Wireless sensor networks have become a very attractive research topic in recent years. Many academic and professional research groups made efforts to construct operative hardware devices and sophisticated software to ...
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ISBN:
(纸本)0769520871
Wireless sensor networks have become a very attractive research topic in recent years. Many academic and professional research groups made efforts to construct operative hardware devices and sophisticated software to meet the special conditions in their projects. But still there has been little done to create a general structure for smart sensors to cooperate and to offer their services to human or software clients. In this paper we present first results of our investigations in this topic. As a test scenario and source of inspiration we set up a sensor network prototype in an office situation, where the physical environment should be measured and adjusted according to specific conditions. In particular the light and humidity state of potted plants within an office should be autonomously adjusted to the plants' special needs as most research associates in our lab forget to care for their plants on a regular basis. On the basis of this prolific scenario we introduce a first stage middleware system architecture providing service distribution and accomplishment within wireless sensor networks. Core components of the architecture have been implemented in hardware and software to show the feasibility and abilities of our approach.
sensor Networks have recently emerged as an important computing platform. However, the energy constrained and limited computing resources of the sensor nodes present major challenges in gathering data. In this work, w...
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ISBN:
(纸本)0769522602
sensor Networks have recently emerged as an important computing platform. However, the energy constrained and limited computing resources of the sensor nodes present major challenges in gathering data. In this work, we propose a new distributed clustering and data aggregation, algorithm, CODA (Cluster-based self-Organizing Data Aggregation), based on the distance from the sink in ad-hoc wireless sensor networks. While cluster-based data gathering is efficient at energy and bandwidth, it's difficult to cluster efficiently. We use the distance vector from the sink, which affects the energy depletion of the network. Our simulation results show that the proposed algorithm balances the energy dissipation over the whole network thus prolongs the network lifetime.
Two important objectives in processing a continuous monitoring queries (CMQ) are: (1) to minimize the processing overheads, especially in communication and query evaluation;and (2) to provide temporally consistent sen...
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Two important objectives in processing a continuous monitoring queries (CMQ) are: (1) to minimize the processing overheads, especially in communication and query evaluation;and (2) to provide temporally consistent sensor data for query evaluation. The first one is important to normal operations of sensor devices while the second one is to ensure the correctness of the query results. We propose periodic pushing schemes, called PerPush and ConPush, to aggregate the sub-query results of a CMQ. To further improve the performance, we propose the Sequential Pushing (SeqPush) scheme for aggregating the sensor data values generated by the sensor nodes which are close to each other, The pushing path in SeqPush follows a sequential pattern according to the semantic of the queries and the results of evaluation of the sub-queries at the nodes participating in the CMQ.
Recent advancements in sensors, wireless technology, and a reduction in the form factor of computing devices, have pushed its closer to the realization of true autonomy in mobile sensing systems. Past field-deployable...
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ISBN:
(纸本)0780382439
Recent advancements in sensors, wireless technology, and a reduction in the form factor of computing devices, have pushed its closer to the realization of true autonomy in mobile sensing systems. Past field-deployable sensing systems for health/biomedical applications and even environmental sensing have been designed for data collection and data transmission at pre-set intervals, rather than for on-board processing. This lack of true autonomy has resulted in systems with lower lifetimes and those that require large amounts of bandwidth to transmit all sensory data at all times. We propose the use of a new, general machine learning architecture that can be used for a variety of autonomous sensing applications that have very limited computing, power, and bandwidth resources. We lay out general solutions for efficient processing in a multi-tiered (three-tier) machine learning framework that is suited for remote, mobile sensing systems with low computing capabilities. Simple pattern recognition methods are used at the sensor level to filter significant events. Novel dimensionality reduction techniques that are designed for classification are used to compress each individual sensor data and pass only relevant information to the mobile multisensor fusion module (second-tier). Statistical classifiers that are capable of handling missing/partial sensory data due to sensor failure or power loss are used to detect critical events and pass the information to the third tier (central server) for manual analysis and/or analysis by advanced pattern recognition techniques. The applicability of our technology in mobile health & alcohol monitoring is shown. Other uses of our solution are also discussed.
The paper describes the use of a wireless sensor network (WSN) for performing parallel pattern recognition computations. A complexity analysis indicates that the proposed algorithm is independent of the number of node...
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ISBN:
(纸本)076952138X
The paper describes the use of a wireless sensor network (WSN) for performing parallel pattern recognition computations. A complexity analysis indicates that the proposed algorithm is independent of the number of nodes and hence may scale up indefinitely with the network. It's shown that any material object once overlaid with a WSN, develops a latent associative memory, which enables the object to memorise some of its critical internal states for a real time comparison with those induced by the transient external conditions.
Clinical diagnosis of pathological conditions is accomplished regularly via the recording and subsequent analysis of a physiological variable from a subject. Problems with current common practice Centre around the obt...
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ISBN:
(纸本)0769520871
Clinical diagnosis of pathological conditions is accomplished regularly via the recording and subsequent analysis of a physiological variable from a subject. Problems with current common practice Centre around the obtrusive and rigid nature of this process. These include the length, timing and location of the diagnostic recording session, transfer of data to clinical staff, liaison between clinical staff and subjects and the integration of such diagnostic check-ups into the overall health care process. We have designed a modular diagnostic monitor that is centered around a wearable computer system which, when integrated into a suitable computer network and database architecture, is capable of addressing the above problems. The system is modular allowing researchers and practitioners to utilise various sensor modules, reconfigure the unit in terms of its on-board storage and wireless telemetry capabilities, select the appropriate level of data preprocessing (before archiving data) and choose the appropriate level and nature of feedback to the subject. The system is GRID enabled, supporting e-clinical-trials. GRID clients can display live data, historical data, or perform data mining.
The proceedings contain 73 papers from Seventh internationalconference of High Performance computing and Grid in Asia Pacific Region, HPCAsia 2004. The topics discussed include: a failure recovery mechanism for distr...
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ISBN:
(纸本)076952138X
The proceedings contain 73 papers from Seventh internationalconference of High Performance computing and Grid in Asia Pacific Region, HPCAsia 2004. The topics discussed include: a failure recovery mechanism for distributed metadata servers in DCFS2;performance evaluation on computational grid environments;a parallel distributed application of the wireless sensor networks;exploring collective communications on a cluster of SMPs;an effective instruction fetch policy for simultaneous multithreaded processors;crossover of the behavior of surface waves in a vibrated granular material;computational approach to hemodynamics in femoral bypass graft;and numerical simulations of the internal flow of rocket engines.
sensor networks are comprised of devices having the ability to communicate, compute and sense the environment. A wide range of information processing tasks have been studied for such networks, including operating syst...
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ISBN:
(纸本)0780384636
sensor networks are comprised of devices having the ability to communicate, compute and sense the environment. A wide range of information processing tasks have been studied for such networks, including operating systems, issues, architecture optimization, and distributed data processing. In this paper, we analyze and compare four different techniques to estimate the gradient of the function represented by the sensor samples. These include: (GA1) a simple device ID defined direction, (GA2) directional derivative, (GA3) polynomial approximation with a plane, and (GA4) polynomial approximation with a quadratic. We compare these based on density of devices per unit area, and noise in the position and sensed data. The interesting result is that GA3 significantly outperforms the other algorithms, although GA1 performs very well and is much easier to compute than the others.
This paper studies a fundamental problem, clock synchronization, in ieee 802.11 ad hoc networks. Clock synchronization is important for frequent hopping spread spectrum (FHSS) to ensure that all stations "hop&quo...
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