Browsing by Subject "architecture"
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Item Anamika: Distributed Service Composition Architecture for Pervasive Computing Environments(ACM, 2002-12-31) Chakraborty, Dipanjan; Joshi, AnupamDevelopment of customized services by discovering, integrating and executing existing ones (refered to as service composition) has received a lot of attention in the last few years with respect to wired, infrastrutcure based web-services. With the advancement in the wireless technology and pervasive computing, we envison that in the near future, we will have such information or services embedded in various wireless devices in our vicinity. However, wired infrastructure-based service discovery and composition architectures do not take into consideration factors arising from the possible mobility of the service providers. In this paper, we present Anamika: a distributed, de-centralized and fault-tolerant design architecture for distributed service discovery and reactive service composition in pervasive environments.Item Asynchronous Transfer Mode (ATM) Technology and ApplicationsRay, JeffreyThe purpose of this paper is to summarize the Asynchronous Transfer Mode (ATM) technology and determine where it is in its evolutionary development. Technologies that fragment data into small pieces typically have very poor performance because there is no mechanism to detect and retransmit lost cells when a piece of the data is lost in transit. The only way to recover the damaged cell is to retransmit the entire large packet again. An alternative to inefficiently retransmitting the entire packet is to only retransmit the individual cells that are lost or damaged. The ATM technology incorporates the ability to retransmit only the cells in each packet that were not received properly. It also enhances transmission performance by reducing flow control activity required at each network link. Surveying recent products serves as an effective barometer for determining how the ATM technology is evolving. State-of-the-market ATM products indicate that an ATM design solution provides unmatched speed, fault-tolerance, and scalability through multiple, meshed inter-switch connections that support load-sharing across networks. At its current point in evolutionary technological development, ATM is a key enabling communications technology that will introduce new applications to users and network providers, as well as provide higher bandwidth capacity to networks. Because of its high-bandwidth capacity and cell-oriented architecture, ATM is the dominant infrastructure for delivering virtually all types of communications, including data, voice, image, and multimedia, into the buildings and desktops of users around the world. By carefully considering critical performance issues, and accommodating existing legacy systems during ATM implementations, the telecommunications industry has insured that ATM will not only be the design solution of the future, but that it can provide cost effective applications today as well.Item A Distributed Service Composition Protocol for Pervasive Environments(IEEE, 2004-03-31) Chakraborty, Dipanjan; Yesha, Yelena; Joshi, AnupamService composition in pervasive environments enables users to utilize services in the environment to solve complex queries. Current work in development of service composition architectures focuses on wired-networked environments where solutions are centralized and tailored towards a reliable network and fixed service topology. In this paper, we present an alternate and novel design architecture of a broker-based distributed service composition protocol for pervasive environments. We present simulation results by comparing our protocol to a centralized architecture for composition. Results show that our distributed broker-based composition architecture perform better than the centralized solution in terms of composition efficiency, broker arbitration efficiency and composition radius.Item An Intelligent Broker Architecture for Context-Aware Systems(University of Maryland, Baltimore County, 2002-12-31) Chen, HarryContext-aware computing is an emerging paradigm to free everyday users from manually configuring and instructing computer systems. As the general trend of computing is progressing towards an open and dynamic infrastructure, building context-aware systems can be difficult and costly. In order to build successful context-aware systems, we must develop an architecture to reduce the difficulty and cost of building these systems. This PhD. dissertation proposal describes a research plan to develop a broker-centric agent architecture that is aimed to relieve the burden of capability-limited agents of acquiring and reasoning about contexts, and to protect the privacy of users in a contextaware environment. The implementation of the Context Broker Archiecture will explore Web Ontology Language for modeling contexts and privacy policies, Jess for building a hybrid reasoning mechanism and JADE/FIPA for realizing broker behaviors and agent communications.Item Private Virtual Infrastructure: A Model for Trustworthy Utility Cloud ComputingKrautheim, F. John; Phatak, Dhananjay S.; Sherman, Alan T.Private Virtual Infrastructure is a security architecture for cloud computing which uses a new trust model to share the responsibility of security in cloud computing between the service provider and client, decreasing the risk exposure to both. Private Virtual Infrastructure is under control of the information owner while the cloud fabric is under control of the service provider. The Private Virtual Infrastructure architecture comprises a cluster of trusted computing fabric platforms that host virtual servers running an application server with a Locator Bot security service. The cloud Locator Bot pre-measures the cloud platform for security properties to determine the trustworthiness of the platform. The Locator Bot uses Trusted Execution Technology and virtual Trusted Platform Modules to pre-measure the target environment and securely provision the Private Virtual Infrastructure in the cloud thus protecting information by preventing data from being placed in malicious or untrusted environments. Private Virtual Infrastructure — including Locator Bot — provides organizations tools to maintain control of their information in the cloud and realize benefits of cloud computing, with assurance that their information is protected. This paper presents a cloud trust model, Private Virtual Infrastructure architecture, and a Locator Bot protocol in enough detail to support further analysis or implementation.Item Semantic Web in a Pervasive Context-Aware Architecture(2003-10-12) Chen, Harry; Finin, Tim; Joshi, AnupamThis document describes a new approach that explores the use of Semantic Web languages in building an architecture for supporting context-aware systems. This new architecture called Context Broker Architecture (CoBrA) differs from other architectures in using the Web Ontology Language OWL for modeling ontologies of context and for supporting context reasoning. Central to our architecture is a broker agent that maintains a shared model of context for all computing entities in the space and enforces the privacy policies defined by the users. We also describe the use of CoBrA and its associated ontologies in prototyping an intelligent meeting room.