A subband audio coder employs perfect/non-perfect reconstruction filters, predictive/non-predictive subband encoding, transient analysis, and psycho-acoustic/minimum mean-square-error (mmse) bit allocation over time, frequency and the multiple audio channels to encode/decode a data stream to generate high fidelity reconstructed audio. The audio coder windows the multi-channel audio signal such that the frame size, i.e. number of bytes, is constrained to lie in a desired range, and formats the encoded data so that the individual subframes can be played back as they are received thereby reducing latency. Furthermore, the audio coder processes the baseband portion (0-24 kHz) of the audio band-width for sampling frequencies of 48 kHz and higher with the same encoding/decoding algorithm so that audio coder architecture is future compatible.

1. Field of the Invention
This invention relates to high quality encoding and decoding of multi-channel audio signals and more specifically to a subband encoder that employs perfect/non-perfect reconstruction filters, predictive/non-predictive subband encoding, transient analysis, and psycho-acousti c/minimum mean-square-error (mmse) bit allocation over time, frequency and the multiple audio channels to generate a data stream with a constrained decoding computational load.
2. Description of the Related Art
Pulse code modulation (PCM) based speech coders were first developed in the 1960""s. In the early 1970""s, low bit-rate speech coders were developed for use with the digital telephone networks, which had a restricted bandwidth of approximately 3.5 kHz. In 1979 Johnston outlined a 7.5 kHz sub-band differential PCM (DPCM) that was suitable for speech and music signals. In the early 1980""s this work was developed using more sophisticated adaptive DPCM techniques (ADPCM), but it was not until 1988 that a true wideband high quality ADPCM coder was discussed.
In the mid-late 1980""s new methods for coding very high quality audio signals were developed based on high resolution filter-banks and/or transform coders, in which the quantizer bit-allocations were determined by a psychoacoustic masking model. In general, the psychoacoustic masking model tries to establish a quantization noise audibility threshold at all frequencies. The threshold is used to allocate quantization bits to reduce the likelihood that the quantization noise will become audible. The quantization noise threshold is calculated in the frequency domain from the absolute energy of the frequency-transformed audio signal. The dominant frequency components of the audio signal tend to mask the audibility of other components which are close in the bark scale (human auditory frequency scale) to the dominant signal.
Thus, the known high quality audio and music coders can be divided into two broad classes of schemes.
1) Medium to high frequency resolution subband/transform coders which adaptively quantize the subband or coefficient samples within the analysis window according to a psychoacoustic mask calculation.
These coders exploit the large short-term spectral variances of general music signals by allowing the bit-allocations to adapt according to the spectral energy of the signal. The high resolution of these coders allows the frequency transformed signal to be applied directly to the psychoacoustic model, which is based on a critical band theory of hearing. Dolby""s AC-3 audio coder, Todd et al., xe2x80x9cAC-3: Flexible Perceptual Coding for Audio Transmission and Storagexe2x80x9d Convention of the Audio Engineering Society, February, 1994, typically computes 1024-ffts on the respective PCM signals and applies a psychoacoustic model to the 1024 frequency coefficients in each channel to determine the bit rate for each coefficient. The Dolby system uses a transient analysis that reduces the window size to 256 samples to isolate the transients. The AC-3 coder uses a proprietary backward adaptation algorithm to decode the bit allocation. This reduces the amount of bit allocation information that is sent along side the encoded audio data. As a result, the bandwidth available to audio is increased over forward adaptive schemes which leads to an improvement in sound quality.
2) Low resolution subband coders which make-up for their poor frequency resolution by processing the subband samples using ADPCM. The quantization of the differential subband signals is either fixed or adapts to minimize the quantization noise power across all or some of the subbands, without any explicit reference to psychoacoustic masking theory. It is commonly accepted that a direct psychoacoustic distortion threshold cannot be applied to predictiv e/differential subband signals because of the difficulty in estimating the predictor performance ahead of the bit allocation process. The problems is further compounded by the interaction of quantization noise on the prediction process.
These coders work because perceptually critical audio signals are generally periodic over long periods of time. This periodicity is exploited by predictive differential quantization. Splitting the signal into a small number of sub-bands reduces the audible effects of noise modulation and allows the exploitation of long-term spectral variances in audio signals. If the number of subbands is increased, the prediction gain within each sub-band is reduced and at some point the prediction gain will tend to zero.
Digital Theater Systems, L. P. (DTS) makes use of an audio coder in which each PCM audio channel is filtered into four subbands and each subband is encoded using a backward ADPCM encoder that adapts the predictor coefficients to the sub-band data. The bit allocation is fixed and the same for each channel, with the lower frequency subbands being assigned more bits than the higher frequency subbands. The bit allocation provides a fixed compression ratio, for example, 4:1. The DTS coder is described by Mike Smyth and Stephen Smyth, xe2x80x9cAPT-X100: A LOW-DELAY, LOW BIT-RATE, SUB-BAN D ADPCM AUDIO CODER FOR BROADCASTING,xe2x80x9d Proceedings of the 10th International AES Conference 1991, pp. 41-56.
Both types of audio coders have other common limitations. First, known audio coders encode/decode with a fixed frame size, i.e. the number of samples or period of time represented by a frame is fixed. As a result, as the encoded transmission rate increases relative to the sampling rate, the amount of data (bytes) in the frame also increases. Thus, the decoder buffer size must be designed to accommodate the worst case scenario to avoid data overflow. This increases the amount of RAM, which is a primary cost component of the decoder. Secondly, the known audio coders are not easily expandable to sampling frequencies greater than 48 kHz. To do so would make the existing decoders incompatible with the format required for the new encoders. This lack of future compatibility is a serious limitation. Furthermore, the known formats used to encode the PCM data require that the entire frame be read in by the decoder before playback can be initiated. This requires that the buffer size be limited to approximately 100 ms blocks of data such that the delay or latency does not annoy the listener.
In addition, although these coders have encoding capability up to 24 kHz, often times the higher subbands are dropped. This reduces the high frequency fidelity or ambiance of the reconstructed signal. Known encoders typically employ one of two types of error detection schemes. The most common is Read Solomon coding, in which the encoder adds error detection bits to the side information in the data stream. This facilitates the detection and correction of any errors in the side information. However, errors in the audio data go undetected. Another approach is to check the frame and audio headers for invalid code states. For example, a particular 3-bit parameter may have only 3 valid states. If one of the other 5 states is identified then an error must have occurred. This only provides detection capability and does not detect errors in the audio data.
In view of the above problems, the present invention provides a multi-channel audio coder with the flexibility to accommodate a wide range of compression levels with better than CD quality at high bit rates and improved perceptual quality at low bit rates, with reduced playback latency, simplified error detection, improved pre-echo distortion, and future expandability to higher sampling rates.
This is accomplished with a subband coder that windows each audio channel into a sequence of audio frames, filters the frames into baseband and high frequency ranges, and decomposes each baseband signal into a plurality of subbands. The subband coder normally selects a non-perfect filter to decompose the baseband signal when the bit rate is low, but selects a perfect filter when the bit rate is sufficiently high. A high frequency coding stage encodes the high frequency signal independently of the baseband signal. A baseband coding stage includes a VQ and an ADPCM coder that encode the higher and lower frequency subbands, respectively. Each subband frame includes at least one subframe, each of which are further subdivided into a plurality of sub-subf rames. Each subframe is analyzed to estimate the prediction gain of the ADPCM coder, where the prediction capability is disabled when the prediction gain is low, and to detect transients to adjust the pre and post-transient SFs.
A global bit management (GBM) system allocates bits to each subframe by taking advantage of the differences between the multiple audio channels, the multiple subbands, and the subframes within the current frame. The GBM system initially allocates bits to each subframe by calculating its SMR modified by the prediction gain to satisfy a psychoacoustic model. The GBM system then allocates any remaining bits according to a MMSE approach to either immediately switch to a MMSE allocation, lower the overall noise floor, or gradually morph to a MMSE allocation.
A multiplexer generates output frames that include a sync word, a frame header, an audio header and at least one subframe, and which are multiplexed into a data stream at a transmission rate. The frame header includes the window size and the size of the current output frame. The audio header indicates a packing arrangement and a coding format for the audio frame. Each audio subframe includes side information for decoding the audio subframe without reference to any other subframe, high frequency VQ codes, a plurality of baseband audio sub-subframes, in which audio data for each channel""s lower frequency subbands is packed and multiplexed with the other channels, a high frequency audio block, in which audio data in the high frequency range for each channel is packed and multiplexed with the other channels so that the multi-channel audio signal is decodable at a plurality of decoding sampling rates, and an unpack sync for verifying the end of the subframe.
The window size is selected as a function of the ratio of the transmission rate to the encoder sampling rate so that the size of the output frame is constrained to lie in a desired range. When the amount of compression is relatively low the window size is reduced so that the frame size does not exceed an upper maximum. As a, result, a decoder can use an input buffer with a fixed and relatively small amount of RAM. When the amount of compression is relatively high, the window size is increased. As a result, the GBM system can distribute bits over a larger time window thereby improving encoder performance.
These and other features and advantages of the invention will be apparent to those skilled in the art from the following detailed description of preferred embodiments, taken together with the accompanying drawings and tables, in which:


The present disclosure relates to the field of display technologies and, in particular, to a display panel and a display device thereof, for reducing the border width of the display panel. The display panel includes: a display substrate including a display area and a stepped area disposed at a side of the display area, an integrated substrate is provided with an integrated circuit, and a flexible circuit board respectively connected with the stepped area of the display substrate and with the integrated substrate. The integrated circuit is electrically connected with the display substrate via a circuit on the flexible circuit board. The display panel is applicable in the display device.

With the development of display technology, the display device goes into the peoples' life, and the display device is developing to achieve a narrow border so as to realize full-screen display. That is, the non-display area outside the display area of the display panel is getting narrower and narrower.
Therefore, how to achieve a narrower border of the display device is a technical challenge in the current industry.

SHANGHAI TIANMA MICRO-ELECTRONICS CO., LTD.


A heat exchanger for a supercritical refrigerating cycle, comprising tubes 510 and tanks 520 which have plural hollow portions 520a and slots 521a for insertion of the ends of the tubes formed, wherein a sectional outline of the hollow portions of the tanks has an approximately semicircular shape with a side corresponding to the diameter directed to the side of the slots. And, the partition members each 523 is disposed between the plate bodies 521 and the tank member 522. The tanks are formed by assembling plate bodies 521 with slots formed and tank members 522 with plural curves formed to configure hollow portions, and the plate bodies are provided with communicating recesses 521b for communicating plural hollow portions. Besides, the partition members 523 for division of the hollow portions are disposed between the plate bodies and the tank members, holes 521c, 522a are formed in required portions of the plate bodies and the tank members, and plural projections 523a to be inserted through the individual holes are formed on the partition members and caulked after being inserted through the holes.

As a heat exchanger such as a radiator, an evaporator or the like used for the refrigerating cycle, one provided with tubes for flowing a refrigerant and tanks with slots formed for insertion of the tube ends is known. The refrigerant is taken from a tank into the interior, performs heat exchange with heat conducted to the tubes and is discharged outside from the tank.
As the refrigerant for the refrigerating cycle, a fluorocarbon refrigerant including hydrochlorofluorocarbon has been used extensively. But it is now being replaced with CO2 considering the global environment in these years.
A refrigerating cycle using CO2 as the refrigerant has a very high inside pressure as compared with the refrigerating cycle using a fluorocarbon refrigerant, and particularly a pressure on a high-pressure side happens to exceed the critical point of the refrigerant depending on use conditions such as a temperature.
The critical point is a limit on the high-pressure side (namely, a limit on a high-temperature side) in a state that a gas layer and a liquid layer coexist and an end at one end of a vapor pressure curve. A pressure, a temperature and a density at the critical point become a critical pressure, a critical temperature and a critical density, respectively. Especially, when the pressure exceeds the critical point of the refrigerant in a radiator which is a high-temperature heat source of the refrigerating cycle, the refrigerant does not condense.
A heat exchanger used for such a supercritical refrigerating cycle is described in, for example, Japanese Patent Laid-Open Publication No. HEI 11-351783.
As to the heat exchanger for the refrigerating cycle, improvement of heat exchange efficiency of the refrigerant, miniaturization, weight reduction, facilitation of production and saving of mounting space are significant objects. Especially, a supercritical refrigerating cycle having a pressure on the high-pressure side exceeding the critical point of the refrigerant requires a very high compressive strength as compared with the refrigerating cycle using the fluorocarbon refrigerant. And the heat exchanger used therefor is required to secure pressure resistance and to be rationalized furthermore.
For example, the heat exchanger for the supercritical refrigerating cycle needs to reduce volumes of the tubes and the tanks and to increase their wall thickness in order to secure the pressure resistance. Therefore, it becomes somewhat difficult to fabricate the members constituting them, and it is desired that the individual component members are fabricated more efficiently at a heat exchanger manufacturing site.
The present invention has been made in view of the above circumstances and provides a heat exchanger which is configured rationally in conformity with the above-described subject so to be used for the supercritical refrigerating cycle.


Provided herein are anti-fibrotic compounds, in particular those of Formula (I), that inhibit the TGF-beta signaling pathway. Also provided are pharmaceutical compositions comprising the anti-fibrotic compounds, and methods of treating diseases or conditions associated with fibrosis, inflammation, and benign or malignant neoplastic diseases in a subject by administering a compound or composition described herein. (Formula (I))

Tranilast (n-[3,4-dimethoxycinnamoyl] anthranilic acid) is an anti-fibrotic agent approved in Japan for the treatment of fibrotic skin disorders such as keloids and scleroderma. Although the precise mechanisms and mode of action are not completely understood, its ability to inhibit ERK phosphorylation, a major intermediate in the TGF-β signalling pathway, may underlie its antifibrotic effects, with known actions of tranilast including the inhibition of TGF-β-induced extracellular matrix production in a range of cell types. Tranilast has also been shown to attenuate TGF-β-induced collagen synthesis in cardiac fibroblasts using an experimental model of diabetic cardiac disease.
Fibrosis is a common response to a range of tissue insults that may lead to organ dysfunction. Diseases that are characterized by such pathological fibrosis include hepatic cirrhosis, pulmonary interstitial fibrosis, glomerulonephritis, heart failure (ischaemic and non-ischaemic), diabetic nephropathy, scleroderma, excessive scar tissue post surgery or device insertion, progressive kidney disease, glomerulonephritis, hypertension, heart failure due to ischaemic heart disease, valvular heart disease or hypertensive heart disease and hypertrophic scars. In addition, the elaboration of pathological matrix also has a role in fibroproliferative tumor progression and metastasis.
Diabetic subjects have a two- to five-fold increase risk of developing heart failure. In addition to ischaemic heart disease, heart failure in diabetes is also associated with a cardiomyopathy, independent of coronary artery disease. This so-called "diabetic cardiomyopathy" is characterised histologically by myocardial fibrosis with reduced myocardial elasticity, impaired contractility and overt cardiac dysfunction. Accordingly, strategies that reduce the pathological accumulation of extracellular matrix have been advocated as potential therapies for the treatment and prevention of heart failure in both diabetic and nondiabetic states.
Current treatment of chronic heart failure focuses on the modulation of the neurohormonal activation that typically develops in response to the evolving functional abnormalities. However, despite such therapy, frequently used in combination, cardiac dysfunction continues to progress in the majority of patients. Given the importance of pathological fibrosis in adverse cardiac remodelling, a potential role of antifibrotic agents has been suggested. Studies conducted over more than a decade have consistently indicated a major role for the prosclerotic growth factor, transforming growth factor-β (TGF-β) in organ fibrosis and dysfunction, such that blockade of its expression and action represent an important therapeutic target.
Tranilast has also been shown to reduce inflammation in allergic diseases, such as allergic rhinitis and bronchial asthma, etc., and have anti-proliferative activity.
However, it has recently been shown that genetic factors in certain patients, specifically a Gilbert's syndrome UGT1A1 variant, confers susceptibility to tranilast-induced hyperbilirubinemia. Such hyperbilirubinemia may be associated with tranilast itself or the formation, in vivo, of the following tranilast metabolite,

An ongoing need exists to identify and provide drugs with potential anti-fibrotic, anti-inflammatory, and anti-proliferative or anti-neoplastic activity for the treatment or prevention of diseases associated with fibrosis, diseases characterized by inflammation and neoplastic disease (both benign and malignant), and as alternatives/adjuncts to tranilast.


In a gasket sealing a gap between two opposed surfaces, the gasket is constructed by a tabular main body portion, two lip-like projections which are provided in one surface of the main body portion, and extend in parallel to each other along the main body portion, two small projections which are provided in the other surface of the main body portion and extend in parallel to each other along the main body portion, through holes which are provided at a plurality of positions of the main body portion, and an annular seal portion which is provided in such a manner as to surround the through holes. Accordingly, it is possible to have a good installation property of the gasket and a good stability (seating property) after the installation, and the gasket can be compressed highly by a low reaction force, and has a high reliability.

1. Field of the Invention
The present invention relates to a gasket.
More particularly, the present invention relates to a gasket which is useful by being used in a battery or the like which is used in an electric vehicle, a fuel cell vehicle, a hybrid vehicle and the like.
2. Description of the Conventional Art
Conventionally, as a gasket for sealing a gap between a case which is a base portion in a lower side of a battery case or the like, and a cover which is a lid portion in an upper side, there has been used an O-ring which has a circular cross section, or a gasket 100 which is obtained by drawing the O-ring in a vertical direction and has a cross sectional shape shown in FIG. 8 (refer to Japanese Unexamined Patent Publication No. 2005-16621).
However, the O-ring has such an advantage that it is simple in a shape so as to be easily produced, and an installing property and a stability after the installation (a seating property) is good, however, has such a disadvantage that a pressing crack tends to be caused at a high compressing time, and a high reaction force is generated.
Accordingly, there is brought about a problem that it can not be used at a position in which a gap greatly fluctuates, and a position in which a material of a case and a cover corresponding to the other end member to be attached is weak, and a width of the O-ring can not help but being larger in a compressed state (a set state) since it is used by compressing a circular cross section. Therefore, there is caused a problem that it can not be used in the case that an installation space is narrow, and a case that a high compression is necessary in comparison with an installation width.
Further, a gasket 100 having a cross sectional shape shown in FIG. 8 can expect an effect of lowering the pressing crack at a time of the high compression and the reaction force to some extent in comparison with the O-ring having a simple shape, however, not only it is impossible to achieve a low reaction force which can be sufficiently satisfied, but also it can not help but being used as a shape of being installed into a groove 210 which is provided in a case 200 as shown in FIG. 8 since a seating property is not good.
Further, it has been impossible to employ an aspect that a bolt hole for fixing the case and the cover is provided in the gasket 100 itself, for making the installation space narrow.


In an ignition timing control apparatus for an engine, a KCS learning value learned when the engine is in a given operating state is used in an ignition timing control executed when the engine is in the other operating state. An estimated knocking occurrence ignition timing is set based on a most retarded ignition timing using the KCS learning value. A final ignition timing is set by changing a KCS feedback correction value based on whether knocking occurs when ignition is performed at the estimated knocking occurrence ignition timing. When a point indicating the engine operating state moves into a region where it is difficult to set the estimated knocking occurrence ignition timing, the KCS feedback correction value is changed to retard the final ignition timing, and the final ignition timing is set using the KCS learning value and the changed KCS feedback correction value.

1. Field of the Invention
The invention relates to an ignition timing control apparatus and an ignition timing control method that control an ignition timing of an ignition plug according to an operating state of an internal combustion engine.
2. Description of the Related Art
In an internal combustion engine (hereinafter, may be simply referred to as "engine"), an ignition timing control is executed to generate an output most efficiently using combustion, and to provide good exhaust gas purification performance and good fuel efficiency. It is known to be preferable to make a pressure in a combustion chamber reach a peak slightly after a compression top dead center, to generate the output most efficiently using energy generated by the combustion. Therefore, an ignition timing is set so that the pressure reaches the peak slightly after the compression top dead center. However, when the ignition timing is too early (i.e., when the ignition timing is too advanced), knocking occurs.
An ignition timing control apparatus, which executes a knock control system (hereinafter, referred to as "KCS") control, is available. In the KCS control, it is determined whether knocking occurs using a knock sensor, and a feedback correction process (feedback control) is executed to adjust the ignition timing, according to the determination as to whether knocking occurs. Also, to execute the feedback correction process in quick response to the determination, a learning control is executed to store and retain, as a learning value, the degree of change in the ignition timing caused by the feedback correction process (for example, refer to Japanese Patent Application Publication No. 2002-031024 (JP-A-2002-031024) and Japanese Patent Application Publication No. 2005-147112 (JP-A-2005-147112)). The ignition timing control apparatus calculates a final ignition timing in the engine, for example, based on the equation (3) and the equation (4) described later (refer to, for example, FIG. 4).
In the ignition timing control apparatus described in Japanese Patent Application Publication No. 2002-031024 (JP-A-2002-031024), the learning value (KCS teaming value), which is learned by the earning control when the engine E is in a given operating state, is used in the ignition timing control executed when the engine E is in the other operating state. For example, a line indicating the ignition timing (estimated knocking occurrence ignition timing) is set to be parallel to a line for setting a most retarded ignition timing, and ignition is performed at the ignition timing on the line indicating the estimated knocking occurrence ignition timing. The estimated knocking occurrence ignition timing is the estimated most advanced ignition timing at which occurrence of knocking is suppressed. In this case, the line indicating the estimated knocking occurrence ignition timing is parallel to, and advanced with respect to the line indicating the most retarded ignition timing by the learning value that is used. Then, the final ignition timing is set based on the ignition timing feedback-corrected according to whether knocking occurs (refer to, for example, FIG. 4). As a result, the ignition timing when the engine is in the operating state is learned, and the learning value is updated. The learning value, which is learned in the above-described manner, is further used in the ignition timing control executed when the engine is in the other operating state.
In the above-described ignition timing control apparatus, to suppress occurrence of knocking, it is important to accurately set the estimated knocking occurrence ignition timing based on the most retarded ignition timing using the learning value learned by the learning control. That is, if the estimated knocking occurrence ignition timing cannot be accurately set, much time is required to stop knocking. Therefore, knocking may continue to occur a plurality of times. Also, knocking noise may be transmitted to a vehicle cabin, and an occupant may feel discomfort. Further the engine may be adversely influenced.
However, it is difficult to accurately set the estimated knocking occurrence ignition timing in individual engines, because there are various driving environments, and there are variations among individual engines. In addition, it may be difficult to accurately set the estimated knocking occurrence ignition timing, depending on an operating condition of the engine.
In such a case, if the learning value learned by the above-described learning control is used without correction, the estimated knocking occurrence ignition timing may greatly vary. Accordingly, when the engine is operated in a certain operating condition, it is not appropriate to use the learning value learned by the above-described learning control without correction.
For example, when a driver operates an accelerator pedal, and therefore, a point indicating the operating state of the engine moves into a low load region, it is not appropriate to use the learning value without correction. When the point indicating the operating state of the engine is in the low load region, the ignition timing is sensitive to the driving environment, the variations among the individual engines, and the like, and therefore the ignition timing is likely to fluctuate. Thus, it is difficult to accurately set the estimated knocking occurrence ignition timing.
Also, for example, when deposits are formed in the engine due to unburned fuel, blow-by gas, lubricant oil, and the like, and the degree of formation of deposits is high, it is not appropriate, to use the learning value without correction. As the engine is used, deposits are gradually formed in an intake port, an intake valve, a piston, and the like. When the degree of formation of deposits is increased, the substantive volume of a combustion chamber is decreased, and therefore, a cylinder pressure at the time of combustion is increased. As a result, knocking is likely to occur. In the publication No. 2005-147112, it is described that a ratio learning process is executed taking into account the influence of formation of deposits in the ignition timing control. However, as the load of the engine becomes lower, the influence of deposits is more notable. Therefore, when the point indicating the operating state of the engine is in the low load region, even if the ratio learning process is executed, it is difficult to accurately set the estimated knocking occurrence ignition timing.
Also, as described above, when the estimated knocking occurrence ignition timing cannot be accurately set a determination as to whether knocking occurs (hereinafter, referred to as "knocking determination") may be adversely influenced. That is, when knocking gradually occurs, it can be accurately determined that knocking occurs. However, because the estimated knocking occurrence ignition timing cannot be accurately set, if the operating state of the engine suddenly changes, and unexpected knocking at a high level (extremely high-level knocking) occurs, it may not be possible to accurately determine that knocking occurs.
The knocking determination may be performed by comparing a peak hold value of an output from a knock sensor (shown by the chain line in FIG. 11) with a background signal and that is assumed to be a normally-distributed signal (shown by the dashed line in FIG. 11). In this case, when the level of the output from the knock sensor is equal to or above a knocking determination level (Th1 it FIG. 11), and a difference between the output from the knock sensor and the background signal is equal to or above a predetermined determination value, it is determined that knocking occurs. However, in this case, when the level of the background signal increases, for example, due to occurrence of unexpected extremely high-level knocking (as shown by the solid line in FIG. 11), the knocking determination level also increases to a higher level (Th2 in FIG. 11). When the knocking determination level increases, it may be determined that knocking does not occur even if knocking actually occurs. As a result, it is not possible to appropriately retard the ignition timing, and knocking may continue to occur.

Ignition timing control apparatus and ignition timing control method for internal combustion engine


A current/voltage control apparatus for an elevator system which is capable of preventing an over current from being applied to an inverter by stopping a driving operation of the inverter when a difference (hereinafter called "current deviation") between a current instruction and actual current value exceed a predetermined value during a predetermined time. The apparatus includes a voltage limiter for setting a limit voltage value which is proportional to an operational frequency of the induction motor and applying the voltage below the limit voltage value to the inverter driving unit, a zero phase component current detector for detecting a zero phase component current and outputting an inverter driving stop signal to the inverter driving unit when the thusly detected current exceeds a predetermined reference value, and a current deviation detector for detecting a current deviation value and outputting an inverter driving stop signal to the inverter driving unit when the current deviation value, which exceeds a predetermined reference value, is continuously maintained for a predetermined time.

1. Field of the Invention
The present invention relates to a current/voltage control apparatus for an elevator system, and in particular to an improved current/voltage control apparatus for an elevator system which is capable of preventing an over-current and over-voltage from being transferred to an inverter.
2. Description of the Background Art
As the technology of a high-power semiconductor device is advanced, the motor type for the elevator system is changed from the direct current motor to the induction motor. For controlling the induction motor, recently a vector control method is increasingly used based on a VVVF (Variable Voltage Variable Frequency). In particular, the input current of the induction motor is separated into a magnetic component current and a torque component current for vector-controlling the induction motor, so that an instantaneous torque control of the induction motor is made possible.
In order to VVVF-control the induction motor, there are provided a converter for converting a three-phase alternating current voltage into a direct current voltage and an inverter for converting the direct current voltage into an alternating current voltage of a variable voltage type and variable frequency type. The instantaneous torque control of the induction motor is implemented by controlling the switching operation of the inverter. Therefore, the current/voltage control apparatus is designed to prevent an abnormal operation of the inverter.
FIG. 1 illustrates the inner construction of the conventional current/voltage control apparatus for an elevator system.
As shown therein, the conventional elevator system includes a converter 1 for converting a three-phase alternating current voltage AC into a direct current voltage by rectifying the same, an inverter 2 for converting the thusly converted direct current voltage into an alternating current voltage of a variable voltage and frequency type, an induction motor 4 for generating force for running an elevator car 8 using the thusly converted alternating current voltage, current sensors 3A through 3C for sensing three-phase current flowing in the induction motor 4, a sheave 5, rope 6 and balance weight 7 for receiving a force from the induction motor 4 and running the elevator car 8 along a running path formed through each floor, a velocity detector 9 for detecting an actual rotational frequency .omega..sub.r of the induction motor 4, an over current detector 10 for comparing the current of each phase sensed by the current sensors 3A through 3C with a previously set limit current value and generating a driving stop signal of the inverter 2 when the current thereof exceeds the limit current value as a result of the comparison, current amplifiers 11A through 11C for amplifying the current of each phase sensed by the current sensors 3A through 3C to a predetermined level, respectively, a current transformer 12 for the three phase currents (i.sub.a, i.sub.b, i.sub.c) from the current amplifiers 11A through 11C into a torque component (Q-axis) current (i.sub.q), a magnetic component (D-axis) current (i.sub.d), a velocity instruction generator 13 for generating a velocity instruction (W*) corresponding to the operational instruction (D*), a subtractor 14 for computing a difference of an actual rotational frequency (.omega..sub.r) between the velocity instruction (W*) and the induction motor 4, a velocity controller 15 for generating a torque component current instruction (i.sub.q *) which is proportional to the above difference, a magnetic component current instruction generator 16 for generating a magnetic component current instruction (i.sub.d *) corresponding to the operational instruction (D*) , a subtractor 17 for computing a difference with respect to the torque component current (i.sub.q) from the current transformer 12, a subtractor 18 for computing a difference between the magnetic flux component current instruction (i.sub.d *) outputted from the magnetic flux component current instruction generator 16 and the magnetic flux component current (i.sub.d) outputted from the current transformer 12, Q-axis and D-axis current controllers 19A and 19B for generating Q-axis and D-axis voltage instructions (V.sub.q, V.sub.d) for controlling the Q-axis current and d-axis current from the induction motor 4 based on the output currents from the subtractors 17 and 18, a slip computation unit 20 for computing a slip frequency .omega..sub.s of the induction motor 4 based on the torque component current instruction (i.sub.q *) , an adder 21 for adding the rotational frequency .omega..sub.r detected by the velocity detector 9 and the slip frequency .omega..sub.s computed by the slip computation unit 20 and outputting an operational frequency .omega..sub.e of the induction motor 4, a voltage transformer 22 for converting the operational frequency .omega..sub.e and the Q-axis and D-axis voltage instructions V.sub.q, V.sub.d into three phase voltage instructions V.sub.a, V.sub.b, V.sub.c, a voltage limiter 23 for limiting the output ranges of the three phase voltage instructions V.sub.a, V.sub.b, V.sub.c, and an inverter driving unit 24 for generating a pulse modulation signal corresponding to the inverter driving control signal from the voltage limiter 23 or the over current detector 10 and driving the inverter 2.
The operation of the conventional elevator system will now be explained with reference to FIGS. 1 through 4.
First, when a three phase alternating current (AC) voltage is inputted, the three phase alternating current voltage is converted into a direct current voltage by the converter 1 and is smoothed by a condenser C and is supplied to the inverter 2. The inverter 2 converts the thusly inputted direct current voltage into an alternating current voltage of a variable voltage type and variable frequency type and then is supplied to the induction motor 4.
In addition, when the velocity detector 9 detects an actual rotational frequency .omega..sub.r of the induction motor 4, and the velocity instruction generator 12 generates a velocity instruction W* corresponding to the operational instruction D*, the subtractor 14 computes a difference between the velocity instruction W* and the rotational frequency .omega..sub.r. The velocity controller generates a torque component current instruction (i.sub.q *) which is proportional to the difference, and the magnetic flux component current instruction generator 16 generates a magnetic flux component current instruction (i.sub.d *) in accordance with the operational instruction D*.
FIGS. 2A through 2C are wave form diagrams of the velocity instruction W*, the torque component current instruction (i.sub.q *) and the magnetic flux component current instruction (i.sub.d *).
When the velocity instruction W*, as shown in FIG. 2A, is generated by the velocity instruction generator 13, the velocity controller 15 generates the torque component current instruction (i.sub.q *), as shown in FIG. 2B, which is proportional to the difference between the velocity instruction W* and the rotational frequency .omega..sub.r. The magnetic flux component current instruction generator 16 generates the current instruction (i.sub.d *) having a predetermined size, as shown in FIG. 2C, while the operational instruction D* is in the RUN state.
In addition, the three phase current flowing in the induction motor 4 is detected by the current sensors 3A through 3C, and the thusly detected three phase current is amplified to a predetermined level by the current amplifiers 11A through 11C.
At this time, the over current detector 10 compares the current value detected by the current sensors 3A through 3C with the set limit current value I.sub.-- limit. As a result of the comparison, if the three phase current value exceeds the same, the inverter driving stop signal is generated.
FIGS. 3A and 3B illustrate wave form diagrams for explaining an operational timing of the over current detector 10.
At the point P where the current value detected by the current sensors 3A through 3C exceeds a limit current value I.sub.-- limit as shown in FIG. 3A, the over current detector 10 generates an inverter driving stop signal as shown in FIG. 3B.
In addition, the three phase currents i.sub.a, i.sub.b, and i.sub.c, amplified by the current amplifiers 11A through 11C are converted into the Q-axis and D-axis currents i.sub.q, i.sub.d by the current transformer 12 based on the Equations 1 through 3. EQU i.sub.a =Icos (.omega..sub.e -.theta.) EQU i.sub.b =Icos (.omega..sub.e -2.pi./3-.theta.) EQU i.sub.c =Icos (.omega..sub.e -2.pi./3+.theta.) . . . Equation 1 EQU i.sub..alpha. =(i.sub.c -i.sub.b).sqroot.3=-Isin (.omega..sub.e -.theta.) EQU i.sub..beta. =i.sub.a =Icos (.omega..sub.e -.theta.) . . . Equation 2 EQU i.sub.d =cos (.omega..sub.e t).times.i.sub..alpha. +sin (.omega..sub.e t).times.i.sub..beta. =Isin (.theta.) EQU i.sub.q =-sin (.omega..sub.e t).times.i.sub..alpha. +cos (.omega..sub.e t).times.i.sub..beta. =Icos (.theta.) . . . Equation 3
where .omega..sub.e denotes the operational frequency, and .theta. denotes the phase angle.
As seen in Equation 3, the Q-axis and D-axis currents i.sub.q and i.sub.d are inputted into the subtractors 17 and 18, respectively, and are compared with the torque component current instruction (i.sub.q *) and the magnetic flux component current instruction (i.sub.d *) outputted from the velocity controller 15 and the magnetic flux component current instruction generator 16. When a difference value corresponding to the comparison is outputted, the Q-axis current controller 19A and D-axis current controller 19B generate the Q-axis and D-axis voltage instructions V.sub.q and V.sub.d.
In addition, when the slip computation unit 20 outputs a slip frequency .omega..sub.s which is proportional to the torque component current instruction (i.sub.q *) outputted from the velocity controller 15, the adder 21 adds the slip frequency .omega..sub.s and the rotational frequency .omega..sub.r of the induction motor 4, thus outputting an operational frequency .omega..sub.e.
In addition, the voltage transformer 22 outputs the three phase voltage instructions V.sub.a, V.sub.b, and V.sub.c based on the following Equations 4 and 5 using the operational frequency .omega..sub.e outputted from the adder 21 and the Q-axis and d-axis voltage instructions V.sub.q and V.sub.d generated by the Q-axis and D-axis current controllers 19A and 19B. EQU V.sub..alpha. =-V.sub.q .times.sin (.omega..sub.e t)+V.sub.d .times.cos (.omega..sub.e t) EQU V.sub..beta. =+V.sub.q .times.cos (.omega..sub.e t)+V.sub.d .times.sin (.omega..sub.e t) . . . Equation 4 EQU V.sub.a =V.sub..beta. ##EQU1##
The thusly computed three phase voltage instructions V.sub.a, V.sub.b and V.sub.c are inputted into the voltage limiter 23 and compared with the limit voltage value V.sub.-- limit. Only the voltage is below the limit voltage value V-limit is applied to the inverter driving unit 24, so that the over voltage is not applied to the inverter 2 and the induction motor 4.
FIGS. 4A and 4B illustrate the wave form diagrams of voltage signals applied to the induction motor 4.
When the velocity instruction W*, as shown in FIG. 4A, occurs, the applying voltage of the induction motor 4 which is proportional to the thusly occurring velocity instruction W* is outputted as shown in FIG. 4B. Here, V-rate denotes a rated voltage, and V-limit denotes a limit voltage value.
As shown in FIG. 4B, the applying voltage which is limited below the limit voltage value V.sub.-- limit is inputted into the inverter driving unit 24, and the inverter driving unit 24 outputs a pulse-modulated signal to the inverter 2 when the operational instruction D* is in a RUN state, namely, it is activated, thus switching and internal power transistor, so that it is possible to control the velocity and current of the induction motor.
In addition, the rotational force of the induction motor 4 is transferred to the car 8 through the sheave 5 and rope 6, so that the car 8 is moved to a destination floor along the running path.
In the conventional current/voltage control apparatus for an elevator system, the over current detector 12 and the voltage limiter 23 are provided for preventing an over current and voltage from being transferred to the inverter 2.
As shown in FIG. 4, the limit voltage value V.sub.-- limit of the voltage limiter 23 always maintains a constant value. However, the applying voltage applied to the induction motor 4 is always proportional to the velocity of the induction motor 4.
Therefore, when the induction motor 4 operates at a low velocity, the Q-axis and D-axis currents are controlled by a voltage which is lower than the rated voltage V.sub.-- rate, so that it is impossible to obtain a desired prevention operation with respect to the system.
In addition, if the three phase parameters of the induction motor 4 are parallel, the three phase currents flowing in the induction motor 4 become parallel based on Equation 1, so that the sum of the three phase currents, namely, the zero phase component current becomes 0. If the three phase parameters are not parallel due to a predetermined factor, since the three phase currents flowing in the induction motor 4 are not parallel, the sum of the three currents does not become zero.
In this case, the current flowing in the induction motor 4 may become smaller than the limit current value I.sub.-- limit of the over current detector 10, or may become larger than the rated current of the induction motor 4. since the conventional over current detector 10 is not capable of detecting the above-described problem, the elevator system is continuously operated irrespective of the above-described problems, so that more serious problem may occur.
In addition, in the current control circuit if the current value is not detected due to a failure of the current sensors 3A through 3C, or the short circuit of the sensor output cable, a large voltage instruction occurs in the Q-axis and D-axis current controllers 19A and 19B during a low velocity operation. Therefore, an over current flows in the inverter and induction motor. When this over current is not detected, the inverter and motor may be damaged.

Current/voltage control apparatus for elevator system


A method for administering pyruvate is disclosed which comprises administering a therapeutically effective amount of a pyruvate precursor to a mammal in the form of pyruvamide or a pyruvyl-amino acid. The pyruvyl-amino acid is preferably selected from the group comprising pyruvyl-glycine, pyruvyl-alanine, pyruvyl-leucine, pyruvyl-valine, pyruvyl-isoleucine, pyruvyl-phenylalanine, pyruvyl-proline and pyruvyl-sarcosine, and their amides and esters as well as their salts. Associated with the administration of a pyruvate precursor to a mammal in accordance with this invention are improved insulin resistance, lower fasting insulin levels, and reduced fat gain. Novel methods of synthesizing several pyruvate precursors are also disclosed.

Obesity is a multifactorial disease which affects upwards of 25% of the adult population in the United States of America. It is estimated that in the U.S.A. between 34-50 million adults are obese, with at least 5 million of those adults receiving medical treatment for their obesity. The etiology of obesity can range from simple overeating to severe hormonal imbalance. However, the great majority of obesity is probably due to a complex relationship between the many factors that regulate energy intake and utilization.
Teleologically, obese individuals may be better prepared for survival in time of limited food supply because of their ability to utilize energy in a more efficient manner. However, given that there is almost an unlimited food supply in the U.S.A., this efficiency of energy utilization probably leads to obesity. Furthermore, obesity is associated with an increased risk of cardiovascular disease, an increased risk of Type II diabetes, an increased risk of coronary artery disease, and other chronic diseases. For example, it is believed that in the U.S.A. there are over 6 million diagnosed cases of obese Type II diabetes, with an estimated 4 million cases being undiagnosed.
Given the large obese population and the associated problems, the area of obesity research and product development for the management of obesity has been explored, yet the problem remains. U.S. Pat. No. 4,351,835 teaches a method for preventing body fat deposition in mammals by oral administration of a mixture of pyruvate and dihydroxyacetone (DHA).
Subsequent additional research with rats investigated the effect of pyruvate and DHA under normal dietary conditions. In that study, rats were fed either a controlled diet or an experimental diet in which part of the carbohydrates were replaced with a 1:1 mixture of pyruvate and DHA, which mixture constituted 15% of the total caloric intake. Rats which received the experimental diet gained less weight, and had greater rates of heat production and energy expenditure than rats receiving a control diet. The experimental diet reduced body fat content by 32% without any significant effect on either protein or water content.
Similarly, in another study, Type II diabetic humans were fed 56 grams of pyruvate and OHA in a 1:1 mixture for seven days, during which time period glucose tolerance and turnover were measured. Reductions in fasting blood glucose concentration and peak glucose concentration after a glucose tolerance test were observed.
Yet another study assessed the relative effectiveness of pyruvate and DHA. In that study, obese Zucker rats were placed in one of four diet groups. One diet was a control and each of the other diets featured a semi-purified rat diet with only one of the following features: (a) 6% pyruvate, (b) 6% DHA, or (c) 6% pyruvate/DHA (1:1). A number of physiologic variables were measured. The conclusion of the study was that generally changes due to the addition of DHA or pyruvate/DHA to the diet were not as great as changes due to the addition of only pyruvate. In fact, often the changes due to the addition of DHA or pyruvate/DHA could either be attributed to feed restriction or to the pyruvate in combination.
Finally, U.S. Pat. No. 4,548,937 discloses a method for minimizing weight gain by adding pyruvate to the diet.
Based on the above studies, the experimental data indicated that pyruvate was an efficacious compound in altering metabolic variables in rats. Pyruvate, also known as pyruvic acid, is a common metabolite of the body.
A problem exists in administering effective dosages of pyruvate to humans in that heretofore the only ways to supply pyruvate have been in the form of a liquified pyruvic acid or in the form of the mineral salts of pyruvate, for example via sodium, potassium or calcium salts. These salts are organoleptically poor, as is tolerance of these salts. Furthermore, in humans the amount of these salts required to obtain the proper dosage of pyruvate for maximal effect raises the electrolyte level of the recipient to 2-6 times the safe and adequate recommended level when given as a supplement to a typical diet. With respect to the liquid pyruvic acid, the liquid is very acidic and results in the body literally being burned. Attempting to solve the acidity problem through dilution results in the human body being unable to ingest acceptable levels of pyruvate.
It is thus apparent that the need exists for an improved method of administering pyruvate to humans. It is also apparent that the need exists for an improved method of synthesizing a hydrolyzable precursor for pyruvate, other than in the form of a pyruvate salt.

Method of synthesizing the precursor pyruvamide


Modified oligonucleotides 3'-NHP(O)(O.sup.-)O-5' phosphoramidates were synthesized on a solid phase support. The phosphoramidate analogs were found to have significantly increased resistance toward phosphodiesterase digestion. Thermal dissociation experiments demonstrated that these compounds form more stable duplexes than phosphodiesters with complementary DNA and particularly RNA strands. Further, the phosphoramidate analogs can also form stable triplexes with double-stranded DNA target, where under similar conditions parent phosphodiester compounds failed to do so.

Oligonucleotides have been proposed as potent diagnostic compounds and as new rationally designed therapeutic agents (Uhlman, 1990; Helene, et al., 1990; Helene, 1991). The mechanism of action of these compounds is based on their specific interaction with RNA or DNA regions of interest.
Several modifications of the natural phosphodiester internucleoside bond {phosphomono- (Eckstein, et al., 1985; Cohen, 1993) or dithioate (Marshall, et al., 1993), methylphosphonate (Miller, 1991), phosphodiester amidate (Letsinger, et al., 1988; Froehler, et al., 1988)} have been introduced to improve (i) the stability of the oligomers in biological media, and (ii) the hybridization properties of the oligomers.
Unfortunately, the vast majority of these analogs exhibit reduced binding with target RNA or DNA strands via duplex or triplex formation (Kibler-Herzog, et al., 1991). Moreover, the presence of the stereoisomers at phosphorous in some of these analogs may complicate the binding patterns with complimentary nucleic acids (LaPlauche, et al., 1986; Bower, et al., 1987; Tidd, et al., 1988).


Contactor switches between a multi-cell battery pack and an electric vehicle load are monitored. A main microcontroller having a chassis ground is digitally isolated from positive and negative busses of the battery pack. A battery monitoring IC having a plurality of auxiliary/thermistor A/D inputs measures respective voltages of battery cells. An evaluation switch is connected to a junction between a first contactor switch and the load. The evaluation switch is activated in response to a command received from the main microprocessor. A voltage divider is coupled between the output of the evaluation switch and the negative bus to provide a divided voltage output to one of the auxiliary/thermistor A/D inputs. The battery monitoring IC transmits a digital value representative of the divided voltage output to the main microprocessor via a serial data link, and the main microprocessor determines a state of the contactor in response to the digital value.

The present invention relates in general to vehicles with electric propulsion, and, more specifically, to monitoring of battery contactor switches by a microcontroller that is digitally isolated from the battery circuits.
The DC power source (e.g., a battery) and other elements of electric drives for hybrid or electric vehicles require monitoring in order to maximize efficiency and performance as well as to detect potential malfunctions. Common battery types such as lithium ion (Li-Ion) use a large number of cells stacked together into a battery pack. Besides monitoring the total voltage output by a battery pack, each cell is typically monitored individually to determine their voltage production and other parameters. The temperature of each cell is also monitored in order to protect against overheating.
It is very challenging to reliably monitor the various battery conditions because of the high-voltage levels involved, the range of intermediate voltages at which respective cells operate within the stack, and the high levels of accuracy required. Various battery monitoring integrated circuit devices have been developed commercially for use in the vehicle environment. Examples of a commercially available battery monitoring IC device include the AD7280A device available from Analog Devices, Inc., of Norwood, Mass., the LTC6804 devices available from Linear Technology Corporation of Milpitas, Calif., and the ISL94212 Multi-Cell Li-Ion Battery Manager available from Intersil Corporation of Milpitas, Calif. In addition to a plurality of inputs for directly monitoring respective battery cells, the known IC devices include several analog inputs for measuring the outputs of thermistor circuits used as temperature sensors for the respective battery cells.
The measured parameters of the battery cells, battery pack, and associated devices are all used by a main microcontroller or microprocessor for performing battery management and communication. Some of the primary components to be monitored include the battery contactor switches that couple the battery pack to the vehicle loads (e.g., the inverter for driving an electric motor). The main micro is typically located in a discrete battery control module or box that interfaces with other vehicle components such as a vehicle system/powertrain controller or a driver interface module. Consequently, the main micro uses a chassis ground for its voltage reference. The chassis ground is isolated from the main battery's reference which is provided at a negative battery bus.
The battery monitoring ICs deployed with the battery pack must monitor the battery cells while being referenced to the negative bus. Therefore, the battery monitoring ICs and any other monitoring devices connected in the high-voltage domain must communicate with the main micro through domain-crossing elements that provide digital isolation between the high-voltage battery domain and the chassis ground domain (i.e., low voltage domain) of the main micro. In order for the main micro to both control the monitoring elements and receive the resulting measured data, relatively expensive components such as photoMOS transistors and a dedicated, high-voltage-referenced analog-to-digital (A/D) converter integrated circuit are typically employed. It would be very desirable to avoid the use of the expensive add-on components while maintaining robust detection of the state of the contactor switches.

This patent is subject to a terminal disclaimer.

Electric vehicle battery contactor switch monitoring


Disclosed is a radiation image conversion panel containing a support having thereon a phosphor layer containing an alkali metal halide phosphor which is deposited on the support by a gas phase accumulation method, wherein the alkali metal halide phosphor includes a columnar crystal and an existing ratio of an activation agent of the columnar crystal on a surface of the columnar crystal to an inner portion of the columnar crystal is from 0.7 to 20.

A conventional radiation image conversion panel containing a stimulable phosphor layer prepared by a gas phase accumulation method has a columnar crystal in the phosphor layer. Since this type of radiation image conversion panel contains no binder resin, there are formed spaces between one columnar crystal and other columnar crystals. Therefore, diffusion of an excitation light can be prevented and improvement of a taking out efficiency of an emitting light can be achieved, which results in obtaining an image of high luminance and high sharpness.
However, this radiation image conversion panel has a problem of easily deteriorating during storage because it contains no binder, and as a result, the surface of the phosphor is exposed. It was needed to figure out a way such as surface treatment and lamination to avoid contact with the outside air as much as possible.
Even though the performance degradation as a product can be prevented, unlike the inner portion of a crystal, the surface and the side of the phosphor crystal basically prepared by a gas phase accumulation method are placed under various environmental conditions in the processes from vapor deposition to sealing.
For example, during the vapor deposition process, there are factors such as vacuum atmosphere, change of a temperature and adsorption and desorption of an inert gas. And during the subsequent processes, there are factors caused by a surface treatment and influences of water in the atmosphere. Thereby, there was a problem that a content of an activating agent tends to be different between the surface and the inner portion of the crystal.
Moreover, about the surface state of the phosphor crystal, which seems to have an important role on performance of the phosphor, there have been disclosed very limited reports until now. There was disclosed only a report in which a ratio of Cs and C was specified (for example, refer to Patent Document 1). The purpose of this disclosure is to decrease contamination on the crystal surface and this differs from the present invention in that it is not an investigation of a distribution of an activating agent concentration.
Patent Document 1: JP-A 2005-24272


An axle driving system which houses in a housing thereof a hydrostatic transmission, axles, and a driving gear train for connecting output means of the hydraulic transmission and axles, so as to transmit power from a driving source to the hydrostatic transmission and to change the speed, thereby driving the axles. A first chamber therein contains the hydrostatic transmission and a second chamber therein contains the driving gear train. Both the first and second chambers are independent of each other so as to prevent a foreign object, such as iron powder produced in the driving gear train, from entering the hydrostatic transmission. The system includes an L-like-shaped center section on which the hydrostatic transmission is offset such that an imaginary plane which includes a motor mounting surface passes in proximity to the axis of a pump shaft. The pump shaft is disposed perpendicular to the axles. The motor shaft is disposed in parallel thereto. A hydraulic pump is positioned between the hydraulic motor and the axles, so that the housing for the hydrostatic transmission, axles and driving gear train, is smaller in width to thereby make the system more compact.

1. Field of the Invention
The present invention relates to an axle driving system in which a hydrostatic transmission (hereinafter referred to as an "HST"), axles and a power transmitting mechanism are integrally provided in a housing, and more particularly to an axle driving system in which the width of the portion of the housing which houses the HST and power transmitting mechanism is smaller than in conventional systems.
2. Background Art
A conventional axle driving system houses the HST, axles and a driving gear train for interlocking the HST with the axles in a common housing. The HST is constructed so that a hydraulic pump is disposed on a horizontal portion of a center section which is L-like-shaped and a hydraulic—motor is disposed on the vertical portion of the same. The hydraulic motor is positioned to one side of the axle. The hydraulic pump and hydraulic motor are fluidly connected to each other by a closed fluid circuit formed in the center section. The hydraulic pump is driven by a prime mover provided on the vehicle so as to drive the hydraulic motor and then the axles through a driving gear train. Such a construction is disclosed, for example, in U.S. Pat. Nos. 5,163,293 and 5,335,496.
The hydraulic pump and hydraulic motor in the conventional technique, are disposed side-by-side and to one side of the axles. As such, the width of the HST is larger which results in the lateral width of the common housing for both the pump and motor also being larger. Furthermore, an output shaft of the hydraulic motor extends to one side of the vehicle to transmit power therefrom to a differential gear unit through gears of a driving gear train, so as to drive the axles. An unused space is formed at a side of the gear train and between the HST pump and the axles.
Further, when the HST and the driving gear train for driving the axles by the output shaft of the HST are housed in a common housing, a foreign object, such as iron powder produced by the driving gear train, may enter into the HST. This can adversely affect operation of the HST or various parts thereof.


A network device includes network ports to communicate with source devices and destination devices. The network device receives respective packets from each source device and, for each source device, respectively performs the following operations. The network device stores the respective packets in a shared memory that stores all packets from all of the source devices, and dequeues the respective packets from the shared memory to send the packets to destination devices. Responsive to the storing and the dequeuing, the network device respectively increases and decreases an input packet count for the source device. The network device determines for the source device a packet sending rate based on the input packet count and a flow control threshold common across all of the source devices in accordance with a proportional integral (PI) control equation. The network device transmits to the source device a control message including the packet sending rate.

Remote direct memory access (RDMA) deployment in modern data centers requires reliability over Layer (L) 2 links. Mechanisms such as Institute of Electrical and Electronics Engineers (IEEE) 802.3x Pause or IEEE 802.1Qbb Priority Flow Control (PFC) can be used to achieve a lossless network. During packet transfers from senders to an Ethernet switch, the switch can send to all or some of the senders Pause or PFC control frames when the switch is running out of buffer space for incoming packets. Upon receiving such control messages, the senders stop sending packets, therefore preventing packet drop at the switch/receiver. In the case of a shared buffer at the switch, the switch stops all of the senders if a total packet occupancy of the buffer is reaching the maximum buffer available. This is undesirable because only one sender may fill the whole buffer at the switch, but all senders are paused even though they are not all sending packets to a congested port causing the buffer to fill. This presents a problem of how to share the buffer across all input ports efficiently such that each input port gets a fair share of the total buffer and total buffer usage remains under the total buffer available. Another problem is head of line blocking (HOLB). If an input source is shared by two flows, one sending packets to a congested port and one sending packets to a non-congested port, the latter flow (i.e., the victim flow) should not be affected by the former flow.

Proportional integral based shaper for lossless output buffer


An item with a surface area creating an optical effect is such that the surface area with the optical effect exhibits at least two images (12, 14) separated a distance (d) from each other by means of a transparent layer of material (10). The distance (d) between the images 12, 14) and the distance (a) between two neighboring elements (16) forming the images (12, 14) are adjusted with respect to each other such that on altering the viewing angle (xcex1) the perceived overall image formed by the overlapping of the images (12, 14) is altered. A preferred application for the item lies in forms of packaging, packaging material, an aid to packaging, bonds or entry tickets with forgery-proof surface area and/or surface areas that have to meet high demands.

1. Field of the Invention
The invention relates to an item with a surface area exhibiting an optical effect. Also within the scope of the invention is a process for manufacturing the item and the use thereof.
2. Background Invention
Proof against forgery in packaging is of great importance especially for the pharmaceutical industry. Basically, however, in other branches of industry there is a wish for forgery-proof packaging or products, in particular in the consumer industry, e.g., the packaging of foodstuffs, cosmetic items, clothes, software and music CDs or bonds. The item with the surface area exhibiting the optical effect may be packaging, packaging material, an aid to packaging or a product itself on which a surface area is provided with a security part, e.g., in the form of a label bearing an optical effect.
Forgery-proof packaging or packaging material may serve as guarantee of origin, enabling the customer to recognize that the purchased item was actually manufactured and packaged by the desired manufacturer. Forgery-proof packaging material may also be used as guarantee of first opening, e.g., in the form of a label, band or sealing strip, etc., which has, e.g., been affixed to the goods over a bottle closure or over a closure on a wide-necked glass, across a seam between a lid and a container or over the tear-off closure on a pouch. On opening the packaging in question the label, band or sealing strip is broken, demonstrating that the package has already been opened. It is also possible to place objects in an outer packaging bearing characteristic, unmistakable features that cannot be copied, showing that the packaging of the contents has been performed by a particular supplier.
Known forgery-proof packaging and products are provided with holograms on their surface or they exhibit color coding or invisible features. Methods that have proved themselves in practice include, e.g., holograms. Examples are hologram labels or foil lids with integral holograms. Manufacturing holograms, however, involves enormous expenditure.
The object of the invention is therefore to provide at least a part of the surface of items, such as, packaging, packaging materials, packaging aids or products themselves, with an optical effect that can be produced in a cost favorable manner, but cannot be forged in a simple manner.
That objective is achieved by way of the invention in that the surface area exhibiting the optical effect exhibits at least two images separated a distance from each other by means of a transparent layer of material, and such that the distance between the images and the distance between two neighbouring elements forming the images are adjusted with respect to each other, and such that on altering the viewing angle the perceived overall image formed by the overlapping of the images is altered.
The invention makes use of a phenomenon known as the moirxc3xa9 effect. Moirxc3xa9 patterns are two dimensional images that result from the interference of two overlapping patterns. By displacing two immediately adjacent patterns, the moirxc3xa9 interference pattern also changes, leading to the known, changing light-dark image effects.
The present invention makes use of the changing moirxc3xa9 interference that occurs without mechanical displacement of the pattern. As a result of the mutual distance between the images, a spatial arrangement results, which on changing the angle of viewing leads to chang-ing moirxc3xa9 interference effects. By using reflecting materials it is possible, in the region of the angle of reflection, to observe a reflected image of one of the images instead of moirxc3xa9 interference patterns, while moirxc3xa9 interference occurs outside the range of the angle of reflection. The essential core of the invention lies therefore in the preparation of a three dimensional moirxc3xa9 pattern.
In order to create the effect according to the invention, the already known distances between neighbouring image elements in the moirxc3xa9 pattern have to be maintained. The said patterns may be made up of individual parallel lines or dots. In the simplest case of a line pattern the distance between neighbouring lines is always the same. In a simple arrangement two identical image patterns are arranged directly over each other and a distance from each other. It is possible, however, to displace regions of one image pattern with respect to the other image pattern e.g. by half the distance between neighbouring image elements, or to provide the first image with another pattern with the result that, on changing the angle of viewing, for example several changes from lightness to darkness and vice versa are observed. Of course images may also contain a combination of straight and curved lines or other image elements. As a result it is e.g. possible to incorporate trade names and the like signs with three dimensional moirxc3xa9 effects in the packaging material. In order to increase the protection against forgery further, one of the images may contain an additional structure to that of the pattern of lines. Another means of increasing protection against forgery and to conceal data is to design the image in such a manner that the additional information can be seen only after an additional filter has been superimposed on the image. Such filters are made up of a grid-type pattern, the dimensions of which are chosen to suit the dimensions of the line pattern.
The transparent layer of material that acts as a spacer between the images serves as a means of setting the desired minimum distance. This cannot be changed if the patterns are mounted immediately on the different sides or planes of the transparent material layer. If however the transparent layer lies on at least one of the images without being permanently attached there, i.e. at least one of the images is free of the layer of transparent material, then the distance from the pattern is variable and the three dimensional moirxc3xa9 effect is even more pronounced.
The layer of transparent material may be provided with an image on both sides. Another version is such that the layer of transparent material is made up of at least two partial layers and the images are deposited on the different partial layers. In a further version one of the images is deposited on an opaque foil e.g. an aluminium foil.
Instead of two images being deposited, one image may be the mirror image of the other. In this case one side of the layer of transparent material borders on the reflecting layer e.g. an aluminium foil with a highly reflective finish.
The images may be deposited in the form of coloured printed patterns. The printed image may be monochromatic or multi-coloured. As additional security one may employ colours that make the moirxc3xa9 pattern visible only under UV or IR light. Another possibility is for at least one image to be in the form of a surface structure with structural elements displaced with respect to their height e.g. as an embossed or etched pattern. Embossed or etched structures are suitable e.g. for depositing images on an aluminium foil. Embossed patterns may also be deposited on plastic or aluminium/plastic laminates using hot and/or cold embossing. Foils or laminates with an image pattern in the form of a surface structure are especially suitable for the production of tube laminates e.g. for manufacturing toothpaste tubes.
The images may also be created in the form of micro-perforations on an opaque foil, especially on an aluminium foil. The diameter or breadth of the perforations is thereby about 10 to 1000 xcexcm, preferably 50 to 200 xcexcm.
The images may also include basic matrix elements with individual image elements, the related image elements of different basic matrices being displaced with respect to each other in order to produce different local light-dark contrast or colours. The image preferably form patterns that produce defined light-dark contrast or colours as a result of various combinations of superposition. As these kind of images require extremely good matching of the super-imposed basic matrices to produce a good effect, this kind of image is required mainly in applications requiring a high degree of security against forgery.
The items according to the invention are manufactured using known methods. The image may be deposited e.g. by simultaneously printing on both sides of a transparent plastic film. The individual images may however also be printed on different films. The individual films, each bearing a printed image, are then joined by laminating them together to provide a packaging material. The proof against forgery is increased even further in that the laminating has to be performed on a machine with high precision control of the printing process.
At least one of the images may be deposited on a further layer of material which is free of the transparent layer of material. The optical effect is produced only when both layers of material are brought close to each other, the three dimensional moirxc3xa9 effect being additionally altered and reinforced. The two layers of material may e.g. be two foils or laminates that are joined together only at certain places, otherwise the other areas are able to adopt a variable distance to each other. Application possibilities are e.g. in pouch-type packaging made of two lamin-ates that are joined or sealed together only at the edges.
The item according to the invention may e.g. be any packaging material in the form of a packaging material or aid to packaging exhibiting a transparent layer of material upon which, additionally according to the invention, images have been deposited. The packaging material may be rigid, semi-rigid or flexible and may have a given shape or in particular be a foil-shaped material. Examples of shaped bodies are blown, deep-drawn and/or stretch drawn or deepened shapes such as bottles, wide-neck containers, beakers, dishes or bases of push-through packs or blister packs. Examples of foil-shaped materials are metal foils such as aluminium, steel, copper, silver or gold foils. Further examples of foil-shaped materials are papers such as silk paper having a weight per unit area of 20 to 30 g/m2 or highly whitened paper with a weight per unit area of 40 to 60 g/m2, cardboard, semi-cardboard or the like. Particularly important are films containing plastic e.g. plastics based on polyolefins, such as polyethylenes or polypropylenes, polyamides, polyvinylchloride, polyesters such as poly-alkylene-terephthalates and in particular polyethylene-terephthalate. The films containing plastic may be in the form of mono-films of plastic, laminates of two or more plastic films, laminates of metal and plastic films, laminates of papers and plastic films or laminates of papers and metal and plastic films. The individual plastic films may have a thickness e.g. of 12 to 200 xcexcm and the metal foils a thickness of 12 to 100 xcexcm. The individual layers of foil-shaped materials may be joined together by means of adhesives, laminating adhesives, bond-ing agents and/or extrusion coating, co-extrusion or laminating etc. Preferred plastic films are non-oriented or axially or biaxially oriented mono-films or laminates of two or more non-oriented or axially or biaxially oriented films of plastics based on polyolefins such as poly-ethylenes or polypropylenes, polyamides, polyvinylchloride, polyesters such as polyalkylene-terephthalates and in particular polyethylene-terephthalate.
The above mentioned packaging materials may form the items according to the invention in the form of packaging materials or aids to packaging. For example pouches, sachets, wraps, bags etc, may be manufactured out of the film-shaped packaging materials by stamping and sealing. By deep drawing and/or stretch drawing, films may be shaped into shaped packaging or shaped bodies such as bases of push-through packs or blister packs, or into wide necked containers, menu dishes, goblets, beakers etc. For example tubes (tube laminates) or lids for shaped packaging may be shaped out of the films in question. One may manufacture e.g. boxes such as collapsible boxes from cardboard type substrates. It is also possible to employ e.g. bottles blown out of plastics, or pre-formed packaging as a substrate and to apply the transparent material according to the invention to it. Closures, openings, seams, seams between a base part and the related lid etc. may be provided with a packaging material according to the invention in the form of a label, sealing strip, band, guarantee seal or outer seal. These last mentioned aids to packaging are as a rule film-shaped and are fixed to the container in question across an opening and fixed, e.g. adhesively bonded, welded, flanged or shrunk-fit onto the neighbouring part of the container. The packaging aid exhibits the trans-parent layer of material according to the invention and the images spaced apart by this. The structure according to the invention of the surface or area of surface on the item results in the specific intended optical effect on changing the angle of viewing. A forgery e.g. by photo-copying and using the photocopy as evidence of product origin or guarantee would be recog-nised immediately and easily, as changing the angle of viewing would not lead to the optical effect that is observed with the structure made according to the invention. In order that the aid to packaging e.g. sealing strip or band can be easily broken by the user, aids to tearing such as forms of weakening, notches or tear-off tabs may be provided. Also, component parts of packaging materials or aids to packaging may be employed in the form of easily torn or push-through plastic films, or plastic films containing fillers, or two poorly compatible plastic films.
Apart from the already mentioned use of the item according to the invention in the form of packaging or aid to packaging, another field of application is the forgery-proof manufacture of bonds, entry tickets and the like documents, whereby in addition to the forgery-proof design aspects it is possible to introduce special decorative effects.


The present invention generally relates to carbon dioxide (CO2) sensors. In one embodiment, the present invention relates to a carbon dioxide (CO2) sensor that incorporates lithium phosphate (Li3PO4) as an electrolyte and sensing electrode comprising a combination of lithium carbonate (Li2CO3) and barium carbonate (BaCO3). In another embodiment, the present invention relates to a carbon dioxide (CO2) sensor has a reduced sensitivity to humidity due to a sensing electrode with a layered structure of lithium carbonate and barium carbonate. In still another embodiment, the present invention relates to a method of producing carbon dioxide (CO2) sensors having lithium phosphate (Li3PO4) as an electrolyte and sensing electrode comprising a combination of lithium carbonate (Li2CO3) and barium carbonate (BaCO3).

Carbon dioxide sensors are becoming increasingly important for monitoring air-quality, measuring metabolic activity of animals and controlling combustion. While there are commercial sensors for air quality monitoring, no reliable sensor exits for high-temperature combustion-related applications. Among several designs for cost effective carbon dioxide (CO2) sensor with high sensitivity and selectivity, the potentiometric type sensor that consists of Na+ or Li+ conductor, a metal carbonate sensing electrode and a reference electrode were thought to be promising because they exhibit satisfactory EMF signals over a wide range gas concentrations and temperatures (see, e.g., Y. Saito and T. Maruyama; Recent Developments of Sensors for Carbon Oxides Using Solid Electrolytes; Mid State Ionics 28 to 30; (1988); pp. 1644 to 1647 and C. Park, C. Lee, S. Akbar, and J. Hwang; The Origin of Oxygen Dependence in a Potentiometric CO2 Sensor with Li-Ion Conducting Electrolytes; Sensors and Actuators B; 88; (2003); pp. 53 to 59). However, such sensors suffer from various drawbacks including but not limited to, limited effectiveness in humid conditions.
Potentiometric sensors based on a Na+ conductor such as NASICON® (see, e.g., Y. Saito and T. Maruyama; Recent Developments of Sensors for Carbon Oxides Using Solid Electrolytes; Mid State Ionics 28 to 30; (1988); pp. 1644 to 1647) attached to a Na2CO3 sensing electrode are reported to respond well to changes in CO2 concentration, following Nernst's equations when dry CO2 is used. The time required for 90% response is, however, reported to be several minutes at 500 to 700° C. A major problem with these sensors is that they suffer from strong interference from humidity.
Attempts to improve the sensor performance by modification of the sensing electrode material are described for the first time in references (see, e.g., N. Miura, S. Yao, Y. Shimizu, N. Yamazoe; High Performance Solid Electrolyte Carbon Dioxide Sensor with a Binary Carbonate Electrode; Sensors and Actuators B; 9; (1992); pp. 165 to 170; and S. Yao, Y. Shimizu, N. Miura, N. Yamazoe; Solid Electrolyte Carbon Dioxide Sensor Using Sodium-Ion Conductor and Li2CO3—BaCO3 Electrode; Japanese Journal of Applied Physics, Part 2,31; (1992); pp. 197 to 199). The sensor using binary carbonate (Na2CO3—BaCO3) reportedly exhibits a faster response than a sensor that employs Na2CO3 alone when BaCO3 content is more than a critical amount (see, e.g., S. Yao, Y. Shimizu, N. Miura, N. Yamazoe; Solid Electrolyte Carbon Dioxide Sensor Using Sodium-Ion Conductor and Li2CO3—BaCO3 Electrode; Japanese Journal of Applied Physics, Part 2,31; (1992); pp. 197 to 199).
Thus, there is a need in the art for improved CO2 sensors that work across a wide range of temperatures, as well as CO2 sensors that are less sensitive to humidity.


To provide a surface-emitting type semiconductor laser that has good luminescence property and can be driven at high speeds, and its manufacturing method. In a surface-emitting type semiconductor laser having a first mirror, an active layer and a second mirror formed above a substrate, the surface-emitting type semiconductor laser in accordance with the present invention includes a columnar section including at least a portion of the second mirror, a first electrode formed above the first mirror or below the substrate, a second electrode formed above the second mirror, a dielectric layer formed around at least a portion of the columnar section and in contact with the columnar section, and a heat radiating section formed around at least a portion of the columnar section through the dielectric layer, wherein the heat radiating section is in an electrically floating state.

The present invention relates to surface-emitting type semiconductor lasers and a method for manufacturing the same, and optical modules.
Heat generated at the time of driving a surface-emitting type semiconductor laser may deteriorate its characteristics. Heat generation of a surface-emitting type semiconductor laser is mainly caused at its columnar section that composes a vertical resonator. For example, Patent Document 1 proposes a structure in which a columnar section is embedded in a metal electrode such that the metal electrode has a heat radiation effect. By this structure, since the metal electrode has a high thermal conductivity, heat at the columnar section can be effectively dissipated. However, according to this structure, because the columnar section is covered by the metal electrode, a dielectric layer that is provided between the metal electrode and a member having a reverse polarity of the metal electrode needs to be thinned. For this reason, a large parasitic capacitance is generated at the time of driving the surface-emitting type semiconductor laser, and the high frequency characteristics of the element may be deteriorated.
[Patent Document] Japanese Laid-open Patent Application HEI 5-283796.

Surface-emitting type semiconductor laser and its manufacturing method, and optical module


A backlight unit applied on a display device is disclosed. The backlight unit includes a base having a frame, an optical film, an adhesive and a shading tape. The frame has at least a recess, and the optical film has at least a flange for inserting in the recess of the frame. The shading tape locates on the frame, and the adhesive locates between the frame and the shading tape only. No adhesive exists between the optical film and the shading tape.

1. Field of Invention
The present invention relates to a display device. More particularly, the present invention relates to a backlight unit of a liquid crystal display.
2. Description of Related Art
In the present market, the liquid crystal display (LCD) has many fields of application, including communications, hand-held mobile devices, dash-mounted displays in vehicles, monitors, notebooks and personal computers. Hence, LCDs could totally replace CRT monitors in the predictable future.
In small LCDs of hand-held mobile devices, a backlight unit and an LCD panel are combined by a black shading tape having adhesive on both surfaces thereof. Furthermore, the light source of any small LCD is usually located on a side of the LCD. Therefore, the backlight unit needs a light diffuser or prism sheet on the top thereof to diffuse light uniformly to properly backlight the LCD.
However, the shading tape is located on the light diffuser or prism sheet. If the LCD needs to be reworked, the light diffuser or the prism sheet is damaged when the shading tape is taken off. Hence, a light diffuser or a prism sheet is wasted, and the product cost is thus increased.

Backlight module comprising a shading tape to prevent leaking light from the lateral sides of the backlight module


A method may comprise determining, in an operating system instance, that an access control is being attempted to control an object by a user from a first client of a plurality of clients. Domain and client identifiers associated with the user may be determined. Any domain identifiers from a set and any client identifiers from a set may be accessed that may be associated with the object, where the domain identifiers may uniquely identify one or more domains and the client identifiers may uniquely identify one or more clients. One or more domain and client isolation rules may be evaluated to determine whether access control is permitted on the object based on whether a domain identifier is associated with both the object and the user and whether a client identifier is associated with both the object and the client. A permit or deny indication may be returned based on whether or not access control is permitted on the object.

Embodiments of the inventive subject matter generally relate to the field of computers, and, more particularly, to access control on a computer system.
Current computer system access control mechanisms in operating systems control access to resources such as login access, and file access. Some operating systems, such as conventional UNIX or UNIX-like operating systems, implement access control mechanisms of coarse granularity. On a UNIX system or UNIX-like system, system administration activities are typically performed through a root account. System administrators responsible for the administration of the system share/manage the password to the root account or use access control tools that allow access to the desired services after sufficient authentication. Some operating systems allow a finer granularity of control through role based access control (RBAC) mechanisms, where different usernames are assigned roles and only specified roles are allowed access.

Client based resource isolation with domains

International Business Machines Corporation


A method to improve the braking behavior of a vehicle is provided, in which it is not permitted to exceed a maximum allowable braking pressure difference between the braking pressures on the two wheels of one axle, and in which the maximum allowable braking pressure difference between the wheels of one axle is a function of at least one variable describing the vehicle dynamics. When an unstable behavior of the vehicle is recognized, the maximum allowable braking pressure difference between the wheels of the axle is maintained or reduced.

When braking on a road surface having widely different coefficients of friction with respect to the vehicle (this situation is referred to below as μ-split), it is possible that widely different braking forces may be applied in the vehicle. This results in a yaw moment about the vertical axis of the vehicle, which may result in skidding.
The driver now has the possibility to counteract the yaw moment by countersteering. Since as a rule, the yaw moment builds up very rapidly, the driver does not have enough time to react. Braking systems such as ABS (antilock braking system) or vehicle dynamics control systems such as ESP (electronic stability program) therefore limit the braking pressure on the high-μ side of the vehicle as a function of the low-μ side after the μ-split situation is recognized (the high-μ side is the side of the vehicle or of the road surface on which the higher coefficient of friction exists between the tires and road surface). This occurs based on the maximum allowable differential braking pressure.
A method for braking the wheels of a vehicle is shown in German Published Patent Application No. 42 25 983, wherein the buildup of braking pressure is influenced on at least one wheel to reduce a yaw moment produced by an ABS. In doing so, the braking pressure on the wheels of one axle is influenced such that the difference of the braking pressures of one axle does not exceed a maximum allowable value. This maximum allowable value is determined as a function of the speed of the vehicle and the transverse acceleration.

Method and device for improving braking behavior


Use of an import cache and/or an export directory with an agent within to respond to requests for data. The import cache stores data that has been imported through the agent. The export directory stores information related to data that has been exported through the agent. Because the import cache and the export directory only store data that has passed through the agent, not all data transferred within a system are tracked by a single import cache or export directory.

As the number of cache memories in a complex system increases, so too does the latency associated with checking the cache memories for a valid, or most recent, copy of requested data. This is a result of a typically hierarchical memory structure, which requires that the request be transmitted through multiple layers of the memory structure.
For example, if a processor or a memory controller broadcasts a request for a copy of a block of data (e.g., a cache line), each cache memory in the system receives the request and checks for the requested data. Each cache memory must also respond to the source of the request. This request-response protocol can be very bandwidth intensive in complex systems.
One technique that has been used in these complex systems is a directory that tracks the location of the valid copy of the requested data. A single, centralized directory can be used. Use of a centralized directory quickly increases the complexity and bandwidth requirements for a system because every transaction must be reflected by the directory. Thus, the directory must be checked and/or updated for each request and each response even if the directory does not provide any relevant information related to the request or response. However, the centralized directory can become a bottleneck to performance as the complexity of the system increases because many devices must search the directory for each request for data.

Hierarchical directories for cache coherency in a multiprocessor system