检索结果-内蒙古大学图书馆

20th IEEE International parallel and distributed Processing Symposium, IPDPS 2006

作者： Merkle, Daniel Middendorf, Martin Scheidler, Alexander Parallel Computing and Complex Systems Group Department of Computer Science University of Leipzig Augustusplatz 10/11 D-04109 Leipzig Germany

ISBN: (纸本)1424400546

A self-organized allocation scheme for service tasks in computing systems is proposed in this paper. Usually components of a computing system need some service from time to time in order perform their work efficiently. In adaptive computing systems the components and the necessary tasks adapt to the needs of users or the environment. Since in such cases the type of service tasks will often change it is attractive to use reconfigurable hardware to perform the service tasks. The studied system consists of normal worker components and helper components which have reconfigurable hardware and can perform different service tasks. The speed with which a service tasks is executed by a helper depends on its actual configuration. Different strategies for the helpers to decide about service task acceptance and reconfiguration are proposed. These strategies are inspired by stimulus-threshold models that are used to explain task allocation in social insects. © 2006 IEEE.

关键词： Resource allocation

来源：评论

学校读者我要写书评

暂无评论

Tinman: Eliminating confidential mobile data exposure with security oriented offloading 15

Tinman: Eliminating confidential mobile data exposure with s...

引用

10th European Conference on computer systems, EuroSys 2015

作者： Xia, Yubin Liu, Yutao Tan, Cheng Ma, Mingyang Guan, Haibing Zang, Binyu Chen, Haibo Shanghai Key Laboratory of Scalable Computing and Systems China Institute of Parallel and Distributed Systems Shanghai Jiao Tong University China Department of Computer Science Shanghai Jiao Tong University China

ISBN: (纸本)9781450332385

The wide adoption of smart devices has stimulated a fast shift of security-critical data from desktop to mobile devices. However, recurrent device theft and loss expose mobile devices to various security threats and even physical attacks. This paper presents TinMan, a system that protects confidential data such as web site password and credit card number (we use the term cor to represent these data, which is short for Confidential Record) from being leaked or abused even under device theft. TinMan separates accesses of cor from the rest of the functionalities of an app, by introducing a trusted node to store cor and offloading any code from a mobile device to the trusted node to access cor. This completely eliminates the exposure of cor on the mobile devices. The key challenges to TinMan include deciding when and how to efficiently and transparently offload execution;Tin-Man addresses these challenges with security-oriented offloading with a low-overhead tainting scheme called asymmetric tainting to track accesses to cor to trigger offloading, as well as transparent SSL session injection and TCP payload replacement to offload accesses to cor. We have implemented a prototype of TinMan based on Android and demonstrated how TinMan protects the information of user's bank account and credit card number without modifying the apps. Evaluation results also show that TinMan incurs only a small amount of performance and power overhead. Copyright © 2015 ACM.

关键词： Crime

来源：评论

学校读者我要写书评

暂无评论

Flexible particle swarm optimization tasks for reconfigurable processor arrays

Flexible particle swarm optimization tasks for reconfigurabl...

引用

19th IEEE International parallel and distributed Processing Symposium, IPDPS 2005

作者： Janson, Stefan Middendorf, Martin Parallel Computing and Complex Systems Group Department of Computer Science University of Leipzig Augustusplatz 10/11 D-04109 Leipzig Germany

ISBN: (纸本)0769523129

Multi task parallel processor arrays are a common machine architecture in which, typically, the tasks running in parallel occupy disjoint subarrays of the machine. On dynamically and partially reconfigurable processor arrays the tasks can be changed during run time. This is useful for online scenarios when the relative importance of tasks might change and therefore the assignment of computational resources to the tasks should be changed. Examples are optimization tasks in an online scenario in which the results of some tasks are needed earlier than expected at initialization. For such tasks the size of their subarrays must be increased because they need more computational resources to speed up. In this paper we design flexible Particle Swarm Optimization (PSO) algorithms for 2-dimensional reconfigurable processor arrays where the algorithms can change their size and have a good optimization behaviour. Since PSO is an iterative, individual-based optimization algorithm that relies upon interactions of neighbouring particles suitable for fine-grained parallel architectures. We propose a dynamic 2-dimensional hierarchical ordering of the particles within a tasks subarray so that the best particles are concentrated in the center. This gives the best particles the strongest influence on the swarm. A further advantage is that size reductions of the tasks can easily be done by cutting off the outer parts of the swarm which contain mainly the less good particles. It is experimentally shown that the proposed algorithms perform better than standard PSO algorithms under conditions with varying supply of computing resources that are available for the tasks. Moreover, also for conditions with constant supply of processing resources and no need for size changes the proposed algorithms perform well.

关键词： Arrays

来源：评论

学校读者我要写书评

暂无评论

Selected Recent Applications of Sparse Grids

引用

Numerical Mathematics(Theory,Methods and Applications) 2015年第1期8卷 47-77页

作者： Benjamin Peherstorfer Christoph Kowitz Dirk Pfluger Hans-Joachim Bungartz Scientific Computing Group Dept.of Computer ScienceBoltzmannstr.385748 GarchingGermany Institutefor Advanced Study Technische UniversitätMünchenLichtenbergstr.2a85748 GarchingGermany Institute for Parallel and Distributed Systems University of StuttgartUni-versitätsstr.3870569 StuttgartGermany

Sparse grids have become a versatile tool for a vast range of applications reaching from interpolation and numerical quadrature to data-driven problems and uncertainty *** review four selected real-world applications of sparse grids:financial product pricing with the Black-Scholes model,interactive explo-ration of simulation data with sparse-grid-based surrogate models,analysis of simu-lation data through sparse grid data mining methods,and stability investigations of plasma turbulence simulations.

关键词： Sparse grids hierarchical decomposition adaptivity combination technique

来源：评论

学校读者我要写书评

暂无评论

A parameter-adaptive dynamic programming approach for inferring cophylogenies

A parameter-adaptive dynamic programming approach for inferr...

引用

8th Asia-Pacific Bioinformatics Conference, APBC 2010

作者： Merkle, Daniel Middendorf, Martin Wieseke, Nicolas Department of Mathematics and Computer Science University of Southern Denmark Odense Denmark Parallel Computing and Complex Systems Group Department of Computer Science University of Leipzig Germany

Background: Coevolutionary systems like hosts and their parasites are commonly used model systems for evolutionary studies. Inferring the coevolutionary history based on given phylogenies of both groups is often done by employing a set of possible types of events that happened during coevolution. Costs are assigned to the different types of events and a reconstruction of the common history with a minimal sum of event costs is sought. Results: This paper introduces a new algorithm and a corresponding tool called CoRe-PA, that can be used to infer the common history of coevolutionary systems. The proposed method utilizes an event-based concept for reconciliation analyses where the possible events are cospeciations, sortings, duplications, and (host) switches. All known event-based approaches so far assign costs to each type of cophylogenetic events in order to find a cost-minimal reconstruction. CoRe-PA uses a new parameter-adaptive approach, i.e., no costs have to be assigned to the coevolutionary events in advance. Several biological coevolutionary systems that have already been studied intensely in literature are used to show the performance of CoRe-PA. Conclusion: From a biological point of view reasonable cost values for event-based reconciliations can often be estimated only very roughly. CoRe-PA is very useful when it is difficult or impossible to assign exact cost values to different types of coevolutionary events in advance. © 2010 Yeturu et al;licensee BioMed Central Ltd.

关键词： Costs

来源：评论

学校读者我要写书评

暂无评论

A comparison of the Iserver-Occam, Parix, Express, and PVM programming environments on a parsytec GCel

A comparison of the Iserver-Occam, Parix, Express, and PVM p...

引用

International Conference and Exhibition on High-Performance Computing and Networking, HPCN 1994

作者： Sloot, P.M.A. Hoekstra, A.G. Hertzberger, L.O. Parallel Scientific Computing & Simulation Group Department of Computer Systems Faculty of Mathematics and Computer Science University of Amsterdam Kruislaan 403 Amsterdam1098 SJ Netherlands

ISBN: (纸本)9783540579816

We compare the Iserver-Occam, Parix, PVM, and Express parallel programming environments on a Parsytec GCel with 512 T805 transputers. The comparison will be made by a detailed analysis of the performance of one particular application. In our approach we start with this application and isolate the basic (environment dependent) building blocks. These basic building blocks, which depend on floating point performance and communication capabilities of the environments, are analysed independently. We have measured point to point communication times, global communication times and floating point performance. All information will be combined into a time complexity analysis, allowing us to compare the environments on all relevant degrees of functionality. Together with demands for portability of the code, and development time (i.e. programmability), an overall judgement of the environments can be made. © 1994, Springer Verlag. All rights reserved.

关键词： Transputers

来源：评论

学校读者我要写书评

暂无评论

Finding All sorting tandem duplication random loss operations

引用

20th Annual Symposium on Combinatorial Pattern Matching, CPM 2009

作者： Bernt, Matthias Chen, Ming-Chiang Merkle, Daniel Wang, Hung-Lung Chao, Kun-Mao Middendorf, Martin Parallel Computing and Complex Systems Group Department of Computer Science University of Leipzig Germany Department of Computer Science and Information Engineering National Taiwan University Taiwan Department of Mathematics and Computer Science University of Southern Denmark Odense Denmark

ISBN: (纸本)3642024408

A tandem duplication random loss (TDRL) operation duplicates a contiguous segment of genes, followed by the loss of one copy of each of the duplicated genes. Although the importance of this operation is founded by several recent biological studies, it has been investigated only rarely from a theoretical point of view. Of particular interest are sorting TDRLs which are TDRLs that, when applied to a permutation representing a genome, reduce the distance towards another given permutation. The identification of sorting genome rearrangement operations in general is a key ingredient of many algorithms for reconstructing the evolutionary history of a set of species. In this paper we present methods to compute all sorting TDRLs for two given gene orders. In addition, a closed formula for the number of sorting TDRLs is derived and further properties of sorting TDRLs are investigated. It is also shown that the theoretical findings are useful for identifying unique sorting TDRL scenarios for mitochondrial gene orders. © 2009 Springer Berlin Heidelberg.

关键词： Genes

来源：评论

学校读者我要写书评

暂无评论

Making cost-based query optimization asymmetry-aware

Making cost-based query optimization asymmetry-aware

引用

8th International Workshop on Data Management on New Hardware, DaMoN 2012 - In Conjunction with ACM SIGMOD/PODS Conference

作者： Bausch, Daniel Petrov, Ilia Buchmann, Alejandro Technische Universität Darmstadt Department of Computer Science Databases and Distributed Systems Group Hochschulstraße 10 64289 Darmstadt Germany

ISBN: (纸本)9781450314459

The architecture and algorithms of database systems have been built around the properties of existing hardware technologies. Many such elementary design assumptions are 20 - 30 years old. Over the last five years we witness multiple new I/O technologies (e.g. Flash SSDs, NV-Memories) that have the potential of changing these assumptions. Some of the key technological differences to traditional spinning disk storage are: (i) asymmetric read/write performance;(ii) low latencies;(iii) fast random reads;(iv) endurance issues. Cost functions used by traditional database query optimizers are directly influenced by these properties. Most cost functions estimate the cost of algorithms based on metrics such as sequential and random I/O costs besides CPU and memory consumption. These do not account for asymmetry or high random read and inferior random write performance, which represents a significant mismatch. In the present paper we show a new asymmetry-aware cost model for Flash SSDs with adapted cost functions for algorithms such as external sort, hash-join, sequential scan, index scan, etc. It has been implemented in PostgreSQL and tested with TPC-H. Additionally we describe a tool that automatically finds good settings for the base coefficients of cost models. After tuning the configuration of both the original and the asymmetry-aware cost model with that tool, the optimizer with the asymmetry-aware cost model selects faster execution plans for 14 out of the 22 TPC-H queries (the rest being the same or negligibly worse). We achieve an overall performance improvement of 48% on SSD. © 2012 ACM.

关键词： Cost functions

来源：评论

学校读者我要写书评

暂无评论

Optimal scheduling of iterative data-flow programs onto multiprocessors with non-negligible interprocessor communication 7th

Optimal scheduling of iterative data-flow programs onto mult...

引用

7th International Conference on High-Performance Computing and Networking, HPCN Europe 1999

作者： Antony Louis Piriyakumar, D. Levi, Paul Siva Ram Murthy, C. Institute of Parallel and Distributed High-Performance Systems University of Stuttgart Stuttgart70565 Germany Department of Computer Science and Engineering Indian Institute of Technology Chennai600 036 India

ISBN: (纸本)3540658211

The problem of optimal compile-time multiprocessor scheduling of iterative data-flow programs with feedback (delay elements) is addressed in this paper, unlike the earlier studies assumed the availability of a large number of processors and complete interconnection among them along with the interprocessor communication (IPC) to be non-negligible to be more realistic. We first explain the effects of including IPC in non-overlapped, overlapped, fully-static, and cyclo-static multiprocessor schedules with LMS filter as a realistic example. The effect of IPC in the rate-optimal schedules with the transformation techniques viz. unfolding and retiming in scheduling data-flow programs with optimal unfolding is discussed with an example. We then propose an algorithm, based on the well-known A* algorithm, for optimal scheduling of data-flow programs onto multiprocessors, which uses only minimum number of processors. To alleviate the impediments of large requirements of memory space and CPU time for the optimal scheduling algorithm, we present an effective technique, branch join path isomorphism (BJP) which relies on our previously defined processor isomorphism, task isomorphism, and node isomorphism apart from the lower bound theory and upper bound on the completion time. The schedules produced by our algorithm are superior to those obtained by the earlier algorithms despite considering IPC as non-negligible and also not completely connected multiprocessor systems. © Springer-Verlag Berlin Heidelberg 1999.

关键词： Scheduling

来源：评论

学校读者我要写书评

暂无评论

A dynamic negotiation framework for mobile agents 1

A dynamic negotiation framework for mobile agents

引用

1st International Symposium on Agent systems and Applications and 3rd International Symposium on Mobile Agents, ASA/MA 1999

作者： Tu, M.T. Seebode, C. Lamersdorf, W. Computer Science Department University of Hamburg Distributed Systems Group Vogt-Kölln-Str. 30 Hamburg22527 Germany

ISBN: (纸本)0769503403

In this paper, a framework to integrate negotiation capabilities - particularly components implementing a negotiation strategy - into mobile agents is introduced. The framework is based on a plug-in mechanism enabling a dynamic composition of negotiating agents out of pluggable modules. Strategy modules are further decomposed into parallel execution units based on the notion of an actor system.

关键词： Mobile agents

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：