In forming a current channel estimate from a received signal y, the received signal y is decoded to form data s, a convolution matrix Ŝis formed from a first portion of the data s, a matrix F1 is formed from a second portion the data s such that the second portion of the data s includes data that is less recent that the data in the first portion of the data s, a matrix F2 is formed from a third portion the data s such that the third portion of the data s includes data that is more recent than the data in the first portion of the data s, a predicted channel estimate hpred is determined, and a conjugate gradient algorithm is performed to determine the current channel estimate. The conjugate gradient algorithm is based on the received signal y, the matrix Ŝ, the matrices F1 and F2, the predicted channel estimate hpred, and a previous channel estimate h1.

Since the adoption of the ATSC digital television (DTV) standard in 1996 in the United States, there has been an ongoing effort to improve the design of receivers built for the ATSC DTV signal. The primary obstacle that faces designers in designing receivers so that they achieve good reception is the presence of multipath interference in the channel.
The broadcast television channel is a relatively severe multipath environment due to a variety of conditions that are encountered in the channel and at the receiver. Channels are characterized by impulse responses which may be several hundreds of symbols long, so that strong interfering signals may arrive at the receiver both before and after the largest amplitude signal. In addition, the signal transmitted through the channel is subject to time varying channel conditions due to the movement of the transmitter and signal reflectors, airplane flutter, and, for indoor reception, people walking around the room. If mobile reception is desired, movement of the receiver must also be considered.
Moreover, the ATSC DTV signal uses trellis coded 8-level vestigial sideband (usually referred to as 8T-VSB or, more simply, as 8-VSB) as the modulation method. 8-VSB data symbols are real and have a signal pulse shape that is complex. Only the real part of the complex pulse shape is a Nyquist pulse. Therefore, even if there is no multipath, the imaginary part of the complex pulse shape contributes intersymbol interference (ISI) when the channel gain seen by the equalizer is not real.
Multipath and intersymbol interference adversely affect the ability of the receiver to correctly receive the symbols transmitted by the transmitter. Therefore, designers add equalizers to receivers in order to cancel the effects of multipath and intersymbol interference and thereby improve signal reception.
Because the channel is not known a priori at the receiver, the equalizer must be able to modify its response to match the channel conditions that it encounters and to adapt to changes in those channel conditions. To aid in the convergence of an adaptive equalizer to channel conditions, the field sync segment of the frame as defined in the ATSC standard may be used as a training sequence for the equalizer. But when equalization is done in the time domain, long equalizers (those having many taps) are required due to the long channel impulse responses that characterize the channel.
The original Grand Alliance receiver used an adaptive decision feedback equalizer (DFE) with 256 taps. This adaptive decision feedback equalizer was adapted to the channel using a standard least mean square (LMS) algorithm, and was trained with the field sync segment of the transmitted frame. The LMS algorithm converges quite slowly and, even with only 256 taps, does not always converge during a single training sequence. Because the field sync segment is transmitted relatively infrequently (about every 260,000 symbols), the total convergence time of this equalizer is quite long if the equalizer only adapts on training symbols prior to convergence.
Therefore, in order to adapt equalizers to follow channel variations that occur between training sequences, the addition of blind and decision directed methods to equalizers has been suggested. However, when implemented in a realistic system, these methods may require several data fields to achieve convergence, and convergence may not be achieved at all under difficult multipath conditions.
In any event, because multipath signals in the broadcast channel may arrive many symbols after the main signal, the decision feedback equalizer is invariably used in 8-VSB applications.
It has been argued that a blind decision feedback equalizer is required due to the rise in mean square error (MSE) between training sequences. However, adaptation of the trained equalizer in the simulation that supported this argument was frozen between training sequences. It is possible that a decision-directed equalizer with good tracking performance may be able to follow the channel variations tested.
Blind algorithms based on the Sato algorithm and on Godard's constant modulus algorithm (CMA) have been proposed. The error term in both of these algorithms uses a continuous blending of a decision-directed term with the blind term. This blending enables a smooth transition between the blind mode and the decision-directed mode. However, when implemented in a realistic system, these algorithms also may take several data fields to converge.
As mentioned previously, adaptive equalizers utilizing the least mean square (LMS) algorithm may converge slowly or not at all depending on the channel conditions. Convergence may be adversely affected if the input data auto-correlation matrix has a large eigenvalue spread. Also, if the decision feedback equalizer has not converged before the end of the training sequence, the shape of the objective function may change so that it includes local minima. These local minima may be caused by closed eye channel conditions and decision feedback equalizer error propagation.
The recursive least square (RLS) algorithm is well known to avoid these convergence problems. However, the recursive least square algorithm, in its basic form, requires the computationally intensive inversion of the input data auto-correlation matrix.
Lattice based forms of the recursive least square algorithm avoid the need for this matrix inversion. However, the lattice based forms of the recursive least square algorithm are not easily amenable to the advantage of initialization from an initial channel impulse response (CIR) estimate, even though such an initialization may be desirable.
Recent work in reduced rank filtering has connected the multi-stage nested Wiener filter (MSNWF) of Goldstein and Reed to the conjugate gradient algorithm (CG). It has been shown that the multi-stage nested Wiener filter solves the Wiener-Hopf equations in the Krylov subspace associated with the auto-correlation matrix and the cross-correlation vector. The multi-stage nested Wiener filter is then re-formulated using the Lanczos iteration. It has also been shown that the Lanczos-based multi-stage nested Wiener filter is equivalent to the conjugate gradient algorithm. Since the multi-stage nested Wiener filter often needs few dimensions to approach the performance of the full-rank Wiener filter, the conjugate gradient algorithm is a good candidate for an adaptive equalization algorithm with fast convergence.
A description of the conjugate gradient optimization algorithm and many of its mathematical properties may be found in "An Introduction to Optimization," by E. K. P. Chong and S. Zak, New York, N.Y., John Wiley & Sons, 1996. The algorithm described is applicable to the optimization of a fixed objective function. An excellent review of adaptive filtering with the conjugate gradient algorithm is found in "Analysis of conjugate gradient algorithms for adaptive filtering," by P. S. Chang and A. N. Willson, Jr., vol. 48, pp. 409-418, IEEE Transactions on Signal Processing, February 2000. The mathematical richness of the algorithm relationships leads to a variety of options in the implementation of the basic conjugate gradient algorithm for minimizing a quadratic objective function. These options can be carried over to the adaptive situation to provide a number of options for implementation of the algorithm. One characteristic of the algorithm which may also be exploited is that it works directly with the correlation matrices and vectors. This characteristic makes initialization based on an initial channel impulse response straightforward, assuming information is available for this purpose.
Like lattice based forms of the recursive least square algorithm, the conjugate gradient algorithm does not require the inversion of the input data auto-correlation matrix. Another characteristic of the conjugate gradient algorithm may be exploited by recognizing that the input data auto-correlation matrix is the product of two Toeplitz matrices.
It has been known internally by assignee to use these characteristics to substantially reduce the computation load in the conjugate gradient algorithm and to even eliminate the need to form the input auto-correlation matrix. Accordingly, the improved conjugate gradient algorithm disclosed in that application may be used to achieve satisfactory convergence times for equalizers.
It has also been known internally by assignee that the conjugate gradient algorithm can be used to estimate channels. The present invention reduces the computation complexity in performing the conjugate gradient algorithm with respect to channel estimators.

Efficient conjugate gradient based channel estimator


There is provided an electronic part incorporating connector in which an electronic part and a connecting part for connecting a lead of the electronic part to an electric wire are housed in a housing, wherein the housing is divided into a first housing for housing the electronic part and a second housing for housing the connecting part, and by connecting the first housing and the second housing to each other, the lead of the electronic part is connected to the connecting part.

A motor vehicle is mounted with a large number of actuators formed by a motor, a solenoid, and the like as electric equipment, and a control system for decentralized controlling the electric equipment independently by means of data communication has already been developed. In this system, a wiring harness as shown in FIG. 13 is used.
This wiring harness 10 is constructed by installing many connectors 14 on a combination wire 12, in which a plurality of electric insulated wires are collected, at desired intervals in the lengthwise direction, and is called a so-called bus wiring wire harness. Each of the connectors 14 in this wiring harness 10 is inserted in and connected to a connector 18 (equipment-side connector) on the electric equipment 16 side mounted at portions of a vehicle.
The connector 14 on the wiring harness 10 side incorporates a circuit board that identifies, among signals being transmitted through a combination wire 12, a signal (address) to the electric equipment to which the connector 14 is connected to carry out the control of the electric equipment (Unexamined Japanese Patent Publication No. 2004-172072). The connector of this type is also called a smart connector.
In recent years, as to the connector of this type, the incorporating of a communication control IC (integrated circuit) in place of the circuit board has been studied. However, since the communication control IC and other electronic parts are relatively expensive, if a trouble is found after the communication control IC has been incorporated, the expensive communication control IC may become wasteful. This decreases the yield of assembling process, resulting in an increase in cost.

Electronic part-incorporating connector and wiring harness with electronic part-incorporating connector


A voltage compensation system for an A.C. power line supplying one or more air conditioners, a telephone system or other telecommunication system, a battery charger, or some other utilization system that should have an input voltage within a given normal range. The voltage compensation system includes a transformer unit containing a transformer having at least two windings coupled electromagnetically by a transformer core; one of those windings preferably is in two segments that are connectable in series or in parallel. One winding is connected to an input terminal and to an output terminal. The other winding adds to the A.C. line voltage when the line voltage drops below a low voltage threshold and/or subtracts from the line voltage when the A.C. line voltage exceeds a high voltage threshold. If the A.C. line voltage is in the range required by the utilization system, the other transformer winding is effectively shorted out or otherwise disconnected. In automated versions, a line voltage sensor actuates a switching circuit to effect the desired compensation action. The voltage compensation system may handle under-voltage conditions, over-voltage conditions, or both. For chronic under-voltage or over-voltage conditions, direct winding connections may be employed instead of relays.

There are numerous different electrically-energized utilization systems that should have an A.C. input within a given normal voltage range. One example is an A.C. energized air conditioner; if the A.C. line energizing the air conditioner falls below a given threshold voltage level, whether permanently or for a substantial period of time, the air conditioner may overheat and may suffer permanent damage. Another example is a telephone or other telecommunication system or a battery charger that relies upon an A.C. input voltage in a given normal range. When the input voltage exceeds the upper limit of that range for any substantial period of time, the system may be severely damaged or even virtually destroyed. Other utilization systems may react adversely to inputs either above or below their normal input voltage range.
Compensation circuits have been proposed for both over-voltage and under-voltage A.C. power line conditions. For the most part, known voltage compensation devices have been relatively large and expensive. Indeed, the cost of an effective voltage compensation device may be comparable to the cost of the utilization apparatus that it protects.


Techniques to determine the position of a terminal under the coverage of a repeater in a wireless communication system. In an aspect, an identification code is transmitted for each repeater and used by the terminal (or a PDE) to unambiguously identify the repeater. The identification codes for the repeaters in the system can be implemented with PN sequences at defined offsets that are specifically reserved for repeater identification. In another aspect, the identification code for each repeater is transmitted using a spread-spectrum signal designed to have minimal impact on the performance of the system and to be recoverable by the terminal in similar manner as for a forward modulated signal. In this way, no additional hardware is required for the terminal to recover the identifier signal. In one specific design, the spread spectrum identifier signal is generated in accordance with and conforms to the IS-95 CDMA standard.

A common technique to locate a terminal is to determine the amount of time required for signals transmitted from multiple transmitters at known locations to reach the terminal. One system that provides signals from a plurality of transmitters at known locations is the well-known Global Positioning Satellite (GPS) system. Satellites in the GPS system are placed in precise orbits according to a GPS master plan. The position of the GPS satellites can be determined by different sets of information (commonly known as the "Almanac" and "Ephemeris") transmitted by the satellites themselves. Another system that provides signals from transmitters (e.g., base stations) at known earth-bound locations is a wireless (e.g., cellular telephone) communication system.
Many wireless communication systems employ repeaters to provide coverage for designated areas within the system or to extend the coverage of the system. For example, a repeater may be used to cover a particular area not covered by a base station due to fading conditions (i.e., a "hole" within the system). Repeaters may also be used to extend coverage into rural areas (e.g., along a freeway) that are outside the coverage area of the base stations. A repeater receives, conditions, and retransmits signals on both the forward link (i.e., the path from the base station to the mobile unit) and reverse link (i.e., the path from the mobile unit to the base station).
Various challenges are encountered in determining the location of a terminal in a system in which one or more repeaters are employed. Typically, a signal from a single base station is processed and retransmitted by a repeater at relatively high power and with a delay. The combination of the repeated signal's high power plus the isolation normally associated with the repeater's coverage area often prevent a terminal from receiving other signals from other base stations. Moreover, in many cases in which repeaters are used (e.g., inside buildings, tunnels, subways, and so on), the signals from GPS satellites have insufficient power levels to be received by the terminal. In this case, a limited number of signals (possibly only one signal, from the repeater) may be available for use to determine the terminal's location. Furthermore, the additional delays introduced by repeaters can distort the round trip delay/time of arrival (RTD/TOA) measurements as well as the TDOA measurements, which then results in inaccurate position estimate based on these measurements.
FIG. 1A is a diagram of a wireless communication system 100 that employs repeaters in accordance with the disclosed method and apparatus. System 100 may be designed to conform to one or more commonly known industry standards, such as IS-95, published by the Telecommunications Industry Association/Electronics Industry Association (TIA/EIA), and other such industry standards for systems such as W-CDMA, cdma2000, or a combination thereof. System 100 includes a number of base stations 104. Each base station serves a particular coverage area 102. While only three base stations 104a through 104c are shown in FIG. 1A for simplicity, it will be understood by those skilled in the art that there are typically many more such base stations in such a system. For the purpose of this disclosure, the base station and its coverage area are collectively referred to as a "cell".
One or more repeaters 114 may be employed by system 100 to provide coverage for regions that would not otherwise be covered by a base station (e.g., due to fading conditions, such as region 112a shown in FIG. 1A) or to extend the coverage of the system (such as regions 112b and 112c). For example, repeaters are commonly used to improve indoor coverage for a cellular system at relatively low costs. Each repeater 114 couples to a "serving" base station 104 via a wireless or wireline link (e.g., a coaxial or fiber optic cable) either directly or through another repeater. Any number of base stations within the system may be repeated, depending on the particular system design.
A number of terminals 106 are typically dispersed throughout the system (only one terminal is shown in FIG. 1A for simplicity). Each terminal 106 may communicate with one or more base stations on the forward and reverse links at any moment, depending on whether or not soft handoff is supported by the system and whether or not the terminal is actually in soft handoff. It will be understood by those skilled in the art that "soft handoff" refers to a condition in which a terminal is in communication with more than one base station at the same time.
A number of base stations 104 are typically coupled to one base station controller (BSC) 120. BSC 120 coordinates the communication for base stations 104. For the purpose of determining the position of terminal, base station controller 120 may also be coupled to a Position Determining Entity (PDE) 130. PDE 130 receives time measurements and/or identification codes from the terminals and provides control and other information related to position determination, as described in further detail below.
For position determination, a terminal may measure the arrival times of signal transmissions from a number of base stations. For a CDMA network, these arrival times can be determined from the phases of the pseudo-noise (PN) codes used by the base stations to spread their data prior to transmission to the terminals over the forward link. The PN phases detected by a terminal may then be reported to the PDE (e.g., via IS-801 signaling). The PDE then uses the reported PN phase measurements to determine pseudo-ranges, which are then used to determine the position of the terminal.
The position of a terminal may also be determined using a hybrid scheme whereby signal arrival times (i.e., times of arrival (TOA)) are measured for any combination of base stations 104 and Global Positioning System (GPS) satellites 124. The measurements derived from GPS satellites may be used as the primary measurements or to supplement the measurements derived from the base stations. The measurements from the GPS satellites are typically more accurate than those from the base stations. However, clear line-of-sight to the satellites is typically required to receive the GPS signals. Accordingly, the use of GPS satellites for position determination is generally limited to outdoor environment where obstructions are not present. GPS signals typically cannot be received indoors or in other environments where there are obstructions such as foliage or buildings. However, GPS has extensive coverage and four or more GPS satellites can potentially be received from virtually anywhere that there are no such obstructions.
In contrast, base stations are typically located in populated areas and their signals are able to penetrate some buildings and obstructions. Therefore, it is possible for base stations to be used in cities and potentially within buildings to determine the location of devices that can receive and/or transmit such signals. However, the measurements derived from base stations are typically less accurate than those from GPS satellites because multiple signals may be received at the terminal from a particular base station due to a phenomenon known as "multipath". Multipath refers to the situation in which signals are received via multiple transmission paths between the transmitter and receiver. Such multiple paths are generated by signals reflecting off various objects, such as buildings, mountains, etc. It should be noted that in the best case, the signal is also received on a direct path (straight line) from the transmitter to the receiver. However, this may not necessarily be true.
In the hybrid scheme, each base station and each GPS satellite represents a transmission source. To determine a two-dimensional estimate of the position of a terminal, the transmissions from three or more non-spatially aligned sources are received and processed. A fourth source may be used to provide altitude (a third dimension) and may also provide increased accuracy (i.e., reduced uncertainty in the measured arrival times). The signal arrival times can be determined for the transmission sources and used to compute pseudo-ranges, which can then be used (e.g., via a trilateration technique) to determine the position of the terminal. Position determination can be achieved by well know means, such as is described in the 3GPP 25.305, TIA/EIA/IS-801, and TIA/EIA/IS-817 standard documents.
In the example shown in FIG. 1A, terminal 106 may receive transmissions from GPS satellites 124, base stations 104, and/or repeater 114. Terminal 106 measures the signal arrival times of the transmissions from these transmitters and may report these measurements to PDE 130 via BSC 120. PDE 130 can then use the measurements to determine the position of terminal 106.
As noted above, repeaters may be used to provide coverage for regions not covered by the base stations, such as within buildings. Repeaters are more cost effective than base stations, and can be advantageously deployed where additional capacity is not required. However, a repeater is associated with additional delays due to circuitry within the repeater and cabling and/or additional transmission associated with the repeater. As an example, surface acoustic wave (SAW) filters, amplifiers, and other components within the repeater introduce additional delays that are comparable to, or may be even greater than, the transmission delays from the base station to the terminal. If the repeater delays are not taken into account, then the time measurements of the signals from repeaters cannot be reliably used to determine the position of a terminal.
FIG. 1B is a diagram illustrating the use of a repeater 114x to provide indoor coverage for a building 150. In the example shown, repeater 114x comprises a main unit (MU) 115 coupled to a number of remote units (RUs) 116. On the forward link, main unit 115 receives one or more signals from one or more base stations and repeats all or a subset of the received signals to each of the remote units. And on the reverse link, main unit 115 receives, combines, and repeats the signals from remote units 116 for transmission on the reverse link back to one or more base stations. Each remote unit 116 provides coverage for a particular area (e.g., one floor) of the building and repeats the forward and reverse link signals for its coverage area.
Various challenges are encountered in estimating the position of a terminal located within a building where a repeater may be employed to provide coverage. First, in many indoor applications, the terminals are not able to receive signals from the base stations or GPS satellites, or may receive signals from fewer transmitters than required to perform trilateration. To provide in-building coverage, a repeater typically retransmits a signal from a single base station at relatively high power and with a delay. The combination of the repeated signal's high power plus the isolated indoor location of the terminal normally prevent the terminal from receiving other signals from other base stations and satellites.
Second, if the amount of delay introduced by the repeater is not known, then the signal from the repeater cannot be reliably used as one of the signals for trilateration. This then prevents an entity (e.g., the PDE or terminal) from utilizing the repeated signal to derive a positioning estimate with one less satellite or base station signal. Third, in many environments where repeaters are used (e.g., subways, buildings, and so on) GPS signals cannot be received, even when a terminal employs a receiver unit with enhanced sensitivity. And fourth, the entity used to determine the terminal's position has no way of determining whether the terminal was using an incorrect timing reference (due to the uncertain repeater delay), which would affect the accuracy of the round trip delay (RTD) measurements and the time stamp on the GPS measurements.
There is therefore a need in the art for techniques to provide a position estimate of a terminal in a wireless communication system that employs repeaters (or other transmission sources with similar characteristics).

Method and apparatus for estimating the position of a terminal based on identification codes for transmission sources


A method and apparatus for controlling a brushless direct current motor. An H-bridge is configured to couple a direct current power source to windings of the brushless direct current motor. The H-bridge comprises a plurality of switches. A motor controller is configured to close one of the plurality of switches to put the H-bridge in a coast configuration, wherein the windings of the motor are short circuited. A desired direction for a current impulse to the windings is identified. The one of the plurality of switches is opened in response to identifying a first desired direction for the current impulse to provide the current impulse in the first desired direction to the windings. Another of the plurality of switches is closed in response to identifying a second desired direction for the current impulse to provide the current impulse in the second desired direction to the windings.

1. Field
The present disclosure relates generally to electric motors, such as brushless direct current (DC) motors, and to the control of such electric motors. More particularly, the present disclosure relates to controlling the current in the windings of a brushless DC motor using impulse width modulation.
2. Background
Aircraft may employ various electronic devices and systems to perform various functions on the aircraft. For example, without limitation, electric motors on an aircraft may be used to move flight control surfaces, to raise and lower landing gear, and to perform other functions on the aircraft. Power for the electric motors and other electronic systems and devices on an aircraft may be provided by an aircraft power system.
An example of a type of electric motor used on aircraft, and for many other applications, is a brushless DC electric motor. These types of motors are also known as electronically commutated motors. Brushless DC motors are powered by direct current (DC) electricity and have electronic commutators.
A brushless DC motor has permanent magnets which rotate and a fixed armature which comprises the stator windings. An electronic controller continually switches the phase of power provided to the windings to keep the motor turning. The controller may employ a solid stat circuit to provide timed power distribution to the motor windings.
Because the controller must direct the rotor rotation, the controller requires some means of determining the rotor's orientation relative to the stator windings. Some brushless DC motors use Hall effect sensors or a rotary encoder to directly measure the rotor's position. Others measure the back electromotive force (EMF) in the undriven windings to infer the rotor position. Controllers of this latter type are often called sensorless controllers. Other sensorless controllers are capable of measuring winding saturation caused by the position of the magnets to infer the rotor position.
The controller for a brushless DC motor may provide three bi-directional outputs to control the driving of DC power to the motor windings. The outputs may be controlled by a logic circuit. Simple controllers may employ comparators to determine when the output phase should be advanced. More advanced controllers may employ a microcontroller to manage acceleration, control speed, and fine tune-motor efficiency. Motor controllers of this type may be referred to as electronic speed controllers.
The controller may control the power that is provided to the windings of a DC motor by controlling the switches in an H-bridge. The H-bridge couples the DC power source to the windings of the DC motor. For example, a three-phase H-bridge has six switches for coupling the DC power source to three motor windings of a DC motor. The switches of the H-bridge may be controlled by the controller to drive a current in either direction on each of the motor windings. For example, without limitation, the H-bridge may be implemented using solid state switching devices such as metal-oxide-semiconductor field-effect transistors (MOSFETs).
Various methods may be used to control the switches in an H-bridge to modulate the current in the windings of a brushless DC motor. However, existing methods for modulating the current in the motor windings of a brushless DC motor have drawbacks. A method for controlling the current in the windings of a brushless DC motor that overcomes these drawbacks is desirable.
Accordingly, it would be desirable to have a method and apparatus that takes into account one or more of the issues discussed above as well as possibly other issues.


Methods, systems, and computer programs are presented for lowering network latency for cloud-based services. Service-delivery edge locations allow customers to improve communication-providers public and private network connectivity for improved performance. One method includes operations for performing, by an edge server, a handshake to establish a communication session between a client and a main server, and for exchanging data between the client and the main server via the edge server. The handshake includes exchanging, by the edge server, communication initiation messages with the client, and validating, by the edge server, authentication credentials for the communication session based on the communication initiation messages. The exchanging data comprises forwarding, by the edge server, data requests from the client to the main server through a private connection between the edge server and the main server, and forwarding, by the edge server, data responses from the main server to the client through the private connection.

Some companies rely on the Internet as a communication media for implementing cloud-based services. However, relying on the Internet as the transport medium can result in periods of low-quality service delivery.
The Internet consists of formal and informal agreements among service providers and other institutions which forward traffic, normally with no particular guarantee of an end-to-end service level agreement (SLA). This works surprisingly well most times, until problems arise, such as poor or loss of network connectivity between customers and the service provider.
Network connectivity issues can take many forms: complete loss of connectivity (e.g., at Internet Protocol (IP) level), high latency (e.g., packets arrive much later than expected), packet losses, blocked ports or traffic types, and response variability (e.g., latency at some times can double or triple the latency during good times).
In particular, remote customers accessing servers in faraway locations (e.g., in a different continent) may experience long delays during connection establishment. These delays may be connection establishment procedures like the Transport Layer Security (TLS) handshake process that uses multiple exchanges between the client and the remote server.
What is needed are systems and methods to avoid network latency and provide a robust communications infrastructure.


The present invention provides a piperazine derivative of the following formula or a pharmacologically acceptable salt thereof ##STR1## wherein R.sub.1 represents a benzene ring, naphthalene ring, quinoline ring, indole ring or chroman ring that may be substituted by lower alkyl, lower alkoxy and/or hydroxy; R.sub.2 and R.sub.3 independently represent hydrogen or lower alkyl.. The compound of the present invention has potent antiallergic activity and can therefore be used with advantage in the treatment of various allergic diseases.

1. Field of the Invention
The present invention relates to novel and useful piperazine derivatives, processes for their production, and pharmaceutical compositions and antiallergic compositions comprising said derivatives as active ingredients.
2. Description of the Prior Art
The inventors of the present invention succeeded in synthesizing propanolamine derivatives of the following formula and found that these compounds are of value as antihypertensive and antiglaucoma agents (JP Application H-6-11844). ##STR2## (wherein R.sub.1 represents hydrogen, lower alkyl or lower alkoxy; R.sub.2 represents isopropylamino, tert-butylamino, 2-(2-methoxyphenyl)ethyl-1-amino, 4-(2-methoxyphenyl)-1-piperazinyl, or 4-piperonyl-1-piperazinyl; provided, however, that where R.sub.1 is hydrogen, R.sub.2 is neither isopropylamino nor tert-butylamino and that where R.sub.1 is methyl, R.sub.2 is not isopropylamino).
The inventors of the present invention thence proceeded with further research into the synthesis and pharmacological profile assessment of related compounds. As a result, they synthesized novel piperazine derivatives and discovered that these compounds are of value as antiallergic agents. Based on those findings, the inventors did further research and have perfected the present invention.


A method of manufacturing a semitransparent display device includes the steps of forming a light shield film over a transparent display region on a transparent substrate, applying a photosensitive organic film over the transparent substrate coated with the light shield film, exposing and developing the photosensitive organic film to form a through hole extending through the photosensitive organic film in the transparent display region, removing the light shield film exposed through the through hole after forming the through hole, and forming a reflective film above the photosensitive organic film to form a reflective display region. Thereby, such a situation can be prevented that light reflected by a stage after passing through a TFT array substrate causes visible irregularities in thickness of an organic flattening film during exposure processing for forming the organic flattening film.

1. Field of the Invention
The present invention relates to a method of manufacturing a semitransparent display device and a semitransparent display device, and particularly to improvements in a manufacturing method and a structure of a semitransparent display device, which has a transparent display region and a reflective display region, for increasing a display quality of the reflective display region.
2. Description of the Background Art
Display devices used in portable information terminals called PDAs (Personal Digital Assistants) and portable communication terminals such as cellular phones are required to have thin and light structures, to operate with low power consumption and to achieve high visibility in various environments. Liquid crystal displays, which can inherently achieve thin and light structures as well as low power consumption, have been widely used as the display devices of such portable terminals.
The liquid crystal display device differs from a CRT (Cathode-Ray Tube), a PDP (Plasma Display Panel) and others in that a liquid crystal panel itself, which provides image information, does not emit light. Therefore, the liquid crystal display devices can be roughly classified into two types, i.e., a transparent type allowing passing of light emitted from a light source called a backlight, and a reflective type using a reflector for reflecting incoming external light.
The reflective type can provide a high visibility in a bright place, but cannot avoid remarkably lowing of visibility in a dark place. Conversely, the transparent type cannot provide a high visibility in a bright place, and further requires a larger amount of energy consumption because the backlight consumes a power accounting for a large proportion of the whole power consumption of the liquid crystal display device.
In view of the above, a liquid crystal display device of a semitransparent type has been developed. In semitransparent type, a transparent display region allowing passing of light emitted from a backlight is formed in a portion of a display region, and a reflective display region reflecting incoming external light is also formed in the other portion of the display region. This type of liquid crystal display device having both the features of the transparent and reflective types can provide high visibility in various environments.
In general, a liquid crystal panel includes a TFT (Thin Film Transistor) array substrate, which is provided with a large number of thin film transistors formed in a matrix form on a glass substrate, a color filter, which has color patterns formed on a glass substrate and is arranged over the TFT array substrate, and liquid crystal filling a space between the TFT array substrate and the color filter. This liquid crystal display device performs image displaying by controlling orientation of the liquid crystal within the space.
The liquid crystal display devices of the above type are disclosed, e.g., in Japanese Patent Laying-Open Nos. 2000-29030, 2000-171794, 2000-180881, 2000-284272, 2001-221995 and 2001-350158.
In a process of manufacturing the TFT array substrate of the conventional semitransparent liquid crystal display device, thin film transistors, each of which is formed of a gate electrode, a gate insulating film, a semiconductor layer, a source electrode and a drain electrode, and an interlayer insulating film are formed on a glass substrate. For forming an organic flattening film on the glass substrate, a photosensitive organic material is applied over the glass substrate, and exposure processing is effected thereon.
The exposure as well as development and burning processing are effected on the photosensitive organic material thus applied to form the organic flattening film having through openings in a transparent display region and a contact region. By forming transparent electrodes on the transparent display region, the region can function as a display device of the transparent type. A reflective film may be formed on the organic flattening film and the contact region to provide a reflective display region, whereby this region can function as a display device of the reflective type.
In the processing of exposing the photosensitive organic film, UV (ultraviolet) light is emitted to the transparent display region and the contact region through a photomask to expose only the photosensitive organic film arranged over these regions to the emitted light so that an intended photosensitive organic film can be formed. However, the emitted UV light passes through the gate insulating film made of a silicon nitride film and the interlayer insulating film, further passes through the glass substrate, and reaches a stage carrying the glass substrate.
Therefore, the light reflected by the stage reenters the TFT array substrate through its backside, and exposes the photosensitive organic film. When the photosensitive organic film arranged over portions other than the transparent display region and contact region is exposed to the reflected light, which cannot be controlled by the mask pattern as described above, this results in a problem that the film thickness of the organic flattening film is locally reduced.
Particularly, the stage is provided with grooves, e.g., of about 1 mm in depth for vacuum suction of the TFT array substrate as well as detection portions for various sensors. If the stage has the grooves, light reflected outside the grooves and light reflected inside the grooves have different intensities, and thus reduce the thickness of the organic flattening film by different amounts, respectively. Therefore, the reflective display region, which is provided by forming the reflective film on the organic flattening film, exhibits variations or irregularities in visibility of display due to a difference in reflectance, which is caused by the grooves and others on the stage, so that the display quality lowers.

Transflective display with through hole extending through a light shield in the transmissive region of the display


A method and apparatus for improving the flow control of a shielding gas in a welding unit is described which uses feedback from at least one of a mass flow controller, a pressure sensor and a valve position sensor to regulate shielding gas flow through a controller.

Welding operations often employ the use of inert or semi-inert gases, e.g., helium, argon, carbon dioxide, etc., as a shielding gas to protect the weld area. Air in the weld zone is displaced by a shielding gas in order to prevent contamination of the molten weld puddle. This contamination is caused mainly by nitrogen, oxygen and water vapor present in the atmosphere. As an example, nitrogen in solidified steel reduces the ductility and impact strength of the weld and can cause cracking. In large amounts, nitrogen can also cause weld porosity. Excess oxygen in steel combines with carbon to form carbon monoxide (CO). This gas can be trapped in the metal, causing porosity. In addition, excess oxygen can combine with other elements in steel and form compounds that produce inclusions in the weld metal. When hydrogen, present in water vapor and oil, combines with either iron or aluminum, porosity will result and "underbead" weld metal cracking may occur. Argon, helium and carbon dioxide can be used alone, in combinations or mixed with other gases to provide defect free welds in a variety of weld applications and weld processes.
Metal Inert Gas ("MIG") welding is negatively impacted by excess shielding gas flow rate, and requires minimizing turbulent gas flow to exclude air from the arc. Several devices are used to set shielding gas flow rates. One is used on the cylinder or pipeline gas supply, e.g., a flowmeter with a flow control knob. The knob adjusts a needle valve that lowers the pressure in the gas delivery hose to that needed to achieve the desired flow of shielding gas, typically employing a float ball. Another is only for cylinder gas supply, and employs a very small orifice and varies the pressure upstream of the orifice using a regulator to control flow.
It is important that the flow rate set on the flowmeter or regulator remain at the set value while welding. However, restrictions occur in production which alter flow such as spatter build-up in the MIG gun nozzle, twists occurring in the gas passages in the MIG gun cable, or debris build-up in the conduit passage sections. In an effort to minimize the above variations, choked flow systems were developed. These systems required higher pressure upstream of the restriction of the orifice or valve. However, high pressure causes an initial gas surge, which is undesirable toward achieving high quality welds. In fact, excessively high gas surges at the start of the welding process allows air to be mixed with the gas stream and can cause internal weld porosity until steady state is achieved.
Low-pressure devices equally suffer from problems. These systems typically lack the automatic flow compensation of high pressure devices, and insufficient extra gas at the start of the welding operation causes inferior weld starts.
Overflow as well as underflow from the gas line to the welding torch causes initial weld irregularities, including spatter, porosity, and contamination of the weld. Therefore, it is desired to reduce and/or minimize the variation of shielding gas flow.
Finally, different brands of welding guns and different locations may have different flow characteristics that may further affect the flow of gas. Pressure or volume-based flow controllers do not have means for determining the flow rate that actually passes to the weld site, and therefore variations in flow from a gas source or through the weld gun will not be captured by the flow controller. Therefore, there is recognized a need for an improved gas flow controller that is capable of regulating the flow of a shielding gas to a welding operation, particularly during start-up.


In an image and code data compression apparatus for compressing the image data and further compressing the code data which are compressed from the image data, the apparatus includes: a dividing unit for receiving the image data and dividing them into a plurality of image data blocks; a transformation unit operatively connected to the dividing unit for performing an orthogonal transformation to the image data block and calculating transformation coefficients for every frequency component; a quantizing unit operatively connected to the transformation unit for quantizing the transformation coefficients which are calculated by the transformation unit by using a quantized threshold value which is set commonly to all image data, and calculating the quantized orthogonal transformation coefficients; a coding unit operatively connected to the quantizing unit for performing the variable length coding process for the quantized transformation coefficients which are calculated by the quantizing unit and outputting the code data which are compressed from the image data; a detecting unit operatively connected to at least one of above units for detecting the complexity of the image data block; and a deleting unit operatively connected to at least one of above units and the detecting unit for deleting the block image data having high complexity detected by the detecting unit.

1. Field of the Invention
The present invention relates to an image and code data compression apparatus formed of an image data compression apparatus and a code data compression apparatus. More particularly, the image data compression apparatus is provided for compressing the image data in accordance with an orthogonal transformation and obtaining code data after compression of the image data, and the code data compression apparatus is provided for further compressing the code data in accordance with the orthogonal transformation and obtaining re-compressed code data after compression of the code data.
The image and code data compression apparatus according to the present invention can realize a high data compression rate in accordance with an algorithm for a compression method which is defined by JPEG (Joint Photographic Experts Group).
2. Description of the Related Art
As a method for compressing image and code data using an orthogonal transformation, an algorithm for compression was standardized by JPEG which was jointly organized by the International Standardization Organization (i.e., ISO) and the Comite Consultatif International Telegraphique et Telephonique (i.e., CCITT).
Such an algorithm is described, for example, in "JPEG, DIS 10918 DIGITAL COMPRESSION AND CODING OF CONTINUOUS-TONE STILL IMAGES, PART I REQUIREMENTS AND GUIDELINES". According to this document, image data are divided into a plurality of image data blocks, and each image data block is processed in accordance with a known DCT (Discrete Cosine Transformation) to calculate a DCT coefficient (below, transformation coefficient). Further, the calculated transformation coefficients are quantized to obtain quantized transformation coefficients. Still further, the quantized transformation coefficients are processed, in order, from a low frequency to a high frequency in accordance with a variable length coding process to realize compression of the image data.
In this case, the variable length coding process is performed for data which sums up the number of the quantized transformation coefficients having nonzero value and the number of the quantized transformation coefficients continuing just before the nonzero value.
When improving the above conventional method of image data compression which complies with the JPEG standard, basically, it is necessary to ensure the code data which can decode the image data by using a standardized decoding algorithm to realize an improved image data compression method.

Image and code data compression apparatus


An anti-static sole is provided with a pad body between a midsole and an insole. In the pad body is provided a chip resistor. The chip resistor includes a connecting pin at each of two opposite ends thereof. The two connecting pins of the chip resistor are electrically connected to the insole and the midsole, respectively. Since the chip resistor has no exposed wires, damage to the wires is avoided. Further, the anti-static effect can be improved since the resistance of the chip resistor is stable.

1. Field of the Invention
The present invention relates to a shoe attached with a grounding device, and more particularly to an anti-static sole.
2. Description of the Prior Art
Generally speaking, the phenomenon that charge transfer occurs when an insulator accumulated with charges is brought into contact with a conductor, or charge transfer occurs and potential difference is produced when two objects rub each other is called static electricity. The static electricity generally has no effect on the human body, but it will cause damage to precision equipments such as electronic elements or magnetic memory card. Therefore, the person who processes the electronic elements or the magnetic memory cards must clear the static charges from his body before work. Conductive shoe is one of the existing equipments for eliminating the static charges on the person.
Conventionally, the existing conductive shoe is provided with a ceramic resistor between a midsole and an insole of a sole, and the ceramic resistor is connected to the midsole and the insole, respectively to allow the static charges on the user to be conducted to the midsole through the ceramic resistor and then conducted to the ground from the midsole. By such arrangements, the static charges on the user can be partially eliminated such that the remaining static charges cannot cause any damage to the electronic elements or magnetic memory cards.
However, the ceramic resistor is made up of a middle ceramic portion and two metallic wires at both ends of the middle ceramic portion, and the connecting structures for connecting the ceramic portion and the two metallic wires are quite fragile, so that after being bent for many times or pressed for a long time, the metallic wires will be damaged or even broken, and the ceramic portion is likely to rupture due to overlarge pressure applied by the user. If the user finds the above defects, he must replace his shoes, but if the user fails to find the above defects, the static charges on the user cannot be eliminated properly, inevitably causing damage to the electronic elements or magnetic memory cards.
Hence, U.S. Pat. No. 6,421,222, entitled "PRECISION FAIL-SAFE ELECTROSTATIC DISSIPATING DEVICE", disclosed an apparatus for dissipating static charges which is constructed of several conductive layers and a set of parallel resistors, if either resistor of the parallel resistor fails, the static charges can also be dissipated through the remained resistors, ensuring fail-safe dissipation of static electricity, but it can be found that the production cost is greatly increased due to the increase of the number of the resistors.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.


A thin film solar cell having high conversion efficiency is provided. The band gap of the thin film solar cell can be controlled while keeping the quality superior to conventional solar cells. The absorber layer for photovoltaic energy conversion is a Cu(In.sub.1-X Ga.sub.X)(Se.sub.1-Y S.sub.Y).sub.2 based solid solution where X and Y are in the range of the following Equation: EQU 0.317+0.176Y.gtoreq.X.gtoreq.0.117+0.176Y EQU 1>X+Y>0 EQU Y>0,. The Cu(In.sub.1-X Ga.sub.X)(Se.sub.1-Y S.sub.Y).sub.2 based solid solution has a specific chalcopyrite type crystal structure and its lattice constant ratio of c-axis to a-axis is extremely close to two. It is most preferable that the band gap is 1.4 eV, X is 0.3, and Y is 0.4, since the conversion efficiency of a homojunction solar cell will then become a maximum.

A thin film of a I-III-IV.sub.2 type compound whose band gap ranges from 1.0 to 1.8 eV, such as CuInSe.sub.2, is used as an absorber layer in solar cells. Multi-source evaporation and selenization are known as methods for forming a CuInSe.sub.2 thin film (cf. A. Rockett and R. W. Birkmire, J. Appl. Phys. Vol.70, No.7, p.81). In the multi-source evaporation, a CuInSe.sub.2 film is formed on a heated substrate by evaporating the elements (Cu, In, and Se) from the respective evaporation sources. Several well-known evaporation processes, which provide highly efficient solar cells, include a process for forming a Cu--In--Se film in a Cu-rich composition (Cu/In>1). The reason is as follows. If a thin film is formed on a substrate at a temperature of at least 500.degree. C. in a Cu-rich condition for the composition, Cu--Se based impurities are deposited as well as the CuInSe.sub.2. The Cu--Se based impurities function as a flux, and thus the crystal particles of the CuInSe.sub.2 grow bigger. In another case, the band gap (Eg) of the CuInSe.sub.2 (absorber layer) is made closer to the best value for absorption of sun light (1.4 eV), so that the efficiency of the solar cell is improved. In general, the band gap of the absorber layer is increased by dissolving CuGaSe.sub.2 (Eg=1.68 eV) in the CuInSe.sub.2 (Eg=1.0 eV).
When Cu(In.sub.1-X Ga.sub.X)Se.sub.2 solid solution is used for an absorber layer, the band gap will be enlarged as the quantity of Ga solid solution (X) rises. The conversion efficiency of the solar cell, however, does not increase so easily even if the solid solution thin film is used for the absorber layer. The conversion efficiency is maximum when the quantity (X) of Ga is about 0.2 to 0.3 (Eg=about 1.15 eV). The conversion efficiency, however, starts lowering if the value (X) continues to rise (cf. H. W. Schock, MRS BULLETIN, Vol.18, No.10, p.42-44). This phenomenon is caused, probably, by the deterioration of the crystal property of the Cu(In.sub.1-X Ga.sub.X)Se.sub.2 solid solution thin film in a Ga-rich region.

Thin film solar cell and method for manufacturing the same

Matsushita Electric Industrial Co., Ltd.


A laundry treating machine includes a case, a tub, a drum, a drain pump housing, and a drain pump motor, wherein a plurality of fastening protrusions that are formed at one of the drain pump housing and the drain pump motor are inserted into a plurality of fastening grooves that are formed at the other of the drain pump housing and the drain pump motor, and wherein a length of one fastening protrusion is formed to be different from lengths of the other fastening protrusion such that the drain pump housing and the drain pump motor is prevented from being assembled wrongly.

In general, a laundry treating machine is a device that washes laundry by rotating a cylindrical shaped drum containing laundry and wash water therein. There are two types of the laundry machines. One is a front loading type washing machine of which a drum is disposed horizontally, and when the drum is rotating in a forward and reverse directions with respect to a horizontal axis, the laundry is raised upside and dropped along the inner circumferential surface of the drum. Another is a top-loading type washing machine which washes laundry by water flow generated when a pulsator disposed in a drum is rotating in the forward and reverse directions, wherein the drum is disposed in a vertical direction.
Most generic laundry treating machine comprises a cabinet that forms the exterior appearance, a cylindrical tub that contains washing water and is disposed in the cabinet, and a drum that rotatably disposed inside of the tub, and washes laundry put in the drum by rotating the drum. This laundry treating machine comprises a water supply-system for supplying washing water and a drainage system for draining washing water after washing laundry is finished. The drainage system includes a drain hose to washing water outside and a drain pump that is located in the lower part of a water tank and generates power for pumping wash water to be drained.
The drain pump is located in the lower part of the tub and drains the water discharged from the tub. An electric power is supplied to the drain pump from a terminal and drives drain pump motor. However, a lower space of the laundry treating machine may be sunk under water in case that water is spilling over the laundry treating machine. Therefore, it is desired that the terminal that supplies the electric power from off-site is placed on an upper side of the drain pump motor to prevent an electric shock.
When fastening means, that fastens the drain pump motor where a terminal is installed and the drain pump housing where drained water flows, simply performs the function of fastening without being arranged in a predetermined position, the arrangement of the terminal could be changed in the process of fastening the drain pump motor and drain pump housing, and in some cases, the problem that the terminal is placed in the lower part of the drain pump motor may be occurred.


An apparatus including only first and second sensors for determining three phase motor currents and providing complete over-current protection to a three phase motor having three input lines. The first and second sensors measure first and second combined currents wherein the first combined current is the current through the first and second lines and the second combined current is at least the current through the second line and at least one of the first or second combined currents include the third current. The first and second combined currents are used to provide the over-current protection and are used to determine all of the first, second and third line currents.

The present invention relates to motor controls and more particularly to a two current sensor assembly for determining three phase current values and for providing over-current protection.
Many motors include three phase windings driven by a controller which provides three phase AC currents to the three windings via three separate AC supply lines. To provide controlled operation, many control systems include closed loop current feedback so that motor operation can be monitored and adjusted accordingly.
In addition, many systems come equipped with over-current protection circuitry to minimize the effects of short circuited supply lines. To this end, over-current protection circuitry typically includes a means for monitoring all three line currents and means for shutting off the line currents when a current irregularity is identified. When one of the line currents exceeds a predetermined threshold value, the circuitry recognizes the possibility of a short and shuts off current to all three motor phases effectively stopping the motor until the cause of the irregularity is identified.
The easiest way to provide current feedback for both motor control and over-current protection is to provide three current sensors, a separate sensor on each of the three supply lines. Currents sensed via the three sensors is provided to the over-current protection circuitry and the controller generally to facilitate over-current protection and motor control, respectively.
Typical current sensors used in the motor controls art include Hall effect sensors. A Hall effect sensor typically forms a passageway through which one or more lines can be passed. The sensor senses the total current passing through the passageway and provides an electrical signal indicative thereof.
While the three sensor solution is robust and easy to understand, unfortunately current sensors are relatively expensive. Therefore, it is desirable to use fewer than three sensors when possible.
To this end, some systems have been designed which are capable of measuring two line currents and deriving the third line current therefrom. It is well known that the sum of currents passing through the three supply lines should equal zero. Thus, if the first and second line currents are sensed, during normal operation the third line current can be determined by taking the negative of the sum of the first and second currents. Here, all three line currents can be derived for control purposes using only two Hall effect sensors.
Unfortunately, where only two line currents are measured and the third current is derived, the derived current may not reflect a fault to ground in the third line. This is because a connection to ground in the third line with a relatively high impedance may not significantly affect the currents in the first and second lines.
If a short occurs in a third line and is not detected because the third line current is derived via the first and second sensed currents, the over-current circuitry cannot operate properly to shut off current to the three phases and motor damage or operator injury may result.
Thus, it would be advantageous to have a current sensing apparatus wherein all currents in a three phase motor system can be derived using less than three current sensors and complete over-current protection can also be provided via the sensed currents.

Two sensor for over-current protection and current sensing configuration motor control


Certain example embodiments described herein relate to techniques for determining the effectiveness of social media content posted to a particular network location. An example technique includes receiving a set of social media content records posted to a network location and one or more user reaction records posted in response to the social media content record, associating at least one emotion token with each received user reaction record, assigning at least one emotion category to each social media content record, obtaining one or more engagement metrics for each social media content record, and determining a relationship between at least one engagement metric and at least one emotion category based upon the obtained one or more engagement metrics and the assigned at least one emotion category of respective social media content records in the set.

Social media systems are pervasive throughout modern society. Social media platforms such as Facebook®, Twitter®, Youtube®, blogs, Instagram® and the like, exist entirely on, and because of, the Internet. They present corporations and other entities with opportunities and problems that have no parallel outside of the computer networks on which they exist. Entities such as corporations and individuals use social media platforms to engage in conversations and to convey their views to their respective audiences. Companies extensively use social media platforms, such as those mentioned above, to advertise products and services, to convey their views on certain social and other issues, etc. In the various social media systems, an initial post of some particular content by a user or company often causes other users accessing that content to react by posting one or more comments associated with the initial post. The reactions of users to the various posts made to social media platforms by a corporation can yield information of high value.
The continuing growth of accessibility to the Internet in populations throughout the world, and the continued growth in both the number of people using mobile devices to access the Internet and the frequency with which people use mobile devices and the like to access the Internet, are driving an explosive growth in the level of engagement an entity's audience has with that entity's social media presence. Corporations and other entities now compete for "eyeballs" on their social media presence. As the manner in which audiences consume advertising and other information shifts away from conventional avenues such as radio, television, newspapers and other print media, to social media platforms, it becomes more important that corporations and other entities have effective techniques by which to efficiently and accurately determine the level of user engagement associated with their social media presence.

Systems and methods for estimating and/or improving user engagement in social media content


An apparatus for detecting an electrostatic force in a solution includes a sample and a cantilever. An end of the cantilever is conductive and has voltage applied to it. The apparatus detects electrostatic interaction caused by functional groups of target molecules in the solution.

1. Field of the Invention
The present invention relates to an apparatus for detecting an atomic force in water, particularly an atomic force based on an electrostatic interaction.
2. Description of the Related Art
The development of a scanning tunneling microscopy (STM) has recently brought about a marked improvement in means for observing the microscopic surface structures of various types of sample surfaces. The STM is an instrument for imaging individual atoms on a sample surface one by one by monitoring tunnel currents flowing between the metal tip and the sample surface. The STM is basically used to observe metals and semiconductors having high conductivity. For samples having low conductivity, an atomic force microscopy (AFM) for detecting an atomic force acting between the tip and the sample surface is used to observe surface structures at the atomic level. Actually, the AFM is used to obtain an image of each atom on the surface of an ionic crystal such as NaCl or a lamellar substance such as mica or graphite.
Objects to be observed by the STM and the AFM are not limited to inorganic materials such as semiconductors and metals but tend to include organic molecules such as benzene and phthalocyanine and biological molecules such as proteins and DNAs. Attempts to observe the surfaces of such substances have been reported. Since there is no appropriate means for estimating the structures of biological molecules, the three-dimensional structures of many kinds of molecules are not yet known. If, therefore, surface structures can be detected by the STM and the AFM, it will greatly contributes to analysis of three-dimensional structures. In the state-of-the art techniques, however, observation of organic molecules and biological molecules by means of the STM and the AFM still entails various problems.
Organic molecular images obtained by the STM and the AFM are very obscure as compared with semiconductor and metal images which allow discrimination of the structure of each atom. Especially when a biological molecule is imaged, the overall structure image of the order of several nanometers can be only vaguely seen, but the structures of atoms cannot be discriminated from each other. In addition, reliable observation conditions are not established yet. For example, when a molecule surface is wet, an image can be obtained. If, however, the surface is dry, no image can be obtained. Furthermore, the reproducibility of images is poor.
The followings are considered as the reasons for such problems. It is basically difficult to apply the STM to samples other than those having high conductivity. Since organic molecules and biological molecules have low conductivity, theoretically, no tunnel currents should flow and no molecule images should be obtained. It therefore seems that obscure molecular structure images obtained by the STM up to the present are not attributable to tunnel currents between the tip and a molecule but are based on currents generated by some other factors. Although a definitive explanation for the generation mechanism of these currents is not yet forthcoming at present, it is highly probable that the generation of the currents is associated with thin water layers and the like which are considered to exist on molecular surfaces. Even if currents generated by such a mechanism are monitored, it is impossible to detect molecular structures at the atomic level.
Currently, the AFM is operated under the condition that a large repulsive force of 10.sup.-7 to 10.sup.-8 N acts between the tip of the cantilever and a sample. However, since an organic molecule or a biological molecule is structurally weaker than an inorganic material, if the AFM is operated under the above-mentioned condition, there is a high possibility that structural deformation or destruction of the molecule is caused. Therefore, even if an image is obtained, it is impossible to distinguish whether the image represents the inherent structure of the molecule or the structure deformed by the repulsive force.
As described above, although attempts are made to observe the structures of organic molecules and biological molecules by using the STM and the AFM, these instruments are not basically suitable for the estimation of those molecules at the atomic level. Therefore, demands have arisen for means capable of estimating molecular structures at the atomic level on the basis of the principles applicable to the physical properties of molecules.
A very distinct characteristic feature associated with the structures and physical properties of organic molecules and biological molecules is that these molecules contain functional groups, and the physical properties and functions of the molecules are greatly influenced by the bonding positions of the functional groups. Typical functional groups are --COOH, --NH.sub.2, --OH, --CONH.sub.2, --SH, and the like. A functional group is a minimum unit exhibiting the function of a molecule. The function of a functional group is determined by its electrical property, more specifically a charged or polarized state. For example, the group --COOH is an acidic functional group which tends to be negatively charged to become --COO.sup.- in water. The group --NH.sub.2 is a basic functional group which tends to be positively charged to become --NH.sub.3.sup.+ in water. Although the groups --OH, --CONH.sub.2, and --SH are not apt to be ionized in water, these functional groups themselves have large dipoles.
Since the functional groups are ionized or have large dipoles in this manner, they cause a strong electrostatic interaction with their surroundings. A typical example of such an interaction is one caused by protein. Protein consists of 20 types of amino acids. The amino acids are combined to each other to constitute a one-dimensional chain structure, and this chain structure constitutes a complicated stereoscopic structure. In water in which a protein exhibits its function, the functional groups of the amino acids being ionized or having large dipoles are exposed on the protein surface. It is considered that the charge distribution based on the functional groups is closely related to the stereoscopic structure of the protein or the molecular function inherent in the protein, typically an enzyme reaction. In spite of the fact that the charge distribution on a protein surface and the surrounding electric field distribution based on the charge distribution are important, there are no measurement means for such distributions.
A great deal of attention is paid to techniques associated with the STM and the AFM as promising candidates for means for measuring an intramolecular charge distribution based on functional groups in a solution and a surrounding electric field distribution at the atomic level. For example, electrochemical AFM (S. Manne et al., Science, 251, 183-186 (1991)), EMF (electrostatic force microscope) (B. D. Tetris et al., Phys. Rev. Lett., 63, 2669-2672 (1989); B. D. Tetris et al., J. Vac. Sci. Tech., A8(1), 374-377 (1990)), and IFM (interfacial force microscope) (S. A. Joyce et al., Rev. Sci. Instrum., 62, 710 (1991)) have been proposed. These associated techniques, however, cannot achieve the above object for the following reasons.
The electrochemical AFM is an instrument designed such that an electrode system electrochemically controlled is formed in water to observe the microscopic structure of a metal sample surface. In the electrochemical AFM, a three-electrode system is constituted in a sample cell by a metal sample as a working electrode, a stainless clip as a counter electrode which holds a cantilever, and a copper wire as a reference electrode, and the potential of the metal sample surface is controlled by the three-electrode system. Similar to the general AFM, this electrochemical AFM is designed to detect a repulsive force acting between the cantilever and a metal sample surface but cannot measure a charge distribution or a potential distribution on the sample surface. In addition, since the copper wire is used as the reference electrode, currents flow between the reference electrode and the working electrode and between the reference electrode and the counter electrode. This makes it difficult to perform accurate potential control, and various kinds of electrode reactions are caused.
The EFM is designed to measure an electrostatic force acting between a metal cantilever and a metal sample surface. The EFM, however, is designed to perform measurement in the air or in a vacuum, and does not have a cell for holding the cantilever and the sample in water. In addition, in the EFM, the cantilever is vibrated at a frequency near its resonance frequency, and the electrostatic force is detected on the basis of changes in amplitude, phase, and frequency of the vibrations. The reason why the method of vibrating the cantilever is employed is that the EFM is designed to detect a force acting in a region located 10 to 100 nm apart from the sample. In water, however, since water has a high relative dielectric constant of 80, the electrostatic force is very small in a region located 10 nm or more apart from the sample. For this reason, in water, the force must be detected in a region apart from the sample by only several nanometers. In this case, the cantilever vibration method cannot be used because the cantilever may collide with the sample. Furthermore, in the EFM, a voltage is applied between the metal cantilever and the metal sample. If this method is used in water, since water has high conductivity, a current flows in water. Consequently, various kinds of electrode reactions, e.g., the decomposition of water on the sample surface and the cantilever surface, are caused to hinder detection of the electrostatic force. Therefore, when the electrostatic force is to be detected in water, a method in which no current flows upon application of a voltage must be employed.
The IFM is an apparatus designed to measure a minute force, especially an attractive force, acting between the tip and the sample which are spaced apart by a short distance of a few nanometers or less. In an AFM of ordinary type (including an EFM and an electrochemical AFM), when an attractive force acts between the tip and the sample, the cantilever will be pulled toward the sample, causing a phenomenon known as "jump-in," and will come into contact with the sample, if the gradient of the attractive force surpasses the spring constant of the cantilever. The range over which the attractive force can be measured is inevitably limited. With the IFM it is possible to measure an attractive force built up between the tip and the sample which are spaced apart by such a short distance, without causing jump-in. This is because a capacitor is provided, one of the electrodes of which is the back surface of the cantilever, and the attractive force between these electrodes is controlled by voltage, thereby canceling out the tip-sample attractive force. An electrostatic force between the tip and the sample has not been measured in the IFM-related experiment and research hitherto reported. It is, nonetheless, possible to measure an electrostatic force in the atmosphere or in a vacuum if a metal tip is used as in the EFM. If the IFM is used in an aqueous solution, however, the attractive force acting between the electrodes of the capacitor, which are spaced apart by a few tens of microns, is screened by water and thereby decreases to so small a value that it can no longer cancel out the tip-sample attractive force. The IFM has another problem that a current flows between the electrodes of the capacitor, resulting in various electrode reactions on the electrode surfaces, which in turn render the IFM operation unstable. Hence, it is basically problematical to employ the IFM in a solution in order to evaluate intramolecular charge distribution based on functional groups.
As described above, at present, there is no appropriate means for estimating the structures of organic molecules and biological molecules at the atomic level. In spite of the fact that the functional group distribution and charge and potential distributions based on the functional groups play important roles in terms of the physical properties and functions of the molecules especially in a solution in which the molecules exhibit their functions, there is no means for measuring them. Although techniques associated with the STM and the AFM are promising as means for estimating the functional group distribution, the charge distribution, and the potential distribution, they have various kinds of problems and hence cannot achieve the above-described object.

Apparatus for estimating charged and polarized states of functional groups in a solution


The present disclosure relates to a method of use during arthroscopic surgery. The method includes inserting a cannulated needle into a joint area of the body, inserting a guidewire through the needle, removing the needle, and inserting an arthroscopy knife into the joint area via the use of the guidewire. An arthroscopy knife and another method of its use is also disclosed.

1. Field of Technology
The present disclosure relates generally to arthroscopic surgery and, specifically to a device and methods for use during arthroscopic surgery.
2. Related Art
During hip arthroscopy, it is often necessary for a surgeon to use an arthroscopy knife to make incisions that will allow the surgeon to gain access to areas near the hip joint. For example, the knife may be used to detach the labrum from the acetabular rim. During the same procedure, the knife may be used to make an incision in the hip capsule. Using the knife to detach the labrum from the acetabulum has its drawbacks because the point at which the knife will exit the labrum is not known prior to making the cut. Therefore, a knife and specifically, methods of use that allow for more precision control of the knife are needed.

Device and methods for use during arthroscopic surgery


The image signal band compressing method employs a three-dimensional motion compensating technique, an intraframe and an interframe processes which are alternatively executed. The transfer rate of the intraframe to the interframe is set to 4:1 in a unit of fixed length. The intraframe process is defined such that the present frame image data is compressed in a variable length compressing manner by way of two-dimensional discrete coding transform. The interframe process is defined such that motion data is estimated by comparing the present frame and the preceding frame, the present frame is expected on the basis of the motion data and the difference data between the motion compensated image data and the present frame data.

1. Field of the Invention
The present invention relates to a video image signal band compressing system for a digital video tape recorder (D-VTR) of a high picture quality.
More particularly, the present invention relates to a video image signal band compressing system which digitally converts a component image signal as a signal source and compresses the digitally converted signal in a unit of fixed length depending upon a human visual property and a statistical nature and frequency distribution of the image to execute a additional high speed playback of the D-VTR.
2. Description of Related Art
With a recently advanced technique in the fields of a computer, a semiconductor device and a digital signal processing system, a storage and transfer of a digitized signal is also developed remarkably.
When such an image signal is stored or transferred in digital, a massive amount of the image signal must be processed as compared with an analog data, so compression of the image data is needed to effectively utilize a capacity of a storage medium and a data transferring channel. Accordingly, it requires that the image data must be compressed in a given amount while completely representing original information contents. Further, the image data compressed has a reliable characteristic to an error occurred in a storage medium and a hardware for compressing in image data must be easily embodied.
According to a typical image signal band compressing system, the image signal is divided into several blocks and the blocked image signal is subjected to a variable length coding achieved by way of a transform coding technique, for example, a discrete cosine transformation (DCT). In the image signal coding using such a DCT technique, since energy of the image signal is condensated on a low frequency portion, the original information can be reliably represented using a small quantity of data by coding the low frequency region of the image signal.
According to the aforementioned variable length coding technique, a codeword of given data is variably assigned with reference to the probability density of the image data and the codeword having variable length is transferred. This technique is suitable to apply when the image data to be processed are not uniformly distributed.
Therefore, the variable length coding technique assisted by the DCT coding can be effectively employed to reliably express the ununiformely distributed image data.
According to the technique denoted above, however, only local property of the image is considered in the image data coding. When the complex image signal having a fluctuating region and a flattening region of the image data is subjected to the previously noted coding in the D-VTR which compresses the image signal into a target amount of data in unit of a fixed length, and transfers and stores the compressed image signal, surplus data produced in processing the flattening region are not sufficiently utilized, so that serious deterioration of the picture quality in a portion adjacent to the flattening region and the fluctuating region is occurred undesirably.
In the variable length coding of the image data, it is required to a constant amount of data per a unit time duration in order to store or transfer the data coded. Accordingly, a buffer is needed to temporarily store the coded data and a step size of quantization must be controlled by a buffer pre-control or buffer post-control technique to adjust the amount of the data produced.
While such a buffer pre-control technique has an advantage that an error in the storage medium is propagated in a unit of fixed data length, it is difficult to adjust the amount of the data produced in a unit of fixed length to the desired amount of data.
On the contrary, according to the buffer post-control technique, such a step size in the quantization is decided in accordance with the repleted degree of a buffer under periodic confirmation of the status of the buffer. Accordingly, the amount of the data to be stored or transferred is coincided with the desired amount of data. Plus it has a block effect occurred due to a quantization error when the fluctuating region adjoins the linear region.

Image signal band compressing system for digital video tape recorder


A fastener system for fastening the components of a plastic unit which has a U-shaped clip with an aperture therethrough, a walled cavity to receive the clip, and a machine screw. The walled cavity is molded onto the host portion of the plastic unit and has a low mass, which precludes the formation of sink marks and holes on the plastic unit. The U-shaped clip rests upon the walled cavity and has barbs that bite into the walls securing the clip in place. The machine screw is inserted into a housing on the joined portion of the plastic unit and is mated with a lead thread on the aperture of the clip. The metal-to-metal contact of the machine screw and clip permits repetitive assembly and disassembly of the plastic unit. The clip is readily removable for recycling the plastic of the unit.

1. Field of the Invention
This invention relates to a fastening system for assembling plastic units and more particularly to spring steel clips for retaining attaching hardware in the assembly of molded plastic structures. The clips are utilizable with corresponding plastic receptors, such as ribs, which ribs, when employed in lieu of tubular plastic posts or bosses, avoid the occurrence of sink marks and sink holes opposite the attachment site. The clips of this invention also support repetitive assembly and disassembly.
2. Description of Prior Art
The connecting of large- or medium-scale molded plastic parts to one another has been fraught with technical problems for many years. In the 1940's, Tinnerman developed a fastener and a fastener company, Tinnerman Products, Inc., which aided assembly of such parts by the introduction of the Tinnerman nut. Tinnerman's success is memorialized by several patents including U.S. Pat. Nos. 2,326,579 and 2,344,570.
In many applications the boss-caused sink marks and sink holes are irrelevant as the sink holes do not interfere with the functionality or esthetics of the product and as the products are not routinely cleaned or sterilized. However, with products requiring highly esthetic finishes and fine cosmetic appearance, smooth surfaces without valleys or dimples are significant. Of course, in medical and personal hygiene products such surfaces are important as cleaning and sterilization are facilitated thereby.
In the design of modern-day plastic assemblies, attention is drawn to the overall recyclable aspects thereof. Where assemblies with molded-in-place brass inserts are used, recycling becomes difficult because of the salvage labor required to remove the inserts. Thus, in mis-manufactured plastic parts where an insert has been missed or insufficient resin is supplied to the mold or a color defect exists, regranulation becomes uneconomic. The use of metal inserts, while permitting repetitive assembly and disassembly, still remains problematic with regard to recycling and regranulation of waste plastic.
Another fastener arrangement, as shown in Levey et al, U.S. Pat. No. 6,976,818, assigned to Illinois Tool Works Inc., is the plastic boss and the corresponding screw. Here, without using an insert, an interlocking screw is driven into the plastic and cuts a swath in the plastic body of the boss. Various thread designs are known in the art and are configured for cutting and interlocking with the boss. Each time the plastic assembly is assembled and disassembled, additional cutting takes place. Unlike the metal insert discussed above, the plastic boss and screw fastener arrangement does not support repetitive assembly and disassembly.
The designing of bosses for mounting purposes is an inexact science that has given rise to numerous rules of thumb for avoiding sink marks and holes. Such rules provide: (1) the boss height should not be more than twice the diameter; (2) a radius should be provided where the boss joins the wall; and, (3) the boss diameter should be smaller in dimension than the thickness of the wall. While all the rules are helpful in enabling the mold designer to practice his art, the underlying problem is maintaining a suitable low mass of plastic for mounting purposes on one side of a plastic wall to avoid sink marks and holes on the other side.
As the automotive industry developed, many spring clips were designed to enhance assembly line operations. Among the earliest were those of Fred S. Carr and United-Carr Fastener Corporation which corporation worked closely with Fisher Body. Typical of the devices is the invention of F. E. Johnson, U.S. Pat. No. 2,295,480 providing a nut mounted on a clip for assisting panel mounting. A Ford Motor Company development provided a sliding clip of W. D. Gaw Jr, U.S. Pat. No. 5,536,125 to enable axial alignment. More recently, in a patent to L. P. Tanner, U.S. Pat. No. 6,796,760 a retention clip is disclosed. This U-shaped clip has a holding arm restraining lateral movement of a captive fastener during shipment of a panel (with fasteners held thereon).
In the course of preparing for this application, the inventor hereof became aware of the following patents:
U.S.Pat. No.InventorIssue Date6,976,818Levey et al.Dec. 20, 20056,899,499Dickinson et al.May 31, 20056,848,874Lowry et al.Feb. 1, 20056,796,760TannerSep. 28, 20046,283,689Roytberg et al.Sep. 4, 20015,855,461TripiJan. 5, 19995,536,125Gaw, Jr.Jul. 16, 19963,400,743StrangeSep. 10, 19682,344,570TinnermanMar. 21, 19442,326,579TinnermanAug. 10, 19432,295,480JohnsonSep. 8, 1942The patents not mentioned hereinabove are considered briefly below.
Dickinson et al—U.S. Pat. No. 6,899,499—issued May 31, 2005 Dickinson '499 discloses a fastener that snaps into a slot-containing structure attached to the host portion of the unit being attached. The structure required to snap the fastener into place necessarily has a high mass, running a high risk for sink marks and holes. The metal fastener thereof is not readily removable for the recycling of the plastic.
Lowry et al—U.S. Pat. No. 6,848,874—issued Feb. 1, 2005 Lowry '874 discloses a spring fastener with a configuration of barbs that allows for the extraction of the fastener without the destruction of the slot or the fastener. However, since the fastener must be installed in a slot, the construction that would be required to use such a fastener in the present application, without puncturing the host portion of the plastic unit, would necessarily have a high mass, thereby causing the formation of sink marks and holes on the opposite side of the wall.
Tanner—U.S. Pat. No. 6,796,760—issued Sep. 28, 2004 Tanner '760 discloses a retainer for a captive fastener during transportation thereof. It is suitable for application to automotive technology, particularly for panels with pre-inserted fasteners, which do not require repetitive insertion and removal.
Roytberg et al—U.S. Pat. No. 6,283,689—issued Sep. 4, 2001 Roytberg '689 discloses a one-piece insert fastener with outwardly protruding wings, which wings are secured within an aperture in the outer surface of a panel.
Tripi—U.S. Pat. No. 5,855,461—issued Jan. 5, 1999 Tripi '461 discloses an anchor for securing a threaded fastener, which provides for repetitive assembly and disassembly, and is suitable for application to automotive technology, particularly for panels. The anchor of this invention is for mounting in a circular hole.
Gaw, Jr.—U.S. Pat. No. 5,536,125—issued Jul. 16, 1996 Gaw Jr. '125 discloses a fastening assembly for securing plastic panels to metallic substrates. As part of the fastening assembly, a nut is snap-fit mounted to a plastic insert, which plastic insert in turn is snapped into the substrate. The fastening assembly is suitable for application to automotive assembly and provides for repetitive assembly and disassembly.
Strange—U.S. Pat. No. 3,400,743—issued Sep. 10, 1968 Strange '743 discloses a fastener that includes a screw and a sheetmetal nut holder with resilient arms. The retention force of the resilient arms results from the screw insertion and spreading of the arms thereby. Thus, upon the removal of the screw, the nut is freed.
Johnson—U.S. Pat. No. 2,295,480—issued Sep. 8, 1942 Johnson '480 discloses a nut device that requires a hole for installation of the nut. Thus, for use in the present application, where a puncture is to be avoided, the molding of a boss is required.
In viewing the prior art, several fastener system and fastener characteristics have been considered, namely: (1) the likelihood of the formation of sink marks and sink holes on the plastic unit being assembled; (2) the effect of repetitive disassembly and reassembly on the structure; and, (3) the ease of recapturing and regranulating plastic from mismanufactured units. None of the above configurations satisfy all of these desired criteria.
It will be seen that the rib clip of this invention both considered alone and together with the other components of the fastener system provide an answer to the long felt need expressed by the above criteria.

Fastening system for assembling plastic units and rib clip therefor


A regenerator (7.x, 7.1-7.3) for regenerating optical signals on optical transmission links (4), in particular for use in a Dense Wavelength Division Multiplex (DWDM) optical transmission system. The regenerator (7.x, 7.1-7.3) comprises optical amplification means (7.xa, 7.xd) for compensating optical power losses, and a deterministic adaptation unit (7.xb) comprising means being adapted to compensate deterministic transmission impairments of the optical transmission link (4), in particular optical dispersion compensating means being adapted to compensate for chromatic dispersion of said link (4). The proposed regenerator (7.x, 7.1-7.3) further comprises a non-deterministic adaptation unit (7.xc) comprising means for compensating time variant non-deterministic transmission impairments, in particular polarisation mode dispersion. In this way, the proposed regenerator overcomes transmission limitations and improves robustness of long and ultra-long-haul multi-span DWDM transmission systems with respect to deterministic and non-deterministic transmission impairments.

The present invention also relates to an optical signal transmission system, comprising at least one transmitter, at least one receiver, and an optical transmission link connecting the transmitter with the receiver, as well as to a method for regenerating optical signals in at least one location along an optical transmission link, in particular in a Dense Wavelength Division Multiplex (DWDM) optical transmission system, comprising the steps of: amplifying the optical signal for compensating optical power losses, and compensating deterministic transmission impairments, in particular chromatic dispersion, of the optical transmission link.
Current (ultra-)long-haul multi-span DWDM optical transmission systems are usually equipped with inline 2R-regenerators (optical fibre amplifiers—OFA) for recovering the optical power level of the DWDM channels in order to improve the link power budget. In some cases, said 2R-regenerators are combined with inline dispersion compensation means in the form of dispersion compensation fibres (DCF) for the adaptation of deterministic residual chromatic dispersion of the link. In the present context, the term "deterministic" generally refers to effects which are foreseeable and predictable with respect to the used transmission wavelengths, the link fibre material, the span length, etc., as is the case with chromatic dispersion. Both functions mentioned above are usually combined in so-called dispersion compensation units (DCU) including an input optical amplifier for compensating the preceding link losses, i.e., power losses induced by preceding fibre spans, an interstage dispersion compensating fibre (DCF), and an output optical amplifier for compensating the DCF losses and for adapting the signal output power level.
However, conventional inline 2R-regenerators are not capable of managing/controlling time variant, e.g. statistically fluctuating, transmission impairments, such as polarisation mode dispersion (PMD) or temperature dependent chromatic dispersion variation on (ultra-)long-haul DWDM links. Such time variant transmission impairments will hereinafter also be referred to as "non-deterministic" dispersion or distortion effects, since they may be foreseeable while generally being unpredictable.
Optical receivers used in transmission systems of the above-mentioned type are usually equipped with forward error correction (FEC) means in order to improve the system margins and to overcome the tight optical signal-to-noise (OSNR) limitations of high bit rate (ultra-)long-haul transmission systems. However, due to the unpredictable, statistically fluctuating signal distortions mentioned above, which may among others be caused by polarisation mode dispersion (PMD), unacceptable error bursts may occur during one FEC frame, thus leading to a system outage in DWDM systems equipped only with conventional 2R-regenerators.

Optical signal regenerator and transmission system