The Experts below are selected from a list of 48489 Experts worldwide ranked by ideXlab platform

Thomas Funkhouser - One of the best experts on this subject based on the ideXlab platform.

  • ring a Client Server System for multi user virtual environments
    Interactive 3D Graphics and Games, 1995
    Co-Authors: Thomas Funkhouser
    Abstract:

    This paper describes the Client-Server design, implementation and experimental results for a System that supports real-time visual interaction between a large number of users in a shared 3D virtual environment. The key feature of the System is that Server-based visibility algorithms compute potential visual interactions between entities representing users in order to reduce the number of messages required to maintain consistent state among many workstations distributed across a wide-area network. When an entity changes state, update messages are sent only to workstations with entities that can potentially perceive the change—i.e., ones to which the update is visible. Initial experiments show a 40x decrease in the number of messages processed by Client workstations during tests with 1024 entities interacting in a large densely occluded virtual environment.

  • SI3D - RING: a Client-Server System for multi-user virtual environments
    Proceedings of the 1995 symposium on Interactive 3D graphics - SI3D '95, 1995
    Co-Authors: Thomas Funkhouser
    Abstract:

    This paper describes the Client-Server design, implementation and experimental results for a System that supports real-time visual interaction between a large number of users in a shared 3D virtual environment. The key feature of the System is that Server-based visibility algorithms compute potential visual interactions between entities representing users in order to reduce the number of messages required to maintain consistent state among many workstations distributed across a wide-area network. When an entity changes state, update messages are sent only to workstations with entities that can potentially perceive the change—i.e., ones to which the update is visible. Initial experiments show a 40x decrease in the number of messages processed by Client workstations during tests with 1024 entities interacting in a large densely occluded virtual environment.

Yogesh Singh - One of the best experts on this subject based on the ideXlab platform.

  • Empirical analysis of software reliability growth model for three-tier Client-Server System
    International Journal of Industrial and Systems Engineering, 2013
    Co-Authors: Pradeep Kumar, Yogesh Singh
    Abstract:

    In this paper, we present an analytical model for software reliability growth using three-tier Client-Server System composed of user-interface layer, application layer and data layer. We empirically demonstrate how this analytical model can be utilised to predict the reliability of software Systems based on Client-Server architecture. The proposed model has been validated using various parameters in terms of mean square error, mean absolute error, accuracy of estimation, R-values and bias using seven empirical datasets extracted from data and analysis centre for software and other resources. The application of our model can be applied to determine the quality of development process using remaining number of faults in the software during testing phase to avoid any unforeseen situation at later stage. A comparative analysis using three standard classical models has been cited to illustrate experimental results showing significant improvement statistically. Finally, we conclude that proposed approach is more precise in prediction capacity having better capability of generalisation.

  • A SOFTWARE RELIABILITY GROWTH MODEL FOR THREE-TIER Client Server System
    International Journal of Computer Applications, 2010
    Co-Authors: Pradeep Kumar, Yogesh Singh
    Abstract:

    With the ever-increasing role that software is playing in our reallife Systems, concern has steadily grown over the quality of the software products. In today’s life the computers are being used to monitor and control safety critical and civilian Systems with a great demand for high-quality software products. So reliability is a primary concern for both software developers and software users. In literature many software reliability growth models have been proposed over the years to estimate and predict reliability of software products. But it is often very difficult for project managers and practitioners to determine which model is more useful in a particular domain and up to what extent. In this paper we propose a NHPP based software reliability growth model for three-tier Client Server Systems. The present model composed of three layers of Client-Server architecture related to presentation logic, business logic and database stored at backend. Presentation layer contains forms or Server pages which presents the user interface for the application, displays the data, collects the user inputs and sends the requests to next layer. Business layer, which provides the support services to receive the requests for data from user tier, evaluates against business rules, passes them to the data tier and incorporates the business rules for the application. Data layer includes data access logic, database driver(s), query engines used for communicating directly with the data store of a database. The model has been validated through standard dataset consists of software failure data on various projects released from the software reliability dataset and applying to a live commercial application.

Robert Morris - One of the best experts on this subject based on the ideXlab platform.

  • pastwatch a distributed version control System
    Networked Systems Design and Implementation, 2006
    Co-Authors: Alexander Yip, Benjie Chen, Robert Morris
    Abstract:

    Pastwatch is a version control System that acts like a traditional Client-Server System when users are connected to the network; users can see each other's changes immediately after the changes are committed. When a user is not connected, Pastwatch also allows users to read revisions from the repository, commit new revisions and share modifications directly between users, all without access to the central repository. In contrast, most existing version control Systems require connectivity to a centralized Server in order to read or update the repository. Each Pastwatch user's host keeps its own writable replica of the repository, including historical revisions. Users can synchronize their local replicas with each other or with one or more Servers. Synchronization must handle inconsistency between replicas because users may commit concurrent and conflicting changes to their local replicas. Pastwatch represents its repository as a "revtree" data structure which tracks the relationships among these conflicting changes, including any reconciliation. The revtree also ensures that the replicas eventually converge to identical images after sufficient synchronization. We have implemented Pastwatch and evaluate it in a setting distributed over North America. We have been using it actively for more than a year. We show that the System is scalable beyond 190 users per project and that commit and update operations only take 2-4 seconds. Currently, five users and six different projects regularly use the System; they find that the System is easy to use and that the System's replication has masked several network and storage failures.

  • NSDI - Pastwatch: a distributed version control System
    2006
    Co-Authors: Alexander Yip, Benjie Chen, Robert Morris
    Abstract:

    Pastwatch is a version control System that acts like a traditional Client-Server System when users are connected to the network; users can see each other's changes immediately after the changes are committed. When a user is not connected, Pastwatch also allows users to read revisions from the repository, commit new revisions and share modifications directly between users, all without access to the central repository. In contrast, most existing version control Systems require connectivity to a centralized Server in order to read or update the repository. Each Pastwatch user's host keeps its own writable replica of the repository, including historical revisions. Users can synchronize their local replicas with each other or with one or more Servers. Synchronization must handle inconsistency between replicas because users may commit concurrent and conflicting changes to their local replicas. Pastwatch represents its repository as a "revtree" data structure which tracks the relationships among these conflicting changes, including any reconciliation. The revtree also ensures that the replicas eventually converge to identical images after sufficient synchronization. We have implemented Pastwatch and evaluate it in a setting distributed over North America. We have been using it actively for more than a year. We show that the System is scalable beyond 190 users per project and that commit and update operations only take 2-4 seconds. Currently, five users and six different projects regularly use the System; they find that the System is easy to use and that the System's replication has masked several network and storage failures.

Pradeep Kumar - One of the best experts on this subject based on the ideXlab platform.

  • Empirical analysis of software reliability growth model for three-tier Client-Server System
    International Journal of Industrial and Systems Engineering, 2013
    Co-Authors: Pradeep Kumar, Yogesh Singh
    Abstract:

    In this paper, we present an analytical model for software reliability growth using three-tier Client-Server System composed of user-interface layer, application layer and data layer. We empirically demonstrate how this analytical model can be utilised to predict the reliability of software Systems based on Client-Server architecture. The proposed model has been validated using various parameters in terms of mean square error, mean absolute error, accuracy of estimation, R-values and bias using seven empirical datasets extracted from data and analysis centre for software and other resources. The application of our model can be applied to determine the quality of development process using remaining number of faults in the software during testing phase to avoid any unforeseen situation at later stage. A comparative analysis using three standard classical models has been cited to illustrate experimental results showing significant improvement statistically. Finally, we conclude that proposed approach is more precise in prediction capacity having better capability of generalisation.

  • A SOFTWARE RELIABILITY GROWTH MODEL FOR THREE-TIER Client Server System
    International Journal of Computer Applications, 2010
    Co-Authors: Pradeep Kumar, Yogesh Singh
    Abstract:

    With the ever-increasing role that software is playing in our reallife Systems, concern has steadily grown over the quality of the software products. In today’s life the computers are being used to monitor and control safety critical and civilian Systems with a great demand for high-quality software products. So reliability is a primary concern for both software developers and software users. In literature many software reliability growth models have been proposed over the years to estimate and predict reliability of software products. But it is often very difficult for project managers and practitioners to determine which model is more useful in a particular domain and up to what extent. In this paper we propose a NHPP based software reliability growth model for three-tier Client Server Systems. The present model composed of three layers of Client-Server architecture related to presentation logic, business logic and database stored at backend. Presentation layer contains forms or Server pages which presents the user interface for the application, displays the data, collects the user inputs and sends the requests to next layer. Business layer, which provides the support services to receive the requests for data from user tier, evaluates against business rules, passes them to the data tier and incorporates the business rules for the application. Data layer includes data access logic, database driver(s), query engines used for communicating directly with the data store of a database. The model has been validated through standard dataset consists of software failure data on various projects released from the software reliability dataset and applying to a live commercial application.

Alexander Yip - One of the best experts on this subject based on the ideXlab platform.

  • pastwatch a distributed version control System
    Networked Systems Design and Implementation, 2006
    Co-Authors: Alexander Yip, Benjie Chen, Robert Morris
    Abstract:

    Pastwatch is a version control System that acts like a traditional Client-Server System when users are connected to the network; users can see each other's changes immediately after the changes are committed. When a user is not connected, Pastwatch also allows users to read revisions from the repository, commit new revisions and share modifications directly between users, all without access to the central repository. In contrast, most existing version control Systems require connectivity to a centralized Server in order to read or update the repository. Each Pastwatch user's host keeps its own writable replica of the repository, including historical revisions. Users can synchronize their local replicas with each other or with one or more Servers. Synchronization must handle inconsistency between replicas because users may commit concurrent and conflicting changes to their local replicas. Pastwatch represents its repository as a "revtree" data structure which tracks the relationships among these conflicting changes, including any reconciliation. The revtree also ensures that the replicas eventually converge to identical images after sufficient synchronization. We have implemented Pastwatch and evaluate it in a setting distributed over North America. We have been using it actively for more than a year. We show that the System is scalable beyond 190 users per project and that commit and update operations only take 2-4 seconds. Currently, five users and six different projects regularly use the System; they find that the System is easy to use and that the System's replication has masked several network and storage failures.

  • NSDI - Pastwatch: a distributed version control System
    2006
    Co-Authors: Alexander Yip, Benjie Chen, Robert Morris
    Abstract:

    Pastwatch is a version control System that acts like a traditional Client-Server System when users are connected to the network; users can see each other's changes immediately after the changes are committed. When a user is not connected, Pastwatch also allows users to read revisions from the repository, commit new revisions and share modifications directly between users, all without access to the central repository. In contrast, most existing version control Systems require connectivity to a centralized Server in order to read or update the repository. Each Pastwatch user's host keeps its own writable replica of the repository, including historical revisions. Users can synchronize their local replicas with each other or with one or more Servers. Synchronization must handle inconsistency between replicas because users may commit concurrent and conflicting changes to their local replicas. Pastwatch represents its repository as a "revtree" data structure which tracks the relationships among these conflicting changes, including any reconciliation. The revtree also ensures that the replicas eventually converge to identical images after sufficient synchronization. We have implemented Pastwatch and evaluate it in a setting distributed over North America. We have been using it actively for more than a year. We show that the System is scalable beyond 190 users per project and that commit and update operations only take 2-4 seconds. Currently, five users and six different projects regularly use the System; they find that the System is easy to use and that the System's replication has masked several network and storage failures.