A measuring method using a surface acoustic wave device, with which even in a case where a target substance having a different viscosity is added to a buffer liquid on the surface acoustic wave device it is possible to measure a mass load accurately without suffering an effect of this viscous load, and it is also possible to shorten the time taken for the temperature of the buffer liquid to stabilize and thereby shorten the time taken for the measurement. The measuring method provided is a method for exciting a surface acoustic wave on a substrate and measuring a property of a target substance placed on a detecting part on the substrate on the basis of a change in a characteristic of the surface acoustic wave, with the characterizing feature that a viscous load of the target substance is evaluated on the basis of fluctuations of at least two different frequencies among frequencies of the surface acoustic wave excited on the substrate, and a mass load of the target substance is measured by being separated from this viscous load.

This invention relates to a method for exciting a surface acoustic wave on a substrate and measuring a property of a target substance placed on a detection part on the substrate on the basis of change in a characteristic of the surface acoustic wave.
As a method for measuring interactions of biological substances such as DNA and proteins, and for measurements using antigen-antibody reactions, surface acoustic wave devices are being used (see for example JP-A-06-133759 and "A Love wave sensor for (bio)chemical sensing in liquids" Sensors and Actuators A, 43(1994)38-43).
In this measurement using a surface acoustic wave device, either the center frequency f0 of an acoustic wave excited in the device (the point at which the conductance of the measuring system is maximal or the point at which the phase is 0) is measured continuously or the center frequency f0 is measured continuously using a network analyser or the like, and the mass load of the surface acoustic wave device is measured on the basis of fluctuation of this center frequency f0.
Now, when a target substance is placed on the detection part of a surface acoustic wave device for measurement, besides the mass load, a viscous load caused by changes in viscosity affects the center frequency f0, and it has not been possible to distinguish these loads clearly. When an attempt is made to investigate interactions of biological materials such as DNA and proteins or to investigate antigen-antibody reactions on the basis of frequency fluctuations with this kind of measurement system, because the viscosity of the target substance introduced into the measurement system and the viscosity of a buffer liquid used (a biochemical buffer liquid having NaCL or KCl or the like as a main constituent) often differ, it has not been possible to distinguish whether the measured frequency fluctuation is a result of mass load caused by bonding of DNA/proteins or bonding of antigen-antibodies or a result of viscous load, and it has not been possible to make precise measurements. And also because of liquid viscosity changes accompanying liquid temperature changes caused by room temperature changes and the introduction of target substances, sometimes precise measurements have not been possible.

Measuring method using surface acoustic wave device, and surface acoustic wave device and biosensor device


A microstrip antenna configured to wrap around a projectile's body without interfering with the aerodynamic design of the projectile. The microstrip antenna has three identical conformal antenna elements equally spaced around the circumference of the projectile's body. The antenna has an operating frequency of 241.2 MHz or 231.0 MHz, a maximum diameter of ten inches and a maximum length of nine inches.

1. Field of the Invention
The present invention relates generally to a microstrip antenna for use on a weapons system to transmit telemetry data. More specifically, the present invention relates to a TM cylindrical shaped microstrip antenna array which transmits telemetry data and which is adapted for use on a 10-inch diameter weapons system such as a missile.
2. Description of the Prior Art
A microstrip antenna operates by resonating at a frequency. The conventional design uses printed circuit techniques to put a printed copper patch on the top of a layer of dielectric with a ground plane on the bottom of the dielectric. The frequency of operation of the conventional microstrip antenna is for the length of the antenna to be approximately a half-wavelength in the microstrip medium of dielectric below the patch and air above the patch. A quarter-wavelength microstrip antenna is similar to the half wavelength microstrip antenna except the resonant length is a quarter-wavelength and one side of the antenna is grounded.
There is currently a need to produce a quasi omni-directional radiation pattern to the front and rear of the antenna with circular polarization from a conformal wrap-around microstrip antenna with a 10-inch maximum diameter and 9-inch maximum length. The antenna is to be used on a weapons system or projectile such as a missile. The required frequency of operation for the antenna is 241.2 or 231.0 MHz.

The United States of America as represented by the Secretary of the Navy


A wet electrolytic capacitor that contains a casing within which is positioned an anode formed from an anodically oxidized sintered porous body and a fluidic working electrolyte is provided. The casing contains a metal substrate over which is disposed a hydrogen protection layer that contains a plurality of sintered agglomerates formed from a valve metal composition. The present inventors have discovered that through careful selection of the relative particle size and distribution of the agglomerates, the resulting protection layer can effectively absorb and dissipate hydrogen radicals generated during use and/or production of the capacitor, which could otherwise lead to embrittlement and cracking of the metal substrate.

Electrolytic capacitors typically have a larger capacitance per unit volume than certain other types of capacitors, making them valuable in relatively high-current and low-frequency electrical circuits. One type of capacitor that has been developed is a "wet" electrolytic capacitor that includes a sintered tantalum powder anode. These tantalum slugs first undergo an electrochemical oxidation that forms an oxide layer coating acting as dielectric over the entire external and internal surfaces of the tantalum body. The anodized tantalum slugs may then be sealed within a metal casing (e.g., tantalum) containing a liquid electrolyte solution. One problem with wet electrolytic capacitors, however, is that the casing is susceptible to cracking, which can lead to leakage of the electrolyte and a rapid deterioration of electrical performance. A common reason for cracking is hydrogen embrittlement, which can result when the casing absorbs a certain degree of hydrogen radicals produced by the electrolyte. As such, a need still exists for an improved wet electrolytic capacitor that has a reduced susceptibility to hydrogen embrittlement.

Wet electrolytic capacitor containing a hydrogen protection layer


A memory combines plural memory cells for storing data wherein the differential stages voltage levels of memory cells are not limited in square value of 2 and can be improved linearly. The feature of the present invention can also increase memory capacity without increasing memory area. Furthermore it can remain voltage levels which cannot express 0 and 1 combination for error erasure messages when data is read. For efficient usage of memory, the increased memory capacity is not only for storing data but also for storing error correction scheme to assure the veracity of the storing data and improve producing yield and reliability for multilevel memory systems.

1. Field of the Invention
The present invention relates to a method of memory, and more particularly to a method for storing data and information related to data error correction by combining plural memory cells, which can increase memory capacity without extra area penalty.
2. Description of the Prior Art
With digital technology developing, information transmission is not limited by the space any more. Not only far-reaching transmitting on network, data can be also carried about by various memory in portable devices. However, how to assure the data transmitted exactly in transmission procedure becomes a very important job since data has to transmit and convert frequently between different interfaces and storing devices. For various memories often used nowadays, the FIG. 1 refers to their data storing procedure. When inputting a data, an error correction code generator 1 carries on the operation of error correction encoding to the data and generates the redundancy, and then assembles the redundancy to be an error correction code capable of identifying the data. Then, a programming circuit 3 writes data and error correction code into a memory device 5. The error correction code will be used to correct error 7 in the data for assuring that data can be outputted exactly.
In 1965, the cofounder, Gordon Moore, of Intel Corp. predicted that the number of silicon chip transistor had doubled every 18 months, also called "Moore's Law". The memory capacity has been increased from 8M, 16M in the earlier period to 1024M nowadays, the development of memory capacity can be treated as the best witness of Moore's Law. However, it has to overcome many constrictions for achieving the higher capacity in memory cells. Enterprises have to pay more for developing techniques now.
Generally speaking, the technique of increasing memory capacity can be divided in two ways: one is to increase the number of memory cells and the other is to increase capacity of each memory cell using multilevel technique. For example, the characteristic of a multilevel cell is described by a number of curves representing different logic values. FIG. 2 shows the characteristic of a four-level (2-bit) cell which stores the bits "11", "10", "01" and "00" corresponding to different voltage levels. Although the capacity has been doubled, on the other hand, the more differential levels in particular voltage region of memory cells, the more hard to develop techniques. If the growth is limited by value of 2m, it indicates that memories of next generation have to be increased to 8 or even 16 voltage levels for providing 3 bits or 4 bits of each memory cell, respectively. Therefore, the experienced curve of technique development will grow exponentially for getting more voltage levels. The present invention presents an effective grouping of several q-level memory cells with q>2m in order to gaining more memory capacity in a linear manner. It is not only getting more capacity and overcoming the technical difficulties to increase the number of voltage levels in memory cells, but also rendering the present invention having error correction scheme for assuring the veracity of the storing data and improving producing yield and reliability for multilevel memory systems.

Method of combining multilevel memory cells for an error correction scheme


A gas detection system and method selectively detects a gas in the presence of nonselected contaminant gases. The system includes a housing having a collection chamber and a sampling chamber containing a variable resister and a molecular sieve. A molecular sieve is positioned between the chambers for selectively passing a target gas from the collection chamber to the sampling chamber. An organic molecular sieve permits only selected low molecular weight gases, such as ammonia and carbon monoxide to come into contact with the sensor.

1. Field of the Invention
The present invention is broadly concerned with an improved system for selectively detecting low molecular weight gases such as ammonia and carbon monoxide in the presence of a variety of contaminant gases. More particularly, it is concerned with a gas detection system having an organic molecular sieve filter, a semiconductor sensor, an electronic control system, and an alarm. The system of the invention may be used to good effect to continuously monitor for selected low molecular weight gases in hot environments subject to periodic contamination by alcohols, methane, acetic acid, and other nonselected gases.
2. Description of the Related Art
Related art gas detection systems for small molecular weight gases such as ammonia and carbon monoxide lack specificity in that they also recognize a variety of contaminant gases. Such gas detection systems often employ solid state semiconductor gas sensors, broad spectrum devices which are extremely durable and particularly well suited for use in hot environments such as machine rooms. Despite this lack of specificity, in many applications systems employing semiconductor sensors are preferred over those which employ electrochemical sensors, which are more expensive, short lived and may be depleted by a single large gas leak. Such solid state systems are also often preferred over systems employing infrared or ultraviolet light sensors, which are expensive and require complex apparatus to monitor a large area.
For example, ammonia sensors are employed in the food industry, where processing and distributing environments typically include commercial refrigeration systems which employ compressed ammonia gas. Gas detection systems which are currently available to detect leakage of such ammonia refrigerant include sensors which may be tripped by nonammonia-containing gases. Such contaminant gases may emanate from a variety of sources including cleaning chemicals, such as chlorine, ozone, alcohols, and solvents. Alcohol in particular is present in many commercial environments, and heretofore gas detection systems have often been unable to distinguish ammonia gas from alcohols. Other sources of contaminant gases include product off-gassing such as ethylene, and methane gases emanating from food wrappings; use of internal combustion engines, which produce carbon monoxide and unburned hydrocarbons; and air borne, non-gaseous particulate matter such as flour, dust and grease.
In addition, variations in temperature, moisture levels, and air composition, such as low oxygen levels occurring in certain fruit storage areas, may affect the functioning of available gas sensing devices.
Carbon monoxide sensors are employed in both domestic and commercial environments where combustion used to generate heat and air conditioning may also generate toxic gases. Current carbon monoxide gas detection systems may include broad spectrum sensors which may be tripped by other large or small molecular weight gases, a characteristic which increases with the age of the sensor. Maintenance of such systems is expensive and time-consuming, because aging sensors must be replaced at intervals of about every two years in order to compensate for their increased sensitivity. Failure to conduct such frequent maintenance results in false alarms, which may encourage the user to incapacitate the device entirely. In addition, false alarms create the possibility that a true alarm will be ignored.
Previous attempts to employ various kinds of filters in such heated solid state gas sensor devices have been unsuccessful because such filters have been fouled by water vapor present in the ambient atmosphere and negatively affected by the high temperatures caused by the heater component of the device.
Accordingly, there is a need for an improved gas detection system which permits only selected low molecular weight gases to reach a solid state semiconductor sensor, and prevents nonselected, contaminant gases from reaching the sensor.
U.S. Pat. No. 5,296,196 discloses a device for detecting large molecular weight hydrocarbons. The device includes a semiconductor sensor having a zeolite inorganic molecular sieve filter. The pores of the zeolite are doped with a catalyst metal. Small molecular weight hydrocarbons are caught in the pores and oxidized by the metal into water and carbon dioxide, so that only large molecular weight hydrocarbons pass through the filter to the sensor.
U.S. Pat. No. 5,143,696 discloses a device for detecting small molecular weight gases. The device includes an electrochemical sensor having a capacitor coated with a layer of a zeolite inorganic molecular sieve serving as a dielectric. The zeolite is doped with metals for oxidizing or adsorbing of molecules which diffuse into the zeolite pores.


A method for processing registers in an out-of-order processor. A predicate in an instruction is predicted. An architecturally correct value is then computed using a read-modify-write operation. The predicted value is compared to the architecturally correct value. The instruction with an incorrectly-predicted predicate is flushed from the pipeline if the predicted value and the architecturally correct value are different.

Microprocessors often use instruction pipelining to increase instruction throughput. An instruction pipeline processes several instructions through different stages of instruction execution concurrently, using an assembly line-type approach. Furthermore, these instructions may be executed in a dynamically scheduled (e.g., out-of-order) processor.
In the Itanium Architecture, an instruction may include a "qualifying predicate". The value of the qualifying predicate determines whether the instruction is executed or not. Itanium Architecture uses 64 predicate registers.
The performance of out-of-order computers using predicate registers, may be degraded by dependencies. A dependency exists between two instructions if the execution of one depends upon the results of executing the other. Thus, each instruction has the potential to stall later instructions that depend on it. Therefore, in some applications, predicates may be predicted in advance to remove the dependencies. However, verifying predicate prediction and maintaining the architecturally correct predicate registers are often cumbersome and tedious process because each predicate register must be verified and maintained individually.

Out-of-order processing with predicate prediction and validation with correct RMW partial write new predicate register values


A method for searching for devices for Bluetooth communication in a wireless terminal, by which Bluetooth communication can be easily carried out through various search options. The method includes displaying search options if a search is selected for a Bluetooth communication, displaying search keywords corresponding to a search option if the corresponding search option is selected from the search options, and attempting a Bluetooth communication with a device corresponding to the corresponding search keyword if the corresponding search keyword is selected from the displayed search keywords.

1. Field of the Invention
The present invention generally relates to a method for searching for devices for Bluetooth communication in a wireless terminal, and more particularly to a method for searching for devices for Bluetooth® (hereinafter "Bluetooth") communication in a wireless terminal which can easily carry out Bluetooth communication through various search options.
2. Description of the Related Art
Conventional processes of searching for devices for Bluetooth communication in a device with a Bluetooth function may be classified into a Generic Access Profile (GAP) process and a Service Discovery Protocol (SDP) process.
The GAP includes an inquiry, a name discovery, and a device discovery, through which it is possible to gain information with respect to a device address, a device name, and a class of device.
The SDP, among the processes of searching for Bluetooth, provides information in relation to an available service, which is provided by a device capable of carrying out Bluetooth communication.
The SDP generally includes SDP clients and an SDP server. All devices having a Bluetooth function must have a function as the SDP client or server, or both functions as the SDP client and server. Since the SDP has a client and server structure, most SDP instructions have request and response structures. When the SDP client requests the service discovery, the SDP server responds to the request.
The SDP server has a database including information with respect to all services which are provided by the device to which the SDP server belongs and which has a Bluetooth function. Therefore, when the SDP client requests the SDP server do something, the SDP server can search the database and respond to the request. At this time, the SDP server informs the SDP client of the property of services provided by the device having the Bluetooth function, using assigned numbers which are designated by a Bluetooth Special Interest Group (Bluetooth SIG) and called a "Universally Unique Identifier (UUID)". The SDP server can obtain the service information supported by the device to carry out the Bluetooth communication, through the above mentioned SDP process.
The SDP server carries out the Bluetooth communication with a corresponding device using a Bluetooth address and a service ID which the SDP server gains through the above mentioned searching process, and is connected to the corresponding service of the device carrying out the Bluetooth communication with the SDP server. The SDP server generates a link-key as soon as it is connected to the corresponding service, and then stores the link-key. The link-key stored in the database is used when the SDP server is connected to the corresponding device again, so that the SDP server avoids performing the above-mentioned searching process again.
However, the conventional wireless terminal merely stores the link-key in the database, and has no function to search for desired information from a database corresponding with each search option. For example, in order to connect a stereo headset to the wireless terminal, the wireless terminal merely seeks a device corresponding to the stereo headset among the devices stored in the database and connects the device to the wireless terminal. Further, in the wireless terminal, since the SDP process is improperly performed and all service information needed to operate the device is not stored, there exists an inconvenience in that the search is carried out from the beginning again in order to connect the wireless terminal to another service of the same device.

Method for searching for devices for Bluetooth communication in wireless terminal


Several shade assembly embodiments are disclosed which allow the shade assembly to be mounted in a vehicle interior while accommodating varying interior widths. In one embodiment, spring-biased latches engage a depression in an outer lateral surface of the roller assembly. In a related embodiment, a release button is included on the roller assembly. In an alternative embodiment, a U-shaped spring is biased axially outwardly of the roller assembly to engage a mounting surface on an opposed wall of the vehicle interior. In another embodiment, an end member comprises attachment structure having a lower member biased radially away from a longitudinal axis of an upper member. A bracket receives the end member and has an opening that is smaller than the expanded distance of the end member when the lower member is biased away from the upper member. The upper and lower members can be biased together such that the end member may be moved into the bracket. The upper and lower members are then released, and the end member secures itself within the bracket. In a final embodiment, a housing surrounds the roller assembly and has a hook which is to be moved into an opening in a rear panel of the vehicle. The assembly is thus not subjected to problems caused by variations of width in the vehicle interior since the roller member is mounted on a hook that will be secured to a wall opposed to the surface where the cover will be attached. The cover is pulled outwardly away from the hook, and thus the cover itself will accommodate any variation in distance.

The present invention relates to mounting structure for shade assemblies to cover a vehicle luggage compartment.
Shade assemblies have covers that extend by unwinding from a roller to cover valuables located in the vehicle compartment. The cover may also be retracted by winding the cover onto the roller.
Known shade assemblies have been mounted by securing ends of the roller or shade assembly to fixed mounting brackets on interior walls of the vehicle. One problem with known shade assemblies is that the width of the vehicle interior varies due to production variations from vehicle to vehicle. Thus, the lateral distance between the fixed mounting brackets also varies. The known art has made attempts at trying to address this problem.
In one prior example, spring-biased members are disposed at opposed ends of the roller in a shade assembly. The end members are urged into contact with a recess in a fixed mounting bracket.
In another prior example, a shade assembly includes fixed end members disposed at opposed ends of the shade assembly. The end members are inserted into a mounting hole of a fixed mounting bracket. A small plate is disposed in the mounting hole and a spring biases the plate toward the end members.
The spring biased mounting of the known shade assemblies have not been completely satisfactory.

Shade assembly mount for vehicle compartment


The method includes fabricating a plurality of elongated high permeability flux carrying members, and preparing n wire bundles each having a predetermined length. The n wire bundles are wound to provide a distributed winding configuration having a plurality of elongated open spaces. The plurality of flux carrying members are inserted into the plurality of open spaces to provide a winding/flux carrying member assembly. A bonding material is provided around the winding/flux carrying member assembly to provide a rigid structure.

Electromagnetic transducers are known for use both in transforming electrical power into mechanical power and transforming mechanical power into electrical power. In both cases, power producing capability results due to relative movement between fields, as is well known, for example, in the application of this phenomenon to motors, alternators and generators.
While it is well known that motor, alternator and generator devices can be made that are quite light in weight, and while at least some known lightweight devices have been capable of operation at high speeds, such devices have not been capable of operation at high speeds to produce high power. For example, high power density devices of 0.6 horsepower per pound of weight are known for intermittent operation, but such devices are incapable of continuous operation at high power densities in excess of 1.0 horsepower per pound.
Known electromagnetic transducer devices have also not been capable of simultaneous high speed and high torque operation and/or have not provided adequate efficiency in operation. In addition, prior shell construction devices have not used both dispersed conductors and dispersed phase flux carrying means in the armature and have, therefore, also been limited to low speed, which, even at high torque, leads to low power density.
It is also well known that an electromagnetic transducer can include a stator and rotor arrangement, and that such an arrangement can include positioning magnetic elements on the rotor (see, for example, U.S. Pat. Nos. 3,663,850, 3,858,071, and 4,451,749), as well as on the stator (see, for example, U.S. Pat. Nos. 3,102,964, 3,312,846, and 3,602,749, 3,729,642 and 4,114,057). It has also been heretofore suggested that a double set of polar pieces could be utilized (see, for example, U.S. Pat. No. 4,517,484).
In addition, a shell type rotor has been heretofore suggested (see, for example, U.S. Pat. Nos. 295,368, 3,845,338 and 4,398,167), and a double shell rotor arrangement has also been suggested (see, for example, U.S. Pat. No. 3,134,037).
It has also been heretofore suggested that a bundle of wires can be utilized in place of a single conductor in the armature assembly of a motor (see, for example, U.S. Pat. Nos. 497,001, 1,227,185, 3,014,139, 3,128,402, 3,538,364 and 4,321,494, as well as British Patent No. 9,557) with such wires being stated to be for high voltage and high current usage and/or to reduce current flow loss, the so-called skin effect, and heating due to eddy currents, and with such wires being utilized in conjunction with solid and/or laminated cores (see, for example, U.S. Pat. Nos. 3,014,139, 3,128,402, and British Patent No. 9,557).
It has also been heretofore suggested that an electromagnetic transducer could have a power to weight ratio of up to about one horsepower to one pound (see, for example, U.S. Pat. No. 3,275,863). In addition, cooling of a motor, to increase power handling capability, using a gas, liquid, or a mixture of a gas and liquid, is well known (see, for example, U.S. Pat. No. 4,128,364).
While various arrangements for electromagnetic transducers have therefore been heretofore suggested and/or utilized, such transducers have not been found to be completely successful for at least some uses, including providing a lightweight transducer that is capable of providing high power.
In particular, the prior art does not teach the necessity to disperse the conductors to enable high speed operation, due, at least in part, to a widely taught theory that the magnetic field is very low in the conductors. With conductors built according to conventional teachings, however, it has been found that torque, at constant current, decreases with increasing speed, which result is contrary to the conventional expectation that torque would remain high as speed increases (which is the result achieved by this invention).
Prior art transducers are typically constructed such that the flux carrying elements are built up from laminated stacks of silicon steel, with heavy wire being wound directly in the wide, open slots between the laminated iron teeth. The tooth tips often cause wire breakage.
Conventional brushless DC motors up to six inches in diameter generally have a practical maximum of 36 laminated iron teeth. For a conventional three-phase motor, the number of slots per pole is three. Such motors have wedge or V-shaped slots (see FIG. 31) formed by the laminated teeth, with the result that the copper wires in the winding cannot be uniformly arranged such that the copper in some conductors (turns) cannot be located close to the iron teeth. For example, in a conventional six-inch diameter motor, the distance between the conductor farthest from the tooth (but inside the slot) is 0.158 inch. The resulting electromotive force (emf) induced in the turns of the coils is not at all uniform. This nonuniformity of emf requires circulating currents to be controlled by twisting the wires within the coil, resulting in less wire in the slot and more in the end turns and difficult manufacture.
Conventional motors also generally require a large number of turns per slot. This causes an increased reactive effect and large opposing magnetic fields. This results in greater degradation of power output.

Method of making an electromagnetic transducer


A method of use and apparatus for a quick connect coupling in a fluid system as disclosed herein. The quick connect coupling includes a female coupling assembly and a male coupling assembly. The female coupling assembly includes a female cone housing nestable with a female cone. At least one female flow hole is formed in each of the female cone housing and female cone. The male coupling assembly has a male cone housing nestable with a male cone. At least one male flow hole is formed in each of the male cone housing, and the male cone. The at least one female flow hole rotatably misaligns to seal in a manner that fluid is contained from leaking past the female coupling assembly. The at least one male flow hole rotatably misaligns to seal in a manner that fluid is contained from leaking past the male coupling assembly. The male coupling assembly is removably rotatably insertable into the female cone. The female coupling assembly and the male coupling assembly rotatably fluidly couple to create a fluid flow path through the quick connect coupling. The female coupling assembly and the male coupling assembly rotatably fluidly uncouple, thereby sealing the fluid flow path through the quick connect coupling. The male coupling assembly and the female coupling assembly are removably uncoupleable.

Quick-connect coupling devices for joining two hoses together in a sealable manner are well known in the art. They are of relatively complex construction and include finely machined surfaces which are subject to wear, and generally comprise two pieces. A socket member is one piece, and a plug member is the other piece. The plug member is adapted to fit into the socket member in a male to female fashion. These members are formed of materials that wear after repeated use and are constructed in designs that inherently wear the sealing surfaces. The wear usually manifests in increased tolerances between sealing surfaces of the pressure boundary of the coupling. Ultimately, the coupling pressure boundary formed by the sealing surfaces fails resulting in system leakage.
In many fluid applications, leakage of the system fluid is unacceptable. In the refrigeration industry smaller refrigeration systems require lower leak rates. This is not only for a cleaner environment, but because the smaller system has less capacity to compensate for system refrigerant losses. Consequently, the smaller refrigeration systems that have a low refrigerant volume require system equipment with low leak rates. The couplings in these systems must also have fewer failure mechanisms that allow leakage from the fluid system. Accordingly, there exists a need for a high reliability self-sealing refrigerant coupling.
A method of use and apparatus for a quick connect coupling in a fluid system as disclosed herein. The quick connect coupling includes a female coupling assembly and a male coupling assembly. The female coupling assembly includes a female cone housing nestable with a female cone. At least one female flow hole is formed in each of the female cone housing and female cone. The male coupling assembly has a male cone housing nestable with a male cone. At least one male flow hole is formed in each of the male cone housing, and the male cone. The at least one female flow hole rotatably misaligns to seal in a manner that fluid is contained from leaking past the female coupling assembly. The at least one male flow hole rotatably misaligns to seal in a manner that fluid is contained from leaking past the male coupling assembly. The male coupling assembly is removably rotatably insertable into the female cone. The female coupling assembly and the male coupling assembly rotatably fluidly couple to create a fluid flow path through the quick connect coupling. The female coupling assembly and the male coupling assembly rotatably fluidly uncouple, thereby sealing the fluid flow path through the quick connect coupling. The male coupling assembly and the female coupling assembly are removably uncoupleable.

System and method of use for a refrigerant quick-connect coupling

International Business Machines Corporation


A video decoder includes a mode of operation for reverse playback that includes dividing a sequence of coded video data into groups of pictures (GOPs) and further subdividing the groups of pictures into a plurality of spans. Each span is processed in reverse coding order by decoding the first key frame and any reference frames that precede the currently processed span in coding order, selecting a plurality of frames from the currently processed span for decode and display and further selecting for decode but not display any reference frames from the currently processed span that were omitted by the first selection. The method accommodates control parameters that define the number of spans selected from each GOP and the number of frames selected from each span for decoded and display.

Video decoder systems are well known components of consumer electronic devices, such as personal computers, media players, video games and the like. They process a coded video bit stream, which is a compressed representation of a source video sequence, to generate a replica of the video sequence for local display. The consumer electronic devices render the video sequence according to a default display order but typically also support various enhanced playback modes, commonly fast forward and reverse playback. The present invention is directed to control methods for reverse playback.
Video coding typically exploits temporal redundancies among frames in a video sequence and generates coded video data that contains prediction references between frames. Often prediction references create multi-frame prediction chains, which must be traversed entirely during decode to regenerate the source video sequence. For this reason, a decoder cannot select and decode a desired video frame on a purely random access basis. Nor can a decoder work backwards through the coded video data, when operating in a reverse playback mode, decoding and rendering frames as it goes.
Prior attempts to implement reverse playback in video decoders generally operate in one of several ways. In an extremely simple case, a video decoder may decode only those frames which have no coding dependencies upon other frames (e.g., I frames) and skip all other frames. The acceptability of this approach depends on how frequently the I frames appear in coded video data. If every frame is coded as an I frame, reverse playback will look perfect. If the I frames occur infrequently in the coded video data, reverse playback cannot be presented as smooth video; reverse playback would be more akin to a slideshow. Because I frames often are extremely sparse in coded video data to optimize video compression performance (less than one frame in every hundred frames), there is a need for reverse playback algorithms that display more than just the I frames.
Other solutions to achieve reverse playback attempt to decode each coded video frame in reverse decoding order, which includes for each frame of interest decoding all frames that serve as prediction references. This approach is computationally expensive and can require reference frames to be decoded multiple times as the video decoder works backward through the coded video sequence in display order. Often, video decoders cannot complete full decode operation in the time available under the display's display rate, which may cause the video decoders to drop frames from decode and degrade video quality. Still other solutions attempt to decode an entire prediction chain in natural coding order and buffer the decoded video data for display in a reverse playback mode. This approach also is expensive, requiring large memory spaces to be allocated for this purpose. If adequate memory space is unavailable for reverse playback, frames may have to be dropped and video quality may be degraded.
Accordingly, there is a need in the art for a reverse playback control method for a video decoder that conserves resources and retains adequate video quality on playback.

Control of video decoder for reverse playback operation


A frequency extension circuit, consistent with certain embodiments of the present invention has a first delay line (108) having a plurality of taps. The delay line receives a reference clock at an input with a clock rate of FREF. A second delay line (104, 150) also receives the reference clock at an input. A logic circuit (130, 134, . . . , 138, 140) combines signals from the delay line taps of the first delay line (108) with signals from the delay line taps of the second and/or first delay line (104, 150, 108) to produce a collection of clock pulses having a combined clock rate of FREF*2N. At least one of the delay lines can be locked to the reference clock using a delay locked loop. The clock pulses can be logically combined with a seed register (204) contents to produce a recursive sequence or with data for convolutional encoding, or with pilot data for correlation in a CDMA transceiver.

The air interface specification for many CDMA transceivers can be quite complex. Most currently available Digital Signal Processors (DSP) either consume too much power, or they do not have enough correlation capacity for chip level processing. This is especially important for battery powered devices, since the power consumed directly relates to the battery life and frequency of charging or battery replacement. As the requirements for more and more processing power increase, this problem is compounded. This is especially true for high frequencies of operation dictated by high data rates, such as those specified for the third generation (3G) and beyond for CDMA, where these issues present significant obstacles to designers.

Delay line based multiple frequency generator circuits for CDMA processing


A process for increasing the diastereoisomeric ratio (B/A+B), wherein B is the more apolar and A is the more polar of two diastereoisomers, of a mixture of diastereoisomers of a compound of formula

The present invention relates to cefpodoxim proxeril of formula
e.g. described in The Merck Index, Twelth Edition, Item 1991, and more particularly to a process for the adjustment, e.g. change, of the diastereoisomeric ratio of the two existing diastereoisomers being with respect to the carbon atom attached to the oxygen of the ester group in the carboxyl ester group in position 4 of the ring system (marked with a star (*) in formula II). A diastereoisomeric ratio (B/A+B) of cefpodoxime proxetil currently on the market may be around 0.53. B is the more apolar of the two diastereoisomers. Because of different bioavailability of these individual diastereoisomers a commercial form for oral administration of cefpodoxim proxetil has to be within a defined ratio (B/A+B); otherwise such a form might not be bioequivalent. A diastereoisomeric ratio (B/A+B) of 0.5 to 0.6 has been found to be bioequivalent with a commercial form. Determination of the diastereoisomeric content of the diastereoisomers A and B in cefpodoxime proxetil may be carried out by HPLC, e.g. as described in Pharmacopeial Forum, Vol. 23, No. 4, p. 4388 ff (1997), the content of which is incorporated herein by reference, from which a diastereoisomeric ratio (B/A+B) and (A/A+B) may be calculated.
One process in the production of cefpodoxime proxetil may be carried out via acylation of 7-amino-3-methoxy-methyl-3-cephem-4-carboxylic acid-1-(isopropoxycarbonyloxy)ethylester of formula
with activated Z-2-(methoxyimino)-2-(2-formylaminothiazol-4-yl)-acetic acid to obtain N-formylcefpodoxime proxetil of formula
It was found that a mixture of diastereoisomers of a compound of formula I may be obtained in a diastereoisomeric ratio (B/A+B) of 0.48 to below 0.50. The reaction for splitting off the formyl group in a compound of formula I obtained to obtain cefpodoxime proxetil of formula II may have no significant influence on the diastereoisomeric ratio (B/A+B) and consequently (B/A+B) in cefpodoxime proxetil obtained may be outside of 0.5 to 0.6. Surprisingly a simple process has now be found wherein an appropriate diastereoisomeric ratio of the diastereoisomers of a compound of formula I may be obtained which may, result in cefpodoxime proxetil by splitting off the formyl group in a diastereoisomeric ratio which is 0.5 to 0.6.
In one aspect the present invention provides a process for the adjustment, e.g. change, of the diastereoisomeric ratio (B/A+B), wherein B is the more apolar of the two diastereoisomers, of a mixture of diastereoisomers of a compound of formula I, e.g. adjusting a diastereoisomeric ratio (B/A+B) to 0.5 to 0.6; the diastereoisomers being with respect with the carbon atom marked with a star in formula I, comprising treating a mixture of diastereoisomers of a compound of formula I, e.g. in an additive, e.g. a compound selected from an organic amide, an urea, an imidazolidinone or a pyrimidinone, e.g. a 10 to 50% (w/w) solution of a mixture of diastereoisomers of a compound of formula I in an additive; with alcohol, e.g. selecting the alcohol from (C1-6)alcohols; and water, e.g. treating a mixture of diastereoisomers of a compound of formula I with 3 ml to 10 ml alcohol and 10 ml to 30 ml water per gram of a compound of formula I.
A process according to the present invention may be carried out as follows:
A compound of formula I may be produced, e.g. in conventional manner and e.g. as follows: The carboxylic acid group in position 4 of the ring system of 7-amino-3-methoxymethyl-3-cephem-4-carboxylic acid (AMCA) which is a known compound and obtainable e.g. in conventional manner, may be esterified to obtain a compound of formula III. This may be effected e.g. in conventional manner, e.g. by reacting AMCA with a compound of formula
Xxe2x80x94CHxe2x80x94(CH3)xe2x80x94Oxe2x80x94COxe2x80x94Oxe2x80x94CH(CH3)2
wherein X denotes a leaving group, e.g. a conventional leaving group, such as a halogenide, e.g. an iodide; e.g. in the presence of a solvent. Esterification may be effected e.g. in a conventional solvent, e.g. an organic solvent such as ketones, e.g. acetone, e.g. in the presence of a hydrocarbon, e.g. toluene; and e.g. in the presence of a base; e.g. an amidine, such as 1,5-diazabicyclo(4,3,0)non-5-ene (DBN) and 1,8-diazabicyclo(5,4,0)undec-7-ene (DBU); or a guanidine, e.g. a linear guanidine, such as tetramethylguanidine, pentamethylguanidine, tetraethylguanidine, tetramethylethylguanidine and tetramethylbenzylguanidine or a cyclic or bicyclic guanidine, e.g. 1,5,7-triazabicyclo-(4,4,0)-dec-5-ene, and 7-methyl, 7-ethyl, 7-benzyl and 7-phenyl derivatives thereof. A compound of formula III obtained may be isolated, if desired, e.g. in conventional manner.
The nitrogen atom in position 7 of the ring structure of a compound of formula III, e.g. obtained as described above, e.g. with or without isolation, preferably without isolation, may be acylated e.g. in conventional manner. This may be effected e.g. by reaction of a compound of formula III obtained in in the esterifcation reaction, with activated Z-(2-formamidothiazol-4-yl)-methoxyimino acetic acid, e.g. including an ester and an acid halogenide, such as Z-(2-formylaminothiazol-4-yl)-methoxyimino-acetic acid chloride, e.g. in the form of a salt, e.g. a hydrochloride, including activated Z-(2-formamidothiazol-4-yl)-methoxyimino acetic acid obtainable by a Vilsmeier reaction. Vilsmeier activated Z-(2-formamidothiazol-4-yl)-methoxyimino acetic acid may be produced e.g. in conventional manner, e.g. in situ in the reaction mixture e.g. by treating Z-(2-formamidothiazol-4-yl)-methoxyimino acetic acid with phosphoroxyhalogenide, e.g. chloride, e.g. under Vilsmeier reaction conditions.
Acylation may be carried out in an organic solvent, including e.g. carboxylic acid esters, e.g. acetates, such as ethyl acetate; halogenated hydrocarbons, e.g. aliphatic, such as methylene chloride; e.g. in the presence of an amide, e.g. N,N-dimethylformamide; e.g. in the presence of pH adjustment. pH adjustment may be effected e.g. by addition of a base, such as an inorganic base, e.g. a carbonate or bicarbonate, e.g. sodium and potassium, or e.g. of an, e.g. weakly, basic anionic exchange resin, to a pH of ca. 2.5 to 8.0. A compound of formula I obtained may be isolated, e.g. in conventional manner. A mixture of diastereoisomers of a compound of formula I may be obtained in a diastereoisomeric ratio (B/B+A) of 0.47 up to below 0.5.
For adjustment, e.g. change, of the diastereoisomeric ratio of a mixture of diastereoisomers of a compound of formula I, e.g. obtained as described above, e.g. with or without isolation, preferably without isolation, e.g. a reaction mixture from acylation, e.g. as described above, may be treated with alcohol and water, e.g. in the presence of an additive, e.g. a compound which is liquid under the reaction conditions and wherein a compound of formula I may be dissolved, e.g. a compound selected from an organic amide, e.g. an amide of formic acid or acetic acid, or a cyclic amide, e.g. pyrrolidone or N-methylpyrrolidone, or an urea, e.g. tetramethylurea, or an imidazolidinone, e.g.1,3-dimethyl-2-imidazolidinone (DMEU) or a pyrimidinone, e.g.1,3dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone (DMPU), or a mixture of individual additives, e.g. as described above, preferably an organic amide or an urea. An additive may be added to a reaction mixture obtained in the acylation step. From a reaction mixture obtained in the acylation step, e.g. containing an additive, e.g. added after acylation reaction to the reaction mixture, a solvent used in the acylation step which is different from an additive described above may be evaporated off, e.g. keeping the main part of an additive in the evaporation residue.
A reaction mixture obtained in the acylation step or an evaporation residue as referred to hereinafter, e.g. obtainable e.g. as described above may be a solution, an, e.g. 10 to 50% (w/w) solution, of a mixture of diastereoisomers of a compound of formula I in an additive, containing e.g. water, e.g. small amounts, e.g. originating from the acylation step, and e.g. containing amounts of organic solvent, e.g. other than an additive, e.g. organic solvent as used in the esterification and/or acylation step, e.g. from trace amounts up to 30% (w/w) in respect with a compound of formula I, e.g. depending whether, or in which extent, an evaporation step is used.
A reaction mixture obtained in the acylation step, or an evaporation residue obtained as described above, may be treated with water and alcohol, e.g. adding, e.g. dropwise or e.g. by allowing to flow
an evaporation residue or a reaction mixture obtained in the acylation step to, e.g. into, a mixture of alcohol/water, or
a mixture of alcohol/water to, e.g. into, an evaporation residue or a reaction mixture obtained in the acylation step, or
an evaporation residue or a reaction mixture obtained in the acylation step to, e.g. into, alcohol; or alcohol to, e.g. into, an evaporation residue or a reaction mixture obtained in the acylation step; and adding, e.g. dropwise, water to, e.g. into, the mixture obtained; or adding the mixture obtained to, e.g. into, water.
Appropriate alcohols include e.g. (C1-6)alcohols, preferably methanol and ethanol and mixtures of individual alcohols. An appropriate amount of alcohol includes preferably an amount of 3 to 10 ml, e.g. 5 to 6 ml of alcohol per gram of a compound of formula I. An appropriate amount of water includes an amount which is greater than 5 ml, e.g. 10 to 30 ml per gram of a compound of formula I.
A compound of formula I may precipitate, e.g. in amorphous, e.g. filterable form. The diastereoisomeric ratio (B/B+A) of a mixture of diastereoisomers of a compound of formula I obtained may be dependent on the alcohol/water ratio in the mixture and may increase with increasing amounts of alcohol in respect with water. An alcohol/water ratio of about 1:1 to 1:6, preferably; 1:1.5 to 1:5 may conveniently be used to obtain a mixture of diastereoisomers wherein the diastereoisomeric ratio (B/B+A) is at least 0.5 and more.
In another aspect the present invention provides a process for the production of a mixture of diastereoisomers of cefpodoxim proxetil of formula II in a diastereoisomeric ratio (B/A+B), wherein B is the more apolar of the two diastereoisomers, of 0.5 to 0.6, the diastereoisomers being with respect with the carbon atom marked with a star in formula I, comprising producing a mixture of diastereoisomers of a compound of formula I, e.g. in a diastereoisomeric ratio of below 0.5, by acylating a compound of formula III, e.g. a mixture of diastereoisomers of a compound of formula III, e.g. produced by esterifying 7-amino-3-methoxymethyl-3-cephem-4-carboxylic acid with a compound of formula
Xxe2x80x94CHxe2x80x94(CH3)xe2x80x94Oxe2x80x94COxe2x80x94Oxe2x80x94CH(CH3)2
wherein X denotes a leaving group;
with activated Z-(2-formamidothiazol4-yl)-methoxyimino acetic acid,
treating a mixture of diastereoisomers of a compound of formula I in an additive e.g. a compound selected from an organic amide, an urea, an imidazolidinone or a pyrimidinone, e.g. a 10 to 50% (w/w) solution of a mixture of diastereoisomers of a compound of formula I in an additive; with alcohol, e.g. selected from (C1-6)alcohols, and water, e.g. treating a mixture of diastereoisomers of a compound of formula I with 3 ml to 10 ml alcohol and 10 ml to 30 ml water per gram of a compound of formula I; and splitting off the formyl group from the amino group attached to the thiazolyl group.
In another aspect the present invention provides a process for the production of a mixture of diastereoisomers of cefpodoxim proxetil of formula II in a diastereoisomeric ratio (B/A+B), wherein B is the more apolar of the two diastereoisomers, of 0.5 to 0.6, the diastereoisomers being with respect with the carbon atom marked with a star in formula II, characerized by the following steps
i) esterifying 7-amino-3-methoxymethyl-3-cephem-4carboxylic acid with a compound of formula
Xxe2x80x94CHxe2x80x94(CH3)xe2x80x94Oxe2x80x94COxe2x80x94Oxe2x80x94CH(CH3)2
xe2x80x83wherein X denotes a leaving group in the presence of a solvent, e.g. and in the presence of a base;
ii) acylating the amine group in position 7 of the ring system of a compound of formula III obtained in step i) with activated Z-(2-formamidothiazol-4-yl)-methoxyimino acetic acid, e.g. a halogenide, e.g. in the presence of a base;
iii) adding a compound selected from an organic amide, an urea, an imidazolidinone or a pyrimidinone to a reaction mixture obtained in step ii) and evaporating off a solvent used in the acylation step, and
iv) treating the evaporation residue obtained in step iii) with alcohol and water.
In a further aspect the present invention provides a process for the isolation of 7-[2-(2-formylaminothiazol-4-yl)-2-(Z)-(methoxyimino)-acetamido]-3-methoxyimino-3-cephem-4-carboxylic acid-1-(isopropoxy-carbonyloxy)-ethylester (as a diastercoisoineric mixture) of formula I; e.g. after the reaction of the compound of formula III with activated derivative of Z-2-(methoxyimino)-2-(2-formylaminothiazol-4-yl)-acetic acid in a solvent, characterised in that to the solution of the compound of formula I is added an organic amide, a urea, 1,3-dimethyl-2-imidazolidinone (DMEU) or 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone (DMPU), the solvent is subsequently removed by evaporation and the residue of evaporation is mixed with water/alcohol.
A process according to the present invention is useful for the production of cefpodoxime proxetil in a diastereoisomeric ratio (B/A+B), wherein B is the more apolar of the two diastereoisomers, of 0.5 to 0.6. A diastereoisomeric ratio (B/A+B) of 0.5 to 0.6 of cefpodoxime proxetil, e.g. in a pharmaceutical composition, is bioequivalent to cefpodoxime proxetil, e.g. in a pharmaceutical composition, currently on the market. Cefpodoxime proxetil produced according to the present invention may thus be used in the same dosages to and in the same indications as cefpodoxime proxetil currently on the market.
In the following examples, which illustrates the invention more fully, but should in no way limit its scope, all temperatures are given in degrees Celsius.
The following abbreviations are used:
DBU 1,8-diazabicyclo[5.4.0]undec-7-ene
DMF=N,N-dimethylformamide
TMG=tetramethylguanidine
AMCA=7-amino-3-methoxymethyl-3-cephem4-carboxylic acid
Determination of the diastereoisomeric content A and B in a compound of formula III, I and cefpodoxim proxetil may be carried out by HPLC, e.g. analogously, as described in Pharmacopeial Forum, Vol. 23, No. 4, p. 4388 ff (1997), from which a diastereoisomeric ratio (B/A+B) and (A/A+B) may be calculated.

Process for the preparation of cefpodoxime proxetil diastereoisomers

Abstract: the diastereoisomers being with respect to the carbon atom marked with a star in formula I, comprising treating a mixture of diastereoisomers of a compound of formula I with alcohol and water and isolating the precipitated compound of formula I in an increased diastereoisomeric ratio (B/A+B) of 0.5 to 0.6.


An automatic critique of resumes, cover-letters, and/or other types of documents is provided. The invention employs an input document, a processing device, and a set of rules specific to the document type. The processing device searches the document for specific patterns described by the rules, generates a list of potential errors in the document, generates advice on how to correct the errors and may produce various figures of merit for the document.

1. Field of the Invention
The invention pertains generally to processing of text documents, and in particular to methods of evaluating documents using criteria that is specific to the type of document being evaluated.
2. Description of the Related Art
The task of creating a resume that follows the conventions expected in the industry, while being technically correct, and including appropriate action words, and the like, is a time consuming and error prone process. Typically, the job seeker is not savvy as to the metrics used by the prospective employer in evaluating the formal aspects and general content of the resume. It will be appreciated that due to the large volume of resumes received, a number of companies will sort these resumes according to a number of subjective criteria, which are often not strictly related to the position being filled. The sorting of the resumes in this manner speeds the process of finding candidates that appear most suitable and serious about the position, and reduces the overhead inherent in the hiring process. Often resumes are first filtered by the human resources department, or other personnel, wherein only resumes ranking highly in the sorting process are viewed in more detail by human resources personnel or by the manager seeking to fill a particular position for which the resume has been sent. Job seekers would benefit from having their resumes checked and improved prior to submission.
Spelling and Grammar Checks
A number of tools exist for checking written documents, but these are generally provided to check generic document characteristics such as spelling and grammar, and allow for correction.
Spelling and grammar checking routines are incorporated in many word-processing programs to aid the user in generating a grammatically correct document. These tools are designed to check documents written in a specific language, but usually make no consideration for the specific type of document. Hence, they would apply the same set of rules to resumes, to cover letters, and to chocolate cake recipes. When applying spell-check or grammar-check to a resume, one would expect the detection of language errors, but will not expect to detect violations of even the most basic rules of effective resume and cover-letter writing.
Document-Specific Checks—Microsoft Power Point
One software tool that offers checks beyond grammar and spelling is Power Point, published by Microsoft from Redmond, Wash. The program takes advantage of the specific nature of the document—slide presentations—and applies several document-specific checks. One of the automatic checks verifies that slide titles use a user-selectable case (UPPER case, lower case, or Sentence case). Another check verifies that the body text of the presentation uses a user-selectable case (UPPER case, lower case, or Sentence case). Another check verifies that end-punctuation of paragraphs uses a user-selectable character such as a period. Another check requires that the total number of fonts used in the presentation does not exceed a user-specified number, such as 3. Another check verifies that text size of the slide title is larger or equal to a user-specified number of points such as 36. Another check verifies that the text size of the body text is larger or equal to a user-specified number of points such as 20. Another check verifies that the number of bullet points per slide does not exceed a user-specified number such as 6. Another check verifies that the number of lines per bullet point does not exceed a user-specified number such as 2.
Document Specific Checks—Performance Appraisal Writers
A program called Avantos Review Writer, published by Avantos Performance Systems of Emeryville, Calif. in 1994, was designed to assist managers in writing performance appraisals for their employees. The program provides various tools for writing the performance appraisal as well as checking it for conformance to a set of rules. These checks include "Legal Check," "Originality Check," and "Completeness Check." The "Legal Check" will flag, for example, the word "baby" as a potential reference to either age or behavior, which may not be appropriate in a performance appraisal document. The "Originality Check" will flag any case where the example text provided by the program was left unchanged in the final performance appraisal document. The "Completeness Check" looks for fields that were left blank and should have been filled to create a valid performance appraisal. Another performance appraisal tool, Performance Now, published by Knowledge Point of Petaluma, Calif. in 1994, also offered tools for writing performance appraisals and checking them for language that may reflect employment discrimination.
Resume Creation Tools
Several tools exist which are directed at the creation of winning resumes and cover letters, such as WinWay® Resume Deluxe, published by WinWay Corporation of Folsom Calif. Resume creation is a constantly evolving field, which seeks to maximize the efficiency with which resumes are created and the effectiveness of the completed resumes.
Specific Checks
One important area in resume creation involves the checking of the job history section, for example, verification of employment dates. One resume-writing program, "PFS:Resume and Job Search Pro" by The Learning Company of Cambridge, Mass., includes a "Verify Dates" feature. Provided that the user has entered their employment dates into the required fields, the "Verify Dates" feature checks "employment dates" conformance against a set of rules. For example, the "employment dates" field must conform to a standard date format such as "March 2000 to June 2001", "March 2000", "1990 to present." The program checks for format consistency of dates. Many dates formats are allowed, such as "1998", "march 1998" and "Jan. 31, 1998." The program checks that all dates within the same resume section use the same format. A string such as "very long ago" in the "employment date" field would be flagged as an error, with an acceptable year range including 1900-2100. A year such as "1790" could be considered as an error. The program also requires all dates to conform to the "reverse chronological order" rule, that is, the most recent job should be listed first. Any significant time gaps between jobs listed in the chronological section of the resume are flagged as errors. Date-range overlaps are flagged as a violation of the "reverse chronological order" rule. Upon detection of possible errors, this program reports the error to the user and may suggest a correction. While date checking is indeed a useful feature, this particular resume-writing program falls short in recognizing and reporting specific date cases. For example, if a resume contains two jobs with overlapping time periods, the program will report this as a violation of the "reverse chronological order" rule instead of pointing out that there is a date overlap, which could be a benign situation. Also, the program does not check the time-sequence ordering of schools listed in the education section. Further, and most importantly, this program falls short of protecting the user from many other potential pitfalls specific to the field of resume and letter writing, and cannot check resumes files unless those files contain the employment dates in certain designated fields.
Limitations of Existing Art
Application completeness is often a problem area in resume and letter creation and applicants may leave out important fields such as their full name, street address, phone number, alternate/cell-phone number, or e-mail address. When describing their work experience, applicants may forget to include employment dates, employment location, or job title. Applicants may describe a job just by job title and employment dates, without adding some helpful information about their specific tasks and accomplishments. When describing their education, applicants may neglect to include important information such as name of the school, degree obtained, or graduation date. Applicants may even omit whole sections of the resume such as Experience or Education. Such omissions could result in their resume being discarded.
Additionally, even if a required data item is entered, problems can arise with the applicant entering the wrong information, or inappropriate information within a given field. For example, an applicant who is using a template for writing their resume may leave template fields such as "<put your job title here>" or "<put number of experience years here>" intact. Also, an applicant could enter information about their age, religion, gender, sexual preference, where any of these items would be very troubling to a human resource professional who is trying to avoid potential discrimination complaints. When entering a web page address, applicant may accidentally enter an incorrect web address—one that leads nowhere, or even worse—one that leads to a page containing information that may reduce, rather than enhance their employment prospects. Likewise, applicants may enter an email address that is incorrect, thus making it very likely that any employer response will go unnoticed. Applicants may also make the common mistake of providing a phone number, street address or email address of a current employer; something their current or prospective employer may consider inappropriate. Even if the phone number is personal, the applicant may provide a phone number that is not monitored at all hours of the day, and neglect to make sure there is an answering machine connected to that number.
When describing their work experience, applicants may overlook problems with the dates associated with each job. Common problems include date overlap between two jobs, date gaps, where it appears that the applicant was unemployed for any period of time, or wrong ordering of the jobs, where the jobs are not ordered in reverse-chronological-order as is customary in resumes. Such date errors may cause a potential employer to discard an otherwise-acceptable resume and thus will reduce the chances of employment.
Furthermore, applicants may incorrectly or less effectively order the elements within the resume, or cover letter, and reduce their chances of being considered for a position. For example, an applicant who has just completed his/her PhD degree and whose entire employment history consists of temporary jobs at fast-food restaurants may inappropriately list these temporary jobs before describing the recently acquired and highly sought-after PhD degree. Less common but still possible errors include positioning of the Objective section anywhere but at the top of the resume, or positioning the References section anywhere but at the end of the resume.
When describing their Education, applicants may include information that is detrimental to their employment prospects, such as a GPA (Grade Point Average) that is lower than 3.0. Such GPA would better be left out of the resume. Also, applicants may overlook the opportunity to add value to their resume by describing various jobs they held in order to finance their tuition, or extra-curricular activities that add value to their degree or contribute to the community.
Within the References section, applicants may include names of references without properly preparing those references or even telling them that they are mentioned. Such practice may cause a person named as reference to provide inappropriate or even damaging information.
Applicants may also make formatting errors in their resume. For example, they may use page margins that are too small, too large, or unbalanced. They may also create a multi-page resume where the last page is almost empty, leaving the reader feeling that something is missing or the resume is out of balance. Applicants may create resumes that contain too many pages, where a shorter, more focused resume may produce better impression. Applicants may use fonts that are too large or too small for comfortable reading, or text colors that are too light to be reproduced well or difficult to scan by a computer scanner. They may use too many types of typefaces or too many text colors, distracting the reader from actual resume content. They may insert unusual characters such as "˜" or "\" by mistake, when they in fact intended to insert a valid character or a bullet. They may capitalize large sections of the resume to emphasize them, not realizing that readability is greatly impaired by this practice. The may use a non-standard typeface that only exists on their own system, but is not present on other systems. Hence certain characters that appear readable on the original system (e.g. a special type of bullet) may look completely different on another system. One particular case that comes to mind involves a resume that originally included a bullet character next to each phrase. However when our company received the resume via e-mail, it appeared to contain a question mark next to each accomplishment. Obviously this did not reflect well on the applicant.
A number of formatting, structure, and syntax faux pas can still occur on resumes that likewise limit the effectiveness of the resume and may thereby constrain probability of being seriously considered for a position. One area that is often missed is relating to the consistency conventions, whereas for example a particular structure may be correct when considered individually, but is inconsistent with other aspects of the resume, or cover letter (for example, inconsistency in capitalization, indentation, font size, color, end-punctuation of bullet items, etc.)
Applicants may use various stock phrases such as "Duties included" or "Responsible for" in their resume where a more proactive description of their roles would be much more attractive to a prospective employer. Applicants may also use words such as "I" or "me" in a resume where such wording is usually inappropriate. Other items that are best left out of the resume or cover letter include any discussion of salary, reason for leaving, physical attributes such as height, weight, date of birth, social security number, age, gender, marital status, spouse or children, religion, ethnic background and political affiliation.
Applicants may include photographs in their resume, something that is not recommended for any but few specific occupations such as modeling.
Most of the above issues apply equally to cover letters as well as to resumes. When creating a cover letter, applicants may forget to include a complete address for the employer they are targeting, or forget to include "Enclosure" line at the end indicating that a resume is enclosed.
When creating a resume, cover-letter, or similar employment-related document, the applicant wants to create the highest quality, most effective document based on their given qualifications. Unfortunately, to enhance effectiveness they are often left creating a number of tries and then visually attempting to determine how effective it might be.
It will be appreciated that resume programs address a need that goes beyond conventional word processing software, however, that current resume programs have significant limitations that may reduce the effectiveness of the final result.
Therefore, a need exists for an automated process to check resumes and cover letters for common errors that are not caught by generic spell-check and grammar-check processes. Such a tool will help users create enhanced resumes and cover-letters. The present invention satisfies those needs, as well as others, and overcomes the deficiencies of previously developed document processing systems and applications.


A microwave ablation system and method include an elongate microwave ablation probe. The probe has a radiating portion for performing microwave ablation. The probe includes a first electrode and a second electrode located along the probe body. A radiofrequency energy source is connected to the first and second electrodes. An impedance of tissue is measured using the first and second electrodes. The impedance is used to detect a change in tissue due to microwave ablation of the tissue. Therapy parameters for the microwave ablation procedure can be adjusted in response to the measured impedance. In some examples, one of the electrodes is proximal and one electrode is distal to the radiating portion.

Microwave ablation (MWA) is a minimally invasive energy modality for body treatments in many locations, including soft tissue lesions in the liver, kidney and lung. Microwave ablation probes use an antenna, such as a monopole or dipole antenna, to radiate microwave energy into tissue for heating. Unlike radiofrequency ablation, which depends on ion movement and friction for heating, microwave ablation energy causes water molecules to rotate due to the polarity of the molecules and generates heat due to hysteresis. It typically operates at industrial, scientific and medical (ISM) radio bands such as 500 MHz to 10 GHz, and more specifically can operate at 945 MHz or 2.45 GHz. Microwave ablation has advantages such as fast heating, allowing the probe to operate at high temperature to create larger lesions, and has been gaining market share over the past decade over radiofrequency ablation (RFA) for tissue ablation.

Microwave ablation probe with radiofrequency impedance sensing


A method and apparatus for recording and playing back computer graphics data, including cursor movement data, and audio data which requires no X-Window command extensions. During recording, the command data stream to a display controller is intercepted, time stamped at regular intervals, and sent to and stored in a first file in a mass storage device. Cursor movement and operation data also is intercepted, time stamped and stored in a second file. During recording, display state data is generated and recorded into a third file at specified intervals. For playback, the system operator is presented with a graphic user interface resembling the control panel of a video cassette recorder. The system operator can play back the recorded information starting from a designated instant by operating the "buttons" on the control panel. For playback, the third file is read and forwarded to the display controller. The first and second files are then merged utilizing the time stamps to ensure synchronization and forwarded in a stream to the display controller for playing back the recorded events.

X-Window is a standardized graphics language which is particularly adapted for use with UNIX-based computer operating systems. A comprehensive description of the X-Window protocol and language can be found in Adrianne Nye, Xlib Programming Manual, 3d edition, O'Reilly & Assoc., Inc. and Adrianne Nye (Editor), Xlib Reference Manual, 3d edition, O'Reilly & Assoc., Inc., both of which are incorporated herein by reference. X-Window is used in many graphics application environments. One such application is air traffic control display systems in which the flight of various aircraft in a designated air space is represented on computer display terminals which air traffic controllers can use to monitor air traffic.
In certain application environments, and particularly in the air traffic control environment, it would be advantageous to be able to record and playback the data which is displayed on the air traffic control terminal. It also would be advantageous to be able to record and playback the cursor movements and operations executed by an air traffic controller. The information is useful, for instance, in training air traffic controllers and for storing, retrieving and/or recreating air traffic incidents, such as aircraft collisions or near collisions and disappearance of aircraft.
Systems are available in the prior art for recording and playing back X-Window data. However, to my knowledge, these systems require customized extensions to the standard X-Window command protocol. The need for such extensions significantly limits the compatibility of the record and playback system with X-Window systems. Particularly, such record/playback systems cannot be used in conjunction with any X-Window system which does not also support the customized extensions needed for operation of the record/playback system.
Further, some of the record/playback systems utilize graphic user interfaces (GUIs) which require significant training and/or practice to master.
Accordingly, it is an object of the present invention to provide an improved method and apparatus for recording and playing back X-Window data.
It is another object of the present invention to provide an X-Window recording/playback system which requires no extensions to the standard X-Window protocol.
It is a further object of the present invention to provide an X-Window recording/playback system which is easy to learn and operate.
It is yet another object of the present invention to provide an X-Window recording/playback system which employs a graphic user interface which resembles a common consumer product, such as a VCR, so as to require virtually no training to operate.
It is yet a further object of the present invention to provide a method and apparatus for recording and playing back X-Window data with a high level of fidelity to the original recorded session.

Computer graphics data recording and playback system with a VCR-based graphic user interface


A toner composition comprised of hydrogenated resin particles and pigment particles.

This invention is generally directed to toner compositions, and more specifically, the present invention relates to developers comprised of toner compositions comprised of low melt resin particles. In one embodiment, the present invention relates to a toner composition comprised of hydrogenated resin particles, colorants, such as known pigment particles, and optional additives, such as charge control components. In another embodiment of the present invention, the toner composition can be hydrogenated to, for example, improve its blocking and release characteristics. More specifically, in one embodiment of the present invention there are provided developer compositions formulated by, for example, admixing low melting, about 220.degree. F. to about 300.degree. F., toner compositions hydrogenated with, for example, hydrogen or diimide, and carrier components. In another embodiment of the present invention, there are provided toner compositions with hydrogenated toner resins containing polymers prepared by bulk, solution, free radical, anionic, suspension, dispersion, or emulsion techniques, such as random or block copolymers (A-B).sub.n wherein n represents the number of repeating polymer segments and where A and B represent monomeric or oligomeric segments of, for example, styrene and butadiene, respectively, which components possess in embodiments of the present invention a desirable low fusion and low fusing energy; are easily jettable or processable into toner compositions; enable low temperature fusing; are optically clear; allow matte and gloss finishes; and with the toner resins illustrated herein there can in embodiments be fabricated brittle, rubbery, or other similar toner polymers with an optimized melt viscosity profile, and a lowering of the fusing temperature characteristics of the toner resin can be achieved. The hydrogenated toner polymers of the present invention can be processable by conventional toner means, that is these materials are extrudable, melt mixable and jettable. The toner compositions in embodiments of the present invention possess lower fusing temperatures, and therefore, lower fusing energies are required for fixing, thus enabling less power consumption during fusing, and permitting extended lifetimes for the fuser systems selected. Moreover, high gloss images may be obtained at lower fuser set temperatures. The toners of the present invention can be fused at temperatures (fuser roll set temperature) of between 220.degree. and 320.degree. F. in embodiments of the present invention as compared to a number of currently commercially available toners which fuse at temperatures of from about 300.degree. to about 370.degree. F. With further respect to the present invention, the ultra low melt resins have, for example, in embodiments thereof a glass transition temperature of from about 24.degree. to about 80.degree. C. and in embodiments employing cryogenic jetting conditions, glass transition temperatures of from about 0.degree. or less to about 24.degree. C. Known nonblocking characteristics, that is noncaking or retaining substantially all the properties of a free flowing powder at temperatures of, for example, about 120.degree. F. or less are obtained with the toner compositions of the present invention in embodiments thereof. Further, the treated toner compositions of the present invention can be selected for single component development in that, for example, the toners resist smearing, and do not form toner aggregates under the pressure stresses usually selected for such development systems. Also, toner compositions containing the hydrogenated resins illustrated herein can include wax components such as on the surface to improve the release characteristics of the toner. In embodiments of the present invention, the wax component can be situated on the surface of the toner by hydrogenation of unsaturated olefin groups on the surface of the toner particles. These toners (referred to as H-Shell toners) possess shells of hydrogenated resin which encapsulate softer lower melting cores. In other embodiments, the hydrogenated toners allow better compatibilization of wax release agents into the toner composition by extrusion process rather than by rubber roll mill methods usually required to assure sufficient mixing of the wax with the toner composition. In other embodiments, the hydrogenated toner compositions are more resistant to decomposition by light, and are oxidatively and more chemically stable than their unsaturated counterparts. The chemical inertness of the toner compositions allows for improved tribostability to diverse charge control agents which would ordinarily react with unsaturated olefins in the toner compositions. For example, certain aluminum containing charge control agents react with olefinic butadiene double bonds. Thus, the hydrogenated toner compositions of the instant invention and their images offer the advantages of enhanced light, chemical and thermal stability by the elimination of reactive butadiene double bonds by hydrogenation. Other advantages include improved compatibility with wax release agents using extrusion processing, and improved inertness of the toner compositions to charge control agents, improved release characteristics and compatibility with VITON.RTM. and silicone fuser rolls. Other advantages include improved crease test results with fused images indicative of better fixing of xerographic images to paper. Moreover, because the glass transition temperatures of hydrogenated styrene-butadiene copolymers are often increased after hydrogenation (or by addition of hydrogen across olefinic double bonds) toner blocking behavior is improved. Hydrogenation allows increased amounts of butadiene in copolymers with styrene while maintaining a high Tg of the toner composition (near 55.degree. C.). This translates into lower minimum fix temperatures due to increased soft nonstyrenic segments in the copolymers. The tribo-aging behavior is expected to be appreciably reduced due to the increased stability of the hydrogenated materials. Elimination of double bonds in the toners by hydrogenation is expected to improve fuser roll compatibility and improve release of molten toner images from the fuser roll to paper or transparency with improved image fastness or fix to paper. Increased copier reliability is anticipated.
Hydrogenation of toner resins or toner particles is accomplished by either heterogeneous (palladium on carbon) or the homogeneous Wilkinson or Crabtree catalysts. Diimide is also an effective reducing agent for the hydrogenation of olefinic bonds at atmospheric pressure in polar and apolar solvents. The advantage to diimide is that this reagent is expected to be an effective reagent for the hydrogenation of toner composition surfaces in alcohol or water and can be used to form hydrogenated polymer shells on toner surfaces. Improved blocking temperatures and release of toner images from fuser rolls result.
Toner and developer compositions are known, wherein there are selected as the toner resin styrene acrylates, styrene methacrylates, and certain styrene butadienes including those available as PLIOTONES.RTM.. Other resins have also been selected for incorporation into toner compositions inclusive of the polyesters as illustrated in U.S. Pat. No. 3,590,000. Moreover, it is known that single component magnetic toners can be formulated with styrene butadiene resins, particularly those resins available as PLIOLITE.RTM.. In addition, positively charged toner compositions containing various resins, inclusive of certain styrene butadienes and charge enhancing additives, are known. For example, there are described in U.S. Pat. No. 4,560,635, the disclosure of which is totally incorporated herein by reference, positively charged toner compositions with distearyl dimethyl ammonium methyl sulfate charge enhancing additives. The '635 patent also illustrates the utilization of suspension polymerized styrene butadienes for incorporation into toner compositions, reference for example working Example IX.
Numerous patents are in existence that illustrate toner compositions with various types of toner resins including, for example, U.S. Pat. Nos. 4,104,066, polycaprolactones; 3,547,822, polyesters; 4,049,447, polyesters; 4,007,293, polyvinyl pyridine-polyurethane; 3,967,962, polyhexamethylene sebaccate; 4,314,931, polymethyl methacrylates; Reissue 25,136, polystyrenes; and 4,469,770, styrene butadienes.
In U.S. Pat. No. 4,529,680, there are disclosed magnetic toners for pressure fixation containing methyl-1-pentene as the main component. More specifically, there are illustrated in this patent, reference column 2, beginning at line 66, magnetic toners with polymers containing essentially methyl-1-pentene as the main component, which polymer may be a homopolymer or copolymer with other alpha-olefin components. It is also indicated in column 3, beginning at around line 14, that the intrinsic viscosity of the polymer is of a specific range, and further that the melting point of the polymer is in a range of 150.degree. to 240.degree. C., and preferably 180.degree. to 230.degree. C. Other patents that may be of background interest include U.S. Pat. Nos. 3,720,617; 3,752,666; 3,788,994; 3,983,045; 4,051,077; 4,108,653; 4,258,116 and 4,558,108.
In addition, several patents illustrate toner resins including vinyl polymers, diolefins, and the like, reference for example U.S. Pat. No. 4,560,635. Moreover, there are illustrated in U.S. Pat. No. 4,469,770 toner and developer compositions wherein there are incorporated into the toner styrene butadiene resins prepared by emulsion polymerization processes.
Furthermore, a number of different carrier particles have been illustrated in the prior art, reference for example the U.S. Pat. No. 3,590,000 mentioned herein; and U.S. Pat. No. 4,233,387, the disclosures of which are totally incorporated herein by reference, wherein coated carrier components for developer mixtures, which are comprised of finely divided toner particles clinging to the surface of the carrier particles, are recited. In U.S. Pat. Nos. 4,937,166 and 4,935,326, the disclosures of which are totally incorporated herein by reference, there are illustrated, for example, carrier particles comprised of a core with a coating thereover comprised of a mixture of a first dry polymer component and a second dry polymer component not in close proximity to the first polymer in the triboelectric series. Other patents include U.S. Pat. No. 3,939,086, which teaches steel carrier beads with polyethylene coatings, see column 6; U.S. Pat. Nos. 3,533,835; 3,658,500; 3,798,167; 3,918,968; 3,922,382; 4,238,558; 4,310,611; 4,397,935 and 4,434,220.
Semicrystalline polyolefin resins or blends thereof are illustrated in U.S. Pat. No. 4,990,424 and U.S. Pat. No. 4,952,477, the disclosures of which are totally incorporated herein by reference. More specifically, in U.S. Pat. No. 4,952,477 there are disclosed toners with semicrystalline polyolefin polymer or polymers with a melting point of from about 50.degree. to about 100.degree. C., and preferably from about 60.degree. to about 80.degree. C. with the following formulas wherein x is a number of from about 250 to about 21,000; the number average molecular weight is from about 17,500 to about 1,500,000 as determined by GPC; and the M.sub.w /M.sub.n dispersity ratio is from about 2 to about 15.
I. Polypentenes-(C.sub.5 H.sub.10).sub.x PA0 II. Polytetradecenes-(C.sub.14 H.sub.28).sub.x PA0 III. Polypentadecenes-(C.sub.15 H.sub.30).sub.x PA0 IV. Polyhexadecenes-(C.sub.16 H.sub.32).sub.x PA0 V. Polyheptadecenes-(C.sub.17 H.sub.34).sub.x PA0 VI. Polyoctadecenes-(C.sub.18 H.sub.36).sub.x PA0 VII. Polynonadecenes-(C.sub.19 H.sub.38).sub.x ; and PA0 VIII. Polyeicosenes-(C.sub.20 H.sub.40).sub.x. PA0 I. poly(styrene.sub.m -butadiene.sub.n); PA0 II. poly(styrene.sub.m -isoprene.sub.n); PA0 III. poly(styrene.sub.m -butadiene.sub.n -butene.sub.o); PA0 IV. poly(styrene.sub.m -isoprene.sub.n -isopentene.sub.o); PA0 V. poly(styrene.sub.m -butadiene.sub.n)-CO.sub.2 H; PA0 VI. HO.sub.2 C-[poly(styrene.sub.m -butadiene.sub.n)]-CO.sub.2 H; PA0 VII. poly(styrene.sub.m -butadiene.sub.n -dihalobutene.sub.o); and PA0 VIII. poly(styrene.sub.m -isoprene.sub.n -dihaloisopentene.sub.o).
Examples of specific semicrystalline polyolefin polymers illustrated in this copending application include poly-1-pentene; poly-1-tetradecene; poly-1-pentadecene; poly-1-hexadecene; poly-1-heptadecene; poly-1-octadecene; poly-1-nonadecene; poly-1-eicosene; mixtures thereof; and the like. These materials are particularly suitable for making matte or low gloss black copies and prints.
In U.S. Pat. No. 5,278,016 the disclosure of which is totally incorporated herein by reference, there are illustrated toner compositions comprised of pigment particles and resin polymer particles, and wherein the toner is subjected to halogenation resulting in the formation of a toner shell. The aforementioned toner resin particles are preferably comprised of ultra low melt resin polymers, which in embodiments possess a glass transition temperature of from about 20.degree. to about 75.degree. C., and preferably from about 33.degree. to about 60.degree. C. as determined by DSC (differential scanning calorimetry), and wherein the toner melts at from about 220.degree. to about 300.degree. F. and preferably 250.degree. F. The halogenated, especially chlorinated, encapsulating polymer surfaces can possess glass transition temperature values between about 55.degree. and 110.degree. C., and preferably from about 100.degree. to about 110.degree. C. The high glass transition temperature surfaces, or shell impart, for example, robustness to the toners. The toner core comprised of resin and pigment has, for example, a glass transition temperature of from about 20.degree. to about 110.degree. C., preferably from about 25.degree. to about 60.degree., and more preferably about 40.degree. C., thus the toner is considered a low, or ultra low melting composition. The advantages of the hydrogenated resins over the halogenated toners of U.S. Pat. No. 5,278,016 are better control of the Tg of the shell coating that encapsulates the soft core. Partial catalytic hydrogenated ultra low melt polymers are disclosed on page 20 of the aforementioned copending application. Other advantages include improved release of toned images from the fuser roll, improved oxidative, light and chemical stability of toner compositions, chemical resistance to charge control agents for improved tribo stability, and improved lubricity of the toner compositions for better release from fuser rolls without sacrificing image fix.

Toner compositions with hydrogenated components


A method and apparatus for RF ripple correction in an antenna aperture are described. In one embodiment, the antenna comprises: an array of antenna elements having liquid crystal (LC); drive circuitry coupled to the array and having a plurality of drivers, each driver of the plurality of drivers coupled to an antenna element of the array and operable to apply a drive voltage to the antenna element; and radio-frequency (RF) ripple correction logic coupled to the drive circuitry to adjust drive voltages to compensate for ripple.

Display devices using liquid crystals (LC) typically use a drive method that inverts the polarity of the drive voltage applied across the LC at regular intervals. These intervals are typically called time frames or frames. This is done to prevent or minimize trapping of charges within the LC device that can result in a storage of a voltage within the LC device. These charges arise from numerous sources, mostly coming from contamination or a degradation of materials in the LC device. A persistent application of a given polarity separates the charges of contaminants (such as organic acids), and moves them to the boundaries of the LC device, where they may stick. By inverting the polarity of the applied voltage, the separation and transport of these charged species can be reduced. However, inverting the voltage symmetrically is difficult to do, and thus a "net DC offset" results.
A condition called "flicker" can also occur, which is caused when there is a sufficient difference between the absolute value of the voltage applied during a positive frame and that applied during a negative frame such that the optical properties of the LC in positive and negative frames are different and visible by a human eye. In a display, these may be seen or detected by a light sensing device. Over time, the asymmetry between the positive and negative frames that caused flicker results in storage charge. Stored charge within the device can create differences between the voltage that is intended to be applied to the LC, and the voltage that is actually applied. This can result in a reduction in the root mean squared (RMS) voltage applied to the elements. Another symptom of this problem, referred to herein as "image sticking", can occur, which is an influence of a previously applied image pattern upon the next image pattern.
Although regularly inverting the polarity of the applied voltage is effective to prevent charge trapping, this by itself is not sufficient to prevent problems like "flicker". If there is a sustained difference between the applied voltages in the positive polarity and the negative polarity, this can result in a "net DC offset" between the frames, whereby there is a net accumulation of charges at the boundaries of the LC device over time.
To prevent this in an LC-based device, it is desired that the DC offset between the absolute value of voltage applied to the LC device during the one interval of the drive polarity and the absolute value of the voltage applied during the next interval of opposite drive polarity be as close to zero as possible.
In LC displays, adjustment of the DC offset may be done by compensating the voltage value sent to each element for each polarity at every gray level. In a display, the amount of the compensation voltage at each polarity at chosen gray levels may be determined optically and is selected to null the flicker. That is, a voltage difference between the positive and negative polarity of frames results in an optical flicker, which can be observed by an optical sensor or array of sensors (camera) and nulled using a correction algorithm in an automated test setup. Then, those correction values can be stored and used for minimizing the offset.
A DC offset problem is described above for LC displays. The same phenomenon is observed in LC RF antenna since LC driving mechanism is the same as displays. The effect of this phenomenon is observed as RF ripple in the antenna performance which degrades the carrier to noise (C/N) ratio at the receiver. DC offset correction methods used in LC displays cannot be applied to the current state of the LC RF antenna because the antenna structure blocks the path for optical measurements of the LC response.