• Journal of the Korea Society of Computer and Information
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• v.18 no.1
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• pp.137-147
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• 2013

The RFID(Radio Frequency Identification) and the WSN(Wireless Sensor Network) have technical similarities and mutual effects, they have been recognized to be studied separately, and sufficient studies have not been conducted on the technical integration of the RFID and the WSN. Therefore, EPC global which realized the issue proposed the EPC(Electronic Produce Code) Sensor Network to efficiently integrate and interoperate the RFID and WSN technologies based on the international standard EPC global network. The proposed EPC Sensor Network technology uses the Complex Event Processing method in the middleware to integrate data occurring through the RFID and the WSN in a single environment and to interoperate the events based on the EPC global network. However, as the EPC Sensor Network technology continuously performs its operation even in the case that the minimum conditions are not to be met to find complex events in the middleware, its operation cost rises. Therefore, to address the problems of the existing system, we defined the minimum conditions of the complex events to detect unnecessary complex events in the middleware, and proposed an algorithm that can extract complex events only when the minimum conditions are to be met. To examine the minimum conditions, a index and a query index are used to extract complex events. To evaluate the performance of the proposed methods, In the case of the method of extracting complex events based on a bitmap index, we used the existing extraction method and NS2 simulation to evaluate its performance and thus to show its good performance in terms of the number of operation and the processing time for the complex events.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.2B
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• pp.80-90
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• 2006

WSN(Wireless Sensor Network) performs to detect and collect environmental information for one purpose. As examples, WSN is applicable for home network, patient management of a hospital, logistics management, status detection during the war and so on. The WSN is composed of a sink node and several sensor nodes and has a constraint in an aspect of energy consumption caused by limited battery resource. So many required mechanisms in WSN should consider the remained energy condition. A routing mechanism is requested to deliver the collected information to a sink considering energy efficiency in WSN. There have been many researches to establish (a) route(s) for data delivery to the sink. In this paper, we propose establishment of efficient routes. We proposed a uniform routing mechanism together with considering energy efficiency. For the routing, we define energy probability as routing metrics information and Performs suppression of exchange of control messages. In addition, we derive to uniformly consume the energy of the sensor node when establishing the routes. Also, we evaluate and analyze the energy efficiency for proposed mechanisms through NS-2 simulator.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.3
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• pp.116-124
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• 2011

In this study, a new method to estimate the bridge deflection is developed by using Wireless Tilt Sensor. Most of evaluations of structural integrity, it is very important to measure the geometric profile, which is a major factor representing the global behavior of civil structure, especially bridges. In the past, Because of the lack of appropriate methods to measure the deflection curve of bridges on site, the measurement of deflection had been done restrictly within just a few discrete points along the bridge. Also the measurement point could be limited to locations installed with displacement transducers. So, in this study, the deflection of the structure was measured by wireless tilt sensor instead of LVDT(Linear Variable Differential Transformer). Angle change of tilt sensor shows structural behavior by the change of the resistor values which is presented to voltage. Moreover, the maximum deflection was calculated by changing the deflection angle which was calculated as V(measured voltage) ${\times}$F(factor) to deflection. The experimental tests were carried out to verify the developed deflection estimation techniques. Because the base of tilt measuring is the gravity, uniform measurement is possible independent of a measuring point. Also, measuring values were showed very high accuracy.

• Journal of Digital Contents Society
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• v.9 no.4
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• pp.601-606
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• 2008

U-Healthcare is one of the major applications in ubiquitous sensor network. U-Healthcare has potential to become a critical service for the people who immediately require emergency ambulatory attention. This paper describes about the real time pulse monitoring and reporting system, consisting of two components: thus, the one is a reliable bio-sensor that continuously monitors the pulse information of the subject, and the other is the automatic transfer system that transmits pulse information to both his/her family and hospital care system through the Base Station. In the hospital, this bio-information can be used to treat the patient accordingly. I designed the pulse information monitored by a bio-sensor module that transfers the pulse information to both the Base Station and the central monitoring system through transmitting protocols such as Zigbee and TCP/IP, as well as designed the architecture of information packets for the corresponding protocols. Furthermore, the central monitoring system automatically parses the pulse information of the subject into the web database server, which can continuously provides the real time information and status of the subject via an internet browser to the clients who are family members of the subject and the authenticated medical care personnel as well.

• Proceedings of the Korea Information Processing Society Conference
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• 2011.11a
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• pp.543-545
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• 2011

최근 유비쿼터스에 대한 관심이 높아지고 있고 이에 대한 응용기술인 USN(Ubiquitous Sensor Network) 기술을 사용하여 사용자가 편리한 삶을 살기 위한 기술이 늘어나고 있다. 본 논문에서는 이 중에 하나인 센서를 기반으로 한 블라인드 시스템에 대해서 기술한다. 이 스마트 블라인드는 빛의 양을 조도센서를 이용해 측정하여 자동적으로 동작하도록 제어하는 시스템을 적용한 스마트 블라인드에 대해서 기술했다. 사용자가 편리하도록 블라인드를 제어할 수 있는 시스템을 개발하고 실제 적용하는데 그 목적이 있고 이를 위해서 조도센서를 이용하여 빛 감지 후 빛의 양을 파악하고 그 데이터 값으로 모터를 동작시켜서 블라인드를 제어한다.

• Journal of the Korean Society for Railway
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• v.11 no.4
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• pp.364-370
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• 2008

In this paper, we proposed new sensor network architecture with autonomous robots based on beacon mode and implemented real time monitoring system in real test-bed environment. The proposed scheme offers beacon based real-time scheduling for reliable association process with parent nodes and dynamically assigns network address by using NAA (Next Address Assignment) mechanism. For the large scale multi-sensor processing, our real-time monitoring system accomplished the intelligent database processing, which can generate not only the alert messages to the civilians but also process various sensing data such as fire, air, temperature and etc. Moreover, we also developed mobile robot which can support network mobility. Though the performance evaluation by using real test-bed system, we illustrate that our proposed system demonstrates promising performance for emergence monitoring systems.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.807-810
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• 2011

The sensor network technology for core technology of ubiquitous computing is in the spotlight recently, the research on sensor network is proceeding actively which is composed many different sensor node. USN(Ubiquitous Sensor Network) is the network that widely applies for life of human being. It works out to sense, storage, process, deliver every kind of appliances and environmental information from the stucktags and sensors. And it is possible to utilize to measure and monitor about the place of environmental pollution which is difficult for human to install. It's studied constantly since it be able to compose easily more subminiature, low-power, low-cost than previous one. And also it spotlights an important field of study, graft the green IT and IT of which the environment and IT unite stragically onto the Network. The problem for the air pollution in the office or the indoor except a specific working area is the continuously issue since the human beings have lived in the dwelling facilities. Measures for that problem are urgently needed. It's possible to solve for the freshair of outside with enough ventilation but that is the awkward situation to be managed by person. This study is the system engineering to management for indoor air condition under the sensor network. And research for efficiently manage an option.

• Proceedings of the Korean Society of Computer Information Conference
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• 2013.07a
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• pp.345-347
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• 2013

최근 환경문제의 심각성이 고조됨에 따라 Co2 배출량 감소계획에 따른 세계 각국의 정부주도로 민간 및 지방자치단체에서도 그린에너지, 저탄소 녹색성장 프로젝트, 승용차요일제 등 다양한 정책을 시행하고 있다. 따라서 탄소저감의 효율적인 방안으로서 승용차 운행을 줄이고 자전거 활용의 활성화에 대한 관심이 증대되고 있다. 본 논문에서는 자전거활용의 활성화를 위하여 자전거 도난방지와 관리를 위한 저비용의 무선 네트워크를 활용한 임베디드 제어 모듈과 모바일 서비스 기반의 자전거 관리시스템을 설계하고 구현 기법을 제안하였다.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.2 s.58
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• pp.28-37
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• 2006

전파 자원은 국가의 무형 자산으로서 자원이 한정되어 있는 반면에 이에 대한 수요가 급증하면서 전파 자원의 가치가 점점 높아지고 있다. 특히 국내의 경우 IT839 전략으로 추진 중인 WiBro(Wireless Broadband), DMB(Digital Multimedia Broadcasting), Home Network, Telematics(Telecommunication Informatics), WCDMA(Wide Code Division Multiple Access), RFID/USN(Radio Frequency Identification/Ubiquitous Sensor Network) 등 무선 주파수를 이용하는 새로운 서비스가 증가하면서 주파수 자원에 대한 중요성은 더욱 강조되고 있다. 종래의 전파 정책이 정부가 정책을 세우고 이를 관리하는 Command-and-Control 위주였다면, 향후의 전파 정책은 OpYN1020en Spectrum 정책으로 전환될 것으로 전망된다. 본 고에서는 전파 자원의 효율적인 이용을 도모하는 일반적인 CR(Cognitive Radio) 기술에 대하여 언급하고, 이를 이동성이 없는 고정 환경에 적용하기 위한 IEEE 802.22 WRAN 시스템의 물리계층 전송 규격 사양, 프레임구조 및 현재 논의되고 있는 기술에 대하여 논의한다.

• Journal of Digital Convergence
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• v.14 no.8
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• pp.269-276
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• 2016

Public Safty-LTE(Long Term Evolution) is being deployed in the direction of reducing cost by using both of municipal network and commercial network. However, LTE Network is difficult to ensure the survivability during the information communication infrastructure failures. In addition, it is vulnerable in communication coverage of inside buildings and underground. In this study, we propose to implement effectively the network survivability technique through the convergence to the proven technology. As the advent of the IoT Age, smart sensors which are embedded in the environment and the things will be able to provide a useful infrastructure for ensuring the network survivability. Based on the feature of the smart sensor, we designed the sink node architecture to guarantee the network survivability in disaster situation through the convergence of the small cell technology and extension of wireless network coverage technology. The computing power inherent in the environment is a valuable resource that can be utilized in the disaster situation.