• Journal of Institute of Control, Robotics and Systems
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• v.14 no.3
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• pp.318-325
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• 2008

In this paper, a dynamic backoff adjustment method of IEEE 802.15.4 is proposed for time-critical sporadic data in a noisy factory environment. For this, a superframe of IEEE 802.15.4 is applied to a real-time mixed data (periodic data, sporadic data, and non real-time message) transmission in factory communication systems. To guarantee a channel access of real-time sporadic(non-periodic) data, a transmission method using the dynamic backoff is applied to wireless control networks. For the real-time property, different initial BE, CW parameters are used for the dynamic backoff adjustment method. The simulat-ion results show an enhancement of the real-time performance of sporadic emergency data. The proposed method provides the channel access of real-time sporadic data efficiently, and guarantee real-time transmission simultaneously within a limite-d timeframe.

• Journal of information and communication convergence engineering
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• v.9 no.1
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• pp.69-73
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• 2011

Twitter is a microblogging service that allows its user to share short messages called tweets with each other. All the tweets are visible on a public timeline. These tweets have the valuable geospatial component and particularly time critical events. In this paper, our interest is in the rapid detection of disaster events such as tsunami, tornadoes, forest fires, and earthquakes. We describe the detection system of disaster events and show the way to detect a target event from Twitter data. This research examines the three disasters during the same time period and compares Twitter activity and Internet news on Google. A significant result from this research is that emergency detection could begin using microblogging service.

• Proceedings of the Korean Society of Computer Information Conference
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• 2014.01a
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• pp.473-476
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• 2014

최근 여성, 아동을 대상으로 한 범죄 발생률이 증가 하고 있다. 이러한 통계를 기반으로 우리 생활 깊숙이 자리 매김한 스마트 폰 애플리케이션을 활용하여 범죄를 예방에 도움을 줄 수 있는 애플리케이션을 개발 하였다. SQLite를 이용한 Database기능과 Google API Package의 MapView를 사용하여 지인의 정보를 놓고 언제든지 사용자의 위치정보를 빠르게 전달할 수 있는 앱을 구현 하여 주기적인 위치전송으로 인한 사용자의 위치파악이 가능하고, 위급상황 시 긴급전화를 이용하여 사고 대처가 가능하며, GPS를 이용한 본인의 위치 주변 지리 파악이 용이하다. 또한 수신자가 발신자의 이동경로를 한눈에 봄으로써 위치파악에 용이 함으로 안전한 귀가 서비스를 제공한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.3 no.1
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• pp.75-82
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• 1999

This paper describes the implementation of wireless realtime monitoring system using modified CSMA/CA protocol. This system consists of wireless modem, central monitor, mobile station, DB server, and offer advantage of mobility, reduced installation time, long-term cost savings, and so on. And this system offers patient position pursuit service. Patient position pursuit service must be offered to deal with emergency which can be occured during patient movement. This paper proposes modified CSMA/CA protocol and patient position pursuit algorithm, implements wireless realtime monitoring system using it.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.13-18
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• 2008

The 2005 west off Fukuoka earthquake with Mjma 7.0 occurred in the vicinity of Fukuoka city with 1.4 million populations, which had been regarded as rather seismically inactive in Japan. The strong motion records by K-net indicated PGV of 64 cm/s in Fukuoka city and some condominium buildings sustained extensive non-structural damages. In this study, we conducted a questionnaire survey for residents of 8 condominium buildings located in the downtown area of Fukuoka city after the earthquake. The results indicate that damaged nonstructural walls and distorted doors disrupted evacuation route for many occupants, and furniture and content damage on upper floors became severer resulting in higher rates of human casualty. Earthquake preparedness for indoor safety was raised after the earthquake, though further safety measures can be advised. In the phase of post-earthquake emergency and restoration period, residents' management organizations play important roles, so that neighborhood activities to promote communication networks are important in urban environment with aging population.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.395-398
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• 2008

There was heavy rains that happened for 23 days consecutively in 2006. Many regions have suffered because of rains and among them In-Je and Pyung-Chang area are the most suffered areas at that time. I conducted field survey at those two regions. The case of other damaged regions also reviewed in this paper and volunteer activity of volunteer groups is reviewed. I intended to make clear the volunteer activity system through analysing need capacity of volunteers. Main suggestions are as below. In management system, the nexts are discussed. Improving the ability of village headmen and volunteer groups that manage relief stuffs at the first level and cooperating method with companies are discussed. Supporting system for isolated regions and necessity about developing operating manual are suggested. In education system, specialized education for different disaster areas, field orientation education, and training managerial positions are suggested. In supporting system, improving NDMS(National Disaster Management System), computerized program for volunteer management, insurance for volunteers, issuing a confirmation of volunteering activity, securement of emergency communication system, budget for prevention and donation are also suggested.

• Journal of the Korean Society of Safety
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• v.29 no.1
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• pp.59-63
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• 2014

Smoke is one of the most critical factor when escaping from the fire since it reduces visibility and interrupts finding emergency exit lights. Therefore, it is recommended that an evacuation simulation program should incorporate the smoke factor. In addition, it is suggested that the program should include not only the unilateral damage by the smoke but also the detour evacuation by risk communication. In this study, MAS (Multi Agent System)-based simulation program which incorporates the reduced walking speed by smoke and adopts the dispersion evacuation logic during escaping from the fire. To make comparison, a commercial evacuation program, Pathfinder was used. It was found that the simulation results of MAS (Multi Agent System)-based program is better than Pathfinder in terms of safe evacuation. It means that evacuation simulation need a additional evaluation categories that include not only quick evacuation time but also safe evacuee number.

• Journal of the Korean Institute of Navigation
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• v.20 no.2
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• pp.85-95
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• 1996

The purpose of this reserch is the development of 406MHz satellite EPIRB terminals which is used on Cospas/Sarsat system. This equipment is essencial facility in all vessel due to should be equipped according to GMDSS. This 406MHz satellite EPIRB needs high technology of complicated. Because, this is designed to operate stably with ultra-stability oscillator and with the low power consumption so that can operate continually for 48 hours by the contained battery. The development of this equipment is significant in the sides of acquirement of new technology on satellite communication fields. In this research, we investigated the international and domestic regulations of needed. Because this equipment is international system concerned with life of man. So, we designed the adequate hardwares and softwares from this research. From this research, we developed the equipment with appopriate capability for productions, and much more research is needed to develop the more small size more chip one for production.

• Journal of Korea Multimedia Society
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• v.19 no.8
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• pp.1404-1414
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• 2016

Cross-layer design is a concept, which captures the dependencies and interactions and enables information sharing among layers in order to improve the network performance and security. There are two key challenges in wireless networks, lossy features of links and power assumption of network nodes. Cross-layer design of congestion control and power allocation in wireless lossy networks has been studied in the existing literature; however, there has been no contribution proposed in the literature that exploits the path diversity. In this paper, we are motivated to develop a cross-layer design of congestion control and power allocation, which takes into account lossy features of wireless links and transmission powers of network nodes and can be implemented in a distributed manner. Numerical simulation is conducted to illustrate the performance of our proposed algorithm and the comparison with current alternative approaches.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2009.10a
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• pp.985-986
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• 2009

기존 연구에서 환자의 응급 상황이 발생했을 경우 병원에 도착하기 전 신속하고 정확한 체계적인 관리가 환자의 생명에 많은 영향을 미친다는 연구 결과가 보고되고 있다. 대부분의 어플리케이션에서는 많은 응급 상황에 대해 실시간 생체 신호들을 모니터링이 하기 위해 전송되는 생체 신호들은 많은 제한을 두고 있으므로 이런 생체 신호들을 무선 통신 기반에서 효율적인 설계가 요구되고 있다. 따라서 본 논문은 응급 상황의 이동 중에 환자의 생체 데이터와 환자의 영상을 실시간으로 전문가에게 전송하는 시스템을 설계함으로써 병원에 도착하기까지 숙련된 전문 의료 서비스 지원을 통해서 의사가 환자의 데이터를 분석 및 평가하고 치료 과정에서 환자의 처방을 즉각적으로 지시할 수 있다.