A delta-sigma modulator and delta-sigma modulation method according to the present invention are capable of ensuring a stable 1-bit signal having less distortion at the transition time from an audio signal reproduction state to soundless state while maintaining high sound quality during reproduction of an audio signal representing music or the like, and, at the same time, capable of maintaining high sound quality at the transition time from a soundless state to audio signal reproduction state. The delta-sigma modulator applies delta-sigma modulation to an input signal to output a 1-bit digital signal, and comprises an integration section that applies integration to the input signal, a quantization section that quantizes the integrated output from the integration section, a random noise generation section that generates a random noise signal whose gain has been adjusted based on the integrated output of the integration section, a detection section that detects a predetermined pattern from the input signal, and a changeover section that switches supply and suspension of supply of the random noise signal from the random noise generation section to the quantization section based on a detection result of the detection section.

1. Field of the Invention
The present invention relates to a delta-sigma modulator and a delta-sigma modulation method that apply delta-sigma (ΔΣ) modulation to an analog input signal or a digital input signal having a plurality of bits to generate a 1-bit digital signal.
2. Description of the Related Art
A ΔΣ modulated 1-bit audio signal has a format including a very high sampling frequency and a short data word length (for example, a sampling frequency of 64 times 44.1 kHz and a data word length of 1-bit) as compared with a format of data used in conventional digital audio (for example, a sampling frequency of 44.1 kHz and a data word length of 16 bits). The ΔΣ modulated 1-bit audio signal has an advantage of a wide transmissible frequency range. Even with the 1-bit signal, the ΔΣ modulation makes it possible to obtain a wide dynamic range in an audio range of low frequencies relative to the 64 times oversampling frequency. Taking advantage of this feature, the ΔΣ modulation can be applied to a recorder and data transmission for high-quality sound.
A ΔΣ modulation circuit itself is not an especially novel technique; the circuit is commonly used within a conventional A/D converter or the like, because the circuit configuration is suitable for integration into an IC and the circuit can achieve a high A/D conversion precision relatively easily. The ΔΣ modulated signal can be restored to an analog audio signal by passing the ΔΣ modulated signal through a simple analog low-pass filter.
Conventionally, in a ΔΣ modulator, when a signal with a certain constant frequency is input, the same signal is repeated within the ΔΣ modulator because the ΔΣ modulator has a feedback system, with the result that a distorted or unstable signal is output.
FIG. 1 shows a configuration of a conventionally-known ΔΣ modulator 100. The ΔΣ modulator 100 is a fifth-order ΔΣ modulator having five integrators 109, 111, 113, 115, and 117. Each of the integrators includes an adder and a delayer. For example, the integrator 109 includes an adder 109a and a delayer 109b.
An input signal input through an input terminal 101 is supplied to coefficient calculators 102, 103, 104, 105, 106, and 107 at a time. The coefficient calculators 102, 103, 104, 105, 106, and 107 are calculators for performing calculation control like gain control or filter control for an input signal and have feedforward coefficients ff0, ff1, ff2, ff3, ff4, and ff5, respectively.
The coefficient calculators 102, 103, 104, 105, and 106 perform calculation for the feedforward coefficients ff0, ff1, ff2, ff3, and ff4. The obtained respective calculation outputs are supplied to the adders 109a, 111a, 113a, 115a, and 117a of the integrators 109, 111, 113, 115, and 117. The coefficient calculator 107 performs calculation for the feedforward coefficient ff5. The obtained calculation output is supplied to the adder 118, and added to the integrated output of the integrator 117. The added output of the adder 118 is supplied to a quantizer 119.
The quantizer 119 applies quantization to the added output and supplies an output terminal 125 with the quantized output and, at the same time, feeds back the quantized output to coefficient calculators 120, 121, 122, 123 and 124 to be described later. The quantizer 119 generates a 1-bit output signal by applying quantization to the added output while referring to a threshold value of 0, which is constant at all times with respect to time. That is, the quantizer 119 applies quantization to the added output, which is an input signal, by determining two value levels using the threshold of 0, that is, determining whether the input signal is 0 or more, or less than 0.
The coefficient calculators 120, 121, 122, 123, and 124 hold feedback coefficients fb0, fb1, fb2, fb3, and fb4, used when the quantized output is fed back to the integrators 109, 111, 113, 115, and 117. The respective calculation outputs from the coefficient calculators 120, 121, 122, 123, and 124 are supplied to adders 108, 110, 112, 114, and 116, which are provided in front of the integrators 109, 111, 113, 115, and 117, and then fed back to the respective integrators.
In the case of, for example, attenuation control or gain control like fade-in or fade-out, the feedforward coefficients ff0, ff1, ff2, ff3, ff4, and ff5 of the coefficient calculators 102, 103, 104, 105, 106, and 107 are determined by a not-shown controller and the gain of input signals is controlled.
Further, in the case of filter control that passes or blocks only a desired frequency band, the feedforward coefficients ff0, ff1, ff2, ff3, ff4, and ff5 of the coefficient calculators 102, 103, 104, 105, 106, and 107, and the feedback coefficients fb0, fb1, fb2, fb3, and fb4 of the coefficient calculators 120, 121, 122, 123 and 124 are determined by the controller and input signals are subjected to filter control.
In the fifth-order ΔΣ modulator 100 shown in FIG. 1, when a signal with a constant repetition frequency, called a fixed pattern, is input, or when a 0 level signal is input at the time when the input of the ΔΣ modulator is opened, a distorted or unstable signal is output, because the ΔΣ modulator 100 has a configuration that feeds back a difference between the output of the integrator and the quantized value thereof.
FIG. 2 shows the frequency analysis result of a 1-bit output signal of 128 fs (fs=44.1 kHz) in the case where a signal of a fixed pattern is input. FIG. 3 shows the frequency analysis result of a 1-bit output signal of 128 fs (fs=44.1 kHz) in the case where a 0 level signal is input as an input signal. As can be seen from FIGS. 2 and 3, the configuration that feeds back a difference between the output of the integrator and the quantized value thereof when a signal of a certain fixed pattern or 0 level signal is input makes noise shaping, which is one of the features of the ΔΣ modulator, ineffective, with the result that a distorted or unstable signal is output.
To avoid this, in the conventional ΔΣ modulator, a random noise signal is input through the input side component of the ΔΣ modulator (for example, through the adder 108 in the case of the ΔΣ modulator 100 of FIG. 1). Alternatively, a random component is inserted at the front stage of the quantization performed in the ΔΣ modulator to eliminate the fixed pattern.
However, the insertion of a random component may degrade the signal characteristics. To cope with this problem, there is available a method that calculates an adequate amount of the random component and inputs it equivalently to the quantizer, as disclosed in Jpn. Pat. Appln. Laid-Open Publication No. 2002-314425 (Patent Application No. 2001-157947) by the present applicant. The delta-sigma modulator disclosed in Jpn. Pat. Appln. Laid-Open Publication No. 2002-314425 controls a threshold level to be referred to in quantization processing of the quantizer in a variable manner with respect to a time axis in order to input the calculated adequate amount of random component equivalently to the quantizer.
FIG. 4 shows a configuration example of the above mentioned delta-sigma modulator 130 according to Jpn. Pat. Appln. Laid-Open Publication No. 2002-314425 that uses the adequate amount of random component. The ΔΣ modulator 130 is a fifth-order ΔΣ modulator having five integrators 139, 141, 143, 145, and 147. Each of the integrators includes an adder and a delayer. For example, the integrator 139 includes an adder 139a and a delayer 139b.
In the delta-sigma modulator 130, a multi-channel audio signal represented by using a 1-bit audio data from CH 1 to CH 6 is reproduced from, for example, an optical disc 131 like a Super Audio CD (SA-CD) by a not-shown disc reproduction apparatus and supplied to coefficient calculators 132, 133, 134, 135, 136, and 137 at a time. The coefficient calculators 132, 133, 134, 135, 136, and 137 are calculators for performing calculation control like gain control, filter control, or mix control for the respective 6-channel multi-channel audio signals and have coefficients b0, b1, b2, b3, b4, and b5 for the respective calculation processes. In the case of the mix control, the coefficients b0, b1, b2, b3, b4, and b5 are determined by a controller to be described later and the respective multi-channel signals are mixed.
The coefficient calculators 132, 133, 134, 135, and 136 perform calculation for the coefficients b0, b1, b2, b3, and b4. The obtained respective calculation outputs are supplied to the adders 139a, 141a, 143a, 145a, and 147a of the integrators 139, 141, 143, 145, and 147. The coefficient calculator 137 performs calculation for the coefficient b5. The obtained calculation output is supplied to the adder 148, and added to the integrated output of the integrator 147. The added output of the adder 148 is supplied to an adder 149 provided in front of a quantizer 150.
Further, a random noise signal is supplied to the adder 149. The random noise signal has been set in an adequate amount by a random noise generator 152 that generates a random noise signal like a dither signal. Thus, the adder 149 adds an adequate amount of the random noise signal to the added output of the adder 148 and supplies the quantizer 150 with the added output including the random noise signal.
The random noise signal generator 152 supplies the quantizer 150 with the random noise signal whose gain has been set in an adequate amount based on the integrated output of the last stage integrator 147 through the adder 149. That is, a gain calculator 151 calculates the gain based on the integrated output of the last stage integrator 147 and sets in the random noise generator 152.
The gain calculator 151 calculates a gain by which a random noise signal Rn is multiplied such that the absolute value of the random noise signal Rn becomes less than or equal to a variable threshold Δq (|Rn|≦Δq) which is based on the amplitude of the signal inside the last stage integrator 147.
The adder 149 adds the random noise signal Rn whose gain has been adjusted as described above to the integrated output of the last stage integrator 147 and, the quantizer 150 quantizes the added output signal.
The adequate amount of gain that has been calculated by the gain calculator 151 is equal to the threshold ±Δq of the quantizer, the threshold being variable with respect to time. The variable threshold Δq is calculated based on the amplitude of the signal generated in the last stage integrator 147. More concretely, the variable threshold Δq is obtained as SαDend which is calculated by multiplying the maximum value Dend of the amplitude of the signal generated in the last stage integrator 147 by a predetermined constant Sα.
FIG. 5 shows a conceptual view of a quantizer using the threshold variable with respect to time. The adequate amount of ±Δq is, for example, not more than 75 with respect to ±1.0 of the quantizer. When an amount that exceeds that value is input, delta-sigma modulation becomes unstable, making it impossible to suppress distortion.
The quantizer 150 applies quantization to the added output to which the adequate amount of random noise signal has been added and supplies an output terminal 159 with the quantized output as well as feeds back the quantized output to coefficient calculators 153, 154, 155, 156, and 157 to be described later.
The coefficient calculators 153, 154, 155, 156, and 157 hold feedback coefficients a0, a1, a2, a3, and a4, used when the quantized output is fed back to the integrators 139, 141, 143, 145, and 147. The respective calculation outputs from the coefficient calculators 153, 154, 155, 156, and 157 are supplied to adders 138, 140, 142, 144, and 146, which are provided in front of the integrators 139, 141, 143, 145, and 147, and then fed back to the respective integrators. The ΔΣ modulator 130 of FIG. 4 having the configuration described above can apply quantization to an input signal at an optimal variable threshold level.

Delta-sigma modulator and delta-sigma modulation method


Disclosed is a device and method for compensating for phase distortions in a base station of an OFDMA-based cellular system. The method comprises receiving OFDM symbols from a plurality of mobile stations, canceling a symbol guard interval using a reference timing signal, and performing an FFT (fast Fourier transform) process on the OFDM symbols; dividing the OFDM symbols that have undergone FFT processing into subchannel groups of the mobile stations; restoring phases of the OFDM symbols divided into subchannel groups; and performing channel estimation and equalization on the restored OFDM symbols for each mobile station to thereby perform a demodulation process.

(a) Field of the Invention
The present invention relates to a device and method for compensating for phase distortions in a base station of an OFDMA (orthogonal frequency division multiple access) based cellular system. More specifically, the present invention relates to a device and method for compensating for phase distortions in a base station of an OFDMA-based cellular system, in which the device and method allow multiple access in the uplink of the OFDMA-based cellular system.
(b) Description of the Related Art
Following developments in next-generation mobile communication systems, many methods have been proposed for providing various services including high-quality and high-speed multimedia services. However, the deterioration in performance caused by multipath fading channels in mobile communication environments has become serious impediments to realizing such services.
Therefore, many techniques for overcoming the deterioration in performance caused by multipath fading have been developed and used. A drawback of these techniques, however, is that although they minimize such performance deterioration, the techniques require the design of a complex receiver.
The OFDMA method has been suggested for easily solving the problem of deterioration in performance caused by multipath fading by using a simple demodulator.
In the OFDMA method, a total of N subcarriers are divided into groups in a single OFDM symbol and in such a manner that the subcarriers are not repeated, and one of the divided groups (or subchannels) is allocated to each mobile station user.
In the OFDMA method, each mobile station loads data to a subcarrier in the group and transmits the data during a predetermined time frame in the reverse link case. Since the subcarriers included in the subchannel allocated to users who stay in a single cell belong to a single OFDMA symbol, it is necessary for a base station receiver to perform synchronization between each of the subchannels received from the mobile station. That is, in order to perform accurate demodulation, it is necessary that the base station receiver perform the same FFT (fast Fourier transform) at the same symbol timing.
Hence, OFDMA flexibly processes various services for the multitude of requests made by users, but results in the deterioration of performance compared to other multi-user access methods when the multiple users are not synchronized in the uplink.

Device and method for compensating for phase distortion in base station of OFDMA-based cellular system

Electronics and Telecommunications Research Institute


Systems and methods perform comparison of data represented as charts, for example, bar graphs, pie charts, line charts or stacked bar charts. The charts present visual representations mapping source values to target values. A user can select charts associated with a data records for comparison from an index of data records. The user selects a chart and a particular source value from the reference chart. The target values corresponding to the source value from other charts are compared against the target value from the reference chart. An aggregate of the target values associated with the source value from each chart may be presented to the user. The user can also use multi-touch input to select object representing data and drag them to perform actions associated with the objects. The actions performed on the objects depend on the locations of the objects as the user drags them.

1. Field of Art
The disclosure generally relates to user interface for presenting data records as charts on a display device, and in particular to comparing data presented as charts.
2. Description of the Related Art
There are several ways of using charts or graphs to visually present statistical data available in reports including, for example, bar charts, pie charts, line graphs, and scatter graphs. Users often have to compare related data from one or more reports. For example, a user may want to compare reports that represent data associated with different time intervals, such as reports describing sales statistics for two different quarters. The user may view the individual reports as charts. However for comparison purposes the user may have to identify matching data points from the charts and manually compare the values. The comparison may be performed using a calculator or an analysis tool, for example, a spreadsheet. Such manual comparison can be a tedious and slow process. Alternatively, if the data is stored using a database management system, the user may be able to generate customized reports that compare data from existing reports. However, writing customized reports can be a complex task in itself, requiring expertise with the database system. Data comparison is often performed by business experts who are unlikely to also have the expertise required for handling the complexities of reporting systems. Often, enterprises engage in complex and expensive processes of gathering requirements from business experts, preparing specifications for experts in reporting systems, and go through the development cycles for preparing customized reports required by the business experts.


A system is disclosed for detecting a malfunction in a fuel/lubricating oil heat exchanger which includes a pressure differential generator located in the pressure balancing conduit connecting the lubricating oil reservoir with the lubricating enclosure. The pressure differential generator may be a cavitation venturi tube having a throat which, under normal conditions, allows sub-sonic fluid flow which enables the air in the lubricating enclosure to freely communicate with the interior of the oil reservoir and vice versa. When fuel is mixed with the lubricating oil, due to a malfunction in the fuel/oil heat exchanger, the fuel enters the lubricating oil reservoir causing the fluid level within the reservoir to rise and overflow. The cavitation venturi tube is then supplied with a comparatively hot mixture of fuel and oil having a vapor pressure approximately equal to the reference pressure within the lubricating enclosure. Under these conditions, vaporization takes place at the throat of the venturi tube which effectively blocks any fluid flow through the venturi. As a result, the pressure within the oil reservoir increases.

The present invention relates to a leak detector for detecting leaks in an oil/fuel heat exchanger in an aircraft turbojet engine lubricating circuit, more particularly such a detector which relies upon an increase of pressure in the oil reservoir caused by fuel mixing with the lubricating oil.
It is conventional practice in aircraft turbojet engines to provide lubricating oil for lubricating various rotating element of the turbojet engine and to cool the lubricating oil by passing it through a fuel/oil heat exchanger which is also connected to the fuel supplied to the engine. The turbojet engine components to be lubricated, such as the turbine bearings, are mounted in an enclosure having a vent hole to establish a reference pressure within the enclosure. A supply pump feeds the lubricating oil from a lubricating oil reservoir through a supply conduit to a spray device located in the enclosure which sprays the oil onto the elements to be lubricated. The lubricating oil circuit may include a return pump which returns the used lubricating oil to the reservoir. Also, an oil filter may be inserted into the return conduit downstream of the return pump. The oil/fuel heat exchanger is typically located between the oil filter and the lubricating oil reservoir.
In order to maintain a slightly excess pressure inside the lubricating oil reservoir, a pressure balancing conduit connects the reservoir to the lubricating enclosure. To compensate for imbalances between the flows of the supply pump and the return pump, the balancing conduit allows air to freely transfer between the oil reservoir and the lubricating enclosure such that the pressure in the reservoir will be substantially equal to the reference pressure in the lubricating enclosure.
Aircraft procedures during aircraft flight require the stopping of the turbojet engine if there is a lubricating circuit malfunction. Means are provided to measure the pressure differential between the outlet pressure of the supply pump and the reference pressure within the lubricating enclosure. When this pressure differential becomes less than a predetermined value, an alarm is transmitted to the aircraft pilot so that he may take the appropriate action.
The pressure of the fuel circulating through the heat exchanger is significantly higher than the outlet pressure of the return pump for the lubricating oil. In case of a malfunction or a leak between the two fluid circuits in the heat exchanger, fuel will be introduced into the lubricating circuit due to its higher pressure. The oil diluted by fuel will seriously degrade the engine components and presents the danger of engine fires, especially when the engine has stopped after the aircraft is on the ground. Under these circumstances, the air/oil labyrinth seals of many engine parts lose their effectiveness, which may allow an oil/fuel mixture to come into contact with high temperature engine components.

Pressure system for detecting malfunctions of a fuel/oil heat exchanger

Societe Nationale d'Etude et de Construction de Moteurs d'Aviation (S.N.E.C.M.A.)


According to an alarm correlation analysis method, apparatus, and system, alarm analysis rules are grouped according to a certain policy; each alarm analysis rule group is correlated with one analysis engine, and the analysis engine performs, according to an alarm analysis rule in the alarm analysis rule group corresponding to the analysis engine, correlation analysis for an alarm that has a correlation with the alarm analysis rule group, so that multiple analysis engines implement concurrent analysis on a large quantity of alarms, thereby fully utilizing a multi-core resource, and improving efficiency of alarm correlation analysis.

As communications technologies rapidly develop, a scale of a communications network continuously enlarges and a structure of the communications network becomes more complex. The communications network is formed by interconnection of a large quantity of devices and links. When a certain device or link is faulty, an alarm is generated. In addition, because the device or the link may be associated with multiple devices or links, when the device or the link is faulty, a device or a link that is associated with the device or link may become faulty and generate an alarm, where the alarm generated by the faulty device or link is a cause alarm, and the alarm generated by the device or link that is associated with the device or the link is a correlative alarm. When alarms are generated in the communications network, correlation analysis on the generated alarms is required to analyze the cause alarm and the correlative alarm from the generated alarms, so that operation and maintenance personnel process the cause alarm, thereby ensuring normal running of the communications network. Automatically identifying the cause alarm by using a function of correlation analysis so that the operation and maintenance personnel process the cause alarm has become an important means for quick troubleshooting, which greatly improves the troubleshooting efficiency of the operation and maintenance personnel. At present, the function of correlation analysis still adopts single-engine analysis, and an existing processing mechanism has the following problems: an efficiency bottleneck exists, and a single engine has an efficiency upper limit, failing to meet an increasingly high requirement; and multi-core resources cannot be fully utilized to exert an advantage of parallel processing.

Alarm correlation analysis method, apparatus and system


An apparatus for supporting one or more theatrical panels and, in a more specific aspect, a carriage assembly adapted for such task in association with a horizontal track having an upper guide surface and a lower guide surface, provide horizontal movement quietly, smoothly, with low frictional resistance and in a highly-linear fashion with low rock and sway. A horizontal track comprising an upper guide surface and a lower guide surface supports a carriage assembly having a plurality of upper guide wheels and a plurality of lower guide wheels. The upper guide wheels are supported in rolling contact with the upper guide surface and the lower guide wheels are supported in rolling contact with the lower guide surface. The axles supporting the upper guide wheels are preferably horizontally offset from vertical lines extending through any of the axles supporting the lower guide wheels. The guide wheels are preferably resilient at least at the surface and grooved to engage the guide surfaces.

A number of devices have been used in the art to facilitate the horizontal movement of scenery panels for staged productions of various types. Typically, they have taken forms similar to drapery rods.
Among related devices are a carriage and rail assembly for a curtain described in U.S. Pat. No. 5,542,149 to Yu. Figures 6 and 7 of that patent set forth a prior art device which includes twin horizontal tracks for guiding a carriage suspended on axles connecting pairs of wheels riding in the tracks, with the curtain suspended between the tracks. Various stresses on the carriage during movement of a supported curtain, can cause uneven loading and upward and sideward biasing of the wheels. This subjects the wheels to damage, breaking and difficult movement. To improve on this structure, pairs of displacement-limiting rollers are added to oppose upward and sideward displacement from the tracks. While an apparent improvement on the prior art, this arrangement requires a total of ten wheels per carriage for carrying a single curtain. It would be desirable to reduce the complexity of such a carriage and rail assembly and yet provide the capability to hold and convey a plurality of curtains or scenery panels.
In U.S. Pat. No. 4,073,034, Martens describes a system for supporting and moving panels of a multi-panel door which also includes upper and lower rollers to maintain alignment on a track. Two door panels are shown supported on the same track and move in coordinated fashion, with one moving at twice the speed of the other. There is no provision made for two parallel tracks for independently moving two individual panels or for supporting panels on two sides to provide greater stability against sway transverse to the direction of movement and resulting torsional dislodgment in situations where that might be a problem. In addition, the device described cannot provide good stability against rocking in the direction of movement unless a multiplicity of hangers are provided for each panel. It would be desirable to have a carriage assembly having greater stability and versatility.
In U.S. Pat. No. 4,698,876, Karita shows a variation on the Martens-type of arrangement, but enables a magnetic force to support at least a part of the weight of the door. The improvements described in the patent do not, however, adapt it to the needs addressed by the present invention.
The above and other drapery and panel door hangers are available, but the art of supporting and moving theatrical scenery panels is awaiting the development of an apparatus for supporting such panels and facilitating their horizontal movement quietly, smoothly, with low frictional resistance and in a highly-linear fashion with low rock and sway.

Theatrical scenery carriage and movement mechanism


A method for simulating a set of instructions to be executed on a processor including performing a performance simulation of the processor over a number of simulation cycles. Modeling, in a frontend component, branch prediction and instruction cache is performed providing instructions to the instruction window, and modeling of an instruction window for the cycle is performed. From the simulation, a performance parameter of the processor is obtained without modeling a reorder buffer, issue queue(s), register renaming, load-store queue(s) and other buffers of the processor.

Processor simulation is useful to evaluate various processor configurations without the hardware being available. Simulation is therefore heavily used during the design process of a new processor for evaluating design trade-offs and novel research ideas.
One of the first simulators was described by Austin et al. in IEEE Computer 35(2) (2002) 59-67, describing an architectural simulator for superscalar out-of-order processors. This was widely used in computer architecture research in the 1990s and early 2000. This architectural simulator models an out-of-order processor using a structure called the Register Update Unit (RUU) which models the instruction window of an out-of-order processor in its early days (such as the HP PA-8000; the instruction window was called the 'instruction reorder buffer' in the PA-8000). Later designs split up the instruction window into two separate structures, the reorder buffer and the issue queues (also called reservation stations); the reorder buffer contains all in-flight instructions and the issue queues only contain instructions that aren't finished yet with their execution. The latter was performed because it was realized that the increasingly complex processors could not be simulated anymore in an accurate manner by the simulator described by Austin. The split design meant in fact an efficiency optimization compared to the instruction window: the issue queue was smaller and therefore faster and more energy-efficient to perform the CAM lookups during issue. Contemporary simulators, such as GEMS, M5, PTLSim and others, model this split issue queue versus ROB design. Sim-alpha is a validated version of SimpleScalar to model the Alpha 21264 processor. Sim-alpha models the processor in much higher detail compared to SimpleScalar, including ROB, issue queues, clustered microarchitecture, register renaming, load-store buffers and queues.
At present, architects in industry and academia often rely heavily on cycle-level (and in some cases true cycle-accurate) simulators. The limitation of cycle-level simulation is that it is very time-consuming. Industry single-core simulators typically run at a speed of 1 KHz to 10 KHz; academic simulators typically run at tens to hundreds of KIPS (kilo instructions per second). Multi-core processor simulators exacerbate the problem even further because they have to simulate multiple cores, and have to model inter-core communication (e.g., cache coherence traffic) as well as resource contention in shared resources. Besides concerns regarding the development effort and time of detailed cycle-level simulators, this level of detail is not always appropriate, nor is it called for. For example, early in the design process when the design space is being explored and the high-level microarchitecture is being defined, too much detail only gets in the way. Or, when studying trade-offs in the memory hierarchy, cache coherence protocol or interconnection network of a multi-core processor, cycle-accurate core-level simulation may not be needed.
Current days, architectural simulation thus faces two major challenges. First, it is extremely time consuming: simulating an industry-standard benchmark for a single microprocessor design point easily takes a couple days or weeks to run to completion, even on today's fastest machines and simulators. Detailed processor simulation is very slow (5 to 6 orders of magnitudes slower than native execution), which reduces the number of configurations that can be explored in a limited time budget. Culling a large design space through architectural simulation of complete benchmark executions thus simply is infeasible. While this is already true for single-core processor simulation, the current trend towards multi-core processors only exacerbates the problem. As the number of cores on a multi-core processor increases, simulation speed has become a major concern in computer architecture research and development. Second, developing an architectural simulator is tedious, costly and very time consuming.
There have been two approaches to reduce simulation time in modern day architectural simulation: reducing the number of instructions to be executed and speeding up the simulation process itself. Reducing the number of instructions to be executed is done using sampling (SMARTS, SimPoint) or reduced synthetic traces (statistical simulation). Speeding up the simulation has been done using simple one-IPC models, which can be highly inaccurate. Another technique uses an analytical model (interval simulation), which cannot be used in all environments and for all purposes, and is less accurate than this invention.
There is still need for a simulator for accurately and fast simulating the complex processors of today.

Instruction window centric processor simulation


In an A/D converter including a switched capacitor integration circuit, to suppress an effect of a noise generated in the switched capacitor circuit while suppressing increase in a forming area of the circuit. A first-stage integrator of a differential input type A/D converter includes first and second switched capacitor circuits, and includes a noise cancel circuit for generating a noise cancel signal to cancel a kickback noise generated due to switching operation thereof.

1. Field of the Invention
The present invention relates to an analog/digital converter (A/D converter) including an integration circuit having a switched capacitor circuit in an input section of an analog signal.
2. Description of the Background Art
A technique to convert the analog signal to a 1-bit digital signal by delta sigma (ΔΣ) modulation is widely known in the field of the analog/digital converter (A/D converter). A delta sigma modulation circuit includes an integration circuit and a quantizer, and a switched capacitor integration circuit is conventionally frequently used as the integration circuit (refer to "Applied Technology of Signal Processing by OP Amplifier, All About OP Amplifier, Vol. 2", Analog Devices, CQ Publishing, Feb. 1, 2005, p. 115, for example).
In the A/D converter in which the switched capacitor integration circuit is used in an input section of the analog signal, a driver circuit for inputting the analog signal to the A/D converter is connected to the switched capacitor circuit. In such a case, a problem occurs that a spike-like noise (referred to as a "kickback noise") is generated when rapidly charging a sampling capacitor in the switched capacitor circuit, and this is superimposed on an analog signal waveform (detail thereof will be described later). Then, accuracy of the input analog signal is destroyed, so that deterioration in accuracy of A/D conversion occurs.
As measures for solving the problem, it is considered to improve drive ability of the above-described driver circuit and to provide a circuit (refer to a circuit "LPF in FIG. 8) including a capacitative element for supplementing transient outflow and inflow of an electric charge and resistor to prevent an amplifier output of a previous stage from oscillating due to the capacitative element in the input section of the A/D converter, as suggested in "Applied Technology of Signal Processing by OP Amplifier, All About OP Amplifier, Vol. 2", Analog Devices, CQ Publishing, Feb. 1, 2005, p. 115. However, any of the measures is not preferable for increasing a forming area of the circuit. Meanwhile, in this specification, the circuit including the above-described capacitative element (C) and resistor element (R) is referred to as an "RC low-pass filter" for convenience of description.


An intelligent tire pressure management system capable of real-time tire pressure monitoring, vehicle load detection, and automatic tire inflation and deflation for maintaining optimal tire pressure in a commercial vehicle. Additional functions include counting tire rotations for calculating and recording distance travelled for each tire, and detecting wheel sliding due to locked-up tires. The system includes a chassis-mounted control box connecting to the vehicle air supply, a hubcap-mounted dual wheel valve apparatus integrated with a rotary union assembly that connects through the vehicle hollowed axles to the air tubes from the control box. The inflation/deflation supporting dual wheel valve apparatus has an embedded electronic unit that monitors individual tire pressure and temperature in real time, and communicates with the control box over the power line. Furthermore a load sensor integrated with the control box provides the system with the current vehicle load information. With readily available real time tire pressure data and current vehicle load information, this system can intelligently adjusts tire pressure to the desired level when necessary and, as a result, prolongs tire life, improves fuel economy, reduces the vehicle maintenance costs, and promptly alerts the driver of low, leaky or flat tire conditions for enabling the driver to take immediate corrective actions.

Keeping proper tire pressure is a very important aspect of vehicle maintenance. Driving on underinflated or overinflated tires compromises stopping distance, ride and handling, fuel economy, tread wear, and load bearing. Over-inflation decreases traction, causes the tread to wear more quickly in the center, and wear suspension components faster. Underinflated tires have greater flex in the tires' sidewalls. Excessive deflection causes wear closer to the sides, leads to more heat buildup that speeding wear, and greatly reduces fuel economy. Each tire is rated to carry a maximum amount of weight at a prescribed tire pressure. When there is insufficient air pressure in a tire to support a specific load, the extra heat generated in the tire can cause it to fail. Properly inflated pressure during vehicle operation can achieve optimal tire deflection for the best grip and will help to provide even wear and longer life of the expensive tires with substantially improved fuel economy. The concept of a tire inflation system has been implemented on commercial and military vehicles for many years. Many military vehicles are equipped with a central tire inflation system (CTIS) which incorporates both inflation and deflation features, allowing the pressure of the tire to be manually adjusted in response to the road conditions experienced by a vehicle. For example, on relatively soft terrain, the tires could be deflated somewhat to improve traction. In contrast, on harder surfaces, such as paved roads, the tires could be more highly pressurized. Nevertheless, currently available central tire inflation systems do not have real time tire pressure monitor capabilities nor able to intelligently and automatically manage tire pressure with respect to pressure variation, vehicle load and terrain conditions. For commercial vehicles, current tire inflation systems are designed to inflate tire pressure only. Their primary function is to ensure that tire pressure does not fall below a preset tire pressure. Without deflation capability, such systems often can only maintain a preset pressure when the tires were cold but unable to adjust the pressure when the tires got hot and might become overly inflated. Furthermore, one of the most important variables affecting the ideal amount of tire pressure is the load the vehicle tires need to carry but inflation-only system is unable to adjust the tire pressure in accordance to the vehicle load.
U.S. Pat. No. 6,145,559 issued to Rupert Henry Ingram on Nov. 14, 2000 discloses automated tire inflation by using a rotary union to connect a rotary axle and hub assembly. The assembly includes a rotary air connection assembly thread-ably mounted on the hubcap.
U.S. Pat. No. 6,585,019 B1 issued to Anthony L. Ingram on Jul. 1, 2003 discloses a rotary union assembly for use in an automatic tire inflation system for maintaining the desired pressure in the tires on a trailer or other vehicle having pressurized axles. The assembly communicates the valve stems on a pair of adjacent tires with the axle interior through the use of a flexible tube extending between a stationary first fitting thread-ably engaged in the axle spindle and a rotary housing secured against the outside end surface of the hubcap so as to be positioned exteriorly of wheel lubrication compartment and rotatable with the hubcap.
U.S. Patent US 2004/01732296 A1 issued to Jay D. White on Sep. 9, 2004 discloses a tire inflation system include an air supply in selective fluid communication with a tire via a pneumatic conduit. An inflation pressure of the tire is measured with a set-up procedure and the tire is inflated with an extended-pulse procedure.
U.S. Patent US 2006/0018766 A1 issued to Edmund A. Stanczak on Jan. 26, 2006 discloses a tire inflation system includes a hose that connects to a tire via a valve stem. A control valve is in fluid communication with the hose and senses when pressure falls below a predetermined minimum value. When this occurs, the control valve automatically opens to re-supply air to the tire until the predetermined minimum value is achieved.
U.S. Pat. No. 6,144,295 is issued to Brian Adams on Nov. 7, 2000 discloses a central tire inflation system for a work vehicle. The central tire inflation system controls the inflation pressure in the tires of a work vehicle. The central tire inflation system may be placed in an automatic or manual mode. In the automatic mode, the system make changes to the tire pressures according to the tire parameters, terrain conditions, and the operating loads placed on the tire.
U.S. Patent US 2007/0204946 A1 is issued to Martin A. Medley on Sep. 6, 2007 discloses a central tire inflation wheel assembly and valve. The valve includes a main body that is position-able in a sealed and recessed or embedded configuration within the aperture in the wheel rim in communication with the interior of the tire and with a pressurized air source that is used to inflate or deflate the tire.
Typically, these commercial tire inflation systems teach how to inflate air into tires through a rotary union with a one-way check valve that does not have tire deflation functionality. Such system mostly must operate continuously or periodically without knowing current tire pressure in individual tires. When inflation is not activated such systems are unable to detect any flat or leaky tire conditions. While military central tire inflation systems can perform tire pressure inflation and deflation functions, in order to avoid over burning the hub seal, these systems mostly can only check tire pressure during the periodic inflation and deflation activation time. Moreover, these teachings do not address nor provide intelligent tire management solutions to resolve many practical issues, as described below:
(i) Tire Inflation and Deflation with Real Time Monitoring
Properly pressurizing and monitoring tires in real time are utmost important for driving safety and for prolonging the life of tires. However prior commercial tire inflation systems only inflate tires and do not monitor individual tire pressure. It is technically challenging to monitor each tire pressure in real time for tire inflation systems. Currently there are no commercially available tire inflation systems incorporating embedded electronic unit into each wheel valve assembly for monitoring individual tire pressure, and inflate or deflate the tires only when tire pressure is deviate from a predetermined optimal level. Prior teachings generally do not present practical methods to combine real time tire pressure monitor with tire inflation and deflation for commercial vehicle applications.
(ii) Intelligent Tire Pressure Management.
There are many tire inflating systems available on the market and most of them are designed for trailer installation. Such systems mostly use compressed air from the vehicle air tank to inflate tires when tire pressure fell below a preset level. Air from the existing trailer air supply is routed to a control box and then fed into air tubes installed inside each hollowed trailer axle. The air tubes run through the axles to carry air through a rotary union assembly joined at the end of the wheel spindle in order to distribute air to each tire via the valve stem. Generally tire inflation systems do not support intelligent tire pressure management, must inflate the tires continuously or periodically for every trip, and often overly inflate the tires.
Existing tire inflation systems generally use an in-line flow sensor to monitor air flow and do not have direct pressure readings from the tires for controlling the inflation, therefore such systems typically do not know if preset pressure was maintained in the tires. Mostly such systems would deduce that there might be leaky or flat tires if overall pressure was still low after inflating a period of time. This indirect detection of air leak and flat tire is unreliable and usually belated. With frequent system operation, the excessive work load putting on the rotary hub seal unit and the air compressor will wear out the parts sooner and would lead to more expensive vehicle maintenance and even unsafe driving conditions. A tire inflation and deflation system integrated with real tire pressure monitor manages pressure intelligently based on real-time tire pressure data and vehicle load, adjusts tire pressure only when necessary and, as a result, works less and thereby reduces the vehicle maintenance costs. More importantly such an intelligent system improves vehicle safety for it would be able to promptly alert the driver low, leaky or flat tire conditions and enabling the driver to take immediate corrective actions.

Intelligent tire inflation and deflation system apparatus


Symbologies for encoding data, as well as methods of encoding and decoding thereof are described. The symbologies may have a plurality of pixels arranged in a plurality of patterns on or in a substrate. Furthermore, each of the plurality of pixels may have one or more optical properties that each provides one or more types of non-interacting data.

Symbologies, such as matrix codes and the like, are becoming increasingly common for use in tagging and tracking solutions. Reading devices, such as barcode scanners and smartphone apps that use a camera to view and decode the symbology are common and easy to obtain. Most reading devices are capable of viewing and decoding a wide variety of symbologies, such as, for example, one-dimensional barcodes and many two-dimensional matrix code technologies. However, the symbologies are currently limited in the amount of data they are capable of encoding (e.g., a v.40 QR code with error correction level L can encode 4,296 alphanumeric characters).
Because of an increasingly common need to encode more data on a symbology, several new technologies have modified the symbologies in ways that allow for additional data to be encoded. However, some of these technologies still fail to encode enough data, and some of these technologies also require proprietary reading devices that may be expensive and/or difficult to obtain.


An on-site ESS management device includes an editing part for selectively grouping a plurality of grid parts when a plurality of grid parts including at least one of a battery and a power converter connected to the battery are provided, a selection part for selecting a specific group, and a management part for managing the power input and output of each grid part included in the specific group.

An energy storage system (ESS) consists of a battery, a PCS, and a PMS (EMS). The PMS provides an algorithm and UI in such a manner to issue, control, monitor, and operate instructions so that the battery is charged and the PCS is converted in power in connection with BMS information of the installed battery and PCS status information when the customer wants to charge the battery.


Most motor vehicles contain an audio such as a radio, cassette player or compact disc player. A housing generally having a box-like shape and an open end surround the actual hardware. A cover fits over the open end of the housing. The present invention provides a positive means for attaching and holding the front cover to the housing. A lip section of the cover is tightly held between upper and lower tabs integral with the housing. The interference fit created by the tabs tends to reduce the possibility of annoying rattling or buzzing sounds during vehicle operation due to a loose fit of the cover onto the housing.

1. Field of the Invention
The present invention relates generally to audio components primarily intended for use in a motor vehicle, and more particularly to a mounting means for attaching the front cover of an audio component to the housing surrounding it.
2. Description of the Related Art
Audio components such as a radio, cassette player or compact disc player, or a combination of these components, has become a standard feature on a motor vehicle. Typically, the front cover is made from a plastic material and the housing protecting the actual circuitry, is made from metal. The housing is essentially a box enclosed on all sides and open in the front. The front cover fits over the front opening, and may be held in place with fasteners. Another means of holding the front cover in place is a formed metal cover that attaches to the housing and is held by tabs integral with the housing that bend over the adjoining part. However, this does not always provide a tight fit between the front cover and the housing, resulting in undesirable noises stemming from the operation of the vehicle, especially over bumpy roads. The present invention uses specially formed tabs integral with the housing to create an interference fit by rigidly holding the front cover onto the housing and preventing buzzes and rattles during vehicle operation.

Mounting assembly for automotive audio components


Embodiments of the present invention provide a method, a computer program product, and a system for generating a haptic signal representing a fabric composition. Embodiments of the present invention can be used to generate a haptic signal that is based on a user selection. For example, embodiments of the present invention can combine characteristic signals corresponding to a plurality of textiles to generate the haptic signal for output to a haptic device. Embodiments of the present invention can be used to recommend similar fabric compositions based upon similarity between a characteristic signal of a fabric composition and the haptic signal.

The present invention relates generally to the field of augmented reality, and more particularly to haptic technology.
Online shopping for fashion has increased in popularity in recent times. Digital transmissions of photographs and digital representations of clothing through the Internet allows shoppers to browse clothing and apparel in the comfort of their homes. Current online shopping allows for a user to virtually try, mix, and match various clothing and apparel in order to appreciate and better decide for an online purchase. Additionally, haptic technology has been developed such that a haptic device gives a user a sense of touch with computer-generated environments, so that when a user interacts with a virtual object, the virtual object seems to be real and tangible. Various forms of haptic devices use vibrations or force feedback to alert a user of a virtual or otherwise unseen object, such as user control vibrations for an aircraft when the aircraft is approaching a stall, force feedback for excavators when excavating mixed material such as rocks embedded in silt or clay, or a combination of force feedback and vibration for a gaming controller when a user interacts with the virtual world of a game. Recent developments in haptic technology include reverse electrovibration where an oscillating low-level electric signal passes between the skin of a user and a conductive surface covered with a thin insulating layer, wherein the oscillating electric signal corresponds to texture variations of an object, resulting in the user perceiving the texture of a simulated object.

Simulating tactile information for haptic technology

International Business Machines Corporation


According to the present invention, polytrimethylene terephthalate fiber is provided, which is high in toughness, uniform in fiber size and excellent in dyeing uniformity, whereby it is extremely suitable for a clothing use.

The present invention relates to a polytrimethylene terephthalate fiber (hereinafter referred to as PTT fiber), which is a kind of polyester fiber, and a method for producing the same. Specifically, it relates to a so-called two-step method for producing PTT fiber wherein polytrimethylene terephthalate is melt-spun and once taken up as an undrawn fiber after which it is drawn to be the PTT fiber and the PTT fiber thus obtained has a high uniformity suitable for a clothing use. More specifically, it relates an atmospheric condition and a time period for maintaining the undrawn fiber in the above-mentioned method for producing the same.
Polyester fibers mainly composed of polyethylene terephthalate have widely been produced, all over the world, as synthetic fibers most suitable for clothing use, and the polyester fiber industry has already developed into a major industrial field.
On the other hand, PTT fiber has long been studied, but it has not yet reached full-scale industrial production because of a high price of trimethylene glycol which is one of raw materials thereof in the prior art. In this regard, a method has recently been invented, for producing trimethylene glycol at a low cost, whereby there is a possibility of industrialization.
PTT fiber is expected to be an epoch-making fiber having the advantages of polyester fiber and nylon fiber, and the application thereof has been studied for clothing use or carpet use in which the advantages thereof are desirable.
PTT fiber has long been known in the prior art and, for example, from Japanese Unexamined Patent Publications (Kokai) No. 52-5320 (A), No. 52-8123 (B), No. 52-8124 (C), NO. 58-104216 (D), J. Polymer Science: Polymer Physics Edition Vol., 14, 263 to 274 (1976) (E), and Chemical Fibers International Vol., 45, April (1995) 110 to 111 (F).
In these prior arts, PTT fiber is produced by a so-called two-step method and there is the following description in (D) which is technically similar to the present invention:
xe2x80x9cSince PTT undrawn fiber produced by an ordinary production method, i.e., at a spinning rate of lower than 2000 m/min has extremely low degrees of orientation and crystallization and a glass transition point as low as 35xc2x0 C., the properties thereof very quickly change with time whereby it is difficult to obtain PTT fiber having favorable properties because of the generation of fluff or neps during a drawing process.xe2x80x9d
A method is proposed in (D) as a technique for avoiding this problem, wherein a spinning rate is 2000 m/min or higher, preferably 2500 m/min or higher to develop the degrees of orientation and crystallization and a drawing temperature is maintained in a range from 35 to 80xc2x0 C. Also, there is an example in (D) wherein an undrawn fiber obtained at a spinning rate of 3,500 m/min is drawn after being left for 24 hours under the condition of 20xc2x0 C. and 60% RH.
Although there is a description in (D) that the structure and physical properties of the undrawn fiber spun at a spinning rate lower than 2000 m/min significantly vary with time at a room temperature to directly disturb the drawing stability, there are neither descriptions nor suggestions of countermeasure for avoiding adverse effects caused by such a variation with time of the undrawn fiber obtained at a spinning rate of lower than 2000 m/min, not to speak of concrete means for suppressing such variation with time within a minimum limit to obtain a high quality fiber while maintaining a favorable drawing stability.
From the description of Examples in (D), PTT fiber resulted from the method of (D) has a toughness of 18 (cN/dtex)%xc2xd or less, from which it will be apparent that the mechanical property is poorer.
In a comparative example disclosed in (D), a description is seen in that an undrawn fiber spun at a spinning rate of 1200 m/min was left in the atmosphere at 20xc2x0 C. and 60% RH, and thereafter drawn to be a drawn fiber having a toughness of as low as 18 (cN/dtex)%xc2xd, however, there is no description on the variation value of fiber size (U%) or the periodic fluctuation thereof.
As a result of studies according to the present inventors, it was found that when PTT fiber is produced by the two-step method wherein a spinning rate is 1900 m/min or less, a shrinkage of the resultant undrawn fiber varies with atmospheric temperature and time as shown in FIGS. 1 and 2. It was also found that if the variation of shrinkage with time is large, an undrawn fiber package transforms from a normal shape as shown in FIG. 3A to an abnormal shape as shown in FIG. 3B due to the shrinkage as the time lapses, and lengths of the undrawn fiber in the package are partially adhered to each other to disturb the smooth unwinding of the undrawn fiber, which results in the large fluctuation of unwinding tension and the generation of many yarn breakages or single-filament breakages to worsen the drawing stability. Note that, in FIGS. 3A and 3B, reference numeral 1 denotes the undrawn fiber and 2 denotes a bobbin for taking up the undrawn yarn.
Also, it was apparent that the drawn yarn obtained from the undrawn fiber wound in the package transformed due to the variation of shrinkage with time generally has a large variation value of fiber size, i.e., U%, and the periodic fluctuation thereof corresponding to a traverse width of a take-up winder for the undrawn fiber (2 to 5 m as converted to the drawn fiber) or integral times thereof (see FIGS. 4A and 5A). A knit or woven fabric made of such a drawn fiber having the large U% and the periodic fluctuation of fiber size is in general unevenly dyed to exhibit a periodic dyeing speck or luster which is apparently unsuitable for a clothing use in which the uniformity is the most important property.
Generally speaking, in the industrial production of synthetic fiber by the two-step method, maximally three or four days are required for completing the drawing after the undrawn fiber has been taken up, whereby influence of the variation in shrinkage with time is substantially inevitable. Accordingly, the industrial production of PTT fiber suitable for the clothing use is impossible under the condition wherein the variation in shrinkage with time is significant as in the above manner.
An object of the present invention is to provide a high-quality PTT fiber suitable for clothing use obtained by a two-step method, which can be drawn in a stable manner (to result in a high yield), high in toughness and low in variation of fiber size, particularly in periodic fluctuation of fiber size, preferable for an apparel, excellent in quality, and a method for industrially producing such PTT fiber. A problem to be solved by the present invention is to suppress the shrinkage of the undrawn fiber with time as much as possible, to reduce the fluctuation of unwinding tension of the undrawn fiber and to eliminate the adverse effect on the drawing stability of the undrawn fiber and on the quality of the drawn fiber.
As a result of diligent study, the present inventors found the relationship between the atmospheric condition (temperature and relative humidity) in which PTT undrawn fiber is retained and the shrinkage variation of the undrawn fiber with time as well as the relationship between the atmospheric condition and the drawing stability or the quality of the drawn fiber. The present invention has completed based on such a knowledge.
That is, a first aspect of the present invention is a twisted or non-twisted PTT fiber high in uniformity, having an intrinsic viscosity in a range from 0.7 to 1.3, composed of 95 mol % or more of repeated units of trimethylene terephthalate and 5 mol % or less of repeated units of other ester, characterized in that a toughness of the fiber is 19 (cN/dtex)%xc2xd or more and a variation value of fiber size (U%) during the continuous measurement of the fiber size by an evenness tester is 1.5 or less as well as the fiber exhibits either one of characteristics defined by the following requisites (1), (2) and (3);
(1) a periodic variation on the smaller fiber size side at an interval of 10 m or less exists in an evenness tester chart, and a magnitude of the variation is 2% or less of an average fineness,
(2) while the existence of the periodic variation on the smaller fiber size side at an interval of 10 m or less is not discernible from the evenness tester chart, a periodic variation at an interval of 10 m or less exists in a diagram for analyzing the period of fiber size variation, and
(3) no periodic variation on the smaller fiber size side at an interval of 10 m or less is discernible from the evenness tester chart, and no periodic variation at an interval of 10 m or less exists in the diagram for analyzing the period of fiber size variation.
(Note the toughness is calculated from the equation of strength at breakxc3x97elongation at breakxc2xd (cN/dtex)%xc2xd, and a length of fiber to be measured by the evenness tester is 250 m.)
A second aspect of the present invention is a method for producing a fiber from PTT having an intrinsic viscosity in a range from 0.7 to 1.3, composed of 95 mol % or more of repeated units of trimethylene terephthalate and 5 mol % or less of those of other ester by a two-step method wherein an undrawn fiber is once taken up in a spinning process as a package form at a take-up rate of 1900 m/min or less and then drawn in a drawing process, characterized in that the undrawn fiber is taken up at a take-up tension in a range from 0.04 to 0.12 cN/dtex, and retained in an environmental atmosphere having a temperature in a range from 10 to 25xc2x0 C. and a relative humidity in a range from 75 to 100% during a winding process, a storage process and a drawing process, and in that the drawing of the undrawn fiber is completed within 100 hours after the undrawn fiber has been taken up.
The present invention will be described in more detail below.
The present invention is a method for producing a fiber from PTT having an intrinsic viscosity in a range from 0.7 to 1.3, composed of 95 mol % or more of repeated units of trimethylene terephthalate and 5 mol % or less of those of other ester by a two-step method wherein an undrawn fiber is once taken up in a spinning process as a package form at a take-up rate of 1900 m/min or less and then drawn in a drawing process, and a twisted or non-twisted PTT filament fiber obtained by the above method.
In general, the drawing operation in the two-step method is carried out by a so-called draw twister shown in FIG. 7 or a draw winder shown in FIG. 8, and a drawn fiber is wound as a pirn (shown in FIG. 9) in the former or as a cheese (shown in FIG. 10) in the latter. Generally speaking, the fiber wound in the pirn is twisted, while the fiber wound in the cheese is non-twisted. In FIGS. 7 and 8, reference numeral 15 denotes an undrawn package, 16 a supply roll, 17 a hot plate, 18 a draw roll, 19 a pirn and 20 a cheese. Also, in FIG. 9, reference numerals 21 and 22 denote a bobbin and a drawn fiber, respectively. In FIG. 10, reference numerals 23 and 24 denote a paper tube and a drawn fiber, respectively.
In the first aspect of the present invention, the toughness is 19 (cN/dtex)%xc2xd or more. If the toughness is less than 19 (cN/dtex)%xc2xd, mechanical properties such as a tearing strength of a knit or woven fabric obtained by processing the PTT fiber becomes too inferior to be used for clothing. A preferable value of the toughness is 21 (cN/dtex)%xc2xd or more. In this regard, the toughness of polyethylene terephthalate fiber for general clothing use is approximately 24 (cN/dtex)%xc2xd.
In the first aspect of the present invention, a variation value of fiber size (U%) during the continuous measurement of the fiber size by an evenness tester is 1.5% or less. If the U% exceeds 1.5%, physical properties of the fiber become uneven to result in a streaky or irregularly dyed knit or woven fabric. U% is preferably 1.2% or less, more preferably 1.0% or less.
It is thought that the undrawn fiber obtained under conditions wherein a package of the undrawn fiber is significantly transformed due to the shrinkage with time has a large variation in size of undrawn fiber to worsen the U%.
According to the first aspect of the present invention, there is a periodic variation on a smaller fiber size side at an interval of 10 m or less on a chart obtained by the continuous measurement of a fiber size by an evenness tester, and a magnitude of the variation is 2% or less relative to an average fiber size. This corresponds to the above-mentioned requisite (1).
The confirmation of whether or not the periodicity exists in the variation of fiber size may be possible by directly reading a chart of the continuous measurement of fiber size (Diagram Mass) or through an analysis of the periodic variation in fiber size (Spectrogram Mass) described later. In the latter, if there is a peak in CV value representing a variance of the fiber size (shown in a vertical axis of the analysis diagram) exceeding approximately 0.2% between 1 m and 10 m of a length of period (shown in a horizontal axis of the analysis diagram), it is said that the periodicity exists in the variation of fiber size.
The periodic variation on the smaller fiber size side is a variation corresponding to downward whisker-like signals generating at an equal interval on a continuous measurement chart of fiber size shown in FIG. 4A. A fact that the signals generated at an equal interval are observed at the equal interval means that the fluctuation of fiber size causing the signals periodically occurs, and the existence of a downward signal means that a fiber size (a fineness of fiber) at that point as seen in the lengthwise direction of the fiber varies to a smaller side. A ratio of the periodic variation on a smaller fiber size side relative to the average fiber size is directly readable from the chart. If this ratio exceeds 2%, a knit or woven fabric suitable for a clothing use is not obtainable from this fiber even though the U% is 1.5% or less, because the dyeing speck and the unevenness of luster become significant due to this periodic variation of fiber size.
An interval of the period variation of fiber size substantially corresponds to a product of one traverse stroke or two between opposite ends of an undrawn fiber package and a draw ratio. It is surmised that a length of undrawn fiber existing at opposite ends or one end of the package is drawn due to the unwinding resistance to cause the periodic variation of fiber size on the smaller fiber size side. In the two-step method, the interval of the periodic variation of fiber size is determined by a traverse stroke, a winding angle and a draw ratio of a winder for the undrawn fiber and, in general, is 10 m or less.
When the periodic variation of fiber size on the smaller fiber size side becomes small, the downward signals generated at the equal pitch are not discernible on the continuous measurement chart of fiber size as shown in FIG. 4B. However, in a period analysis diagram (shown in FIG. 5B) corresponding to FIG. 4B, there are signals representing the existence of the periodic variation. The above-mentioned requisite (2) defines such a phenomenon that signals are not discernible in the chart but are represented in the period analysis diagram. In the diagram shown in FIG. 5B, four signals, i.e., those projecting like mountains exist in an area of the horizontal axis shorter than 10 m. This state, wherein one mountain-like signal, or more, is visible, is a state wherein the periodic variation exists in fiber size on the period analysis diagram as defined in the requisite (2). In this regard, according to the period analysis, it could not be determined whether or not the signals belong to the smaller fiber size side or the larger fiber size side. The range satisfying the requisite (2) is a favorable range of the present invention.
If the periodic variation of fiber size becomes further smaller, no mountain-like signal is visible even in the periodic analysis diagram. This state is one showing the characteristic of the requisite (3). That is, the range satisfying the requisite (3) is a more favorable range of the present invention.
In the second aspect of the present invention, a winding tension of the undrawn fiber in the spinning process is 0.04 to 0.12 cN/dtex. If the winding tension is within this range, no significant transformation of the package results even though the undrawn fiber slightly contracts with time. If the atmospheric temperature is retained at a relatively high value within a range defined by the present invention, the winding tension is preferably set at a relatively low level. On the other hand, if the atmospheric temperature is retained at a relatively low value, the winding tension is preferably set at a relatively high level.
If the winding tension is less than 0.04 cN/dtex, it becomes difficult to wind up the undrawn fiber continuously because the fiber runs unstably. If the winding tension exceeds 0.12 cN/dtex, the transformation of the package is not avoidable due to the shrinkage of the undrawn fiber with time even though the environmental atmospheric temperature is retained in a range from 10 to 25xc2x0 C.
According to the second aspect of the present invention, the winding, storage and drawing processes of the undrawn fiber are retained in the environmental atmosphere having a temperature in a range from 10 to 25xc2x0 C. and a relative humidity in a range from 75 to 100%.
If the atmospheric temperature is lower than 10xc2x0 C., the shrinkage of the undrawn fiber with time becomes extremely small, but the cost necessary for the temperature control increases as well as the working efficiency lowers due to the cold. On the contrary, if the atmospheric temperature exceeds 25xc2x0 C., the shrinkage of the undrawn fiber with time becomes so large that the transformation of the package is not avoidable even though the winding tension is lowered to 0.04 cN/dtex.
A favorable range of the atmospheric temperature is from 15 to 22xc2x0 C. in view of the transformation of the undrawn fiber package, the cost necessary for temperature control and the working efficiency.
In the second aspect of the present invention, the relative humidity of the atmosphere in which the undrawn fiber is retained during the respective processes is in a range from 75 to 100%. If the relative humidity is less than 75%, water imparted together with a finishing agent to the undrawn fiber package is promptly evaporated solely at the opposite ends of the package to lower the moisture content of the undrawn fiber in these portions, which results in the generation of much fluff in the drawn fiber as well as the rise in U% of the fiber exceeding 1.5% after being drawn whereby the unevenness or the streaky defect are significant in the dyed fabric. A more favorable range of the relative humidity is from 80 to 95%.
According to the second aspect of the present invention, it is necessary to complete the drawing of the undrawn fiber within 100 hours after the winding. The time from the initiation of the winding process to the completion of the drawing process, that is, a period from an instant at which a leading end of the undrawn fiber is wound at the innermost layer of the undrawn fiber package to an instant at which the leading end is drawn, is generally referred to as a lag time. The lag time must be within 100 hours in the present invention.
If the lag time exceeds 100 hours, water imparted to the undrawn fiber together with the finishing agent is partly evaporated to make the water content of the respective portions of the package unequal, while the shrinkage of the undrawn fiber with time is small to minimize the package transformation, whereby the U% of the drawn fiber becomes larger than 1.5% to result in the dyeing speck (the dyeing grade is lowered below a reject level). The lag time is preferably within 75 hours, more preferably within 50 hours.
A detailed description will be given for PTT polymer according to the present invention.
PTT according to the present invention is composed of 95 mol % or more of repeated units of trimethylene terephthalate and 5 mol % or less of those of other ester.
That is, the PTT according to the present invention is a copolymer composed of PTT homopolymer and other ester units of 5 mol % or less. A representative of the copolymer components is as follows:
An acidic component includes dicarbonic acid having sulfonic group, represented by 5-sodium sulfoisophthalic acid, and metallic salts thereof; aromatic dicarbonic acid represented by isophthalic acid; aliphatic dicarbonic acid represented by adipic acid, while a glycolic component includes ethylene glycol, butylene glycol and polyethylene glycol. A plurality of copolymeric components may be contained.
An intrinsic viscosity of PTT according to the present invention is in a range from 0.7 to 1.3. For a clothing use, a preferable range is from 0.8 to 1.1.
PTT according to the present invention may contain additives, such as a residual metal-type catalyst, a heat stabilizer, an antioxidant, a delusterant, a shade adjuster, a flame retardant, an ultraviolet inhibitor or others, which may be contained as copolymerized components.
A known method may be applied to produce PTT according to the present invention. In general, after being polymerized in a molten state, an intrinsic viscosity of the polymer may be further increased through the solid-phase polymerization.
In the production of PTT fiber according to the present invention, for example, a process shown in FIGS. 6 and 7 may be adopted.
In FIG. 6, PTT pellets dried in a dryer 3 to have a moisture content of 30 ppm or less is supplied to an extruder 4 set at a temperature in a range from 255 to 265xc2x0 C. and melted therein. The molten PTT is fed through a bend 5 to a spin head 6 set at a temperature in a range from 250 to 265xc2x0 C. and metered by a gear pump. Thereafter, PTT is extruded into a spinning chamber as a multifilament 9 through a spinneret 8 having a plurality of orifices and mounted to a spin pack 7.
An optimum temperature is selected from the above range as that of the extruder or the spin head in accordance with an intrinsic viscosity and a shape of the PTT pellet.
The PTT multifilament extruded into the spinning chamber is thinned by godet rolls 12, 13 rotating at predetermined speeds, while being quenched by a cooling air 10 to a room temperature, and solidified to be an undrawn fiber having a predetermined fiber size. Prior to being in contact with the godet roll 12, the undrawn fiber is imparted with a finishing agent by a finishing agent applicator 11. After departing from the godet roll 13, the undrawn fiber is taken up by a winder 14 to be an undrawn fiber package. A winding speed of the undrawn fiber is preferably in a range from 1000 to 1900 m/min.
In this process, an environmental atmosphere surrounding the godet rolls 12, 13 and the winder is maintained at a temperature in a range from 10 to 25xc2x0 C. and a relative humidity in a range from 75 to 100%. Also, when it is necessary to temporarily store the undrawn fiber package thus formed prior to being delivered to a drawing process, the package is stored in the atmosphere with the above-mentioned conditions.
A winding tension of the undrawn fiber is adjustable by changing the winding speed; i.e., a ratio of the peripheral speed of the undrawn fiber package to that of the godet roll 13 during the winding operation.
The finishing agent is of an aqueous emulsion type which is safe for the working environment. A concentration of the finishing agent is preferably in a range from 10 to 30 wt %. When the aqueous emulsion type finishing agent is imparted, the undrawn fiber after being wound contains an amount of water in accordance with the concentration and the adhesion degree of the finishing agent. The moisture content is generally in a range from 3 to 5 wt %.
The undrawn fiber package is then delivered to a drawing process in which it is drawn by the draw twister as shown in FIG. 7. The undrawn fiber package 15 is retained in the atmosphere of the draw twister at a temperature in a range from 10 to 25xc2x0 C. and a relative humidity in a range from 75 to 100% while being drawn. In the draw twister, the undrawn fiber 15 is first heated on the supply roll 16 having a temperature in a range from 45 to 65xc2x0 C. and drawn by using a ratio of the peripheral speed of the draw roll 18 to that of the supply roll 16 to have a predetermined fiber size. The fiber runs during or after the drawing while being in contact with the hot plate 17 set at a temperature in a range from 100 to 150xc2x0 C. to be subjected to a stretch heat treatment. The fiber exiting the draw roll is twisted by a spindle and wound to form the pirn 19.
In the above process, the ratio of the peripheral speed of the draw roll 18 to that of the supply roll 16, that is, the draw ratio, and the hot plate temperature are preferably set so that the drawing tension is approximately 0.35 cN/dtex.

Abstract: Polytrimethylene terephthalate fiber according to the present invention can be produced by a two-step method consisting of a low speed spinning process and a drawing process, wherein the winding condition of undrawn fiber, the atmospheric condition under which the undrawn fiber is retained and the time for retaining the undrawn fiber are set to a specific range so that the shrinkage of undrawn fiber with time and the transformation of the undrawn package caused thereby are minimized. Thus, the unwinding tension of the undrawn fiber is maintained constant whereby the drawing is favorably carried out to result in a high quality polytrimethylene terephthalate fiber.


A road marker (10) comprising a body (12) extruded from a non-resilient material is disclosed and claimed. The marker body comprises a sloping wide base (14), a neck (18) and a head (16) and is generally I-shaped in transverse cross section. The cross-sectional area of the neck (18) on line A is less than that of the head (16) and that of base (14) in parallel planes.

THIS invention relates to markers for roads or pavements or so-called cat's eyes.
The road markers known to the applicant suffer from at least one of the following disadvantages. These markers are primarily made by an injection moulding process of a suitable metal or synthetic resinous material which makes them and their moulds relatively expensive. Due to their structure and to ensure stable anchorage in the pavement or road surface, their reflector elements are located too close to the road surface, so that soiling of these elements occur. Furthermore, due to their structure, rocking of the marker occurs upon impact with a vehicle wheel, which causes the marker to become loose in the road structure.
In U.S. Pat. No. 4,127,348 to Roberts there is disclosed a road marker with a complex shape including skirts to protect the reflector elements. The marker body is formed of aluminium as a die casting. This marker suffers from the disadvantage that due to its process of manufacture, it is relatively expensive and time-consuming to produce. Furthermore, the reflector elements are located too close to the road surface and soiling of the rather obscured reflectors can easily take place. Still furthermore, the skirts, in use, entrap dirt which is not readily removed by rain and/or traffic action.
In U.S. Pat. Nos. 4,521,129 and 4,534,763 to Minnesota Mining and Manufacturing Company there are disclosed road markers produced by an extrusion process from a resiliently flexible material. The reflector of the marker comprises a reflective film adhered to a surface of the marker body which, in use, faces oncoming traffic. It is believed that as a result of the deformation of the marker every time it is struck by a wheel of a vehicle, the marker body and/or film will be damaged. The marker is also highly susceptible to damage by vandals. Furthermore, the marker is clearly not suitable for use on roads carrying traffic in opposite directions.


A process for forming a semiconductor device comprises the steps of providing a semiconductor substrate assembly comprising a semiconductor wafer having an active area formed therein, a plurality of transistor gates each having a TEOS cap thereon and a pair of nitride spacers along each gate, a plurality of conductive plugs each contacting the wafer, and a BPSG layer overlying the transistor gates and contacting the active area. A portion of the BPSG layer is etched thereby exposing the TEOS caps. A portion of the BPSG layer remains on the active area after completion of the etch. Subsequently, a portion of the TEOS caps are removed to expose the transistor gates and a titanium silicide layer is formed simultaneously to contact the transistor gates and the plugs. An inventive structure resulting from the inventive process is also described.

This invention relates to the field of semiconductor assembly, and more particularly to a process for forming conductive structures having enhanced conductivity, and the in-process structure resulting from the process.
Structures such as polycrystalline silicon (poly) plugs, interconnects, and transistor gates are commonly formed during the manufacture of semiconductor devices such as microprocessors, memory devices, and logic devices. To manufacture a plug, for example, a masked dielectric layer is formed over an underlying substrate assembly and an etch is completed to form a hole in the dielectric which exposes the underlying structure in the area where contact is to be made. A blanket poly layer is deposited over the dielectric layer which fills the hole in the dielectric layer and contacts the underlying structure. The poly is then removed from a planar surface of the dielectric, typically using a chemical mechanical polishing (CMP) process which leaves the plug formed within the dielectric layer. Interconnects and gates are typically formed by depositing a blanket layer of poly over a semiconductor substrate assembly, then masking and etching the layer.
As the sizes of the plugs and line widths decrease with improving manufacturing technology, the doped poly structure may provide excessive resistance and insufficient conductance. To reduce the resistance of a structure, a silicide layer is often formed underneath the plug or over the top of the plug, gate or interconnect. To form the silicide layer to enhance plug conductivity the silicide layer can be formed before formation of the plug. A titanium chemical vapor deposition (CVD) process results in titanium reacting with the exposed silicon wafer to form titanium silicide. An unreacted titanium metal layer will also form over any exposed dielectric layer which is then stripped. After stripping the unreacted titanium, the poly plugs are formed over the silicide layer as described above.
A silicide layer can also be formed over the plug, transistor gate or other interconnect after forming the blanket poly layer which forms the gate or interconnect. During a titanium CVD process similar to that described above for forming silicide under the plug, the titanium reacts with the polysilicon to form silicide on top of the poly layer, then the poly is masked and etched to define the line or plug.
U.S. Pat. No. 5,381,302 by Sandhu et al. and U.S. Pat. No. 5,198,384 by Dennison, each assigned to Micron Technology, Inc. and incorporated herein by reference in their entirety, describe a process for forming a silicide layer over a poly plug.
While the silicide layer interposed between the silicon wafer and the poly plug provides decreased resistance and increased conductance it can also provide a path for leakage between an adjacent transistor channel region and an active area, thereby increasing junction leakage. A process and structure which provides improved conductance and reduced resistance and which does not increase junction leakage would be desirable. It would be further desirable to provide a plug having a maximized amount of silicide formed thereon.
The present invention provides a new process and structure having fewer problems associated with the formation of silicided polycrystalline silicon plugs, particularly problems resulting in excessive transistor junction leakage. In accordance with one embodiment of the invention, a semiconductor substrate assembly is provided which comprises a semiconductor wafer, a plurality of transistor gates, and a plurality of conductive plugs which contact the wafer. A silicide layer is formed which simultaneously forms to contact the plurality of gates and the plurality of plugs. In another embodiment, a plug is formed which comprises silicide on the sidewalls, thereby maximizing the amount of the desirable silicide to minimize resistance.
Objects and advantages will become apparent to those skilled in the art from the following detailed description read in conjunction with the appended claims and the drawings attached hereto.

Low resistance semiconductor process and structures


The present invention provides a GPS receiver comprising sampling circuitry adapted to perform IF-to-baseband conversion. In general, the GPS receiver includes downconversion circuitry that uses a first synthesizer output signal to reduce an amplified GPS input signal to an intermediate frequency signal, and sampling circuitry that receives the intermediate frequency signal and produces a baseband digital representation of the amplified GPS input signal. The sampling circuitry performs IF-to-baseband conversion by using a sampling rate equal to the frequency of a second synthesizer output signal, where the sampling rate is selected such that only an alias of the IF signal having the appropriate baseband frequency is digitized.

The global positioning system (GPS) is based on an earth-orbiting constellation of twenty-four satellite vehicles each broadcasting its precise location and ranging information. From any location on or near the earth, a GPS receiver with an unobstructed view of the sky should be able to track at least four satellite vehicles thereby being able to calculate the receiver's precise latitude, longitude, and elevation. Each satellite vehicle constantly transmits two signals, generally referred to as L1 and L2. The L1 signal from a satellite vehicle contains a unique pseudo-random noise code ranging signal with a chipping frequency of 1.023 MHz, system data with a bitrate frequency of 50 Hz, and an encrypted precise-code (y-code) with a chipping frequency of 10.23 MHz all being modulated onto a carrier frequency of 1575.42 MHz. The L2 signal consists of the system data and y-code being modulated onto a carrier frequency of 1227.60 MHz. In order to calculate a three-dimensional location, a receiver must determine the distance from itself to at least four satellite vehicles. This is accomplished by first determining the location of at least four satellite vehicles using ephemeris data received from the satellites. Once the locations of the satellites have been determined, the distance from the receiver to each of the satellites is calculated based upon an estimate of the receiver's position. The measurement of the distance from the receiver to a satellite is based on the amount of time that elapsed between the transmission of a ranging signal from each satellite vehicle and the reception of that chip symbol by the receiver. In particular, the estimated position of the receiver is then corrected based upon a time epoch associated with the received ranging signal.
The accuracy of a GPS receiver depends on the accuracy with which the receiver is capable of measuring the time that has elapsed between the broadcast of the range information by a satellite vehicle and the reception of the information by the receiver. There are several factors that reduce the accuracy of the time measurement in the receiver design, including the sampling bandwidth of the receiver, the number of sampling bits, errors caused by internally generated noise, and external interference. Additional system factors that cause reduction of accuracy include errors in the ephemeris data (location of the satellite), errors caused by delays due to the ionosphere and troposphere, and multipath errors caused by reflected signals entering the receiver antenna.
In order to obtain the precise location of the receiver, a received GPS signal must be converted from an RF signal to a baseband signal before the GPS information can be extracted from the received GPS signal. In the present state of the art, a received GPS signal is downconverted to an IF signal, and the IF signal is converted to baseband using filtering circuitry such as SAW filters, which are not compatible for integration onto a semiconductor die with the other components of the GPS receiver.

Alias sampling for IF-to-baseband conversion in a GPS receiver