215 research outputs found

    A syndication-based messaging protocol for the global RFID network

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    Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2008.Includes bibliographical references (p. 89).This Master of Engineering thesis describes the design and implementation of a syndication based messaging protocol for the global RFID network. The motivation behind the design is to develop a scalable model that can be applied to "Internet of Things" technologies, which are used to encompass the large data volume of physical objects in the world. In striving to achieve this, the underlying publish/subscribe system implementation can be applied to large-scale communication and information networks. The messaging protocol presented is text-based; this approach offers a human-understandable, user-friendly protocol. Similar to RSS version 2.0, the format of the message conforms to existing XML specifications, but also adopts a structure that represents the RFID data organization more clearly. As an example method, Windows Forms applications were created to provide a Graphical User Interface (GUI) component for visualizing the publish/subscribe messaging model. The design implements a lightweight messaging protocol that is both scalable to model large-scale networks and extensible to allow aggregation of content across multiple data sources.by Miao Sun.M.Eng

    Supporting Cyber-Physical Systems with Wireless Sensor Networks: An Outlook of Software and Services

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    Sensing, communication, computation and control technologies are the essential building blocks of a cyber-physical system (CPS). Wireless sensor networks (WSNs) are a way to support CPS as they provide fine-grained spatial-temporal sensing, communication and computation at a low premium of cost and power. In this article, we explore the fundamental concepts guiding the design and implementation of WSNs. We report the latest developments in WSN software and services for meeting existing requirements and newer demands; particularly in the areas of: operating system, simulator and emulator, programming abstraction, virtualization, IP-based communication and security, time and location, and network monitoring and management. We also reflect on the ongoing efforts in providing dependable assurances for WSN-driven CPS. Finally, we report on its applicability with a case-study on smart buildings

    A series of case studies to enhance the social utility of RSS

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    RSS (really simple syndication, rich site summary or RDF site summary) is a dialect of XML that provides a method of syndicating on-line content, where postings consist of frequently updated news items, blog entries and multimedia. RSS feeds, produced by organisations or individuals, are often aggregated, and delivered to users for consumption via readers. The semi-structured format of RSS also allows the delivery/exchange of machine-readable content between different platforms and systems. Articles on web pages frequently include icons that represent social media services which facilitate social data. Amongst these, RSS feeds deliver data which is typically presented in the journalistic style of headline, story and snapshot(s). Consequently, applications and academic research have employed RSS on this basis. Therefore, within the context of social media, the question arises: can the social function, i.e. utility, of RSS be enhanced by producing from it data which is actionable and effective? This thesis is based upon the hypothesis that the fluctuations in the keyword frequencies present in RSS can be mined to produce actionable and effective data, to enhance the technology's social utility. To this end, we present a series of laboratory-based case studies which demonstrate two novel and logically consistent RSS-mining paradigms. Our first paradigm allows users to define mining rules to mine data from feeds. The second paradigm employs a semi-automated classification of feeds and correlates this with sentiment. We visualise the outputs produced by the case studies for these paradigms, where they can benefit users in real-world scenarios, varying from statistics and trend analysis to mining financial and sporting data. The contributions of this thesis to web engineering and text mining are the demonstration of the proof of concept of our paradigms, through the integration of an array of open-source, third-party products into a coherent and innovative, alpha-version prototype software implemented in a Java JSP/servlet-based web application architecture

    On the cloud deployment of a session abstraction for service/data aggregation

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    Dissertação para obtenção do Grau de Mestre em Engenharia InformáticaThe global cyber-infrastructure comprehends a growing number of resources, spanning over several abstraction layers. These resources, which can include wireless sensor devices or mobile networks, share common requirements such as richer inter-connection capabilities and increasing data consumption demands. Additionally, the service model is now widely spread, supporting the development and execution of distributed applications. In this context, new challenges are emerging around the “big data” topic. These challenges include service access optimizations, such as data-access context sharing, more efficient data filtering/ aggregation mechanisms, and adaptable service access models that can respond to context changes. The service access characteristics can be aggregated to capture specific interaction models. Moreover, ubiquitous service access is a growing requirement, particularly regarding mobile clients such as tablets and smartphones. The Session concept aggregates the service access characteristics, creating specific interaction models, which can then be re-used in similar contexts. Existing Session abstraction implementations also allow dynamic reconfigurations of these interaction models, so that the model can adapt to context changes, based on service, client or underlying communication medium variables. Cloud computing on the other hand, provides ubiquitous access, along with large data persistence and processing services. This thesis proposes a Session abstraction implementation, deployed on a Cloud platform, in the form of a middleware. This middleware captures rich/dynamic interaction models between users with similar interests, and provides a generic mechanism for interacting with datasources based on multiple protocols. Such an abstraction contextualizes service/users interactions, can be reused by other users in similar contexts. This Session implementation also permits data persistence by saving all data in transit in a Cloud-based repository, The aforementioned middleware delivers richer datasource-access interaction models, dynamic reconfigurations, and allows the integration of heterogenous datasources. The solution also provides ubiquitous access, allowing client connections from standard Web browsers or Android based mobile devices

    Cost-Aware Resource Management for Decentralized Internet Services

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    Decentralized network services, such as naming systems, content distribution networks, and publish-subscribe systems, play an increasingly critical role and are required to provide high performance, low latency service, achieve high availability in the presence of network and node failures, and handle a large volume of users. Judicious utilization of expensive system resources, such as memory space, network bandwidth, and number of machines, is fundamental to achieving the above properties. Yet, current network services typically rely on less-informed, heuristic-based techniques to manage scarce resources, and often fall short of expectations. This thesis presents a principled approach for building high performance, robust, and scalable network services. The key contribution of this thesis is to show that resolving the fundamental cost-benefit tradeoff between resource consumption and performance through mathematical optimization is practical in large-scale distributed systems, and enables decentralized network services to meet efficiently system-wide performance goals. This thesis presents a practical approach for resource management in three stages: analytically model the cost-benefit tradeoff as a constrained optimization problem, determine a near-optimal resource allocation strategy on the fly, and enforce the derived strategy through light-weight, decentralized mechanisms. It builds on self-organizing structured overlays, which provide failure resilience and scalability, and complements them with stronger performance guarantees and robustness under sudden changes in workload. This work enables applications to meet system-wide performance targets, such as low average response times, high cache hit rates, and small update dissemination times with low resource consumption. Alternatively, applications can make the maximum use of available resources, such as storage and bandwidth, and derive large gains in performance. I have implemented an extensible framework called Honeycomb to perform cost-aware resource management on structured overlays based on the above approach and built three critical network services using it. These services consist of a new name system for the Internet called CoDoNS that distributes data associated with domain names, an open-access content distribution network called CobWeb that caches web content for faster access by users, and an online information monitoring system called Corona that notifies users about changes to web pages. Simulations and performance measurements from a planetary-scale deployment show that these services provide unprecedented performance improvement over the current state of the art

    A series of case studies to enhance the social utility of RSS

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    RSS (really simple syndication, rich site summary or RDF site summary) is a dialect of XML that provides a method of syndicating on-line content, where postings consist of frequently updated news items, blog entries and multimedia. RSS feeds, produced by organisations or individuals, are often aggregated, and delivered to users for consumption via readers. The semi-structured format of RSS also allows the delivery/exchange of machine-readable content between different platforms and systems. Articles on web pages frequently include icons that represent social media services which facilitate social data. Amongst these, RSS feeds deliver data which is typically presented in the journalistic style of headline, story and snapshot(s). Consequently, applications and academic research have employed RSS on this basis. Therefore, within the context of social media, the question arises: can the social function, i.e. utility, of RSS be enhanced by producing from it data which is actionable and effective? This thesis is based upon the hypothesis that the fluctuations in the keyword frequencies present in RSS can be mined to produce actionable and effective data, to enhance the technology's social utility. To this end, we present a series of laboratory-based case studies which demonstrate two novel and logically consistent RSS-mining paradigms. Our first paradigm allows users to define mining rules to mine data from feeds. The second paradigm employs a semi-automated classification of feeds and correlates this with sentiment. We visualise the outputs produced by the case studies for these paradigms, where they can benefit users in real-world scenarios, varying from statistics and trend analysis to mining financial and sporting data. The contributions of this thesis to web engineering and text mining are the demonstration of the proof of concept of our paradigms, through the integration of an array of open-source, third-party products into a coherent and innovative, alpha-version prototype software implemented in a Java JSP/servlet-based web application architecture

    Ur/Web: A Simple Model for Programming the Web

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    The World Wide Web has evolved gradually from a document delivery platform to an architecture for distributed programming. This largely unplanned evolution is apparent in the set of interconnected languages and protocols that any Web application must manage. This paper presents Ur/Web, a domain-specific, statically typed functional programming language with a much simpler model for programming modern Web applications. Ur/Web's model is unified, where programs in a single programming language are compiled to other "Web standards" languages as needed; modular, supporting novel kinds of encapsulation of Web-specific state; and exposes simple concurrency, where programmers can reason about distributed, multithreaded applications via a mix of transactions and cooperative preemption. We give a tutorial introduction to the main features of Ur/Web, formalize the basic programming model with operational semantics, and discuss the language implementation and the production Web applications that use it.National Science Foundation (U.S.) (Grant CCF-1217501
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