The delay between two signals is determined by obtaining zero crossings from each signal, and using each crossing to trigger the sampling of the other signal. Two samples are taken in response to each zero crossing, and the difference between those two samples is calculated. This difference is summed for each event and both signals to derive a value. The process is repeated for different delays between the first and second signals. The values are examined to determine the delay which corresponds to the greatest coincidence between the signals.

1. Field of the Invention
This invention relates to a method and apparatus for determining the relative time delay between two wideband signals, and is particularly but not exclusively applicable to estimating the line-of-bearing of a non-cooperative source of acoustic energy by determining the delay between two replicas of a wideband signal generated by the source and captured by a pair of collocated sensors.
2. Description of the Prior Art
There are many circumstances in which there is a need to detect and localize a noncooperative object of interest in some specified surveillance area. Such tasks can be performed by suitable active or passive sensors which can extract useful information by collaborative processing of signals reflected or emitted by that object.
In contrast to applications employing active sensors, such as radar or active sonar, in which the surveillance region of interest is illuminated by an interrogating energy waveform to obtain object-backscattered returns, passive sensors capture only object-generated signals (or object-influenced signals from separate sources). For example, the movement of people, vehicles, speedboats or vibrating machinery can all generate wideband acoustic signals, which can be exploited for object detection and localization.
As will be described in more detail below, an example in which object detection and localization is useful is that of security surveillance with a network of distributed acoustic sensors. When an object of interest, such as a vehicle, has been detected and localized, the estimated object position can be utilized by security cameras for aiming and zooming, in order to enhance the quality of recorded images. Such systems may be installed for monitoring purposes in industrial environments, e.g. to offer improved continuous surveillance of critical infrastructure, including power grids, power plants, gas and oil pipelines and water supply systems.
Another application is that of coastguard or littoral surveillance in which speedboats and other surface vessels of interest can be detected and localized by a network of floating buoys employing acoustic sensors.
In addition to the above surveillance and reconnaissance applications, in multimedia applications distributed microphone networks are capable of enhancing audio signals for improved intelligibility, and cuing for camera aiming.
Object-generated acoustic signals are classified as wideband signals since the ratio of their highest frequency component to lowest frequency component is relatively large. For example, for the audio range, 30 Hz to 15 kHz, the ratio is 500. In a case of motorized vehicles, dominant frequency components may range from 20 Hz to 2 kHz, resulting in a ratio of 100.
When the distance between an acoustic source and the sensors is large, the direction of wave propagation is approximately equal at each sensor (the far-field condition), and the propagating field consists of planar waves. Thus, for a far-field source, the angle of arrival (AOA) or direction-of-arrival (DOA) in the coordinate system of the sensors can be estimated directly from the relative delays of signals captured by sensors at different locations. Such relative delay is commonly referred to as the time-difference of arrival, or simply TDOA.
The angle of arrival (AOA) measurement restricts the location of the source along a line at the estimated angle of arrival (AOA). When multiple angle of arrival (AOA) measurements are made simultaneously by multiple spatially-separated sensors, a triangulation method may be used to determine the location of the source at the intersection of these lines-of-bearing.
FIG. 1 illustrates schematically a method of determining the angle of arrival θ from the time-difference of arrival (TDOA). As shown, a planar wave generated by a remote acoustic source reaches sensor SY first, and then sensor SX. From geometrical considerations, it follows that the angle of arrival (AOA) θ can be calculated from
  θ  =            arcsin                    (                  H          L                )              =          arcsin                    (                                            τ              0                                                  v              s                                L                )            where L is the distance between sensors, H represents the additional path length to sensor SX as referenced to sensor SY, τ0 is the time-difference of arrival (TDOA), and vs is the speed of sound.
For the purpose of angle of arrival (AOA) determination, a required time-difference of arrival (TDOA) estimate needs to be obtained from two signals, x(t) and y(t), captured by sensors SX and SY, respectively, wherex(t)=s(t)+nx(t) y(t)=s(t−τ0)+ny(t)where s(t) is an object-generated signal, τ0 denotes the time-difference of arrival (TDOA), and waveforms nx(t) and ny(t) represent background noise and other interference.
In the example shown in FIG. 1, the value τ0 is provided by a time-difference of arrival processor (TDOAP) crosscorrelating the wideband signals x(t) and y(t) captured by the sensors, i.e. by performing the operation
            R      xy                  (      τ      )        =            1      T                          ∫        0        T                                    x                                (                          t              -              τ                        )                                            y                                (            t            )                                            ⅆ          t                    where the integral is evaluated over the observation interval of duration T and for a range, −|τmax|<τ<|τmax|, of time-difference of arrival (TDOA) values of interest. The value of argument τ that maximizes the crosscorrelation function Rxy(τ) provides an estimate of an unknown time-difference of arrival (TDOA).
The value of the time-difference of arrival (TDOA) supplied by the time-difference of arrival processor (TDOAP) is converted into a corresponding angle of arrival (AOA) θ by an angle calculator (ACR), which may, for example, be implemented in the form of a suitable look-up table stored in a read-only memory.
Acoustic signals emitted by objects of interest, in addition to occupying a wide frequency range, also manifest a nonstationary and chaotic nature with identifiable intermittent transients. As a result, many conventional crosscorrelation techniques based, explicitly or implicitly, on the assumptions of signal stationarity and noise Gaussianity are only of limited practical use. Furthermore, most practical implementations have to deal with discrete-time samples, so that the optimization procedures and performance analyses carried out in the continuous-time framework cannot be fully applicable.
U.S. Pat. No. 6,539,320 discloses a robust method for determining the delay between a primary reference signal and its time-delayed replica. In the following, the disclosed method will be referred to as "crosslation", and a system implementing the method will be referred to as a "crosslator". The contents of U.S. Pat. No. 6,539,320 are incorporated herein by reference. A crosslation technique involves using events (such as zero crossings) from one signal to sample the other signal. The events occur at irregular intervals, and are preferably at least substantially aperiodic. The samples are combined to derive a value which represents the extent to which the sampling coincides with features of the second signal corresponding to the events. By repeating this process for different delays between the first and second signals, it is possible to find the delay which gives rise to the value representing the greatest coincidence of events, i.e. the delay between the two signals.
In the example described in the above disclosure, a nondeterministic signal x(t) is subjected to an unknown delay to produce a signal y(t), and a reference version of the signal x(t) is examined to determine the time instants at which its level crosses zero, either with a positive slope (an upcrossing) or with a negative slope (a downcrossing). The time instants of these crossing events are used to obtain respective segments of the signal y(t), the segments having a predetermined duration. The segments corresponding to zero upcrossings are all summed, and the segments corresponding to zero downcrossings are all subtracted from the resulting sum. A representation of such segment combination is then examined to locate a feature in the form of an S-shaped odd function. In the following, the S-shaped odd function will be referred to as the crosslation function.
The position within the representation of a zero-crossing in the centre of the crosslation function represents the amount of the mutual delay between the two signals being processed. FIG. 3 shows an example of an S-shaped crosslation function obtained experimentally by processing a random binary waveform and its time-delayed replica.
FIG. 2 shows one possible example of exploiting the concept of crosslation to construct a system capable of determining the delay between a nondeterministic signal x(t) and its time-delayed replica y(t). The signal y(t) is the sum of noise ny(t) and the signal x(t) attenuated by the factor of α and delayed by τ0, hencey(t)=αx(t−τ0)+ny(t)
As shown in FIG. 2, the signal y(t) is converted by a hard limiter HY into a corresponding binary bipolar waveform which is applied to the input of a tapped delay line TDY. The delay line TDY comprises a cascade of M identical unit-delay cells D1, D2, . . . , DJ, . . . , DM. Each cell provides a suitably delayed output signal and also its polarity-reversed replica supplied by inverter IR.
The parallel outputs of the tapped delay line TDY are connected through a bank of switches BS to M averaging or integrating units AVG that accumulate data supplied by the tapped delay line TDY. The switches, normally open, are closed when a suitable signal is applied to their common control input. The time interval during which the switches are closed should be sufficiently long so that each new incremental signal sample can be acquired with minimal loss.
The time instants, at which the switches are closed and new data supplied to the averaging units, are determined by a zero-crossing detector ZCD that detects the crossings of zero level of a binary waveform obtained from the reference signal x(t) processed by a hard limiter HX; the resulting binary waveform is then delayed by a constant-delay line CDX. The value of the constant delay is equal to or greater than the expected maximum value of time delay to be determined. It should be pointed out that the averaging units receive the incremental input values from the tapped delay line TDY in a non-uniform manner, at the time instants coinciding with zero crossings of the delayed reference signal x(t).
Each time a zero upcrossing occurs, there appears transiently at the inputs of the averaging units a replica of a respective segment of the binary waveform obtained from the signal y(t). Similarly, each time a zero downcrossing occurs, there appears transiently at the inputs of the averaging units a reversed-polarity replica of a respective segment of the binary waveform obtained from the signal y(t). The averaging units thus combine the two groups of these segments to produce a representation of a combined waveform, like that of FIG. 3.
The signals obtained at the outputs of the averaging units AVG are used by the data processor. The operations performed by the data processor are so defined and structured as to determine the location of the zero crossing situated between the two opposite-polarity main peaks exhibited by the resulting S-shaped crosslation function. The location of this zero crossing corresponds to the time delay between the signals x(t) and y(t). A set of suitable operations and their sequence can be constructed by anyone skilled in the art.
In order to simplify the structure of a crosslator system, instead of using both upcrossings and downcrossings, the reference version of a wideband non-deterministic signal x(t) can be examined to determine the time instants of zero upcrossings (or downcrossings) only. However, irrespective of the particular arrangement used, a crosslation-based technique always includes a step of determining the time instants at which a reference signal crosses a predetermined threshold. Those specific time instants are also referred to as significant events. In a hardware implementation of crosslation significant events define the time instants at which suitable trigger pulses are generated.
The crosslation techniques of U.S. Pat. No. 6,539,320 for time-delay determination are robust and particularly useful for processing non-Gaussian signals. However, crosslation in the disclosed form is not well suited to time-difference of arrival (TDOA) determination.
It would therefore be desirable to provide a method and an apparatus for determining time-difference of arrival (TDOA) in a more efficient way than that provided by the prior art techniques.
It would also be desirable to provide a time delay measurement technique which is less subject to noise, and more suited to detecting angle of arrival than prior art arrangements.

Determination of time-difference of arrival and angle of arrival


Provided in the present application are a one-time dynamic positioning authentication method, system and password changing method. The method comprises: an authentication server receives an authentication request from a client, generates a positioning factor string, and transmits generated information containing the positioning factor string and a structure of an all-element dynamic factor table to the client; the client receives the generated information, generates the all-element dynamic factor table, and maps the positioning factor string into the all-element dynamic factor table to acquire a dynamic graphical password inputted in accordance with a first positioning rule by a user and transmit to the authentication server; the authentication server receives the dynamic graphical password from the client, and if the first positioning rule corresponding to the parsed dynamic graphical password is consistent with a preset positioning rule, then the authentication is successful. The graphic passwords being visual and easy to remember, combined with the variability of one-time dynamic passwords, improves the overall convenience and security of an authentication system.

With the development of Internet technologies, an increasing number of websites are capable of providing Internet services. In order to obtain a service provided by a website, a user needs to log into a target service website by using a network terminal, and then obtain the service provided by the target service website by accessing the target service website. In order to ensure the security of network access, it is necessary for the target service website to authenticate the identity of the user on the network terminal side.
A common user identity authentication method conducts authentication in a manner of using a user name plus a password, in which the user name and the password will be fixed once confirmed, and are therefore extremely easy to be cracked. In order to improve the security of the fixed user name and password, a target service website providing a service has to pose various restrictions on the setting of the user name and password which are determined by the user through a network terminal, for example, the user name and password should be a combination of uppercase English letters, lowercase English letters, numerals and/or symbols. Consequently, not only is the user provided with a poor experience, but also the password is complex and difficult to remember. Even so, specific information of the user name and the password can still be easily obtained by simple means such as Trojan, phishing, and the like.
An improved user identity authentication method conducts authentication in other manners, such as dynamic password, token, and the like, which are popular user identity authentication methods at present, the main means of which including a dynamic password, a mobile token, a USB key, biometric authentication, etc. However, the implementation of these technologies depends upon hardware or third-party plug-in, as a result of which there still remains a security threat. For example, for a user identity authentication method using a mobile dynamic password, a short message service (SMS) message needs to be transmitted via a telecom operator, however, due to the attack means, such as illegal pseudo base station, Trojan, attacking service website platforms/radio towers, and the like, it is difficult to ensure the security of this authentication method; and for a user identity authentication method using a hardware token such as a mobile token, based on time error between network devices, user operation time, or other factors, an attacker can obtain token content in a short time and crack an account to steal user information, therefore, it is also difficult to ensure the security.

One-time dynamic positioning authentication method and system and password alteration method


A temporal-miss handler includes updating a data leaf in a tree-structured database of a communications processor with a plurality of threads. A search for the data leaf includes generating at least one search result for one of the plurality of threads. A sufficiency of a temporal separation, between updating the data leaf and searching for the data leaf, to retrieve the data leaf is determined. Each search result is cleared when the temporal separation is insufficient. A new search is performed when the temporal separation is insufficient.

A tree-structured database includes a multitude of interconnected nodes, beginning with a single root node. The root node connects to at least two other nodes, each of which may be connected to more nodes or may terminate with a connection to data leaves. The final interconnected node that connects to data leaves is referred to as a result node. A multi-threaded system will traverse the database from the root node to a data leaf with a variety of methods (e.g. in-order, post-order or level-order).
Multi-threaded systems must reliably retrieve data from a data leaf while the same data is being concurrently updated by another thread. The threads used to retrieve and to update the data leaf, each may include multiple operations of queries on tree nodes and leaves, with potentially long periods of concurrent updating and searching. A temporal miss occurs when the multi-threaded system using the shared database has a race condition between the data being updated and the data being retrieved.


A method for controlling an image reading apparatus that scans an image from a document, includes (a) acquiring read position data indicating a reference position where the image reading apparatus performs scanning operations, and (b) setting a reading region that defines, based on the acquired read position data, a range that is used when the image reading apparatus scans an image.

There have been known flatbed type image reading apparatuses having a document table and configured to read a document placed on the document table. For example, Japanese Patent Application Publication No. 08-274972 discloses a flatbed type image reading apparatus that reads a document with its corner aligned at the corner of the document table.

Image reading apparatus and image reading method


A storage stores at least one set of registration data comprising a plurality of tone setting parameters. An instruction section instructs readout of the registration data set from the storage. A controller makes a setting such that the parameters in the registration data set are used in response to an instruction for reading out the registration data set, and makes a setting such that at least one or some of the tone setting parameters in the one set of registration data are used at delayed readout timing later than a time point at which the instruction has been issued. Thus, two or more sub-sets of the parameters in the registration data set can be set to be used at mutually different timing. Namely, a sub-set of the parameters can be set to be used at delayed readout timing later than a time at which a readout instruction has been issued.

The present invention relates to a technique for delayed registration data readout (or recall) in an electronic music apparatus and more particularly to an electronic music apparatus employing a novel delayed registration data readout (or recall) technique. The present invention also relates to a method for reading out registration data from a storage device in accordance with the delayed registration data readout technique, and a computer program for implementing the method or a non-transitory storage medium storing such a program.
A set of "registration data" (or registration data set) comprises settings of a plurality of parameters, such as a tone color and an accompaniment style, (hereinafter referred to as "parameter settings") that are handled as a set of data. Heretofore, electronic music apparatus have been known, in which a plurality of such sets of registration data are prepared and stored in a memory in advance (e.g., prior to a music performance), and in which, during the performance, any desired set of registration data is read out and set at desired timing so as to simultaneously switch previous parameter settings to a tone color, accompaniment style, etc. included in the desired set of registration data.
A performance apparatus employing such an electronic music apparatus is known, in which, once readout (or recall) of a given set of registration data is instructed, only one or some of the parameter settings, not all of the parameter settings, included in the given set of registration data are read out (or recalled) and set into the apparatus (see, for example, Japanese Patent Application Laid-open Publication No. HEI-11-224086 that corresponds to U.S. Pat. No. 6,031,175). In this conventionally-known performance apparatus, once readout of a set of registration data including a first parameter not related to an automatic accompaniment and a second parameter related to an automatic accompaniment is instructed, only the first parameter is read out and set into the apparatus.
However; with the aforementioned conventionally-known performance apparatus, even when only one or some parameters are to be read out, it is necessary to read out the entire of a set of registration data, requiring one separate readout operation per parameter use timing. Therefore, with the conventionally-known performance apparatus, different types of parameters to be used at different timing have to be prepared as different sets of registration data. Thus, the conventionally-known performance apparatus would necessitate increased user's time and labor, increased consumption of memory capacity due to such redundant registration data and increased number of user's operations for reading out the registration data.

Delayed registration data readout in electronic music apparatus


This method, for regenerating a member used in a device that treats seawater, involves a cleaning step for removing deposits from the member. In the cleaning step, a first chemical solution containing an acid other than hydroxydicarboxylic acid and a second chemical solution containing hydrogen peroxide, a heavy metal compound and hydroxydicarboxylic acid are used.

Techniques for purifying raw water such as river water, lake water, groundwater, stored water, sewage, and industrial wastewater using a microfiltration membrane, an ultrafiltration membrane, or a reverse osmosis membrane are known.
When carrying out membrane filtration of raw water, substances having a size exceeding the membrane pore size (for example, matter suspended in the raw water) are blocked by the filter used in the filtration, whereby concentration polarization occurs or caking may be generated in some cases. These become contaminants of the filter, blocking the pores of the filter, increasing the filter resistance, increasing the transmembrane pressure, and decreasing the filter flow rate. Filters in which the transmembrane pressure difference has risen to a predetermined value are reused after removing the contaminants by cleaning, restoring the filter flow rate to its initial value.
Patent Literature 1 relates to a cleaning agent for cleaning such a filter, and proposes a cleaning agent for separation membranes comprising a hydroxy dicarboxylic acid, hydrogen peroxide, and a heavy metal compound.
It is considered that the cleaning agent for cleaning a filter used in the purification of raw water can be used for cleaning members used in devices for treating raw water, such as plumbing, strainers, valves, or pumps.

Method of regenerating member and method of seawater desalination


A system and method determine a size and a shape for identical geodesic modules that are used to form a structure. The system and method may include analyzing input data regarding a size and a shape of the structure to be formed, and determining the size and the shape for each of the identical geodesic modules based on the size and the shape of the structure to be formed. The structure may include a framework including the identical geodesic modules. Each of the geodesic modules has a size and a shape that are the same as all of the other of the geodesic modules. A forming system and method position a framework and a covering skin of the structure in relation to a mandrel, and drill and rivet the framework to the covering skin with a plurality of operating heads.

Various vehicles are formed through numerous components. For example, a fuselage of an aircraft may be formed through various stringers, frames, bulkheads, keel beams, and the like that are secured together through numerous fasteners, such as rivets. As can be appreciated, the process of forming the fuselage section is time and labor intensive.
Geodesic airframes have also been used to form fuselages. Known geodesic airframes have a variable (that is, non-constant) cross-section throughout. Accordingly, every separate and distinct element of known geodesic airframes has a unique and distinct shape. Consequently, a large number of geodesic parts, each or nearly each of which is different, are stored and assembled together. As such, the process of locating and assembling such a large number of separate and distinct parts is complicated, time-consuming, and labor-intensive. In short, the assembly process is akin to a large puzzle, in which a large number of unique parts are located and connected together.
Additionally, the process of assembling semi-monocoque structures (such as a fuselage of an airframe) is typically manually performed with fixed jigs. Due to the repetitive nature of such an assembly process, and the small tolerances involved, the assembly of a semi-monocoque structure is time and labor intensive.
Accordingly, a need exists for an efficient system and method of manufacturing a fuselage of a vehicle.

Systems and methods for determining sizes and shapes of geodesic modules


A laser device for emitting waves in a frequency range belonging to the terahertz range, includes the following, in combination: a wave guide extending longitudinally along an axis A-A′; a superconducting coil arranged coaxially to the wave guide and arranged at a first end of the wave guide; a p-Ge p-doped germanium crystal arranged inside the coil such that the turns of the superconducting coil at least partially surround the p-Ge crystal; a cooling device containing a coolant, the superconducting coil and the p-Ge crystal being arranged in the cooling device, and the wave guide partially extending outside the cooling device; and removing the coolant from the wave guide.

The present invention relates to a laser device for emission of waves in the terahertz range. The present invention can have numerous applications. It can apply especially in the fields of medical imaging, security (detection of metals or gases in airports, etc.). It can also enable quality controls.
Sources of terahertz radiation are sources whereof the output signal has a wavelength in the field of far infrared of the electromagnetic spectrum (300 GHz-10 THz). Sources of terahertz radiation are known, such as carcinotrons (or "BWO" for the English expression "Backward Wave Oscillator") or the quantum cascade lasers (or "QCL" for the English expression "Quantum Cascade Laser"). A carcinotron is a tube for generating microwaves which operates by prolonged interaction of an electronic beam and an electromagnetic wave.
A quantum cascade laser is a semiconductor laser capable of emitting a light wave using inter subband transitions in hetero-structures with multiples quantum well. This type of laser theoretically produces quantum yields greater than 1 by "recycling" of carriers. The application of an electrical field allows an electron, once it has emitted a first photon in a first well, to passer by effect tunnel to a following well, and so on. One of the disadvantages of existing sources of terahertz radiation is that they are neither compact nor easy to execute outside a laboratory.
Another disadvantage of existing sources of terahertz radiation is that they do not emit radiation covering all frequencies of the terahertz range. In fact, a carcinotron is capable of emitting radiation in frequencies of less than or equal to 1.5 THz. A quantum cascade laser is as such capable of emitting radiation in frequencies greater than or equal to 2.5 THz. Existing sources of terahertz radiation therefore do not emit radiation in a frequency range between 1.5 THZ and 2.5 THz.
An aim of the present invention is to propose a compact laser device. Another aim of the invention is to propose a laser device capable of emitting a wave in a frequency range between 0.5 THz and 5 THz, and preferably between 1.2 and 2.8 THz.
For this purpose the invention proposes a laser device for wave emission in a frequency range in the terahertz range, comprising in combination:                waveguide extending longitudinally according to an axis A-A′, the waveguide comprising a proximal end and a distal end,        a superconducting coil coaxial to the waveguide and arranged at the level of the proximal end of the waveguide,        a p-Ge p-doped germanium crystal arranged inside the coil such that the windings of the superconducting coil at least partially enclose the p-Ge crystal,        cooling means containing coolant in the liquid state, the superconducting coil and the p-Ge crystal being arranged in the cooling means and the waveguide extending partially to the exterior of the cooling means, means for eliminating coolant in the liquid state in the waveguide, said means comprising two windows transparent to the light radiation in the terahertz range at the level of the proximal and distal ends of the waveguide.
Preferred, though non-limiting, aspects of the device according to the invention are the following:                the means for eliminating coolant in the liquid state in the waveguide replace it with coolant in the gaseous state,        the means for eliminating coolant in the liquid state in the waveguide also comprise a heating element in thermal contact with the waveguide for avoiding coolant condensation,        the means for eliminating coolant in the liquid state in the waveguide comprise a vacuum made in the waveguide,        the windows are made of material transparent in the terahertz range tel such as crystalline quartz, Mylar, Teflon®, crystalline ZnSe, sapphire, high-purity silicon or other high-purity semiconductive crystals,        the window transparent to light radiation positioned at the level of the distal end of the waveguide is a lens,        the device also comprises a resonator comprising at least two mirrors deposited on two respective plates of high-purity germanium crystal in contact with the p-Ge crystal, the p-Ge crystal being arranged between the crystal germanium plates according to the axis A-A′ of the waveguide, the mirrors are made of material selected from silicon dioxide SiO2 and high-purity germanium,        the mirror the farthest from the waveguide is spherical,        the device also comprises a convergent lens arranged inside the waveguide such that:                    the distance between said lens and the resonator is the greatest possible, and            the light beam originating from the resonator does not come into contact with the internal walls of the waveguide,                        the focal distance of the convergent lens is selected such that the light beams exiting from said convergent lens do not come into contact with the walls of the waveguide,        the waveguide comprises a divergent cone trunk and a tube coaxial to the divergent cone trunk, the tube extending at the level of the large base of the cone trunk, the small base of the divergent cone trunk forming the first end of the waveguide,        the superconducting coil comprises at least two layers of windings, each winding of a new layer being positioned in a hollow formed by two adjacent windings of the preceding layer.

Laser device for emitting waves in the terahertz range

Centre National de la Recherche Scientifique (CNRS)

Universite Montpellier 2 Sciences et Techniques


A two-class classification/prediction model is generated in a simple operation by performing two-class classification with a classification rate substantially close to 100%. The two-class classification/prediction model is generated by a) obtaining a discriminant function for classifying a training sample set into two predetermined classes on the basis of an explanatory variable generated for each sample contained in the training sample set, b) calculating a discriminant score for each training sample by using the obtained discriminant function, c) determining, based on the calculated discriminant score, whether the training sample is correctly classified or not, d) determining a misclassified-sample region based on maximum and minimum discriminant scores taken from among misclassified samples in the training sample set, e) constructing a new training sample set by extracting the training samples contained in the misclassified-sample region, and f) repeating a) to e) for the new training sample set.

A classification problem learns a rule for classifying samples into a predetermined plurality of classes from a set of samples each known to belong to one of the classes, and predicts the class to which a sample of unknown class belongs by using the learned rule as a prediction model. Among others, a two-class classification which classifies a sample set into two classes is the most basic classification, and has long been used in structure-activity relationship research and structure-property relationship research; in recent years, the two-class classification has been attracting attention as a useful technique for testing chemicals for toxicity, etc. Methods for learning rules, i.e., classification methods, include linear discriminant analysis methods, such as linear learning machine, discriminant analysis, Bayes linear discriminant analysis, SVM (Support Vector Machine), AdaBoost, etc., and nonlinear discriminant analysis methods, such as Bayes nonlinear discriminant analysis, SVM (Support Vector Machine+Kernel), neural networks, KNN (K-Nearest Neighbor), decision tree, etc.
Generally, in a classification problem, misclassification is unavoidable, and it is difficult to achieve a classification rate of 100%. The term "classification rate" is a measure that indicates how correctly samples for which the classes they belong to are known have been classified, while "prediction rate" is a measure that indicates how correctly samples for which the classes they belong to are not known have been classified. Basically, the "prediction rate" does not exceed the "classification rate." Accordingly, if the "classification rate" is raised, the upper limit of the "prediction rate" automatically increases. This means that if the classification rate can be raised, the prediction rate improves. Further, from the general characteristics of data analysis, it is well known that as the number of samples used to generate a prediction model increases, the number of misclassified samples also increases and as a result, the classification rate drops. A misclassification is an instance in which a sample that may belong to class 1, for example, is wrongly classified as a sample belonging to class 2. The major reason for this is that as the total number of samples used increases, the absolute number of samples that cause noise in the classification also increases. Unlike statistical techniques, powerful data analysis techniques, such as multivariate analysis or pattern recognition are susceptible to noise, and in most cases, increasing the number of samples will end up making the data analysis difficult.
As a field that requires high classification/prediction rates, the field of chemical toxicity evaluation is gaining importance from the standpoint of environmental protection. In this field, chemicals are often classified into two classes, a toxic chemical group (class 1) and a nontoxic chemical group (class 2), but since the factors contributing to the manifestation of toxicity are complex and diverse, as is always the case in this field, misclassification can easily occur and if the current state of the art of data analysis is applied, it is difficult to raise the classification rate.
It is also to be noted that no matter how high the classification rate is obtained, if the number of samples used is large, the number of misclassified samples becomes large. For example, when classifying toxic chemicals and nontoxic chemicals, if the number of samples used for training is large, for example, if the classification is to be performed using 10000 chemicals, a classification rate of 90% would mean that 1000 chemicals would be misclassified, the number being large enough to become a problem. Further, in the field of toxicity classification, if chemicals having no toxicity were misclassified as chemicals having toxicity (false positive), it would not present a serious problem, but because of the nature of the subject, it would be very dangerous if chemicals having toxicity were misclassified as chemicals having no toxicity (false negative), and such a misclassification should be avoided by all means. From this point also, it is desirable that the classification rate be increased to 100%.
While increasing the prediction rate is the final target of a classification problem, it is now recognized that increasing the classification rate is of utmost concern, and various efforts have been expended for this purpose. As earlier noted, considering the fact that the prediction rate does not exceed the classification rate, if the classification rate is raised, the upper limit of the prediction rate increases. Noting this point, the present inventor has proposed a classification method that can achieve a classification rate as close as possible to 100%, i.e., "K-step Yard sampling method" (hereinafter referred to as the KY method) (Non-patent document 1, PCT/JP-2007/056412).
To briefly describe this method, first a training sample set is constructed using samples known to belong to a first class and samples known to belong to a second class. Then, by performing discriminant analysis on the training sample set, a first discriminant function (hereinafter called the AP model) that achieves a high classification rate, for example, a classification rate of substantially 100%, for the first class and a second discriminant function (hereinafter called the AN model) that achieves a high classification rate, for example, a classification rate of substantially 100%, for the second class are generated. Next, objective variables of each sample are calculated using the two discriminant functions, the AP model and the AN model, and samples for each of which the values of the objective variables, i.e., the classification results, match between the two discriminant functions and samples for each of which the results do not match are identified.
Since the AP and AN models provide a classification rate of nearly 100% for the first and second classes, respectively, any sample whose classification results match between the AP and AN models is identified as a correctly classified sample. Accordingly, any sample whose classification results match is assigned to class 1 or class 2, whichever is identified. On the other hand, any sample whose classification results do not match between the AP and AN models is assigned to a gray class, i.e., a third class where no class determination is made.
When the gray class in the first stage is thus formed, the samples assigned to the gray class are grouped together to form a new sample set. Then, the AP model and the AN model are newly generated for this sample set, and the samples are classified in the same manner as described above. As a result, the gray class in the second stage is formed; thereafter, the gray class in the third stage, the gray class in the fourth stage, etc., are formed in a similar manner. By repeating the gray class formation until the number of samples assigned to the gray class finally decreases to zero, all the samples can be correctly classified into the first and second classes, respectively. That is, a classification rate of 100% is achieved.    Non-patent document 1: "Development of K-step Yard Sampling Method and its Application to ADME-T Predictions," 34th Structure-Activity Correlation Symposium, November 2006    Non-patent document 2: "Chemical Data Analysis Techniques by Tailor-Made Modeling," 30th Symposium on Chemical Information, November 2007

This patent is subject to a terminal disclaimer.

Method, program, and apparatus for generating two-class classification/prediction model


A device for activating a signal emitter for use in a firefighter locator system operates in conjunction with the firefighter's self-contained breathing apparatus (SCBA). The activation device includes a pressure sensor to monitor pressure on an air line that delivers air from the SCBA air tank to the SCBA air regulator. When the firefighter opens the SCBA air tank valve, pressure is sensed in the air line and the emitter is activated to transmit a signal. The signal is received by base stations that then use the signal to locate/track the signal emitter. Preferably, the activating system also includes a user operated reset button(s) and a shutoff circuit to allow the user to stop transmission of the signal by the signal emitter. The shutoff circuit is designed to stop transmission of the signal only after the air line has been depressurized and the reset button(s) is depressed.

There are many circumstances wherein there is a need to establish the accurate positioning and tracking of movable objects or individuals. This is particularly so when the individual or object is moving in a hostile or dangerous environment. One example is when a firefighter enters a structure during a rescue operation. In situations such as this, there is a need to determine the position of the firefighter from outside the structure with accuracies of approximately one meter. Although an object's position can be determined effectively outdoors using the current global positioning system (GPS), the GPS system is unsuitable, without augmentation, for locating moving objects indoors at accuracies of approximately one meter.
To accurately locate and track objects or individuals inside or adjacent to a structure, the tracking signal that is used by the system must have good penetration and little distortion through the walls and other features of the structures. Lack of-adequate signal penetration can result in a loss of signal strength which in turn can cause unacceptable location errors. Also, the signal should have low deflection (refraction and diffraction) to reduce the presence of multipath signals which limit location accuracy. Further, to locate an object's position accurately indoors, a system must provide sufficient coverage, and be able to acquire the signals quickly.
Unfortunately, radiofrequency (RF) systems using high frequency signals are limited in their ability to penetrate the walls and features of a structure. Also, because high frequency signals have wavelengths that are much shorter than the size of typical structural features such as rooms, hallways and staircases, these features can act as waveguides for the high frequency waves, altering the path of the signal. On the other hand, low frequency RF signals offer the potential to penetrate the walls and features of a structure and overcome inaccuracies due to fading and path length perturbations caused by diffraction and reflection. Further, since the wavelength of the low frequency waves are approximately the same or greater than the size of typical structural features, the features do not act as waveguides. Consequently, low frequency RF signals having wavelengths approximating the size of structural features are preferred over high frequency signals for use in and around structures.
Traditional positioning technologies use time-of-arrival and the angle-of-arrival methods. In a typical time-of-arrival system, the system measures the time of arrival of a marker modulated onto a signal to determine range. However, in time-of-arrival systems, increased resolution can only be obtained at the expense of increased bandwidth. By way of example, for a desired locating accuracy of one meter, a ranging system based on time of arrival would require a bandwidth on the order of tens of MHz. Unfortunately, this much bandwidth (tens of MHz) is unavailable at the low frequencies required for indoor use.
Another traditional positioning technology is the angle-of-arrival system. Typically, the angle of arrival is measured with array antennas or spinning real-aperture antennas. To achieve an unambiguous angle measurement commensurate with a one meter cross-range resolution at a one kilometer distance, each individual antenna (or array) must be on the order of 15 wavelengths across. Consequently, for the low frequency RF signals required for indoor locating, each antenna would be quite large and costly. Further, such large antennas would be unsuitable for a firefighter locator system which requires small, portable equipment that can be setup quickly.
Another technique for locating the position of an object includes establishing several known locations to receive a signal emitted from the object. By measuring the phase delay of a cyclostationary feature of the signal at each of the known locations, the position of the object can be determined. For example, U.S. Pat. No. 5,999,131 which issued to Sullivan for an invention entitled "Wireless Geolocation System," and which is assigned to the same assignee as the present invention, discloses a system for locating mobile phones within a cell which may comprise several square miles. Unlike a mobile phone system which broadcasts over relatively high frequencies and large distances, the present invention is focused on using low frequency RF signals having the ability to penetrate the walls and floors of structures. Further, whereas it is sufficient to locate a mobile phone within a cell to an accuracy of about 50 feet, the present invention is concerned with locating an object positioned inside a structure to an accuracy of one meter.
During a typical rescue operation, only a portion of firefighters and other emergency personnel that arrive at the scene may actually enter the structure and require locating/tracking. Although it is preferable to supply each firefighter with a signal emitter in case that firefighter is required to enter the structure, it is also preferable to disable each signal emitter until it is needed (i.e. until the corresponding firefighter is required to enter the structure). This reduction in overall signal generation at the site reduces signal clutter and allows for higher system resolution for the activated signal emitters. It is also preferable to have a signal emitter activation system that does not rely on the firefighter to manually activate the signal emitter. It is also desirable to stop the emitter from signal transmission after a firefighter safely exits the structure. Importantly, the mechanism for emitter shutdown should contain safety features to prevent inadvertent emitter shutdown while the firefighter remains in the structure.
Considering the above, it is an object of the present invention to provide a wireless system for locating and tracking the position of a movable signal emitter situated inside a structure with accuracies of approximately one meter. Another object of the present invention is to provide a wireless system for accurately locating the position of a signal emitter that uses penetrating, low frequency RF signals, and requires only a minimal amount of bandwidth. Still another object of the present invention is to provide a wireless system for accurately locating and tracking the position of a plurality of signal emitters situated inside or adjacent to a structure. It is another object of the present invention to provide a system for automatically activating a firefighter's signal emitter before the firefighter enters a structure. Still another object of the present invention is to provide a system for signal emitter shutdown that contains safety features to prevent inadvertent signal emitter shutdown while the firefighter remains in the structure. Yet another object of the present invention is to provide a wireless locating system that can incorporate a bi-directional data link and is simple to use, and comparatively cost effective.


A dynamic valve mechanism in an internal combustion engine for opening and closing a valve by swinging a rocker arm in accordance with rotation of a cam shaft. The valve mechanism includes a rocker shaft for swingably supporting the rocker arm, a positioning portion fixedly mounted on the rocker arm and projecting in the axial direction of the rocker shaft, and a thrust bearing portion mounted on the cylinder head for supporting the rocker shaft through a holding portion thereof and projecting toward the rocker arm side in order to position the rocker arm by contact with the positioning portion.

An internal combustion engine, for example, a multivalve type internal combustion engine includes a dynamic valve mechanism which has two intake valves and two exhaust valves in one combustion chamber, the two intake valves being simultaneously opened and closed at a certain valve timing, and the two exhaust valves being simultaneously opened and closed at another valve timing.
As for the dynamic valve mechanism, there are many types of them such as a push rod type in which a push rod is used in order to increase reliability and degree of freedom for designing the configuration of a combustion chamber, a rocker arm type in which an overhead cam is used in order to increase degree of freedom for designing the configuration of the combustion chamber and to increase degree for designing the configuration of an intake hole, a swing arm system in which a swing arm is used in order to minimize the equivalent weight of a valve side of a dynamic valve system, and a direct drive system in which no rocker arm is used and a tappet is directly driven from immediately above the valve and is suitable for use in a high speed combustion engine having the highest characteristic number of vibration.
Also, as another dynamic valve mechanism, there is a mechanism having a circular conical contact surface with respect to a supporting member for supporting a rocker shaft and a rocker arm as disclosed in Japanese Utility Model Early Laid-open Publication Sho. No. 58-79004.
In the conventional dynamic valve mechanism of an internal combustion engine, as shown in FIGS. 5 and 6, a rocker arm 120 is disposed within a cam chamber 106 of a cylinder head 104 with one end thereof contacted with a valve stem end of a valve disc (not shown) and with the other end contacted with a cam portion 112a of a cam shaft 112. In order to swingably support the rocker arm 120, a rocker shaft 126 is thrust into a bearing portion 130 and a spring 142 of the rocker arm 120, and the rocker arm 120 is held by a holding portion 144 within the cam chamber 106. At this time, the side surface of the rocker arm 120 is urged against the side surface portion of the holding portion 144 by the energizing force of the spring 142 and the rocker arm 120 is positioned by the holding portion 144.
As a result, the conventional mechanism has a shortcoming in that because the holding portion 144 must be extended until it reaches the rocker arm 120, the thickness of the holding portion 144 in the axial direction with respect to the rocker arm 120 becomes large and, therefore, a large quantity of material is required when the holding portion 144 is manufactured and this is economically disadvantageous.
Also, it has a further shortcoming in that because of the large size of the holding portion 144, a large weight of the dynamic valve mechanism 110 of the internal combustion engine 102 is created. In addition, degree of freedom for carrying out layout of the dynamic valve mechanism 110 is limited and thus disadvantageous in actual use.
It is therefore an object of the present invention to realize a dynamic valve mechanism in an internal combustion engine in order to eliminate the above-mentioned shortcoming, which includes a rocker shaft for swingably supporting the rocker arm, a positioning portion mounted on the rocker arm and projecting in the axial direction of the rocker shaft, and a thrust bearing portion mounted on said cylinder head for supporting said rocker shaft through a holding portion thereof and projecting toward the rocker arm side in order to position the rocker arm by contact with the positioning portion. Owing to the foregoing construction, the quantity of material required at the time when the holding portion is manufactured can be minimized and this is thus economically advantageous. In addition, the dynamic valve mechanism can be made light in weight and degree of freedom for carrying out a layout of the dynamic valve mechanism can be enlarged.
In order to achieve this object, according tot he present invention, there is provided a dynamic valve mechanism in an internal combustion engine for opening and closing a valve body by swinging a rocker arm in accordance with rotation of a cam shaft, said dynamic valve mechanism in an internal combustion engine being characterized by including a rocker shaft for swingably supporting said rocker arm, a positioning portion mounted on said rocker arm and projecting in the axial direction of said rocker shaft, and a thrust bearing portion mounted on said cylinder head for supporting said rocker shaft through a holding portion thereof and projecting toward said rocker arm side in order to position said rocker arm by contact with said positioning portion.
Owing to the above-mentioned construction, at the time when the rocker arm is mounted, the rocker arm is swingably supported by the rocker shaft and this rocker shaft is carried on the cylinder head through the holding portion.
At this time, the positioning portion of the rocker arm is urged by the thrust bearing portion provided on the cylinder head, so that the rocker arm is positioned in a predetermined position.
BRIEF DESCRIPTION OF THE DRAWINGS
An embodiment of the present invention will be described in detail with reference to the drawings wherein:
FIG. 1 is an enlarged sectional view of a portion of a dynamic valve mechanism of the present invention in an internal combustion engine.
FIG. 2 is a schematic enlarged view of the dynamic valve mechanism in an internal combustion engine.
FIG. 3 is a schematic plan view of the dynamic valve mechanism in an internal combustion engine.
FIG. 4 is a schematic sectional right side view of the dynamic valve mechanism in an internal combustion engine.
FIG. 5 is a schematic plan view of a prior art dynamic valve mechanism in an internal combustion engine, and FIG. 6 is a schematic sectional front view thereof.

Dynamic valve mechanism of internal combustion engine


An oil recovery method may include injecting 0.05 to 0.25 pore volumes of low-salinity water having 4,000-8,000 ppm of total dissolved solids into a reservoir, and then applying seismic stimulation to the reservoir for a predetermined duration. The steps of injecting low-salinity water and applying seismic stimulation are repeated until 0.25 to 1.0 pore volumes of the low-salinity water has been added to the reservoir. Then, high-salinity water having 35,000 to 57,000 ppm of total dissolved solids is introduced to the reservoir.

During primary oil recovery, oil inside an underground hydrocarbon reservoir is driven to the surface (for example, toward the surface of an oil well) by a pressure difference between the reservoir and the surface. However, only a fraction of the oil in an underground hydrocarbon reservoir can be extracted using primary oil recovery. Thus, a variety of techniques for enhanced oil recovery are utilized after primary oil recovery to increase the production of hydrocarbons from an oil well. In enhanced oil recovery, a fluid is typically introduced through an injection well that is in fluid communication with the underground hydrocarbon reservoir in order to re-pressurize the reservoir and displace oil toward the surface. Some examples of these techniques include water flooding, chemical flooding, and supercritical CO2 injections. These techniques require the use of significant amounts of water and/or other chemical constituents in order to effectively recover oil from subterranean formations. They also may suffer from inefficient oil recovery due to oil being dispersed in water phases, making separation and recovery from a well challenging.

Seismic assisted flooding processes for oil recovery in carbonates


Provided is a digital duty cycle corrector for a multi-phase clock application which includes a flip-flop receiving a signal having a first clock cycle as an input and generating a reference signal having a cycle twice the first clock cycle, a duty corrector generating a signal having a second clock cycle that is half the cycle of the reference signal, from the reference signal, a duty detector measuring an amount of a duty error of the second clock cycle signal and generating a digital code value to control a duty cycle of the second clock cycle signal becomes 50%, and a phase inverter inverting a phase of the second clock cycle signal by 180° such that a rising edge of the second clock cycle signal is always fixed constantly regardless of a duty cycle correction operation.

1. Field of the Invention
The present invention relates to a duty clock of a clock, and more particularly, to a duty cycle corrector of an internally generated clock.
2. Description of the Related Art
Since all blocks of a duty cycle corrector can be embodied with digital logic, operation characteristics of the duty cycle corrector with respect to changes in operating temperature, process, and power voltage are superior and a correction to distortion of an input clock duty in a wide range is possible. Since phase information between multi-phase clocks is constantly maintained, an application of the duty cycle corrector to a system needing the multi-phase clock is possible. Also, since the duty information is stored as a digital code value, a quick switch from a ready mode to a normal operation mode is possible.
In an SDRAM (DDR-SDRAM) using both rising edge and falling edge of a clock and circuits such as a MUX/DEMUX for a high speed data transmission, a clock accurately maintaining a 50% duty cycle is a core factor in determining performance of an overall system. Furthermore, in an application such as a pipeline analog-to-digital converter (pipeline-ADC), in addition to correction to accurately maintain the 50% duty cycle, constantly maintaining phase information between multi-phase clocks is also important.
FIGS. 1A and 1B show conventional analog duty cycle correctors used to solve the duty cycle problem. FIG. 1A shows an example of a conventional analog duty cycle corrector. The analog duty cycle corrector includes a duty cycle correction unit 110 and a control voltage generator 120.
The input and output of the duty cycle correction unit 110 and the control voltage generator 120 is a double-input/double-output system having a complementary value. The control voltage generator 120 generates an analog offset voltage proportional to a duty cycle to maintain a clock duty cycle by 50%. The duty cycle correction unit 110 corrects a duty cycle of a clock by receiving the analog offset voltage as a control voltage.
The above method having merits such as a small chip size and a low power consumption has been widely used. However, since the method is characteristically sensitive to a change in temperature, process, and voltage according to the configuration of an analog circuit. Also, the method has a demerit of losing duty cycle correction information in a ready mode in which a power voltage decreases or the operation of an analog circuit portion is discontinued.
Since the inclination of a rising portion and a falling portion of an input clock must be gentle for accurate operation, coercing a duty cycle is with respect to a high speed clock is difficult. Also, during the correction of a clock duty cycle, since both phases of the rising portion and the falling portion of a clock change, phase information of each clock with respect to a multi-phase clock is not maintained.
Thus, according to the above method, the duty cycle of an input clock must be over 40% because a range of an adjustable offset voltage is limited and a range of change of the inclination of the rising portion and the falling portion of the input clock is limited.
FIG. 1B shows another example of the conventional analog duty cycle corrector.
Two voltage controlled delay lines (VCDLs) 130 and 135 and a pulse width detector 150 perform the same function as the duty cycle correction unit 110 of FIG. 1A. The amount of delay of a coarse VCDL 130 is fixed to a value less than 50% of an input clock cycle while the amount of delay of a fine VCDL 135 is adjusted to an output voltage of an op-amp 170. The amount of delay of each VCDL is controlled by a negative feedback loop such that the total amount of delay after passing through the two VCDLs 130 and 135 is 50% of an input clock cycle.
The pulse width detector 150 having a function similar to that of a phase detector of a PLL generates an output clock CLK_OUT having a duty that is corrected using a rising edge of an input clock and a rising edge of a clock passing through the delay lines. Since a rising point of the output clock CLK_OUT is determined by the input clock and a falling point of the output clock CLK_OUT is determined by a delayed clock, the rising edge of the output clock CLK_OUT can maintain information on the input clock during a duty correction process. According to the characteristic in an operation method of the pulse width detector 150, since there must be no section in which two input clock are high at the same time, pulse shapers 140 and 145 generate an output signal having a narrow pulse width.
The duty cycle information of the output clock CLK_OUT can be detected by a frequency-voltage converters (FVCs) 160 and 165 and the op-amp 170. The FVCs 160 and 165 convert high time and low time of a clock to a proportional voltage using a capacitor. By using the two FVCs 160 and 165, the effects of the offset and noise of the op-amp 170 are removed.
The above method is appropriate for an application using the multi-phase clock since only the change point of the falling portion of the clock is controlled. Also, correction to an input duty error of 30%-70% at an input frequency of 19 MHz is possible. However, since the amount of delay is still controlled by using an analog voltage, the method is sensitive to the change in temperature, voltage, and process and the method is difficult to be applied to an application in which a ready mode is needed. Furthermore, since the pulse shapers 140 and 145 are used at an input end of the pulse width detector 150 to decrease the pulse width, the method is difficult to operate at a high frequency.

Digital duty cycle corrector for multi-phase clock application


A ball-and-ramp mechanism of a thrust generator includes a rotary ramp member and a rectilinear ramp member, each having a plurality of sloped grooves sloped along a circumferential direction and having an arcuate diametrical cross-section, and a spherical member interposed between the sloped grooves of the ramp members to transmit force from the rotary ramp member to the rectilinear ramp member. Each of the sloped grooves has regions varying in the curvature radius of the diametrical cross-section in a track area where the spherical member contacts the sloped groove. Accordingly, it is possible to improve the durability of the rotary ramp member and the rectilinear ramp member.

The present invention relates to a thrust generator and a disk brake using the thrust generator.
There has heretofore been a disk brake for a vehicle that propels a piston to press a brake pad against a disk to apply braking force to the vehicle by using a thrust generator that converts rotational force input thereto from an electric motor or the like into rectilinear motion through a ball-and-ramp mechanism, as disclosed in Japanese Patent Application Publication No. 2002-13568.
The disk brake disclosed in Japanese Patent Application Publication No. 2002-13568 suffers, however, from the following drawback. The ball-and-ramp mechanism has a pair of ramp members with sloped grooves and a spherical member interposed between each pair of mutually opposing sloped grooves. Each sloped groove is formed such that the curvature radius of the diametrical cross-section of the groove is constant along the circumferential direction throughout a track area where the spherical member contacts the sloped groove. Therefore, durability is undesirably degraded in specific regions of the sloped groove.


The invention relates to the prevention of the odor caused by the action of bacteria on cat urine in a cat litter box. The cat liter box has a base and walls and is provided with a sorbtive-desiccant member for the collection of animal urine. Litter is in direct moisture transfer contact with the sorbtive-desiccant member. The odor prevention process includes the steps of transferring cat urine directly from granular particles, to the sorbtive-desiccant member, sorbing the urine in a sorbtive-desiccant member having high surface area and high urine sorbency, dispensing the urine quickly in said sorbtive-desiccant member, and evaporating said urine from said high surface area sorbtive-desiccant member through the granular particles. The sorbtive-desiccant member maintains the urine in a medium which subjects the bacteria in the urine to the effects of drying. The granular particles are non-absorbent particles having sufficiently large diameter to provide sufficient interparticle spacing to permit free flow of urine from the particles to the sorbtive-desiccant member and the free flow of moisture from said sorbtive-desiccant member to the air. The base of the litter box prevents urine from leaving one side of said sorbtive-desiccant member. Thereby the bacteria, which are capable of breaking down cat urine, die or become dormant and thus prevent significant odor formation.

1. Field of the Invention
This invention relates to a specific non-absorbent litter for use in combination with an absorbent medium for odor prevention in animal litter units. In particular the litter can be a mineral particle, such as coarse sand, and the absorbent pad can be a disposable, sorbent/dessicant pad-liner system.
2. Brief Description of the Prior Art
Many domestic animals frequently use litter boxes for the elimination of body wastes. The boxes are usually filled with various kinds of granualr materials such as sand, cat litter and the like, and must be periodically emptied and cleaned, which are somewhat objectionable tasks, since the abosrbent granular material must be replaced and the boxes cleaned each time.
Cats, being the most frequent users of litter boxes, present a further problem in that the urine of the feline contains the highest content of urea which, when allowed to stand for any length of time in any sorbent material, releases an ammonia odor. This odor is one of the more objectionable factors in the ownership of a cat.
In order to eliminate the odor caused by cat urine, the litter box must be changed frequently, necessitating the expensive, laborious and unpleasant chore.

Non-absorbent litter for use with absorbent pad


A method of generating a customized secondary power distribution assembly (SPDA) includes generating one or more customizable SPDAs. Each of the one or more customizable SPDAs is a construct corresponding with a microprocessor configured to control a set of customizable channels in each of a set of virtual line replaceable modules (vLRMs). The method also includes creating a mapping between one of the one or more customizable SPDAs and the customized SPDA, the mapping indicating line replaceable modules (LRMs) of the customized SPDA and defining each channel of each LRM, and deploying the customized SPDA in an application. The microprocessor is initiated to control the customized SPDA according to the mapping at startup.

Exemplary embodiments pertain to the art of power distribution and, in particular, to a customized secondary power distribution assembly (SPDA) generated from a customizable SPDA.
In aircraft and other applications, a number of electronic systems include electronic components that require alternating current (AC) or direct current (DC) power to function. A primary power assembly generates power, while a secondary power distribution assembly (SPDA) transforms or coverts the power from the primary power assembly to supply powered equipment. The SPDA supplies both AC and DC powered equipment.

Customized secondary power distribution assembly generated from customizable secondary power distribution assembly


Prior to transitioning a multiple-displacement engine from a full-displacement engine operating mode to a partial-displacement engine operating mode, a base slip rate of a torque converter coupled to the engine engine is increased by a predetermined slip rate offset. The engine is then transitioned to partial-displacement mode upon the earlier of either achieving the desired offset slip rate, or once a maximum time delay has occurred since the slip rate offset was enabled. An offset slip rate is maintained throughout partial-displacement engine operation, and through a transition back to a full-displacement mode. The slip rate offset is removed or disenabled once the engine is again operating in the full-displacement mode. The slip rate offset is either a calibratable constant or is determined as a function of one or more suitable engine or vehicle operating parameters affecting vehicle NVH levels, such as engine speed and vehicle speed.

The prior art teaches equipping vehicles with "variable displacement," "displacement on demand," or "multiple displacement" internal combustion engines in which one or more cylinders may be selectively "deactivated," for example, to improve vehicle fuel economy when operating under relatively low-load conditions. Typically, the cylinders are deactivated through use of deactivatable valve train components, such as the deactivating valve lifters as disclosed in U.S. patent publication no. US 2004/0244751 A1, whereby the intake and exhaust valves of each deactivated cylinder remain in their closed positions notwithstanding continued rotation of their driving cams. Combustion gases are thus trapped within each deactivated cylinder, whereupon the deactivated cylinders operate as "air springs" while a corresponding increase in intake manifold pressure operates to reduce engine pumping losses. When vehicle operating conditions are thereafter deemed to require an engine output torque greater than that achievable without the contribution of the deactivated cylinders, as through a heightened torque request from the vehicle operator based upon a detected intake manifold air pressure representing a current engine load, the deactivatable valve train components are returned to their nominal activated state to thereby "reactivate" the deactivated cylinders.
To provide an improved driving experience, the prior art has sought to reduce driver-perceptible engine torque disturbances during mode transitions by adjusting spark timing, throttle position, and fuel before, during, and/or after the transition, until a steady state at the new operating mode has been achieved.
Additionally, if, at the time of a transition from a full-displacement operating mode to a cylinder-deactivation "partial-displacement" operating mode, a vehicle is equipped with a torque converter that is not already operating at a maximum slip rate, the prior art teaches allowing greater torque converter slip during the transition to thereby dampen the torque pulses generated during the transition. After the transition, the slip rate is lessened, for example, to a lockup condition to thereby promote improved vehicle fuel economy in the ensuing partial-displacement mode.
Unfortunately, in some instances, such slip rate reductions after transitioning to a partial-displacement mode undesirably increase vehicle noise, vibration, and harshness (NVH) levels, particularly at lower engine and vehicle speeds, thereby reducing the system's transparency to vehicle passengers.

Torque converter slip control for multi-displacement engine


A device for preventing a pinched or sandwiched condition includes a first member having therein an opening area; a second member opening and closing the opening area of the first member; and an electronic control device detecting a sandwich condition between the first member and the second member which is in movement at a speed for closing the opening area of the first member when a deceleration side condition of the speed of the second member exceeds a threshold value which is obtained based on an acceleration side condition of the speed of the second member.

Sometimes a substance, device or a part of human body is held between the inner periphery of an opening area and a moving element or member (e.g., a vehicle window or door such as a sliding window or door) which is adapted to be moved for closing the opening area. To prevent damage of the substance or device, or injury to the part of the human body resulting from such a sandwiched condition, the moving member is designed to be reversed by operation of the drive device for preventing the sandwiched condition. Such a device is disclosed in, for example, Japanese Patent Laid-Open Publication No. Hei. 8-260810 published without examination on Oct. 8, 1996.
In this device, the sandwiched condition is recognized when a change of rotational speed of an electric motor which moves the moving member is found. When the moving body is in the form of a sun-roof, a power window pane, or a slide door which is mounted on a vehicle, when the vehicle runs on a rough road or a sloping road, the rotational speed of the motor changes, with the result that the moving body which is in the course of closing the opening area is reversed in spite of no fear of the sandwiched condition.
Accordingly, a need exists for a device for preventing the sandwiched condition for vehicles which is free from the foregoing drawback and disadvantage.

Device for preventing sandwiched condition


Provided is a liquid crystal composition, comprising: one or more compounds of general formula I accounting for 1-30% of the total weight of the liquid crystal composition; one or more compounds of general formula II accounting for 1-30% of the total weight of the liquid crystal composition; one or more compounds of general formula III accounting for 1-20% of the total weight of the liquid crystal composition; and one or more compounds of general formula IV accounting for 30-80% of the total weight of the liquid crystal composition. The liquid crystal composition has at least one of the following properties: a large specific resistance, a high voltage holding ratio, a suitable optical anisotropy, a large dielectric anisotropy, a small viscosity, a low threshold voltage, etc., and is also green and environmentally friendly. The liquid crystal composition is suitable for use in a liquid crystal display device, enabling the liquid crystal display device to have the following properties: a high voltage holding ratio, a short response time, a high contrast ratio, a low energy consumption, and being green and environmentally friendly, etc.

The liquid crystal display devices are used in both direct view display and projection display for numerous information display purposes.
Generally, the display modes include, among others, phase change (PC), twist nematic (TN), super twisted nematic (STN), electrically controlled birefringence (ECB), optically compensated bend (OCB), in-plane switching (IPS), and vertical alignment (VA).
The devices operating in TN and STN modes employ positive dielectric anisotropy liquid crystal, the devices operating in ECB and VA modes employ negative dielectric anisotropy liquid crystal, while those operating in IPS mode may employ both positive and negative dielectric anisotropy liquid crystals.
The display devices may be categorized into passive matrix (PM) and active matrix (AM) according to the driving mode. The latter utilizes thin film transistor (TFT), metal insulator metal (MIM), etc.
Recently, the liquid crystal displays with features such as versatility, large screen, high definition and fast response are more and more popular. Such displays have to be driven in active matrix mode, in which TFTs are used mostly. In an AM-TFT device, the liquid crystal material, as the medium, and the liquid crystal cell constitute a capacitor. But in practice, the capacitor can't hold the voltage till the next refresh frame. To address this, each pixel is provided with a field effect transistor (FET). The pixel electrode is being charged when the TFT is on, while the capacitor is being charged when the TFT is off, until at next cycle the pixel is addressed again. The electric discharge rate of the pixel depends on the capacity of the electrodes and the specific resistance of the dielectric material therebetween. Therefore, a liquid crystal material with high specific resistance and suitable dielectric constant is desirable.
Being provided with a liquid crystal material with high specific resistance, the liquid crystal display device may have increased voltage holding ratio, and as a result, increased contrast ratio. Therefore, it's desirable for the liquid crystal material to have large specific resistance initially and retain a reasonable resistance after prolonged usage.
Being provided with a liquid crystal material with suitable optical anisotropy, the liquid crystal display device may have increased contrast ratio.
Being provided with a liquid crystal material with small viscosity, the liquid crystal display device may have short response time. With a short response time, the liquid crystal display device is suitable for displaying animations. Furthermore, a small viscosity is conducive to the injection of the liquid crystal material into the liquid crystal cell, thereby shortening the injection duration and further improving the operability.
Therefore, it is a goal for those skilled in the art to optimize the liquid crystal material to obtain increased specific resistance, increased voltage holding ratio, suitable optical anisotropy, small viscosity, low threshold voltage and large dielectric anisotropy.
The prior art, such as CN102858918A, teaches a liquid crystal composition with high voltage holding ratio, low power consumption and short response time, however, the prior art is environmentally unfriendly (due to the usage of chlorine compounds) and fails to achieve a balance among such properties as a high specific resistance, low-temperature storage stability, suitable optical anisotropy, high dielectric anisotropy, short response time, low driving voltage and small viscosity required by the liquid crystal television set, flat panel TV and the like.
From the perspective of manufacture, the respective properties of the liquid crystal material are mutually influenced by each other, that is, the increase of certain property may incur changes to other properties. Therefore, it requires inventive efforts to prepare a liquid crystal material with suitable properties on all aspects.
The liquid crystal material is an important component of the liquid crystal display. There are huge demand in the global market for the liquid crystal displays, which are used primarily in the electronic products but suffer from a short operating life. A short operating life implies the problem of waste and pollution, which is more and more unacceptable with the environment-friendliness receiving increasing attention of the public. It would greatly reduce the cost of the disposal of the used liquid crystal displays to select environmentally friendly constituents in preparing the liquid crystal material. Therefore, it requires inventive efforts to prepare a liquid crystal material not only having suitable properties on all aspects, but also being economically feasible and environmentally friendly.
A purpose of the invention is to provide a liquid crystal composition with at least one of the following properties: a large specific resistance, a high voltage holding ratio, a high clear point, a suitable optical anisotropy, a suitable dielectric anisotropy, a small viscosity, a low threshold voltage, etc. To achieve the environmental friendliness, the invention forgoes the chlorine monomer for difluoroether monomers. The difluoroether monomers more than make up for the drawbacks such as elevated threshold voltage, lowered clear point and optical anisotropy, and enable faster response and improved voltage holding ratio relative to ordinary medium-polarity monomers.
Another purpose of the invention is to provide a liquid crystal display device employing a composition with at least one of the following properties: a large specific resistance, a high voltage holding ratio, a high clear point, a suitable optical anisotropy, a suitable dielectric anisotropy, a small viscosity, a low threshold voltage, etc., and having characteristics such as a high voltage holding ratio, a short response time, a high contrast ratio, a low power consumption and environmental friendliness.

Liquid crystal composition and liquid crystal display device thereof

JIANGSU HECHENG DISPLAY TECHNOLOGY CO., LTD.


Provided herein are, inter alia, compositions and methods for the treatment of hypercholesterolemia. The compositions include double-stranded and single-stranded RNAs capable of repressing IncRNA and concomitantly increasing LDLR activation. The compositions are useful for activating LDLR in liver cells.

Hypercholesterolemia is a condition characterized by very high levels of cholesterol in the blood, and is a major correlating factor involved in heart disease. To date, hypercholesterolemia affects approximately 1 in 500 individuals in most countries. A method to specifically reduce cholesterol in the blood in a long term and stable manner would have significant therapeutic impact.
Cholesterol is removed from the blood by the Low-density lipoprotein receptor (LDLR) expressed in the liver. There is a need in the art for compounds that de-repress LDLR expression in the liver and thereby reduce cholesterol levels in the blood. The compositions and methods provided herein cure this and other needs in the art.

Compositions and methods for the treatment of hypercholesterolemia


A rolling mill drive with spindles arranged axially slidably between pinions and work rolls. A joint of each spindle is releasably connected to the neck of at least one roll, particularly the work roll. At least the spindle joint connected to the work roll includes a coupling and uncoupling device, preferably an annular bayonet-type coupling device.

1. Field of the Invention
The present invention relates to a rolling mill drive with joint spindles arranged axially slidably between pinions and work rolls. A joint of each spindle is releasably connected to the neck of at least one roll, particularly of the work roll.
2. Description of the Related Art
In conventional rolling mill stands, the work rolls between which the material to be rolled is worked, for example, a metal strip to be cold-rolled, are driven by drive spindles which are connected to the necks of the work rolls. The drive spindles are connected to driving pinions. The pinions are driven by suitable drive motors with transmissions being arranged between the pinions and the drive motors. At the connections to the work rolls and the pinions, the drive spindles have joints, usually universal joints, for compensating angular displacements caused by varying thicknesses of the strip being rolled.
Since in normal rolling operation, the work rolls must meet high requirements and must be frequently exchanged because of the occurring wear and because of necessary adjustments to the respective rolling program, special structural provisions are made for separating the work rolls and spindles from each other. In known separating devices, the exchange of the rolls including the removal of the necks, of the sliding pieces and the pulling-off of the spindle are very cumbersome and require substantial time and operations.
U.S. Pat. No. 3,670,587 discloses a vertical rolling mill in which the rolls are exchanged by pulling two rolls apart from each other and then moving the rolls downwardly and pulling the rolls with the necks thereof out of the couplings of the drive units. However, this requires expensive and complicated arrangements for displacing and axially moving the work rolls. If the couplings of the drive units are not fixed in their position after the necks have been pulled out, the subsequent insertion of the necks of the new rolls into the coupling is very difficult.
German Offenlegungsschrift 27 33 988 discloses a drive arrangement for vertical rolling mill rolls. The drive arrangement includes a drive shaft which is releasably connected through a universal joint to the neck of a roll. An inner shaft and an outer shaft connected with the inner shaft are mounted so as to be axially displaceable. For coupling the neck of the rolling mill roll with and for uncoupling the neck of the roll from the corresponding yoke of the universal joint of the drive shaft, a positioning unit is provided which acts on the inner shaft and the outer shaft and which includes a pressure medium cylinder fastened to the outer shaft and a piston rod mounted on the inner shaft. For actuating the pressure medium cylinder, the outer shaft is moved onto the inner shaft and, thus, the shaft is shortened until the coupling yoke of the universal joint is pulled off the roll neck. This known arrangement for pulling off rolls is of complicated construction. The drive shaft is constructed in two pieces. Also, a separate device is required for fixing the shaft after the uncoupling from the roll. A separate device consists of spring arrangements, support rods, etc. which make it difficult to quickly and precisely couple an uncouple the drive shaft and the rolling mill row.
It is, therefore, the primary object of the present invention to improve the rolling mill drive of the above-described type by means of a simple, compact and very accurately adjustable structural arrangement, so that the replacement of the work rolls and the separation of the work roll and the spindle is made simpler and can be carried out more quickly than in the past. Particularly high requirements are to be met with respect to the precision of the exchange in order to reduce the loads acting on the roll bearing and the spindle joint during the roll exchange as much a possible.

Rolling mill drive with spindles releasably arranged between pinions and work rolls


The present invention comprises a carrier bag with an anchoring structure. The anchoring structure is inserted into the carrier bag and allows an umbrella to be attached to the anchoring structure. The umbrella has a collapsible canopy and can be stored in a storage compartment on the carrier bag.

1. Field of the Invention
This invention relates to an umbrella, and more particularly concerns an umbrella which can be supported by a carrier bag including a brief case, post office mail bag and other suitable bag worn by the user.
2. Description of the Prior Art
Umbrellas intended for hand-held use are generally comprised of a collapsible canopy, an elongated shaft that is usually telescopically extendable, and a holding handle disposed at the lower extremity of the shaft. Such umbrellas have long been used by persons desiring to shield themselves from the sun and rain. It is well established that, from a health standpoint, it is desirable to minimize exposure to direct sunlight.
Conventionally, umbrellas are hand carried by the person using the umbrella. Carrying an umbrella, however does not allow the free use of a person's hands to carry packages or the like, or perform other functions. It is therefore desirable to provide an improved umbrella that will allow a person using the umbrella to use their hands without being encumbered by the umbrella.
While umbrellas have heretofore been strapped to the back of a person, they are difficult to attach and the harnesses are clumsy. Further, such harnesses must be detached if the umbrella is to be hand-held, as is conventional. It is therefore desirable to provide an umbrella which can be worn, if desired, but which includes structure which allows the umbrella to be worn or hand-held, as desired, while still being convenient to use and conveniently stored.
Examples of such back-mounted umbrellas are disclosed in U.S. Pat. Nos. D330,455; D345,856; D361,654; 3,892,251 and 4,188,965. In general, such back-mounted umbrellas involve a harness which either secures an umbrella of usual construction having a bottom handle, or secures a specially constructed umbrella having a straight shaft that removably inserts into a holding structure associated with the harness.
A common shortcoming of prior back-mounted umbrellas is that the umbrella tends to rotate within the holding structure, particularly in strong winds. Also, tilting movements in both the path of the person's walking movement and in the lateral or transverse direction are difficult to control. When a specialized harness is employed, it is difficult to emplace and is restrictive, and serves no other useful purpose.
It is accordingly an object of the present invention to provide an umbrella and frame support combination wherein the frame provides support for the umbrella.
It is a further object of this invention to provide the combination of the foregoing object wherein the umbrella is easily attached to and removed from a receiver attached to the frame support.
It is another object of the present invention to provide the combination of the aforesaid nature wherein the umbrella, in its deployed, open state is stabilized with respect to rotative and tilting movements.
It is yet another object of this invention to provide the combination of the aforesaid nature wherein said carrier bag contains means for securing said umbrella in its collapsed, storage state.
It is a still further object of the present invention to provide the combination of the aforesaid nature wherein the separate functionality of umbrella and bag remains unimpaired.
These objects and other objects and advantages of the invention will be apparent from the following description.


A vehicle rear body structure includes rear floor panels, rear wheel housings, and rear side extensions. The rear side extensions each have a first joined portion that is joined to a breadthways outer end of each of the rear floor panels, a second joined portion that is joined to an rear end of each of the rear wheel housings, a side portion that is an uprising slanted portion extending from the rear end of the first joined portion to the second joined portion, a surface portion surrounded by the first joined portion, the second joined portion, and the side portion, and an extending portion joined to a flange portion of a rear pillar, wherein the side portion is configured to have higher stiffness or strength than at least the surface portion.

A vehicle rear body structure according to conventional technologies is shown in FIG. 7 (see Japanese Unexamined Patent Application Publication No. 2002-29453). FIG. 7A is a perspective view of a joined portion between a rear wheel housing and a rear floor panel. FIG. 7B is a perspective view of a rear floor side extension. FIG. 7C is a longitudinal sectional view taken along line VIIB-VIIB of FIG. 7A.
As shown in FIG. 7, in a vehicle rear body structure disclosed in Japanese Unexamined Patent Application Publication No. 2002-29453, a rear floor side extension 1 is longitudinally and vertically enlarged and joined at its front edge 1a to a joining area of a mating flange 3 located at the rear side of a rear wheel housing outer panel 2a. Then, the rear floor side extension 1 thus mounted to the rear body side is joined breadthways to an upstanding wall 6a of the rear floor side panel 6 through a draught opening 5 (see FIG. 7C) of a rear fender panel 4 when installed to a rear floor assembly. The vehicle rear body structure disclosed in Japanese Unexamined Patent Application Publication No. 2002-29453 allows the use of an enlarged rear floor side extension without posing any problems in joining the rear floor side extension, thereby enhancing the reinforcement of the rear side section.
A joined portion A (see FIG. 7A) between a rear floor panel (rear floor side panel 6) and the rear side extension 1 is subjected to vertical, longitudinal, and lateral loads from a suspension input point (rear wheel housing 2). In addition, the joined portion A constitutes a lower end of a vehicle rear end and is located at a side end corner, greatly affecting the stiffness of the vehicle rear section.
With this in mind, in a vehicle rear body structure disclosed in Japanese Unexamined Patent Application Publication No. 2002-29453, a slanted side H on the top end of a surface portion M formed between the joined portion A and a joined portion B (joined portion between the rear floor side extension 1 and the rear wheel housing 2) does not extend to the joined portion A from the joined portion B (see FIG. 7A), and thus contributes less to the stiffness of the vehicle rear section.
Also, in a vehicle rear body structure disclosed in Japanese Unexamined Patent Application Publication No. 2002-29453, the joined portion A and a joined portion C (joined portion between the rear floor side extension 1 and a body side panel) are vertically spaced apart from each other (see FIG. 7A) with only one plate member provided between the joined portion A and the joined portion C (see FIG. 7C), and thus contribute less to the stiffness of the vehicle rear section.
Furthermore, in a vehicle rear body structure disclosed in Japanese Unexamined Patent Application Publication No. 2002-29453, the rear floor panel 7 and the rear wheel housing 2 are joined to each other with two components, including the rear floor side panel 6 and the rear floor side extension 1, therebetween. A greater number of joined portions between such two components results in a lower contribution to the stiffness of the vehicle rear section.