检索结果-内蒙古大学图书馆

IEEE Conference on Wireless Communications and Networking

作者： Yu Gu Baohua Zhao Yusheng Ji Jie Li Information Systems Architecture Science Research Division National Institute of Information Tokyo Japan State Key Laboratory of Networking and Switching Technology Beijing China Department of Computer Science Tsukuba Science City University of Tsukuba Ibaraki Japan

We address the optimal sink scheduling problem in wireless sensor networks (WSNs). The problem is inherently difficult since sink scheduling and data routing are tightly coupled. Previous approaches either have questionable performance due to no joint considerations, or are based on relaxed constraints. Our aim is to fill in this blank in the research. First, by discretizing continuous time, we develop a novel bound technique to connect time-varying routes with the placement of sinks. This bounding technique transforms time-related constraints into pattern-based ones and allows us to mathematically formulate this optimization in a pattern-based way. The complexity of directly solving this optimization is intractable; therefore, on the basis of column generation (CG), a computationally efficient algorithm is developed to reduce the complexity by decomposing the problem into sub-problems and iteratively solving them to approach optimality. Simulations demonstrate the efficiency of the algorithm and substantiate the importance of sink mobility in energy-constrained sensor networks.

关键词： Wireless sensor networks Optimization Relays Routing Processor scheduling Complexity theory USA Councils

来源：评论

学校读者我要写书评

暂无评论

Study on blocked LU decomposition on many-core architecture

引用

Gaojishu Tongxin/Chinese High technology Letters 2011年第3期21卷 248-253页

作者： Yu, Lei Liu, Zhiyong Ma, Yike Song, Fenglong Xu, Weizhi Ye, Xiaochun Key Laboratory of Computer System and Architecture Institute of Computing Technology Chinese Academy of Sciences Beijing 100190 China Graduate University of Chinese Academy of Sciences Beijing 100039 China

The authors studied the scientific application LU decomposition deeply. A speedup model for LU decomposition was proposed, and an algorithm for LU decomposition based on bit reverse xor (BRX) was implemented. Then a dynamic absolute balance policy (DABP) algorithm was presented. In order to estimate the algorithms of 2 dimensional (2D) scatter, BRX and DABP, two different estimation functions were given and they were used to estimate the load balance problem of the algorithms. These two functions verify that the DABP algorithm has the best load balance. The simulations of the three algorithms were performed on the many-core architecture Godson-T. The experiments prove that the speedup of the DABP algorithm is 46 and it is the best performance of the three algorithms.

关键词： computer architecture

来源：评论

学校读者我要写书评

暂无评论

Context-specific miRNA regulation network predicts cancer prognosis

Context-specific miRNA regulation network predicts cancer pr...

引用

IEEE International Conference on Systems Biology

作者： Xionghui Zhou Juan Liu Changning Liu Simon Rayner Fengji Liang Jingfang Ju Yinghui Li Shanguang Chen Jianghui Xiong School of Computer Science Wuhan University Wuhan China Bioinformatics Research Group Key Laboratory of Intelligent Information Processing Advanced Computing Research Laboratory Institute of Computing Technology Chinese Academy of Sciences (CAS) Beijing China Bioinformatics Group State Key Laboratory of Virology Wuhan Institute of Virology Chinese Academy of Sciences (CAS) Wuhan China Bioinformatics Group and Data Coordination Center State Key Laboratory of Space Medicine Fundamentals and Application China Astronaut Research and Training Center Beijing China Department of Pathology Stony Brook University Medical Center New York USA

MicroRNAs can regulate hundreds of target genes and play a pivotal role in a broad range of biological process. However, relatively little is known about how these highly connected miRNAs-target networks are remodelled in the context of various diseases. Here we examine the dynamic alteration of context-specific miRNA regulation to determine whether modified microRNAs regulation on specific biological processes is a useful information source for predicting cancer prognosis. A new concept, Context-specific miRNA activity (CoMi activity) is introduced to describe the statistical difference between the expression level of a miRNA's target genes and non-targets genes within a given gene set (context).

关键词： Breast cancer Context Correlation Biological processes Metastasis Tumors

来源：评论

学校读者我要写书评

暂无评论

Theoretical Treatment of Sink Scheduling Problem in Wireless Sensor Networks

Theoretical Treatment of Sink Scheduling Problem in Wireless...

引用

IEEE Conference on computer Communications Workshops

作者： Yu Gu Yusheng Ji Jie Li Baohua Zhao Information Systems Architecture Science Research Division National Institute of Informatics Department of Computer Science University of Tsukuba State Key Laboratory of Networking and Switching Technology

ISBN: (纸本)9781457702495

Sink Scheduling, in the form of scheduling multiple sinks among sink sites to leverage traffic burden, is an effective mechanism for the energy-efficiency of wireless sensor networks (WSNs). Due to the inherent difficulty (NP-hard in general), existing works on this topic mainly focus on heuristic/greedy algorithms and theoretic results remain unknown. In this paper, we fill in the research blank with two algorithms. The first one is based on the Column Generation (CG). It decomposes the original problem into two sub problems and solve them iteratively to approach the optimal solution. However, due to its high computational complexity, this algorithm is only suitable for small scale networks. The other one is a polynomial-time algorithm based on relaxation techniques to obtain an upperbound, which can serve as a performance benchmark for other algorithms on this problem. Through comprehensive simulations, we evaluate the efficiency of proposed algorithms.

关键词： Wireless sensor networks Performance metrics Sinks Relaxation Techniques Energy efficiency original problem algorithms

来源：评论

学校读者我要写书评

暂无评论

Using index in the MapReduce framework

Using index in the MapReduce framework

引用

12th International Asia Pacific Web Conference, APWeb 2010

作者： An, Mingyuan Wang, Yang Wang, Weiping Key Laboratory of Computer System and Architecture Graduate University of Chinese Academy of Sciences Beijing China Key Laboratory of Computer System and Architecture Chinese Academy of Sciences Institute of Computing Technology Beijing China

ISBN: (纸本)9780769540122

MapReduce is a programming framework introduced by Google for large-scale data processing. It is usually used in a scan-centric fashion where all the data are split into blocks and Maps are generated for each block to scan and process the data in the block, then Reduces merge outputs from all the Maps. When a query intends to process only a subset of the data selected by a predicate, this brute-force method may cause extra I/O overhead spent on irrelevant data, and the overhead for initiating so many Maps may be nontrivial given that the actually interesting data for the query is comparatively small in volume. We propose an approach to integrate the index into the MapReduce execution in which only an appropriate number of Maps are generated, each of which accesses the data using an index. This approach incurs random I/O and remote access to data, so the overall performance depends on both system parameters and the query characteristics. We build a cost model for both this index access execution and the traditional full scan execution. This cost model can be used to choose between the two execution modes before executing a query. Experiments show that the index access execution can greatly outperform full scan execution when the selectivity of the predicate is low, and the cost model predicts the actual execution cost very well so can be used to determine the execution plan for a query. © 2010 IEEE.

关键词： MapReduce

来源：评论

学校读者我要写书评

暂无评论

Extended selective encoding of scan slices for reducing test data and test power

Extended selective encoding of scan slices for reducing test...

引用

作者： Liu, Jun Han, Yinhe Li, Xiaowei Key Laboratory of Computer System and Architecture Institute of Computing Technology Graduate University of Chinese Academy of Sciences China School of Computer and Information Hefei University of Technology China

Test data volume and test power are two major concerns when testing modern large circuits. Recently, selective encoding of scan slices is proposed to compress test data. This encoding technique, unlike many other compression techniques encoding all the bits, only encodes the target-symbol by specifying a single bit index and copying group data. In this paper, we propose an extended selective encoding which presents two new techniques to optimize this method: a flexible grouping strategy, X bits exploitation and filling strategy. Flexible grouping strategy can decrease the number of groups which need to be encoded and improve test data compression ratio. X bits exploitation and filling strategy can exploit a large number of don't care bits to reduce testing power with no compression ratio loss. Experimental results show that the proposed technique needs less test data storage volume and reduces average weighted switching activity by 25.6% and peak weighted switching activity by 9.68% during scan shift compared to selective encoding. Copyright © 2010 The institute of Electronics, Information and Communication Engineers.

关键词： Filling

来源：评论

学校读者我要写书评

暂无评论

Integrating DBMSs as a read-only execution layer into Hadoop

Integrating DBMSs as a read-only execution layer into Hadoop

引用

11th International Conference on Parallel and Distributed computing, Applications and Technologies, PDCAT 2010

作者： An, Mingyuan Wang, Yang Wang, Weiping Sun, Ninghui Key Laboratory of Computer System and Architecture Graduate University of Chinese Academy of Sciences Chinese Academy of Sciences Beijing China Key Laboratory of Computer System and Architecture Institute of Computing Technology Chinese Academy of Sciences Beijing China

ISBN: (纸本)9780769542874

To obtain the efficiency of DBMS, HadoopDB combines Hadoop and DBMS, and claims the superiority over Hadoop in terms of performance. However, the approach of HadoopDB is simply putting MapReduce onto unmodified single-machined DBMSs which has several obvious weaknesses. In essence, HadoopDB is a parallel DBMS with fault tolerance, which incurs unnecessary overhead due to the DBMS legacy. Instead of augmenting DBMS with Hadoop techniques, we propose a new system architecture integrating modified DBMS engines as a read-only execution layer into Hadoop, where DBMS plays a role of providing efficient readonly operators rather than managing the data. Besides the obtained efficiency from DBMS engine, there are other advantages. The modified DBMS engine is able to directly process data from the HDFS (Hadoop Distributed File System) files at the block level, which means that the data replication can be handled by HDFS naturally, and the blocklevel parallelism is easily achieved. The global index access mechanism is added according to the MapReduce paradigm. The data loading speed is also guaranteed by directly writing the data into HDFS with simplified logic. Experiments show that our system outperforms both original Hadoop and HadoopDB styled system. © 2010 IEEE.

关键词： Database systems

来源：评论

学校读者我要写书评

暂无评论

P-GAS: Parallelizing a cycle-accurate event-driven many-core processor simulator using parallel discrete event simulation 10

P-GAS: Parallelizing a cycle-accurate event-driven many-core...

引用

24th Annual Workshop on Principles of Advanced and Distributed Simulation, PADS 2010

作者： Lv, Huiwei Cheng, Yuan Bai, Lu Chen, Mingyu Fan, Dongrui Sun, Ninghui Key Laboratory of Computer System and Architecture Institute of Computing Technology Chinese Academy of Sciences China Graduate School Chinese Academy of Sciences China

ISBN: (纸本)9781424472918

Multi-core processors are commonly available now, but most traditional computer architectural simulators still use single-thread execution. In this paper we use parallel discrete event simulation (PDES) to speedup a cycle-accurate event-driven many-core processor simulator. Evaluation against the sequential version shows that the parallelized one achieves an average speedup of 10.9× (up to 13.6×) running SPLASH-2 kernel on a 16-core host machine, with cycle counter differences of less than 0.1%. Moreover, super-linear speedups are achieved between running 1 thread and 8 threads due to reduced overhead of insert-event-to-queue time and increased cache size in parallel processing. We conclude that PDES could be an attractive option for achieving fast cycle-accurate many-core processor simulations. © 2010 IEEE.

关键词： Simulators

来源：评论

学校读者我要写书评

暂无评论

A novel post-silicon debug mechanism based on Suspect Window

A novel post-silicon debug mechanism based on Suspect Window

引用

作者： Gao, Jianliang Han, Yinhe Li, Xiaowei Key Laboratory of Computer System and Architecture Institute of Computing Technology Chinese Academy of Sciences Graduate University of Chinese Academy of Sciences Beijing China

Bugs are becoming unavoidable in complex integrated circuit design. It is imperative to identify the bugs as soon as possible through post-silicon debug. For post-silicon debug, observability is one of the biggest challenges. Scan-based debug mechanism provides high observability by reusing scan chains. However, it is not feasible to scan dump cycle-by-cycle during program execution due to the excessive time required. In fact, it is not necessary to scan out the error-free states. In this paper, we introduce Suspect Window to cover the clock cycle in which the bug is triggered. Then, we present an efficient approach to determine the suspect window. Based on Suspect Window, we propose a novel debug mechanism to locate the bug both temporally and spatially. Since scan dumps are only taken in the suspect window with the proposed mechanism, the time required for locating the bug is greatly reduced. The approaches are evaluated using ISCAS'89 and ITC'99 benchmark circuits. The experimental results show that the proposed mechanism can significantly reduce the overall debug time compared to scan-based debug mechanism while keeping high observability. Copyright © 2010 The institute of Electronics, Information and Communication Engineers.

关键词： Observability

来源：评论

学校读者我要写书评

暂无评论

TMemCanal: A VM-oblivious dynamic memory optimization scheme for virtual machines in cloud computing

TMemCanal: A VM-oblivious dynamic memory optimization scheme...

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： Li, Yaqiong Huang, Yongbing Key Laboratory of Computer System and Architecture Institute of Computing Technology Chinese Academy of Sciences China Graduate University Chinese of Academy of Sciences China

ISBN: (纸本)9780769541082

In current virtualized cloud platforms, resource provisioning strategy is still a big challenge. Provisioning will gain low resource utilization based on peak workload, and provisioning based on average work loads will sacrifice the potential revenue of cloud customers because of bad user experiences. VM-based performance isolation also restrains resource flowing on demand. As to memory, this eventually results in under-loaded memory and over-loaded memory in the same data center. This paper proposes a VM-oblivious dynamic memory optimization scheme, TMemCanal, which leverages under-loaded memory in a data center to accommodate the needs of loaded memory dynamically in a transparent fashion. TMemCanal is able to identify the under-loaded memory located in different VMs and reuse it in a way of memory flowing without any modification to their Guest OSs. We implemented TMemCanal through extending Xen hypervisor and evaluated using SpecWeb 2005 and LinkPack Benchmarks. Our evaluation shows that TMemCanal can efficiently save memory up to 50% with an overhead less than 7%. Our case study of server consolidation also shows TMemCanal can promote the performance of memory-intensive services up to 400%. © 2010 IEEE.

关键词： Virtual machine

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：