• 센서학회지
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• 제23권4호
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• pp.266-271
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• 2014

Chemical sensors are used in various industrial facilities such high-risk and prevent the leakage of substances, important in life and environmental protection and the safe use of industry, used for management. In particular, high-temperature environments such as power generation equipment of the rotating part due to leakage generated by the various oil, power plants Shut Down, fire, work environment (exposure to various chemical solution and gas leak) and various water, air and soil pollution causes. Thus, over the long term through various channels such as crops and groundwater contamination caused by the slow, serious adverse effect on the ecosystem. In this paper, synthetic lube oil and high pressure hydraulic fluid leakage and immediately detect a new Printed Electronic implementation of technology-based film-type sensors, and its performance test. Thus, industrial accidents and environmental pollution and for early detection of problems, large accidents can be prevented. Experimental results of the synthetic lube oil and high pressure hydraulic fluid solution after the contact time depending on the experiment and the oil solution of the sensor material of the conductive porous PE resistance value by a chemical reaction could be confirmed that rapid increase. Also implemented in the film-type oil sensor electrical resistance change over time of the reaction rate and the synthetic lube oil is about 2 minutes or less, the high pressure hydraulic fluid is less than about 1 minute was. Therefore, more high-pressure hydraulic fluid such as a low volatility synthetic lube oils are the resistance change and the reaction rate was confirmed to be the slowest.

• 한국생산제조학회지
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• 제22권6호
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• pp.976-981
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• 2013

This aims to examine experimentally the absorption behavior and strength of circular CFRP members with different stacking configurations on exposure to a separate impact velocity. In addition, considered the dynamic characteristics. Circular and square CFRP members were prepared from 8-ply unidirectional prepreg sheets stacked at different angles ($0^{\circ}/90^{\circ}$ and $90^{\circ}/0^{\circ}$, where the $0^{\circ}$ direction coincides with the axis of the member) and interface numbers (2, 4, and 6). Based on the collapse characteristics of the circular CFRP members. In this study, for the circular members, the impact energies at crosshead speeds of 5.52 m/s, 5.14 m/s, and 4.57 m/s are 611.52 J, 529.2 J, and 419.44 J (at circular members), respectively. Likewise, for the square members, the impact energies at crosshead speeds of 2.16 m/s, 1.85 m/s, and 1.67 m/s are 372.4 J, 274.4 J, and 223.44 J (at square members).

• 산업경영시스템학회지
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• 제40권1호
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• pp.11-21
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• 2017

Artillery fire power due to effectiveness which is hard to predict well-planned and surprising attack can give a fear and shock to the personnel and is a very core weapon system and takes a critical role in wartime. Therefore in order to maximize operational effectiveness, Army required protecting artillery and takes a quick attack action through rapid construction of artillery's positions. The artillery use artillery's position to prevent exposure by moving to other position frequently. They have to move and construct at new artillery's positions quickly against exposing existed place by foe's recognition. These positions should be built by not manpower but engineering construction equipment. Because artillery positions have to protect human and artillery equipment well and build quickly. Military engineering battalion have lots of construction equipment which include excavator, loader, dozer, combat multi-purposed excavator, armored combat earthmover dump truck and so on. So they have to decide to optimal number of Team combining these equipments and determine construction sequence of artillery's position in operational plan. In this research, we propose to decide number of Team efficiently and allocate required construction's positions for each Team under constraints of limited equipments and time. To do so, we develop efficient heuristic method which can give near optimal solution and be applied to various situation including commander's intention, artillery position's priority or grouping etc. This heuristic can support quick and flexible construction plan of artillery positions not only for using various composition's equipment to organize Teams but also for changing quantity of positions.

• 한국산업보건학회지
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• 제10권2호
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• pp.150-164
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• 2000

This study was conducted at occupational health laboratories in Seoul and Gyunggi district area from December, 1999 to January, 2000. The main purpose of this study was to survey the actual condition of safety and health by questionnaire and checklist and to assess the performance of fume hoods and the airborne exposures to chemicals in the laboratories. The chemicals in the cabinet were not classified by hazardous properties and the compressed gases were not stored safely. The prevalences of laboratories having first aid kits, fire extinguishers, and safety showers were found to be 18%, 55%, and 9%, respectively. Most laboratory workers were not educated for safety and health. Also, there was no performance evaluation for hazards and risks. The fume hoods in laboratories had not been annually inspected by checklist and the face velocity had been checked more than one time in the previous year for only 18% of them. Five percent of fume hoods had the face velocity more than 4.0 m/sec and 17% had no capture performance. Detected organic solvents were methylenechloride, acetone, ethylbenzene, isopropanol, xylene, methylisobutylketone, trichloroethylene, and toluene. The concentrations of organic solvents were much less than the occupational exposure limits proposed by the Ministry of Labor in Korea. This study showed that the actual condition of safety and health was not appropriate for laboratory workers. It is recommended that laboratory workers should be educated for the treatment and storage of hazardous chemicals and compressed gases to improve the working environment of the occupational safety and health laboratories.

• 한국ITS학회 논문지
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• 제16권1호
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• pp.166-175
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• 2017

최근 아시아 태평양 지역의 항공교통량이 증가하는 가운데 한반도 주변국의 화산분화로 인하여 항공로에 많은 영향을 줄 것으로 예상된다. 이에 화산분화로 인한 항공산업의 손실을 줄이기 위하여 국내의 항공현황 및 항공로를 분석하고, 한반도 주변국의 화산분화 시나리오를 기반으로 항공교통에 대한 피해정도를 예측할 필요가 있다. 이를 위한 관련 화산재, 항공정보를 수집하고 처리하는 프레임워크가 필요하다. 항공로와 공항의 폐쇄에 따른 항공교통 피해를 계산하기 위해 GIS geometry analysis기법을 사용하여 항로, waypoints, 공항의 화재 영향 여부를 판별하는 체계를 제시하였다. 화산이 분화하였을 때 타 분야와는 달리 항공에 대한 영향은 바로 집계가 가능한 특징이 있다. 이를 위해 실시간 항공정보의 수집과 저장은 매우 중요한 요소로 화산재대응시스템의 구성이 중요한 역할을 할 것으로 기대된다.

• Journal of Preventive Medicine and Public Health
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• 제28권1호
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• pp.1-12
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• 1995

Diatomaceous earth, quarried from the remains of aquatic plants deposited millions of years ago, continues to be a very important raw material with many industrial uses. In its natural state, diatomaceous earth is an amorphous silica with no crystalline pattern. For many uses, however, it is calcinated and calcination converts a portion of the amorphous silica to a crystalline form, cristobalite which is far more fibrogenic. In a factory which produces calcinated diatomaceous earth, seven workers were proved as pneumoconiosis on 1991 and 1992. Authors reviewed medical chart and current status of them. Authors also examined thirty one subjects from the factory with questionnaire, physical examination, spirometry and chest radiography on August 13th 1993. The radiographs were independently interpreted by two radiologists and their findings were classified by International Classification of Radiography of Pneumoconiosis(ILO, 1980). Total and respirable dust of diatomaceous earth were measured on October 1993. The results were as follows; 1. Of 31 workers, 6 (19.4%) were diagnosed as diatomaceous earth pneumoconiosis. There was an increasing tendency in prevalence of pneumoconiosis as the duration of dust exposure gets longer. 2. There were no significant differences in age, smoking rate, alcohol drinking rate, and pulmonary function test results between cases and non-cases. 3. The means of total dust exposures at flour manufacturing, fire brick grinding and packaging, ceramic raws packaging processes exceeded Korean and ACGIH standards, $10mg/m^3$. Above results suggest that engineering controls, periodic environmental and medical surveillance are important for preventing pneumoconiosis in the diatomite factory.

• 한국구조물진단유지관리공학회 논문집
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• 제19권6호
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• pp.63-71
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• 2015

본 연구는 섬유를 혼입한 고강도 콘크리트의 온도 변화에 따른 내화특성 분석에 관한 연구로 고강도 콘크리트에 고온이 가해질 경우 발생되는 폭렬현상에 대하여 방지효과가 있는 것으로 알려져 있는 하이브리드섬유와 강섬유를 함께 혼입하여 만든 복합섬유를 사용하여 온도 변화($100{\sim}800^{\circ}C$)에 따른 고강도 콘크리트의 내화특성 및 역학적 메커니즘을 분석하였다. 또한 본 논문에서는 고강도 콘크리트 구조물에서 가장 문제가 되는 폭렬현상을 막는 대책 중의 하나인 섬유 혼입을 통한 방법을 사용하여 SEM 및 XRD 분석 등의 방법으로 고온을 받은 고강도 콘크리트의 열적 특성 및 역학적 특성을 규명하고자 하였다.

• 대한불안의학회지
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• 제8권2호
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• pp.86-92
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• 2012

Objective : This study investigated the relationship between the resilience and posttraumatic stress symptoms, as well as comorbid symptoms in firefighters. Methods : We collected 764 firefighters, who worked at six fire department stations in Gangwon-do. We investigated the impact of event scale-revised (IES-R), the life events checklists (LEC), Connor-Davidson resilience scale (CD-RISC), Beck depression inventory (BDI), state trait anxiety inventory (STAI) and alcohol use disorder identification test (AUDIT). Full PTSD groups, partial PTSD groups and non-PTSD groups, which were classified by IES-R scores, were compared in the LEC, CD-RISC, BDI, STAI and AUDIT, ; multiple linear regression analyses were done for independent predictors of variables. Results : Of the 764 firefighters, there were significant differences in LEC (p<0.001), CD-RISC (p<0.001), BDI (p<0.001), and AUDIT (p=0.001) among the full PTSD groups, partial PTSD groups and non-PTSD groups. However, STAI did not show significant difference among three groups. In multiple regression analysis, CD-RISC (${\beta}=-0.168$, p<0.001), LEC (${\beta}=0.211$, p<0.001) and AUDIT (${\beta}=0.115$, p=0.001) were significant predictors for IES-R. Conclusion : The results of the present study suggested that resilience might be a protective factor in PTSD and comorbid symptoms of PTSD.

• 산업경영시스템학회지
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• 제36권3호
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• pp.142-149
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• 2013

Among ammunitions which are stored in a war field, the lifespan of propelling gunpowder is affected by storage environment such as storage temperature, humidity, and exposure to sunlight. These are because Nitrocellulose (NC) which is the main component of propelling gunpowder can be naturally disassembled to unstable substances similar with other nitric acid ester. We can't prevent it fundamentally from being disassembled, but to restrain induction of automatic disassembly by decomposition product, a decomposition product ($NO_2$, $NO_3$, and $HNO_3$) and tranquillizer DPA (Diphenylamine), having high reactivity, are added into a propellant. For this, it will decrease the velocity of tranquillizer which can also affect the velocity of producing the decomposition product of NC, storage temperature or humidity of propelling gunpowder is higher, drop of tranquillizer content is much faster. Therefore, to extend storage lifespan of propelling gunpowder, it is really important to control storage temperature or humidity inside the magazine. Hereupon, according to the manufacture of small scale model magazine and the result of performing experiments and measuring variation of inside temperature (storage temperature), using roof types that have a steel slate structure of magazine among ground magazines, this research shows the differences in details.

• 한국가스학회지
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• 제17권4호
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• pp.9-17
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• 2013

Butanethiol은 황화수소, 메틸메르캅탄, 황화메틸 등과 함께 유해성이 높으며 대표적인 악취물질로 알려져 있으나 노출 농도별 생체에 미치는 영향 등 유해성 평가 자료가 매우 부족하여 실험동물을 이용 흡입독성 연구를 통하여 유해농도와 사람에 미치는 영향을 예측하고자 연구하였다. Butanethiol은 무색 투명액체로, 인화점 $-23^{\circ}C$로 화재위험성이 강한물질로 끓는점 $84-85^{\circ}C$, 증기압($25^{\circ}C$) 80.71 mmHg, 어는점 $-140.14^{\circ}C$의 특성을 가지고 있다. 실험동물인 SD rats와 전신흡입노출 챔버를 이용 반수치사농도를 시험한 결과 $LC_{50}$은 2,500 ppm (9.22mg/L)이상으로 이는 고용부 고시 제2012-14호[11]의 유해물질 분류기준 급성독성물질 구분 4 (10${\leq}20$ mg/L) 이상의 물질에 해당되었다. 또한 0, 25, 100, 400 ppm, 일일 6시간, 주 5일, 13주 반복 노출한 결과에서는 25 및 400 ppm군에서 체중의 유의성(p<0.01., 0.001) 있는 저하를 포함 4사료섭취량 변화, 안 자극, 수컷군의 운동성변화, 혈액 및 혈액생화학적 병변이 있었으며, 장기중량에서도 수컷의 경우 25, 100, 400 ppm군과 암컷의 400 ppm군에서 신장, 간장, 흉선, 폐장 등에서 유의성 (p<0.05) 있는 변화가 있어 무유해영향농도 (NOAEL)는 암 수 모두 25 ppm (0.092 mg/L) 이하로 평가되었다.