A method is for selecting a coding scheme for use in a wireless packet data communication system. The coding scheme is one of a set of coding schemes that are useable on an uplink or downlink channel. States of support of a mobile station corresponding to the set of coding schemes are set to one of a set of values including supported, unsupported, and unknown support. A portion of an uplink or downlink data transfer for the mobile station is transmitted using a first coding scheme. The state of support of the mobile station for the first coding scheme is set to one of supported and unsupported based on whether the data transfer is received successfully. A quality measurement is performed during the transfer. A second coding scheme is then selected based upon the quality measurement and the set of states of support of the mobile station.

In wireless networks employing General Packet Radio Service (GPRS), a coding scheme for data message transmissions is selected by rules embedded in a fixed network and in a mobile station that are designed to result in the highest data throughput with the fewest possible retransmissions. GPRS is an extension of circuit-switched networks and data transmission services that uses packet radio transmissions to carry data messages using protocols such as Internet Protocol (IP) or X.25 information from mobiles to the network and visa versa, in data blocks, or packets. GPRS is an extension to the circuit-switched Global System for Mobile communications (GSM), having four different coding schemes with effective data rates of 9.05, 13.4, 15.6 and 21.4 kilobits per second (code rates ½, ⅔, ¾ and 1) within the data blocks.
Some GPRS-enabled fixed networks can send a command to a mobile station, such as a cell phone, an Internet-enabled mobile phone or a personal digital assistant, to transmit data blocks using a selected one of the four coding scheme. The error rate of the selected coding scheme may rapidly degrade, however, with changing radio conditions or geographical movements of the mobile device. The mobile unit may have limitations in its coding capabilities and its ability to adapt to coding scheme commands. With the move toward third-generation network standards, there are even more possible problems with high-performance networks that use a wider variety of coding schemes. Mobile stations need to adapt their coding schemes rapidly during a data message when possible, and the fixed network needs to recognize mobile stations that are unable to use certain coding schemes, in order to use a best possible coding scheme and avoid undue retransmissions when a coding scheme is selected that cannot be accommodated by a mobile station.
Current GPRS fixed networks use dynamic link adaptation methods that monitor the quality of packet transfers and select one of the four presently defined channel coding schemes (also referred to herein simply as "coding schemes") based on changing radio conditions. As technologies and protocols emerge and evolve for wireless data transmissions, additional coding schemes will become available. For example, GSM networks incorporating Enhanced Data for Global Evolution (EDGE) with packet-switched enhancements for GPRS have nine additional coding schemes for increased performance. Other wireless network technologies such as GSM/EDGE Radio Access Network (GERAN) and Universal Mobile Telecommunications System (UMTS) provide enhanced coding schemes, requiring network algorithms that can determine the coding scheme adaptability of the mobile station and direct coding scheme commands to the mobile station based on the adaptability. When mobile stations do not respond to all of the defined set of four coding schemes, dynamic link adaptation methods in current use result in sub-optimal data throughput, and in some case, can result in no communication capability with certain mobile stations.

Apparatus and method for a coding scheme selection


Article handling machine (1) having a frame (3) for receiving article handling elements, a roof (7) covering said frame (3), and an electrical cabinet (12) for receiving devices for controlling electrical power supplied to said handling elements, characterized in that the electrical cabinet (12) is pivotally mounted on the roof (7) between an erected position in which the cabinet (12) is substantially perpendicular to the roof (7) for allowing an operator to access inside the cabinet (12) in standing posture, and a lying position in which the cabinet (12) extends substantially parallel to the roof (7).

In article handling machines, handling elements (e.g. carrousels, transfer wheels) are generally driven by powerful electrical motors which require high voltage to be supplied to the machine.
In order to control the electrical power supplied to the handling devices, the machine is usually provided with an electrical cabinet receiving control devices. Electrical cables run through the electrical cabinet and are distributed, via cable trays, to the handling devices.
Such an electrical cabinet is generally positioned aside the machine, either at a distance therefrom, which is not convenient because cables running from the cabinet to the machine may obstruct passage for operators or motorized handling appliances, or adjacent to the machine, which is not convenient either because, in most applications, side walls of a handling machine should offer a free access for operators to the inner volume of the machine in order to allow maintenance operations. In practice, side walls of the handling machines are provided with windows which the operators may open manually to access the inner volume of the machine.
Furthermore, the mere presence of an electrical cabinet is problematic since the cabling must be dismounted for transportation of the machine from the workshop, in which setting operations are conducted, to the client's premises where the machine is re-built together with its cabling. Often the cable length is not the same in the workshop as in the client's premises, or the position initially provided is not suitable.

Article handling machine equipped with a tiltable electrical cabinet


Intelligent hotspot connection systems and methods are provided. The intelligent hotspot connection system includes a storage unit, a wireless connection unit, and a processing unit. The storage unit includes a hotspot information database recording at least one property for each of a plurality of hotspots, and a hotspot preference database recording at least one preference inclination, respectively defining a reference weight for the property and signal strength. The processing unit detects the signal strength of the respective hotspots via the wireless connection unit. The processing unit obtains the preference inclination, and calculates a score for the respective hotspots according to the preference inclination, the property and signal strength of the respective hotspots. The processing unit selects and automatically connects to the hotspot with the highest score via the wireless connection unit.

1. Field of the Invention
The disclosure relates generally to intelligent hotspot connection systems and methods, and more particularly, to systems and methods that automatically determine a hotspot and/or the process for logining to the hotspot according to user preference and hotspot properties.
2. Description of the Related Art
Recently, applications for wireless networks have become more important and valuable due to increased convenience and functions of portable electronic devices. Related infrastructures, such as hotspots/access points, must be set up by the wireless network service provider, such that users can link and login to the wireless network service via their portable electronic devices.
Generally, when users want to link to a wireless network, a wireless network scanning module in their electronic devices must be activated to detect available wireless network providers in a surrounding environment. Users must determine and select a specific provider by themselves, and manually operate their electronic devices to link to the hotspot supplied by the specific provider. In some situations, a user may respectively have several accounts for wireless network providers, and the signal strength, charge conditions and connection mechanisms for each wireless network provider may be different. Therefore, users usually determine a wireless network provider according to several characteristics such as signal strength, cost, charging rate or security enhancement. It is troublesome for users to determine which wireless network provider or hotspot should be connected. Additionally, since there are different login procedures for each wireless network provider, users must intimately know login procedures and corresponding account names and passwords for different wireless network providers. Memorization and operation of several account names/passwords and login procedures are indeed troublesome for users.
U.S. Pat. No. 7,191,239 discloses a method and system to customize and update a network connection application for distribution to multiple end-users. In this patent, the system can automatically recognize and mark the hotspots which belonging to one alliance for helping the users to select. However, no automatic determination mechanism for hotspots based on user preferences is provided.


A rotatable display carousel may include a stationary central rod and a bottom plate rotatably mounted about the central rod. A plurality of shelf sections may be rotatably positioned above the bottom plate respectively. A rotating mechanism may be used to simultaneously rotate each shelf section respectively by rotating the bottom plate about the central rod. In this manner, each shelf section rotates in sync based upon a rotational speed of the bottom plate. The central rod remains stationary while the bottom plate and the shelf sections rotate respectively. The structural arrangement enables the plurality of shelf sections to be dynamically linked to the bottom plate in such a manner that the shelf sections synchronously rotate upon rotation of the bottom plate.

1. Technical Field
This invention relates to display cases and, more particularly, to a rotatable display carousel for providing a user a means of exhibiting a plurality of products within a confined area.
2. Prior Art
Retail outlets have employed a number of different techniques for displaying merchandise and promotional items to customers. Wall and floor cabinets are commonly used as permanent fixtures to display merchandise, and many of these have locking drawers or doors to prevent access to the items on display except by an employee with a key. In some instances, portable cases are used to display promotional items and products which are smaller in size such as watches, jewelry or the like. These portable cases typically rest on top of a base cabinet, or on a shelf.
One prior art example shows a display case that comprises a first section having a top wall, a bottom wall and a back wall connected between the top and bottom walls, and, a second section having opposed side walls with a front wall connected between them. The second section slides into engagement with the first section to form a closed interior. The bottom wall of the first section is integrally formed with a bracket which includes first and second arms connected in an inverse, L-shape, with one of the arms oriented parallel to and spaced from the bottom wall to form a space within which a shelf is received. A thumb screw or other mounting device extends through the bracket arm to engage the shelf and secure the display case thereto. Unfortunately, this prior art example does not provide a means of rotating the display such that merchandise is effectively displayed to a consumer.
Another prior art example shows an illuminated display apparatus comprising a frame member and a housing for containing a three-dimensional object. The illuminated display apparatus further includes a light source mounted within the housing for illuminating the object contained within the housing of the apparatus. Unfortunately, this prior art example also does not provide a means of rotating the display. In addition, this display is of a limited size, and is not suitable for housing a plurality of differently sized objects simultaneously.
Accordingly, a need remains for a rotatable display carousel in order to overcome the above-noted shortcomings. The present invention satisfies such a need by providing an assembly that is convenient and easy to use, is lightweight yet durable in design, and provides a user a means of exhibiting a plurality of products within a confined area. Such an assembly can be used to display products to promote sales, or to provide a variety of utilitarian functions other than retail commerce. The assembly allows a display to be attractive, as well as conservative in space requirements. The present invention is simple to use, inexpensive, portable, and designed for many years of repeated use.

This patent is subject to a terminal disclaimer.

Rotatable display carousel and associated method


The present invention provides a composite aluminum plate suitable as a target for coating purposes, said plate comprising a surface layer melted on the basis of pure aluminum (Al.gtoreq.99.99), optionally consisting of a pure alloy, e.g., the members of which have a purity greater than or equal to 99.99%, melted on the basis of pure aluminum (Al.gtoreq.99.99); and (2) a supporting layer comprising a hardenable aluminum alloy having a Brinell hardness index HB of at least about 50 after being heat-treated under suitable conditions. This invention further provides a target suitable for physical or sputter coating processes, such as cathodic sputtering and magnetron sputtering. Methods for preparing such a plate and target are also provided.

Several processes have been used for physically coating metal surfaces, including aluminum and aluminum alloy surfaces. One method known as cathodic sputtering involves "atomizing" or "bombarding" a suitable target with high energy gas ions, which are accelerated in an electric field. Using cathodic sputtering, the surface atoms are displaced from the target and deposited on the surface to be coated where they form a layer.
In a modification of the cathodic sputtering method, a magnetic field is applied to the target to increase the sputtering rate significantly, according to the Penning principle. This modified cathodic sputtering technique is referred to as magnetron sputtering. In magnetron sputtering, a small proportion of the energy which is applied to the target is converted into kinetic energy with the majority of energy transformed into heat. To effectively displace atoms from the surface of the target, the heat must be dissipated by intensively cooling the target.
One serious consequence of bombardment heating, arising from, for example, magnetron sputtering, is a marked deterioration in the mechanical stability, including the shape, of the aluminum and aluminum alloy metal target.
To overcome this deterioration in metal stability, and to allow for sputtering with high energy output, prior art teachings have provided composite targets with backing plates, which impart high mechanical stability and good heat conductivity, to improve the physical characteristics of the composite target and its performance during bombardment heating. Such backing plates minimize the heating of the target and its consequent deformation.
Backing plates taught by the prior art for aluminum and aluminum alloy targets typically consist of copper. The two metals, i.e., aluminum and copper, or aluminum alloy and copper, are normally joined by conventional methods such as gluing, soldering or explosive plating. In such target forms, the technique of roll-bonding the metals is not feasible because the thickness of the copper layer in the backing plate cannot be more than 3 mm. Such thicknesses, i.e., thinner than 3 mm, limit the degree of mechanical stability and resistance to heat deformation which can be imparted to the aluminum or aluminum alloy layer by the copper backing. Thus, such prior art targets which employ copper backings are seriously disadvantaged.

Composite aluminum plate and target for physical coating processes produced therefrom and methods for producing same


An access subnetwork node herein comprises one or more add-drop modules, each module including one or more passive optical filters. The one or more add-drop modules are configured to selectively drop a fixed band of wavelength channels from an access subnetwork, via a passive directional coupler, to each of multiple client nodes that actively select to receive client-specific channels within the fixed band. The one or more add-drop modules are also configured to selectively add the fixed band of wavelength channels to the access subnetwork, as received via a passive directional coupler from the multiple client nodes that actively select to transmit client-specific channels within the fixed band. With an access subnetwork node and a client node configured in this way, embodiments herein reduce the complexity and accompanying cost of nodes in an optical network, while also maintaining flexibility for assigning wavelength channels in the network.

Increasing the flexibility with which an optical transport network can assign and route wavelength channels has traditionally increased the efficiency of the network. Reconfigurable optical add/drop multiplexers (ROADMs) have greatly contributed to this increased flexibility by enabling wavelength channels to be selectively added or dropped at any node in the network. However, ROADMs employ fairly complex and expensive components to provide this flexible capability. Furthermore, many of these components are active, meaning that the ROADMs require a power supply infrastructure and an interface for managing faults and upgrades. ROADMs thus prove prohibitive in some contexts.
One such context relates to a network that efficiently transports the traffic of multiple services in a converged fashion. Rather than employing multiple different networks in parallel for transporting these different services (e.g., mobile, business, and residential services), a converged network transports those services together using the same network. A transport network that optically converges different services by transporting those services on different wavelength channels would be advantageous, for a variety of reasons, but has heretofore been stifled by long deployment cycles of equipment, organizational boundaries, and operator considerations. Such a transport network would be advantageous for instance because of its potential for large scalability and efficiency.

Methods and apparatus for a passive access subnetwork


A volume of contents in a container of a work vehicle can be estimated in various examples. One example involves a system with a 3D sensor on a work vehicle, where the 3D sensor captures images of the contents in a container of the work vehicle. The system also includes a sensor for detecting an angle of the container. A processor device that is in communication with the 3D sensor and the sensor determines a volume of the contents in the container using the images and the angle.

Operating a work vehicle, such as an excavator or a scraper, is a highly personal skill. Efficiency—e.g., amount of earth moved by the work vehicle over an amount of time—is one way to measure at least part of that skill. And efficiency is also one way to measure the performance of the particular machine. Measuring efficiency with accuracy and without interjecting an additional step on moving the earth is difficult. Weighing contents of the bucket of an executor interjects additional steps that may cause the overall earth-moving process to be less efficient. Processes used to determine the amount of contents in the bucket without physical contact with the bucket may not accurately estimate the volume of the contents.

Estimating a volume of contents in a container of a work vehicle


A method of forming one or more TSP compacts is provided. The method includes placing one or more TSP material layers in an enclosure and surrounding each TSP material layer with at least one of a pre-sintered tungsten carbide powder, pre-cemented tungsten carbide powder, tungsten carbide powder, or partially sintered tungsten carbide substrates. The method also includes exposing the enclosure to a high temperature high pressure process wherein the at least one of a pre-sintered tungsten carbide powder, pre-cemented tungsten carbide powder, tungsten carbide powder, or partially sintered tungsten carbide substrates bond to the TSP material layers forming a stack of TSP material layers including the TSP material layers one over the other with tungsten carbide bonded to each of the TSP material layers and encapsulating each of the TSP material layers.

This invention is directed to a method of forming and attaching thermally stable polycrystalline diamond ("TSP") materials to form new cutting elements and bits incorporating such cutting elements, as well as to such cutting elements and bits.
A TSP material is typically formed by "leaching" at least a substantial portion of a catalyst, such as cobalt, from a polycrystalline diamond ("PCD") material using a leaching agent. When formed, PCD comprises individual diamond crystals that are interconnected defining a diamond network. Catalyst particles, e.g., cobalt particles, are often found within the interstitial spaces in the diamond network. Cobalt has a significantly different coefficient of thermal expansion as compared to diamond, and as such, upon heating of the PCD, as for example upon frictional heating of the PCD which occurs when the PCD is used to cut earth formations, the cobalt expands, causing cracking to form in the network structure, resulting in the deterioration of the PCD layer. PCD having a second phase metal catalyst will generally not have thermal stability at temperatures above 700° C. By removing, i.e., by leaching, the catalyst (e.g., the cobalt) from the diamond network structure, the PCD layer becomes more heat resistant, as well as less prone to cracking when heated.
Typically, to form a PCD layer, a substrate of cemented tungsten carbide (a substrate where tungsten carbide particles are cemented together with a binder such as cobalt) is placed adjacent to a layer of diamond particles, which may also be premixed with a catalyst, such as cobalt, in a refractory metal enclosure typically referred to as a "can", as for example a niobium can, and the combination is subjected to a high temperature at a high pressure where diamond is thermodynamically stable. This process is referred to as a high-temperature-high-pressure sintering process (an "HTHP sintering process"). This process results in the recrystallization and formation of a PCD ultra hard material layer bonded on the tungsten carbide substrate. The PCD layer is then removed from the substrate by cutting off and by lapping off the substrate, as necessary. The removed PCD layer is then leached to substantially remove all of the catalyst to form the TSP material layer. Typically at least 95%, and in many cases over 98% and even over 99% of the catalyst is removed. Removal of the catalyst frees the interstitial spaces in the diamond network, i.e., it creates voids in the diamond network. The TSP material layer may then be attached to another substrate by brazing, or by a high-temperature-high-pressure process (an "HTHP bonding process") where a cemented tungsten carbide (WC-Co) substrate is provided adjacent the TSP material layer and is heated at a sufficient temperature to melt and get infiltration of a binder, such as the cobalt in the tungsten carbide, to infiltrate the TSP material layer and at a sufficient pressure for attaching the TSP material to the substrate forming a TSP material cutting element, such as a TSP material cutter or compact. Moreover, an infiltrant such as a metal or metal alloy infiltrant, as for example copper, silver, copper alloys and silver alloys, which have a melting temperature that is lower than the melting temperature of the diamond particles, may also be used to infiltrate the TSP material when being attached to the substrate. The infiltrant infiltrates into the voids created by the leaching process attaching the TSP material to the substrate. It should be noted that an HTHP bonding process is not a sintering process as is the HTHP sintering process referred in the formation on the PCD. Moreover, the times, temperatures and/or pressures in an HTHP bonding process may be different than those in an HTHP sintering process. In addition, a sintering process requires a catalyst, whereas the bonding process requires an infiltrant. For convenience the term "HTHP process" is used herein to refer to a process requiring high temperature and high pressure as for example an HTHP sintering process or an HTHP bonding process. It should be noted that the acronym "HPHT" may be used interchangeably with the acronym "HTHP". Both acronyms refer to the same thing, i.e. high pressure and high temperature, or high temperature and high pressure.
The current methods of forming TSP material cutting elements by HTHP sintering diamond particles adjacent a tungsten carbide substrate to form PCD bonded to the substrate and then removing the substrate and leaching the PCD to remove the catalyst is a relatively involved process which is relatively costly. Consequently any cutting element formed with such TSP material will also be costly. As such, methods of forming a TSP materials and method for forming cutting elements incorporating such TSP material which are more efficient and thus, less costly are desired.

Methods of making and attaching TSP material for forming cutting elements, cutting elements having such TSP material and bits incorporating such cutting elements


Cap storing devices, particularly a stand for supporting a plurality of caps of the type having a deformable crown and an extended visor. The stand includes a base and upstanding back, together with a curvate shelf which engages the inner periphery of a folded crown, while the cap visor extends vertically in engagement with the back. A plurality of folded caps thus may be stacked one upon the other in storage mode.

(1) Field of the Invention
Hat or cap storing device, particularly a storage rack for supporting a plurality of baseball-type caps one upon the other with their visors extending vertically in parallel engagement with each other.
(2) Description of the Prior Art
Design Patents: PA0 Mechanical Patents:
PALMENBERG: U.S. Pat. No. Des. 17,098 PA1 ROSENHEIM: U.S. Pat. No. Des. 159,536 PA1 SANDERS: U.S. Pat. No. 466,626 PA1 VISEL: U.S. Pat. No. 657,629 PA1 JAMES: U.S. Pat. No. 1,655,609 PA1 ZIMMERMAN: U.S. Pat. No. 4,616,747 PA1 HALE et al.: U.S. Pat. No. 4,805,782
Prior patentees have provided special clips and support members for the interior of a cap; however, none have suggested an apparatus for suppporting a number of caps stacked one upon the other with the cap visors aligned vertically parallel with the back wall of the support.


An injection control device includes: an area correction unit that calculates an energization time correction amount by performing area correction of a current flowing through a fuel injection valve when executing a current drive of a fuel injection valve to inject a fuel from the fuel injection valve in a multi-stage injection; and a change unit that changes an upper limit guard value of the energization time correction amount according to an injection time of the multi-stage injection during control of the multi-stage injection.

An injection control device is used to inject fuel into an internal combustion engine by opening and closing a fuel injection valve. The injection control device opens the fuel injection valve that is electrically drivable by passing current to the fuel injection valve. In recent years, a normal current profile for energization current based on a command injection quantity has been set, and the injection control device opens the fuel injection valve by applying current to the fuel injection valve on the basis of the normal current profile. The normal current profile is also referred to as a nominal current profile or an ideal current profile. In recent years, due to tightening of regulations for environmental problems, further improvement in the fuel injection accuracy in automobiles has been required as measures to improve fuel efficiency and reduce the amount of harmful substance emission. In particular, since there is a requirement for tightening regulations on the number of fine particles (i.e., PN, that is Particulate Number), fine injection is frequently used, and higher injection accuracy is required.


A bolometer infrared detecting element has a thermal isolation structure in which a temperature detector comprising a bolometer thin film is held floating from a circuit substrate by beams. As infrared rays incident on the temperature detector or reflected by an infrared reflector are absorbed by a protective film and the bolometer thin film, the temperature of the bolometer thin film rises, and the temperature rise is detected as a change in resistance. When a high temperature object whose temperature is equal to or higher than a predetermined temperature or whose output voltage is equal to or higher than a value corresponding to the predetermined temperature is detected, a control temperature setter or a pulse bias setter performs control in such a way as to raise the temperature of a Peltier device stepwise or in a pulse form, or to increase the width of a pulse of pulse bias, or to increase the voltage value of the pulse. This makes it possible to raise the temperature of the infrared detecting element, thereby reducing an afterimage.

1. Technical Field of the Invention
The present invention relates to a bolometer infrared detector that detects infrared rays with a thermal resistance element formed in a thermal isolation structure, and, more particularly, to a bolometer infrared detector comprising a part which reduces an afterimage and an afterimage reduction method which uses the bolometer infrared detector.
2. Description of the Related Art
The infrared detector is divided broadly into a quantum detector which uses a band structure of a semiconductor and so on, and a thermal detector which uses a heat-originated change in material properties such as a resistance and a dielectric constant. The former detector has high sensitivity but needs to be cooled according to the operational principles, whereas the latter, which is called an uncooled detector because it does not require cooling, has many advantages over the quantum detector in production cost and maintenance cost. Thus, the uncooled detector is becoming the mainstream of infrared detectors.
There are a bolometer detector, a pyroelectric detector, and a thermocouple detector as thermal infrared detectors. Generally, each type of detector has a thermal isolation structure, a so-called diaphragm structure, in order to enhance the sensitivity of the detector. The bolometer infrared detector is comparatively superior in its characteristics. Especially, bolometer infrared detectors using vanadium oxide (VOx) as a bolometer material are used as imaging devices which are arrayed in two dimensions to acquire infrared images, as shown in SPIE (year 1996, volume 2746, page 23). The above-described bolometer infrared detector will be explained with reference to FIGS. 1A and 1B. FIG. 1A is a cross sectional view showing an infrared detector 1. FIG. 1B is a cross sectional view showing an infrared detecting element 2 shown in FIG. 1A.
As shown in FIG. 1B, in the device section of the bolometer infrared detector, an infrared reflecting film 12 which reflects infrared rays and a protective film 13 are formed on a circuit substrate 11 in which a readout circuit 11a is formed by a CMOS process. On the infrared reflecting film 12, separated by a cavity 14, a temperature detector 19 comprising a bolometer thin film 16 made of a bolometer material, an electrode 17 connected to an end of the bolometer thin film 16, and a protective film 15 covering those mentioned is formed. The temperature detector 19 is held in air by beams 18 consisting of the electrode 17 and the protective film 15 covering the electrode 17. The electrode 17 is connected to a contact 11b on the circuit substrate 11, and the contact 11b is connected to the readout circuit 11a electrically.
As shown in FIG. 1A, the elements having such a thermal isolation structure are arrayed in a two-dimensional array to constitute the infrared detecting element 2. The infrared detecting element 2 is mounted on a temperature control element such as a Peltier device 3 and is controlled to a constant temperature. The infrared detecting element 2 and the Peltier device 3 are sealed in vacuum by a vacuum package comprising a package 4, a cap 5, an infrared-transparent window 6, and an exhaust pipe 7, and their input and output signals are connected via pins 8 to an external circuit of such as a driver, a signal processor, and a temperature control element driver provided outside.
Infrared rays made incident through an optical system are absorbed partly by the protective film 15 and the bolometer thin film 16 of each infrared detecting element 2, and the remainder passes through them and is reflected by the infrared reflecting film 12 to be made incident on the temperature detector 19 again and absorbed again. The absorbed infrared rays heat the temperature detector 19 and change the resistance of the bolometer thin film 16 (thermal resistance) in the temperature detector 19. As a bias current from the readout circuit 11a is supplied, the resistance change is read out as a voltage change so that the temperature of a subject is measured.
Japanese Published Unexamined Patent Application No. 2002-71452 discloses a thermal infrared detector having a similar bolometer thin film. In order to suppress the drift of the output of the detector due to an environmental temperature and self-heating of the detector, this thermal infrared detector comprises a first temperature detector and a second temperature detector at each of pixels arranged in an array, and both of the temperature detectors have the bolometer thin films which are formed floating from substrate by the beams so that both temperature detectors are thermally separated from the substrate. Eaves are provided so as to extend outward from both ends of the first temperature detector in such a way as not to touch the beams and the second temperature detector. The infrared reflector is formed on an upper layer of the second temperature detector. By setting thermal capacities of the eaves and the infrared reflector approximately equal to each other, the influence of the temperature change due to the environmental temperature and the self-heating of both temperature detectors is cancelled, so that only signals originated from infrared rays made incident on the first temperature detector and the eaves are taken out.
However, these conventional infrared detectors have problems as follows. It is generally known that an imaging device which images a subject with light receiving elements suffers a phenomenon that the image of a certain object imaged is also observed even after the object has been removed (the phenomenon will hereinafter be referred to as an afterimage) due to the characteristic of light receiving elements or the characteristic of a signal processing circuit. It is also known that with the use of the bolometer infrared detector 1, an afterimage appears at a place where an object with a certain temperature, especially a high temperature, is imaged. The time when the afterimage appears depends on the temperature of the high temperature object and the imaging time of the high temperature object. When a high temperature object of about 500 K is imaged for about 3 minutes, for example, several minutes are required for the level of the afterimage to become equal to or less than the NETD (Noise Equivalent Temperature Difference), raising a serious problem for a system which acquires a heat image in real time. Therefore, there is a demand for a bolometer infrared detector 1 which can reduce an afterimage.

Bolometer infrared detector and afterimage reduction method


The invention relates to a variable-length error-correcting (VLEC) code construction method, in which the main steps are: defining all the needed parameters, generating a code having a fixed length L1, storing in a set W thus obtained all the possible L1-tuples dista22nt of the minimum diverging distance d ‘min! from the codewords (one extra-bit being affixed at the end of all words if the new set W thus obtained is not empty), deleting all words of W that do not satisfy a distance criterion with all codewords, and verifying that all words of the final set W satisfy another distance criterion. Assuming that all distributions of number of codewords for the best VLEC codes have a similar curve allure of a bell shape type, it is then proposed, according to the invention, to define an optimal length value Lm until which the number of codewords increases with their length, whereas it decreases after said value Lm. According to this new construction method, called Lm optimization, it is possible to apply the so-called “Ls optimization” method with avoiding the edges of the curve and to work locally, wherein Ls represents a length to which the thod skips back in the codeword deletion stage.

A classical communication chain, illustrated in FIG. 1, comprises, for coding the signals coming from a source S, a source coder 1 (SCOD) followed by a channel coder 2 (CCOD) and, after the transmission of the coded signals thus obtained through a channel 3, a channel decoder 4 (CDEC) and a source decoder 5 (SDEC). The decoded signals are intended to be sent towards a receiver. Variable-length codes (VLC) are classically used in source coding for their compression capabilities, and the associated channel coding techniques combat the effects of the real transmission channel (such as fading, noise, etc.). However, since source coding is intended to remove redundancy and channel coding to re-introduce it, it has been investigated how to efficiently coordinate these techniques in order to improve the overall system while keeping the complexity at an acceptable level.
Among the solutions proposed in such an approach, the variable-length error correcting (VLEC) codes present the advantage to be variable-length while providing error correction capabilities, but building these codes is rather time consuming for short alphabets (and become even prohibitive for higher length alphabets sources), and the construction complexity is also a drawback, as it will be seen.
First, some definitions and properties of the classical VLC must be recalled. A code C is a set of S codewords {c1, c2, c3, . . . , ci, . . . cS}, for each of which a length li=|ci| is defined, with l1≦l2≦l3≦ . . . ≦li≦ . . . ≦lS without any loss of generality. The number of different codeword lengths in the code C is called R, with obviously R≦S, and these lengths are denoted as L1, L2, L3, . . . , Li, . . . LR, with L1<L2<L3< . . . <LR. A variable-length code, or VLC, is then the structure denoted by (s1@L1, s2@ L2, s3@ L3, . . . , sR@ LR), which corresponds to s1 codewords of length L1, s2 codewords of length L2, s3 codewords of length L3, . . . , and sR codewords of length LR. When using a VLC, the compression efficiency, for a given source, is related to the number of bits necessary to transmit symbols from said source. The measure used to estimate this efficiency is often the average length AL of the code, i.e. the average number of bits needed to transmit a word, and said average length is given, when each symbol ai is mapped to the codeword ci, by the following relation (1):
                    AL        =                              ∑                          i              =              1                                      i              =              s                                                                    l              i                        ·                          P                                            (                                  a                  i                                )                                                                        (        1        )            which is equivalent to the relation (2):
                    AL        =                              ∑                          i              =              1                        R                                                        L              i                        ·                          (                                                ∑                                      j                    =                                                                  r                                                                          (                          i                          )                                                                    +                      1                                                                            j                    =                                          r                                                                    (                                                  i                          +                          1                                                )                                                                                P                                                        (                                          a                      i                                        )                                                              )                                                          (        2        )            where, for a data source A, the S source symbols are denoted by {a1, a2, a3, . . . , aS} and P(ai) is the respective probability of occurrence of each of these symbols, with ΣP(ai)=1 (from i=1 to i=S). If ALmin denotes the minimal value for the average length AL, it is easy to see that when ALmin, is reached, the symbols are indexed in such a way that P(a1)≧P(a2)≧P(a3)≧ . . . ≧P(ai)≧ . . . P(aS). In order to encode the data in such a way that the receiver can decode the coded information, the VLC must satisfy the following properties: to be non-singular (all the codewords are distinct, i.e. no more than one source symbol is allocated to one codeword) and to be uniquely decodable (i.e. it is possible to map any string of codewords unambiguously back to the correct source symbols, without any error).
An introduction and a presentation of different distances that are useful when reviewing some general properties of the VLC codes will then help to recall the notion of error-correcting property used in the VLEC code theory:
(a) Hamming weight and distance: if w is a word of length n with w=(w1, w2, . . . , wn), the Hamming weight of w, or simply weight, is the number W(w) of non-zero symbols in w:
                              W                                (            w            )                          =                              ∑                          i              =              1                                      i              =              n                                                                    w              i                                                                    w                i                                                                                      (        3        )            and, if w1 and w2 are two words of equal length n with wi=(wi1, wi2, wi3, . . . , win) and i=1 or 2, the Hamming distance (or, simply, distance) between w1 and w2 is the number of positions in which w1 and w2 differ (for example, for the binary case, it is easy to see that:H(w1,w2)=W(w1+w2)  (4)where the addition is modulo-2). However, the Hamming distance is by definition restricted to fixed-length codes, and other definitions will be defined before considering VLEC codes.
(b) let fi=w1i w2i . . . wni be a concatenation of n words of a VLEC code C, then the set FN={fi:|fi|=N} is called the extended code of C of order N.
(c) minimum block distance and overall minimum block distance: the minimum block distance bk associated to the codeword length Lk of a VLEC code C is defined as the minimum Hamming distance between all distinct codewords of C with the same length Lk:bk=min{H(ci,cj):ci,cj∈C,i≠,|ci|=|cj|=Lk} for k=1, . . . ,R  (5)and the overall minimum block distance bmin of said VLEC code C, which is the minimum block distance value for every possible length Lk, is defined by:bmin=min{bk:k=1, . . . R}  (6)
(d) diverging distance and minimum diverging distance: the diverging distance between two codewords of different length ci=xi1xi2 . . . xili and cj=xj1 xj2 . . . xjl1 of a VLEC code C, where ci, cj∈ C, li=|cj| and lj=|cj| with li>lj, is defined by:D(ci,cj)=H(xi1xi2 . . . xili,xj1xj2 . . . xjlj)  (7)i.e. it is also the Hamming distance between a lj-length codeword and the lj-length prefix of a longer codeword, and the minimum diverging distance dmin of said VLEC code C is the minimum value of all the diverging distances between all possible couples of codewords of C of unequal length:dmin=min{D(ci,cj):ci,cj∈C,|ci|≠|cj|}  (8)
(e) converging distance and minimum converging distance: the converging distance between two codewords of different length ci=xi1 xi2 . . . xili and cj=xj1 xj2 . . . xjli of a VLEC code C, where |ci|=li>|cj|=lj, is defined by:C(ci,cj)=H(xili−lj=1xili−lj=2 . . . xili,xj1xj2 . . . xjlj)  (9)i.e. it is also the Hamming distance between a lj-length codeword and the lj-length suffix of a longer codeword, and the minimum converging distance of said VLEC code C is the minimum value of all the converging distances between all possible couples of C of unequal length:cmin=min{C(ci,cj):ci,cj∈C,|ci|≠|cj|}  (10)
(f) free distance: the free distance dfree of a code is the minimum Hamming distance in the set of all arbitrary long paths that diverge from some common state Si and converge again in another common state Sj, with j>i:dfree=min{H(fi,fj):fi,fj∈FN,N=1,2, . . . ,∞}  (11)
Following the structure model used for a VLC, it is therefore possible to describe the structure of the VLEC code C by the notation:S1@L1,b1;S2@L2,b2; . . . ;SR@LR,bR;dmin,cmin  (12)where there are si codewords of length Li with minimum block distance bi, for all i=1, 2, . . . R, (it is recalled that R is the number of different codeword lengths) and minimum diverging and converging distances dmin and cmin. The most important parameter of a VLEC code is its free distance dfree, which influences greatly its performance in terms of error-correcting capabilities, and it can be shown that the free distance of a VLEC code is bounded by:dfree≧min(bmin,dmin+cmin)  (13)
These definitions being recalled, the state-of-the-art in VLEC codes construction will be now described more easily. The first types of VLEC codes, called α-prompt codes and introduced in 1974, and an extension of this family, called αt1,t2, . . . , tR-prompt codes, have both the same essential property: if one denotes by α(ci) the set of words that are closer to ci than to any codeword cj, with j≠i, no sequence in α(ci) is a prefix of a sequence in another α(ci). The construction of these codes is very simple, and the construction algorithm is adjustable by the number of codewords at each length, which makes possible to find the best prompt code for a given source and a given dfree. However, this best code performs poorly in terms of compression performance.
A more recent construction, allowing the construction of a VLEC code from the generator matrix of a fixed-length linear block code, was proposed in the document "Variable-length error-correcting codes" by V. Buttigieg, Ph.D. Thesis, University of Manchester, England, 1995. Called code-anticode construction, this algorithm relies on line combinations and column permutations to form an anticode at the rightmost column. Once the code-anticode generator matrix is obtained, the VLEC code is simply obtained by a matrix multiplication.
This technique has however several drawbacks. First, there is no explicit method to find the needed line combinations and column permutations to obtain the anticode. Moreover, the construction does not take into account the source statistics and, consequently, often reveals itself sub-optimal (one can find a code with smaller average length by a post-processing on the VLEC code). In the same document, the author has then proposed an improved method, called Heuristic method, that is based on a computer search for building a VLEC code giving the better known compression rate for a specified source and a given protection against errors, i.e. a code C with specified overall minimum block, diverging and converging distances (and hence a minimum value for dfree) and with codeword lengths matched to the source statistics so as to obtain a minimum average codeword length for the chosen free distance and the specified source (in practice, one takes: bmin=dmin+cmin=dfree, and: dmin=[dfree/2].
The main steps of this Heuristic method, which uses the following parameters: minimum length L1 of codewords, maximum length Lmax of codewords, free distance dfree between each codeword, number S of codewords required, are now described with reference to the flowcharts of FIGS. 2 to 4.
To start the computer search ("Start"), all the needed parameters must be first specified: L1 (the minimum codeword length, which must be at least equal to or greater than the minimum diverging distance required), Lmax (the maximum codeword length), the different distances between codewords (dfree, bmin, dmin, cmin), and S (the number of codewords required by the given source), and some relations are set when choosing these parameters:Ll≧dmin bmin=dfree dmin+cmin=dfree
The first phase of the algorithm, referenced 11, is then performed: it consists in the generation of a fixed length code (put initially in C) of length L1 and minimal distance bmin, with a maximum number of codewords. This phase is in fact an initialization, performed for instance by means of an algorithm such as the greedy algorithm (GA), presented in FIG. 5, or the majority voting algorithm (MVA), presented in FIG. 7, or a new proposed variation, denoted by GAS (Greedy Algorithm by Step), which consists of a variation of the two above mentioned ones. The GAS consists in the search method used in the GA, where instead of deleting half of the codewords, only the last codeword of the group is deleted. These two algorithms are useful to create a set W of n-bit long words distant of d (in practice, it may be noted that the MVA finds more words than the GA, but it asks too much time for only a small improvement of the compression capacity, as shown in the tables of FIGS. 6 and 8, which compare, respectively for the GA and for the MVA, the best code structures obtained with different values of dfree for the 26-symbol English source defined in the table of FIG. 9.
The second phase of the algorithm, corresponding to the elements referenced 21 to 24 (21+22=operation "A0"; 23+24=operation "A2") in FIG. 2, consists in listing and storing (step 21) in a set called W all the possible L1-tuples at the distance of dmin from the codewords in C. If dmin≧bmin, then W is empty. If this set W of all the words satisfying the minimum diverging distance to the current code is not empty (reply NO to the test 22: |w|=0?), the number of words in W is doubled by increasing the length of the words by one bit by affixing first a "0" and then a "1" to the rightmost position of all the words in W (step 24), except if the maximum number of bits is exceeded (reply YES to the test 23). At the output of said step 24, this modified set W has twice more words than the previous W, and the length of each one is L1+1.
The third phase of the algorithm, corresponding to the elements 31 to 35 (=operation "A3" in FIG. 2), consists in deleting (step 31) all the words of set W that do not satisfy the cmin distance (minimum converging distance) with all the codewords of C (i.e. in keeping and storing in a new W only the words which satisfy said minimum converging distance, the other ones being discarded). At this point, the new set W is a set of words which, when compared to the codewords of C, satisfy the required minimum diverging and converging distances (both dmin and cmin distances) with the codewords of C. If that new set W is not empty (reply NO to the test 32: |W|=0?) one selects in W (step 33) the maximum number of words to satisfy the minimum block distance, in order to ensure that all the words of the set W, being of the same length, have a minimum distance at least equal to bmin. At the end of this step 33, realized with the GA or the MVA (note that in this case, the initial set used for the GA or the MVA is the current W and not a n-tuples set), the words thus obtained are added (step 34) to the codewords already in C.
If no word is found (i.e. W is empty) at the end of the step 21 (reply YES to the test 22: |W|=0?) or if the maximum number of bits is reached or exceeded (reply YES to the test 23), one enters the fourth phase of the algorithm (steps 41 to 46, illustrated in FIG. 3 and also designated by the operation "A1" in said figure), which is used in order to unjam the process by inserting more liberty of choice, more particularly by affixing to all words in W extra bits (several bits at the same time) such that the new group contains more bits than the old one. If there are enough codewords in the last group (successive tests 41 and 42, for verifying the number of codewords in the last group, and if there are previous groups), some of them are deleted from said group (as described above), such deletions allowing to reduce the distance constraint and to find more codewords than before. As a matter of fact, the classical Heuristic method thus described begins with the maximum of codewords with the short length, maps them with the high probability symbols and tries to obtain a good compression rate, but sometimes the size of the small lengths sets are incompatible with the required number of codewords S. In this optic, easing a few codewords provides more freedom degrees and allows to reach a position where the initial requirements on distance and number of symbols for the code can be met. This deletion process is repeated until it remains a maximum of one codeword for each length. If W is empty at the end of the step 31 (reply YES to the test 32: |W|=0?), the steps 23, 24, 31, 32 are repeated. If the required number of codewords has not been reached (reply NO to the test 35 provided at the end of this third phase), the steps 21 to 24 and 31 to 35 must be repeated until said steps find that either there are no further possible words to be found or the required number of codewords is reached.
If said required number of codewords has been reached (i.e. the number of codewords of C is equal to or greater than S (reply YES to the test 35), the structure of the VLEC code thus obtained is used in a fifth part, including the steps 51 to 56 (illustrated in FIG. 4, and also designated by the operation "A4" in said figure), in order to calculate the average length AL. This is done by weighting each codeword length with the probability of the source, and comparing it to the current best one. If said average length AL of this VLEC code is lower than the minimized value of AL (=ALmin), this AL becomes the ALmin, and this new AL value and the corresponding code structure are kept in the memory (step 51). These steps 51 and following (fifth part; operation "A4") allow to come back, within the algorithm, towards previous groups, while the other phases of said algorithm are always performed on the current group. The stepsize for such a feedback operation is one, i.e. this feedback action can be considered as exhaustive.
To continue this search of the best VLEC code, it is necessary to avoid keeping the same structure, which would lead to a loop in the algorithm. The last added group of the current code is deleted (steps 52, 53), the deletion of shorter length codewords allowing to find more longer length codewords (test 54: number of codewords in group greater than 1?), and some codewords (half the amount for the GVA; the "best" one for the MVA) of the previous group are deleted (step 55), in order to re-loop (step 56) the algorithm at the beginning of the step 21 (see FIG. 2) and find different VLEC structures (the number of deleted codewords depends on which method is used for selecting the words: if the GA method is used and one wants to obtain a linear code, it is necessary to delete half of the codewords, while with the MVA method only one codeword, the best one, is deleted, i.e. the one that allows to find the more codewords in the next group).
However, the Heuristic method thus described often considers very unlikely code structures or proceeds with such a care (in order not to miss anything) that a great complexity is observed in the implementation of said method, which moreover is rather time consuming and can thus become prohibitive. It has therefore been proposed, in a European patent application filed on Oct. 23, 2002, with the filing number 02292624.0 (PHFR020110), an improved construction method with which it is possible to gain in complexity by avoiding these drawbacks, said method of building a variable length error code comprising, more precisely, the steps of:
(1) initializing the needed parameters: minimum and maximum length of codewords L1 and Lmax respectively, dfree distance de between each codeword (said distance dfree being for a VLEC code C the minimum Hamming distance in the set of all arbitrary extended codes), required number of codewords S;
(2) generating (step 11) a fixed length code C of length L1 and minimal distance bmin, with bmin=min{bk; k=1, 2, . . . , R}, bk=the distance associated to the codeword length Lk of code C and defined as the minimum Hamming distance between all codewords of C with length Lk, and R=the number of different codeword lengths in C, said generating step 11 creating a set W of n-bit long words distant of d;
(3) listing and storing (step 21) in the set W all the possible L1-tuples at the distance of dmin from the codewords of C (said distance dmin for a VLEC code C being the minimum value of all the diverging distances between all possible couples of different-length codewords of C), and, if said set W is not empty, doubling the number of words in W by affixing at the end of all words one extra bit, said storing step therefore replacing the set W by a new one having twice more words than the previous one and the length of each one of these words being L1+1;
(4) deleting (step 31) all the words of the set W that do not satisfy the cmin distance with all codewords of C, said distance Cmin being the minimum converging distance of the code C;
(5) in the case where no word is found or the maximum number of bits is reached, reducing (step 41) the constraint of distance for finding more words;
(6) controlling that all words of the set W are distant of bmin, the found words being then added to the code C (step 34);
(7) if (step 35) the required number of codewords has not been reached, repeating the steps (1) to (6) (i.e. the steps 21 to 35) until the method finds either no further possibility to continue or the required number of codewords;
(8) if the number of codewords of C is greater than S, calculating (operation A4), on the basis of the structure of the VLEC code, the average length AL obtained by weighting each codeword length with the probability of the source, said AL becoming the ALmin, if it is lower than ALmin, with ALmin=the minimum value of AL, and the corresponding code structure being kept in memory;
said building method being moreover such that at most one bit is added at the end of each word of the set W.
Simulations show that, with the classical Heuristic method, almost none of the obtained best codes has a hole (i.e. a length jump in its structure length). It is then considered, in the previously cited European patent application, that most good codes do not have jump of length and, therefore, that the set of examined VLEC codes can be reduced accordingly (which reduces the simulation time and the complexity of implementation of the method, without modifying much the AL). Following this hypothesis, the method has been, according to said European patent application, modified by avoiding to add more than one bit at the end of each word of the set W. The corresponding implementation (improved Heuristic construction method, also called "noHole optimization" method) is illustrated in FIGS. 10 and 11, which show the two parts of a flowchart corresponding to said method (the elements that are identical to the ones observed in FIGS. 2 to 4 being designated with the same references). With respect to the flowchart of FIGS. 2 to 4, the parts that, with respect to the classical Heuristic technique, are useless for the implementation of the improved method have been cancelled:
(a) if W is empty at the end of the step 31 (reply YES to the test 32: |W|=0?), the next phase is now (see FIG. 10) not the repetition of the steps (23, 24, 31, 32), but, according to said "noHole" method, the establishment (in place of said repetition) of a direct connection 91 towards the input of the circuit carrying out the operation 55 (deletion of some codewords, or of the best one, before a repetition of the steps 21 to 24 and 31 to 35), said operation 55 being then, as previously, followed by the operations 21 and following.
(b) the fourth phase of the method is now reduced to one step, the operation 41, which is the test "Number of codewords in last group=1?". If the reply is NO, a direct link is established with the input of the step 55 (connection 91), in view of carrying out said operation 55, and then the operations 21 and following. If the reply is YES, a connection 92 is established with the input of the set of operations 52 to 54.
The results thus obtained are presented in the table of FIG. 12 for the 26 symbol English source when using the GAS method for selecting codewords. It can be seen, when comparing with results presented in FIG. 13, that although the result is not completely optimal for dfree=3 (the code structure has a hole at length L=11), the AL rise is really acceptable when one considers that there is both strictly no degradation for the other dfree values and a gain of time between 2, 5 and 4. The same remarks can be applied when comparing the present solution with the ones obtained in FIG. 7, where the MVA complexity effect is clear. Similarly, applying the noHole optimisation with the GA method for selecting codewords leads to a time gain at the only expense of a slight AL rise for dfree=3. Finally, FIG. 5 shows on the other hand that the current solution offers better AL for an acceptable gain of time, the noHole optimisation compensating almost entirely the complexity induced by the GAS.
However, with the method thus described in said European patent application, there are cases where there are too many small length codewords in the generated VLEC code. It has then been proposed, in another European patent application filed on Mar. 11, 2003, with the filing number 03290604.2 (PHFR030026), another improved building method according to which the group deletion is not only performed with the last obtained codewords group, but more generally with groups up to a given length value group, in order to make possible to go back directly, and therefore very quickly, to smaller lengths, i.e. to skip many algorithm steps in cases where there are too many small length codewords. More precisely, denoting by Ls (with s for: skip) the length to which the algorithm will skip back to in the codeword deletion stage, it has been proposed to skip parts of the original Heuristic algorithm by carefully jumping to lower lengths when looking for codewords to be deleted (however, when the considered codewords group length L is smaller than a preset value Ls, it is obviously better to apply the previous method, and the deletion is then done within the group of length L). The length comprised between L1 and Ls are consequently called "free lengths", i.e. lengths with a freedom degree, as they are decremented one by one in the search process (when the number of free lengths grows up, the simulation time also increased, exponentially). This method, called "Ls optimization adding", is depicted in the flowchart formed by the association of FIG. 10 (unchanged part of the previous method, the so-called noHole optimization method) and FIG. 14 (modified part of the noHole optimization method).
Said FIG. 14 is adapted from FIG. 11 according to the following indications. The last added group of the current code is deleted, but only if (test 61) the codeword length of this previous group is (reply NO to the test 61) lower than or equal to Ls (the steps that follow the test 61 are then the same as previously: steps 53, 54, and 55 or 52 at the output of the test 54). If said codeword length is greater than Ls (reply YES to the test 61), an additional step 62 is provided for going to group with Ls-bit long codewords and deleting all groups with more than Ls bits. At the output of the step 62, the same steps 54, 55 as previously are provided. In practice, simulation results show that good compression rates can be obtained for Ls<L(max), where L(max) is the maximal authorized codeword length (it can be noted that increasing the value of Ls results in an improvement of the AL value until a constant floor—the best value—is reached, and this behaviour then suggests a possible dynamic choice of Ls, starting with Ls=L1 and incrementing it until said floor is reached). It seems however that, unfortunately, said Ls optimization method may be not consequent enough to decrease the computation time in all situations.

Method and device for building a variable length error-correcting code


A plural sided cleaning article optionally removably attachable to a handle. The cleaning article may have a layered construction. The construction may comprise a sheet, to accommodate optional and removable attachment to a handle, intermediate tow fibers, and a non-planar structure extending outwardly from the side of the tow fibers opposite the sheet. This arrangement avoids the disadvantage of strips according to the prior art while increasing the surface area of the tow fibers.

Various cleaning articles have been created for dusting and light cleaning. For example, cloth rags and paper towels used dry or wetted with polishing and cleaning compositions have been used on relatively flat surfaces. But, rags and paper towels are problematic for reasons such as hygiene (the user's hand may touch chemicals, dirt or the surface during cleaning), reach (it may be difficult to insert the user's hand with the rag or paper towel into hard-to-reach places) and inconvenience (cleaning between closely-spaced articles typically requires moving the articles).
To overcome the problems associated with using rags and paper towels, various dust gathering devices having feathers, lamb's wool, and synthetic fibers brushes have been utilized for more than a century, as illustrated by U.S. Pat. No. 823,725 issued in 1906 to Hayden. Such dust gathering devices can be expensive to manufacture, and as such are designed to be cleaned and reused. One problem associated with a reusable dust gathering device is that such dust gathering devices may not hold or trap dust very well. Soiled, reusable devices are typically cleaned via shaking or through other mechanical agitation. This process is not entirely satisfactory as it requires an extra step during, interrupting and/or following the cleaning process. Furthermore, the attempted restoration of the device may not be successful, allowing redeposition of the previously collected dust.
To address the problems experienced with reusable dust gathering devices, disposable dust gathering devices have been developed which have limited re-usability. These disposable dust gathering devices may include brush portions made of synthetic fiber bundles, called tow fibers, attached to a nonwoven sheet. The disposable cleaning article may be used for one job (several square meters of surface) and discarded, or may be restored and re-used for more jobs, then discarded. Traditional cleaning articles including feather dusters, cloths, string mops, strip mops and the like, are not disposable for purposes of this invention.
Such devices may be made, for example, according to U.S. Pat. Nos. 6,813,801; 6,968,591; 6,984,615; 7,228,587; 7,231,685; 7,234,193; 7,234,914; 7,237,296; 7,237,297; 7,243,391; 7,302,729; 7,302,730; and/or 7,334,287 (having a common related application). The patents in this linage have a common feature—strips laterally extending from both sides of a generally planar article. The strips serve the purpose of increasing surface area of intermediate tow fibers by promoting deformation of the tow fibers out of the plane of the article. This approach has the attendant problem that excessive material is used for the strips. If the strips have the same length, taken from the longitudinal axis, as the tow fibers, the strips can interfere with the tow fibers fully contacting the target surface.
The problem of strips in such cleaning articles is exacerbated in U.S. Pat. No. 5,953,784 which teaches strips extending not only from both sides of the cloth, but also from the front. One attempt to overcome this problem is found in U.S. Pat. No. 7,566,671 which does not use laterally extending strips. However, this attempt has the drawback that the cleaning implement thereof only cleans on one side of the implement—not both as taught by the lineage of U.S. Pat. No. 6,813,801.
An attempt to overcome the single-sided cleaning disadvantage of the aforementioned U.S. Pat. No. 7,566,671 is found in U.S. Pat. No. 7,251,851 which teaches a spiral duster. However, this approach starts with a construction similar to that of the aforementioned U.S. Pat. No. 6,813,801 lineage and U.S. Pat. No. 823,725—leading the intended solution back to the same approach which started the problem 100 years ago.
Thus, there is a need for a two-sided cleaning article which uses less material than found in the known art. The need further must provide for advantageous use of the tow fibers to gather and retain dust.

Cleaning article with non-planar element in place of strips


A method and apparatus for detecting the level of red blood cells, plasma or serum, and organic separation gel in a test tube covered with multiple labels is provided. Visible and infrared light beams are projected onto a test tube. The portions of the light beams that pass through the test tube are detected as a function of position along the vertical axis of the test tube. The levels of the interfaces are then calculated from the detected portions.

When a test tube containing a blood sample arrives at a laboratory where tests are to be performed on the sample, it must be determined whether there is a large enough sample to conduct the ordered tests. More specifically, after the sample is separated in a centrifuge, it is necessary to determine the amount of red blood cells and serum or plasma, in the sample.
Sometimes, organic separation gel is added into the tube in order to store the sample. The gel provides a hydrophobic barrier between the serum and the red blood cells and thereby prevents the red blood cells from metabolizing the components of the serum. Therefore, it is also necessary to determine if gel is present in the sample.
These tasks are traditionally performed by visual inspection. However, generally, before the test tube arrives at the laboratory, many labels are placed on the test tube. Several layers of labels make visual inspection very time consuming and difficult, if not impossible. Accordingly, there is a need to easily, quickly, inexpensively, reliably, and safely determine if there is a large enough sample present in a test tube that is covered in labels to conduct required tests.
The present invention meets this need by providing a method for detecting interfaces in a container made up of a material and having a vertical axis and containing an upper layer of serum or plasma and a lower layer of cells. The container can also contain a middle layer of gel and have a cap. The container can be a test tube made up of plastic or glass.
A first detecting light beam, which is substantially transmitted by serum, plasma, labels and the material but substantially blocked by the cells, is projected onto the container. A portion of the first detecting light beam is transmitted through the container. A second detecting light beam, which is substantially blocked by serum, plasma, and cells, but substantially transmitted by the material and labels, is also projected onto the container. A portion of the second detecting light beam is transmitted through the container. Lasers, either directly or through fiber optic cables, can project the light beams.
Then, the portion of the first detecting light beam that is transmitted through the container and no significant portion of the second detecting light beam is detected as a function of position along the vertical axis of the container. Likewise, the portion of the second detecting light beam that is transmitted through the container and no significant portion of the first detecting light beam is detected as a function of position along the vertical axis of the container. Then, the location of interfaces is determined from the detected portions.
The first and second detecting light beams can be projected by respective projectors, and detected by respective detectors. The light beams preferably are substantially perpendicular to the longitudinal axis of the container, and can be coplanar.
The present invention further provides an apparatus for detecting the location of at least one interface in a container made up of a material and having a vertical axis and containing an upper layer of serum or plasma and a lower layer of cells. A first projector projects onto the container a first detecting light beam that is substantially transmitted by serum and plasma and the material but is substantially blocked by the cells. A portion of the first detecting light beam is transmitted through the container. A second projector projects onto the container a second detecting light beam that is substantially blocked by serum, plasma, and cells, but is substantially transmitted by the material. A portion of the second detecting light beam is transmitted through the container.
A first detector detects, as a function of position along the vertical axis of the container, the portion of the first detecting light beam that is transmitted through the container. A second detector detects, as a function of position along the vertical axis of the container, the portion of the second detecting light beam that is transmitted through the container. A processor is operably attached to the detectors and determines the location of interfaces from the detected portions.


An associative-memory-storage unit, and to an associative-memory-storage method are provided. The associative-memory-storage unit includes a first subset of at least memory sub-units over w bits, and a second memory sub-unit over v bits. The associative-memory-storage sub-unit may be used to associate messages with labels, and vice versa.

Human memory is fundamentally associative: we remember better when we are able to link the new information to knowledge that has already been acquired and that is solidly anchored in our memory. Furthermore, the greater the meaning it has for us, the more effective this link will be. Rather than simple recall of fixed impressions, memory is therefore at the present time considered to be a continual process of re-categorization stemming from a continuous change in antagonistic neuronal pathways and from parallel processing of information in the brain.
Technology is attempting to copy these processes mainly using the electronic method referred to as associative memory or content-addressable memory (CAM). A review of the literature has been published in the publication K. Pagiamtzis et A. Sheikholeslami, "Content-addressable memory (CAM) circuits and architectures: A tutorial and survey" IEEE Journal of Solid-State Circuits, vol. 41, no. 3, pp. 712-727, March 2006.
This storage mechanism has become non-volatile with the appearance of MRAM (Magnetic Random Access Memory) memories in which data are stored in the form of a magnetic orientation. The change of state is achieved by changing the spin of the electrons (in particular by tunneling). These components are sold by Everspin inter alia.
In France, an MRAM technology has been codeveloped by the laboratory Spintec of the CNRS and the company Crocus Technology in Grenoble. It is based on an innovative programming technique that allows limitations with respect to stability and miniaturization to be overcome. Instead of the conventional stacks of ferromagnetic layers, these partners have developed a memory cell that associates a ferromagnetic layer with an antiferromagnetic layer that is more stable with temperature. This cell is combined with a self-referenced memory cell technology that allows a comparison logic function called Match-In-Place to be integrated directly into the memory plane. Patent U.S. Pat. No. 9,401,208 B2 "Magnetic random access memory cell with a dual junction for ternary content addressable memory applications" of the same company describes the integration of a ternary mode: the ternary CAM allows one or more bits in the given stored word to be programmed to a third state, referred to as "X", or "don't care" in the above patent, allowing the flexibility of the search to be increased. For example, a ternary CAM could have a stored word of "10XX0", which would correspond to searches for any of the words "10000", "10010", "10100" and "10110".
This memory cell is of STT-MRAM type (STT-MRAM standing for spin-transfer torque magnetic RAM). Its dimensions permit large-scale, low-cost integration, a very low power consumption and the guarantee of a very long retention of information.
Another type of non-volatile memory, called N-RAM for Nano-RAM, which is the fruit of research carried out by Nantero, an American firm, is currently emerging. It uses the characteristics of carbon nanotubes, which allow the size of a chip to be considerably decreased and therefore the capacity of a module to be increased. This type of memory is described in patent No. U.S. Pat. No. 9,299,430 B1 "Method for reading and programming 1-R resistive charge element arrays" of this firm.
This cell is composed of a certain number of nanotubes suspended above an electrode. When a current passes between the two electrodes, the nanotubes are attracted to the upper electrode and make contact therewith. In the case where there is no current between the two electrodes, the carbon nanotubes remain suspended in the air. To determine whether the nanotubes are touching the upper electrode or not, a voltage is deployed between a terminal and the upper electrode. If a current passes, this means that the nanotubes are making contact with the upper electrode and the value 1 is returned. If a current does not pass, the nanotubes are suspended and the value 0 is returned. The values 0 and 1 are therefore so-called stable positions, because there is no mechanical tension on the nanotubes. This architecture is more favorable to decrease in etch pitch than DRAM and requires less current to write data while having similar speeds to SRAM.
Another non-volatile memory technique based on a hafnium-oxide ferroelectric, and described in patent U.S. Pat. No. 7,709,359, is very promising because of its small cell size, about 10F2, of the fact that its consumption in write mode is at least 1000 times lower than that of STT-MRAM, and of its fabrication compatibility with CMOS technology (both in terms of etching scale and in terms of process compatibility).
These technologies have given rise to several developments published in the field of neuronal sciences, including that of:    V. Gripon and C. Berrou, "Sparse neural networks with large learning diversity," IEEE trans. on Neural Networks, vol. 22, n 7, pp. 1087-1096, July 2011. This article gives a definition of:            learning diversity enabled by data sparsity given an amount of stored information M, in the following description: equal to 2v with an amount of code corresponding to the sub-message I=2w, le message k consisting of c sub-messages (in the following description: a message ME consists of n sub-messages). The length of the message ME is therefore n times w bits and the diversity of the storage mechanism is 2n+w.
The density d which, for a value of M>>c (here 2v>>n˜8) and M<<I2 (here 2v<<2n+w) is close to M/I2, i.e. in the following description:d=2v/22+w or 2v−(2+w).
This density must be low in order to avoid confusion of the learnt messages corresponding to the admissible error rate: with the values of v=16 and w=24, d=2−10, i.e. an error rate close to 0.001.
Associated with this article, the authors have filed two patents: FR2964222A1 and FR2980876A1 describing a neuronal device using these principles.    Hooman Jarollahi, Vincent Gripon, Naoya Onizawa, and Warren J. Gross "A low-power Content-Addressable Memory based on clustered-sparse networks" ASAP, 2013 IEEE 24th int. conference.    F. Leduc-Primeau, V. Gripon, M. G. Rabbat, and W. J. Gross, "Clusterbased associative memories built from unreliable storage" in Proc. Of IEEE Intl. Conf. on Acoustics, Speech, and Signal Processing (ICASSP), May 2014. Demetrio Ferro, Vincent Gripon, Xiaoran Jiang, "Nearest Neighbour Search Using Binary Neural Networks" International Joint Conference on Neural Networks (IJCNN) 2016.    Qing Guo, Xiaochen Guo, Yuxin Bai, Engin_Ipek, "A Resistive TCAM Accelerator for Data-Intensive Computing" MICRO'11 Dec. 3-7, 2011, Porto Alegre, Brazil et,    Qing Guo, Xiaochen Guo, Ravi Patel, Engin_Ipek, Eby G. Friedman "AC-DIMM: Associative Computing with STT-MRAM", ISCA '2013 Tel-Aviv, Israel, have introduced these associative memory storage mechanisms into an electronic component arranged to form a DIMM-format memory strip, in replacement of the existing ones, and they therefore use the existing bus layout.
All these approaches to associative memory storage do not allow a concomitant operation in the two directions (bottom-up and top-down) that exist in human memory while allowing information to be dynamically fedback. Furthermore, the elements stored in memory are not simply transferable from one medium to another.
Another approach has been suggested by P. Pirim, the author of the present invention, with the aim of overcoming these drawbacks, in a publication: "Perceptive Invariance and Associative Memory Between Perception and Semantic Representation, USER a Universal Semantic Representation Implemented in a System on Chip (SoC)" published in Living Machines 2016, LNAI 9793, pp. 275-287, 2016. This first succinct approach has been followed by many improvements, which are described in this invention. A new associative memory model has been created by integrating new TCAM techniques allowing error correction via a computation of maximum likelihood in a large-scale, low-cost integration.

Automated method and associated device for the non-volatile storage, retrieval and management of message/label associations and vice versa, with maximum likelihood


The present invention relates to a suture which is firmly maintained and fixed to an operation site to stably sustain suturing or lifting effects for a long time. More specifically, the present invention provides a suture having a conic or pyramidal shape with a cut top, wherein a suture supporter comprising a communication hole penetrating the both ends is provided at one end. The suture support can have one or more portions which are cut vertically from a lower end at a lower end portion having a larger diameter between the both ends, or a part of the lower end can be removed so as to form one or more gaps formed from the end at a wall of the end portion.

A suture has been used for a long time to be used to connect and suture damaged muscles, blood vessels, nerves, or tissues and injuries or parts incised due to a surgical operation. In addition, a suture is used for a double eyelid surgery and a medical operation for removing tissues, which are generated due to aging, a decrease in skin elasticity, injuries, overdose, necrosis, or the like, a flabby skin, wrinkles, or the like. A lifting medical operation using a suture is a technology to lift up a flabby skin or tissue such as a face, a chin, a neck, an abdomen, a vagina, a breast, or a hip by using needles and threads instead of using a knife. The lifting medical operation using a suture has attracted much attention because the lifting medical operation does not excessively incise a skin, minimizes generation of scars, and generates less bleeding and swelling due to an operation.
Recently, a suture in which barbs are formed on an external surface thereof has been developed and used. Such a suture is not slipped due to the barbs, and thus the suture is not easily untied after a sutura.
One of points to be considered in an operation using a suture that is firmly maintained and fixed at a part where a surgical operation has been performed, in order to stably maintain suturing and tight adhesion, supporting, and fixing of tissues. In addition, a firm knotting device for allowing a suture not to be untied is required, and also it is necessary to minimize time and efforts on knotting for a rapid and safe operation.
The inventors of the present invention applied for Korean Patent Application Nos. 10-2011-0019895 and 10-2011-0064084 for a suture including a suture supporter not requiring a knotting process, and the contents thereof are introduced in the present specification. The inventors of the present invention have conducted the study in order to invent a more convenient and useful suture.

Knotless suture, and kit containing same


A low profile antenna array for UWB radar antenna applications is disclosed. It may be used as a mid-range receiving antenna array (RXM) or as a mid-range transmitting antenna array (TXM). In some embodiments, the RXM or the TXM may include a plurality of radiation patch elements formed on a top layer of a printed circuit board (PCB), a distribution feeding network in the mid-layer of the PCB having a patch array, and a serial feeding arrangement from a λ/4 coupling slot to each feeding patch. This antenna may have a desirable large frequency bandwidth with relatively flat antenna gain over a frequency range from 22 GHz to 26.5 GHz. In addition, sidelobe levels for the elevation patterns may be below −20 dB. Other embodiments are disclosed and claimed.

1. Field of the Invention
Embodiments of the invention generally relate to the field of radar system antennas, and more specifically to patch antenna arrays suitable for use in ultra-wide-band radar applications.
2. Discussion of Related Art
Radar is used in many applications to detect target objects such as airplanes, military targets, and vehicles. More recently, radar systems have been implemented in automobiles. Automotive radar systems are known for use in helping drivers to park their cars, to follow traffic at a safe distance, and to detect driving obstacles. In such applications, when the radar system detects an obstacle or the slowing down of traffic in front of the vehicle, it may issue a warning to the driver, such as a beep or warning light on the dashboard, and/or actually control the vehicle in some way, such as by applying the brakes, in order to avoid an accident.
For example, a radar system may detect the range (i.e., distance) to a target object by determining the roundtrip delay period between the transmission of a radar signal and the receipt of the signal returning back to the radar after it bounces off of the target object. This round-trip delay, divided in half and then multiplied by the speed of the radiation, c, gives the distance between the radar system and the target object (assuming the transmitting antenna and the receiving antenna are the same antenna or very close to each other).
As can be appreciated, it would be desirable to provide radar antenna structures for automobile applications that can be implemented in a compact volume, and which also can be provided at a low cost.

Antenna array for ultra wide band radar applications


Embodiments of systems and methods for compressing plasma are disclosed in which plasma can be compressed by impact of a projectile on a magnetized plasma in a liquid metal cavity. The projectile can melt in the liquid metal cavity, and liquid metal may be recycled to form new projectiles.

1. Field
The present disclosure relates to embodiments of systems and methods for plasma compression.
2. Description of Related Art
Some systems for compressing plasma to high temperatures and densities typically are large, expensive, and are limited in repetition rate and operational lifetime. The addition of a magnetic field within the plasma is a promising method for improving the effectiveness of any given heating scheme due to decreased particle and energy loss rates from the plasma volume.
Methods of compressing a plasma include the following six schemes.
(1) Direct compression of a plasma using an external magnetic field that increases with time.
(2) Compression by an ablative rocket effect of an outer surface of an implosion capsule, with the compression driven by intense electromagnetic radiation or high energy particle beams (such as certain Inertial Confinement Fusion (ICF) devices). See, for example, R. W. Moir et al., "HYLIFE-II: An approach to a long-lived, first-wall component for inertial fusion power plants," Report Numbers UCRL-JC--117115; CONF-940933-46, Lawrence Livermore National Lab, August 1994, which is hereby incorporated by reference herein in its entirety.
(3) Compression by electromagnetic implosion of a conductive liner, typically metal, driven by large pulsed electric currents flowing in the implosion liner.
(4) Compression by spherical or cylindrical focusing of a large amplitude acoustic pulse in a conducting medium. See, for example, the systems and methods disclosed in U.S. Patent Application Publication Nos. 2006/0198483 and 2006/0198486, each of which is hereby incorporated by reference herein in its entirety. In some implementations, the compression of a conductive medium can be performed using an external pressurized gas. See, for example, the LINUS system described in R. L. Miller and R. A. Krakowski, "Assessment of the slowly-imploding liner (LINUS) fusion reactor concept", Rept. No. LA-UR-80-3071, Los Alamos Scientific Laboratory, Los Alamos, N. Mex. 1980, which is hereby incorporated by reference herein in its entirety.
(5) Passive compression by injecting a moving plasma into a static but conically converging void within a conductive medium, such that the plasma kinetic energy drives compression determined by wall boundary constraints. See, for example, C. W. Hartman et al., "A Compact Torus Fusion Reactor Utilizing a Continuously Generated String of CT's. The CT String Reactor", CTSR Journal of Fusion Energy, vol. 27, pp. 44-48 (2008); and "Acceleration of Spheromak Toruses: Experimental results and fusion applications," UCRL-102074, in Proceedings of 11th US/Japan workshop on field-reversed configurations and compact toroids; 7-9 Nov. 1989; Los Alamos, N. Mex., each of which is hereby incorporated by reference herein in its entirety.
(6) Compression of a plasma driven by the impact of high kinetic energy macroscopic projectiles, for example, by a pair of colliding projectiles, or by a single projectile impacting a stationary target medium. See, for example, U.S. Pat. No. 4,328,070, which is hereby incorporated by reference herein in its entirety. See, also, the above-incorporated paper by C. W. Hartmann et al., "Acceleration of Spheromak Toruses: Experimental results and fusion applications."

Systems and methods for plasma compression with recycling of projectiles


A laundry treating appliance may include a door supporting a wash aid dispenser. The door may be mounted for movement relative to a treating chamber and include a projection extending from a lower portion of the door on a side of the door facing the treating chamber. A wash aid receptacle for holding wash aid chemistry may be provided on the projection for dispensing of the wash aid chemistry into the treating chamber.

Laundry treating appliances, such as a clothes washer, typically use one or more wash aids, such as detergent, fabric softener, bleach, and oxidizers, to treat a load of laundry. The wash aid may be supplied by a user directly into a treating chamber of the laundry appliance or into a wash aid dispenser. Some common locations for the wash aid dispenser may include an opening located under the door and adjacent to the opening for the treating chamber in a vertical axis, top loading appliance and a slidable drawer positioned on the front panel of a horizontal axis, front loading appliance.

Door wash aid dispenser for a laundry treating appliance