检索结果-内蒙古大学图书馆

International Symposium on parallel Architectures, Algorithms, and Programming

作者： Yi, Wei Tang, Yuhua Wang, Guibin Fang, Xudong National Laboratory for Parallel and Distributed Processing School of Computer National University of Defense Technology Changsha China

ISBN: (纸本)9780769543123

Recently, GPGPU has been adopted well in the High Performance Computing (HPC) field. The limited global memory bandwidth poses a great challenge to many GPGPU programmers trying to exploit parallelism within the CPUGPU heterogeneous platform. In this paper, we choose SWIM, a typical memory intensive application from the SPEC OMP 2001 benchmark suite, for case study. We attempt to optimize the performance and energy consumption of the application utilizing different memory access mechanisms and present optimization methods including matrix transposition and kernel fusion. The experimental results on the Intel CoreTM i920 CPU plus GeForce GTX 295 platform shows that, the proposed optimizing methods achieve a speedup of 8.7X over the original OpenMP program and reduce the energy consumption by 83% for the problem size of 2048*2048. © 2010 IEEE.

关键词： Energy utilization

来源：评论

学校读者我要写书评

暂无评论

Impact of imprecise programming of memristor on building hardware neural network

Impact of imprecise programming of memristor on building har...

引用

2nd Annual Conference on Electrical and Control Engineering, ICECE 2011

作者： Zhu, Xuan National Laboratory for Parallel and Distributed Processing School of Computer National University of Defense Technology ChangSha China

ISBN: (纸本)9781424481637

The application of memristor in building hardware neural network has accepted widespread interests, and may bring novel opportunities to neural computing. However, due to the limitation of programming precision, the conductance of memristor which represents stored information may deviate from theoretical value, and thus bring error to the neural computing results. In this paper, we analyze the impact of imprecise programming on building hardeware neural network through Monte Carlo simulation on feedback layer model. The results show that the fault-tolerance ability of neural network could well adapt to these errors, which further proves the potential of building neural networks using memristors. © 2011 IEEE.

关键词： Errors

来源：评论

学校读者我要写书评

暂无评论

iRank: Supporting proximity ranking for peer-to-peer applications

iRank: Supporting proximity ranking for peer-to-peer applica...

引用

15th International Conference on parallel and distributed Systems, ICPADS '09

作者： Fu, Yongquan Wang, Yijie National Key Laboratory for Parallel and Distributed Processing School of Computer National University of Defense Technology China

ISBN: (纸本)9780769539003

Proximity ranking according to end-to-end network distances (e.g., Round-Trip Time, RTT) can reveal detailed proximity information, which is important in network management and performance diagnosis in distributed systems. However, to the best of our knowledge, there has been no similar work on this subject in the P2P computing field. We present a distributed rating method iRank, that enables proximity rankings by providing discrete ratings in a distributed manner. It formulates the proximity ranking as a rating problem that faithfully captures the proximity based on noisy distance measurements scalably and practically. The primary challenge in inferring proximity rankings is enforcing distributed ratings with complex rating policies. Our solution is based on reconstructing ratings by decomposing a centralized rating method Maximum Margin Matrix Factorization (MMMF) into independent sub-problems, that can be efficiently solved in a decentralized manner. By relaxing the dependence on infrastructure nodes that are a single point of failure and limit scalability, iRank can gracefully handle network churns. Through real network latency data sets, we demonstrate that iRank can predict ratings with low distortion, which are smaller than 20 percentage worse than the centralized method, in the context of synthetic complex rating policies. © 2009 IEEE.

关键词： Complex networks

来源：评论

学校读者我要写书评

暂无评论

Improving performance portability for GPU-specific Open CL kernels on multi-core/many-core CPUs by analysis-based transformations

引用

Frontiers of Information technology & Electronic Engineering 2015年第11期16卷 899-916页

作者： Mei WEN Da-fei HUANG Chang-qing XUN Dong CHEN School of Computer National University of Defense Technology National Key Laboratory of Parallel and Distributed Processing

OpenCL is an open heterogeneous programming framework. Although OpenCL programs are func- tionally portable, they do not provide performance portability, so code transformation often plays an irreplaceable role. When adapting GPU-specific OpenCL kernels to run on multi-core/many-core CPUs, coarsening the thread granularity is necessary and thus has been extensively used. However, locality concerns exposed in GPU-specific OpenCL code are usually inherited without analysis, which may give side-effects on the CPU performance. Typi- cally, the use of OpenCL＇s local memory on multi-core/many-core CPUs may lead to an opposite performance effect, because local-memory arrays no longer match well with the hardware and the associated synchronizations are costly. To solve this dilemma, we actively analyze the memory access patterns using array-access descriptors derived from GPU-specific kernels, which can thus be adapted for CPUs by （1） removing all the unwanted local-memory arrays together with the obsolete barrier statements and （2） optimizing the coalesced kernel code with vectorization and locality re-exploitation. Moreover, we have developed an automated tool chain that makes this transformation of GPU-specific OpenCL kernels into a CPU-friendly form, which is accompanied with a scheduler that forms a new OpenCL runtime. Experiments show that the automated transformation can improve OpenCL kernel performance on a multi-core CPU by an average factor of 3.24. Satisfactory performance improvements axe also achieved on Intel＇s many-integrated-core coprocessor. The resultant performance on both architectures is better than or comparable with the corresponding OpenMP performance.

关键词： OpenCL Performance portability Multi-core/many-core CPU Analysis-based transformation

来源：评论

学校读者我要写书评

暂无评论

Optimizing adaptive synchronization in parallel simulators for large-scale parallel systems and applications

Optimizing adaptive synchronization in parallel simulators f...

引用

10th IEEE International Conference on Computer and Information technology, CIT-2010, 7th IEEE International Conference on Embedded Software and Systems, ICESS-2010, 10th IEEE Int. Conf. Scalable Computing and Communications, ScalCom-2010

作者： Xu, Chuanfu Che, Yonggang Fang, Jianbin Wang, Zhenghua National Laboratory for Parallel and Distributed Processing School of Computer National University of Defense Technology Changsha China

ISBN: (纸本)9780769541082

This paper addresses the optimization of parallel simulators for large-scale parallel systems and applications. Such simulators are often based on parallel discrete event simulation with conservative or optimistic protocols to synchronize the simulating processes. The paper considers how available future information about events and application behaviors can be efficiently extracted and further exploited to improve the performance of adaptive optimistic protocols. First, we extract information about future events and their dependencies in application traces to guide adaptive adjustments of time window in trace-driven parallel simulation. Second, we use information about application behaviors, specifically the iterative behavior found in many applications, to avoid the unnecessary adjustments of time window. These techniques are implemented in the BigSim simulator and tested by real-world and standard benchmark applications including Jacobi3D and HPL. The results show that our optimization approaches can reduce the execution times of simulation ranging from 11% up to 32%. Moreover, our methods are easy to implement and don't need to augment compilers or even modify the core codes of parallel simulators. © 2010 IEEE.

关键词： Simulators

来源：评论

学校读者我要写书评

暂无评论

Survey of DHT topology construction techniques in virtual computing environments

引用

science China(Information sciences) 2011年第11期54卷 2221-2235页

作者： ZHANG YiMing 1,2,LU XiCheng 1,2 & LI DongSheng 1,21 National laboratory for parallel and distributed processing (PDL),Changsha 410073,China 2 School of Computer,National University of Defense technology,Changsha 410073,China 1. National Laboratory for Parallel and Distributed Processing (PDL) Changsha 410073 China2. School of Computer National University of Defense Technology Changsha 410073 China

The Internet-based virtual computing environment (iVCE) is a novel network computing *** characteristics of growth,autonomy,and diversity of Internet resources present great challenges to resource sharing in *** DHT overlay (DHT for short) technique has various advantages such as high scalability,low latency,and desirable availability,and is thus an important approach to realizing efficient resource *** construction is a key technique for structured overlays that realizes basic overlay functions including dynamic maintenance and message *** this paper,we first introduce the traditional techniques of DHT topology construction,focusing mainly on dynamic maintenance and message routing of typical DHTs,DHT indexing techniques for complex queries,and DHT grouping techniques for matching domain *** then present recent advances in DHT topology construction techniques in iVCE taking advantage of the characteristics of Internet ***,we discuss the future of DHT topology construction techniques.

关键词： virtual computing environments DHT overlays topology construction distributed indexing flexible routing

来源：评论

学校读者我要写书评

暂无评论

On the feasibility of common-friend measurements for the distributed online social networks

On the feasibility of common-friend measurements for the dis...

引用

2012 7th International ICST Conference on Communications and Networking in China, CHINACOM 2012

作者： Fu, Yongquan Wang, Yijie National Key Laboratory for Parallel and Distributed Processing College of Computer Science National University of Defense Technology Hunan province 410073 China

ISBN: (纸本)9781467326995

distributed social networks have emerged recently. Nevertheless, recommending friends in the distributed social networks has not been exploited fully. We propose FDist, a distributed common-friend estimation scheme that estimates the number of common-friends between any pair of users without disclosing the friends' information. FDist uses privacy-preserving common-friend measurements to collect a small number of common-friend samples, and uses low-dimensional coordinates to estimate the number of common friends to other users. Simulation results on real-world social networks confirm that FDist is both scalable and accurate. © 2012 IEEE.

关键词： Social networking (online)

来源：评论

学校读者我要写书评

暂无评论

BCE: A privacy-preserving common-friend estimation method for distributed online social networks without cryptography

BCE: A privacy-preserving common-friend estimation method fo...

引用

2012 7th International ICST Conference on Communications and Networking in China, CHINACOM 2012

作者： Fu, Yongquan Wang, Yijie National Key Laboratory for Parallel and Distributed Processing College of Computer Science National University of Defense Technology Hunan province 410073 China

ISBN: (纸本)9781467326995

distributed online social networks (DOSN) have emerged recently. Nevertheless, recommending friends in the distributed social networks has not been exploited fully. We propose BCE (Bloom Filter based Common-Friend Estimation), a scalable and privacy-preserving common-friend estimation scheme that estimates the set of common friends without the need of cryptography techniques. First, BCE denotes each user using the identifiers created by the Peer-to-Peer underlay that are robust against the dictionary attacks. Second, BCE uses a Bloom filter to represent a friend list for scalability. Third, BCE estimates common friends of two users using the intersection of Bloom filters computed by one of their common friends, which ensures the privacy of friend lists against unknown users. Our privacy analysis shows that BCE hides the privacy of each user with a high probability. Simulations over real-world social-network data sets confirms that BCE is both accurate and scalable. © 2012 IEEE.

关键词： Social networking (online)

来源：评论

学校读者我要写书评

暂无评论

Effective top-down active learning for hierarchical text classification

引用

17th Pacific-Asia Conference on Knowledge Discovery and Data Mining, PAKDD 2013

作者： Li, Xiao Ling, Charles X. Wang, Huaimin Department of Computer Science University of Western Ontario Canada National Laboratory for Parallel and Distributed Processing National University of Defense Technology China

ISBN: (纸本)9783642374555

Hierarchical text classification is an important task in many real-world applications. To build an accurate hierarchical classification system with many categories, usually a very large number of documents must be labeled and provided. This can be very costly. Active learning has been shown to effectively reduce the labeling effort in traditional (flat) text classification, but few works have been done in hierarchical text classification due to several challenges. A major challenge is to reduce the so-called out-of-domain queries. Previous state-of-the-art approaches tackle this challenge by simultaneously forming the unlabeled pools on all the categories regardless of the inherited hierarchical dependence of classifiers. In this paper, we propose a novel top-down hierarchical active learning framework, and effective strategies to tackle this and other challenges. With extensive experiments on eight real-world hierarchical text datasets, we demonstrate that our strategies are highly effective, and they outperform the state-of-the-art hierarchical active learning methods by reducing 20% to 40% queries. © Springer-Verlag 2013.

关键词： Text processing

来源：评论

学校读者我要写书评

暂无评论

A prediction-based parallel replication algorithm in distributed storage system

引用

4th International Conference on Grid and Cooperative Computing - GCC 2005

作者： Wang, Yijie Zhang, Xiaoming National Laboratory for Parallel and Distributed Processing Institute of Computer National University of Defense Technology Changsha 410073 China

ISBN: (纸本)3540305106

Data replication can be used to reduce bandwidth consumption and access latency in the distributed system where users require remote access to large data objects. In this paper, according to the intrinsic characteristic of distributed storage system, the prediction-based parallel replication algorithm PPR is proposed. In the PPR, according to the characteristic of spatial data, the data that will be accessed is predicted, then the data is prefetched;during replication, according to the network state, several replicas of a data object are selected, which are of the least access cost;the different parts of the data object are transferred from these replicas, and they are used to make a new replica. The results of performance evaluation show that the PPR can utilize the network bandwidth efficiently, provide high data replication efficiency and substantially better access efficiency, and can avoid the interference between different replications efficiently. © Springer-Verlag Berlin Heidelberg 2005.

关键词： distributed computer systems

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：