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<正> 在电子产品设计过程中,有时要用到开关电容滤波器进行滤波。由于开关电容滤波器涉及到半导体集成电路的工艺水平,因此,人们希望有一种类似于运算放大器的电路模块,外加几个电阻和电容,再加上时钟,就可以构成开关电容滤波器。本文所介绍的开关电容滤波器设计软件——FilterCAD,就可 相似文献
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本文简单分析了2.2KW电力系统用直流操作电源移相全桥软开关拓扑结构,设计和选择了主电路的滤波电容和电感等元件,制作了软开关主电路的主要部件,包括高频变压器和谐振电感;根据设计的开关电源实际特点,选择了主功率管和次级整流二极管。 相似文献
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基于3V、0.34μm CMOS工艺技术,设计了一种提高信号幅度的自举模拟开关,其线性区的导通电阻约为0.5Ω;输入信号通过该开关后,动态范围达到满幅度,并能将O~3V的时钟电压提升到0~6V。该开关适用于A/D转换器中的采样/保持电路和开关电容的滤波电路。 相似文献
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一个完整的DTMF接收器电路集成了陷波(bandsplit)滤波器和数字编码功能。在滤波部分,高组滤波和拔号音频滤波等使用了开关电容技术。本文阐述了DTMF接收器电路在数模混合系统A540和数字系统T3313上的不同测试技术的实现. 相似文献
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Ren-Hung Hwang Ben-Jye Chang Min-Xiou Chen Kun-Chan Tsai 《Wireless Personal Communications》2006,39(1):41-61
For achieving high utilization and efficient code management of the OVSF code tree in 3G WCDMA networks, several researches have extensively studied. Based on combining both the code assignment and the reassignment mechanisms, it increases obviously high utilization and reduces completely the code blocking. Nevertheless, the required rate of traffic should be powers of two of the basic rate, i.e. 1R, 2R, 4R, …, etc., which is impractical and results in wasting the system bandwidth while the required rate is not powers of two of the basic rate. Several multi-code assignment mechanisms have proposed to reduce the waste rate. Nevertheless, these methods bring two inevitable drawbacks including, high complexity of handling multiple codes, and increasing the cost of using more rake combiners at both the base stations and mobile nodes. Therefore, we propose an adaptive grouping code assignment herein to provide a single channelization code for any possible rate of traffic, even though the required rate is not powers of two of the basic rate. Based on the dynamic programming algorithm, the adaptive grouping approach forms several calls into a group. Then it allocates a subtree to the group and adaptively shares the subtree codes for these calls in the concept of time-sharing of slots during a group cycle time. Therefore, the waste rate and code blocking are thus reduced obviously while using a single rake combiner. Since the delay problem may be occurred in such a time-sharing approach, we propose two schemes of cycle interleaving methods to reduce delay. Numerical results indicate that the proposed adaptive grouping approach reduces significantly the waste rate and thus increases the system utilization. Moreover, the proposed cycle interleaving scheme reduces data delay significantly.
Ren-Hung Hwang received his M.S. and Ph.D. degrees in computer science from University of Massachusetts, Amherst, Massachusetts, USA, in 1989 and 1993, respectively. He joined the Department of Computer Science and Information Engineering, National Chung Cheng University, Chia-Yi, Taiwan, in 1993, where he is now a full Professor and the Chair of the Department of Communication Engineering. His research interests include Internet QoS, peer-to-peer infrastructure design, and 3G QoS.
Ben-Jye Chang received his M.S. degree in computer engineering from University of Massachusetts, Lowell, in 1991 and the Ph.D. degree in computer science and information engineering from National Chung-Cheng University, Taiwan, in 2001. He joined the Department of Computer Science and Information Engineering faculty at Chaoyang University of Technology, Taiwan, in 2002, where he is currently an Associate Professor. His research interests include QoS-based networks, QoS wirless networking, resource management for wireless networks and mobile cellular networks, and performance evaluation of networks.
Min-Xiou Chen received the BS degree in computer science and information engineering from Tung Hai University, Tai-Chung, Taiwan, in 1996, and the MS and PhD degrees in computer science and information engineering from National Chung Cheng University, Chia-Yi, Taiwan, in 1998 and 2005, respectively. He is now an assistant professor at the Department of Computer Science and Information Engineering, Chung Hua University, Hsin-Chu, Taiwan. His research interests include wireless communication, SIP, sensor network and resource management in WCDMA systems. He is a member of the IEEE.
Kun-Chan Tsai received the BS degree in information engineering and computer science from Feng Chia University, Taichung, Taiwan, in 2001, and the MS degree in computer science and information engineering from National Chung Cheng University, Chia-Yi, Taiwan, in 2003. His research interests include wireless communications and resource management in WCDMA systems. 相似文献
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Supermedia-enhanced Internet-based telerobotics 总被引:4,自引:0,他引:4
Elhajj I. Ning Xi Wai Keung Fung Yun-Hui Liu Hasegawa Y. Fukuda T. 《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》2003,91(3):396-421
This paper introduces new planning and control methods for supermedia-enhanced real-time telerobotic operations via the Internet. Supermedia is the collection of video, audio, haptic information, temperature, and other sensory feedback. However, when the communication medium used, such as the Internet, introduces random communication time delay, several challenges and difficulties arise. Most importantly, random communication delay causes instability, loss of transparency, and desynchronization in real-time closed-loop telerobotic systems. Due to the complexity and diversity of such systems, the first challenge is to develop a general and efficient modeling and analysis tool. This paper proposes the use of Petri net modeling to capture the concurrency and complexity of Internet-based teleoperation. Combined with the event-based planning and control method, it also provides an efficient analysis and design tool to study the stability, transparency, and synchronization of such systems. In addition, the concepts of event transparency and event synchronization are introduced and analyzed. This modeling and control method has been applied to the design of several supermedia-enhanced Internet-based telerobotic systems, including the bilateral control of mobile robots and mobile manipulators. These systems have been experimentally implemented in three sites test bed consisting of robotic laboratories in the USA, Hong Kong, and Japan. The experimental results have verified the theoretical development and further demonstrated the stability, event transparency, and event synchronization of the systems. 相似文献
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随着业务类型的丰富和多样化,低时延、高带宽、数据私密性、高可靠性等成为业务普遍的要求。边缘计算、雾计算、分布式云、算力网络等方案相继被提出,并在产学研各界引发了深度的研究和探索。针对“多级的算力分布以及算力的协同将是未来算力结构的主流”这一观点,产业内外达成了共识,算力管理、分配、调度等与资源优化相关的问题也成为当下的研究热点和重点攻关方向。为此,面向未来的算力供给结构,首先描述了学术界、产业界资源调度优化问题的最新进展,总结了当前的主要方法论和工程实施架构;然后,针对两种典型的云边协同场景,从场景拆分、调度目标、求解方案依次进行分析,给出了适应场景特性的资源调度优化参考方案。 相似文献
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通过匹配星载CALIOP过境合肥时间,筛选Aerosol-lidar的观测数据,选取4个典型天气个例[沙尘天气、多云天气、中度污染(无云)、中度污染(有云)],对合肥地区的气溶胶进行联合观测,并对气溶胶的类型、气溶胶的变化、气溶胶污染的成因及来源进行分析。结果表明,多云天气下,星载激光雷达对底层气溶胶探测时会受到天气的影响,而地基激光雷达的探测效果较佳,可以通过定点连续观测距离的校正信号准确地反映气溶胶含量和变化特点。星-地激光雷达的联合观测可以更好地分析多种复杂天气的气溶胶变化。联合观测结果表明:轻度污染的沙尘型和受污染的浮尘型气溶胶主要集中在0.8~1.6 km高度范围内,退偏振比集中在0.18~0.20之间;多云天气的气溶胶主要为污染大陆型,集中在0.4~1.2 km高度范围内,其退偏振比在0.015~0.020之间,气溶胶含量很少且为具有球形粒子属性的细颗粒物;中度污染(无云)天气的气溶胶同时包含污染浮尘型和污染大陆型,主要集中在0.3~1.3 km高度范围内,退偏振比在0.08以下,具有明显的球形粒子属性;中度污染(有云)天气的气溶胶也同时包含污染浮尘型和污染大陆型,主要集中在0.8~1.4 km高度范围内,退偏振比在0.075~0.100范围内,为粒径较小的球形粒子。 相似文献
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Fernando J. Velez Orlando Cabral Francisco Merca Vasos Vassiliou 《Telecommunication Systems》2012,50(1):31-45
In this paper an all-IP Enhanced-Universal Mobile Telecommunications System (E-UMTS) is considered, where enhancements include
link level behavior, high-speed downlink packet access (HSDPA) channel, resource management, Diffserv architecture, and Radio
Resource Management schemes. An overview of E-UMTS deployment scenarios and service needs is presented based on the views
of relevant players. Deployment and mobility scenarios are considered, including expected population density and usage of
service mix for three environments, namely offices, urban/vehicular, and business city center. In addition, based on population
and service penetration values, E-UMTS traffic generation and activity models are described and characterized. Based on these
scenarios and characterizations, system level simulations are carried out and the enhanced service quality performance is
demonstrated, including blocking probability, handover failure probability and end-to-end delay in each deployment scenario.
By using system level simulations, services and environmental conditions can be mapped into deployment strategies (and supported
system capacity) whose evaluation is essential prior to field trials and real implementation. On the one hand, costs depend
on the prices of the spectrum, equipment, operation and maintenance, as well as on the number of cells which, in turn, depends
on the cell radius. On the other, revenues depend on the price per MB and on the supported throughput. As the goal of operators
and service providers is to maximize the profit, the profit in percentage was obtained for the three considered scenarios.
Its optimum values are found for cell radii around 31, 257, and 310 m for offices, vehicular and business city center scenarios,
respectively. 相似文献
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Camden C. Cutright Jacob L. Harris Srivatsan Ramesh Saad A. Khan Jan Genzer Stefano Menegatti 《Advanced functional materials》2021,31(47):2104164
This study presents a comprehensive survey of microgel-coated materials and their functional behavior, describing the complex interplay between the physicochemical and mechanical properties of the microgels and the chemical and morphological features of substrates. The cited literature is articulated in four main sections: i) properties of 2D and 3D substrates, ii) synthesis, modification, and characterization of the microgels, iii) deposition techniques and surface patterning, and iv) application of microgel-coated surfaces focusing on separations, sensing, and biomedical applications. Each section discusses – by way of principles and examples – how the various design parameters work in concert to deliver functionality to the composite systems. The case studies presented herein are viewed through a multi-scale lens. At the molecular level, the surface chemistry and the monomer make-up of the microgels endow responsiveness to environmental and artificial physical and chemical cues. At the micro-scale, the response effects shifts in size, mechanical, and optical properties, and affinity towards species in the surrounding liquid medium, ranging from small molecules to cells. These phenomena culminate at the macro-scale in measurable, reversible, and reproducible effects, aiming in a myriad of directions, from lab-scale to industrial applications. 相似文献
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针对勘探、油藏井位部署过程中涉及的地理位置、勘探开发历程、油藏地质特征、产能状况等重要环节,对油田各级地质构造、三级储量、沉积相、井位等勘探开发图形对象叠加地形地貌在平面上进行多尺度、多层系的图形展示,并结合地质信息服务和企业数据服务,实现了探区内地震资料处理、解释一体化查询展示、已探邻井相关资料一体化研究、正钻井生产状况实时查询、区块内岩性、物性统计分析、油气储量分布情况展示、井位的在线编辑及成果标注等功能,有效支撑井位部署过程中的各种数据查询、在线踏勘、井位编辑,统计分析以及成果展示,从而提高油田井位部署的效率及水平。 相似文献
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光刻与微纳制造技术的研究现状及展望 总被引:1,自引:0,他引:1
首先介绍了微纳制造的关键工艺技术——光刻技术。回顾了光刻技术的发展历程,介绍了各阶段主流光刻技术的基本原理和特点。阐述了国内外对光刻技术的研究现状,并讨论了光刻与微纳制造技术面临的挑战及其需要解决的关键性技术问题。然后重点介绍了浸没光刻、极紫外光刻、电子束光刻、离子束光刻、X射线光刻、纳米压印光刻等技术的概念、发展过程和特点,并对不同光刻技术的优缺点和生产适用条件进行了比较。最后结合国内外生产商、工程师和研究学者的研究成果,对光刻技术的未来发展做出展望。 相似文献
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This paper extends the timing test model in [5] to be more realistic by including the effects of the test fixtures between
a device under test and a tester. The paper enables analyzing the trade-offs that arise between the predicted yield and the
required overall test environment timing accuracy (OTETA) which involves the tester overall timing accuracy (OTA) and the
test fixtures' impacts. We specifically focus on the application of the extended model to predict the test yield of standard
high-speed interconnects, such as PCI Express, Parallel/Serial RapidIO, and HyperTransport. The extended model reveals that
achieving an actual yield of 80% with a test escape of 300 DPM (Defects Per Million) requires an equivalent OTETA that is
about half the acceptable absolute limit of the tested parameter.
Baosheng Wang received his B.S. degree from Beijing University of Aeronautics and Astronautics (BUAA), Beijing, P.R. China, in 1997 and
M.S. degree from Precision Instrument & Mechanical Engineering from the Tsinghua University, Beijing, P. R. China in 2000.
In 2005, he received his Ph.D. degree in Electrical Engineering from the University of British Columbia (UBC), Vancouver,
BC, Canada.
During his Master study, he was doing MEMS, Micro Sensors and Digital Signal processing. From 2000 to 2001, he worked in Beijing
Gaohong Telecommunications Company as a hardware engineer in ATM technology. Currently, he is a Design-for-Test (DFT) engineer
at ATI Technologies Inc., Markham, Ontario, Canada.
He publishes widely at international conferences and journals. His primary research interests are time-driven or timing-oriented
testing methodologies for System on-a-Chip (SoC). These fields include test time reduction for SRAMs, accelerated reliability
test for non-volatile memories, yield analysis for SoC timing tests, SoC path delay timing characterization and embedded timing
measurements.
Andy Kuo is currently a Ph.D student of System on a Chip (SoC) Research Lab at the Department of Electrical and Computer Engineering,
University of British Columbia. He received his M.A.Sc. and B.A.Sc in electrical and computer engineering from University
of British Columbia and University of Toronto in 2004 and 2002 respectively. His research interests include high-speed signal
integrity issues, jitter measurement, serial communications.
Touraj Farahmand received the B.Sc. degree in Electrical Engineering from Esfahan University of Technology, Esfahan, Iran in 1989 and the
M.Sc. in Control Engineering from Sharif university of Technology, Tehran, Iran in 1992. After graduation, he joined the Electrical
and Computer Research center of Esfahan University of Technology where he was involved in the DSP algorithm development and
design and implementation of the control and automation systems. Since October 2001, he has been working in the area of high-speed
signal timing measurement at SoC (System-on-a-Chip) lab of UBC (University of British Columbia) as a research engineer. His
research interests are signal processing, jitter measurement, serial communication and control.
André Ivanov is Professor in the Department of Electrical and Computer Engineering, at the University of British Columbia. Prior to joining
UBC in 1989, he received his B.Eng. (Hon.), M. Eng., and Ph.D. degrees in Electrical Engineering from McGill University. In
1995–96, he spent a sabbatical leave at PMC-Sierra, Vancouver, BC. He has held invited Professor positions at the University
of Montpellier II, the University of Bordeaux I, and Edith Cowan University, in Perth, Australia.
His primary research interests lie in the area of integrated circuit testing, design for testability and built-in self-test,
for digital, analog and mixed-signal circuits, and systems on a chip (SoCs). He has published widely in these areas and holds
several patents in IC design and test. Besides testing, Ivanov has interests in the design and design methodologies of large
and complex integrated circuits and SoCs.
Dr. Ivanov has served and continues to serve on numerous national and international steering, program, and/or organization
committees in various capacities. Recently, he was the Program Chair of the 2002 VLSI Test Symposium (VTS'02) and the General
Chair for VTS'03 and VTS'04. In 2001, Ivanov co-founded Vector 12, a semiconductor IP company. He has published over 100 papers
in conference and journals and holds 4 US patents. Ivanov serves on the Editorial Board of the IEEE Design and Test Magazine,
and Kluwer's Journal of Electronic Testing: Theory and Applications. Ivanov is currently the Chair of the IEEE Computer Society's
Test Technology Technical Council (TTTC). He is a Golden Core Member of the IEEE Computer Society, a Senior Member of the
IEEE, a Fellow of the British Columbia Advanced Systems Institute and a Professional Engineer of British Columbia.
Yong Cho received the B.S. degree from Kyung Pook National Unviersity, Korea, in 1981 and the M.S. degree from in electrical and computer
engineering from the University of South Carolina, Columbia, S.C., in 1988 and the Ph.D. degree in electrical engineering
and applied physics from Case Western Reserve University, Cleveland, OH, in 1992.
He is currently a Professor with the Department of Electronics Engineering, Konkuk University, Seoul, Korea. His recent research
interests include SoC Design and Verification, H/W and S/W co-design, and embedded programming on SoC.
Sassan Tabatabaei received his PHD in Electrical Engineering from the University of British Columbia, Vancouver, Canada in 2000. Since then,
he has held several senior technical positions at Vector12 Corp, Guide Technology, and Virage Logic.
His professional and research interests include mixed-signal design and test, and signal integrity and jitter test methodologies
for high-speed circuits and multi-Gbps serial interfaces. He has published several papers and holds a US patent in the area
of timing and jitter measurement. Currently, he holds the position of the director for embedded test at Virage Logic Corporation. 相似文献