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International Conference on distributed Computing systems Workshop

作者： Qi Li Mingwei Xu Xinwen Zhang Department of Computer Science Tsinghua University Beijing China Tsinghua National Laboratory for Information Science and Technology Beijing China Samsung Information Systems America Inc. San Jose CA USA

ISBN: (纸本)9781424431755

Role-based Access Control (RBAC) has been widely deployed in many distributed systems in recent years. However, in many large-scale enterprise environments, it is difficult to manage RBAC because of the huge number of users and roles, and complex interrelationships between them. Moreover, with the development of information and communication technologies, many temporal and ad hoc collaborations between groups and departments are emerging, which require dynamic user-role and permission-role assignments. In these scenarios it is infeasible, if not impossible, for few security officers to administrate the assignment for various applications. In this paper, we propose a novel RBAC model for decentralized and distributed systems. As one of the main contributions, we also propose a decentralized administration model to address the management issues in traditional RBAC systems, Our model can be used for group-based applications with dynamic assignments where typically local (group-level) administrators take charge of the dynamic assignments. In this way, many administrative tasks for different applications can spread over many different local administrators, and a fine-grained administration model of RBAC based on the local administration policies is realized. As a proof-of-concept system, we implemented a secure Spread prototype based on our proposed model to show the feasibility in the real applications.

关键词： Collaboration Task analysis Prototypes Information and communication technology Authorization

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Automatic Compliance of Privacy Policies in Federated Digital Identity Management

Automatic Compliance of Privacy Policies in Federated Digita...

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International Workshop on Policies for distributed systems and Networks

作者： Anna Squicciarini Marco Casassa Mont Abhilasha Bhargav-Spantzel Elisa Bertino Information Sciences Technology Pennsylvania State University USA Systems Security Laboratory Hewlett Packard Laboratories USA Intel Corporation USA Computer Science Department Purdue University USA

ISBN: (纸本)9780769531335

Privacy [4] in the digital world is an important problem which is becoming even more pressing as new collaborative applications are developed. The lack of privacy preserving mechanisms is particularly problematic in federated identity management contexts. In such a context, users can seamlessly interact with a variety of federated web services, through the use of single-sign-on mechanisms and the capability of sharing personal data among these web services. We argue that comprehensive privacy policies should be stated by federated service providers and proactively checked by these providers, before disclosing users' data to federated partners. To address such requirements, we introduce mechanisms and algorithms for policy compliance checking between federated service providers, based on an innovative policy subsumption approach. We formally introduce and analyze our approach.

关键词： Identity management systems Data privacy Data handling Conferences computer network management technology management Laboratories computer security Information security computer science

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Data-driven protocol off-loading for Ad hoc networking environment

Data-driven protocol off-loading for Ad hoc networking envir...

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2008 International Conference on Parallel and distributed Processing Techniques and Applications, PDPTA 2008

作者： Aoki, Kazuhiro Ishii, Hiroshi Mizuno, Osamu Iwata, Makoto Nishikawa, Hiroaki Information Infrastructure Laboratory Inc. Saiki 210-4 Tsukuba Ibaraki 300-0028 Japan School of Information Science and Technology Tokai University Kitakaname 1117 Hiratsuka Kanagawa 259-1292 Japan NTT Information Sharing Platform Laboratories Midori-cho 3-9-11 Musashino Tokyo 180-8585 Japan Department of Information System Engineering Kochi University of Technology Tosayamada-cho Miyanokuchi 185 Kami Kochi 782-8502 Japan Department of Computer Science Graduate School of Systems and Information Engineering University of Tsukuba Ten'nodai 1-1-1 Tsukuba Ibaraki 305-8573 Japan

ISBN: (纸本)1601320841

Pervasive networking environment as social infrastructure has been going to become a reality, especially through the recent considerable progress of semiconductor technology. Considering the case where next generation of pervasive networking is realized over ad hoc network suitable for emergency and some tentative event, some ofauthors study about an data- driven imprementation of Ad hoc and ubiquitous communication environment. It is very important to implement effective protocol handling and routing process in Ad hoc networking environment especially. This paper describes the effectiveness ofan implementation ofprotocol off-loader using networking-oriented data-driven processors CUE (Coordinating User's requirements and Engineering constraints). In Ad hoc network, it is necessary to realize connection-less protocol such as UDP/IPfor flexible routing and realtime communication. Firstly, this paper discusses data- driven implementation ofprotocol off-loader on CUE networking board to minimize overheads in protocol handling. Then this paper describes architecture of CUE-v2/CUE-v3 which is available version in CUE processors. This paper finally discusses effectiveness ofprotocol handling off-loader using CUE processor system. It shows that data-driven protocol off-loader can keep minimum turn-around time without runtime overheads.

关键词： Ad hoc networks

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Collaborative search in large-scale unstructured peer-to-peer networks

Collaborative search in large-scale unstructured peer-to-pee...

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36th International Conference on Parallel Processing in Xi'an, ICPP

作者： Zhang, Yiming Li, Dongsheng Chen, Lei Lu, Xicheng National Laboratory for Parallel and Distributed Processing NUDT Department of Computer Science Hong Kong University of Science and Technology

ISBN: (纸本)076952933X

Searching in large-scale unstructured peer-to-peer networks is challenging due to the lack of effective hint information to guide queries. In this paper, we propose POP, a Parallel, cOllaborative and Probabilistic search mechanism, in which query messages are viewed as search units to collaborate with each other and aggregate the distributed hints during the search process. A scheme called distributed Bloom Filter (DBF) is presented to propagate the hints with a bandwidth-aware manner, in which a node divides the received Bloom filter vector into subvectors and disseminates the fragments to its neighbors according to their bandwidth capacity. The effectiveness of POP is demonstrated through theoretical analysis and extensive simulations. © 2007 IEEE.

关键词： Bandwidth

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A grid based e-Research platform for clinical management in the human respiratory and vascular system

Conferences in Research and Practice in Information Technolo...

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Conferences in Research and Practice in Information technology Series 2007年 68卷 11-17页

作者： Cheung, Sherman Chu, Xingchen Xu, Shengjin Buyya, Rajkumar Tu, Jiyuan School of Aerospace Mechanical and Manufacturing Engineering RMIT University VIC 3083 Australia Grid Computing and Distributed Systems Laboratory Department of Computer Science and Software Engineering The University of Melbourne VIC 3010 Australia

ISBN: (纸本)192068249X

A Grid based e-Research platform is being developed for providing a simulation-based virtual reality environment for clinical management and therapy treatment. The development of this platform involves cross-disciplinary experts aiming at combining the state-of-the-art Computational Fluid Dynamics (CFD) analysis tools into clinical management system. These fluid dynamic studies support the physician and surgeon with recommendations for the possible range of treatment and operation techniques. The platform will consist of a cluster of computing nodes, a middleware (Grid management layer), internet accessible tomography data and CFD analysis tools, and a tailored graphical user interface (GUI) application for various experts. In future, this platform will provide the novel creation of a prototype virtual reality model environment that links each technical modular consisting of a consolidation system with flexible interface model for exchanging data efficiently. Furthermore, besides allowing expeditious sharing of data and analytical tools, it will also furnish a foundation for cross-disciplinary collaboration and will definitely foster further advancement of related biomechanics researches. © 2007, Australian computer Society, Inc.

关键词： Grid computing

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Collaborative Search in Large-scale Unstructured Peer-to-Peer Networks

Collaborative Search in Large-scale Unstructured Peer-to-Pee...

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International Conference on Parallel Processing (ICPP)

作者： Yiming Zhang Dongsheng Li Lei Chen Xicheng Lu National Laboratory for Parallel and Distributed Processing National University of Defense Technology China Department of Computer Science Hong Kong University of Science and Technology Hong Kong China

Searching in large-scale unstructured peer-to-peer networks is challenging due to the lack of effective hint information to guide queries. In this paper, we propose POP, a Parallel, collaborative and Probabilistic search mechanism, in which query messages are viewed as search units to collaborate with each other and aggregate the distributed hints during the search process. A scheme called distributed Bloom filter (DBF) is presented to propagate the hints with a bandwidth-aware manner, in which a node divides the received Bloom filter vector into subvectors and disseminates the fragments to its neighbors according to their bandwidth capacity. The effectiveness of POP is demonstrated through theoretical analysis and extensive simulations.

关键词： Large-scale systems Peer to peer computing Bandwidth Information filtering Information filters Analytical models Aggregates Space technology International collaboration Laboratories

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Rate allocation for multi-user video streaming over heterogenous access networks

Rate allocation for multi-user video streaming over heteroge...

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15th ACM International Conference on Multimedia, MM'07

作者： Zhu, Xiaoqing Agrawal, Piyush Pal Singh, Jatinder Alpcan, Tansu Girod, Bernd Information Systems Laboratory Stanford University Stanford CA 94305 United States Department of Computer Science and Engineering Indian Institute of Technology Kanpur India Deutsche Telekom Laboratories Technische Universitat Berlin Ernst-Reuter Platz 7 10587 Germany

ISBN: (纸本)9781595937025

Contemporary wireless devices integrate multiple networking technologies, such as cellular, WiMax and IEEE 802.11a/b/g, as alternative means of accessing the Internet. Efficient utilization of available bandwidth over heterogeneous access networks is important, especially for media streaming applications with high data rates and stringent delay requirements. In this work we consider the problem of rate allocation among multiple video streaming sessions sharing multiple access networks. We develop and evaluate an analytical framework for optimal video rate allocation, based on observed available bit rate (ABR) and round trip time (RTT) over each access network, as well as the video distortion-rate (DR) characteristics. The rate allocation is formulated as a convex optimization problem that minimizes the sum of expected distortion of all video *** then present a distributed approximation of the optimization, which enables autonomous rate allocation at each device in a media-and network-aware fashion. Performance of the proposed allocation scheme is compared against robust rate control based on H optimal control and two heuristic schemes employing TCP-style additiveincrease-multiplicative-decrease (AIMD) *** simulate in NS-2 [1] simultaneous streaming of multiple highdefinition (HD) video streams over multiple access networks, using ABR and RTT traces collected on Ethernet, IEEE 802.11g, and IEEE 802.11b networks deployed in a corporate environment. In comparison with heuristic AIMD-based schemes, rate allocation from both the media-aware convex optimization scheme and H optimal control benefit from proactive avoidance of network congestion, and can reduce the average packet loss ratio from 27% to below 2%, while improving the average received video quality by 3.3 - 4.5 dB in PSNR. Copyright 2007 ACM.

关键词： Video streaming

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A practically constant-time MPI Broadcast Algorithm for large-scale InfiniBand Clusters with Multicast

A practically constant-time MPI Broadcast Algorithm for larg...

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International Symposium on Parallel and distributed Processing (IPDPS)

作者： Torsten Hoefler Christian Siebert Wolfgang Rehm Department of Computer Science Chemnitz University of Technology Chemnitz Germany Open Systems Laboratory Indiana University Bloomington IN USA

An efficient implementation of the MPI_BCAST operation is crucial for many parallel scientific applications. The hardware multicast operation seems to be applicable to switch-based infiniband cluster systems. Several approaches have been implemented so far, however there has been no production-ready code available yet. This makes optimal algorithms to a subject of active research. Some problems still need to be solved in order to bridge the semantic gap between the unreliable multicast and MPI_BCAST. The biggest of those problems is to ensure the reliable data transmission in a scalable way. Acknowledgement-based methods that scale logarithmically with the number of participating MPI processes exist, but they do not meet the supernormal demand of high-performance computing. We propose a new algorithm that performs the MPI_BCAST operation in a practically constant time, independent of the communicator size. This method is well suited for large communicators and (especially) small messages due to its good scaling and its ability to prevent parallel process skew. We implemented our algorithm as a collective component for the Open MPI framework using native infiniband multicast and we show its scalability on a cluster with 116 compute nodes, where it saves up to 41% MPI_BCAST latency in comparison to the "TUNED" OpenMPl collective.

关键词： Broadcasting Clustering algorithms Multicast algorithms Large-scale systems Hardware Broadcast technology computer science Open systems Laboratories Chemical technology

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Enhancing Web Services Conversation with Exception Contexts for Handling Exceptions of Composite Services

Enhancing Web Services Conversation with Exception Contexts ...

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IEEE International Conference on e-Commerce technology (CEC)

作者： Hai Liu Qing Li Naijie Gu Dickson K.W. Chiu Department of Computer Science and Technology University of Science and Technology Hefei China Department of Computer Science City University of Hong Kong Hong Kong China Joint Research Laboratory of Excellence City U-USTC Advanced Research Institute Suzhou China Dickson Computer Systems Hong Kong China

The successful execution of a composite service relies on not only its internal design and states, but also the execution of its autonomous, heterogeneous, and distributed participants. Exception handling for a composite service is facing great challenge. This paper presents a mechanism to capture external exception contexts from partners' applications through contexts enhanced Web services conversation (CeWSC), which introduces just a minimal overhead by an effective use of SOAP header and acknowledgement. Moreover, we also propose an enhanced event-driven mechanism to incorporate exception contexts into exception handling for a composite service to facilitate its flexible and reliable execution.

关键词： Web services Context-aware services Simple object access protocol computer science computerized monitoring distributed computing computer languages Java Disaster management technology management

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State Management in Large Scale Group Communication

State Management in Large Scale Group Communication

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IEEE International Conference on Signal Processing and Communications, ICSPC

作者： Dewan Tanvir Ahmed Shervin Shirmohammadi Jauvane C. de Oliveira Distributed and Collaborative Virtual Environments Research Laboratory School of Information Technology and Engineering University of Ottawa Canada Computer Science Department National Laboratory of Scientific Computing ACIMA Laboratory Petropolis Rio de Janeiro Brazil

Current state management practices heavily rely on centralized architectures that pose scalability bottleneck and are expensive to adopt and deploy. In this paper, large scale state management issues are considered and addressed from design perspectives. The intra zonal communication strategies presented in [2][5] assume that peer knows its position in the global coordinate system. In this work, we drop that assumption and approximate peer position through the relative end-to-end delay with respect to landmarks. The technical analysis presented in [4] shows that the protocol has higher diameter in terms of hop distance compared to NICE [6], although it has lower diameter in terms of end-toend delay among the peers. To address that problem we present multiphase mesh construction technique that requires further partitioning of each region into several sub-regions. Both server-side and client-side resources are effectively utilized in collaborative manner while respecting their roles in the system.

关键词： Large-scale systems Delay Scalability Virtual environment Multicast protocols Tree graphs Conference management Environmental management technology management Engineering management

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