma, out of which 67 are combined from multiple\ncomponents. Comparing the positions of our 3 GHz sources with those from the\nVery Long Baseline Array (VLBA)-COSMOS survey, we estimate that the astrometry\nis accurate to 0.01\" at the bright end (signal-to-noise ratio, S/N_3GHz > 20).\nSurvival analysis on our data combined with the VLA-COSMOS 1.4~GHz Joint\nProject catalog yields an expected median radio spectral index of alpha=-0.7.\nWe compute completeness corrections via Monte Carlo simulations to derive the\ncorrected 3 GHz source counts. Our counts are in agreement with previously\nderived 3 GHz counts based on single-pointing (0.087 square degrees) VLA data.\nIn summary, the VLA-COSMOS 3 GHz Large Project simultaneously provides the\nlargest and deepest radio continuum survey at high (0.75\") angular resolution\nto date, bridging the gap between last-generation and next-generation surveys.\n",
"title": "The VLA-COSMOS 3 GHz Large Project: Continuum data and source catalog release"
}
| null | null | null | null | true | null |
16658
| null |
Default
| null | null |
null |
{
"abstract": " Point source detection at low signal-to-noise is challenging for astronomical\nsurveys, particularly in radio interferometry images where the noise is\ncorrelated. Machine learning is a promising solution, allowing the development\nof algorithms tailored to specific telescope arrays and science cases. We\npresent DeepSource - a deep learning solution - that uses convolutional neural\nnetworks to achieve these goals. DeepSource enhances the Signal-to-Noise Ratio\n(SNR) of the original map and then uses dynamic blob detection to detect\nsources. Trained and tested on two sets of 500 simulated 1 deg x 1 deg MeerKAT\nimages with a total of 300,000 sources, DeepSource is essentially perfect in\nboth purity and completeness down to SNR = 4 and outperforms PyBDSF in all\nmetrics. For uniformly-weighted images it achieves a Purity x Completeness (PC)\nscore at SNR = 3 of 0.73, compared to 0.31 for the best PyBDSF model. For\nnatural-weighting we find a smaller improvement of ~40% in the PC score at SNR\n= 3. If instead we ask where either of the purity or completeness first drop to\n90%, we find that DeepSource reaches this value at SNR = 3.6 compared to the\n4.3 of PyBDSF (natural-weighting). A key advantage of DeepSource is that it can\nlearn to optimally trade off purity and completeness for any science case under\nconsideration. Our results show that deep learning is a promising approach to\npoint source detection in astronomical images.\n",
"title": "DeepSource: Point Source Detection using Deep Learning"
}
| null | null | null | null | true | null |
16659
| null |
Default
| null | null |
null |
{
"abstract": " Co-design conditions for the design of a jumping-rule and a sampled-data\ncontrol law for impulsive and impulsive switched systems subject to aperiodic\nsampled-data measurements are provided. Semi-infinite discrete-time\nLyapunov-Metzler conditions are first obtained. As these conditions are\ndifficult to check and generalize to more complex systems, an equivalent\nformulation is provided in terms of clock-dependent (infinite-dimensional)\nmatrix inequalities. These conditions are then, in turn, approximated by a\nfinite-dimensional optimization problem using a sum of squares based\nrelaxation. It is proven that the sum of squares relaxation is non conservative\nprovided that the degree of the polynomials is sufficiently large. It is\nemphasized that acceptable results are obtained for low polynomial degrees in\nthe considered examples.\n",
"title": "Co-design of aperiodic sampled-data min-jumping rules for linear impulsive, switched impulsive and sampled-data systems"
}
| null | null | null | null | true | null |
16660
| null |
Default
| null | null |
null |
{
"abstract": " We study the ground state of a one-dimensional (1D) trapped Bose gas with two\nmobile impurity particles. To investigate this set-up, we develop a variational\nprocedure in which the coordinates of the impurity particles are slow-like\nvariables. We validate our method using the exact results obtained for small\nsystems. Then, we discuss energies and pair densities for systems that contain\nof the order of one hundred atoms. We show that bosonic non-interacting\nimpurities cluster. To explain this clustering, we calculate and discuss\ninduced impurity-impurity potentials in a harmonic trap. Further, we compute\nthe force between static impurities in a ring ({\\it {à} la} the Casimir\nforce), and contrast the two effective potentials: the one obtained from the\nmean-field approximation, and the one due to the one-phonon exchange. Our\nformalism and findings are important for understanding (beyond the polaron\nmodel) the physics of modern 1D cold-atom systems with more than one impurity.\n",
"title": "Coalescence of Two Impurities in a Trapped One-dimensional Bose Gas"
}
| null | null | null | null | true | null |
16661
| null |
Default
| null | null |
null |
{
"abstract": " Rust represents a major advancement in production programming languages\nbecause of its success in bridging the gap between high-level application\nprogramming and low-level systems programming. At the heart of its design lies\na novel approach to ownership that remains highly programmable.\nIn this talk, we will describe our ongoing work on designing a formal\nsemantics for Rust that captures ownership and borrowing without the details of\nlifetime analysis. This semantics models a high-level understanding of\nownership and as a result is close to source-level Rust (but with full type\nannotations) which differs from the recent RustBelt effort that essentially\nmodels MIR, a CPS-style IR used in the Rust compiler. Further, while RustBelt\naims to verify the safety of unsafe code in Rust's standard library, we model\nstandard library APIs as primitives, which is sufficient to reason about their\nbehavior. This yields a simpler model of Rust and its type system that we think\nresearchers will find easier to use as a starting point for investigating Rust\nextensions. Unlike RustBelt, we aim to prove type soundness using progress and\npreservation instead of a Kripke logical relation. Finally, our semantics is a\nfamily of languages of increasing expressive power, where subsequent levels\nhave features that are impossible to define in previous levels. Following\nFelleisen, expressive power is defined in terms of observational equivalence.\nSeparating the language into different levels of expressive power should\nprovide a framework for future work on Rust verification and compiler\noptimization.\n",
"title": "Rust Distilled: An Expressive Tower of Languages"
}
| null | null | null | null | true | null |
16662
| null |
Default
| null | null |
null |
{
"abstract": " Game Theory (GT) has been used with significant success to formulate, and\neither design or optimize, the operation of many representative communications\nand networking scenarios. The games in these scenarios involve, as usual,\ndiverse players with conflicting goals. This paper primarily surveys the\nliterature that has applied theoretical games to wireless networks, emphasizing\nuse cases of upcoming Multi-Access Edge Computing (MEC). MEC is relatively new\nand offers cloud services at the network periphery, aiming to reduce service\nlatency backhaul load, and enhance relevant operational aspects such as Quality\nof Experience or security. Our presentation of GT is focused on the major\nchallenges imposed by MEC services over the wireless resources. The survey is\ndivided into classical and evolutionary games. Then, our discussion proceeds to\nmore specific aspects which have a considerable impact on the game usefulness,\nnamely: rational vs. evolving strategies, cooperation among players, available\ngame information, the way the game is played (single turn, repeated), the game\nmodel evaluation, and how the model results can be applied for both optimizing\nresource-constrained resources and balancing diverse trade-offs in real edge\nnetworking scenarios. Finally, we reflect on lessons learned, highlighting\nfuture trends and research directions for applying theoretical model games in\nupcoming MEC services, considering both network design issues and usage\nscenarios.\n",
"title": "Game Theory for Multi-Access Edge Computing: Survey, Use Cases, and Future Trends"
}
| null | null | null | null | true | null |
16663
| null |
Default
| null | null |
null |
{
"abstract": " The general theoretical description of the influence of oscillating\nhorizontal magnetic and quasimagnetic fields on the spin evolution in storage\nrings is presented. Previous results are generalized to the case when both of\nthe horizontal components of the oscillating field are nonzero and the vector\nof this field circumscribes an ellipse. General equations describing a behavior\nof all components of the polarization vector are derived and the case of an\narbitrary initial polarization is considered. The derivation is fulfilled in\nthe case when the oscillation frequency is nonresonant. The general spin\nevolution in storage rings conditioned by vertical betatron oscillations is\ncalculated as an example.\n",
"title": "General description of spin motion in storage rings in presence of oscillating horizontal fields"
}
| null | null | null | null | true | null |
16664
| null |
Default
| null | null |
null |
{
"abstract": " Robots performing manipulation tasks must operate under uncertainty about\nboth their pose and the dynamics of the system. In order to remain robust to\nmodeling error and shifts in payload dynamics, agents must simultaneously\nperform estimation and control tasks. However, the optimal estimation actions\nare often not the optimal actions for accomplishing the control tasks, and thus\nagents trade between exploration and exploitation. This work frames the problem\nas a Bayes-adaptive Markov decision process and solves it online using Monte\nCarlo tree search and an extended Kalman filter to handle Gaussian process\nnoise and parameter uncertainty in a continuous space. MCTS selects control\nactions to reduce model uncertainty and reach the goal state nearly optimally.\nCertainty equivalent model predictive control is used as a benchmark to compare\nperformance in simulations with varying process noise and parameter\nuncertainty.\n",
"title": "Simultaneous active parameter estimation and control using sampling-based Bayesian reinforcement learning"
}
| null | null | null | null | true | null |
16665
| null |
Default
| null | null |
null |
{
"abstract": " In Mexico, 25 per cent of the urban population now lives in informal\nsettlements with varying degree of depravity. Although some informal\nneighbourhoods have contributed to the upward mobility of the inhabitants, the\nmajority still lack basic services. Mexico City and the conurbation around it,\nform a mega city of 21 million people that has been growing in a manner\nqualified as \"highly unproductive, (that) deepens inequality, raises pollution\nlevels\" and contains the largest slum in the world, Neza-Chalco-Izta. Urban\nreforms are now aiming to better the conditions in these slums and therefore it\nis very important to have reliable measurement tools to assess the changes that\nare undergoing. In this paper, we use exploratory factor analysis to define an\nindex of depravity in Mexico City, namely the Slum Severity Index (SSI), based\non the UN-HABITATs definition of a slum. We apply this novel approach to the\nCensus survey of Mexico and measure the housing deprivation levels types from\n1990 - 2010. The analysis highlights high variability in housing conditions\nwithin Mexico City. We find that the SSI decreased significantly between 1990 -\n2000 due to several policy reforms, but increased between 2000 - 2010. We also\nshow correlations of the SSI with other social factors such as education,\nhealth and migration. We present a validation of the SSI using Grey Level\nCo-occurrence Matrix (GLCM) features extracted from Very-High Resolution (VHR)\nremote-sensed satellite images. Finally, we show that the SSI can present a\ncardinally meaningful assessment of the extent of the difference in depravity\nas compared to a similar index defined by CONEVAL, a government institution\nthat studies poverty in Mexico.\n",
"title": "An exploratory factor analysis model for slum severity index in Mexico City"
}
| null | null | null | null | true | null |
16666
| null |
Default
| null | null |
null |
{
"abstract": " Based on the work of Schoen-Yau, we derive an estimate of the first\neigenvalue of a Schrödinger Operator (the Jaocbi operator of minimal surfaces\nin flat 3-spaces) on surfaces.\n",
"title": "An Estimate of the First Eigenvalue of a Schrödinger Operator on Closed Surfaces"
}
| null | null |
[
"Mathematics"
] | null | true | null |
16667
| null |
Validated
| null | null |
null |
{
"abstract": " We present ease.ml, a declarative machine learning service platform we built\nto support more than ten research groups outside the computer science\ndepartments at ETH Zurich for their machine learning needs. With ease.ml, a\nuser defines the high-level schema of a machine learning application and\nsubmits the task via a Web interface. The system automatically deals with the\nrest, such as model selection and data movement. In this paper, we describe the\nease.ml architecture and focus on a novel technical problem introduced by\nease.ml regarding resource allocation. We ask, as a \"service provider\" that\nmanages a shared cluster of machines among all our users running machine\nlearning workloads, what is the resource allocation strategy that maximizes the\nglobal satisfaction of all our users?\nResource allocation is a critical yet subtle issue in this multi-tenant\nscenario, as we have to balance between efficiency and fairness. We first\nformalize the problem that we call multi-tenant model selection, aiming for\nminimizing the total regret of all users running automatic model selection\ntasks. We then develop a novel algorithm that combines multi-armed bandits with\nBayesian optimization and prove a regret bound under the multi-tenant setting.\nFinally, we report our evaluation of ease.ml on synthetic data and on one\nservice we are providing to our users, namely, image classification with deep\nneural networks. Our experimental evaluation results show that our proposed\nsolution can be up to 9.8x faster in achieving the same global quality for all\nusers as the two popular heuristics used by our users before ease.ml.\n",
"title": "Ease.ml: Towards Multi-tenant Resource Sharing for Machine Learning Workloads"
}
| null | null | null | null | true | null |
16668
| null |
Default
| null | null |
null |
{
"abstract": " Encrypting data before sending it to the cloud protects it against hackers\nand malicious insiders, but requires the cloud to compute on encrypted data.\nTrusted (hardware) modules, e.g., secure enclaves like Intel's SGX, can very\nefficiently run entire programs in encrypted memory. However, it already has\nbeen demonstrated that software vulnerabilities give an attacker ample\nopportunity to insert arbitrary code into the program. This code can then\nmodify the data flow of the program and leak any secret in the program to an\nobserver in the cloud via SGX side-channels. Since any larger program is rife\nwith software vulnerabilities, it is not a good idea to outsource entire\nprograms to an SGX enclave. A secure alternative with a small trusted code base\nwould be fully homomorphic encryption (FHE) -- the holy grail of encrypted\ncomputation. However, due to its high computational complexity it is unlikely\nto be adopted in the near future. As a result researchers have made several\nproposals for transforming programs to perform encrypted computations on less\npowerful encryption schemes. Yet, current approaches fail on programs that make\ncontrol-flow decisions based on encrypted data. In this paper, we introduce the\nconcept of data flow authentication (DFAuth). DFAuth prevents an adversary from\narbitrarily deviating from the data flow of a program. Hence, an attacker\ncannot perform an attack as outlined before on SGX. This enables that all\nprograms, even those including operations on control-flow decision variables,\ncan be computed on encrypted data. We implemented DFAuth using a novel\nauthenticated homomorphic encryption scheme, a Java bytecode-to-bytecode\ncompiler producing fully executable programs, and SGX enclaves. A transformed\nneural network that performs machine learning on sensitive medical data can be\nevaluated on encrypted inputs and encrypted weights in 0.86 seconds.\n",
"title": "Computation on Encrypted Data using Data Flow Authentication"
}
| null | null | null | null | true | null |
16669
| null |
Default
| null | null |
null |
{
"abstract": " Let $I=(c,d)$, $c < 0 < d$, $Q\\in C^1: I\\rightarrow[0,\\infty)$ be a function\nwith given regularity behavior on $I$. Write $w:=\\exp(-Q)$ on $I$ and assume\nthat $\\int_I x^nw^2(x)dx<\\infty$ for all $n=0,1,2,\\ldots$. For $x\\in I$, we\nconsider the problem of the analytic and numerical approximation of the Cauchy\nprincipal value integral: \\begin{equation*} I[f;x]:=\\lim_{\\varepsilon \\to 0+}\n\\left( \\int_{c}^{x-\\varepsilon} w^2(t)\\frac{f(t)}{t-x}dt+\n\\int_{x+\\varepsilon}^{d} w^2(t)\\frac{f(t)}{t-x}dt. \\right) \\end{equation*} for\na class of functions $f: I\\rightarrow \\mathbb{R^+}$ for which $I[f;x]$ is\nfinite. In [1-4], the first two authors studied this problem and some of its\napplications for even exponential weights $w$ on $(-\\infty,\\infty)$ of smooth\npolynomial decay at $\\pm \\infty$ and given regularity.\n",
"title": "Analytic and Numerical Analysis of Singular Cauchy integrals with exponential-type weights"
}
| null | null | null | null | true | null |
16670
| null |
Default
| null | null |
null |
{
"abstract": " We demonstrate a close connection between observed field-induced\nantiferromagnetic (AFM) order and quantum critical fluctuation (QCF) in the\nZn7%-doped heavy-fermion superconductor CeCoIn5. Magnetization, specific heat,\nand electrical resistivity at low temperatures all show the presence of new\nfield-induced AFM order under the magnetic field B of 5-10 T, whose order\nparameter is clearly distinguished from the low-field AFM phase observed for B\n< 5 T and the superconducting phase for B < 3 T. The 4f electronic specific\nheat divided by the temperature, C_e/T, exhibits -lnT dependence at B~10 T (=\nB_0), and furthermore, the C_e/T data for B >= B_0 are well scaled by the\nlogarithmic function of B and T: ln[(B-B_0)/T^{2.7}]. These features are quite\nsimilar to the scaling behavior found in pure CeCoIn5, strongly suggesting that\nthe field-induced QCF in pure CeCoIn5 originates from the hidden AFM order\nparameter equivalent to high-field AFM order in Zn7%-doped CeCoIn5.\n",
"title": "Observation of a new field-induced phase transition and its concomitant quantum critical fluctuations in CeCo(In$_{1-x}$Zn$_x$)$_5$"
}
| null | null |
[
"Physics"
] | null | true | null |
16671
| null |
Validated
| null | null |
null |
{
"abstract": " We report on the realization of a transversely loaded two-dimensional\nmagneto-optical trap serving as a source for cold strontium atoms. We analyze\nthe dependence of the source's properties on various parameters, in particular\nthe intensity of a pushing beam accelerating the atoms out of the source. An\natomic flux exceeding $10^9\\,\\mathrm{atoms/s}$ at a rather moderate oven\ntemperature of $500\\,^\\circ\\mathrm{C}$ is achieved. The longitudinal velocity\nof the atomic beam can be tuned over several tens of m/s by adjusting the power\nof the pushing laser beam. The beam divergence is around $60$ mrad, determined\nby the transverse velocity distribution of the cold atoms. The slow atom source\nis used to load a three-dimensional magneto-optical trap realizing loading\nrates up to $10^9\\,\\mathrm{atoms/s}$ without indication of saturation of the\nloading rate for increasing oven temperature. The compact setup avoids\nundesired effects found in alternative sources like, e.g., Zeeman slowers, such\nas vacuum contamination and black-body radiation due to the hot strontium oven.\n",
"title": "Two-dimensional magneto-optical trap as a source for cold strontium atoms"
}
| null | null | null | null | true | null |
16672
| null |
Default
| null | null |
null |
{
"abstract": " We present experimental measurements of the steady-state ion number in a\nlinear Paul trap (LPT) as a function of the ion-loading rate. These\nmeasurements, taken with (a) constant Paul trap stability parameter $q$, (b)\nconstant radio-frequency (rf) amplitude, or (c) constant rf frequency, show\nnonlinear behavior. At the loading rates achieved in this experiment, a plot of\nthe steady-state ion number as a function of loading rate has two regions: a\nmonotonic rise (region I) followed by a plateau (region II). Also described are\nsimulations and analytical theory which match the experimental results. Region\nI is caused by rf heating and is fundamentally due to the time dependence of\nthe rf Paul-trap forces. We show that the time-independent pseudopotential,\nfrequently used in the analytical investigation of trapping experiments, cannot\nexplain region I, but explains the plateau in region II and can be used to\npredict the steady-state ion number in that region. An important feature of our\nexperimental LPT is the existence of a radial cut-off $\\hat R_{\\rm cut}$ that\nlimits the ion capacity of our LPT and features prominently in the analytical\nand numerical analysis of our LPT-loading results. We explain the dynamical\norigin of $\\hat R_{\\rm cut}$ and relate it to the chaos border of the fractal\nof non-escaping trajectories in our LPT. We also present an improved model of\nLPT ion-loading as a function of time.\n",
"title": "Loading a linear Paul trap to saturation from a magneto-optical trap"
}
| null | null | null | null | true | null |
16673
| null |
Default
| null | null |
null |
{
"abstract": " Summary\n1. Infectious disease outbreaks in plants threaten ecosystems, agricultural\ncrops and food trade. Currently, several fungal diseases are affecting forests\nworldwide, posing a major risk to tree species, habitats and consequently\necosystem decay. Prediction and control of disease spread are difficult, mainly\ndue to the complexity of the interaction between individual components\ninvolved.\n2. In this work, we introduce a lattice-based epidemic model coupled with a\nstochastic process that mimics, in a very simplified way, the interaction\nbetween the hosts and pathogen. We studied the disease spread by measuring the\npropagation velocity of the pathogen on the susceptible hosts. Quantitative\nresults indicate the occurrence of a critical transition between two stable\nphases: local confinement and an extended epiphytotic outbreak that depends on\nthe density of the susceptible individuals.\n3. Quantitative predictions of epiphytotics are performed using the framework\nearly-warning indicators for impending regime shifts, widely applied on\ndynamical systems. These signals forecast successfully the outcome of the\ncritical shift between the two stable phases before the system enters the\nepiphytotic regime.\n4. Synthesis: Our study demonstrates that early-warning indicators could be\nuseful for the prediction of forest disease epidemics through mathematical and\ncomputational models suited to more specific pathogen-host-environmental\ninteractions.\n",
"title": "Early warning signals in plant disease outbreaks"
}
| null | null |
[
"Quantitative Biology"
] | null | true | null |
16674
| null |
Validated
| null | null |
null |
{
"abstract": " We investigated a way to predict the gender of a name using character-level\nLong-Short Term Memory (char-LSTM). We compared our method with some\nconventional machine learning methods, namely Naive Bayes, logistic regression,\nand XGBoost with n-grams as the features. We evaluated the models on a dataset\nconsisting of the names of Indonesian people. It is not common to use a family\nname as the surname in Indonesian culture, except in some ethnicities.\nTherefore, we inferred the gender from both full names and first names. The\nresults show that we can achieve 92.25% accuracy from full names, while using\nfirst names only yields 90.65% accuracy. These results are better than the ones\nfrom applying the classical machine learning algorithms to n-grams.\n",
"title": "Predicting the Gender of Indonesian Names"
}
| null | null |
[
"Computer Science"
] | null | true | null |
16675
| null |
Validated
| null | null |
null |
{
"abstract": " Information technology (IT) has been used widely in many aspects of our daily\nlife. After discuss politics related aspects for some articles. In this article\nauthor would like to discuss social media for students learning environment.\nSocial media as a leading application on the internet has changed many aspects\nof life become more globalized. This article discusses the use of social media\nto support learning activities for students in the faculty of computer science.\nThe author uses Facebook and WordPress as an alternative to electronic\nlearning: 1) online attendance tool, 2) media storage and dissemination of\ncourse materials, 3) event scheduling for the lectures. Social media succeed to\nchange the way of modern learning styles and environment. The results of this\nstudy are some learning activities such as : 1) Preparation, 2) Weekly meeting\nactivities, 3) Course Page, 4) Social Media as Online Attendance Tool, 5)\nSocial Media as Learning Repository and Dissemination, and 6) Social Media as\nOnline Event Scheduling.\n",
"title": "Exploring Students Blended Learning Through Social Media"
}
| null | null | null | null | true | null |
16676
| null |
Default
| null | null |
null |
{
"abstract": " In this paper we consider an online recommendation setting, where a platform\nrecommends a sequence of items to its users at every time period. The users\nrespond by selecting one of the items recommended or abandon the platform due\nto fatigue from seeing less useful items. Assuming a parametric stochastic\nmodel of user behavior, which captures positional effects of these items as\nwell as the abandoning behavior of users, the platform's goal is to recommend\nsequences of items that are competitive to the single best sequence of items in\nhindsight, without knowing the true user model a priori. Naively applying a\nstochastic bandit algorithm in this setting leads to an exponential dependence\non the number of items. We propose a new Thompson sampling based algorithm with\nexpected regret that is polynomial in the number of items in this combinatorial\nsetting, and performs extremely well in practice. We also show a contextual\nversion of our solution.\n",
"title": "Thompson Sampling for a Fatigue-aware Online Recommendation System"
}
| null | null | null | null | true | null |
16677
| null |
Default
| null | null |
null |
{
"abstract": " In this paper we present and expand upon procedures for obtaining large d\ndigit prime number to an arbitrary probability. We use a layered approach. The\nfirst step is to limit the pool of random number to exclude numbers that are\nobviously composite. We first remove any number ending in 1,3,7 or 9. We then\nexclude numbers whose digital root is not 3, 6, or 9. This sharply reduces the\nprobability of the random number being composite. We then use the Prime Number\nTheorem to find the probability that the selected number n is prime and use\nprimality tests to increase the probability to an arbitrarily high degree that\nn is prime. We apply primality tests including Euler's test based on Fermat\nLittle theorem and the Miller-Rabin test. We computed these conditional\nprobabilities and implemented it using the GNU GMP library.\n",
"title": "Finding Large Primes"
}
| null | null | null | null | true | null |
16678
| null |
Default
| null | null |
null |
{
"abstract": " We consider optimal designs for general multinomial logistic models, which\ncover baseline-category, cumulative, adjacent-categories, and\ncontinuation-ratio logit models, with proportional odds, non-proportional odds,\nor partial proportional odds assumption. We derive the corresponding Fisher\ninformation matrices in three different forms to facilitate their calculations,\ndetermine the conditions for their positive definiteness, and search for\noptimal designs. We conclude that, unlike the designs for binary responses, a\nfeasible design for a multinomial logistic model may contain less experimental\nsettings than parameters, which is of practical significance. We also conclude\nthat even for a minimally supported design, a uniform allocation, which is\ntypically used in practice, is not optimal in general for a multinomial\nlogistic model. We develop efficient algorithms for searching D-optimal\ndesigns. Using examples based on real experiments, we show that the efficiency\nof an experiment can be significantly improved if our designs are adopted.\n",
"title": "D-optimal Designs for Multinomial Logistic Models"
}
| null | null |
[
"Mathematics",
"Statistics"
] | null | true | null |
16679
| null |
Validated
| null | null |
null |
{
"abstract": " Learning to optimize - the idea that we can learn from data algorithms that\noptimize a numerical criterion - has recently been at the heart of a growing\nnumber of research efforts. One of the most challenging issues within this\napproach is to learn a policy that is able to optimize over classes of\nfunctions that are fairly different from the ones that it was trained on. We\npropose a novel way of framing learning to optimize as a problem of learning a\ngood navigation policy on a partially observable loss surface. To this end, we\ndevelop Rover Descent, a solution that allows us to learn a fairly broad\noptimization policy from training on a small set of prototypical\ntwo-dimensional surfaces that encompasses the classically hard cases such as\nvalleys, plateaus, cliffs and saddles and by using strictly zero-order\ninformation. We show that, without having access to gradient or curvature\ninformation, we achieve state-of-the-art convergence speed on optimization\nproblems not presented at training time such as the Rosenbrock function and\nother hard cases in two dimensions. We extend our framework to optimize over\nhigh dimensional landscapes, while still handling only two-dimensional local\nlandscape information and show good preliminary results.\n",
"title": "Rover Descent: Learning to optimize by learning to navigate on prototypical loss surfaces"
}
| null | null | null | null | true | null |
16680
| null |
Default
| null | null |
null |
{
"abstract": " In the well known logistic map, the parameter of interest is weighted by a\ncoefficient that decreases linearly when this parameter increases. Since such a\nlinear decrease forms a specific case, we consider the more general case where\nthis coefficient decreases nonlinearly as in a hyperbolic tangent relaxation of\na system toward equilibrium. We show that, in this latter case, the asymptotic\nvalues obtained via iteration of the logistic map are considerably modified. We\ndemonstrate that both the steepness of the nonlinear decrease as well as its\nupper and lower boundaries significantly alter the bifurcation diagram. New\nperiod doubling features and transitions to chaos appear, possibly leading to\nregimes with small periods. Computations with a variety of parameter values\nshow that the logistic map can be significantly reordered in the case of a\nnonlinear growth rate.\n",
"title": "Reordering of the Logistic Map with a Nonlinear Growth Rate"
}
| null | null | null | null | true | null |
16681
| null |
Default
| null | null |
null |
{
"abstract": " Advanced brain imaging techniques make it possible to measure individuals'\nstructural connectomes in large cohort studies non-invasively. The structural\nconnectome is initially shaped by genetics and subsequently refined by the\nenvironment. It is extremely interesting to study relationships between\nstructural connectomes and environment factors or human traits, such as\nsubstance use and cognition. Due to limitations in structural connectome\nrecovery, previous studies largely focus on functional connectomes. Questions\nremain about how well structural connectomes can explain variance in different\nhuman traits. Using a state-of-the-art structural connectome processing\npipeline and a novel dimensionality reduction technique applied to data from\nthe Human Connectome Project (HCP), we show strong relationships between\nstructural connectomes and various human traits. Our dimensionality reduction\napproach uses a tensor characterization of the connectome and relies on a\ngeneralization of principal components analysis. We analyze over 1100 scans for\n1076 subjects from the HCP and the Sherbrooke test-retest data set, as well as\n$175$ human traits that measure domains including cognition, substance use,\nmotor, sensory and emotion. We find that structural connectomes are associated\nwith many traits. Specifically, fluid intelligence, language comprehension, and\nmotor skills are associated with increased cortical-cortical brain structural\nconnectivity, while the use of alcohol, tobacco, and marijuana are associated\nwith decreased cortical-cortical connectivity.\n",
"title": "Tensor network factorizations: Relationships between brain structural connectomes and traits"
}
| null | null | null | null | true | null |
16682
| null |
Default
| null | null |
null |
{
"abstract": " We present a deep neural network for a model-free prediction of a chaotic\ndynamical system from noisy observations. The proposed deep learning model aims\nto predict the conditional probability distribution of a state variable. The\nLong Short-Term Memory network (LSTM) is employed to model the nonlinear\ndynamics and a softmax layer is used to approximate a probability distribution.\nThe LSTM model is trained by minimizing a regularized cross-entropy function.\nThe LSTM model is validated against delay-time chaotic dynamical systems,\nMackey-Glass and Ikeda equations. It is shown that the present LSTM makes a\ngood prediction of the nonlinear dynamics by effectively filtering out the\nnoise. It is found that the prediction uncertainty of a multiple-step forecast\nof the LSTM model is not a monotonic function of time; the predicted standard\ndeviation may increase or decrease dynamically in time.\n",
"title": "Model-free prediction of noisy chaotic time series by deep learning"
}
| null | null |
[
"Computer Science",
"Physics"
] | null | true | null |
16683
| null |
Validated
| null | null |
null |
{
"abstract": " We introduce an arbitrage-free framework for robust valuation adjustments. An\ninvestor trades a credit default swap portfolio with a risky counterparty, and\nhedges credit risk by taking a position in the counterparty bond. The investor\ndoes not know the expected rate of return of the counterparty bond, but he is\nconfident that it lies within an uncertainty interval. We derive both upper and\nlower bounds for the XVA process of the portfolio, and show that these bounds\nmay be recovered as solutions of nonlinear ordinary differential equations. The\npresence of collateralization and closeout payoffs leads to fundamental\ndifferences with respect to classical credit risk valuation. The value of the\nsuper-replicating portfolio cannot be directly obtained by plugging one of the\nextremes of the uncertainty interval in the valuation equation, but rather\ndepends on the relation between the XVA replicating portfolio and the close-out\nvalue throughout the life of the transaction.\n",
"title": "Robust XVA"
}
| null | null | null | null | true | null |
16684
| null |
Default
| null | null |
null |
{
"abstract": " We apply the method of nonlinear steepest descent to compute the long-time\nasymptotics of the Toda lattice with steplike initial data corresponding to a\nrarefaction wave.\n",
"title": "Rarefaction Waves for the Toda Equation via Nonlinear Steepest Descent"
}
| null | null |
[
"Physics",
"Mathematics"
] | null | true | null |
16685
| null |
Validated
| null | null |
null |
{
"abstract": " In this paper, we consider coding of short data frames (192 bits) by IRA\ncodes. A new interleaver for the IRA codes based on a Gruenbaum graph is\nproposed. The difference of the proposed algorithm from known methods consists\nin the following: permutation is performed by using a match smaller interleaver\nwhich is derived from the Gruenbaum graph by finding in this graph a\nHamiltonian path, enumerating the passed vertices in ascending order and\npassing them again in the permuted order through the edges which are not\nincluded in the Hamiltonian path. For the IRA code the obtained interleaver\nprovides 0.7-0.8 db gain over a convolutional code decoded by Viterbi\nalgorithm.\n",
"title": "IRA codes derived from Gruenbaum graph"
}
| null | null | null | null | true | null |
16686
| null |
Default
| null | null |
null |
{
"abstract": " We report the three main ingredients to calculate three- and four-electron\nintegrals over Gaussian basis functions involving Gaussian geminal operators:\nfundamental integrals, upper bounds, and recurrence relations. In particular,\nwe consider the three- and four-electron integrals that may arise in\nexplicitly-correlated F12 methods. A straightforward method to obtain the\nfundamental integrals is given. We derive vertical, transfer and horizontal\nrecurrence relations to build up angular momentum over the centers. Strong,\nsimple and scaling-consistent upper bounds are also reported. This latest\ningredient allows to compute only the $\\order{N^2}$ significant three- and\nfour-electron integrals, avoiding the computation of the very large number of\nnegligible integrals.\n",
"title": "Three- and four-electron integrals involving Gaussian geminals: fundamental integrals, upper bounds and recurrence relations"
}
| null | null | null | null | true | null |
16687
| null |
Default
| null | null |
null |
{
"abstract": " We present HARP, a novel method for learning low dimensional embeddings of a\ngraph's nodes which preserves higher-order structural features. Our proposed\nmethod achieves this by compressing the input graph prior to embedding it,\neffectively avoiding troublesome embedding configurations (i.e. local minima)\nwhich can pose problems to non-convex optimization. HARP works by finding a\nsmaller graph which approximates the global structure of its input. This\nsimplified graph is used to learn a set of initial representations, which serve\nas good initializations for learning representations in the original, detailed\ngraph. We inductively extend this idea, by decomposing a graph in a series of\nlevels, and then embed the hierarchy of graphs from the coarsest one to the\noriginal graph. HARP is a general meta-strategy to improve all of the\nstate-of-the-art neural algorithms for embedding graphs, including DeepWalk,\nLINE, and Node2vec. Indeed, we demonstrate that applying HARP's hierarchical\nparadigm yields improved implementations for all three of these methods, as\nevaluated on both classification tasks on real-world graphs such as DBLP,\nBlogCatalog, CiteSeer, and Arxiv, where we achieve a performance gain over the\noriginal implementations by up to 14% Macro F1.\n",
"title": "HARP: Hierarchical Representation Learning for Networks"
}
| null | null | null | null | true | null |
16688
| null |
Default
| null | null |
null |
{
"abstract": " When a signal is recorded in an enclosed room, it typically gets affected by\nreverberation. This degradation represents a problem when dealing with audio\nsignals, particularly in the field of speech signal processing, such as\nautomatic speech recognition. Although there are some approaches to deal with\nthis issue that are quite satisfactory under certain conditions, constructing a\nmethod that works well in a general context still poses a significant\nchallenge. In this article, we propose a method based on convolutive\nnonnegative matrix factorization that mixes two penalizers in order to impose\ncertain characteristics over the time-frequency components of the restored\nsignal and the reverberant components. An algorithm for implementing the method\nis described and tested. Comparisons of the results against those obtained with\nstate of the art methods are presented, showing significant improvement.\n",
"title": "Mixed penalization in convolutive nonnegative matrix factorization for blind speech dereverberation"
}
| null | null | null | null | true | null |
16689
| null |
Default
| null | null |
null |
{
"abstract": " The current generation of radio and millimeter telescopes, particularly the\nAtacama Large Millimeter Array (ALMA), offers enormous advances in observing\ncapabilities. While these advances represent an unprecedented opportunity to\nadvance scientific understanding, the increased complexity in the spatial and\nspectral structure of even a single spectral line is hard to interpret. The\ncomplexity present in current ALMA data cubes therefore challenges not only the\nexisting tools for fundamental analysis of these datasets, but also users'\nability to explore and visualize their data. We have performed a feasibility\nstudy for applying forms of topological data analysis and visualization never\nbefore tested by the ALMA community. Through contour tree-based data analysis,\nwe seek to improve upon existing data cube analysis and visualization\nworkflows, in the forms of improved accuracy and speed in extracting features.\nIn this paper, we review our design process in building effective analysis and\nvisualization capabilities for the astrophysicist users. We summarize effective\ndesign practices, in particular, we identify domain-specific needs of\nsimplicity, integrability and reproducibility, in order to best target and\nservice the large astrophysics community.\n",
"title": "Using Contour Trees in the Analysis and Visualization of Radio Astronomy Data Cubes"
}
| null | null | null | null | true | null |
16690
| null |
Default
| null | null |
null |
{
"abstract": " This is the first paper that estimates the price determinants of BitCoin in a\nGeneralised Autoregressive Conditional Heteroscedasticity framework using high\nfrequency data. Derived from a theoretical model, we estimate BitCoin\ntransaction demand and speculative demand equations in a GARCH framework using\nhourly data for the period 2013-2018. In line with the theoretical model, our\nempirical results confirm that both the BitCoin transaction demand and\nspeculative demand have a statistically significant impact on the BitCoin price\nformation. The BitCoin price responds negatively to the BitCoin velocity,\nwhereas positive shocks to the BitCoin stock, interest rate and the size of the\nBitCoin economy exercise an upward pressure on the BitCoin price.\n",
"title": "The Price of BitCoin: GARCH Evidence from High Frequency Data"
}
| null | null | null | null | true | null |
16691
| null |
Default
| null | null |
null |
{
"abstract": " Kenmotsu's formula describes surfaces in Euclidean 3-space by their mean\ncurvature functions and Gauss maps. In Lorentzian 3-space,\nAkutagawa-Nishikawa's formula and Magid's formula are Kenmotsu-type formulas\nfor spacelike surfaces and for timelike surfaces, respectively. We apply them\nto a few problems concerning rotational or helicoidal surfaces with constant\nmean curvature. Before that, we show that the three formulas above can be\nwritten in a unified single equation.\n",
"title": "Application of a unified Kenmotsu-type formula for surfaces in Euclidean or Lorentzian three-space"
}
| null | null | null | null | true | null |
16692
| null |
Default
| null | null |
null |
{
"abstract": " In this paper, the structural controllability of the systems over F(z) is\nstudied using a new mathematical method-matroids. Firstly, a vector matroid is\ndefined over F(z). Secondly, the full rank conditions of [sI-A|B] are derived\nin terms of the concept related to matroid theory, such as rank, base and\nunion. Then the sufficient condition for the linear system and composite system\nover F(z) to be structurally controllable is obtained. Finally, this paper\ngives several examples to demonstrate that the married-theoretic approach is\nsimpler than other existing approaches.\n",
"title": "A Vector Matroid-Theoretic Approach in the Study of Structural Controllability Over F(z)"
}
| null | null | null | null | true | null |
16693
| null |
Default
| null | null |
null |
{
"abstract": " Strongly coupled quantum fluids are found in different forms, including\nultracold Fermi gases or tiny droplets of extremely hot Quark-Gluon Plasma.\nAlthough the systems differ in temperature by many orders of magnitude, they\nexhibit a similar almost inviscid fluid dynamical behavior. In this work, we\nsummarize some of the recent theoretical developments toward better\nunderstanding this property in cold Fermi gases at and near unitarity.\n",
"title": "From cold Fermi fluids to the hot QGP"
}
| null | null | null | null | true | null |
16694
| null |
Default
| null | null |
null |
{
"abstract": " In this paper we study the problem of hyperball (hypersphere) packings in\n$3$-dimensional hyperbolic space. We introduce a new definition of the\nnon-compact saturated ball packings and describe to each saturated hyperball\npacking, a new procedure to get a decomposition of 3-dimensional hyperbolic\nspace $\\HYP$ into truncated tetrahedra. Therefore, in order to get a density\nupper bound for hyperball packings, it is sufficient to determine the density\nupper bound of hyperball packings in truncated simplices.\n",
"title": "Decomposition method related to saturated hyperball packings"
}
| null | null | null | null | true | null |
16695
| null |
Default
| null | null |
null |
{
"abstract": " From critical infrastructure, to physiology and the human brain, complex\nsystems rarely occur in isolation. Instead, the functioning of nodes in one\nsystem often promotes or suppresses the functioning of nodes in another.\nDespite advances in structural interdependence, modeling interdependence and\nother interactions between dynamic systems has proven elusive. Here we define a\nbroadly applicable dynamic dependency link and develop a general framework for\ninterdependent and competitive interactions between general dynamic systems. We\napply our framework to studying interdependent and competitive synchronization\nin multi-layer oscillator networks and cooperative/competitive contagions in an\nepidemic model. Using a mean-field theory which we verify numerically, we find\nexplosive transitions and rich behavior which is absent in percolation models\nincluding hysteresis, multi-stability and chaos. The framework presented here\nprovides a powerful new way to model and understand many of the interacting\ncomplex systems which surround us.\n",
"title": "Dynamic interdependence and competition in multilayer networks"
}
| null | null | null | null | true | null |
16696
| null |
Default
| null | null |
null |
{
"abstract": " L systems generalise context-free grammars by incorporating parallel\nrewriting, and generate languages such as EDT0L and ET0L that are strictly\ncontained in the class of indexed languages. In this paper we show that many of\nthe languages naturally appearing in group theory, and that were known to be\nindexed or context-sensitive, are in fact ET0L and in many cases EDT0L. For\ninstance, the language of primitives in the free group on two generators, the\nBridson-Gilman normal forms for the fundamental groups of 3-manifolds or\norbifolds, and the co-word problem of Grigorchuk's group can be generated by L\nsystems. To complement the result on primitives in free groups, we show that\nthe language of primitives, and primitive sets, in free groups of rank higher\nthan two is context-sensitive. We also show the existence of EDT0L and ET0L\nlanguages of intermediate growth.\n",
"title": "Applications of L systems to group theory"
}
| null | null |
[
"Computer Science",
"Mathematics"
] | null | true | null |
16697
| null |
Validated
| null | null |
null |
{
"abstract": " One of the key aspects of the United States democracy is free and fair\nelections that allow for a peaceful transfer of power from one President to the\nnext. The 2016 US presidential election stands out due to suspected foreign\ninfluence before, during, and after the election. A significant portion of that\nsuspected influence was carried out via social media. In this paper, we look\nspecifically at 3,500 Facebook ads allegedly purchased by the Russian\ngovernment. These ads were released on May 10, 2018 by the US Congress House\nIntelligence Committee. We analyzed the ads using natural language processing\ntechniques to determine textual and semantic features associated with the most\neffective ones. We clustered the ads over time into the various campaigns and\nthe labeled parties associated with them. We also studied the effectiveness of\nAds on an individual, campaign and party basis. The most effective ads tend to\nhave less positive sentiment, focus on past events and are more specific and\npersonalized in nature. The more effective campaigns also show such similar\ncharacteristics. The campaigns' duration and promotion of the Ads suggest a\ndesire to sow division rather than sway the election.\n",
"title": "'Senator, We Sell Ads': Analysis of the 2016 Russian Facebook Ads Campaign"
}
| null | null |
[
"Computer Science"
] | null | true | null |
16698
| null |
Validated
| null | null |
null |
{
"abstract": " In this work, we study the $k$-means cost function. The (Euclidean) $k$-means\nproblem can be described as follows: given a dataset $X \\subseteq \\mathbb{R}^d$\nand a positive integer $k$, find a set of $k$ centers $C \\subseteq\n\\mathbb{R}^d$ such that $\\Phi(C, X) \\stackrel{def}{=} \\sum_{x \\in X} \\min_{c\n\\in C} ||x - c||^2$ is minimized. Let $\\Delta_k(X) \\stackrel{def}{=} \\min_{C\n\\subseteq \\mathbb{R}^d} \\Phi(C, X)$ denote the cost of the optimal $k$-means\nsolution. It is simple to observe that for any dataset $X$, $\\Delta_k(X)$\ndecreases as $k$ increases. We try to understand this behaviour more precisely.\nFor any dataset $X \\subseteq \\mathbb{R}^d$, integer $k \\geq 1$, and a small\nprecision parameter $\\varepsilon > 0$, let $\\mathcal{L}_{X}^{k, \\varepsilon}$\ndenote the smallest integer such that $\\Delta_{\\mathcal{L}_{X}^{k,\n\\varepsilon}}(X) \\leq \\varepsilon \\cdot \\Delta_{k}(X)$. We show upper and lower\nbounds on this quantity. Our techniques generalize for the metric $k$-median\nproblem in arbitrary metrics and we give bounds in terms of the doubling\ndimension of the metric. Finally, we observe that for any dataset $X$, we can\ncompute a set $S$ of size $O \\left(\\mathcal{L}_{X}^{k, \\frac{\\varepsilon}{c}}\n\\right)$ such that $\\Delta_{S}(X) \\leq \\varepsilon \\cdot \\Delta_k(X)$ using the\n$D^2$-sampling algorithm which is also known as the $k$-means++ seeding\nprocedure. In the previous statement, $c$ is some fixed constant. We also\ndiscuss some applications of our bounds.\n",
"title": "On the k-Means/Median Cost Function"
}
| null | null | null | null | true | null |
16699
| null |
Default
| null | null |
null |
{
"abstract": " The Internet of things (IoT) is revolutionizing the management and control of\nautomated systems leading to a paradigm shift in areas such as smart homes,\nsmart cities, health care, transportation, etc. The IoT technology is also\nenvisioned to play an important role in improving the effectiveness of military\noperations in battlefields. The interconnection of combat equipment and other\nbattlefield resources for coordinated automated decisions is referred to as the\nInternet of battlefield things (IoBT). IoBT networks are significantly\ndifferent from traditional IoT networks due to the battlefield specific\nchallenges such as the absence of communication infrastructure, and the\nsusceptibility of devices to cyber and physical attacks. The combat efficiency\nand coordinated decision-making in war scenarios depends highly on real-time\ndata collection, which in turn relies on the connectivity of the network and\nthe information dissemination in the presence of adversaries. This work aims to\nbuild the theoretical foundations of designing secure and reconfigurable IoBT\nnetworks. Leveraging the theories of stochastic geometry and mathematical\nepidemiology, we develop an integrated framework to study the communication of\nmission-critical data among different types of network devices and consequently\ndesign the network in a cost effective manner.\n",
"title": "Secure and Reconfigurable Network Design for Critical Information Dissemination in the Internet of Battlefield Things (IoBT)"
}
| null | null |
[
"Computer Science"
] | null | true | null |
16700
| null |
Validated
| null | null |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.