Browsing by Author "Kao, Yu-Fen"

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From wireless sensor networks towards cyber physical systems
(2011-08-01)
Wu, Fang-Jing
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Kao, Yu-Fen
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Tseng, Yu-Chee
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資訊工程學系
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Department of Computer Science
In the past two decades, a lot of research activities have been dedicated to the fields of mobile ad hoc network (MANET) and wireless sensor networks (WSN). More recently, the cyber physical system (CPS) has emerged as a promising direction to enrich the interactions between physical and virtual worlds. In this article, we first review some research activities in WSN, including networking issues and coverage and deployment issues. Then, we review some CPS platforms and systems that have been developed recently, including health care, navigation, rescue, intelligent transportation, social networking, and gaming applications. Through these reviews, we hope to demonstrate how CPS applications exploit the physical information collected by WSNs to bridge real and cyber spaces and identify important research challenges related to CPS designs. (C) 2011 Elsevier B.V. All rights reserved.
Price-based resource allocation for wireless ad hoc networks with multi-rate capability and energy constraints
(2008-09-25)
Kao, Yu-Fen
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Huang, Jen-Hung
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管理科學系
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Department of Management Science
Wireless ad hoc networks have attracted a lot of attentions recently. Resource allocation in such networks needs to address both fairness and overall network performance. Pricing is a prospective direction to regulate behaviors of individual nodes while providing incentives for cooperation. In this work, we develop some pricing strategies for resource allocation by taking account of factors like multiple transmission rates and energy consumption of nodes, which have not been well studied in former works. Multi-rate transmission capability is commonly seen in most wireless products nowadays, while energy is one of the most important resources in portable devices. We propose a clique-based model which allows us to achieve optimal resource utilization and fairness among network flows when multi-rate transmission is considered. We also show how to extend the model to dynamically adjust prices based on energy consumptions of flows. In particular, our model takes into account energy consumptions in the transmitters' side, the receivers' side, and those that are non-transmitters and non-receivers but are interfered by these activities. So our model can more accurately reflect the real energy constraint in a wireless network. Simulation results are presented to show the convergence and other properties of these strategies. (C) 2008 Elsevier B.V. All rights reserved.