2,471 research outputs found

    Design and Performance Analysis of a Non-Standard EPICS Fast Controller

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    The large scientific projects present new technological challenges, such as the distributed control over a communication network. In particular, the middleware EPICS is the most extended communication standard in particle accelerators. The integration of modern control architectures in these EPICS networks is becoming common, as for example for the PXI/PXIe and xTCA hardware alternatives. In this work, a different integration procedure for PXIe real time controllers from National Instruments is proposed, using LabVIEW as the design tool. This methodology is considered and its performance is analyzed by means of a set of laboratory experiments. This control architecture is proposed for achieving the implementation requirements of the fast controllers, which need an important amount of computational power and signal processing capability, with a tight real-time demand. The present work studies the advantages and drawbacks of this methodology and presents its comprehensive evaluation by means of a laboratory test bench, designed for the application of systematic tests. These tests compare the proposed fast controller performance with a similar system implemented using an standard EPICS IOC provided by the CODAC system.Comment: This is the extended version of the Conference Record presented in the IEEE Real-Time Conference 2014, Nara, Japan. This paper has been submitted to the IEEE Transactions on Nuclear Scienc

    Opening the flow of citizen engagement: An exploratory study of social networking services as a potential vehicle for e-participation in the City and County of Honolulu

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    Peer-reviewed journal articleThis study examined the use of Social Networking Services (SNS) by policymakers in the City and County of Honolulu. Interviews identified policymakers’ main reasons for using SNS, examined how SNS was integrated into the policymaking process, and also highlighted issues faced in deploying SNS for government services. The City and County informally initiated use of SNS in 2008, and use remained at an early stage of integration into business processes and operations at the time of this study. Government-operated SNS was primarily used as a one-way-information-based service. In this early stage, SNS was not being used to directly promote e-participation initiatives, although potential future uses were discussed. Government officials noted a spectrum of desired expectations regarding future development of SNS. We recommend an agency-wide use policy be created to provide for consistency of use across administrations and that a formal pilot study, addressing the perspectives of multiple stakeholders, be initiated

    The Sensor Network Workbench: Towards Functional Specification, Verification and Deployment of Constrained Distributed Systems

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    As the commoditization of sensing, actuation and communication hardware increases, so does the potential for dynamically tasked sense and respond networked systems (i.e., Sensor Networks or SNs) to replace existing disjoint and inflexible special-purpose deployments (closed-circuit security video, anti-theft sensors, etc.). While various solutions have emerged to many individual SN-centric challenges (e.g., power management, communication protocols, role assignment), perhaps the largest remaining obstacle to widespread SN deployment is that those who wish to deploy, utilize, and maintain a programmable Sensor Network lack the programming and systems expertise to do so. The contributions of this thesis centers on the design, development and deployment of the SN Workbench (snBench). snBench embodies an accessible, modular programming platform coupled with a flexible and extensible run-time system that, together, support the entire life-cycle of distributed sensory services. As it is impossible to find a one-size-fits-all programming interface, this work advocates the use of tiered layers of abstraction that enable a variety of high-level, domain specific languages to be compiled to a common (thin-waist) tasking language; this common tasking language is statically verified and can be subsequently re-translated, if needed, for execution on a wide variety of hardware platforms. snBench provides: (1) a common sensory tasking language (Instruction Set Architecture) powerful enough to express complex SN services, yet simple enough to be executed by highly constrained resources with soft, real-time constraints, (2) a prototype high-level language (and corresponding compiler) to illustrate the utility of the common tasking language and the tiered programming approach in this domain, (3) an execution environment and a run-time support infrastructure that abstract a collection of heterogeneous resources into a single virtual Sensor Network, tasked via this common tasking language, and (4) novel formal methods (i.e., static analysis techniques) that verify safety properties and infer implicit resource constraints to facilitate resource allocation for new services. This thesis presents these components in detail, as well as two specific case-studies: the use of snBench to integrate physical and wireless network security, and the use of snBench as the foundation for semester-long student projects in a graduate-level Software Engineering course

    Amazon Web Services (AWS) Cloud Platform for Satellite Data Processing

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    As part of NOAA’s Environmental Satellite Processing and Distribution System (ESPDS) program, Solers created a cloud platform for satellite data management and processing. It consists of Enterprise Data Management (EDM) and Enterprise Product Generation (EPG) services, hosted in an Amazon Web Services (AWS) cloud environment, leveraging AWS cloud services and existing NOAA product generation algorithms. While this cloud platform was developed in the context of NOAA/NESDIS satellite data management and processing requirements, it also has tremendous applicability and cost effectiveness for small satellite data management and processing needs. An attractive method for ingesting data from small satellites is the AWS Ground Station. This can help small satellite operators save on costs of real estate, hardware/software, and labor to deploy and operate their own ground stations. The data is ingested via AWS-managed antennas, and made available for further processing in the AWS cloud using COTS RF/ baseband over IP transport services. Once this data has been ingested and made available, the flexible REST APIs from the EDM and EPG services in the AWS cloud make it easy and cost-effective for small satellite operators to catalog and process the data into consumable products, and make them available for access to end users

    Context Aware Computing for The Internet of Things: A Survey

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    As we are moving towards the Internet of Things (IoT), the number of sensors deployed around the world is growing at a rapid pace. Market research has shown a significant growth of sensor deployments over the past decade and has predicted a significant increment of the growth rate in the future. These sensors continuously generate enormous amounts of data. However, in order to add value to raw sensor data we need to understand it. Collection, modelling, reasoning, and distribution of context in relation to sensor data plays critical role in this challenge. Context-aware computing has proven to be successful in understanding sensor data. In this paper, we survey context awareness from an IoT perspective. We present the necessary background by introducing the IoT paradigm and context-aware fundamentals at the beginning. Then we provide an in-depth analysis of context life cycle. We evaluate a subset of projects (50) which represent the majority of research and commercial solutions proposed in the field of context-aware computing conducted over the last decade (2001-2011) based on our own taxonomy. Finally, based on our evaluation, we highlight the lessons to be learnt from the past and some possible directions for future research. The survey addresses a broad range of techniques, methods, models, functionalities, systems, applications, and middleware solutions related to context awareness and IoT. Our goal is not only to analyse, compare and consolidate past research work but also to appreciate their findings and discuss their applicability towards the IoT.Comment: IEEE Communications Surveys & Tutorials Journal, 201

    Digital Multi-Media and the Limits of Privacy Law

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