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收集所有交通大學研究人員與學生個人或團體所發表之各項學術著作，涵蓋期刊論文、教師專書、學位論文等項。;;Collections of Publications of NCTU Researchers and Students Like Journal Papers and Thesis.

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🏛️國立陽明交通大學機構典藏

Author: search.filters.author.Chen, Wen-TsuenSubject: search.filters.subject.pervasive computing

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Now showing 1 - 3 of 3
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    A Framework for Simultaneous Message Broadcasting Using CDMA-Based Visible Light Communications
    (2015-12-01)
    Chen, Yan-Ann
    ;
    Chang, Yi-Ting
    ;
    Tseng, Yu-Chee
    ;
    Chen, Wen-Tsuen
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    資訊工程學系
    Internet of Things applications are fast growing recently. One of the things that has a lot of potential is the lighting equipment since it is widely used in our daily life. Recently, the technology of visible light communication (VLC) has been widely discussed. VLC has several advantages, such as freedom of license, line-of-sight security, and less health concern compared with radio-based systems. In addition, the rapid progress of light emitting diode (LED) technology by solid-sate lighting allows VLC to be easily deployed and integrated with the existing lighting infrastructure at low costs. However, VLC, when integrated with lighting infrastructure, is usually for one-way communication and is highly sensitive to external interfering light. Thus, transmitting or broadcasting multiple messages simultaneously over a visible light channel without any preprocessing may result in serious collisions. In this paper, we propose a framework to tackle these problems by optical code division multiple access (CDMA) for VLC. With our approach, a VLC receiver can enter an environment without any prior configuration and can be designed with simple hardware. Even a mobile device with a high-resolution photodiode sensor can be used as a receiver. We demonstrate an application of indoor positioning by querying the location service provider on the Internet with the IDs decoded from the received light signals. The prototyping results reveal some communication properties of CDMA-based VLC and its potential for indoor positioning applications.
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    k-Angle Object Coverage Problem in a Wireless Sensor Network
    (2012-12-01)
    Tseng, Yu-Chee
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    Chen, Po-Yu
    ;
    Chen, Wen-Tsuen
    ;
    資訊工程學系
    ;
    Department of Computer Science
    One of the fundamental issues in sensor networks is the coverage problem, which reflects how well a field is monitored or tracked by sensors. Various versions of this problem have been studied, such as object, area, barrier, and hole coverage problems. In this paper, we define a new k-angle object coverage problem in a wireless sensor network. Each sensor can only cover a limited angle and range, but can freely rotate to any direction to cover a particular angle. Given a set of sensors and a set of objects at known locations, the goal is to use the least number of sensors to k-angle-cover the largest number of objects such that each object is monitored by at least k sensors satisfying some angle constraint. We propose centralized and distributed polynomial-time algorithms to solve this problem. Simulation results show that our algorithms can be effective in maximizing coverage of objects. A prototype system is developed to demonstrate the usefulness of angle coverage.
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    Providing Group Tour Guide by RFIDs and Wireless Sensor Networks
    (2009-06-01)
    Chen, Po-Yu
    ;
    Chen, Wen-Tsuen
    ;
    Tseng, Yu-Chee
    ;
    Huang, Chi-Fu
    ;
    資訊工程學系
    This paper proposes a new application framework for group tour guiding services based on RFIDs and wireless sensor networks. We consider a sensing field mixed with multiple independent tourist groups, each with a leader and several members. Members of a group will follow the moving path of their leader, but may occasionally roam around randomly on their own interests. Sensor nodes have to track leaders' locations and maintain guiding paths from members to leaders. A member may inquire where his/her leader is, and a leader may "recall" his/her members. We propose a feasible solution to such an application by using existing technologies and off-the-shelf components. A group guiding protocol is presented. The design enables reliable group guiding at low-cost and low traffic load. Our prototyping system is reported and system performance is discussed.