An improvement to a dual-modulation line-locking device for wavelength modulation spectroscopy employing a lowpass filter to generate a nonnormalized error signal and a bandpass filter and RMS-to-DC converter to generate a centering signal. When the error signal is approximately zero and the centering signal is large, the wavelength is coincident with the center of the absorption feature of the sample.

1. Field of the Invention (Technical Field)
The present invention relates to wavelength modulation spectroscopy.
2. Background Art
Dual-modulation line-locking, described in D. Bomse, Applied Optics 30:2922-4 (1991) and in the parent applications to the present application, listed above, is a useful application of optical spectroscopy for continuous monitoring of a selected species. The technique yields high sensitivity measurements of an optical absorbance generated by the target species while also providing simultaneous wavelength stabilization of a spectroscopic light source. In particular, dual-modulation line-locking improves wavelength modulation spectroscopy, which is a spectroscopic method that is easily implemented with wavelength tunable light sources such as diode lasers, by removing baseline fluctuations that add error to the absorbance measurements.
In Bomse's original dual-modulation line-locking method, the wavelength of a light source is modulated at two frequencies. Typically, a beam splitter diverts part of the light through a sample region and onto a detector such as a photodiode; the remainder of the light passes through a reference cell filled with an amount of the target species and then impinges on another detector. Optical absorption by the species in the sample and reference paths converts some of the wavelength modulation into synchronous amplitude modulations of the light, with the magnitude of the induced amplitude modulations being proportional to the size of the absorbances. The magnitude of the absorbance can be directly related to the absolute concentration of the absorbing species. Output from the sample leg detector is processed by two sequential demodulations to provide a signal that is proportional to the sample leg optical absorbance, hence proportional to the amount of target species within the path. One advantage of the sequential demodulation is that the absorbance measurement is free of baseline fluctuations. Output from the reference leg detector is also processed by two sequential demodulations, but the frequencies of the reference waveforms used for the demodulations are selected such that the demodulated spectral waveform can be used as a feedback signal for wavelength stabilization of the light source. Ideally, the reference leg signal is zero when the light source wavelength is coincident with the center wavelength of the absorption feature, and the signal varies linearly with small displacements from the center wavelength. This use of an optical absorbance for wavelength stabilization is generally known as line-locking and can be implemented using wavelength modulation spectroscopy as well as frequency modulation spectroscopy.
Two problems may arise, however, when implementing line-locking. The first occurs because the line-locking feedback signal can be approximately zero when the spectroscopic source wavelength is coincident with the center of the reference absorption feature or when the source wavelength is far removed from line center. The conventional line-locking signal cannot be used to distinguish between these two cases. The other problem arises when the amount of absorber material in the reference path changes. This introduces uncertainty into the amount of wavelength correction that needs to be applied in response to a given feedback signal. In other words, changing the amount of reference absorber material varies the gain of the feedback loop and can cause instabilities in the line-locking.
FIG. 3 is a schematic diagram of an undisclosed method (developed by the present inventors) that uses a second demodulator to provide a signal proportional to the optical absorbance within the reference leg optical path. The current applied to a diode laser 126' such as a Lasertron model QLM5S890-002 is modulated sinusoidally at two frequencies simultaneously, .OMEGA.=1 MHz and .omega.=10 kHz. It is well known that changing the current applied to a diode laser is a simple method for changing the wavelength of the laser light. The 1 MHz waveform is obtained by applying the output from a 3 MHz TTL oscillator 118' such as a Dale model X0-43B to a down counter 122' such as a Texas Instruments 74HC160N integrated circuit configured as a divide-by-three circuit component. Output from the counter is bandpass filtered 132' using a device similar to a TTE, Inc. series KC4-1M bandpass filter to produce a 1 MHz sine wave that is used as the first modulation frequency. The 10 kHz modulation waveform is supplied by a function generator 120' such as a Stanford Research Systems model DS345 function generator. The DC portion of the laser current is supplied by a current source such as an ILX model 3722b diode laser controller.
A beamsplitter 128' divides the laser beam into a sample leg portion 130' used for determining the absorbance of an unknown amount of the target species and a reference leg portion used for line-locking. The latter beam passes through a reference cell 138' filled with some of the target species and onto a photodiode detector 140' such as an Epitaxx ETX1000T InGaAs photodiode. The signal produced by the photodiode is demodulated using demodulator #1 142' such as a Mini-Circuits SRA-6 mixer; the local oscillator for the demodulator is supplied by the 3 MHz oscillator 118'.
Output from demodulator #1 is applied to a lowpass filter 144'. The lowpass filter is a device similar to a TTE, Inc. LC7-series filter and removes AC signal components at 1 MHz and 10 kHz (frequencies .OMEGA. and .omega.) and their harmonics. Output from the lowpass filter provides the unnormalized error signal that is used for laser wavelength stabilization.
Output from demodulator #1 is also applied to demodulator #2 150 which uses frequency .omega. from source 120' as its local oscillator. Demodulator#2 150 is a device similar to Analog Devices AD630 integrated circuit. It produces a voltage proportional to the amplitude of the 10 kHz AC signal that is present on the output of demodulator #1 142'. When the laser wavelength is coincident with the center of the optical absorbance and the phase of the local oscillator is properly adjusted, the output of demodulator #2 150 is directly proportional to the optical absorbance in the reference path. Dividing the error signal obtained at the lowpass filter by the absorbance signal yields a normalized error signal that provides improved reliability for laser wavelength stabilization.
The present invention improves on dual-modulation line-locking by processing the line-locking signal to 1) verify that the light source wavelength is coincident with the absorption line center, and 2) maintain constant gain in the wavelength stabilization feedback loop.

Dual-modulation laser line-locking for wavelength modulation spectroscopy


The present disclosure relates to a method for improving an estimation process, comprising providing an image; detecting a failure area within said image to obtain a failure area map; obtaining a motion or disparity estimation map containing estimation vectors determined in an estimation process; providing a local direction model, LDM, map comprising LDM vectors determined on the basis of said estimated vectors and said detected failure area, and adjusting said estimation process dependent on the local direction model map.

Field of the Disclosure
The present disclosure relates to a method for improving an estimation process, particularly a motion estimation process. The disclosure also relates to a device for providing an improved disparity or motion estimation map, as well as a computer program and a non-transitory computer-readable recording medium.
Description of Related Art
Estimation processes, like motion estimation or disparity estimation, are widely used in image-processing applications. In particular, frame rate up-conversion and the required image interpolation is based on motion estimation results. Some of the best motion estimation algorithms are based on recursive search block matching. The recursive estimation algorithm evaluates a set of candidate vectors which are derived from spatial or temporal predictor positions, which are partially modified based on particular schemes to allow for motion changes, by a matching criterion. However, these recursive search motion algorithms usually have problems with flat or low contrast image contents. One of the reasons is a so-called penalization system used in recursive search motion vector estimation algorithms. The penalization system is for example used to penalize local motion vector changes. The idea behind is that motion vectors inside an object within an image should have the same or at least similar motion vectors. Or in other words, objects are larger than blocks and objects have inertia. Therefore vectors should be similar among blocks in objects.
It has been recognized that such recursive search motion vector estimation algorithms using penalization systems have problems in gaining accurate estimation vectors for flat areas. For example it maybe that a large flat area is assigned with a constant motion vector instead of having a smooth gradient vector field with the result of annoying local judder artefacts in an interpolated image.
The "background" description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventor(s), to the extent it is described in this background section, as well as aspects of the description which may not otherwise qualify as prior art at the time of filing, are neither expressly or impliedly admitted as prior art against the present invention.

Local detection model (LDM) for recursive motion estimation


An optical arrangement includes a transmissive or reflective substrate having a first surface on which a multi-layer antireflection stack is formed. The antireflection stack is protected by a fluorocarbon lubricating layer that reduces the surface energy of the exposed surface to less than 40 dynes/cm, and preferably less than 20 dynes/cm. The fluorocarbon lubricating layer and a silane adhesion promotion layer form a durable topcoat having desired mechanical and optical characteristics. The preferred material for forming the lubricating layer is a fluoropolymer sold by 3M Company under the federally registered trademark FLUORAD.

Coatings are applied to light transmissive or reflective members in order to impart desired optical properties to the members. For example, one or more coatings may be applied to a screen of a computer monitor in order to provide polarization or to reduce reflection. A cathode ray tube (CRT) may be surface coated with an antireflection layer having an optical thickness of approximately one-quarter of the center wavelength of light that is to be reflected. The antireflective coating may be an organic material, such as a polymer, or an inorganic material, such as a metal fluoride, metal oxide, or metal nitride. Often, the antireflective coating is a multi-layer stack.
Obtaining the desired optical properties is not isolated from other concerns. Coating a light transmissive member should not render the coated surface susceptible to chemical or mechanical damage. One approach to providing a coating having the required properties is to select a single material for forming a layer that reaches acceptable levels of antireflectivity, mechanical strength and chemical resistance. U.S. Pat. No. 5,281,893 to Matsuda et al. describes an optical film for application to a display screen of a CRT or liquid crystal display (LCD). The optical film is described as having a reduced external light reflection, a high mechanical strength and an increased resistance to damage caused by humidity. While the single-layer approach provides advantages with respect to ease of fabrication, this approach necessarily requires that tradeoffs be made among the various properties.
The more common approach is to utilize a multi-layer assembly. U.S. Pat. No. 5,170,291 to Szczyrbowski et al. describes a four-layer system having alternately high and low refractive indices in order to achieve a high antireflection effect. However, the exposed outermost layer remains susceptible to damage caused by contact with an object or a chemical. Ideally, the outermost layer is resistant to attack by common cleaners and solvents, is scratch-resistant, is not stained by water or oils, and allows easy removal of dust and other particulate matter. At the same time, the layer should not adversely affect the optical properties of the coated assembly.
U.S. Pat. No. 5,476,717 to Floch describes a multi-layer assembly for a transparent substrate. An adhesion promotion layer formed of a material selected from silanes is formed on the substrate. An antireflection coating formed from colloids of silica in a polysiloxane binder is then formed on the adhesion promoter layer. Then, a coupling agent layer of a material selected from silazanes is applied. Finally, an anti-abrasion layer of a fluorinated polymer is formed to reduce the mechanical vulnerability of the assembly. The anti-abrasion layer identified in the patent is a derivative of polytetrafluoroethylene (PTFE), which is sold under the federally registered trademark TEFLON AF and marketed by duPont de Nemours. While the anti-abrasion layer provides a number of advantages over prior art assemblies, one disadvantage is that the TEFLON AF on the silazane material must be raised to a relatively high temperature. The Floch patent identifies a final heating stage at a temperature between 110.degree. and 120.degree. C. in order to evaporate the residue solvent. Another disadvantage is that the coating may be relatively easily damaged by normal use, for example, in computer display applications.
A parameter that is used to characterize properties of a surface is contact angle, i.e., the angle formed between the plane of the surface and the tangent to a droplet on the surface. The measure of the contact angle is an indication of surface energy and may be used to characterize the wetability, oil resistance (e.g., anti-smudge) and the lubricating effects of a coating on a substrate.
What is needed is a light transmissive assembly in which tradeoffs between optical and mechanical properties are minimal and a protective layer is formed as the outermost layer in a cost efficient manner that does not jeopardize the structural integrity of previously formed layers. More specifically, what is needed is a topcoat that has a high contact angle, that maintains a high contact angle after rubbing, and that is formed at a sufficiently low temperature to not jeopardize either a substrate or an intermediate layer between the substrate and the topcoat.

Multi-layer topcoat for an optical member


The invention herein described consists of an algorithm, which performs an end-to-end estimation of the bandwidth available in an end-to-end connection established between a server and a client via a packet switching network such as the Internet Protocol Network (IP). This algorithm is used to properly regulate the input rate at the send side. Typical applications are delivering best effort traffic over TCP, or audio and video traffic over RTP/UDP. The invention is particularly effective over wireless Internet and can be used in a content delivery system to dynamically choose the best server between a set of servers to satisfy the request of a client, or to select the best route in a content deliver or global hosting system.

1. Technical Field
This invention relates generally to efficient communication over packet switching networks. More particularly, the invention relates to a novel method for performing an end-to-end estimation of available bandwidth and a congestion control in packet networks such as the Internet. The invention addresses the issues of improving the efficiency in transferring data, audio and video over of the wireline and wireless Internet.
2. Description of the Related Art
The Internet Protocol connects all variety of different networks. An IP network implements a simple store-and-forward service. Over the IP network there are two transport protocol: the Transmission Control Protocol (TCP) and the User Datagram Protocol (UDP). The TCP is a sophisticated and complex protocol that offers a reliable, connection-oriented, end-to-end byte-stream service. It contains sophisticated algorithms of flow and congestion control in order to manage resource sharing and avoid congestion phenomena. Congestion control functions were introduced into the TCP in the late 1980s after the TCP/IP had become operational, and the network was suffering from congestion collapse. TCP congestion control has been introduced and described by V. Jacobson in his papers. Van Jacobson's seminal paper defines an additive increase/multiplicative decrease algorithm for throttling the size of the congestion window. The key idea is to probe the network capacity by increasing the load until packet loss is experienced. When a loss is experienced, the window size is reduced. More precisely, first cwnd is increased until packet losses are experienced and then it is rapidly decreased. The increasing process goes through two phases called slow start and congestion avoidance. During the slow start phase cwnd is exponentially increased until the slow start threshold (ssthresh) value is reached. This phase is intended to quickly grab available bandwidth. After the ssthresh value is reached, the cwnd is linearly increased to gently probe for extra available bandwidth. This phase is called congestion avoidance. At some point the TCP connection starts to lose packets. After a timeout is experienced, the window is drastically reduced to one and the slow start/congestion avoidance cycle repeats. This behavior is known as TCP Tahoe. Since during the slow start phase the network can be strongly underutilized, two other algorithms, called fast retransmit and fast recovery, were introduced to minimize the number of timeouts. The implementation of these algorithms provides what is currently called TCP Reno. Fast retransmit and fast recovery are both triggered after the sender receives three DUPACKs. The algorithm of fast retransmit sends again the packet that was acknowledged three times. The algorithm of fast recovery reduces the congestion window to half and enters into congestion avoidance phase. After a time out, the Congestion window is reduced to one.
Today TCP Reno is the more widely version employed. It is used in the leading Unix, Linux TCP protocol suite or in the Microsoft Windows TCP® protocol suite.
TCP was originally designed to provide reliable data delivery over conventional wireline networks for a limited range of transmission rates and propagation delays. Nowadays, communication paths with ever-larger bandwidth×delay product, wireless links, quality of service (QoS) requirements for interactive communication are all shifting the domain for which TCP was originally engineered.
We list here main modifications proposed for TCP Reno. TCP with selective acknowledgments (TCP SACK) introduces a more refined algorithm for acknowledging data TCP New Reno introduces a algorithm for recovering from many losses in a window of data.
A new congestion control algorithm is known as TCP Vegas. It throttles the congestion window based on the difference between the Actual Rate and the Expected rate. This algorithm has never been deployed in the TCP protocol suite of Microsoft or other commercial operating systems or in the Unix or Linux operating systems.
Today the TCP has a major performance problem over unreliable links such as wireless links that are often characterized by sporadic high-bit error rates, and intermittent connectivity due to handoffs. In fact, a loss due to an unreliable link is misinterpreted as a symptom of congestion by current TCP schemes and thus leads to an unnecessary shrinking of the control windows (i.e. the slow start and congestion window) with a consequent throughput reduction. It is well-know that TCP experiences a very low performance over wireless links such as in the GSM, GPRS, 3G, 4G, or UMTS systems. Analogously, it is also very well-known that TCP is not able to use the bandwidth of satellite links, which are characterized by large delays and random loss.
Recently, several schemes have been proposed to mitigate the negative effect on TCP performance of sporadic loss due to wireless links. These schemes can be classified into three groups: end-to-end proposals, split connection proposals and link layer proposal. End-to-end proposals aim at improving the performance of TCP using some form of selective acknowledgment (SACKs) to recover from multiple packet loss in a window of data. They also try to have the sender distinguish between loss due to congestion and other forms of losses using an Explicit Loss Notification (ELN) algorithm. Split connection approaches hide the wireless link by terminating the TCP connection at the base station. Such schemes use a separate connection between the base station and the destination host and can use techniques other than TCP to perform well over wireless links. Examples of these schemes are: Indirect TCP or Snoop protocol. Link layer proposals attempt to hide loss due to wireless links using local retransmissions and perhaps forward error correction over the wireless link. Examples of link layer protocols are forward error correction (FEC) and automatic repeat request (ARQ). Digital cellular systems, such as TDMA or CDMA, use ARQ protocols.
All solutions we have briefly described suffer serious drawbacks. In fact, in one case they violate the end-to-end paradigm, thus requiring complex implementation, or in the other case, they do not offer a remarkable throughput increment.
Another known problem of TCP is that it experiences a very low performance over connection with asymmetric bandwidth. These problems arise in several access networks, including bandwidth-asymmetric networks and packet radio subnetworks. In these cases, the TCP performance degrades significantly because of imperfection and variability in the ACK feedback from the receiver to the sender.
The present invention solves the problem of improving the fairness of TCP, the throughput of TCP over wireless connection and over connection with asymmetric bandwidth using an end-to-end approach. The present invention solves also other problems in real-time streaming of audio and video sources that are associated with prior art.

End-to-end bandwidth estimation for congestion control in packet switching networks


A signal capture element for providing a first pre-charged logic level as first and second interim address portion signals during a pre-charged period and outputting during an evaluate period an address portion logic level as the first interim address portion signal and an inverted address portion logic level as the second interim address portion signal. First and second address portion signals are derivable respectively from first and second interim address portion signals. An inverter circuit for outputting to an address decoder during a pre-charged period a second pre-charged logic level as the first and second address portion signals. The inverter circuit having transfer characteristics that maintain voltage levels such that the first and second address portion signals are interpreted to be at the second pre-charged logic level despite the first or second interim address portion signal failing to transition to a valid logic level during the evaluate period.

1. Field of the Invention
The present invention relates to address decoding. Embodiments of the present invention relate to a circuit for driving an address decoder which is tolerant of metastable signals.
2. Description of the Prior Art
In a data processing apparatus, such as a pipelined data processing apparatus, a series of serially connected stages are formed. The processing circuitry of each processing stage is responsive to input signals received from preceding processing stages in the pipeline or from elsewhere and generates output signals. Between each stage of the pipeline is provided a signal capture element such as a latch or a sense amplifier into which one or more signal values are stored. The latch receives the input signals, stores the input signal value and presents this stored value on its output in response to a clock signal provided thereto.
In order for the latch to reliably store the input signals provided at its input, it is necessary for the input signal to achieve a particular voltage level representative of a value to be stored at a time which is no later than a predetermined period prior to the clock signal being provided to the latch (known as the set-up period) and for this voltage level to be maintained for a predetermined period following the provision of the clock signal (known as the hold period).
However, in the event that the input signals provided to the latch transitions in the set-up or hold period then metastability can occur. A consequence of this is that the output provided by the latch does not make a clean transition between logic levels but instead achieves a value somewhere therebetween, known as a metastable voltage. Typically, the metastable voltage is a level approximately midway between the valid logic level voltages.
Metastability is typically avoided by ensuring that the input signals only transition outside of the set-up and hold periods. This ensures that the input signals can be cleanly sampled by the latch.
However, in order to attempt to improve the performance of data processing apparatuses, it is known to increase the speed at which the processing stages are driven by increasing the clock rate until the slowest processing stage in the pipelined processor is unable to keep pace. Also, in situations where it is desired to reduce the power consumption of the data processing apparatus, it is known to reduce the operating voltage up to the point at which the slowest processing stage is no longer to keep pace. In both of these situations it is no longer possible to ensure that the signal transitions do not occur within the set-up and hold periods and metastability can occur.
A consequence of such metastability is that erroneous data values may be generated. In extreme cases, erroneous control signals may also be generated which may cause valid data to be corrupted. For example, should metastability occur whilst performing an access to a memory then a corruption of the internal state of the memory may occur.
In order to avoid metastability causing corruption of the internal state of the RAM, it is known to place write accesses to the RAM in a write queue. The write accesses are then only allowed to occur once system level validation process has confirmed that the signals associated with the write access are valid and that no metastability in those signals exists.
It is desired to provide techniques for accessing memory which are tolerant of metastable signals.

The Regents of the University of Michigan


A light guide assembly, a backlight module and a liquid crystal display (LCD) are provided. The backlight module includes a back plate light guide plate, an adhesive member and a light source. The light guide plate is disposed on the back plate and includes a first optical surface, a second optical surface and a light-incident surface. The first optical surface is opposite to the second optical surface. The light-incident surface connects the first optical surface and the second optical surface. The first optical surface or the second optical surface of the light guide plate is set with recess. The adhesive member is disposed in the recess to adhere the light guide plate to the back plate. The light source is disposed on the back plate and emits light toward the light guide plate.

1. Field of Invention
The present invention relates to a light source module. More particularly, the present invention relates to a light guide assembly, a backlight module and a liquid crystal display.
2. Description of Related Art
A backlight module is one of the critical components of a liquid crystal display (LCD). Currently, liquid crystal displays (LCDs) have been widely used in portable electronic products with high-growth potentials such as cell phones, notebook computers, digital cameras, etc. With the trend of portable electronic products toward thinness and lightweight, how to reduce the thickness of the backlight module is an object to which people in the related industries are devoted.
Referring to FIG. 1, FIG. 1 is a schematic cross-sectional view of a conventional backlight module 100. In the design of the conventional backlight module 100, for securing a light guide plate 110, a double faced adhesive tape 120 is disposed on a bottom surface of a light guide plate 110 to attach the light guide plate 110 to a back plate 130. However, because the double faced adhesive tape 120 itself has a thickness, this securing method using the double faced adhesive tape 120 is disadvantageous for thinning the backlight module and the LCD.
Hence, there is a need to provide a light guide assembly, a backlight module and a LCD to meet the trend of portable electronic products.

Light guide assembly, backlight module and liquid crystal display


Time-based servopositioning systems, methods, formats, and data recording media used in association with the same, employing bands of signals that differ from each other in the polarity of the servo signal, or the orientation of the servo signal, or the pattern width of the servo signal.

Modern data storage systems use servopositioning (or "servo") systems to guide their recording and playback components with respect to a recording medium, and thus enable high track density, which increases data storage capacity. Errors in the ability to follow the servopositioning signals on the medium can cause unacceptable reductions in storage capacity, recording/playback rates, and other parameters that are important to consumers (and thus to system manufacturers).
One type of servo patterns or formats for linear magnetic tape recording systems employs so-called time-based servo techniques, examples of which are disclosed in U.S. Pat. Nos. 5,689,384; 5,930,065; and 6,021,013 (all of which are incorporated by reference in their entireties). Commercial magnetic tape drives such as the IBM model 3570 and drives known under the names "Ultrium" and "Accelis," as described by the Linear Tape Open (LTO) consortium, use time-based servopositioning systems.
The advantages of time-based servo systems include very wide dynamic range; inherent track identification; low DC centerline error; and the ability to qualify position error signal (PES) validity by the amplitude of the servo signal. Disadvantages include extreme sensitivity to tape speed during writing; sensitivity to high frequency speed error during reading; and poor scalability to very small track pitches.

Band identification in time-based servopositioning formats


The invention is a process of using, as a reducing agent, a 12CaO.7Al2O3 electride containing electrons in a number of 1019 or more and 2.3×1021 cm−3 or less in its cages to subject a carbonyl compound to reductive coupling in a solvent, thereby synthesizing a diol or polydiol. The invention is also a process of reducing a ketone compound in a solvent, thereby synthesizing a secondary alcohol or diketone compound. According to the process of the invention, it is possible to synthesize a diol or polydiol, or a secondary alcohol or diketone compound through simple operations in a short period without using an expensive and harmful metal hydride or metal salt nor limiting the atmosphere for the synthesis to an inert gas atmosphere as in conventional processes.

About the synthesis of a diol by reductive coupling reaction of a carbonyl compound, it is known that a metal compound or metal salt, such as magnesium amalgam, aluminum amalgam, samarium iodide or vanadium chloride, functions as a reducing agent (Non-Patent Document 1).
However, the metal compound or metal salt is expensive and harmful, and further it is necessary to conduct the reaction in a water-free organic solvent in the atmosphere of an inert gas. For this reason, the reaction using the metal compound or metal salt was very unsatisfactory for a simple and environment-friendly reducing process. Known is also a process of conducting the reaction in an organic solvent, using metallic calcium as a reducing agent (Patent Document 1).
Secondary alcohols and diketones containing an aryl group and/or an alkyl group are widely used as intermediate compounds for medical supplies, colorants, and others. It is necessary to synthesize these compounds by an environment-friendly and safe process.
For the synthesis of a secondary alcohol through reductive reaction of a ketone compound, it is known that a metal hydride containing boron or aluminum, such as NaBH4, LiBH4, LiAlH4 or Zn (BH4)2, functions as a reducing agent. However, the metal hydride is expensive and harmful, and further these metal hydride has a drawback that the metal hydride can be used only in a dry atmosphere and a dry solvent containing no water since the metal hydride dislikes the presence of water extremely. Besides, known is a process of causing polymethylhydrosiloxane to react with a ketone in the presence of a catalytic amount of tetrabutylammonium fluoride to reduce the carbonyl group of the ketone, thereby yielding an alcohol compound (Patent Document 2).
In 1970, H. B. Bartl et al. disclosed that the crystal of 12CaO.7Al2O3 (referred to as "C12A7") has a unique crystal structure that two out of 66 oxygen ions present in a cell containing two molecules thereof undergo clathration, as "free oxygen", into spaces in cages present in the crystal (Non-Patent Document 2). Thereafter, it was made evident that the free oxygen ions can be substituted with various anions. In particular, when C12A7 is held in an intensely reducing atmosphere, entire free oxygen can be substituted with electrons. C12A7:e−, wherein free oxygen is substituted with electrons, can be regarded as an electride.
Electride compounds are based on an idea suggested unprecedentedly by J. L. Dye (Non-Patent Document 3). No electride compounds were realized until a compound containing a crown ether as a cation and an electron as an anion, and other compounds were produced. It is known that an electride exhibits electroconductivity through the hopping of an electron contained as an anion. Thereafter, some organic electrides were found out. However, all of these compounds are stable only at a temperature as low as about −100° C. or lower, and are remarkably unstable compounds reactive with air or water.
The inventors filed, as a patent application, an invention relating to electroconductive C12A7 and analogue compounds thereof, and a production process thereof (Patent Document 3). The inventors found out that a C12A7 compound having an electroconductivity of 103 S/cm or less is yielded by annealing C12A7 monocrystal at high temperature in a vapor of an alkali metal or alkaline earth metal, ion-implanting an inactive ion such as Ar into C12A7 monocrystal, or solidifying C12A7 monocrystal directly from a melt in a reducing atmosphere. An invention relating thereto was filed as a patent application (Patent Document 4). Furthermore, the inventors succeeded in yielding C12A7 exhibiting metallic electroconductivity by annealing C12A7 monocrystal in a vapor of metallic titanium (Ti), and then filed, as a patent application, the production process of C12A7, and a usage thereof as an electron-releasing material (Patent Document 5).
These C12A7 compounds, which exhibit a good electroconductivity, are compounds wherein all of free oxygen ions are substituted with electrons, are each substantially represented by [Ca24Al28O64]4+ (4e−), and can be regarded as inorganic electride compounds (Non-Patent Document 4).
Electrons undergoing clathration into C12A7 electrides are loosely bonded to cations, so that the electrons can be taken into the outside by applying an electric field thereto or by a chemical means. It appears that the electrons taken into the outside can be used in reductive reaction. However, unknown is an example in which electrons undergoing clathration into a C12A7 electride are applied directly to reductive reaction.
Non-Patent Document 1: G. M. Robertson, Comprehensive Organic Synthesis 3, 563 (1991)
Non-Patent Document 2: H. B. Bartl, T, Scheller and N. Jarhrb, Mineral Monatsh, 1970, 35, 547-552
Non-Patent Document 3: F. J. Tehan, B. L. Barrett, J. L. Dye, J. Am. Chem. Society, 96, 7203-7208 (1974)
Non-Patent Document 4: S. Matsuishi, Y. Toda, M. Miyakawa, K. Hayashi, T. Kamiya, M, Hirano, I. Tanaka and H. Hosono, Science, 301, 626-629 (2003)
Patent Document 1: Japanese Patent Application Laid-Open (JP-A) No. 2002-265391
Patent Document 2: JP-A No. 10-87530
Patent Document 3: WO 2005/000741A1
Patent Document 4: JP-A No. 2004-26608
Patent Document 5: WO 2007/060890A1

Method of producing diol, polydiol, secondary alcohol or diketone compound


Embodiments of the invention provide a thin film transistor, an array substrate and a manufacturing method thereof, and a display panel. The thin film transistor comprises: an active layer pattern, a source electrode, a drain electrode and a gate electrode. The gate electrode is positioned above the active layer pattern, the source electrode is connected with the active layer pattern, the drain electrode is connected with the active layer pattern, and the source electrode and the drain electrode are disposed in an adjacent layer of the active layer pattern.

Embodiments of the invention relate to a thin film transistor, an array substrate, a manufacturing method of the array substrate, and a display panel.
Array substrate is an important component of a display panel. At present, low temperature poly-silicon (LTPS) material may be used to manufacture the array substrate. Due to problems in thermal process of LTPS, the array substrate generally adopts a top gate structure. FIG. 6 is a structural schematic view of a conventional array substrate. As shown in FIG. 6, the conventional array substrate comprises a substrate 17, and gate lines (not shown) and data lines 14 located on the array substrate. The gate lines and the data lines 14 cross with each other to define pixel regions. In each pixel region, there are formed a pixel electrode 18, a thin film transistor and a common electrode 19. The common electrode 19 forms a fringe electric field with the pixel electrode 18. The thin film transistor comprises an active layer pattern 10, a source electrode 11, a drain electrode 12 and a gate electrode 13. A buffer layer 21 is formed on the substrate 17. The active layer pattern 10 is formed on the buffer layer 21. The active layer pattern 10 comprises a channel region 10a, a lightly doped drain (LDD) region 10b, a source region 10c and a drain region 10d. The source region 10c and the drain region 10d are regions doped with impurity at a high concentration. The LDD region 10b is a region doped with impurity at a low concentration. A third insulation layer 22 is formed on the active layer pattern 10. The gate line and the gate electrode 13 are formed on the third insulation layer 22 at the same time, the gate line and the gate electrode 13 are connected with each other, and the gate electrode 13 is provided above the active layer pattern 10. A fourth insulation layer 23 is formed on the gate electrode 13. The pixel electrode 18 is formed on the fourth insulation layer 23. A first via hole 24 is formed in the third insulation layer 22 and the fourth insulation layer 23 above the active layer pattern 10, and the source electrode 11 is filled in the first via hole 24 to be connected with the active layer pattern 10. The source electrode 11 is also connected with the data line 14. A second via hole 25 is further formed in the third insulation layer 22 and the fourth insulation layer 23 above the active layer pattern 10, and the drain electrode 12 is filled in the second via hole 25 to be connected with the active layer pattern 10. The drain electrode 12 is partially provided on the pixel electrode 18 to be connected with the pixel electrode 18. A protection layer 26 is formed on the source electrode 11 and the drain electrode 12, and the common electrode 19 is formed on the protection layer 26.
As described above, in the conventional array substrate, the source electrode and the active layer pattern of the thin film transistor are connected with each other by via hole, and the drain electrode and the active layer pattern are also connected with each other by via hole. However, when via holes are formed in the pixel region, the aperture ratio of the pixel region is reduced.

Thin film transistor, array substrate and manufacturing method thereof, and display panel

CHENGDU BOE OPTOELECTRONICS TECHNOLOGY CO., LTD.


An adjustable wake-forming apparatus attachable to a boat stern providing means for generating waves of a particular form for water sport activities. The attachment is comprised of a pair of blades fastened to the transom by a plurality of struts. The present invention provides for the use of the wave maker on boats having either an inboard or outboard engine. Each of the provided designs places the blades in a spaced away relationship to the engine propeller. Operatively, the blades have a top edge and curvilinearly diverging bottom edge with anterior and posterior ends linearly skewed causing a plow-like movement through the water.

1. Field of the Invention
The present invention relates generally to boats and, more specifically, to an adjustable wake-forming apparatus attachable to a boat stern providing means for generating waves of a particular form for water sport activities. The attachment is comprised of a pair of blades fastened to the transom by a plurality of struts. The present invention provides for the use of the wave maker on boats having either an inboard or outboard engine.
Each of the provided designs places the blades in a spaced away relationship to the engine propeller. Operatively, the blades have a top edge and curvilinearly diverging bottom edge with anterior and posterior ends linearly skewed causing a plow-like movement through the water.
The inboard engine design of the wavemaker is comprised of anteriorly hinged blades with struts serving as means for attachment to the boat stern, as well as means for effecting a wave form. A posteriorly fixed strut extends between the blades whereby the fore to aft blade skew angle can be varied. Extending from the opposing boat stern sides is a pair of struts, one over the other with the top ones incorporating means for varying the length while the bottom ones having a fixed length provide means for changing the blade pitch. Also extending between the boat stern and anterior blade top is a strut also incorporating length adjusting means whereby the blade depth can be changed.
The outboard engine wavemaker design is comprised of blades positioned on each side of the engine with struts serving as means for attachment, as well as means for effecting a wave form. A posteriorly fixed strut extends between the blades whereby the fore and aft blade skew angle can be varied. Mounted on opposing boat stern sides is a bracket having a threaded post with a pair of struts of fixed length mounted thereon, one over the other providing means for adjusting the depth of the blade relative to the water.
2. Description of the Prior Art
There are other devices designed for effecting a wave pattern. Typical of these is U.S. Pat. No. 818,887 issued to Hoeglauer on Apr. 24, 1906.
Another patent was issued to Bosnich on Apr. 28, 1970 as U.S. Pat. No. 3,508,511. Yet another U.S. Pat. No. 3,670,685 was issued to Milessa on Jun. 20, 1972 and still yet another was issued on Nov. 12, 1974 to Kaufer as U.S. Pat. No. 3,847,104.
Another patent was issued to Wordell, Sr. on Feb. 22, 1977 as U.S. Pat. No. 4,008,677. Yet another U.S. Pat. No. 4,057,027 was issued to Foster on Nov. 8, 1977. Another was issued to Hark on Sep. 27, 1983 as U.S. Pat. No. 4,406,162 and still yet another was issued on Apr. 17, 1984 to Arena as U.S. Pat. No. 4,443,202.
Another patent was issued to Foster on Nov. 19, 1985 as U.S. Pat. No. 4,553,945. Yet another U.S. Pat. No. 5,988,092 was issued to Price on Nov. 23, 1999. Another was issued to Buswell on Jul. 23, 1969 as U.K. Patent No. GB1,159,269 and still yet another was issued on Jul. 8, 1981 to Hark as U.K. Patent No. GB1592451. Another was issued to Buzzi, et al. on Mar. 12, 1980 as U.K. Patent No. GB2028746 and still yet another was issued on May 21, 1980 to Levi as U.K. Patent No. GB2033324.


A Scheme-1 Termination scheme maximizes system signaling rates by minimizing the signal settling-time when the distance from the middle node to the intersection of the transmission lines is much smaller than the sum of the distances from the end nodes to the intersection of the transmission lines. If the distance from the middle node to the intersection of the transmission lines is not much smaller than the sum of the distances from the end nodes to the intersection of the transmission lines, it has been discovered that a Scheme-2 Termination scheme minimizes the signal settling-time. Alternately, when a Scheme-3 Termination scheme is available, the Scheme-3 Termination scheme maximizes system signaling rates by minimizing the signal settling time when the third transmission line length is more than the second transmission line length divided by two. Otherwise a Scheme-1 Termination scheme minimizes the signal settling time. Additionally, for a given termination scheme, the settling time can be changed by adjusting the lengths of the transmission lines. The impact of such adjustments on settling time can be predicted and maximized by following certain formulas.

1. Field of the Invention
The present invention relates to digital signaling systems and more particularly to controlling the signal settling time of digital signaling systems.
2. Description of the Related Art
In computer and information processing systems, various integrated circuit chips must communicate digitally with each other over common buses. The signal frequency at which this communication occurs can limit the performance of the overall system. Thus the higher the communication frequency, the better. The maximum frequency at which a system communicates is a function not only of the time that it takes for the electromagnetic wavefronts to propagate on the bus from one chip to another, but also of the time required for the signals to settle to levels that can be reliably recognized at the receiving bus nodes as being high or low, referred to as the settling time.
The length of the settling time is a function of the amount of reflection and ringing that occurs on the signal bus. The more effective the termination of a bus system, the smaller the effects of reflection and ringing in the system and the shorter the overall settling time of the signal.
It is known to terminate a bus using a number of different schemes. Three types of termination schemes are referred to as a Scheme-1 Termination scheme, a Scheme-2 Termination scheme and a Scheme-3 Termination scheme. With a 3-node system having a transmission line characteristic impedance of Z ohms everywhere on the line, a middle node is defined as the node having the shortest distance from the intersection of the transmission lines, and the remaining two nodes are defined as end nodes. The middle buffer is defined as the buffer directly associated with the middle node.
A Scheme-1 Termination scheme is characterized as follows. When it is receiving signals, each of the end node output buffers acts as a pull-up terminator (i.e., the end of the transmission line is coupled to the upper power rail via a resistance that is equal to the characteristic impedance of the line) and the middle node output buffer is tri-stated (i.e., functions as an open circuit). When it is driving signals, the output buffer of an end node pulls up through Z ohms and pulls down through Z ohms; the middle node output buffer pulls up through Z ohms and pulls down through Z/2 ohms.
A Scheme-2 Termination scheme is characterized as follows. The output buffer at each node acts as a pull-up terminator when it is receiving signals. When it is driving signals, each node""s output buffer pulls up through Z ohms and pulls down through Z/2 ohms.
A Scheme-3 Termination scheme is characterized as follows. With the Scheme-3 Termination Scheme, the transmission lines are coupled to a network of resistors at the intersection rather than being directly connected. The output buffer at each node acts as a pull-up terminator when receiving signals. When it is driving signals, each node""s output buffer pulls up through Z ohms and pulls down through a very low resistance to achieve large voltage swings.
It is desirable to determine which termination scheme provides better signaling characteristics, such as minimum settling time, for a particular system geometry. It is also desirable, if constrained to use a particular scheme, to determine how to adjust the lengths of the transmission lines so as to minimize settling time.
It has been discovered that a Scheme-1 Termination scheme will maximize system signaling rates by minimizing the signal settling-time when the distance from the middle node to the intersection of the transmission lines is much smaller than the sum of the distances from the end nodes to the intersection of the transmission lines. If the distance from the middle node to the intersection of the transmission lines is not much smaller than the sum of the distances from the end nodes to the intersection of the transmission lines, it has been discovered that a Scheme-2 Termination scheme will minimize the signal settling-time.
Alternately, when a Scheme-3 Termination scheme is available, the Scheme-3 Termination scheme maximizes system signaling rates by minimizing the signal settling time when the third transmission line length is more than the second transmission line length divided by two. Otherwise a Scheme-1 Termination scheme minimizes the signal settling time.
More specifically, in one aspect, the invention relates to a method of selecting a termination scheme between a first scheme and a second scheme to minimize signal settling time in a three node system having first, second and third transmission lines connected at a junction. The method includes: determining a first transmission line length of the first transmission line; determining a second transmission line length of the second transmission line; determining a third transmission line length of the third transmission line, the first transmission line length being greater than the second transmission line length and the second transmission line length being greater than the third transmission line length; selecting the first termination scheme if the third transmission line length is short relative to the combination of the first transmission line length plus the second transmission line length, otherwise selecting the second termination scheme.
In another aspect, the invention relates to a method of selecting a termination scheme from a first termination scheme, a second termination scheme and a third termination scheme to minimize signal settling time in a three node system having first, second and third transmission lines connected at a junction. The method includes: determining a first transmission line length of the first transmission line; determining a second transmission line length of the second transmission line; determining a third transmission line length of the third transmission line; selecting the first termination scheme if the third transmission line length is less than half of the second transmission line length otherwise selecting the third termination scheme.
In another aspect, the invention relates to a method of adjusting line lengths in a three node system to minimize signal settling time. The method includes: determining whether a first termination scheme, a second termination scheme or a third termination scheme is used by the three node system; determining a first transmission line length of a first transmission line; determining a second transmission line length of a second transmission line; determining a third transmission line length of a third transmission line, the first transmission line length being greater than the second transmission line length and the second transmission line length being greater than the third transmission line length; adjusting, when the first termination scheme is used, the first transmission line length, the second transmission line length and the third transmission line length to minimize the sum of two times the first transmission line length plus four times the third transmission line length; adjusting, when the second termination scheme is used, the first transmission line length, the second transmission line length and the third transmission line length to minimize the sum of three times the first transmission line length plus the second transmission line length; and, adjusting, when the third termination scheme is used, the first transmission line length, the second transmission line length and the third transmission line length to minimize the sum of the first transmission line length plus the second transmission line length. These formulas for the effects of such adjustments on settling time assume that, following such adjustments, the first transmission line length remains greater than the second transmission line length, and the second transmission line length remains greater than the third transmission line length.

Method for determining optimal configuration for multinode bus


Provided are methods of providing dynamic messages on a software bus. Such methods may include generating a dynamic message that corresponds to a service request from an application that is connected to a software bus. The dynamic message includes an executable portion that is executed to perform an action. The dynamic message is submitted to the bus for execution at a time after submission.

Middleware may refer to a family of computer software that permits the interconnection, usually over a network, of disparate software components or applications possibly running across heterogeneous computing platforms. Middleware may be used to support complex distributed applications including web servers, application servers, content management systems, and more generally to support software products and tools that may be part of an information technology (IT) system. Use of such middleware may also be used to link new applications to older legacy systems. For example, service oriented architecture may use a service bus, which may be referred to as an enterprise service bus (ESB), which is a distributed software architecture implemented from a collection of middleware services to provide integration capabilities.
An ESB may create a virtual environment layered on top of an enterprise messaging system where services are advertised and accessed. A message bus or service bus may deliver foundational services for more complex architectures via an event-driven and messaging middleware. In this regard, an ESB may be a message transaction system that is a logical channel that carries messages that can be viewed by multiple recipients. For example the service ticket may be created and the corresponding data may be put on a message bus that can be processed by one or more systems depending on their interest in that particular ticket. Any system that has interest in the ticket may read the information from the message bus.
A service bus may be a logical concept that allows applications to be connected. In this regard, a service bus may allow the decoupling of data from the services acting on the data. Service buses may be used to pass events from one service to one or more other services. However, such events may be static in nature, containing a point in time snapshot of whatever data is contained therein.

Bus-based dynamic evaluation with dynamic data lookups


Described herein are systems and methods that provide for asymmetric image splitter image stream applications. In one embodiment, a system supporting image multi-streaming comprises an asymmetric image splitter engine that splits super-frame image streams into two or more image streams and a fractional clock divider circuit. The fractional clock divider may comprise a digital feedback control loop and a one-bit sigma delta modulator. The fractional clock divider circuit may provide compatible display clock frequencies for each of the two or more image streams. When a multi-image stream comprises the two image streams, the asymmetric image splitter engine adjusts a vertical asymmetry of a first image stream with a shortest height to same height as a second image stream by adding vertical padding to the first image stream. The super-frame image streams may comprise image streams from video, LIDAR, radar, or other sensors.

Gigabit Multimedia Serial Link (GMSL) serializer and deserializers (SerDes) may support the high bandwidth, complex interconnect, and data integrity requirements required for a variety of applications. For example, but without limitations, the applications may include low-power requirements for cameras and widely varying bandwidth of sensor data aggregations. Using shielded twisted pair (STP) or coax cables of up to 15 meters, GMSL serializers and deserializers may meet stringent electromagnetic compatibility (EMC) requirements of the automotive and other industries. In some embodiments, the applications may include future automotive infotainment and advanced driver assistance systems (ADAS).
Spread-spectrum capability may be built into each serializer and deserializer IC to improve the electromagnetic interference (EMI) performance of the link, without the need for an external spread-spectrum clock. Interoperation of serializers and deserializers within the family allows the use of different interfaces at each end of the link. In addition to driving high-resolution central/rear-seat displays and instrument clusters, GMSL SerDes systems can also be used in megapixel camera systems.
In some embodiments, GMSL SerDes systems may be implemented with asymmetric image splitters (e.g., an asymmetric side-by-side dual-view splitter engine) to receive a single super video stream containing multiple display images. In order to generate the video clocks for individual displays within the video multi-streaming system, phase lock loop (PLL) oscillators may be utilized in the asymmetric image splitter blocks. The PLLs may require additional cost, size and power consumption.
Accordingly, what is needed are systems and methods that may implement an asymmetric image splitter clock generation block without PLLs.

Systems and methods for asymmetric image splitter clock generation


Apparatus for computational adaptive imaging comprises the following: an image information acquirer, which provides information relating to the refractive characteristics in a three-dimensional imaged volume; a ray tracer, which uses the information relating to the refractive characteristics to trace a multiplicity of rays from a multiplicity of locations in the three-dimensional imaged volume through the three-dimensional imaged volume, thereby providing a location dependent point spread function, and a deconvolver, which uses the location dependent point spread function, to provide an output image corrected for distortions due to variations in the refractive characteristics in the three-dimensional imaged volume.

Post acquisition image processing is well known in the literature. Publications which describe the general state of the art in post acquisition image processing are: Lim, J. S. "Two dimensional signal and image processing". Englewood Cliffs, N.J. Prentice Hall. (1990); Russ, J. C. "Image processing handbook". CRC Press. (1992); Pratt, W. K. "Digital image processing". NY John Wiley & Sons, Inc. (1991); Rosenfeld, A. and Kak, A. C. "Digital picture processing". Academic Press. (1976); Castleman, K. R. "Digital Image Processing". Prentice-Hall Inc. Englewood Cliffs, N.J. (1979).
Imaging which provides information relating to refractive characteristics in a imaged volume is known for extremely limited applications. In microscopy, Smith, Nomarski and Differential Interference Contrast (DIC) imaging is known and is described in the following publications: Nomarski, G. "Microinterferometer differential a ondes polarisees". J. Phys. Radium 16:9S–11S (1955); Lang, W. "Differential-Interferenz-Miikroskopie". Carl-Zeiss, Oberkochen (1975); Inoui, S. and Spring, K. S. "Video Microscopy: the fundamentals". 2nd edition. Plenum Press, NY. (1997). Tanford, C. "Physical chemistry of macromolecules". John Wiley NY. (1961). Appendix C describes classical Rayleigh interference methods, Philpot and Svenson methods based on schlieren image, Lamm method of line displacement, and Gouy interference method all developed for determination of one dimensional refractive index variations.
Computer analysis of DIC imaging is not readily achieved. Known instances are described in the following publications: Allen, R. D., Allen, N. S. and Travis, J. L. "Video-enhanced contrast, differential interference contrast (AVEC-DIC) microscopy: a new method capable of analyzing microtubule related motility in the reticulopodial network of Allogromia laticollaria." Cell Motility 1: 291–302 (1981); Cogswell, C. J. and Sheppard, C. J. R. "Confocal differential interference contrast (DIC) microscopy: including a theoretical analysis of conventional and confocal DIC imaging". J. Microsc. 165:81–101 (1992); Gelles, J., Schnapp, B. J. and Sheetz, M. P. "Tracking kinesin-driven movements with nanometer-scale precision", Nature 331:450–453 (1988); Hdusler, G. and Kvrner, E. "Imaging with expanded depth of focus". Zeiss Inform. 29: 9–13 (1987); Preza, C., Snyder, D. L. and Conchello, J-A. "Image reconstruction for three-dimensional transmitted light DIC microscopy". SPIE 2984:220–231 (1997); Schormann, T. and Jovin, T. M. "Contrast enhancement and depth perception in three-dimensional representations of differential interference contrast and confocal scanning laser microscope images". J. Microsc. 166:155–168 (1992).
Computerized ray tracing between discrete refractive and reflective surfaces is extremely well developed, but is not well known in the environment of non-homogeneous indices of refraction. This area is described in the following publications: Hecht E. and Zajac A. "Optics" 2nd ed. Addison-Wesley Reading Mass. (1997); Jenkins, F. A, and White, H. E. "Fundamentals of optics". McGraw-Hill, NY (1950) ch. 8: Ray Tracing.
Calculation of point spread functions (PSF) is extremely well known as described in the following publication: Born M. and Wolf E. "Principles of Optics" Pergamon London (1959); Goodman J. W. "Statistical Optics" John Wiley & Sons NY (1985); Hecht E. and Zajac A. "Optics" 2nd ed. Addison-Wesley Reading Mass. (1997); Gibson S. F. and Lanni F. "Diffraction by circular aperture as a model for three-dimensional optical microscopy". Opt. Soc. Am. A 6:1357–1367 (1989); Gibson S. F. and Lanni F. "Modeling aberrations due to mismatched layers for 3-D microscopy" SPIE optics in complex systems 1319:470–471 (1990); Gibson S. F. and Lanni F. "Experimental test of an analytical model of aberration in an oil-immersion objective lens used in three-dimensional light microscopy". J. Opt. Soc. Am. A 8:1601–1613 (1991).
Deconvolution of three dimensional microscopic images having location independent PSF is well known and is described in the following publications, some of them authored by some of the present inventors: Jansson, P. A. ed. "Deconvolution of images and spectra". Academic Press NY (1997); Agard, D. A. and Sedat, J. W. "Three-dimensional architecture of a polytene nucleus". Nature 302:676–681 (1984); Agard, D. A., Hiraoka, Y., Shaw, P. and Sedat, J. W. "Fluorescence microscopy in three dimensions". Methods in Cell Biology 30: 353–377 (1989); Castleman, KR. "Digital Image Processing". Prentice-Hall Inc. Englewood Cliffs, N.J. (1979). Correction of telescopic images by the use of suitably distorted mirrors and deconvolution of two dimensional telescope images having location dependent PSF are described in the following publications: Boden, A. F., Reeding, D. C, Hanisch, R. J., Mo, J. and White, R. "Comparative results with massively parallel spatially-variant maximum likelihood image restoration". Bul Am Astr. Soc 27:924–929 (1995); Boden, A. F., Reeding, D. C, Hanisch, R. J. and Mo, J. "Massively parallel spatially-variant maximum likelihood restoration of Hubble space telescope imagery". J Opt Soc Am A 13: 1537–1545 (1996); Jansson, P. A. ed. "Deconvolution of images and spectra". Academic Press NY (1997), Tyson R. K. "Principles of Adaptive Optics" Academic Press NY (1991). Reconstruction of blurred images from point objects is described in the following publications: Carrington, W. A., Lynch, R. M., Moore, D. W., Isenberg, G., Fogarty, K. E. and Fay, F. S. "Superresolution three-dimensional images of fluorescence in cells with minimal light exposure". Science 268:1483–1487 (1995), Femino, A. M., Fay, F. S., Fogarty, K., and Singer, R. H. "Visualization of single RNA transcripts in situ". Science 280:585–590 (1998).

The Regents of the University of California


A sensor for measuring mud resistivity in a borehole includes a transmitter having a magnetic moment in a first direction; and a receiver having a magnetic moment in a second direction, wherein the first direction and the second direction are substantially different, wherein the transmitter and the receiver are disposed in an insulating collar of a downhole tool, and wherein the transmitter is disposed at a selected distance no more than 10 inches from the receiver along a longitudinal axis of the downhole tool.

1. Field of the Invention
The invention relates generally to resistivity logging of formations penetrated by a wellbore. More particularly, the invention relates to sensors that can be used to determine resistivity of mud in the wellbore.
2. Background Art
Oil and gas exploration requires a vast amount of information about the properties of the formations. Among various logging techniques, resistivity logging can provide useful information to locate hydrocarbon reservoirs. Various resistivity logging tools, including induction logging tools, are known in the art. One example of an induction logging tool may be found in U.S. Pat. No. 5,157,605 issued to Chandler et al. Various factors in the borehole may affect the accuracy of induction measurements. U.S. Pat. No. 5,041,975 issued to Minerbo et al. discloses a wellbore correction system for improving the accuracy of measurements made by induction logging apparatus. The correction system disclosed in Minerbo et al. corrects for errors arising from borehole effects, which may include effects due to currents flowing in the mud in the borehole, irregular shapes of boreholes, or tool eccentering. To correct for these borehole effects, it is often necessary to know the resistivity (or conductivity) of the mud in the wellbore. The mud conductivity often needs to be known with good accuracy because the mud conductivity may be orders of magnitude larger than the formation conductivity, and, therefore, errors of a few percent in mud conductivity may have a major impact on the accuracy of the determined formation conductivity.
To determine mud conductivities, various sensors have been used in the art, including an Auxiliary Measurement Sub (AMS sub). The AMS sub is typically located above an induction well logging apparatus and provides measurements of mud resistivity in the wellbore in addition to other measurements, such as temperature measurements and tool acceleration measurements. However, the AMS sub does not always provide accurate mud resistivity, due to potential influence of the formation resistivity.
U.S. Pat. No. 5,574,371 issued to Tabanou et al. discloses an improved mud sensor. This sensor is disposed on a probe that is connected to the bottom of a tool string. This sensor "looks" down instead of sideways to minimize the influence of the formation resistivity. This patent is assigned to the assignee of the present invention and is incorporated by reference in its entirety.
FIG. 1 shows a well logging apparatus including a mud sensor, such as those disclosed in the Tabanou et al. patent. As shown, a well logging apparatus 24 is disposed in wellbore 12. The well logging apparatus 24 may be any induction well logging apparatus, which may be a wireline tool or a logging-while-drill (LWD) tool. A mud resistivity sensor 26 is connected to the bottom 24a of the well logging apparatus 24. The sensor 26 is adapted to measure the resistivity, Rm, of the mud 18 below the sensor 26 in the wellbore 12.
FIG. 2 shows a detailed structure of sensor 26 of FIG. 1, as disclosed in the Tabanou et al. patent. As shown, the sensor 26 includes a current injector electrode (A0) 37 for emitting a current I0 into the mud 18, a current return electrode 34, which may be the conductive part of a downhole sub, for receiving the current I0 from the mud, and a pair of measurement electrodes (M1, M2) 36 for measuring the voltage drop between them. When a current I0 is emitted from the current injector electrode (A0) 37 and returned to the current return electrode 34, such current I0 propagates in the mud 18 in a direction approximately parallel to the longitudinal axis 24b of the well logging apparatus 24, when the current I0 passes in front of the measurement electrodes (M1, M2) 36. This provides measurements that are less influenced by the formation conductivity.
These prior art mud sensors use galvanic electrodes, which need to be in contact with the mud. These electrodes are exposed on the tool body and are typically insulated from the conductive tool body by insulating materials. The insulating material electrically isolates these electrodes from the conductive parts of the tool and also protects the electronics inside the tool from the harsh environment downhole. However, with the borehole being drilled deeper and deeper, the temperatures and pressures encountered by these tools increase accordingly, making it difficult for the insulating material to maintain good seal against the high pressures (up to 20,000 psi) and high temperatures downhole.
Therefore, there exists a need for better mud sensors and methods for mud resistivity measurements.

Method and apparatus for measuring mud resistivity


The present invention provides a mobile unit (e.g., phone) for wireless communication that includes an antenna for detecting wireless fidelity (Wi-Fi) signals from a local area network and logic for switching the unit's operation from conventional cellular transmissions to Wi-Fi transmissions (i.e. 802.11) upon detection of Wi-Fi signals. The handheld device can communicate with a Public Switched Telephone Network (PSTN) using Voice Over Internet Protocol VOIP. In one embodiment, the logic for performing the switch to Wi-Fi transmission is programmed into a subscriber identity module (SIM) card in the device and can perform the switch automatically or in response to manual input after prompting the user. Memory and code in the mobile unit measure and store the duration of both cellular and Wi-Fi transmissions by the mobile unit.

Wireless service providers provide communications services between a mobile unit, e.g., wireless phone, Personal Data Assistant (PDA), computer, etc., and another user. Generally, the mobile unit communicates with a wireless network via a wireless communications protocol such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Global System for Mobile communications (GSM), General Packet Radio Service (GPRS), etc. The wireless network in turn provides connectivity to the telecommunications network, which typically comprises switches interconnected by cables or fiber and provides communications services to the other user.
As the proliferation of wireless services has expanded, so have the types of service offerings to reach different market segments. One of the fastest growing market segments is for prepaid wireless services. However, prepaid wireless services are often not cost effective for wireless service providers. Generally, when a prepaid wireless subscriber attempts to place or receive a telephone call, the network accesses a database to verify that the subscriber's account is current and has a remaining balance available for use. Many times, the access to the database is maintained for the duration of the call to update the subscriber's account in real time. This process is costly and may use resources that could otherwise be used to provide other services.
In addition to the proliferation of conventional cellular networks, Wireless Fidelity (Wi-Fi) networks (or "Hot Spots") are being installed by many major telephone carriers to provide added value to their basic retail business. Generally, hot spots are designed to attract customers into businesses (e.g., coffee shops, airports, bookstores, etc.) by means of the added value of enabling consumers to use their laptops or PDA's for Internet access while in these locations. However, current hot spot networks are largely limited to conventional Internet services and do not provide ready access to Voice Over Internet Protocol (VOIP) communication.
Furthermore, when a mobile unit switches to VOIP communication, it locks out conventional cellular transmissions, preventing wireless service providers from tracking the duration of VOIP calls by means of remote servers and updating the subscriber database as described above.
Therefore it would be desirable to provide mobile units than can utilize Voice Over Internet Protocol (VOIP) transmissions through a Wi-Fi network, as well as internally track the duration of such calls, allowing seamless time accounting for both conventional cellular and VOIP communication.

Using a handheld communication device with a hot spot network


A device for producing a scaled stream with a controllable scaled-stream thickness has a sheet guiding device for receiving therein a stack of sheets, a first transport means, which has a selectively operable or controllable drive, which engages only the lower surface of the stack of sheets and which is arranged relative to the stack of sheets in such a way that the stack of sheets rests thereon with at least a first part of its weight, a second transport means, which is arranged behind the first transport means when seen in the direction of the stream of sheets, which is arranged relative to the stack of sheets in such a way that, when the second transport means is operated without operating the first transport means, it will transport only sheets which have already been drawn out of the stack of sheets by the first transport means, and which is also arranged relative to the stack of sheets in such a way that the stack of sheets rests thereon only with a second part of its weight, the second part of its weight being small in comparison with the first part; a scaled-stream thickness detection device for detecting the scaled-stream thickness, which operates or controls the drive of the first transport means in response to the detected scaled-stream thickness.

A stacked-sheet prefeeder normally comprises a sheet guiding device for receiving therein a comparatively large stack of sheets, and a device for producing a scaled stream, which removes from the lower surface of the stack of sheets held in the sheet guiding device sheets in the form of a stack or in a scalelike mode of arrangement and which supplies the resultant scaled stream to an intermediate tray from which individual sheets are removed by a separation device so that they can be processed subsequently. It follows that such a scaled-stream production device is normally a component of a two-step separation principle in the case of which a scaled stream is first formed from a large stack of sheets, the scaled stream being then, finally, converted into a stream of paper consisting of separate sheets. Such a scaled-stream production device comprises, typically, a feed roll engaging a stack of sheets on the lower surface of the entire stack, which is held by the sheet guiding device, and transporting the stack of sheets in the direction of the intermediate tray. For limiting the height of the stack, a stack height limitation device is typically arranged in the area of the lower edge of the entire stack; the typical components of the stack height limitation device are a rotating roll and a stationary roll, which is arranged at a fixed distance from the rotating roll and the free distance of which delimits the height of the substacks removed from the lower surface of the entire stack. The scaled stream produced by this type of device is often irregular with regard to the scale distances and the scaled-stream thickness.
DE-A 29 30 270 discloses a means for detecting irregularities in the sheet supply to a sheet-processing machine, which is provided with a measuring device for detecting a size that increases as the number of superimposed sheets increases and an evaluation means with the aid of which an electric signal can be supplied if irregularities should occur. FIG. 1 shows a feeder with a stack to be fed from which the sheets are removed by means of a suction device and are fed to the printing machine via a feed table and alignment devices. Prior to the feed table, a feed roll is provided, which can be lifted by means of a suitable control so that a respective new sheet can be introduced. This feed roll is spring urged towards a lower roll. The distance between these rolls corresponds to the thickness of the sheets disposed between the rolls, the distance being measured by a distance sensor. Suitably weighted or averaged output signals of the distance sensor are compared with a stored reference value so that a double sheet or an imperfect sheet can be identified.

Device for producing a scaled stream with a controllable scaled-stream thickness


A flush-mounted, spring-activated utility hook assembly (10) designed to be attached to the side rails (188) of a pick-up truck or to a vertical wall. The assembly (10) consists of a cover plate (130) having a hook slot (136) from where a spring-biased utility hook (112) pivots from a retracted position to an extended functional position. The assembly (10) incorporates a hook release assembly (80) which includes a hook release tab (104) that projects from the surface of the cover plate (130). When the assembly (10) is not in use, the utility hook (112) is maintained in a retracted position by the hook release assembly (80). When the hook release tab (104) is moved outward, the assembly (180) releases and causes the hook (112) to move into its extended functional position. When a pair of assemblies (10) are attached to a truck, a tie-down cord can be attached between the two hooks (112) to secure a load. When the assembly (10) is attached to a vertical wall, it can be used to hang a variety of items when the hook (112) is placed in the extended position.

The present invention relates to a tie down fitting and more particularly to a set of retractable tie down fittings that are mounted within stake holes located on the side rails of a pick-up truck. The tie down fittings are used for securing truck bed cargo located on the bed of a pick-up truck.
In most common way to secure cargo located on the truck bed is by using tie downs which provide the anchorage to maintain the originally loaded position of the cargo. The usual tie down is in the form of an eye cleat or hook that is attached to the side rails of a truck bed by screws or similar devices and in some designs through specially cut openings in the truck's side rails. Finding the proper location for cutting the openings, as well as the actual installation of the tie downs, can be a long and painstaking process and if bolts are used, rather than screws, access to both sides of the truck's side rail is required.
Due to the semi-permanent nature of the tie down hook's installation and because the hook openings which remain may detract from the original appearance of the truck it is impractical for a truck owner to remove the tie downs for use on another truck.
A search of the prior did not disclose any patents that read directly on the claims of the instant invention, however, the following U.S. patents are considered related:
______________________________________ U.S. Pat. No. INVENTOR ISSUED ______________________________________ 4,762,449 St. Pierre, et al 9 August 1988 4,295,765 Burke 20 October 1981 3,102,708 Crain 3 September 1963 ______________________________________
The U.S. Pat. No. 4,762,449 St. Pierre, et al patent discloses a tie down fitting adapted to fit within a stake hole of a pickup truck. The fitting includes a cover plate that fits over the top of the stake hole and a clamping plate that fits over the bottom of the stake hole. The cover plate is secured to the clamping plate by means of threaded fasteners. The fitting includes aligned slots in the two plates that receive a hook member which pivotally moves between a recessed position flush with the wall section to an extended position where it can be used to engage a cargo securing line. To move the hook member from its recessed position to its extended position a finger on a hand is used to press the hook member to cause it to pivot to its extended position.
The U.S. Pat. No. 4,295,765 Burke patent discloses a tie-down structure that includes a body member having a top wall, an outwardly flaring side wall and a threaded stem. The treaded stem extends through an opening in a supporting surface, and a plug member and threaded means as disposed on the threaded stem on a side of the supporting surface opposite to that of the head. With this arrangement, the plug member is freely movable on the threaded stem of the body member.
The U.S. Pat. No. 3,102,708 Crain patent discloses a retractable rope hook that mounts on the top rail of a truck. The rope hook includes a housing that is attached to a mounting plate and a hook member vertically and slidably disposed within a cavity in the housing. Within the housing is also located a compression spring that biases the hook member into its raised position. Interposed between the housing and hook member is a latch that controls the movement of the hook member. The latch is activated by a mechanical actuating lever located on the upper surface of the mounting plate.
For background purposes and as indicative of the art to which the invention is related reference may be made to the remaining cited patents.
______________________________________ PATENT NO. INVENTOR ISSUED ______________________________________ 5,326,203 Cockrell 5 July 1994 5,271,128 Hook 21 December 1993 WO91/04883 WIPO 18 April 1991 4,909,658 Townsend 20 March 1990 4,657,299 Mahan 14 April 1987 4,531,775 Beals 30 July 1985 3,966,250 Winskas 29 June 1976 3,951,250 Ott 2 March 1976 3,298,652 Burdick 17 March 1965 ______________________________________

Flush-mounted, spring-activated utility hook assembly


An electromagnetic drive apparatus and method are operative to rotate a magnetically levitated object for an indefinite period of time. The object, such as a spinning magnetic top with a spindle, is levitated over a base magnet and a horizontal component of a pulsed magnetic field is applied at the region of the spinning magnetic top to maintain the top spinning and levitating indefinitely. The pulsed magnetic field is generated by applying a pulsed dc voltage or an ac current to a coil situated in proximity to the top. The coil may have a cylindrical or oblong shape and a core may be provided in the coil. Levitation stability and duration are improved by positioning a loosely fitting washer on the spindle of the spinning magnet so as to permit relative rotation therebetween during application of the pulsed magnetic field.

Levitation of one magnet above another against the force of gravity can be accomplished by positioning the two magnets with the polarity of the upper (levitated) magnet opposite that of the lower (supporting) magnet so that the like poles (north or south) of the two magnets confront one another. Such nearly frictionless supporting of one magnetic body by another holds great potential for technological and commercial applications and great appeal for recreational and entertainment applications. Unfortunately, such juxtapositions of magnets are inherently unstable and usually must be mechanically constrained against lateral and flipping movement if the magnetic vertical lifting force is to be effective or useful. Nevertheless, special methods and apparatus have been developed for achieving magnetic levitation that do not require mechanical constraints.
One approach is to use electromagnets or combinations of permanent magnets and electromagnets with sophisticated automatic control systems that rapidly alter or modify the magnetic fields so as to prevent the lateral and flipping movements. This is one technique that is applied, for example, in magnetically levitated (maglev) trains and spinning rotor molecular drag vacuum gauges. Another method allows one permanent magnet to float (levitate) in the magnetic field of another permanent magnet without the use of any external controls, electrical circuits or mechanical constraints. U.S. Pat. No. 5,404,062 and U.S. patent application Ser. No. 08/413,949 filed Mar. 30, 1995 disclose such a levitation system. This system, now being produced and sold under the registered trademark, LEVITRON.RTM., uses a flat lower magnet to magnetically support or levitate a smaller spinning magnet. The smaller magnet has an annular or ring shape with a non-magnetic spindle fitted into the central hole thereof, the combination thus resembling a toy top. The system is operated by first placing a sheet of nonmagnetic material such as a plastic sheet on the lower magnet. The top is pressed gently against the plastic sheet and is set spinning either manually or with a mechanical device. The plastic sheet, bearing the spinning top, is then manually lifted upwardly. When the top reaches a certain height above the lower magnet (usually about one to four inches), it rises off the plastic sheet and remains spinning stably in space, supported only by the force from the interacting magnetic fields of the two magnets. The top will continue to spin for several minutes, its rotational speed gradually decreasing due to air drag. When the speed falls below that required to maintain stability, the top flips over and falls to the lower magnet.
U.S. Pat. No. 4,382,245 to Harrigan discloses another simple magnetic levitation system which utilizes a dish-shaped lower magnet to magnetically support or levitate a magnetic top spinning coaxially above the lower magnet. The dish-shaped or concave surface of the lower magnet is said to produce radially inwardly directed lines of magnetization which, together with the gyroscopic effect of rotation of the magnetic top, provide stabilization of the levitation system. The Harrigan patent also discloses that the top may be rotated manually or by air jets or rotary or oscillating magnetic or electric fields.
In U.S. patent application Ser. No. 08/506,351 filed Jul. 24, 1995, the disclosure of which is incorporated herein by reference, there are disclosed a method of and an apparatus for extending the duration of levitation of a rotationally stabilized magnetic levitation device, such as that disclosed in U.S. Pat. No. 5,404,062 and the aforesaid U.S. patent application Ser. No. 08/413,949, from its normal duration of several minutes to durations of up to many hours, or essentially indefinitely. That is accomplished by a plurality of fluid streams, such as air, directed at the top, with a radial component and a component tangential to the periphery, of the spinning top. An annular manifold connected to the outlet of one or more small air pumps is used to maintain the top spinning. The manifold distributes the air to a number of slender tubes comprising a set of air jets. The manifold is supported in such a way that the jet outlets or nozzles are arrayed in a circle about the spinning top and in a horizontal plane at the levitating height of the top. The air nozzles are directed in the horizontal plane of the top and the air streams projected in this plane have both tangential and radial components relative to the periphery and spin axis of the top, respectively. The top periphery is preferably provided with reaction surfaces, such as vanes, protuberances, roughened surfaces or the like. Such surfaces react with the air streams coming from the air nozzles and transfer the linear momentum of the air streams to angular momentum of the top, thus maintaining the rotational velocity of the top against air drag.
In the aforesaid U.S. patent application Ser. No. 08/672,672 of which this application is a continuation-in-part, another method of and an apparatus for extending the duration of levitation of a rotationally stabilized magnetic levitation device, such as the levitated spinning top disclosed in U.S. Pat. No. 5,404,062 and U.S. patent application Ser. No. 08/413,949, are disclosed. According to that invention, a flat base magnet is magnetized such that the field lines of its magnetic field are substantially perpendicular to the flat surfaces of the base magnet as described in U.S. Pat. No. 5,404,062 and U.S. patent application Ser. No. 08/413,949. The magnet of the spinning top is magnetized such that the field lines of its main magnetic field are substantially parallel to the spin axis of the spinning top. In that combination, when the top is spun manually about a vertical axis over the base magnet at a rotational speed or spin rate of about 18-35 cycles per second (cps) or about 1080-2100 rpm, the spinning top will be levitated above the base magnet for several minutes, e.g., 2-5 minutes. As used herein, the terms "vertical" and "horizontal" are determined with reference to the local vertical at the spin axis of the top.
According to the invention of the aforesaid application Ser. No. 08/672,672, it is possible to increase the duration of levitation of the spinning top by locating a horizontal component of a magnetic field in the region of the spinning top and pulsing that magnetic field between a minimum and a maximum value at a selected repetition rate. The pulse repetition rate of the field varies from a relatively low pulse rate, e.g., on the order of about 15 pulses per second (pps), to a higher pulse rate, e.g., on the order of about 30 pps. A square wave pulse or haversine wave pulse are both effective in maintaining the top spinning although other pulses including negative or positive or alternating pulses, clipped sine waves, etc., will work.
The pulsed magnetic field is achieved by locating one or more conductive wire coils in a position with respect to the magnet of the spinning top so that when a pulsed dc voltage is applied to the coil a pulsed horizontal field is generated at the spinning top. The pulsed magnetic field is applied before or after the top is spun either manually or by any other means. The spinning top is subjected to the horizontal component of the pulsed magnetic field at a pulse repetition rate less than the spin rate. As the rotational speed or spin rate of the top decreases naturally because of drag, the top will couple to the pulsed magnetic field generated by the coil or coils at a spin rate of about 30 cps (1800 rpm) The spin rate is maintained at approximately 1.25 to 1.5 times the pulse rate.
The magnetic field which generates the horizontal field component at the spinning top is provided by a conductor wire wrapped about the base magnet with the axes of the windings oriented along any horizontal axis, or by a coil or coils disposed above or below the base magnet or in a central opening thereof or above the location of the spinning levitated top with the axis or axes of the field or fields generated thereby arranged along a horizontal axis or axes at any azimuthal angular orientation with respect to the local vertical.
As also described in the aforesaid U.S. Pat. No. 5,404,062 and U.S. patent application Ser. No. 08/413,949, adjustment of the weight of the spinning top is necessary to obtain the proper relationship of spinning top mass and the interacting magnetic fields of the base and top so that levitation of the top can be maintained for a reasonable period of time. The weight adjustment is accomplished by adding or removing washers of different weights to the top spindle and securing them in place with a rubber grommet or O-ring.

Electormagnetic drive method and apparatus for driving a rotationally stabilized magnetically levitated object

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A fabric sleeve is used to hold gravel pack granular material in place over the open (slotted, perforated, punched, louvered, etc.) portions of a well screen. A well screen is described having an attachment device oriented to form longitudinal fabric sleeve pockets parallel to the longitudinal axis of the well screen. The pockets are filled with a gravel pack material.

Gravel pack material (granular material) is commonly used in well construction to stabilize the bore hole and provide filtration to prevent fine grain formation material from entering the well with the liquids or gasses produced. There is considerable advantage in providing a means of attaching a gravel pack filter to the well screen itself prior to the installation of the well screen in the bore hole, as the well driller has then assured that the well can be completed in a manner which will not produce formation material (sand).
There is an existing design which attaches the gravel pack material to the well screen by cementing granular material to the well screen (e.g.; "Aquastream", U.S. Pat. No. 4,624,314). This design results in a product which is somewhat fragile and may not be easily cleaned of clogging formation material or drill cutting. An improvement in that design is described in this application and is achieved by forming the outside shape of the granular envelope with a wave-like or bumpy surface with channels which allow free movement of well cleaning fluid around the outside of the screen, and having its thicker portions covering the slotted (open) sections of the well screen and its thinner parts at the places which are not slotted.
Another presently available well screen design uses granular material in the cavity between two telescoping well screens (Western K-L Associates, Inc. "Pre-Pac" dual wall well screen). This product is in some cases somewhat heavy and larger in diameter than desirable because of the need to use commonly available pipe sizes. Also, the open area available to transmit fluids into the well must be limited to that which can be produced by that slot size which is usable to retain the size of the gravel used in the gravel pack.
Another type of well screen now available uses two wire wound well screens (one inside the other) with a granular gravel pack between them (Johnson Filtration Systems: "Channel Pack (TM)"). This product was borrowed from existing petroleum production technology. The well screen produced is excessively expensive, is of a high shipping weight and its excessive diameter is a disadvantage.

Well screen and completion device having an attached gravel pack