Efficient aggregation of data collected by sensors is crucial for a successful application of wireless sensor networks (WSNs). Both minimizing the energy cost and reducing the time duration (or called latency) of data...
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ISBN:
(纸本)9781424451142
Efficient aggregation of data collected by sensors is crucial for a successful application of wireless sensor networks (WSNs). Both minimizing the energy cost and reducing the time duration (or called latency) of data aggregation have been extensively studied for WSNs. Algorithms withtheoretical performance guarantees are only known under the protocol interference model, or graph-based interference models generally. In this paper, we study the problem of designing time efficient aggregation algorithm under the physical interference model. To the best of our knowledge, no algorithms withtheoretical performance guarantees are known for this problem in the literature. We propose an efficient algorithm that produces a data aggregation tree and a collision-free aggregation schedule. We theoretically prove that the latency of our aggregation schedule is bounded by O(R+Delta) time-slots. Here R is the network radius and Delta is the maximum node degree in the communication graph of the original network. In addition, we derive the lower-bound of latency for any aggregation scheduling algorithm under the physical interference model. We show that the latency achieved by our algorithm asymptotically matches the lower-bound for random wireless networks. Our extensive simulation results corroborate our theoretical analysis.
the development of ambient assisted living (AAL) systems, which are tailored to health or elder care, requires specific methods and tools. AAL systems make often use of wireless sensor networks, machine learning algor...
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ISBN:
(纸本)9781424437702
the development of ambient assisted living (AAL) systems, which are tailored to health or elder care, requires specific methods and tools. AAL systems make often use of wireless sensor networks, machine learning algorithms and sensory devices. Since wireless sensor networks and their sensors are inhomogeneous, it became apparent that such systems need to cope with different hardware platforms, different programming languages, unreliable wireless communication, energy constraints, data analysis algorithms, recognition of situations, and deployment options. Developers to date tend to use a bottom-up approach: hardware components dictate the development of AAL systems and thereby restrict the range of use cases that can be realized;domain experts by contrast would prefer a top-down approach and model the system's functionality independently from the hardware platform. Currently available software development environments and tools do not adequately support domain experts and developers to accomplish these tasks efficiently. this paper presents methods that support domain experts in their top-down approach, as well as technically experienced developers in their bottom-up approach. the implemented tools enable a model-driven software development process (from plalform-independent modeling to generating AAL application code) and thus facilitate programming AAL systems.
Wireless sensor networks (WSNs) play a crucial role in visual surveillance for automatic object detection, such as real-time traffic monitoring, vehicle parking control, intrusion detection, and so on. these online su...
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ISBN:
(纸本)9781605586182
Wireless sensor networks (WSNs) play a crucial role in visual surveillance for automatic object detection, such as real-time traffic monitoring, vehicle parking control, intrusion detection, and so on. these online surveillance applications require efficient computation and distribution of complex image data over the wireless camera network with high reliability and detection rate in real time Traditionally, such applications make use of camera modules capturing a flow of two dimensional images through time. the resulting huge amount of image data impose severe requirements on the resource constrained WSN nodes which need to store, process and deliver the image data or results within a certain deadline In this paper we present a WSN framework based on line sensor architecture capable of capturing a continuous stream of temporal one dimensional image (line image) the associated one dimensional image processing algorithms are able to achieve significantly faster processing results with much less storage and bandwidth requirement while conserving the node energy. Moreover, the different operating modes offered by the proposed WSN framework provide the end user with different tradeoff in terms of node computation versus communication bandwidth efficiency Our framework is Illustrated through a testbed using ieee 802 154 communication stack and a real-time operating system along with one dimensional image processing the proposed line sensor based WSN architecture can also be a desirable solution to broader multimedia based WSN systems.
In this paper, requirements and technologies for realizing sensor overlay networks are introduced. sensor overlay networks should provide distributed data fusion mechanism, i.e. in-network computing feature, for effec...
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In this paper, requirements and technologies for realizing sensor overlay networks are introduced. sensor overlay networks should provide distributed data fusion mechanism, i.e. in-network computing feature, for effective computing on distributedsensors. sensor overlay networks should also have scalability, maintainability and sustainability. To treat such requirements, we have developed an open source framework called 'PIAX'. the overview of PIAX and its technologies to treat sensor overlay networks are described in this paper.
In recent years, Zigbee becomes one of the most promising protocols for ubiquitous networking. So, it would be essential that residential gateways can effectively interoperate with Zigbee-enabled ubiquitous devices su...
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ISBN:
(纸本)9783642028298
In recent years, Zigbee becomes one of the most promising protocols for ubiquitous networking. So, it would be essential that residential gateways can effectively interoperate with Zigbee-enabled ubiquitous devices such as wireless sensors and digital appliances to provide ubiquitous home services. In this paper, I design and implement an effective architecture for dynamic integration of Zigbee devices into OSGi-based residential gateways, where ad hoc Zigbee devices are represented as device proxy services. And such proxy services can be automatically downloaded, installed and registered to the OSGi service registry by the dynamic device integration manager on the corresponding devices' joining the Zigbee network. thus, ubiquitous home service applications can discover proxy services for the required Zigbee devices, and access the devices withthe common proxy service interfaces without concerning the specific device access protocols and libraries.
Location-based Services are gaining more and more users and are available on a broad set of mobile devices. Due to their complexity such services are currently only provided by large organizations that use their own p...
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Defect prediction is an important task in the mining of software repositories, but the quality of predictions varies strongly within and across software projects. In this paper we investigate the reasons why the predi...
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ISBN:
(纸本)9781424434930
Defect prediction is an important task in the mining of software repositories, but the quality of predictions varies strongly within and across software projects. In this paper we investigate the reasons why the prediction quality is so fluctuating due to the altering nature of the bug (or defect) fixing process. therefore, we adopt the notion of a concept drift, which denotes that the defect prediction model has become unsuitable as set of influencing features has changed - usually due to a change in the underlying bug generation process (i.e., the concept). We explore four open source projects (Eclipse, OpenOffice, Netbeans and Mozilla) and construct file-level and project-level features for each of them from their respective CVS and Bugzilla repositories. We then use this data to build defect prediction models and visualize the prediction quality along the time axis. these visualizations allow us to identify concept drifts and - as a consequence - phases of stability and instability expressed in the level of defect prediction quality. Further, we identify those project features, which are influencing the defect prediction quality using both a tree induction-algorithm and a linear regression model. Our experiments uncover that software systems are subject to considerable concept drifts in their evolution history. Specifically, we observe that the change in number of authors editing a file and the number of defects fixed by them contribute to a project's concept drift and therefore influence the defect prediction quality. Our findings suggest that project managers using defect prediction models for decision making should be aware of the actual phase of stability or instability due to a potential concept drift.
Taiwan is located at the collision boundary of the Philippine sea plate and the Eurasian plate. the mountain terrain is precipitous and the region, on the whole, is characterized by fragile rocks and frequent seismic ...
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ISBN:
(纸本)9781424445622
Taiwan is located at the collision boundary of the Philippine sea plate and the Eurasian plate. the mountain terrain is precipitous and the region, on the whole, is characterized by fragile rocks and frequent seismic activity. In addition, the concentrated torrential rainfall brought by typhoons cause extensive disasters, debris flow, the most serious disaster caused by torrential rainfall, lead to very heavy casualties in recent years. there are 17 fixed debris flow monitoring stations and 2 mobile stations deployed in Taiwan. However, the whole architecture was designed in late 2000 and implemented by traditional and proprietary methodologies. Hence, several interoperability issues have been unveiled in the recent years when the needs of interoperability increased. In this study, we propose a whole new and open standards based debris flow monitoring architecture following the Service Oriented Architecture (SOA) paradigm. Relevant Open Geospatial Consortium (OGC) standards (for example Web Processing Service, WPS specification and sensor Web Enablement, SWE technologies) and advancements from Grid computing where lead into the proposed architecture. the use of open standards and distributedcomputing technologies in the proposed architecture enables heterogeneous resources (data, processing and computing power) interoperability. this study also implements an OGC WPS Grid Processing Profile that was developed in the OGC Web Services, Phase 6 (OWS-6) initiative of the OGC Interoperability Program.
this paper proposes mu T-Kernel, a real-time operating system for networked tiny devices, which adopts a preemptive priority-based scheduling. It provides a sophisticated application programming interface to facilitat...
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ISBN:
(纸本)9781424437702
this paper proposes mu T-Kernel, a real-time operating system for networked tiny devices, which adopts a preemptive priority-based scheduling. It provides a sophisticated application programming interface to facilitate software development. In addition, to provide rich functionalities with a small-footprint, the kernel is reconfigurable with respect to the API. Moreover, mu T-ernel supports a power management which utilizes the periodicity of WSN applications. We conducted performance analyses of the memory footprint and energy consumption, and migrated sample applications to show the programmability of mu T-Kernel. Our results show mu T-Kernel is effective for developing WSN systems while realizing a kernel small enough to fit into a resource-constrained node.
We study query scheduling in Wireless sensor Networks (WSNs) with a focus on two important metrics: Quality of Service (QoS) and Quality of Data (QoD). the motivation comes from our observation that most WSN schedulin...
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