• Journal of KIISE:Information Networking
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• v.36 no.6
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• pp.514-527
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• 2009

Wireless sensor networks (WSNs) can be used in various applications for military or environmental purpose. Recently, there are lots of on-going researches for detecting and tracking the spread of continuous objects or phenomena such as poisonous gas, wildfires, earthquakes, and so on. Some previous work has proposed techniques to detect edge nodes of such a continuous object based on the information of all the 1-hop neighbor nodes. In those techniques, however, a number of nodes are redundantly selected as edge nodes, and thus, the boundary of the continuous object cannot be presented accurately. In this paper, we propose a new edge detection method in which edge nodes of the continuous object are detected based on the information of the neighbor nodes obtained via the Localized Delaunay Triangulation so that a minimum number of nodes are selected as edge nodes. We also define the sensor behavior rule for tracking continuous objects energy-efficiently. Our simulation results show that the proposed edge detection method provides enhanced performance compared with previous 1-hop neighbor node based methods. On the average, the accuracy is improved by 29.95% while the number of edge nodes, the amount of communication messages and energy consumption are reduced by 54.43%, 79.36% and 72.34%, respectively. Moreover, the number of edge nodes decreases by 48.38% on the average in our field test with MICAz motes.

• Journal of Korean Society of Environmental Engineers
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• v.34 no.12
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• pp.863-870
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• 2012

The market trends of automatic meter reading associated with smart water meters were investigated. Also, recent developments and field applications of key technology for automatic meter reading associated with smart water meters were analyzed. Smart water meters have been manufactured mostly in United States and Europe and have been expanded their business to Asia. Integrated water management system combining with the additional functions such as real-time consumption metering, cost notification, water conservation, leak detection, water quality monitoring, and flow control have been operated in automatic meter reading. Both water quality and quantity data measured from smart water meters and sensors were transferred to data concentration units through neighborhood area network, and then were transferred to integrated server through wide area network. The data transfer methods were determined by comprehensively considering urban scale, density of smart water meters, power supply and network topologies. Common data collection methods such as fixed network to data concentation units, vehicles drive by, people walk by, and drone fly by have been applied. The automatic meter reading associated with smart water meters are spread throughout the world, and both water and energy savings result in saving the money and reducing the greenhouse gases emission.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.4
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• pp.63-68
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• 2010

Utility-Pipe Conduit is, Housing and city effectively accommodate what they absolutely need power, communications, gas, pipeline, water supply, drainage, energy facilities etc, according to expansion of urban infrastructure are derived, several ways to solve problems in, collection facilities in place are maintained and managed facility. If Utility-Pipe Conduit is damaged, as well as national security, because their impact on society as a whole, by introducing large vulnerability in the fire prevention activities and suppression measures and disaster for our situation by introducing measures, comprehensive analysis of the fire risk, it shall establish fire prevention activities and suppression through analysis of Utility-Pipe Conduit design, institutional issues, the problem of fire protection facilities, fire spread phenomenon etc. Because of Utility-Pipe Conduit is an enclosed place, so incomplete combustion due to lack of oxygen supply that there are problem such dark smoke, carbon monoxide etc, toxic combustion products and heat generation and visual impairment is an issue difficult to enter. As well as fire prevention activities, the fire In light of the particularity of the under ground than above ground fire, so this phenomenon is weak fire fighting that fire to become effective fire fighting tactics, basically it is necessary difficulty softening, non-burn softening and prevent combustion expansion of the cable is installed on the Utility-Pipe Conduit, having to considering the specificity of the response command system and relevant organizations to establish an on-site, Structural identification and other information gathering required to record of Response agencies, keep air conditioning system 24 hours and strengthening Virtual Total Training of Response agen

• Korean Journal of Soil Science and Fertilizer
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• v.39 no.3
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• pp.136-143
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• 2006

The study was carried out to evaluate odor emission during storage time and quality of liquid slurry fertilizer along with three storage container types installed at farmer's fields in Cheorwon. Liquid slurry manure stored in the liquid-circulated or the air-injected tank was very homogeneous in concentration of nutritional elements because of well mixing operation, while nutritional concentration of the manure stored in the non-treated tank was significantly different from top to bottom in the tank, which may bring about partially irregular growth of plant after its application. The potential capacity of offensive odor emitted from liquid slurry manure stored in the liquid-circulated or the air-injected tank was much lower than that emitted from manure stored in the non-treated tank. Low potential capacity may less emit offensive odor after application of piggery liquid slurry on the field. The efficiency in oder to reduce odor emission from liquid manure was slightly higher in the liquid-circulated tank than the air-injected tank

• Membrane Journal
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• v.13 no.4
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• pp.246-256
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• 2003

For the olefin recovery from polyolefin off-gas, the permeation behaviors of olefins and nitrogen were investigated through three kinds of PDMS membranes - cross-linked PDMS membranes, a polysiloxaneimide membrane, and oligo-PDMS modified PDMS membranes. Their pure gas permeabilities were measured as a function of operation temperature(-20 to $50^{\circ}C$) and pressure(1 to 25 atm) with ethylene($C_2\;H_4$), propylene($C_3\;H_6$), butylene($C_4\;H_8$), and nitrogen($N_2$) gases. The permeabilities of olefins and nitrogen highly depended upon the nature of PDMS membranes. Among these membranes, cross-linked PDMS membranes showed stable and high olefin/nitrogen selectivities over a wide operation pressure range and further study in various test conditions. Their permeability of olefin and nitrogen were governed by the condensation temperature(solubility selectivity) and plasticization, not the order of the size(diffusivity selectivity) of gases, which matched well with the general permeation behavior of rubbery polymeric membranes for condensable and non-condensable gases. With increasing feed pressure or decreasing feed temperature, the permeabilities of more condensible olefins increase highly, presumably due to high solubility and plasticization, but that of non-condensible nitrogen decreases slightly and thus, the selectivities of olefin/nitrogen increase highly.

• 한국정보통신설비학회:학술대회논문집
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• 2004.08a
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• pp.282-290
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• 2004

80년대 초반에 등장한 퍼스널 컴퓨터에서부터 90년대에 급격히 확산된 클라이언트/서버 환경에 이르기까지 분산 컴퓨팅은 관리가 어렵다고 증명되었다. IBM의 Tivoli나 HP의 OpenView 등을 포함한 거대한 엔터프라이즈 관리 시스템 산업이 이러한 표면상의 극복하기 힘든 법칙처럼 여겨지는 것이 그 증거라고 하겠다. 이 후 무선의 개념이 등장했다. NOP World Technology가 Cisco사를 위해 2001년에 시행한 조사에 의하면 최종 사용자는 무선랜을 사용함으로써 생산성이 최고 22% 향상되었고 조사대상의 63%가 일상적인 직무에서 정확도가 향상되었다. 이 모든 것은 투자대비수익(ROI) 계산상 사용자 당 $550 해당한다. 현재 이동성과 IT 관리 기능의 딜레마를 동시에 고려하며 저렴한 몇몇 솔루션들이 소개되고 있다. 본 논문에서는 분산 컴퓨팅의 다음 진화 단계인 무선 네트워킹과 관련된 문제를 해결할 수 있는 혁신적이고 전체적인 접근법을 소개한다. 본 논문에서는 무선 컴퓨팅과 보안의 본질 및 무선랜이라는 새로운 컴퓨팅 패러다임으로 인하여 파생되는 운영과 관리의 어려움을 소개한다. 이러한 환경이 정의되면 본 논문은 이해하기 쉬운 5x5 레이어 매트릭스를 바탕으로 각 레이어의 독특한 본질을 고려한 혁신적인 무선랜 관리 방법에 대해 설명한다. 마지막으로 무선 네트워킹, 컨버젼스, 궁극적으로 분산 컴퓨팅만이 가지는 문제점을 해결할 수 있는 Red-M의 백 오피스 애플리케이션에 기반한 솔루션을 소개한다. 본 논문의 목표는 Red-M의 성공에 관한 두 가지 중요한 과정을 설명하고자 함이다. 이는 안전한 무선 네트워크 제어에서 비롯되는 무선 환경이 약속하는 장점들을 고루 제공하는 것과 나쁜 의도의 사용자를 차단할 뿐 아니라 올바른 사용자와 또한 나머지 일반 사용자를 총체적으로 관리할 수 있는, 안정적이고 확장 가능하며 직관적인 시스템을 제공하는 것이다.가 생성된다. $M_{C}$에 CaC $l_2$를 첨가한 경우 $M_{C}$는 완전히 $M_{Cl}$ 로 전이를 하였다. $M_{Cl}$ 에 CaC $l_2$를 첨가하였을 경우에는 아무런 수화물의 변화는 발생하지 않았다. 따라서 CaS $O_4$.2$H_2O$를 CaC $O_3$및 CaC $l_2$와 반응시켰을 때의 AFm상의 안정성 순서는 $M_{S}$ < $M_{C}$< $M_{Cl}$ 로 된다.phy. Finally, Regional Development and Regional Environmental Problems were highly correlated with accommodators.젼 공정을 거쳐 제조된다는 점을 고려할 때 이용가능한 에너지 함량계산에 직접 활용될 수는 없을 것이다.총단백질 및 AST에서 시간경과에 따른 삼투압 조절 능력에 문제가 있는 것으로 보여진다.c}C$에서 5시간 가열조리 후 잔존율은 각각 84.7% 및 73.3%였고, 질소가스 통기하에서는 잔존율이 88.9% 및 81.8%로 더욱 안정하였다.8% 및 12.44%, 201일 이상의 경우 13.17% 및 11.30%로 201일 이상의 유기의 경우에만 대조구와 삭제 구간에 유의적인(p<0.05) 차이를 나타내었다.는 담수(淡水)에서 10%o의 해수(海水)로 이주된지 14일(日) 이후에 신장(腎臟)에서 수축된 것으로 나타났다. 30%o의 해수(海水)에 적응(適應)된 틸라피아의 평균 신사구체(腎絲球體)의 면적은 담수(淡水)에 적응된 개체의 면적보다 유의성있게 나타났다. 해수(海水)에 적응(適應)된 틸라피아의 신단위(腎

• Fire Science and Engineering
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• v.30 no.6
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• pp.48-56
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• 2016

A crude oil leakage from a large atmospheric storage tank occurred on 4 April 2014 at 14:50 in Ulsan City, while storing the crude oil in the tank. Emergency Rescue Control Group was deployed in the scene. The company, Fire Service Headquarters and associated agencies got together in Command Post (CP) for discussing an effective corresponding strategy. Many solution plans were drafted in the debate such as power down, stopping the facilities, checking the density of inflammable gas, suppressing oil evaporation, moving the leaked crude oil to a nearby tank and a processing plant and avoiding marine pollution. All the solutions were carried out in cooperation with several agencies and partners. The oil leakage accident was successfully settled up within the process of responding, The Fire Service Headquarters and the company thought that the most important thing was the suppression of oil evaporation and the elimination of ignition source. With Fire Service Headquarters and several agencies' every effort, an explosion and a fire didn't occurred in the scene. This study suggest the improvement of the operating system in Emergency Rescue Control Group in case of petroleum leakage, explosion and fire accidents of atmospheric storage tank, different from a ordinary disaster. Assuming that petroleum leakage in atmospheric storage tank develop the explosion and fire accidents, the spreading speed of the flame and the burning time was experimented and compared with each other. Furthermore, this study concentrates on the effective field response plan prepared for the afterward explosion and fire accidents from petroleum leak in a storage tank, with the database experimented and analyzed in accordance with the angle of radiation in the foam nozzle and the pressure of pumping in a fire engine.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2002.11a
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• pp.363-369
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• 2002

가정 내에서의 초고속망 이용이 활성화되면서 가정 내에서의 활동은 매우 다양하고 복잡하며 그에 따른 서비스도 여러 가지 형태가 존재한다. 외부 인터넷망과 연동되는 홈 네트워크의 개념이 생기기 전부터 흠 오토메이션, 홈시큐리티 등의 서비스를 제공하기 위한 고립적인 형태의 망과 서비스 제공 시스템이 있었다. 월드 와이드 웹 서비스를 기본으로 한 인터넷의 폭발적인 활성화와 고속 인터넷망의 확산에 따라 가정 내에서 제공되는 서비스를 인터넷과 연계시키려는 시도가 보편화되었고 가정 내에서 사용되는 독립적인 기기들을 인터넷에 연결하여, 외부의 정보를 이용해서 활용하거나, 가전내의 기기들을 외부에서 액세스할 수 있게 되었다. 이렇게 하여 보다 풍부한 서비스를 제공하고, 사용상의 시간적인 제약을 완화할 수 있다. 예들 들어 인터넷상에서 조리법을 전송받아 전자레인지를 작동할 수 있으며, 외부에서 잘못 켜둔 가스밸브를 잠글 수도 있다. 가정 내에서 wrhd되던 이러한 서비스들은 서로 다른 하드웨어와 통신방법을 사용하고 있어, 이러한 서비스를 통합하여 운영, 관리할 수 있도록 하는 흠 서버의 개념이 대두되었다. 외부 인터넷 망과 연계된 흠 오토메이션, 홈 시큐리티등을 제공할 수 있는 기반이 마련되었고, 가정 내에서 독립적으로 제공되던 서비스들을 단일 홈 서버를 통해서 관리하려는 시도가 진행되었다. 그러나 홈 서버는 개발하는 업체의 보유기술에 따라 중심기능은 약간씩 차이를 보이고 있다. 홈 서버 응용 영역은 전문 지식을 소유한 인력과의 연계가 필요하고, 다양한 서비스 영역 행위가 아주 복잡하기 때문에 이들을 연결해 주는 자치 시스템을 필요로 한다. 또한 홈 서버 서비스 영역에서 정보는 각 영역 전문가가 가진 지식의 전달을 필요로 하기 때문에, 지식을 주고받는 멀티 에이전트의 시스템의 활용 영역으로 적당하다. 멀티 에이전트 시스템은 분산된 환경에서 에이전트간에 에이전트 통신 언어를 사용해서 대화를 하기도 하고, 상호 협력하는 에이전트들로 구성된 시스템을 뜻하며 흠 서버처럼 동적이고 고도의 자치성을 요구하는 영역에 적당하다. 멀티 에이전트 플랫폼으로는 FIPA(Foundation for Intelligent Physical Agents)가 제시한 에이전트 표준 플랫폼이 1997년부터 2000년에 이르기까지, 계속적으로 변화, 발전하고 있다. 본 연구는 FIPA에서 제시하는 플랫폼을 기반으로 홈 서버에 정보가전을 제어하는 에이전트를 두고 외부에서 다른 에이전트가 홈 서버에 위치하는 에이전트와의 통신을 통하기 정보가전을 지능적으로 제어하도록 하였다. 정보가전 에이전트는 가정 내 가전제품을 외부에서 제어하기 위한 에이전트이다. 단순한 관리가 아닌 에이전트로 하여금 지능적으로 가전제품 관리를 하게 한다. 정보가전 에이전트는 홈 서버에서 작동하는 에이전트와 PDA에서 작동하는 에이전트로 구성된다. 정보가전 에이전트는 전력량, 수도 사용량 제어와 가전제품 제어 기능과 보안 관련 서비스를 제공한다. 두 에이전트는 FIPA에서 정의된 규격에 맞게 만들어지기 때문에 FIPA명세서를 따르는 다른 에이전트와 자유로운 통신이 가능하다.

• Fire Science and Engineering
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• v.31 no.6
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• pp.74-82
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• 2017

Fires in buildings built using sandwich panels are difficult to extinguish, and the damage caused by the fire spreading through the inner core material is extensive. Sandwich panels consist of a nonflammable material on both sides of an insulation material. The types of insulation material include organic and inorganic insulation materials, but the former are used in more than 80% of the case. Organic insulation is economically advantageous compared to inorganic insulation, but it is vulnerable to fire. Therefore, the damage caused by sandwich panel fires is higher than that for general fires. In the case of the noxious gas analyzer test, the panel is tested with three round holes having a diameter of 25 mm, in order to determine the risk of the core material, but the cone calorimeter test is carried out using a sandwich panel. In this study, the cone calorimeter test was conducted to examine the fire risk of the composite material when heated on a nonflammable surface, exposed to the core material through a hole, and heated directly the core material. The type of organic insulation employed was flame retardant EPS (Expanded Polystyrene), and the test specimens were tested in three types of sandwich panel, a perforated sandwich panel and single core material. The purpose of this study is to propose a method of measuring the fire risk of the core materials of composite materials using the cone calorimeter test.

• Tunnel and Underground Space
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• v.28 no.1
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• pp.38-58
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• 2018

The ventilation system plays a crucial role in underground mine safety. The main objective of the ventilation system is to supply sufficient air to dilute the contaminated air at working places and consequently provide tenable environment during the normal operation, while it also should be capable of controlling the fire propagation and facilitate rescue conditions in case of fire in mines. In this study, a smoke control fan was developed for the auxiliary ventilation as well as the fire smoke exhaust. It works as a free-standing auxiliary fan without tubing to dilute or exhaust the contaminated air from the working places. At the same time, it can be employed to extract the fire smoke. This paper aims to examine the smoke control efficiency of the fan when combined with the current ventilation system in mines. A series of the site experiments and numerical simulations were made to evaluate the fan performance in blind entry development sites. The tracer gas method with SF6 was applied to investigate the contaminant behavior at the study sites. The results of the site study at a large-opening limestone mine were compared with the CFD analysis results with respect to the airflow pattern and the gas concentration. This study shows that in blind development entry, the most polluted and risky place, the smoke fan can exhaust toxic gases or fire smoke effectively if it is properly combined with an additional common auxiliary fan. The venturi effect for smoke exhaust from the blind entry was also observed by the numerical analysis. The overall smoke control efficiency was found to be dependent on the fan location and operating method.