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2011 International Conference on Electric Information and Control Engineering, ICEICE 2011

作者： Xia, Jiang Luan, Wenjing Department of Computer Laiwu Vocational and Technical College Laiwu 271100 China Key Laboratory of Embedded System and Service Computing Ministry of Education Tongji University Shanghai 200092 China College of Information Science and Engineering Shandong University of Science and Technology Qingdao 266510 China

A new book-lending system is designed and analyzed based on logic Petri nets in this paper. The batch processing function and indeterminacy of readers are included in the system. Its logic Petri net model is establish... 详细信息

ISBN: (纸本)9781424480395

关键词： Petri nets

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Memory Leak Detection Based on Memory State Transition Graph

Memory Leak Detection Based on Memory State Transition Graph

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Asia-Pacific Conference on software Engineering

作者： Zhenbo Xu Jian Zhang Zhongxing Xu Department of Computer Science and Technology University of Science and Technology of China China State Key Laboratory of Computer Science Institute of Software Chinese Academy of Sciences China

Memory leak is a common type of defect that is hard to detect manually. Existing memory leak detection tools suffer from lack of precise interprocedural alias and path conditions. To address this problem, we present a static interprocedural analysis algorithm, which captures memory actions and path conditions precisely, to detect memory leak in C programs. Our algorithm uses path-sensitive symbolic execution to track the memory actions in different program paths guarded by path conditions. A novel analysis model called Memory State Transition Graph (MSTG) is proposed to describe the tracking process and its results. An MSTG is generated from a procedure. Nodes in an MSTG contain states of memory objects which record the function behaviors precisely. Edges in anMSTG are annotated with path conditions collected by symbolic execution. The path conditions are checked for satisfiability to reduce the number of false alarms and the path explosion. In order to do interprocedural analysis, our algorithm generates a summary for each procedure from the MSTG and applies the summary at the procedure's call sites. Our implemented tool has found several memory leak bugs in some open source programs and detected more bugs than other tools in some programs from the SPEC2000 benchmarks. In some cases, our tool produces many false positives, but most of them are caused by the same code patterns which are easy to check.

关键词： computer bugs Algorithm design and analysis Analytical models Leak detection Detectors Resource management Explosions

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Fault analysis study of the block cipher FOX64

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Multimedia Tools and Applications 2011年第3期63卷 691-708页

作者： Li, Ruilin You, Jianxiong Sun, Bing Li, Chao Department of Mathematics and System Science Science College National University of Defense Technology Changsha China State Key Laboratory of Information Security Institute of Software Chinese Academy of Sciences Beijing China College of Computer National University of Defense Technology Changsha China

FOX is a family of symmetric block ciphers from MediaCrypt AG that helps to secure digital media, communications, and storage. The high-level structure of FOX is the so-called (extended) Lai–Massey scheme. This paper presents a detailed fault analysis of the block cipher FOX64, the 64-bit version of FOX, based on a differential property of two-round Lai–Massey scheme in a fault model. Previous fault attack on FOX64 shows that each round-key (resp. whole round-keys) could be recovered through 11.45 (resp. 183.20) faults on average. Our proposed fault attack, however, can deduce any round-key (except the first one) through 4.25 faults on average (4 in the best case), and retrieve the whole round-keys through 43.31 faults on average (38 in the best case). This implies that the number of needed faults in the fault attack on FOX64 can be significantly reduced. Furthermore, the technique introduced in this paper can be extended to other series of the block cipher family FOX.

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The hidden experts in software-engineering communication: NIER track

The hidden experts in software-engineering communication: NI...

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International Conference on software Engineering (ICSE)

作者： Irwin Kwan Daniela Damian Software Engineering Global InterAction Laboratory Department of Computer Science University of Victoria Victoria BC Canada

Sharing knowledge in a timely fashion is important in distributed software development. However, because experts are difficult to locate, developers tend to broadcast information to find the right people, which leads to overload and to communication breakdowns. We study the context in which experts are included in an email discussion so that team members can identify experts sooner. In this paper, we conduct a case study examining why people emerge in discussions by examining email within a distributed team. We find that people emerge in the following four situations: when a crisis occurs, when they respond to explicit requests, when they are forwarded in announcements, and when discussants follow up on a previous event such as a meeting. We observe that emergent people respond not only to situations where developers are seeking expertise, but also to execute routine tasks. Our findings have implications for expertise seeking and knowledge management processes.

关键词： Electronic mail Servers Programming Organizations Context

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SIMD Friendly Ray Tracing on GPU

SIMD Friendly Ray Tracing on GPU

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IEEE International Conference on computer-Aided Design and computer Graphics

作者： Peng Zhou Xiangxu Meng Department of Computer Science Shandong Provincial Key Laboratory of Software Engineering Shandong University Jinan China

In this paper, we present a novel BVH tracing method on GPU, which can achieve better SIMD utilization than traditional method. In the traditional way, thread usually sticks to a ray until the closest hit is found. When the threads of the same warp follow very divergent ray paths, SIMD utilization drops significantly. The idea of our method is to redefine the way of work distribution by binding the ray and the data to be tested together, in order to spread the computation of the single ray to multi threads. We also separate the tracing process into three steps to collect the work units of the same type and process them in a stream-like manner. The first step is ray traversal whose task is to do ray-box testing for the ray-node pairs. Its output is an stack of ray-triangle pairs, which is then fed to intersecting step to form an stack of ray-hit pairs. The last step is to use ray-hit pairs to update the closest hits for each ray of the same warp. The experiment shows our method can efficiently improve the SIMD utilization and result in less tracing time.

关键词： Arrays Graphics processing unit Instruction sets Indexes Kernel Ray tracing Sorting

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Network Recovery and Augmentation under Geographically Correlated Region Failures

Network Recovery and Augmentation under Geographically Corre...

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2011 IEEE Global Telecommunications Conference - GLOBECOM 2011

作者： Xiaoliang Wang State Key Laboratory of Novel Software Technology Department of Computer Science and Technology Nanjing University China

The network infrastructures are under the threat of large-scale disruptions, both natural (like earthquake, flooding) and intentional (like EMP attack, bomb explosion). In such scenarios, a number of network elements are likely to be destroyed simultaneously when they are intersected in a geographically correlated region, and thus may dramatically compromise the connectivity or even disconnect the network. In this paper we focus on the issue of providing continuous communication against region failure. We define two optimization problems: the first problem considers effective connection recovery when a disruptive event happens, and the second one studies network augmentation to build a resilient network against any single region failure. We prove that both problems are NP-hard, and then propose two heuristic algorithms to solve these optimization problems.

关键词： Approximation methods Approximation algorithms Peer to peer computing Greedy algorithms Mission critical systems Probabilistic logic Reliability

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3DV quality model based depth maps for view synthesis in FTV system

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Journal of Shanghai University(English Edition) 2011年第4期15卷 335-341页

作者：张秋闻安平张艳张兆杨王元庆 Key Laboratory of Advanced Display and System Application (Shanghai University) Ministry of EducationShanghai 200072P.R.China School of Communication and Information Engineering Shanghai University Department of Computer Science and Technology Anhui University of Finance and EconomicsBengbu 230030AuhuiP.R.China Department of Electronics Science and Engineering Nanjing University

Depth maps are used for synthesis virtual view in free-viewpoint television （FTV） systems. When depth maps are derived using existing depth estimation methods, the depth distortions will cause undesirable artifacts in the synthesized views. To solve this problem, a 3D video quality model base depth maps （D-3DV） for virtual view synthesis and depth map coding in the FTV applications is proposed. First, the relationships between distortions in coded depth map and rendered view are derived. Then, a precisely 3DV quality model based depth characteristics is develop for the synthesized virtual views. Finally, based on D-3DV model, a multilateral filtering is applied as a pre-processed filter to reduce rendering artifacts. The experimental results evaluated by objective and subjective methods indicate that the proposed D-3DV model can reduce bit-rate of depth coding and achieve better rendering quality.

关键词： free-viewpoint television （FTV） 3D video quality model base depth maps （D-3DV） view synthesis

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Evaluating the viability of process replication reliability for exascale systems

Evaluating the viability of process replication reliability ...

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Supercomputing Conference

作者： Kurt Ferreira Jon Stearley James H. Laros Ron Oldfield Kevin Pedretti Ron Brightwell Rolf Riesen Patrick G. Bridges Dorian Arnold Scalable System Software Department Sandia National Laboratories USA IBM Research Ireland Department of Computer Science University of New Mexico USA

As high-end computing machines continue to grow in size, issues such as fault tolerance and reliability limit application scalability. Current techniques to ensure progress across faults, like checkpoint-restart, are increasingly problematic at these scales due to excessive overheads predicted to more than double an application's time to solution. Replicated computing techniques, particularly state machine replication, long used in distributed and mission critical systems, have been suggested as an alternative to checkpoint-restart. In this paper, we evaluate the viability of using state machine replication as the primary fault tolerance mechanism for upcoming exascale systems. We use a combination of modeling, empirical analysis, and simulation to study the costs and benefits of this approach in comparison to check-point/restart on a wide range of system parameters. These results, which cover different failure distributions, hardware mean time to failures, and I/O bandwidths, show that state machine replication is a potentially useful technique for meeting the fault tolerance demands of HPC applications on future exascale platforms.

关键词： Protocols Hardware Fault tolerance Fault tolerant systems computer crashes Sockets Bandwidth

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Cross-platform wireless sensor network development

Cross-platform wireless sensor network development

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International Symposium on Information Processing in Sensor Networks (IPSN)

作者： Morten Tranberg Hansen Branislav Kusy Department of Computer Science Aarhus University Denmark Autonomous System Laboratory CSIRO ICT Centre Australia

Design and development of wireless sensor network applications adds an additional layer of complexity to traditional computer systems. The developer needs to be an expert in resource constrained embedded devices as well as traditional desktop computers. We propose Tinylnventor, an open-source development environment that takes a holistic approach to implementing sensor network applications. Users build applications using a drag-and-drop visual programming language Open Blocks, a language that Google selected for its App Inventor for Android. Tinylnventor uses cross-platform programming concepts, such as threads and common network operations, to provide a unified environment from which it generates application binaries for the respective platforms. We demonstrate through an application example that Tinylnventor is both simple to use and powerful in expressing complex applications.

关键词： Message systems Wireless sensor networks Programming Hardware Instruction sets Temperature sensors Base stations

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Unified broadcast in sensor networks

Unified broadcast in sensor networks

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International Symposium on Information Processing in Sensor Networks (IPSN)

作者： Morten Tranberg Hansen Raja Jurdak Branislav Kusy Department of Computer Science Aarhus University Denmark Autonomous System Laboratory CSIRO ICT Centre Australia

Complex sensor network applications include multiple services such as collection, dissemination, time synchronization, and failure detection protocols. Many of these protocols require local state maintenance through periodic broadcasts which leads to high control overhead. Recent attempts to consolidate these broadcasts focus on piggybacking information into existing services but such tight coupling between protocols limits code reuse and interoperability of applications. We present Unified Broadcast (UB) which combines broadcasts from multiple protocols while maintaining a modular architecture of the network stack. UB is implemented as a transparent layer between the link and network layers, where it delays, schedules, and combines broadcasts from upper layer protocols before transmission on the wireless channel. Our empirical results in simulation and on a testbed show that UB can decrease the overall packet transmissions in the network by more than 60%, corresponding to more than 40% energy savings, without requiring new interfaces or affecting the correctness of the upper layer protocols.

关键词： Protocols Delay Synchronization Wireless sensor networks Equations Proposals Monitoring

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