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Ron Wilson 《电子设计技术》2009,(3):54-54,56,58-59
Mentor Graphics公司首席验证科学家Harry Foster认为,今天的大多数设计经理要依赖于某种验证覆盖的量度来回答三个重要问题:我在哪里?去哪里?何时到? 相似文献
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Media Impact usually focuses on the practical impact of multimedia research on IT business. Yet given the pervasiveness of multimedia technology in our everyday life, a thorough reflection on the impact of multimedia progress on education and, in particular, multimedia education is overdue. Multimedia teachers at the 2007 ACM Multimedia conference engaged in a panel discussion on the current state and future of multimedia education. In this issue's,Wolfgang Hürst of Utrecht University and his colleagues Gerald Friedland of the International Computer Science Institute, Berkeley, and Lars Knipping of Berlin University of Technology use this panel as an opportunity to argue the need for a dedicated multimedia curriculum in computer science education. 相似文献
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Tim Saxe Brian Faith 《世界电子元器件》2005,(9):27-28
当FPGA作为ASIC(专用集成电路)的廉价替代品首次面市时广受欢迎,FPGA不仅没有掩膜成本,而且易于修改设计,似乎FPGA只需要不断提高容量,就能够取代大部分产量有限的ASIC了。然而,经验表明,小容量FPGA在替代量产定制逻辑时更受青睐。[编者按] 相似文献
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An infinite planar array of controlled elements in the form of overlapped subarrays excited through a multiport circuit is considered. It is analytically shown that the contour element (subarray) pattern with an ideal contour shape corresponding to the absence of backward mutual coupling and, as a consequence, to the 100% element efficiency can be exactly formed at a definite amplitude distribution over the densely arranged small ideal subarray radiators in spite of the fact that each such a radiator in the subarray has low efficiency caused by the presence of backward mutual coupling. If the small ideal radiators are controlled directly (without the multiport circuit), the contour pattern can be formed with 100% array efficiency for any shape of the contour. If the radiators are not ideal, then the efficiency of the array shaping the contour pattern is determined by averaging the mismatch efficiency of the uniformly excited array scanning over the region bounded by the contour pattern. 相似文献
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《Engineering Management Review, IEEE》2006,34(1):60-60
This publication contains reprint articles for which IEEE does not hold copyright. You may purchase this article from the Ask*IEEE Document Delivery Service at http://www.ieee.org/services/askieee/ 相似文献
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Advanced bit manipulation operations are not efficiently supported by commodity word-oriented microprocessors. Programming tricks are typically devised to shorten the long sequence of instructions needed to emulate these complicated bit operations. As these bit manipulation operations are relevant to applications that are becoming increasingly important, we propose direct support for them in microprocessors. In particular, we propose fast bit gather (or parallel extract), bit scatter (or parallel deposit) and bit permutation instructions (including group, butterfly and inverse butterfly). We show that all these instructions can be implemented efficiently using both the fast butterfly and inverse butterfly network datapaths. Specifically, we show that parallel deposit can be mapped onto a butterfly circuit and parallel extract can be mapped onto an inverse butterfly circuit. We define static, dynamic and loop invariant versions of the instructions, with static versions utilizing a much simpler functional unit. We show how a hardware decoder can be implemented for the dynamic and loop-invariant versions to generate, dynamically, the control signals for the butterfly and inverse butterfly datapaths. The simplest functional unit we propose is smaller and faster than an ALU. We also show that these instructions yield significant speedups over a basic RISC architecture for a variety of different application kernels taken from applications domains including bioinformatics, steganography, coding, compression and random number generation. 相似文献
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Faced with multiple electronic devices, service providers, and ISPs, tomorrow's mobile users might find it challenging to identify available services and acquire the rights to use them. The authors tackle this problem, combining the acquisition of role-based credentials with servicediscovery. 相似文献
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高速Internet和视频业务的迅速发展,IP网络流量持续强劲增长,对运营商的骨干传送网络提出了更高的要求,100G光传技术因此应运而生。该技术在码型、复用方式、相干接收和前向纠错(FEC)等关键技术方面都有创新。对于100G传输商用设备,业界一般看好的长距传输码型是采用相干接收的偏振复用正交相移键控(PDM-QPSK),但由于目前模数转换器(ADC)和DSP芯片等处理技术水平的限制,几乎所有高速电信号处理芯片都没有商用解决方案,这是目前的技术攻关重点。近年来实验室和现网实验方兴未艾,预计基于100G的长距传送系统在1~2年后开始部署。 相似文献
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This paper investigates the notion of the probability of bit error (PBE) and its
distribution in chaos-based communication systems; these are seen as being the fundamental
quantities to both the well-known bit error rate (BER) and the new concept in
chaos communications of bit outage rate (BOR). The form of the distribution illustrates
the degree to which bit error rate is a stable representation of performance. Bit outage rate
is another measure of performance which gives practically helpful information about bit error.
For a simple coherent chaos-shift-keying system the distribution of bit error probability
is derived exactly, and theoretically exact formulas for the bit outage rate and bit error rate
are presented. Two specific cases are developed to obtain useful qualitative and quantitative
information. The cases concern independent Gaussian spreading, as a lower benchmark and
logistic map spreading, as typical of effective chaotic spreading. Comparisons are obtained
between these spreading distributions and between different extents of their spreading,
calibrated against per bit signal to noise ratio. A general conclusion is that bit outage and
bit error rates are complementary measures of performance. 相似文献
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Dipan Patel 《电子产品世界》2003,(18):51-52
在设计高性能电子系统时,工程师都明白进行器件保护是非常重要的问题,既要保护其免受干扰又要保护敏感电子器件不被损坏。随着人类越来越依赖电子系统,保护措施对于系统可靠性和使用寿命的保证变得至关重要。敏感且昂贵的电子系统的应用环境也大大拓展了。长期以来,电子系统已经被广泛用于从舰船技术到食品生产设备等几乎一切领域之中,而近年来无线通信设备的普及是电子系统应用扩展过程中的最新进展,甚至包括刮胡刀和牙刷在内的消费产品也需要保护其中的敏感元器件。然而,工程师发现的问题是,对于设备外壳(或机壳)而言,既需要阻止或防止外… 相似文献
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本文对移动本地传输网中引入多厂家传输设备进行探讨和分析,通过分析两种模式下引入不同厂家的设备对现网的影响,提出移动本地传输网中多厂家的引入策略和组网方式。 相似文献