This paper addresses the need of semantic component in the grid environment to discover and describe the grid resources semantically. We propose semantic grid architecture by introducing a knowledge layer at the top o...
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This paper addresses the need of semantic component in the grid environment to discover and describe the grid resources semantically. We propose semantic grid architecture by introducing a knowledge layer at the top of Gridbus broker architecture and thereby enabling broker to discover resources semantically. The semantic component in the knowledge layer enables semantic description of grid resources with the help of ontology template. The ontology template has been created using Protege-OWL editor for different types of computing resources in the grid environment. The Globus Toolkit's MDS is used to gather grid resource information and Protege-OWL libraries are used to dynamically create knowledge base of grid resources. Algernon inference engine is used for interacting with the knowledge base to discover suitable resources.
The paper recasts the problem of feature location in source code as a decision-making problem in the presence of uncertainty. The main contribution consists in the combination of two existing techniques for feature lo...
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The paper recasts the problem of feature location in source code as a decision-making problem in the presence of uncertainty. The main contribution consists in the combination of two existing techniques for feature location in source code. Both techniques provide a set of ranked facts from the software, as result to the feature identification problem. One of the techniques is based on a scenario based probabilistic ranking of events observed while executing a program under given scenarios. The other technique is defined as an information retrieval task, based on the latent semantic indexing of the source code. We show the viability and effectiveness of the combined technique with two case studies. A first case study is a replication of feature identification in Mozilla, which allows us to directly compare the results with previously published data. The other case study is a bug location problem in Mozilla. The results show that the combined technique improves feature identification significantly with respect to each technique used independently
The increasing heterogeneity, dynamism and uncertainty of emerging DCE (Distributed Computing Environment) systems imply that an application must be able to detect and adapt to changes in its state, its requirements a...
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The increasing heterogeneity, dynamism and uncertainty of emerging DCE (Distributed Computing Environment) systems imply that an application must be able to detect and adapt to changes in its state, its requirements and the state of the system to meet its desired QoS constraints. As system and application scales increase, ad hoc heuristic-based approaches to application adaptation and self-management quickly become insufficient. This paper builds on the Accord programming system for rule-based self-management and extends it with model-based control and optimization strategies. This paper also presents the development of a self-managing data streaming service based on online control using Accord. This service is part of a Grid-based fusion simulation workflow consisting of long-running simulations, executing on remote supercomputing sites and generating several terabytes of data, which must then be streamed over a wide-area network for live analysis and visualization. The self-managing data streaming service minimize data streaming overheads on the simulations, adapt to dynamic network bandwidth and prevent data loss. An evaluation of the service demonstrating its feasibility is presented.
Although increasing evidence suggests that superior performance requires alignment between firms' strategies and production processes, it is not known if such alignment is relevant for software development process...
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Although increasing evidence suggests that superior performance requires alignment between firms' strategies and production processes, it is not known if such alignment is relevant for software development processes. This study breaks new ground by examining how firms align their software processes, products, and strategies in Internet application development. Drawing upon the literatures in strategy, operations management, and information systems, we identify four dimensions that influence alignment: the business unit strategy, the level of product customization, the level of process customization, and the volume of customers. To examine how these dimensions are synchronized, we conducted detailed case studies of Internet application development in nine varied firms including both start-ups and established "brick and mortar" companies. Our analyses reveal that the firms in our study do use differing processes for Internet application development, and that many of the firms match their software process choices to product characteristics, customer volume, and business unit strategies. We develop concept maps for the firms that are in alignment to illustrate how managers configure specific product and process dimensions. We also offer potential explanations for why some firms are misaligned, such as attempting to execute incompatible strategies, the lack of coordination between marketing and production strategies, the too rapid expansion of process scope, and inflexible barriers to rapid adaptation of process. Our study contributes detailed insights into how software processes are customized to complement different types of product requirements and strategies.
An algorithm for time division multiple access (TDMA) is found to be applicable in converting existing distributed algorithms into a model that is consistent with sensor networks. Such a TDMA service needs to be self-...
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With the advent of Grid and application technologies, scientists and engineers are building more and more complex applications to manage and process large data sets, and execute scientific experiments on distributed r...
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Distributed denial of service (DDoS) attacks on the Internet have become an immediate problem. As DDoS streams do not have common characteristics, currently available intrusion detection systems (IDS) can not detect t...
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ISBN:
(纸本)9728865252
Distributed denial of service (DDoS) attacks on the Internet have become an immediate problem. As DDoS streams do not have common characteristics, currently available intrusion detection systems (IDS) can not detect them accurately. As a result, defend DDoS attacks based on current available IDS will dramatically affect legitimate traffic. In this paper, we propose a distributed approach to defend against distributed denial of service attacks by coordinating across the Internet. Unlike traditional IDS, we detect and stop DDoS attacks within the intermediate network. In the proposed approach, DDoS defense systems are deployed in the network to detect DDoS attacks independently. A gossip based communication mechanism is used to exchange information about network attacks between these independent detection nodes to aggregate information about the overall network attacks observed. Using the aggregated information, the individual defense nodes have approximate information about global network attacks and can stop them more effectively and accurately. To provide reliable, rapid and widespread dissemination of attack information, the system is built as a peer to peer overlay network on top of the internet.
This paper identifies challenges in managing resources in a Grid computing environment and proposes computational economy as a metaphor for effective management of resources and application scheduling. It identifies d...
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This paper describes TRAP/C++, a software tool that enables new adaptable behavior to be added to existing C++ programs in a transparent fashion. In previous investigations, we used an aspectoriented approach to manua...
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ISBN:
(纸本)1595930396
This paper describes TRAP/C++, a software tool that enables new adaptable behavior to be added to existing C++ programs in a transparent fashion. In previous investigations, we used an aspectoriented approach to manually define aspects for adaptation infrastructure, which were woven into the original application code at compile time. In follow-on work, we developed TRAP, a transparent shaping technique for automatically generating adaptation aspects, where TRAP/J is a specific instantiation of TRAP. This paper presents our work into building TRAP/C++, which was intended to be a port of TRAP/J into C++. Designing TRAP/C++ required us to overcome two major hurdles: lack of reflection in C++ and the incompatibility between the management of objects in C++ and the aspect weaving technique used in TRAP/J. We used generative programming methods to produce two tools, TrapGen and TrapCC, that work together to produce the desired TRAP/C++ functionality. Details of the TRAP/C++ architecture and operation are presented, which we illustrate with a description of a case study that adds dynamic auditing capabilities to an existing distributed C++ application. Copyright 2005 ACM.
Embedded systems are pervasive and frequently used for critical systems with time-dependent functionality. Dwyer et al. have developed qualitative specification patterns to facilitate the specification of critical pro...
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ISBN:
(纸本)9781581139631
Embedded systems are pervasive and frequently used for critical systems with time-dependent functionality. Dwyer et al. have developed qualitative specification patterns to facilitate the specification of critical properties, such as those that must be satisfied by embedded systems. Thus far, no analogous repository has been compiled for real-time specification patterns. This paper makes two main contributions: First, based on an analysis of timing-based requirements of several industrial embedded system applications, we created real-time specification patterns in terms of three commonly used real-time temporal logics. Second, as a means to further facilitate the understanding of the meaning of a specification, we offer a structured English grammar that includes support for real-time properties. We illustrate the use of the real-time specification patterns in the context of property specifications of a real-world automotive embedded system. Copyright 2005 ACM.
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