distributed stream processing systems (DSPSs) have many important applications such as sensor data analysis, network security, and business intelligence. Failure management is essential for DSPSs that often require hi...
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ISBN:
(纸本)9781424431748
distributed stream processing systems (DSPSs) have many important applications such as sensor data analysis, network security, and business intelligence. Failure management is essential for DSPSs that often require highly-available system operations. In this paper, we explore a new predictive failure management approach that employs online failure prediction to achieve more efficient failure management than previous reactive or proactive failure management approaches. We employ light-weight stream-based classification methods to perform online failure forecast. Based on the prediction results, the system can take differentiated failure preventions on abnormal components only. Our failure prediction model is tunable, which can achieve a desired tradeoff between failure penalty reduction and prevention cost based on a user-defined reward function. To achieve low-overhead online learning, we propose adaptive data stream sampling schemes to adaptively adjust measurement sampling rates based on the states of monitored components, and maintain a limited size of historical training data using reservoir sampling. We have implemented an initial prototype of the predictive failure management framework within the IBM System S distributed stream processing system. Experiment results show that our system can achieve more efficient failure management than conventional reactive and proactive approaches, while imposing low overhead to the DSPS.
As a consequence of the growing importance of distributed Generation (DG) it's very important to study the distribution network behavior. In this paper, voltage profile and gradient are analyzed taking in account ...
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ISBN:
(纸本)9781424417438
As a consequence of the growing importance of distributed Generation (DG) it's very important to study the distribution network behavior. In this paper, voltage profile and gradient are analyzed taking in account power in-feed/out-feed of DG. the influence of reactive power requirements on the network voltage levels, based in the comparison of software simulation results with real-life behavior, are also studied. this paper equally analyzes the impact of DG on the substation transformers taps changers, with and without DG. Finally, it's analyzed the impact of DG on protection systems functioning in a 60 kV network.
Cross-layer design for wireless networks aims at optimizing system-wide performance measures by exploiting dependencies between different network layers. In this paper, an opportunistic power assignment algorithms for...
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ISBN:
(纸本)9781424424887
Cross-layer design for wireless networks aims at optimizing system-wide performance measures by exploiting dependencies between different network layers. In this paper, an opportunistic power assignment algorithms for IR-UWB sensor networks is presented that is especially designed for distributed signal detection under resource constraints. Specifically, the objective is to minimize the global probability of error of distributed detection systems, given a fixed level of total transmission power. the cross-layer approach for the allocation of transmission power is based on individual sensor detection quality as well as location information. It leads to significant performance gains compared to uniform power assignment for boththe parallel and the serial sensor network topology.
Topology control is an effective method to improve the energy efficiency of wireless sensor networks (WSNs). Traditional approaches are based on the assumption that a pair of nodes is either "connected" or &...
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ISBN:
(纸本)9781424431748
Topology control is an effective method to improve the energy efficiency of wireless sensor networks (WSNs). Traditional approaches are based on the assumption that a pair of nodes is either "connected" or "disconnected". these approaches are called connectivity-based topology control. In real environments however, there are many intermittently connected wireless links called lossy links. Taking a succeeded lossy link as an advantage, we are able to construct more energy-efficient topologies. Towards this end, we propose a novel opportunity-based topology control. We show that opportunity-based topology control is a problem of NP-hard. To address this problem in a practical way, we design a fully distributed algorithm called CONREAP based on reliability theory. We prove that CONREAP has a guaranteed performance. the worst running time is O(|E|) where E is the link set of the original topology, and the space requirement for individual nodes is O(d) where d is the node degree. To evaluate the performance of CONREAP we design and implement a prototype system consisting of 50 Berkeley Mica2 motes. We also conducted comprehensive simulations. Experimental results show that compared withthe connectivity-based topology control algorithms, CONREAP can improve the energy efficiency of a network up to 6 times.
Recently, researches on underwater sensor networks (USN) for ocean development and disaster prevention have been emerged as one or interesting topics. Since low-power, high-speed and inexpensive communication modem is...
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ISBN:
(纸本)9780769534923
Recently, researches on underwater sensor networks (USN) for ocean development and disaster prevention have been emerged as one or interesting topics. Since low-power, high-speed and inexpensive communication modem is a prerequisite For deployment of USN, we design and implement an underwater modem by utilizing general-purpose waterproof ultrasonic sensors in this paper. Also, we make an experiment in a water tank containing sensor nodes and a sink node, it gateway, and show that point-to-multipoint communication is possible at a data rate of 1 kbps.
Bomb disposal suits contain a large amount of padding and armour to protect the wearer's vital organs in the case of explosion. the combination of the heavy (roughly 40kg) suit, physical exertion, and the environm...
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ISBN:
(纸本)9789898111326
Bomb disposal suits contain a large amount of padding and armour to protect the wearer's vital organs in the case of explosion. the combination of the heavy (roughly 40kg) suit, physical exertion, and the environment in which these suits are worn can cause the wearer's temperature to rise to uncomfortable and potentially dangerous levels during missions. this paper reports on the development of a wearable wireless sensing system suitable for deployment in such manned bomb disposal missions. In its final form, the system will be capable of making in-network autonomous decisions related to the actuation of cooling within the suit, in order to increase the comfort of the wearer. In addition, it will allow an external observer to remotely monitor the health and comfort of the operative. Laboratory experiments withthe instrumented suit show how skin temperature varies differently for different skin sites, motivating the need for multiple, distributed sensing. the need for timely application of in-suit cooling is also shown, as well as the importance of monitoring the overall health of the wearer of the suit.
Acoustic sensor networks can provide rich multimedia information, which doubtlessly benefit a plethora of data hungry applications such as environment monitoring, health care, emergency response, and security surveill...
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ISBN:
(纸本)9780769534923
Acoustic sensor networks can provide rich multimedia information, which doubtlessly benefit a plethora of data hungry applications such as environment monitoring, health care, emergency response, and security surveillance. In this paper, we study the data unit delivery process of cluster head by developing a discrete-time Markov chain model and a M/G/1 queue model, based on a single-hop cluster-based sensor networks architecture. Our analysis shows how arrival rate and the number of sensor nodes influence mean waiting lime and how many sensor nodes that a cluster head can support. the result of our study can be used to guide the design of real-time acoustic wireless sensor networks system.
In hierarchical sensor networks, pairwise key path construction would make no sense for cluster heads as the security of those higher level nods depends on that of the normal ones along withthe key path. Vector-based...
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In Wireless sensor Networks(WSNs), secure data aggregation is an important application. Previous works are implemented by authentication among neighboring sensors. Considering that in many cases, data aggregation is b...
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ISBN:
(纸本)9780769533483
In Wireless sensor Networks(WSNs), secure data aggregation is an important application. Previous works are implemented by authentication among neighboring sensors. Considering that in many cases, data aggregation is both spatial and temporal correlation, this paper proposes a distributed and Localized Secure Data Aggregation Algorithm Based on Behavior Trust(BTDA). the security and reliability of the algorithm are implemented by using statistical hypothesis test for matching the reading sequence of sensors and statistical characteristics of the data aggregation. Simulation shows the algorithm efficiently.
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