11 resultados para custom

em Chinese Academy of Sciences Institutional Repositories Grid Portal


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Huazhong Univ Sci & Technol, Natl Tech Univ Ukraine, Huazhong Normal Univ, Harbin Inst Technol, IEEE Ukraine Sect, I& M/CI Joint Chapter

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In the sinusoidal phase modulating interferometer technique, the high-speed CCD is necessary to detect the interference signals. The reason of ordinary CCD's low frame rate was analyzed, and a novel high-speed image sensing technique with adjustable frame rate based on ail ordinary CCD was proposed. And the principle of the image sensor was analyzed. When the maximum frequency and channel bandwidth were constant, a custom high-speed sensor was designed by using the ordinary CCD under the control of the special driving circuit. The frame rate of the ordinary CCD has been enhanced by controlling the number of pixels of every frame; therefore, the ordinary of CCD can be used as the high frame rate image sensor with small amount of pixels. The multi-output high-speed image sensor has the deficiencies of low accuracy, and high cost, while the high-speed image senor with small number of pixels by using this technique can overcome theses faults. The light intensity varying with time was measured by using the image sensor. The frame rate was LIP to 1600 frame per second (f/s), and the size of every frame and the frame rate were adjustable. The correlation coefficient between the measurement result and the standard values were higher than 0.98026, and the relative error was lower than 0.53%. The experimental results show that this sensor is fit to the measurements of sinusoidal phase modulating interferometer technique. (c) 2007 Elsevier GmbH. All rights reserved.

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Polyfluorinated and perfluorinated compounds (PFCs) are used in numerous commercial products and have been ubiquitously detected in the environment as well as in the blood of humans and wildlife. To assess the combined effects caused by PFCs in mixtures, gene expression profiles were generated using a custom cDNA microarray to detect changes in primary cultured hepatocytes of rare minnows exposed to six individual PFCs (perfluorooctanoic acid, perfluorononanoic acid, perfluorodecanoic acid, perfluorododecanoic acid, perfluorooctane sulfonate, and 8:2 fluorotelomer alcohol) and four formulations of the PFCs mixtures. Mixtures as well as individual compounds consistently regulated a particular gene set, which suggests that these conserved genes may play a central role in the toxicity mediated by PFCs. Specifically, a number of genes regulated by the mixtures were identified in this study, which were not affected by exposure to any single component. These genes are implicated in multiple biological functions and processes, including fatty acid metabolism and transport, xenobiotic metabolism, immune responses, and oxidative stress. More than 80% of the altered genes in the PFOA- and PFOS-dominant mixture groups were of the same gene set, while the gene expression profiles from single PFOA and PFOS exposures were not as similar. This work contributes to the development of toxicogenomic approaches in combined toxicity assessment and allows for comprehensive insights into the combined action of PFCs mixtures in multiple environmental matrices. (C) 2009 Elsevier B.V. All rights reserved.

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This paper presents a behavior model for PLL Frequency Synthesizer. All the noise sources are modeled with noise voltages or currents in time-domain. An accurate VCO noise model is introduced, including both thermal noise and 1/f noise. The behavioral model can be co-simulated with transistor level circuits with fast speed and provides more accurate phase noise and spurs prediction. Comparison shows that simulation results match very well with measurement results.

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An ultra low power non-volatile memory is designed in a standard CMOS process for passive RFID tags. The memory can operate in a new low power operating scheme under a wide supply voltage and clock frequency range. In the charge pump circuit the threshold voltage effect of the switch transistor is almost eliminated and the pumping efficiency of the circuit is improved. An ultra low power 192-bit memory with a register array is implemented in a 0.18 mu M standard CMOS process. The measured results indicate that, for the supply voltage of 1.2 volts and the clock frequency of 780KHz, the current consumption of the memory is 1.8 mu A (3.6 mu A) at the read (write) rate of 1.3Mb/s (0.8Kb/s).

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现代计算机在体系结构和应用场景复杂性的增长使得程序性能的增长、保持程序性能的可移植性以及程序开发效率的提升越来越困难,程序自动调优(auto-tuning) 是解决此问题的一个可行途径。本文研究一种通过为循环嵌套自动定制循环优化序列来进行程序自动调优的方法,提高了被编译程序的性能和可移植性,也有助于提升开发效率。 在综述相关工作的基础上,本文首先分析了循环优化序列自动定制研究需要解决的几个关键问题:循环优化的形式化描述及实施、循环优化序列的性能评估、循环优化序列的自动定制方法以及相关的原型工具。本文围绕这几个问题进行研究。 本文采用了Polyhedron模型来描述循环优化,并基于此实施了循环优化的仿射变换。这一工作基于URUK/WRaP-IT开源软件包实现,并作出了若干重要改进。借助Polyhedron模型,本文还给出了部分常见循环优化之间的使能(enable)关系。循环优化之间的相互影响较为普遍,一个循环优化的执行可能会破坏后续优化的实施条件,也可能不破坏甚至创造相应条件。这一关系可以用于过滤循环优化序列定制过程中产生的无效序列从而加快定制速度。本文分析了两个循环优化以先后次序执行时,循环嵌套内所有依赖距离向量均得以保持的条件,给出了它们之间的使能关系。并且给出了使能关系在Polyhedron模型下的计算方法,以及在序列搜索过程中通过维护依赖距离向量状态计算使能关系的方法。 对于循环优化序列性能评估方法,本文采用了高速缓存失效率简化方程(CMES方程)以动态给出循环嵌套中的高速缓存失效率数据,提出了LoopCost模型以静态分析方式发现循环嵌套中对性能影响最大的维度,这两种评估方法分别适用于不同的序列定制方法。 给出了Cache 失效率简化方程(CMES, Cache Miss Equation Simplified)在Polyhedron 模型下的求解方法。CMES方程可在编译时给出循环嵌套中的Cache失效率数据,不需要实际编译运行目标程序,从而避免相关文献中使用运行时信息来评价优化序列带来的巨大编译开销。给出了CMES方程各个参数从循环嵌套的Polyhedron模型中提取的方法,并给出了具体计算过程。 提出了一种可发现循环嵌套中对性能影响最大维度的循环优化性能评估模型LoopCost。相关文献中所使用的性能评估模型可给出一个循环嵌套的整体性能,但无法给出哪个维度对其性能影响最大;而大多数循环优化实际上是对某一个维度所做的变换,因此这些评估模型不能直接指导优化序列的搜索,只能是在一个迭代过程中提供性能信息。LoopCost模型基于数据依赖关系对一个循环嵌套估算出其每个维度使用的cache行数,作为衡量局部性优劣的指标,适用于紧嵌套循环和非紧嵌套循环,并且其复杂度与循环嵌套个数和引用个数成线性关系。通过对SPEC CPU 2006中5,703个循环嵌套的实验,LoopCost模型对其中98.3%的循环嵌套都能给出正确的性能评估数据。 对于循环优化序列自动定制方法,本文首先提出了一种基于CMES方程的Custom方法,使用迭代方式搜索可行优化序列;为了进一步提升优化效率,又提出了一种基于LoopCost模型的快速定制方法FastCustomCustom方法使用CMES方程评估优化序列,使用遗传算法作为序列搜索方法。在遗传算法中的各个算子中利用循环优化的enable关系加速搜索速度。该方法可以避免使用运行时刻信息评估性能所带来的巨大编译开销,又可避免相关工作中利用Polyhedron模型中语句实例执行次序矩阵的性质来搜索带来的局限性,适用的循环优化范围广,编译效率高,同时能取得与相关工作基本相当的加速比。 FastCustom方法优化效率高,并且与Custom方法不同,适用于所有场合。它基于LoopCost模型寻找对性能影响最大的维度,并根据一个启发式策略给出一个循环优化序列。该方法编译速度快,优化效果与Custom方法基本相当。与Custom相比,该方法需要给出启发式策略,因此适用的循环优化范围不如Custom,适用于迭代编译无法进行的情形。 对于循环优化序列自动定制原型工具,本文设计并实现了原型工具CPOLO。该工具改进了URUK/WRaP-IT开源软件包,使其能够支持较为复杂的程序;增强了代码重生成的效率;并且实现了本文所提出的优化序列性能评估模型和自动定制方法。 最后,总结了全文并探讨了进一步的工作方向。

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Scan test can be inserted around hard IP cores that have not been designed with DFT approaches. An 18x18 bits Booth Coding-Wallace Tree multiplier has been designed with full custom approach with 0.61 m CMOS technology. When we reuse the multiplier in another chip, scan chain has been inserted around it to increase the fault coverage. After scan insertion, the multiplier needs 4.7% more areas and 24.4% more delay time, while the fault coverage reaches to 95%.

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During the last years FOPI has developed a new ToF system as an upgrade of the existing detector based on Multi-strip Multi-gap Resistive Plate Chambers (MMRPCs). The intention is to increase the charged Kaon identification up to a laboratory momentum of 1 GeV/c and to enhance the azimuthal detector granularity. The new ToF barrel has an active area of 5 m(2) with 2400 individual strips (900 x 1.6 mm(2)) [A. Schuttauf, et al., Nucl. Phys. B 158 (2006) 52] which are read out on both sides by a custom designed electronics [M. Ciobanu, et al., IEEE Trans. Nucl. Sci. NS-54 (4) (2007) 1201; K. Koch, et al., IEEE Trans. Nucl. Sci. NS-52(3) (2005) 745]. To reach the envisaged goal a time resolution of 100 ps is needed, at a flight path of 1-1.3 m. Due to the rare production of the K- at SIS energies the efficiency of the MMRPCs has to be above 95%. We report on measurements with the detectors and electronics from the mass production line. For this purpose we used a proton beam at 2.0 and 1.25 GeV, at rates between 0.1 and 5 kHz/cm(2) to determine the timing, efficiency and rate capability of the MMRPCs

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This work reports on the design and performance evaluation of a miniature direct methanol fuel cell(DMFC)integrated with an electro_osmotic(EO)pump for methanol delivery.Electro-osmotic pumps require minimal parasitic power while boasting no moving parts and simple fuel cell integration.Here ,aneletro-osmotic pump is realized from a commercially available porous glass frit.We characterize a custom-fabricated DMFC with a free convection cathode and coupled to an extennal electro-osmotic pump operated at applied potentials of 4.0,7.0,and 10V.Maximum gross power density of our free convection DMFC(operated at 50°)is 55 mW/cm2 using 4.0 mol/L concentration methanol solution supplied by the EO pump.Experimental results show that electro-osmotic pumps can deliver 2.0,4.0 and 8.0mol/L methanol/water mixtures to DMFCs while utilizing ~5.0% of the fuel cell power.Furthermore ,we discuss pertinent design considerations when using electro-osmotic pumps with DMFCs and areas of further study.

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提出一种基于FPGA的可重构嵌入式微处理器控制系统.在FPGA中嵌入两个NiosⅡ软核,用VHDL语言编写用户自定义组件.在一个由NiosⅡ软核组成的处理器上实现PWM信号生成、编码器信号处理以及多电机同步伺服运算等,在另一个处理器实现机器人任务管理.该控制系统针对微小型爬壁机器人的控制系统设计,不仅具有良好的实时多任务处理能力,而且具有可重构的特点,因而可应用于一类微小型机器人控制系统以提高其设计的灵活性.

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The relationship between the management and the culture was explored from the view of social norm's theory. In concrete terms, the differences of the hierarchical structure of the social norm among the Chinese, the Japanese and the American were studied systematically by using interview, case study, questionnaire survey and the structure equation model, etc. The results were: (1) The basic two types of the social norms of the Chinese, the American and the Japanese were the same: the external control norm and the internal control norm. The basic dimensions of the two types of norms composed of moral principle, value orientation, the law and the rules, and the social custom were consistent among the three countries. Furthermore, the dimensions of social norms were hierarchical because of the functioning of the different culture, which consisted of the hierarchical structure system. (2) Although there were the same dimensions among the three countries, the contents of these dimensions had both the common norms surpassing the specific culture and the particular norms depending on the specific culture. (3) The basic structures of the social norms in China and in Japan were the same: the internal control norms played a main role and the external control norm was auxiliary. On one hand, within the internal norm of the Chinese, the moral principle was the main force while the value orientation was the supplementary; within the external norm, the law and the rules was the main force while the social culture custom was supplementary. On the other hand, the relationship between the external and the internal dimensions of the Japanese turned out to be contrary to those of the Chinese. (4) The structure of the American social norms were different from the Chinese: for the American, the external control norm played a main role while the internal control norm was assistant. Furthermore, the law and the rule was the major aspect while the social costumes was the second in the external control dimension. In addition, the value orientation led the performance style of the American, while the moral principle played the second role in the internal control structure. (5) The social norms related to the management performance were found including work responsibility, organization commitment, meeting making-decision, communication style, work duty and interpersonal conflict by inventory and case study. The mangers from China, Japan and America had significant different views on paying attention to the management norms. In a word, the culture differences of the social norm were the fundamental reason of the management conflict.