213 research outputs found

    An Infrastructure for the Dynamic Distribution of Web Applications and Services

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    This paper presents the design and implementation of an infrastructure that enables any Web application, regardless of its current state, to be stopped and uninstalled from a particular server, transferred to a new server, then installed, loaded, and resumed, with all these events occurring "on the fly" and totally transparent to clients. Such functionalities allow entire applications to fluidly move from server to server, reducing the overhead required to administer the system, and increasing its performance in a number of ways: (1) Dynamic replication of new instances of applications to several servers to raise throughput for scalability purposes, (2) Moving applications to servers to achieve load balancing or other resource management goals, (3) Caching entire applications on servers located closer to clients.National Science Foundation (9986397

    Project Venezia-Gondola (A Framework for P-Commerce)

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    A novel project named Venezia-Gondola (Project V-G) was presented, which describes an application platform that enables the activities of Peer-to-Peer commerce (P-Commerce). A new pattern called the Inverted Model-View-Controller (IMVC) pattern was claimed that is suitable for P-Commerce. The author also explains the principles of the Project V-G and possible architecture for future development

    Towards a new approach for enterprise integration : the semantic modeling approach

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    Manufacturing today has become a matter of the effective and efficient application of information technology and knowledge engineering. Manufacturing firms’ success depends to a great extent on information technology, which emphasizes the integration of the information systems used by a manufacturing enterprise. This integration is also called enterprise application integration (here the term application means information systems or software systems). The methodology for enterprise application integration, in particular enterprise application integration automation, has been studied for at least a decade; however, no satisfactory solution has been found. Enterprise application integration is becoming even more difficult due to the explosive growth of various information systems as a result of ever increasing competition in the software market. This thesis aims to provide a novel solution to enterprise application integration. The semantic data model concept that evolved in database technology is revisited and applied to enterprise application integration. This has led to two novel ideas developed in this thesis. First, an ontology of an enterprise with five levels (following the data abstraction: generalization/specialization) is proposed and represented using unified modeling language. Second, both the ontology for the enterprise functions and the ontology for the enterprise applications are modeled to allow automatic processing of information back and forth between these two domains. The approach with these novel ideas is called the enterprise semantic model approach. The thesis presents a detailed description of the enterprise semantic model approach, including the fundamental rationale behind the enterprise semantic model, the ontology of enterprises with levels, and a systematic way towards the construction of a particular enterprise semantic model for a company. A case study is provided to illustrate how the approach works and to show the high potential of solving the existing problems within enterprise application integration

    Leasing Application Services in E-Commerce Markets

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    A robust multi-server chat application for dynamic distributed networks

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    Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2004."September 3, 2004."Includes bibliographical references (leaf 69).This thesis presents the design and implementation of a robust chat application for dynamic distributed networks. The application uses a decentralized client-server communication model and a reliable communication service to make it robust. The application turned out to be a critical support tool for the MIT Lincoln Laboratory teams participating at the Joint Expeditionary Force Experiment, 2004. The thesis also describes an implementation of several tools for monitoring and analyzing performance of the application.by Michael C. Hamler.M.Eng

    The java.util.concurrent synchronizer framework

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    AbstractMost synchronizers (locks, barriers, etc.) in the J2SE 5.0 java.util.concurrent package are constructed using a small framework based on class AbstractQueuedSynchronizer. This framework provides common mechanics for atomically managing synchronization state, blocking and unblocking threads, and queuing. The paper describes the rationale, design, implementation, usage, and performance of this framework

    An Adaptive Tabu Search Heuristic for the Location Routing Pickup and Delivery Problem with Time Windows with a Theater Distribution Application

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    The time constrained pickup and delivery problem (PDPTW) is a problem of finding a set of routes for a fleet of vehicles in order to satisfy a set of transportation requests. Each request represents a user-specified pickup and delivery location. The PDPTW may be used to model many problems in logistics and public transportation. The location routing problem (LRP) is an extension of the vehicle routing problem where the solution identifies the optimal location of the depots and provides the vehicle schedules and distribution routes. This dissertation seeks to blend the PDPTW and LRP areas of research and formulate a location scheduling pickup and delivery problem with time windows (LPDPTW) in order to model the theater distribution problem and find excellent solutions. This research utilizes advanced tabu search techniques, including reactive tabu search and group theory applications, to develop a heuristic procedure for solving the LPDPTW. Tabu search is a metaheuristic that performs an intelligent search of the solution space. Group theory provides the structural foundation that supports the efficient search of the neighborhoods and movement through the solution space

    Java Grande Forum Report: Making Java Work for High-End Computing

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    This document describes the Java Grande Forum and includes its initial deliverables.Theseare reports that convey a succinct set of recommendations from this forum to SunMicrosystems and other purveyors of Javaâ„¢ technology that will enable GrandeApplications to be developed with the Java programming language

    NMFLUX: Improving Degradation Behavior of Server Applications through Dynamic Nursery Resizing

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    Currently, most generational collectors are tuned to either deliver peak performance when the heap is plentiful, but yield unacceptable performance when the heap is tight or maintain good degradation behavior when the heap is tight, but deliver sub-optimal performance when the heap is plentiful. In this paper, we present NMFLUX (continuously varying the Nursery/Mature ratio), a framework that switches between using a fixed-nursery generational collector and a variable-nursery collector to achieve the best of both worlds; i.e. our framework delivers optimal performance under normal workload, and graceful performance degradation under heavy workload. We use this framework to create two generational garbage collectors and evaluate their performances in both desktop and server settings. The experimental results show that our proposed collectors can significantly improve the throughput degradation behavior of large servers while maintaining similar peak performance to the optimally configured fixed-ratio collector
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