首页 | 本学科首页   官方微博 | 高级检索  
检索     
共有20条相似文献,以下是第1-20项 搜索用时 312 毫秒

1.  Interpolation oriented parallel communication to optimize coupling in earth system modeling  
   Yingsheng JI  ;Yingzhuo ZHANG  ;Guangwen YANG《Frontiers of Computer Science in China》,2014年第4期
   Complicated global climate problems trigger researchers from different scientific disciplines to link multiphysics simulations called models for integrated modeling of climate changes by using a software framework called earth system modeling (ESM). As its critical component, coupler is in charge of connections and interactions among models. With the advance of next-generation models, greater data transfer volume and higher coupling frequency are expected to put heavy performance burden on coupler. High efficient coupling techniques are required. In this paper, we propose the sub-domain mapping method to improve the parallel coupling consisted of data transfer and data transformation. By using one specific interpolation oriented communication routing, the communication operations that are originally decentralized in various steps can be combined together for execution. This can reduce the redundant communications and the entailed synchronization costs. The tests on the Tianhe-lA (TH-1A) supercomputer show that our method can achieve 1.1 to 4.9 fold performance improve- ments. We also present further optimization solution for the multi-interpolation cases. The test results show that our method can achieve up to 3.4 fold speedup over the original coupling execution of the current climate system.    

2.  Wireless Cooperative Mesh Network:A New Architecture for Network Convergence  
   Yang Wendong  Cao Yueming  Xu Youyun《中兴通讯技术(英文版)》,2008年第3期
   The convergence of heterogeneous wireless networks is a trend in the evolution of wireless networks.A new architecture for network convergence,named Wireless Cooperative Mesh Network,is proposed to solve such emerging problems in convergence as transmission mode selection,load balancing,routing and handover.The new architecture is based on the structure of Wireless Mesh Networks (WMNs),and cooperative communication is also employed to further optimize its structure and upgrade its performance.It can thus obtain advantages of both the Mesh technology (high spectrum efficiency and dynamic self-organization) and cooperative communication (high diversity gain and high energy efficiency).The new architecture serves as an efficient solution for wireless network convergence.    

3.  The Design of Management Software for Network Device Faults  
   KOU Ya-nan  LI Guo-li  LI Zeng-zi Institute of Computer Architecture & Network  Xi'an Jiaotong University  Xi'an 710038  P. R. China《国际设备工程与管理》,2001年第6卷第1期
   1 Introduction The management of a network device is more and more important with a wide range of network applications. Our development software is network management based on Pure Java. Its functions are network Topo discovery, network devices fault management, network security management, network performance management, and process management, etc. Network devices fault management is an important part of the system. Network devices fault management includes server functions and client func…    

4.  State Grid Corporation of China in Development  
   《中国标准化(英文版)》,2011年第4期
   State Grid Corporation of China (SGCC) was established on December 29,2002,with the construction and operation of power grids as its core business covering 26 provinces (including autonomous regions and municipalities),88% of the Chinese territory and a population of more than one billion.SGCC has a management of more than 1.5 million people,and is currently operating the Philippine national power transmission network and seven power transmission projects in Brazil.In 2010,SGCC as the largest utility in the world ranked the 8th on the Fortune Global 500.    

5.  Survivability Evaluation in Large-Scale Mobile Ad-Hoc Networks  被引次数:1
   San-Cheng Peng《计算机科学技术学报》,2009年第24卷第4期
   Survivability refers to the ability of a network system to fulfill critical services in a timely manner to end users in the presence of failures and/or attacks.In order to establish a highly survivable system,it is necessary to measure its survivability to evaluate the performance of the system's services under adverse conditions.According to survivability requirements of large-scale mobile ad-hoc networks(MANETs),we propose a novel model for quantitative evaluation on survivability.The proposed model co...    

6.  A novel mathematical model for coverage in wireless sensor network  
   YAN Zhen-ya  ZHENG Bao-yu Institute of Signal and Information Processing  Nanjing University of Posts and Telecommunications  Nanjing 210003  China《中国邮电高校学报(英文版)》,2006年第13卷第4期
   1 Introduction With the development of the sensor, wireless communication, and computer science, many researches have been focused on the development of a novel wireless network named wireless Ad-hoc sensor networks. This network can be defined as a network that can be self-organized in Ad-hoc fashion. This includes many sensor nodes and its objective is to sense, collect, and process the information collected by the individual sensor nodes via their cooperation [2]. Because of its high pract…    

7.  A novel mathematical model for coverage in wireless sensor network  
   YAN Zhen-ya  ZHENG Bao-yu Institute of Signal and Information Processing  Nanjing University of Posts and Telecommunications  Nanjing 210003  China《中国邮电高校学报(英文版)》,2006年第13卷第4期
   1 Introduction With the development of the sensor, wireless communication, and computer science, many researches have been focused on the development of a novel wireless network named wireless Ad-hoc sensor networks. This network can be defined as a network that can be self-organized in Ad-hoc fashion. This includes many sensor nodes and its objective is to sense, collect, and process the information collected by the individual sensor nodes via their cooperation [2]. Because of its high pract…    

8.  PREPARATION AND STRVCTURAL EVOLUTION OF TiO_2 THINFILMS BY LOW PRESSURE MOCVD  
   W.J. Li  Z.M. Wu  J.F. Zhao  Z.H. Wu  X.L.Zhao and B.C. Cai《金属学报(英文版)》,2000年第13卷第6期
   1. IntroductionTitanium dioxide (TiO2) films are widely used for electrical and optical applications because of its high dielectric constant, its chemical stability and its high refractive i.de.[1--2].Tioz thin films can be prepared by various thin film deposition techniquesl3--8]. Amongthese techniques, chemical vapor deposition (CVD) is considered as a useful method to deposit high quality thin films with large area uniformity and well--controlled stoichiometry.Crystalline TiOZ exists th…    

9.  Analysis models and methods on the network storage system I/O performance  
   刁莹  姚念民《哈尔滨工业大学学报(英文版)》,2012年第19卷第4期
   Network storage provides high scalability, availability and flexibility for storage systems, and is widely applied to many fields. Particularly, I/O performance is of great significance. Its application is wide and expanding rapidly. I/O performance has already become the bottleneck of the whole performance of computer systems for a long time, and under the condition of the present computer technology, I/O performance optimization method looks especially important. In the paper, I/O performance model was analyzed based on the combination of quasi birth, death process and queuing model, and then solved the model. A number of important related performance indicators and the relationship between them were given. By the way of example, this method can show the I/O performance more accurately. Finally, we got some useful conclusions, which may be used to evaluate network storage performance, and are the basis of confirming I/O scheduling strategy.    

10.  PartialRC: A Partial Recomputing Method for Efficient Fault Recovery on GPGPUs  
   徐新海  杨学军  薛京灵  林宇斐  林一松《计算机科学技术学报》,2012年第27卷第2期
   GPGPUs are increasingly being used to as performance accelerators for HPC (High Performance Computing) applications in CPU/GPU heterogeneous computing systems, including TianHe-1A, the world’s fastest supercomputer in the TOP500 list, built at NUDT (National University of Defense Technology) last year. However, despite their performance advantages, GPGPUs do not provide built-in fault-tolerant mechanisms to offer reliability guarantees required by many HPC applications. By analyzing the SIMT (single-instruction, multiple-thread) characteristics of programs running on GPGPUs, we have developed PartialRC, a new checkpoint-based compiler-directed partial recomputing method, for achieving efficient fault recovery by leveraging the phenomenal computing power of GPGPUs. In this paper, we introduce our PartialRC method that recovers from errors detected in a code region by partially re-computing the region, describe a checkpoint-based faulttolerance framework developed on PartialRC, and discuss an implementation on the CUDA platform. Validation using a range of representative CUDA programs on NVIDIA GPGPUs against FullRC (a traditional full-recomputing Checkpoint-Rollback-Restart fault recovery method for CPUs) shows that PartialRC reduces significantly the fault recovery overheads incurred by FullRC, by 73.5% when errors occur earlier during execution and 74.6% when errors occur later on average. In addition, PartialRC also reduces error detection overheads incurred by FullRC during fault recovery while incurring negligible performance overheads when no fault happens.    

11.  一种用于RFID读写器的高集成CMOS功率放大器的设计与分析  
   高同强  张春  池保勇  王志华《半导体学报》,2009年第30卷第6期
   To implement a fully-integrated on-chip CMOS power amplifier(PA) for RFID readers,the resonant frequency of each matching network is derived in detail.The highlight of the design is the adoption of a bonding wire as the output-stage inductor.Compared with the on-chip inductors in a CMOS process,the merit of the bondwire inductor is its high quality factor,leading to a higher output power and efficiency.The disadvantage of the bondwire inductor is that it is hard to control.A highly integrated class-E PA is implemented with 0.18-μm CMOS process.It can provide a maximum output power of 20 dBm and a 1 dB output power of 14.5 dBm.The maximum power-added efficiency(PAE) is 32.1%.Also,the spectral performance of the PA is analyzed for the specified RFID protocol.    

12.  Design and performance analysis of tracking controller for uncertain nonlinear composite system using neural networks  
   Endong LIU   Yuanwei JING   Siying ZHANG《控制理论与应用》,2005年第3卷第2期
   Based on high order dyna mi c neural network, paper presents the tracking problem for uncertain nonlinear composite system,which contain s external disturbance,whose nonlinear ities are assumed to be unknown.A smooth contr oller is designed to guarantee a uniform ultimate boundedness property for the tracking error and a ll other signals in the closed loop.Certain meas ures are utilized to test its performance.No a priori knowledge of an upper bound on the “ optimal" weight and modeling error is required;the weights of neural networks are updated on-line.N umerical simulations performed on a simple example i llustrate and clarify the approach.    

13.  对具有电子枪装置的试验方法和特殊要求  
   《中国标准化(英文版)》,2011年第3期
   BackgroundAs two tasks of project "Development of International Standards for Chinese advantage Technologies",a National Science and Technology Major Project during China's 11th Five-Year Plan Period,two international standards IEC 60703:2008 Test Methods of Electric Heating Devices with Electron Gun and IEC 60519-7:2008 Safety of Electric Heating Devices Part: 7 Special Requirements for Electric Heating Devices with Electron Gun are based on Chinese advantage technologies,highly recognized by IEC/TC27 for its technological and conceptual innovations in the high-quality,high-level and high-efficiency way.    

14.  Design and performance analysis of tracking controller for uncertain nonlinear composite system using neural networks  
   Endong LIU  Yuanwei JING  Siying ZHANG《控制理论与应用(英文版)》,2005年第3卷第2期
   Based on high order dynamic neural network, this paper presents the tracking problem for uncertain nonlinear composite system, which contains external disturbance, whose nonlinearities are assumed to be unknown. A smooth controller is designed to guarantee a uniform ultimate boundedness property for the tracking error and all other signals in the dosed loop. Certain measures are utilized to test its performance. No a priori knowledge of an upper bound on the “optimal” weight and modeling error is required; the weights of neural networks are updated on-line. Numerical simulations performed on a simple example illustrate and clarify the approach.    

15.  Carbon nanotube-polypyrrole core-shell sponge and its application as highly compressible supercapacitor electrode  
   Peixu Li  Enzheng Shi  Yanbing Yang  Yuanyuan Shang  Qingyu Peng  Shiting Wu  Jinquan Wei  Kunlin Wang  Hongwei Zhu  Quan Yuan  Anyuan Cao  Dehai Wu《Nano Research》,2014年第7卷第2期
   A carbon nanotube (CNT) sponge contains a three-dimensional conductive nano- tube network, and can be used as a porous electrode for various energy devices. We present here a rational strategy to fabricate a unique CNT@polypyrrole (PPy) core-shell sponge, and demonstrate its application as a highly compressible supercapacitor electrode with high performance. A PPy layer with optimal thickness was coated uniformly on individual CNTs and inter-CNT contact points by electrochemical deposition and crosslinking of pyrrole monomers, resulting in a core-shell configuration. The PPy coating significantly improves specific capacitance of the CNT sponge to above 300 F/g, and simultaneously reinforces the porous structure to achieve better strength and fully elastic structural recovery after compression. The CNT@PPy sponge can sustain 1,000 compression cycles at a strain of 50% while maintaining a stable capacitance (〉 90% of initial value). Our CNT@PPy core-shell sponges with a highly porous network structure may serve as compressible, robust electrodes for supercapacitors and many other energy devices.    

16.  Optimizing Linpack Benchmark on GPU-Accelerated Petascale Supercomputer  
   王锋  杨灿群  杜云飞  陈娟  易会战  徐炜遐《计算机科学技术学报》,2011年第26卷第5期
   In this paper we present the programming of the Linpack benchmark on TianHe-1 system,the first petascale supercomputer system of China,and the largest GPU-accelerated heterogeneous system ever attempted before.A hybrid programming model consisting of MPI,OpenMP and streaming computing is described to explore the task parallel,thread parallel and data parallel of the Linpack.We explain how we optimized the load distribution across the CPUs and GPUs using the two-level adaptive method and describe the implementation in details.To overcome the low-bandwidth between the CPU and GPU communication,we present a software pipelining technique to hide the communication overhead.Combined with other traditional optimizations,the Linpack we developed achieved 196.7 GFLOPS on a single compute element of TianHe-1.This result is 70.1% of the peak compute capability,3.3 times faster than the result by using the vendor’s library.On the full configuration of TianHe-1 our optimizations resulted in a Linpack performance of 0.563 PFLOPS,which made TianHe-1 the 5th fastest supercomputer on the Top500 list in November,2009.    

17.  基于确定与随机Petri网的IEEE 1394b总线性能评价(英文)  
   王明  张春熹  伊小素《中国通信》,2013年第10卷第2期
   IEEE 1394b is a high-speed data bus that is widely used in local area networks and consumer electronics. To best utilize this data bus, we need to fully understand its performance. To evaluate its performance for both isochronous and asynchronous data transfers, we model the IEEE 1394b bus using Deterministic and Stochastic Petri Nets (DSPNs), and conduct simulations using TimeNET 4.0. Using the DSPNs model, we simulate both the average waiting times of isochronous and asynchronous packets. From the simulation results, we determine the factors that influence performance, such as throughput, size of packets, arrival rate of packets, number of isochronous channels, and bus configuration.    

18.  USN安全研究与设计  
   韩德志 耿红琴 谢长生 胡玉平《计算机科学》,2003年第30卷第9期
   With the development of networked storage, the USN converging NAS and SAN appears, USN has many virtues: high performance, low lost and so on, but its security becomes more complex. Considering the situation,with making a deeply research on the performance, characteristic, and the architecture of the USN, the paper designs and implements a USN-based security algorithm, in which, the encryption and decryption are performed on the clien-t. and the USN server only provides identity authentication for user and the integrity verification for data. The test result indicates the algorithm can prevent many kinds invalid attacks, and make few influences on performance of the USN.    

19.  Preface  
   Min-Yi Guo  Zi-Li Shao  Edwin Hsing-Mean Sha《计算机科学技术学报》,2011年第26卷第3期
   A supercomputer has been competitively ranked by its computing speed,memory and storage capacity,andparallel processing scalability year by year.    

20.  一种基于能量感知的延迟容忍移动无线传感器网络多拷贝路由协议(英文)  
   张琳娟  郜帅《中国通信》,2011年第8卷第8期
   The two-phase replication-based routing has great prospects for Delay Tolerant Mobile Sensor Network (DTMSN) with its advantage of high message delivery ratio, but the blind spraying and the low efficiency forwarding algorithm directly influences the overall network performance. Considering the characteristic of the constrained energy and storage resources of sensors, we propose a novel two-phase multi-replica routing for DTMSN, called Energy-Aware Sociality-Based Spray and Search Routing (ESR), which imple...    

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号