检索结果-内蒙古大学图书馆

IEEE PhotonicsGlobal@Singapore, IPGC

作者： Qian Wang Seng-Tiong Ho Yingyan Huang Data Storage Institute Agency for Science Agency for Science Technology and Research Singapore Department Electrical Engineering and Computer Science Northwestern University Evanston IL USA

Modal characterization of silicon nanophotonic waveguide and its coupling to an optical fiber are investigated, which include: 1) a full-vectorial modal analysis of silicon nanophotonic waveguide and a TM-pass nanophotonic polarizer based on a simple taper structure; 2) a superlens based coupling structure between nanophotonic waveguide and singlemode fiber with a designed coupling loss ~0.64 dB and 3) a brief introduction on our cluster computing simulation platform and computational intelligence based optimizations for nanophotonic circuits.

关键词： Silicon Optical waveguides Optical coupling Optical fiber polarization Coupling circuits Optical fibers Modal analysis Nanostructures Optical design Optical fiber losses

来源：评论

学校读者我要写书评

暂无评论

Training overhead for decoding random linear network codes

Training overhead for decoding random linear network codes

引用

MILCOM, Military Communications Conference

作者： Maximilian Riemensberger Yalin Evren Sagduyu Michael L. Honig Wolfgang Utschick Associate Institute for Signal Processing Munich University of Technology Munich Germany Department of Electrical Engineering and Computer Science Northwestern University Evanston USA

We consider multicast communications from a single source to multiple destinations over a network of erasure channels. Linear network coding maximizes the achievable (min-cut) rate, and a distributed code assignment can be realized by choosing codes randomly at the intermediate nodes. It is typically assumed that the coding information (combining coefficients) at each node is included in the packet overhead, and forwarded to the destination. Instead, we assume that the network coding matrix is communicated to the destinations by appending training bits to the data bits at the source. End-to-end channel coding can then be applied to the training and data either separately, or jointly, by coding across both training and information bits. Ideally, the training overhead should balance the reliability of communicating the network matrix with the reliability of data detection. We maximize data throughput as a function of the training overhead, and show how it depends on the network size, erasure probability, number of independent messages, and field size. The combination network is used to illustrate our results, and shows under what conditions throughput is limited by training overhead.

关键词： Decoding Network coding Telecommunication network reliability Routing Network topology Wireless networks Channel coding Multicast communication Throughput Signal processing

来源：评论

学校读者我要写书评

暂无评论

An investigation on evolutionary gradient search for multi-objective optimization

An investigation on evolutionary gradient search for multi-o...

引用

Congress on Evolutionary Computation

作者： C. K. Goh Y. S. Ong K. C. Tan E. J. Teoh Agency for Science Technology and Research Data Storage Institute Singapore School of Computer Engineering Nanyang Technological University Singapore Department of Electrical and Computer Engineering National University of Singapore Singapore

Evolutionary gradient search is a hybrid algorithm that exploits the complementary features of gradient search and evolutionary algorithm to achieve a level of efficiency and robustness that cannot be attained by either techniques alone. Unlike the conventional coupling of local search operators and evolutionary algorithm, this algorithm follows a trajectory based on the gradient information that is obtain via the evolutionary process. In this paper, we consider how gradient information can be obtained and used in the context of multi-objective optimization problems. The different types of gradient information are used to guide the evolutionary gradient search to solve multi-objective problems. Experimental studies are conducted to analyze and compare the effectiveness of various implementations.

关键词： Optimization Evolutionary computation Programming Algorithm design and analysis Trajectory Measurement Electronic mail

来源：评论

学校读者我要写书评

暂无评论

Exchange bias and magnetotransport properties in IrMn/NiFe/FeMn structures

引用

Physical Review B 2008年第18期78卷 184413-184413页

作者： Z. B. Guo Y. H. Wu J. J. Qiu B. Y. Zong G. C. Han Data Storage Institute Agency for Science Technology and Research (A*STAR) DSI Building 5 Engineering Drive 1 Singapore 117608 Department of Electrical and Computer Engineering National University of Singapore Singapore 119260

For the double exchange-biased IrMn/NiFe/FeMn structures, the pinning directions at IrMn/NiFe and NiFe/FeMn interfaces were set either parallel or antiparallel to each other by field annealing. Exchange bias and magnetotransport properties in IrMn/NiFe/FeMn trilayers were studied and compared with those of IrMn/NiFe and NiFe/FeMn bilayers. The dependence of exchange bias on the thickness of NiFe layer was different for parallel and antiparallel pinnings. A remarkable increase in resistance was observed which should be attributed to domain-wall resistance induced by the twisted spin structure. The spin configuration of twisted spin structure was simulated by one-dimensional atomic model.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Distributed precoder optimization for interfering MISO channels

Distributed precoder optimization for interfering MISO chann...

引用

ITG Workshop on Smart Antennas

作者： David A. Schmidt Andreas Grundinger Wolfgang Utschick Michael L. Honig Institute for Signal Processing Technische Universität München Munich Germany Department of Electrical Engineering and Computer Science Northwestern University Evanston IL USA

In this paper, we examine the problem of two multiple-input-single-output (MISO) links that interfere with each other. We discuss some straightforward strategies for the users to optimize their rates and show how a certain degree of cooperation between the users can lead to an improvement of both individual links. We propose an algorithm that is based on the users exchanging 'interference prices' and is realizable in a distributed manner. The algorithm converges towards a locally sum-rate optimal solution and exhibits nearly identical performance as a non-distributed gradient ascent algorithm, outperforming the straightforward strategies over the complete range of noise powers.

关键词： Interference Transmitters Receiving antennas Transmitting antennas Time sharing computer systems Additive noise Array signal processing Signal processing computer science Throughput

来源：评论

学校读者我要写书评

暂无评论

Multiple Heterogeneous Ant Colonies with Information Exchange

Multiple Heterogeneous Ant Colonies with Information Exchang...

引用

Congress on Evolutionary Computation

作者： Arash Arami Bijan Rahmizadeh Rofoee Caro Lucas Control and Intelligent Processing Center of Excellence (CIPCE) school of Electrical and Computer Engineering University of Tehran Tehran Iran Electrical and Computer Engineering Department Tabriz University Tabriz Iran School of Cognitive Science Institute of Studies in Theoretical Physics and Mathematics Tehran Iran CIPCE school of Electrical and Computer Engineering University of Tehran Tehran Iran

The method of multiple heterogeneous ant colonies with information exchange (MHACIE) is presented in this paper with emphasis on the speed of finding the optimal solution and the corresponding computational complexity. The proposed method which is inspired by biology and psychology has a structure composed of several ant colonies. These colonies participate in solving problems in a concurrently manner and also exchange information with each other in communicational steps. Each ant colony is considered as an intelligent agent with behavioral traits. These behavioral traits play a key role in the solving procedure, in interrelation circumstances and in installation of relations. Faster solutions have been achieved using different employments of agents in the algorithm structure. Experimental results show the superiority of Multiple heterogeneous ant colonies algorithm in comparison to the standard ant colony system (ACS) and particle swarm optimization (PSO) algorithms on different benchmarks. A dynamic, control engineering benchmark is also provided in order to gain a more complete evaluation of the proposed algorithm.

关键词： Benchmark testing Evolution (biology) Optimization Heuristic algorithms Evolutionary computation Electronic mail Educational institutions

来源：评论

学校读者我要写书评

暂无评论

Crystalline Amorphous Semiconductor Superlattice

引用

Physical Review Letters 2008年第13期100卷 136101-136101页

作者： T. C. Chong L. P. Shi X. Q. Wei R. Zhao H. K. Lee P. Yang A. Y. Du Data Storage Institute A⋆STAR (Agency for Science Technology and Research) Singapore 117608 Electrical Computer Engineering Department National University of Singapore Singapore 117576 Singapore Synchrotron Light Source (SSLS) National University of Singapore Singapore 117603 Institute of Microelectronics A⋆STAR (Agency for Science Technology and Research) Singapore 117685

A new class of superlattice, crystalline amorphous superlattice (CASL), by alternatively depositing two semiconductor materials, is proposed. CASL displays three states depending on the component materials’ phase: both polycrystalline phases, both amorphous phases, and one polycrystalline phase while another amorphous phase. Using materials capable of reversible phase transition, CASL can demonstrate reversibility among three states. GeTe/Sb2Te3 CASL has been synthesized and proved by x-ray reflectometry and TEM results. The reversible transition among three states induced by electrical and laser pulse was observed. The changes in the optical absorption edge, electrical resistivity, thermal conductivity, and crystallization temperature as a function of layer thickness are interpreted as quantum or nanoeffects. The unique properties of CASL enable the design of materials with specific properties.

关键词： Crystalline materials

来源：评论

学校读者我要写书评

暂无评论

An Energy Efficient, Low Cost, Hybrid Storage System Based on Utility

An Energy Efficient, Low Cost, Hybrid Storage System Based o...

引用

Japan-China Joint Workshop on Frontier of computer science and Technology (FCST)

作者： Lingfang Zeng Dan Feng Bharadwaj Veeravalli Qingsong Wei Key Laboratory of Information Storage Ministry of Education Huazhong University of Science and Technology China Department of Electrical and Computer Engineering National University of Singapore Singapore Data Storage Institute Singapore

To get large disk-like characteristics and offset the significant power demands of hard disk drives, we propose a fully functional hybrid archive system (called Pseudodisk) composed of an array of disks and a tape library. To get an energy conservation, low cost archive system, Pseudodisk uses data value model and utility function to guild data management. Two novel algorithms are proposed for data placement and data migration, which are referred to as utility-based data placement (UDP) and and system utility percentage (SUP) algorithms respectively. To validate the efficiency of the proposed archive system, we conduct the performance evaluation and the power-saving simulation.

关键词： Energy efficiency Energy storage Power demand Hard disks Libraries Energy conservation Cost function Power system modeling Energy management Power system management

来源：评论

学校读者我要写书评

暂无评论

A shared-relay cooperative diversity scheme based on joint channel and network coding

A shared-relay cooperative diversity scheme based on joint c...

引用

International Symposium on Information Theory and Its Applications, ISITA

作者： Xiaoyan Xu Mark F. Flanagan Christian Koller Norbert Goertz Institute for Digital Communications Joint Research Institute for Signal & Image Processing University of Edinburgh UK Department of Electronics Computer Science and Systems (DEIS) University of Bologna Italy Department of Electrical Engineering University of Notre Dame Notre Dame IN USA

ISBN: (纸本)9781424420681

In cooperative communications, the technique of algebraic code superposition (or network coding) may efficiently utilize limited communications resources to produce spatial diversity. In this paper, we propose a simple cooperative diversity scheme for the scenario of two sources sharing a single relay. No cooperative coding is required at the sources, and only very simple interleave-and-superpose operations are performed at the relay. We propose a novel computationally efficient message passing algorithm at the destination's decoder which utilizes spatial diversity gathered over multiple transmission frames. We show that despite the simplicity of the proposed scheme, diversity gains are efficiently leveraged by the simple combination of channel coding at the sources and network coding at the relay.

关键词： Network coding Decoding Relays Parity check codes Electronic mail Fading Message passing Diversity methods Information theory Digital communication

来源：评论

学校读者我要写书评

暂无评论

The extended invariance principle applied to joint time-delay, frequency, and DOA estimation

The extended invariance principle applied to joint time-dela...

引用

International Conference on Acoustics, Speech, and Signal processing (ICASSP)

作者： Felix Antreich Josef A. Nossek Gonzalo Seco A. Lee Swindlehurst Institute for Communications and Navigation German Aerospace Center Wessling Germany Institute for Circuit Theory & Signal Processing Munich University of Technology Germany Department of Telecommunications & Systems Engineering Universitat Autonoma de Barcelona Spain Department of Electrical Engineering & Computer Science University of California Irvine CA USA

This paper deals with the joint estimation of temporal (time- delay, Doppler frequency) and spatial (direction-of-arrival, DOA) parameters of several replicas of a known signal in an unknown spatially correlated field. Unstructured and structured models have been proposed in the literature. The former suffers from a severe performance degradation in some scenarios, whereas the latter involves huge complexity. It is shown how the extended invariance principle (EXIP) can be applied to obtain estimates with the quality of those of the structured model, but with the complexity of the unstructured one. We present a method to improve the quality of the time- delay and Doppler estimates obtained with an unstructured spatial model when an estimate of the DOAs is available. Exemplarily, simulation results for time-delay estimation for GPS (global positioning system) are included and confirm that our proposal approaches the Cramer-Rao lower bound (CRLB) of the structured model even when suboptimal DOA estimates obtained by ESPRIT are introduced.

关键词： Frequency estimation Direction of arrival estimation Global Positioning System Delay estimation data models Sensor arrays Signal processing Gaussian noise Aerospace engineering Navigation

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：