Int. J. Netw. Comput.最新文献_第8页

An Active Access-Point Configuration Algorithm for Elastic Wireless Local-Area Network System Using Heterogeneous Devices 基于异构设备的弹性无线局域网系统的主动接入点配置算法

Int. J. Netw. Comput. Pub Date : 2016-07-25 DOI: 10.15803/IJNC.6.2_395

Md. Selim Al Mamun, Md. Ezharul Islam, N. Funabiki, M. Kuribayashi, I-Wei Lai

{"title":"An Active Access-Point Configuration Algorithm for Elastic Wireless Local-Area Network System Using Heterogeneous Devices","authors":"Md. Selim Al Mamun, Md. Ezharul Islam, N. Funabiki, M. Kuribayashi, I-Wei Lai","doi":"10.15803/IJNC.6.2_395","DOIUrl":"https://doi.org/10.15803/IJNC.6.2_395","url":null,"abstract":"An Elastic Wireless Local-Area Network (WLAN) system provides a reliable, flexible, and efficient Internet access to users through installations of heterogeneous access points (APs) including dedicated APs (DAPs), virtual APs (VAPs), and mobile APs (MAPs). The number of APs should be carefully selected to optimize the network performance. Specifically, for heavy traffic, a large number of APs are required. However, the dense deployment of APs introduces the inter-AP interferences which may eventually degrade the communication quality when the number of users are few. In this paper, we propose an {em active access-point configuration algorithm} that activates or deactivates APs according to the changes of network topologies and demands of users for the elastic WLAN system. The algorithm considers the bandwidth difference among heterogeneous AP devices and the total available bandwidth in the network. The number of active APs is minimized to ensure the minimum inter-AP interference subject to the constraints. The host locations can be the candidate positions for the MAPs, because host owners may use them for the Internet access. The effectiveness of the proposed algorithm is demonstrated using the WIMNET simulator.","PeriodicalId":270166,"journal":{"name":"Int. J. Netw. Comput.","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133085727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 19

A Performance Evaluation of Dynamic Parallelism for Fine-Grained, Irregular Workloads 细粒度、不规则工作负载的动态并行性性能评估

Int. J. Netw. Comput. Pub Date : 2016-07-25 DOI: 10.15803/IJNC.6.2_212

Max Plauth, Frank Feinbube, F. Schlegel, A. Polze

{"title":"A Performance Evaluation of Dynamic Parallelism for Fine-Grained, Irregular Workloads","authors":"Max Plauth, Frank Feinbube, F. Schlegel, A. Polze","doi":"10.15803/IJNC.6.2_212","DOIUrl":"https://doi.org/10.15803/IJNC.6.2_212","url":null,"abstract":"GPU compute devices have become very popular for general purpose computations. However, the SIMD-like hardware of graphics processors is currently not well suited for irregular workloads, like searching unbalanced trees. In order to mitigate this drawback, NVIDIA introduced an extension to GPU programming models called Dynamic Parallelism. This extension enables GPU programs to spawn new units of work directly on the GPU, allowing the refinement of subsequent work items based on intermediate results without any involvement of the main CPU. This work investigates methods for employing Dynamic Parallelism with the goal of improved workload distribution for tree search algorithms on modern GPU hardware. For the evaluation of the proposed approaches, a case study is conducted on the N-Queens problem. Extensive benchmarks indicate that the benefits of improved resource utilization fail to outweigh high management overhead and runtime limitations due to the very fine level of granularity of the investigated problem. However, novel memory management concepts for passing parameters to child grids are presented. These general concepts are applicable to other, more coarse-grained problems that benefit from the use of Dynamic Parallelism.","PeriodicalId":270166,"journal":{"name":"Int. J. Netw. Comput.","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127568242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 9

Routing and Broadcasting Algorithms for Generalized-Star Cube 广义星形立方体的路由和广播算法

Int. J. Netw. Comput. Pub Date : 2016-07-25 DOI: 10.15803/IJNC.6.2_368

Daiki Arai, Yamin Li

引用次数: 1

Web-based Volunteer Computing for Solving the Elliptic Curve Discrete Logarithm Problem 基于web的志愿计算求解椭圆曲线离散对数问题

Int. J. Netw. Comput. Pub Date : 2016-07-25 DOI: 10.15803/IJNC.6.2_181

Shoma Kajitani, Y. Nogami, Shunsuke Miyoshi, Thomas H. Austin, Md. Al-Amin Khandaker, Nasima Begum, S. Duquesne

引用次数: 1

A Memory-Efficient Implementation of a Plasmonics Simulation Application on SX-ACE SX-ACE上等离子体仿真应用的内存高效实现

Int. J. Netw. Comput. Pub Date : 2016-07-25 DOI: 10.15803/IJNC.6.2_243

R. Mathur, Hiroshi Matsuoka, Osamu Watanabe, A. Musa, Ryusuke Egawa, Hiroaki Kobayashi

{"title":"A Memory-Efficient Implementation of a Plasmonics Simulation Application on SX-ACE","authors":"R. Mathur, Hiroshi Matsuoka, Osamu Watanabe, A. Musa, Ryusuke Egawa, Hiroaki Kobayashi","doi":"10.15803/IJNC.6.2_243","DOIUrl":"https://doi.org/10.15803/IJNC.6.2_243","url":null,"abstract":"Since recent scientific and engineering simulations require heavy computations with large volumes of data, High-performance Computing (HPC) systems need a high computational capability with a large memory capacity. Most recent HPC systems adopt a parallel processing architecture, where the computational capability of the processors is increasing, however, the performance of the memory system is constrained. The bytes per flop (B/F), which is a ratio of the memory bandwidth to the flop/s, for the HPC systems have been reduced with the evolution of the HPC systems. To fully exploit the potential of the recent HPC systems, and to meet the increasing demand for large memory, it is necessary to optimize practical scientific and engineering applications, considering not only the parallelism of the applications, but also the limitations of the memory subsystems of the HPC systems. In this paper, we discuss a set of approaches to optimization of the memory access behavior of the applications, which enable their executions with improved performance on the recent HPC systems. Our approaches include memory optimizations through memory footprint controlling, restructuring of data structures for active elements, redundant data structure elimination through combined calculations and optimized re-calculation of data. To validate the effectiveness of our approaches, a plasmonics simulation application is evaluated on vector platforms NEC SX-ACE, NEC SX-9, and Intel Xeon based platform NEC LX 406-Re2. By applying our approaches to the implementation, the memory usage of the plasmonics simulation application can be reduced up to nearly 1/71 of the original, and its execution can be possible on a single node of a distributed parallel system with smaller memory capacity. The optimization results in 1.14 times faster execution on SX-ACE and 1.81 times faster execution on LX 406-Re2.","PeriodicalId":270166,"journal":{"name":"Int. J. Netw. Comput.","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129840831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Analysis of a method for constructing a cellular automaton from a continuous system 分析从连续系统构造元胞自动机的方法

Int. J. Netw. Comput. Pub Date : 2016-07-25 DOI: 10.15803/IJNC.6.2_230

Akane Kawaharada, T. Miyaji, Naoto Nakano

引用次数: 0

Translation of Large-Scale Simulation Codes for an OpenACC Platform Using the Xevolver Framework 基于Xevolver框架的OpenACC平台大规模仿真代码翻译

Int. J. Netw. Comput. Pub Date : 2016-07-25 DOI: 10.15803/IJNC.6.2_167

K. Komatsu, Ryusuke Egawa, S. Hirasawa, H. Takizawa, K. Itakura, Hiroaki Kobayashi

{"title":"Translation of Large-Scale Simulation Codes for an OpenACC Platform Using the Xevolver Framework","authors":"K. Komatsu, Ryusuke Egawa, S. Hirasawa, H. Takizawa, K. Itakura, Hiroaki Kobayashi","doi":"10.15803/IJNC.6.2_167","DOIUrl":"https://doi.org/10.15803/IJNC.6.2_167","url":null,"abstract":"As the diversity of high-performance computing (HPC) systems increases, even legacy HPC applications often need to use accelerators for higher performance. To migrate large-scale legacy HPC applications to modern HPC systems equipped with accelerators, a promising way is to use OpenACC because its directive-based approach can prevent drastic code modifications. This paper shows translation of a large-scale simulation code for an OpenACC platform by keeping the maintainability of the original code. Although OpenACC enables an application to use accelerators by adding a small number of directives, it requires modifying the original code to achieve a high performance in most cases, which tends to degrade the code maintainability and performance portability. To avoid such code modifications, this paper adopts a code translation framework, Xevolver. Instead of directly modifying a code, a pair of a custom code translation rule and a custom directive is defined, and is applied to the original code using the Xevolver framework. This paper first shows that simply inserting OpenACC directives does not lead to high performance and non-trivial code modifications are required in practice. In addition, the code modifications sometimes decrease the performance when migrating a code to other platforms, which leads to low performance portability. Â The direct code modifications can be avoided by using pairs of an externally-defined translation rule and a custom directive to keep the original code unchanged as much as possible. Finally, the performance evaluation shows that the performance portability can be improved by selectively applying translation with the Xevolver framework compared with directly modifying a code.","PeriodicalId":270166,"journal":{"name":"Int. J. Netw. Comput.","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132461020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6

Preface: Special issue on the Third International Symposium on Computing and Networking 前言:第三届计算与网络国际研讨会特刊

Int. J. Netw. Comput. Pub Date : 2016-07-25 DOI: 10.15803/IJNC.6.2_148

K. Nakano

{"title":"Preface: Special issue on the Third International Symposium on Computing and Networking","authors":"K. Nakano","doi":"10.15803/IJNC.6.2_148","DOIUrl":"https://doi.org/10.15803/IJNC.6.2_148","url":null,"abstract":"The Third International Symposium on Networking and Computing (CANDAR 2015) was held in Sapporo, Japan, from December 8th to 11th, 2015. The organizers of the CANDAR 2015 invited authors to submit the extended version of the presented papers. As a result, 22 articles have been submitted to this special issue. This issue includes the extended version of 14 papers that have been accepted. This issue owes a great deal to a number of people who devoted their time and expertise to handle the submitted papers. In particular, I would like to thank the guest editors for the excellent review process: Professor Satoshi Fujita, Professor Akihiro Fujiwara, Professor Nobuo Funabiki, Professor Shuichi Ichikawa, Professor Katsunobu Imai, Professor Yoshiaki Kakuda, Professor Michihiro Koibuchi, Professor Kazuhiko Komatsu, Professor Shirley Moore, Professor Toru Nakanishi, Professor Yasuyuki Nogami, Professor Tomoyuki Ohta, Professor Ferdinand Peper, Professor Hiroyuki Sato, Professor Reiji Suda, Professor Hiroyuki Takizawa, and Professor Takashi Yokota. Words of gratitude are also due to the anonymous reviewers who carefully read the papers and provided detailed comments and suggestions to improve the quality of the submitted papers. This special issue would not have been without their efforts.","PeriodicalId":270166,"journal":{"name":"Int. J. Netw. Comput.","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125957965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Bulk execution of Euclidean algorithms on the CUDA-enabled GPU 在支持cuda的GPU上批量执行欧几里得算法

Int. J. Netw. Comput. Pub Date : 2016-01-12 DOI: 10.15803/IJNC.6.1_42

Toru Fujita, K. Nakano, Yasuaki Ito

{"title":"Bulk execution of Euclidean algorithms on the CUDA-enabled GPU","authors":"Toru Fujita, K. Nakano, Yasuaki Ito","doi":"10.15803/IJNC.6.1_42","DOIUrl":"https://doi.org/10.15803/IJNC.6.1_42","url":null,"abstract":"The bulk execution of a sequential algorithm is to execute it for many different inputs in turn or at the same time. A sequential algorithm is oblivious if the address accessed at each time unit is independent of the input. It is known that the bulk execution of an oblivious sequential algorithm can be implemented to run on a GPU very efficiently. The main purpose of our work is to implement the bulk execution of a Euclidean algorithm computing the GCD (Greatest Common Divisor) of two large numbers in a GPU. We first present a new efficient Euclidean algorithm that we call the Approximate Euclidean algorithm. The idea of the Approximate Euclidean algorithm is to compute an approximation of quotient by just one 64-bit division and to use it for reducing the number of iterations of the Euclidean algorithm. Unfortunately, the Approximate Euclidean algorithm is not oblivious. To show that the bulk execution of the Approximate Euclidean algorithm can be implemented efficiently in the GPU, we introduce a semi-oblivious sequential algorithms, which is almost oblivious. We show that the Approximate Euclidean algorithm can be implemented as a semi-oblivious algorithm. The experimental results show that our parallel implementation of the Approximate Euclidean algorithm for 1024- bit integers running on GeForce GTX Titan X GPU is 90 times faster than the Intel Xeon CPU implementation.Â","PeriodicalId":270166,"journal":{"name":"Int. J. Netw. Comput.","volume":"213 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120838965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Efficient Multicore Algorithms For Identifying Biconnected Components 识别双连接组件的高效多核算法

Int. J. Netw. Comput. Pub Date : 2016-01-12 DOI: 10.15803/IJNC.6.1_87

Meher Chaitanya, Kishore Kothapalli

引用次数: 14