In this paper we study two important problems - coverage-boundary detection and implementing distributed hash tables in ad-hoc wireless networks. these problems frequently arise in service location and relocation in w...
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ISBN:
(纸本)0769521525
In this paper we study two important problems - coverage-boundary detection and implementing distributed hash tables in ad-hoc wireless networks. these problems frequently arise in service location and relocation in wireless networks. For the centralized coverage-boundary problem we prove a Omega(n log n) lower bound for n devices. We show that both problems can be effectively reduced to the problem of computing Voronoi overlays, and maintaining these overlays dynamically. Since the computation of Voronoi diagrams requires O(n log n) time, our solution is optimal for the computation of the coverage-boundary. We present efficient distributed algorithms for computing and dynamically maintaining Voronoi overlays, and prove the stability properties for the latter - i.e., if the nodes stop moving, the overlay stabilizes to the correct Voronoi overlay. Finally, we present experimental results in the context of the two selected applications, which validate the performance of our distributed and dynamic algorithms.
Recently, several schemes have been proposed for IP traffic source identification for tracing denial of service (DoS) attacks. Most of these schemes require very large number of packets to conduct the traceback proces...
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ISBN:
(纸本)0769521525
Recently, several schemes have been proposed for IP traffic source identification for tracing denial of service (DoS) attacks. Most of these schemes require very large number of packets to conduct the traceback process, which results in lengthy and complicated procedure. In this paper we address this issue by proposing a new scheme, called Probabilistic Pipelined Packet Marking (PPPM), which employs the concept of "pipeline" for propagating marking information from one marking router to another so that it eventually reaches the destination. the key benefit of this pipeline process lies in drastically reducing the number of packets that is required for the traceback process. We evaluate the effectiveness of the proposed scheme for various performance metrics through combination of analytical and simulation studies. Our studies show that the proposed scheme offers high attack source detection percentage, and attack source localization distance of less than two hops under different attack scenarios.
distributed file systems have been extensively studied in the past, but they are still far from wide acceptance over heterogeneous network environments. Most traditional network file systems target the tight-couple hi...
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ISBN:
(纸本)0769521525
distributed file systems have been extensively studied in the past, but they are still far from wide acceptance over heterogeneous network environments. Most traditional network file systems target the tight-couple highspeed networks only, and do not work well in the wide-area setting. Several communication optimization techniques are proposed in the context of wide-area file systems, but these approaches do not take into consideration the file characteristics and may instead introduce extra computing overhead when the network condition is good. We envision that the capability of providing adaptive, seamless file access to personal documents across diverse network connections plays an important role in the success of future distributed file systems. In this paper we propose to build an adaptive distributed file system which provides the "ClosE and Go, Open and Resume" (Cegor) semantics across heterogeneous network connections, ranging from high-bandwidth local area network to low-bandwidth dial-up connection. Our approach relies on a set of new techniques for managing adaptive access to remote files, including three components: system support for secure, transparent reconnection at different places, semantic-view based caching to reduce communication frequencies in the system, and type-specific communication optimization to minimize the bandwidth requirement of synchronizations between clients and servers.
Multicast is very useful way for large-scale distributing multimedia over the network. It can significantly reduce the bandwidth required to transmit same multimedia over the network to multiple receivers. this proper...
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the proceedings contain 144 papers. the special focus in this conference is on Support Tools, Performance Evaluation, Scheduling, Load Balancing and Compilers for High Performance. the topics include: An approach base...
ISBN:
(纸本)3540229248
the proceedings contain 144 papers. the special focus in this conference is on Support Tools, Performance Evaluation, Scheduling, Load Balancing and Compilers for High Performance. the topics include: An approach based on components, web services and workflow tools;some techniques for automated, resource-aware distributed and mobile computing in a multi-paradigm programming system;support tools and environments;efficient pattern search in large traces through successive refinement;adaptive control system with hardware performance counters;a tool for source-to-source transformations and real-life compiler tests;a time-coherent model for the steering of parallel simulations;dynamic performance tuning environment;imprecise exceptions in distributed parallel components;a data structure oriented monitoring environment for Fortran openMP programs;an approach for symbolic mapping of memory references;evaluating openMP performance analysis tools withthe apart test suite;understanding the behavior and performance of non-blocking communications in MPI;generation of simple analytical models for message passing applications;parallel peps tool performance analysis using stochastic automata networks;scheduling under conditions of uncertainty;scheduling tasks sharing files from distributed repositories;lookahead scheduling for reconfigurable grid systems;more legal transformations for locality;a polyhedral approach to ease the composition of program transformations;using data compression to increase energy savings in multi-bank memories;architecture-independent meta-optimization by aggressive tail splitting;parallel and distributed databases, data mining and knowledge discovery and a large-scale digital library system to integrate heterogeneous data of distributed databases.
the new principals of organization of parallel input-output of the optical information in the personal computer from the fiber-optical measuring lines are considered. the device has block structure and has two mode of...
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ISBN:
(纸本)0819453226
the new principals of organization of parallel input-output of the optical information in the personal computer from the fiber-optical measuring lines are considered. the device has block structure and has two mode of operation: calibration mode of operation and work mode of operation. In the calibration mode of operation computing, system is adaptation to condition of the Solution problem of reconstruction information about parameters of monitoring physical fields. In the work mode of operation the device implements the adaptive processing of incoming optical radiation.
Permutation is a frequently-used communication pattern in parallel and distributedcomputing systems and telecommunication networks. Node-disjoint routing has important applications in guided wave optical interconnect...
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ISBN:
(纸本)0769521525
Permutation is a frequently-used communication pattern in parallel and distributedcomputing systems and telecommunication networks. Node-disjoint routing has important applications in guided wave optical interconnects where the optical "crosstalk" between messages passing the same switch should be avoided. In this paper, we consider routing arbitrary permutations on an optical baseline network (or reverse baseline network) with node-disjoint paths. We first prove the equivalence between the set of admissible permutations (or semi-permutations) of a baseline network and that of its reverse network based on a step-by-step permutation routing. We then show that an arbitrary permutation can be realized in a baseline network (or a reverse baseline network) with node-disjoint paths in four passes, which beats the existing results [6], [7] that a permutation can be realized in an n x n banyan network with node-disjoint paths in O(n(1/2)) passes. this represents the currently best-known result for the number of passes required for routing an arbitrary permutation with node-disjoint paths in unique-path multi-stage networks. Unlike other unique path NHNs (such as omega networks or banyan networks), only baseline networks have been found to possess such four-pass routing property. We present routing algorithms in both self-routing style and central-controlled style. Different from the recent work in [22], which also gave a four-pass node-disjoint routing algorithm for permutations, the new algorithm is efficient in transmission time for messages of any length, while the algorithm in [22] can work efficiently only for long messages. Comparisons with previous results demonstrate that routing in a baseline network proposed in this paper could be a better choice for routing permutations due to its lowest hardware cost and near-optimal transmission time.
the proceedings contain 41 papers. the special focus in this conference is on Algebraic Methodology and Software Technology. the topics include: Algebraic approaches to problem generalisation;a science of software des...
ISBN:
(纸本)3540223819
the proceedings contain 41 papers. the special focus in this conference is on Algebraic Methodology and Software Technology. the topics include: Algebraic approaches to problem generalisation;a science of software design;glass box and black box views of state-based system specifications;abstraction for safety, induction for liveness;counting votes with formal methods;producing run-time checks from integrity constraints;behavioural types and component adaptation;towards correspondence carrying specifications;formalizing and proving semantic relations between specifications by reflection;model-checking systems with unbounded variables without abstraction;a generic software safety document generator;linear temporal logic and Z refinement;formal JVM code analysis in JavaFAN;state space reduction for process algebra specifications;a hybrid logic of knowledge supporting topological reasoning;a language for configuring multi-level specifications;flexible proof reuse for software verification;deductive verification of distributed groupware systems;formal verification of a commercial smart card applet with multiple tools;abstracting call-stacks for interprocedural verification of imperative programs;refining mobile UML state machines;verifying invariants of component-based systems through refinement;modelling concurrent interactions;proof support for raise by a reuse approach based on institutions and separate compositional analysis of class-based object-oriented languages.
the interesting properties of P2P systems (high availability despite peer volatility, support for heterogeneous architectures, high scalability, etc.) make them attractive for distributedcomputing. However, conductin...
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