830 resultados para Internet-of-Things, Wireless Sensor Network, CoAP


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A pilot accident and emergency. teleconsulting service was established in Scotland. It was based at the accident and emergency department of the main hospital in Aberdeen. There were three peripheral sites in rural Grampian (Peterhead, Turriff and Huntly) and one in the Shetland Isles. The videoconferencing equipment used was connected by ISDN at 384 kbit/s. During the 15 months of the study, 1998 videoconference calls were made, of which 402 (20%) calls were made to the accident and emergency department for clinical consultations. The majority of the clinical calls (95%) were made between 09:00 and 17:00, and more than 90% were completed within 20 min. During the majority of calls (87%) one or more X-ray images were transmitted. The majority of patients (89%) received treatment without transportation to the main centre in Aberdeen. The present study demonstrated that accident and emergency teleconsultations can be technically reliable, effective in reducing the number of patient transfers and acceptable to the referring clinicians. As a result, approximately pound1.5 million has been made available by the government to develop a national system for Scotland.

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The chemical functionality within porous architectures dictates their performance as heterogeneous catalysts; however, synthetic routes to control the spatial distribution of individual functions within porous solids are limited. Here we report the fabrication of spatially orthogonal bifunctional porous catalysts, through the stepwise template removal and chemical functionalization of an interconnected silica framework. Selective removal of polystyrene nanosphere templates from a lyotropic liquid crystal-templated silica sol–gel matrix, followed by extraction of the liquid crystal template, affords a hierarchical macroporous–mesoporous architecture. Decoupling of the individual template extractions allows independent functionalization of macropore and mesopore networks on the basis of chemical and/or size specificity. Spatial compartmentalization of, and directed molecular transport between, chemical functionalities affords control over the reaction sequence in catalytic cascades; herein illustrated by the Pd/Pt-catalysed oxidation of cinnamyl alcohol to cinnamic acid. We anticipate that our methodology will prompt further design of multifunctional materials comprising spatially compartmentalized functions.

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This article investigates the continuing influence of the past on contemporary politics in Poland and Ukraine by examining the impact of the vocal 'informed' segment of public opinion on mutual relations between the two countries. The section 'What history?' examines the question of exactly what understanding of history matters so much in Polish-Ukrainian relations. The following sections examine how history influences the present, what are the contours of public opinion on Polish-Ukrainian relations within each state, and what is the impact of shared history on the contemporary politics of Polish-Ukrainian relations. Finally, the article suggests a potentially generaliseable hypothesis for future research.

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An investigation is carried out into the design of a small local computer network for eventual implementation on the University of Aston campus. Microprocessors are investigated as a possible choice for use as a node controller for reasons of cost and reliability. Since the network will be local, high speed lines of megabit order are proposed. After an introduction to several well known networks, various aspects of networks are discussed including packet switching, functions of a node and host-node protocol. Chapter three develops the network philosophy with an introduction to microprocessors. Various organisations of microprocessors into multicomputer and multiprocessor systems are discussed, together with methods of achieving reliabls computing. Chapter four presents the simulation model and its implentation as a computer program. The major modelling effort is to study the behaviour of messages queueing for access to the network and the message delay experienced on the network. Use is made of spectral analysis to determine the sampling frequency while Sxponentially Weighted Noving Averages are used for data smoothing.

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Designers of self-adaptive systems often formulate adaptive design decisions, making unrealistic or myopic assumptions about the system's requirements and environment. The decisions taken during this formulation are crucial for satisfying requirements. In environments which are characterized by uncertainty and dynamism, deviation from these assumptions is the norm and may trigger 'surprises'. Our method allows designers to make explicit links between the possible emergence of surprises, risks and design trade-offs. The method can be used to explore the design decisions for self-adaptive systems and choose among decisions that better fulfil (or rather partially fulfil) non-functional requirements and address their trade-offs. The analysis can also provide designers with valuable input for refining the adaptation decisions to balance, for example, resilience (i.e. Satisfiability of non-functional requirements and their trade-offs) and stability (i.e. Minimizing the frequency of adaptation). The objective is to provide designers of self adaptive systems with a basis for multi-dimensional what-if analysis to revise and improve the understanding of the environment and its effect on non-functional requirements and thereafter decision-making. We have applied the method to a wireless sensor network for flood prediction. The application shows that the method gives rise to questions that were not explicitly asked before at design-time and assists designers in the process of risk-aware, what-if and trade-off analysis.

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An optical liquid-level sensor (LLS) based on a long-period fiber grating (LPG) interferometer is proposed and experimentally demonstrated. Two identical 3-dB LPGs are fabricated to form an in-fiber Mach-Zehnder interferometer, and the fiber portion between two LPGs is exposed to the liquid as the sensing element. The sensitivity and measurement range of the sensors employing different orders of cladding modes are investigated both theoretically and experimentally. The experimental results show good linearity and large measurement range. One of the significant advantages of such a sensing structure is that the measurement level is not limited to the length of the LPG itself. Also, the measurement range and sensitivity of the proposed LLS can be readily tailored for a particular applications.