We focus on an important problem it? the space of ubiquitous computing, namely, programming support for the distributed heterogeneous computing elements that make up this environment. We address the interactive, dynam...
详细信息
ISBN:
(纸本)0769515851
We focus on an important problem it? the space of ubiquitous computing, namely, programming support for the distributed heterogeneous computing elements that make up this environment. We address the interactive, dynamic, and stream-oriented nature of this application class and develop appropriate computational abstractions in the D-Stampede distributed programming system. The key features of D-Stampede include indexing data streams temporally, correlating different data streams temporally, performing automatic distributed garbage collection of unnecessary stream data, supporting high performance by exploiting hardware parallelism where available, supporting platform and language heterogeneity, and dealing with application level dynamism. We discuss the features of D-Stampede, the programming ease it affords, and its performance.
Ubiquitous computing is poised to revolutionize the way we compute and interact with each other. However, unless privacy concerns are taken into account early in the design process, we will end up creating a very effe...
详细信息
ISBN:
(纸本)0769515851
Ubiquitous computing is poised to revolutionize the way we compute and interact with each other. However, unless privacy concerns are taken into account early in the design process, we will end up creating a very effective distributed surveillance system, which would be a dream come trite for electronic stalkers and "big brothers." We present a protocol, which preserves the privacy of users and keeps their communication anonymous. In effect, we create a "mist" that conceals users from the system and other users. Yet, users will still be able to enjoy seamless interaction with services and other entities that wander within the ubiquitous computing environment.
We present a generic module, called Fast Collect. Fast Collect is an implementation of Single-Writer Multi-Reader (SWMR) Shared-Memory in an asynchronous system in which a processor updates its cell and then reads in ...
详细信息
ISBN:
(纸本)0769515851
We present a generic module, called Fast Collect. Fast Collect is an implementation of Single-Writer Multi-Reader (SWMR) Shared-Memory in an asynchronous system in which a processor updates its cell and then reads in any order all the other cells. Our simple implementation of Fast Collect uses some Multi-Writer, Multi-Reader (MWMR) variables and one local boolean per processor, such that eventually, in the absence of contention, i.e. if only a single processor repeatedly per-forms collect, the amortized cost per each collect is a constant. At the example of Disk Paxos we show, how Fast Collect can be used as a building block in wait-free algorithms.
Immediately after power-up, synchronous distributed systems need some time until essential timing properties, which are required to operate correctly, are established. We say that synchronous systems are initially in ...
详细信息
ISBN:
(纸本)0769515851
Immediately after power-up, synchronous distributed systems need some time until essential timing properties, which are required to operate correctly, are established. We say that synchronous systems are initially in asynchronous operation. In this paper we present an algorithm and architectural guidelines that assure the transition from asynchronous to synchronous operation within a bounded duration even in case of failures.
Data replication in distributed databases has been investigated extensively with the hope that it will improve performance, reliability, and availability. However, the growth of the Internet has shown its that current...
详细信息
ISBN:
(纸本)0769515851
Data replication in distributed databases has been investigated extensively with the hope that it will improve performance, reliability, and availability. However, the growth of the Internet has shown its that current replica management do not work well when the replicas are connected by an unreliable network, subject to congestion and dynamic topology changes. In this paper we present a replica update protocol that handles an adaptive partial replication scheme on such a network.
In this paper, the event concept is applied to support the interaction between mobile users anddistributed location-aware systems. Taking a number of examples, the components of an event specification language are de...
详细信息
ISBN:
(纸本)0769515886
In this paper, the event concept is applied to support the interaction between mobile users anddistributed location-aware systems. Taking a number of examples, the components of an event specification language are derived that can be used beyond the domain of location-aware systems.
We define formally the data models WP and AWP especially designed for the dissemination of textual information in distributed event-based systems. We also define the problems of satisfiability, satisfaction, filtering...
详细信息
ISBN:
(纸本)0769515886
We define formally the data models WP and AWP especially designed for the dissemination of textual information in distributed event-based systems. We also define the problems of satisfiability, satisfaction, filtering and entailment, and point out that these problems are fundamental for the deployment of models like the ones presented here in distributed event-based systems.
The Differentiated Services model is the emerging standard to provide Quality-of-Service (QoS) support for the multimedia applications in the future Internet. This model involves bandwidth broker agents to perform the...
详细信息
ISBN:
(纸本)0769515851
The Differentiated Services model is the emerging standard to provide Quality-of-Service (QoS) support for the multimedia applications in the future Internet. This model involves bandwidth broker agents to perform the admission control and network, configuration functionalities. A great deal of efforts has been recently devoted to investigate viable approaches to the implementation of mechanisms that automatically perform the bandwidth broker functions. Yet, 170 standard policy has been so far proposed. In this paper;we propose a distributed measurement based protocol that performs admission control functionalities for multicast traffic in diff-serv networks. The protocol supports dynamic changes of the multicast group membership, it operates on-demand and it supports the Premium Service. We prove that the proposed protocol performs an effective and efficient admission control function.
One of the problems faced by large, global organizations and enterprises is to effectively enable their employees to collaborate across locations. People need collaborative work support while they, are on the move and...
详细信息
ISBN:
(纸本)0769515886
One of the problems faced by large, global organizations and enterprises is to effectively enable their employees to collaborate across locations. People need collaborative work support while they, are on the move and have to share business documents and know-how. Although much work has been done in the area of Computer Supported Collaborative Work (CSCW) to date, supporting mobility is only recently receiving attention. Hence, most of the existing approaches do not deal with emerging mobile teamwork requirements such as locating business documents and expertise through distributed searches, advanced subscription and notification, community building, and mobile information sharing and access. Furthermore, existing applications and approaches are usually difficult to customize to business-specific processes and requirements. The MObile Teamwork Infrastructure for Organizations networking (MOTION)(1) system addresses these requirements and provides a generic teamwork services Application Programming Interface (API), TWSAPI, that can be used to build organization-specific collaborative applications. In this paper, we give an overview of the MOTION TWSAPI and illustrate its usage in building an application that provides document review support.
Peer-to-peer systems have emerged as a popular way to share huge volumes of data. The usability of these systems depends on effective techniques to find and retrieve data;however;current techniques used in existing P2...
详细信息
ISBN:
(纸本)0769515851
Peer-to-peer systems have emerged as a popular way to share huge volumes of data. The usability of these systems depends on effective techniques to find and retrieve data;however;current techniques used in existing P2P systems are often very, inefficient. In this paper we present three techniques for efficient search in P2P systems. We present the design of these techniques, and then evaluate them using a combination of analysis and experiments over Gnutella, the largest open P2P system in operation. We show that while our techniques maintain the same quality of results as currently used techniques, the), use zip to 5 times fewer resources. In addition, we designed our techniques to be simple, so that they can be easily incorporated into existing systems for immediate impact.
暂无评论