4,584 research outputs found

    A component-based middleware framework for configurable and reconfigurable Grid computing

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    Significant progress has been made in the design and development of Grid middleware which, in its present form, is founded on Web services technologies. However, we argue that present-day Grid middleware is severely limited in supporting projected next-generation applications which will involve pervasive and heterogeneous networked infrastructures, and advanced services such as collaborative distributed visualization. In this paper we discuss a new Grid middleware framework that features (i) support for advanced network services based on the novel concept of pluggable overlay networks, (ii) an architectural framework for constructing bespoke Grid middleware platforms in terms of 'middleware domains' such as extensible interaction types and resource discovery. We believe that such features will become increasingly essential with the emergence of next-generation e-Science applications. Copyright (c) 2005 John Wiley & Sons, Ltd

    GRIDKIT: Pluggable overlay networks for Grid computing

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    A `second generation' approach to the provision of Grid middleware is now emerging which is built on service-oriented architecture and web services standards and technologies. However, advanced Grid applications have significant demands that are not addressed by present-day web services platforms. As one prime example, current platforms do not support the rich diversity of communication `interaction types' that are demanded by advanced applications (e.g. publish-subscribe, media streaming, peer-to-peer interaction). In the paper we describe the Gridkit middleware which augments the basic service-oriented architecture to address this particular deficiency. We particularly focus on the communications infrastructure support required to support multiple interaction types in a unified, principled and extensible manner-which we present in terms of the novel concept of pluggable overlay networks

    Chemistry by Mobile Phone (or how to justify more time at the bar)

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    By combining automatic environment monitoring with Java smartphones a system has been produced for the real-time monitoring of experiments whilst away from the lab. Changes in the laboratory environment are encapsulated as simple XML messages, which are published using an MQTT compliant broker. Clients subscribe to the MQTT stream, and produce a user display. An MQTT client written for the Java MIDP platform, can be run on a smartphone with a GPRS Internet connection, freeing us from the constraints of the lab. We present an overview of the technologies used, and how these are helping chemists make the best use of their time

    Semantic Gateway as a Service architecture for IoT Interoperability

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    The Internet of Things (IoT) is set to occupy a substantial component of future Internet. The IoT connects sensors and devices that record physical observations to applications and services of the Internet. As a successor to technologies such as RFID and Wireless Sensor Networks (WSN), the IoT has stumbled into vertical silos of proprietary systems, providing little or no interoperability with similar systems. As the IoT represents future state of the Internet, an intelligent and scalable architecture is required to provide connectivity between these silos, enabling discovery of physical sensors and interpretation of messages between things. This paper proposes a gateway and Semantic Web enabled IoT architecture to provide interoperability between systems using established communication and data standards. The Semantic Gateway as Service (SGS) allows translation between messaging protocols such as XMPP, CoAP and MQTT via a multi-protocol proxy architecture. Utilization of broadly accepted specifications such as W3C's Semantic Sensor Network (SSN) ontology for semantic annotations of sensor data provide semantic interoperability between messages and support semantic reasoning to obtain higher-level actionable knowledge from low-level sensor data.Comment: 16 page

    Federated Identity and Access Management for the Internet of Things

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    Publish/subscribe protocol in wireless sensor networks: improved reliability and timeliness

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    The rapidly-evolving demand of applications using wireless sensor networks in several areas such as building and industrial automation or smart cities, among other, makes it necessary to determine and provide QoS support mechanisms which can satisfy the requirements of applications. In this paper we propose a mechanism that establishes different QoS levels, based on Publish/Subscribe model for wireless networks to meet application requirements, to provide reliable delivery of packet and timeliness. The first level delivers packets in a best effort way. The second one intends to provide reliable packet delivery with a novel approach for Retransmission Timeout (RTO) calculation, which adjusts the RTO depending on the subscriber Packet Delivery Ratio (PDR). The third one provides the same reliable packet delivery as the second one, but in addition, it provides data aggregation trying to be efficient in terms of energy consumption and the use of network bandwidth. The last one provides timeliness in the packet delivery. We evaluate each QoS Level with several performance metrics such as PDR, Message Delivery Ratio, Duplicated and Retransmitted Packet Ratio and Packet Timeliness Ratio to demonstrate that our proposal provides significant improvements based on the increase of the PDR obtained.Peer ReviewedPostprint (author's final draft

    Environmental Observing Systems for Assessing Impacts of Land Use Change

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    The purpose of this research is to evaluate the application of technology solutions for enabling environmental research. This project develops a complete environmental observing system in support of an investigation of the hydrological and ecological impacts of land use change on the coast of South Carolina. The land use change study is an ongoing multi-disciplinary effort involving the collection of a large number of monitored and sampled parameters at Bannockburn Plantation, which is located near the City of Georgetown in South Carolina. Long term monitoring will support a hydrological and ecological assessment of the study site before, during, and after proposed residential and commercial development. There are three primary objectives of this work. The first is the comprehensive instrumentation of a portion of the Bannockburn study site for hydrological parameters. The second is the implementation of a wireless sensor network to support the remote acquisition of monitored data. The third objective is the creation of a reliable and robust software solution for transmitting and distributing real time observation data. Collectively, these three objectives provide a complete environmental observing system. Results of this work will benefit land use change research by providing access to real time observation data and enabling the integration of powerful analysis tools. This research will provide a basis for the development of future environmental observation systems

    Application of Publish/Subscribe Messaging for Management of Streaming Water Resource Data

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    2008 S.C. Water Resources Conference - Addressing Water Challenges Facing the State and Regio

    Reliable and timely event notification for publish/subscribe services over the internet

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    The publish/subscribe paradigm is gaining attention for the development of several applications in wide area networks (WANs) due to its intrinsic time, space, and synchronization decoupling properties that meet the scalability and asynchrony requirements of those applications. However, while the communication in a WAN may be affected by the unpredictable behavior of the network, with messages that can be dropped or delayed, existing publish/subscribe solutions pay just a little attention to addressing these issues. On the contrary, applications such as business intelligence, critical infrastructures, and financial services require delivery guarantees with strict temporal deadlines. In this paper, we propose a framework that enforces both reliability and timeliness for publish/subscribe services over WAN. Specifically, we combine two different approaches: gossiping, to retrieve missing packets in case of incomplete information, and network coding, to reduce the number of retransmissions and, consequently, the latency. We provide an analytical model that describes the information recovery capabilities of our algorithm and a simulation-based study, taking into account a real workload from the Air Traffic Control domain, which evidences how the proposed solution is able to ensure reliable event notification over a WAN within a reasonable bounded time window. © 2013 IEEE

    System Design of Internet-of-Things for Residential Smart Grid

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    Internet-of-Things (IoTs) envisions to integrate, coordinate, communicate, and collaborate real-world objects in order to perform daily tasks in a more intelligent and efficient manner. To comprehend this vision, this paper studies the design of a large scale IoT system for smart grid application, which constitutes a large number of home users and has the requirement of fast response time. In particular, we focus on the messaging protocol of a universal IoT home gateway, where our cloud enabled system consists of a backend server, unified home gateway (UHG) at the end users, and user interface for mobile devices. We discuss the features of such IoT system to support a large scale deployment with a UHG and real-time residential smart grid applications. Based on the requirements, we design an IoT system using the XMPP protocol, and implemented in a testbed for energy management applications. To show the effectiveness of the designed testbed, we present some results using the proposed IoT architecture.Comment: 10 pages, 6 figures, journal pape
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