• 한국산업보건학회지
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• 제4권1호
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• pp.81-95
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• 1994

This study was performed in a diatomite factory where silicosis had been found at October, 1993. The major objectives were to evaluate worker exposure to diatomaceous earth and to present engineering control methods for workplace management. Total and respirable dust of diatomaceous earth were measured. Size distribution of dust was analyzed by applying the multiple diffraction method. Also crystalline silica in respirable dust samples was analyzed qualitatively by X-ray diffraction. The suitable Local Exhaust Ventilation systems for that factory were recommended. The results were as follows. The airborne total and respirable dust concentrations by exposure groups showed approximate normal distribution. The means of total dust exposures at flour maufacturing, fire brick grinding and packaging, ceramic raws packaging processes exceeded Korean and ACGIH standards, $10mg/m^3$. The means of total and respirable dust concentrations to high exposure groups were 6.8 and 3.9 times higher than those of low expousre groups, respectively. The size distribution of diatomaceous earth dust was lognormal with a median diameter of $7.07{\mu}m$(range, $0.10-60.0{\mu}m$) and with a geometric standard deviation of 1.43. The crystalline silica in respirable dust samples was identified to quartz and cristobalite and/or tridymite. Above results suggest that engineering controls and periodic environmental and medical surveillances will be important for preventing silicosis in the diatomite factory.

• 한국안전학회지
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• 제33권1호
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• pp.66-72
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• 2018

This study analyses the types, related operations, facilities, and causes of chemical accidents in Korea based on the RISCAD classification taxonomy. In addition, human error analysis was carried out employing different human error classification criteria. Explosion and fire were major accident types, and nearly half of the accidents occurred during maintenance operation. In terms of related facility, storage devices and separators were the two most frequently involved ones. Results of the human error-based analysis showed that latent human errors in management level are involved in many accidents as well as active errors in the field level. Action errors related to unsafe behavior leads to accidents more often compared with the checking behavior. In particular, actions missed and inappropriate actions were major problems among the unsafe behaviors, which implicates that the compliance with the work procedure should be emphasized through education/training for the workers and the establishment of safety culture. According to the analysis of the causes of the human error, the frequency of skill-based mistakes leading to accidents were significantly lower than that of rule-based and knowledge based mistakes. However, there was limitation in the analysis of the root causes due to limited information in the accident investigation report. To solve this, it is suggested to adopt advanced accident investigation system including the establishment of independent organization and improvement in regulation.

• 디지털융복합연구
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• 제18권2호
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• pp.103-110
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• 2020

지난해 발생한 KT 아현지사 화재사건은 안전이 담보되지 않는 한 5G 초연결 네트워크가 우리에게 장밋빛 미래 대신 잿빛으로 물든 우울한 현실이 될 수 있음을 보여준 사건이었다. 지난 1999년 우리가 밀레니엄 버그의 우려에도 불구하고 새로운 밀레니엄을 큰 사고 없이 평온하게 맞이할 수 있었던 것은 신기술 발전이 가져온 위험요소를 사전에 예측하고 이를 막기 위한 적극적인 투자와 노력을 기울였기 때문이다. 따라서 5G 초연결 네트워크 사회의 가장 큰 위험 요소로 부상한 '네트워크의 단절'을 막기 위한 관심과 노력은 지금부터 시작되어야 하며 그 출발선은 5G 초연결 네트워크의 공공재적 성격과 필수 기본 서비스로서의 역할과 기능에 주목해 5G 서비스의 공익성을 제고하는 방안을 모색하는 일이 되어야 할 것이다.

• 한국환경복원기술학회지
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• 제17권3호
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• pp.13-33
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• 2014

The purpose of this study is to offer the raw data for establishing the management and restoration plan by objective surveying and analysing the flora distributed in Seoak District, Gyeongju National Park, Korea. The flora summarized as 411 taxa including 92 families, 285 genera, 363 species, 2 subspecies, 41 varieties and 5 forms. The rare plants designated by Korea Forest Service were 2 taxa including Exochorda serratifolia and Potentilla discolor. The Korean endemic plants were 3 taxa including Philadelphus schrenkii, Lespedeza maritima and Weigela subsessilis. The specific plants by floristic region were 16 taxa including Asplenium sarelii, Pyrrosia petiolosa, Vitex negundo var. incisa and so forth. The target plants adaptable to climate change were 2 taxa including Lespedeza maritima and Carpesium macrocephalum, and the plants with approval for delivering oversea were 4 taxa including Exochorda serratifolia, Glycine soja, Lespedeza maritima and Weigela subsessilis. The naturalized plants were 51 taxa including Phytolacca americana, Viola papilionacea, Lamium purpureum and so forth. The invasive alien plants were 3 taxa including Ambrosia artemisiifolia, Aster pilosus and Lactuca scariola. NI(Naturalized Index) was 12.4% of all 411 taxa of surveyed flora in this study and UI(Urbanized Index) was 15.9% of all 321 taxa of naturalized plants in Korea. Potentilla discolor in rare plant, Philadelphus schrenkii in endemic plant and Dictamnus dasycarpus in specific plant were established the conservation plan. Whereas, invasive alien plants such as Ambrosia artemisiifolia, Aster pilosus and Lactuca scariola should be removed as soon as possible. The damaged sites in Seoak District were divided between wildfire area and farmland. To restore a forest fire site, we will have to apply a natural renewal and community planting. In case of farmland, we will have to do ecological planting using native species and constrcut a forest wetland.

• 한국재난정보학회 논문집
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• 제13권2호
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• pp.267-275
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• 2017

본 연구는 재해현장에서 발생한 다양한 형태의 디지털 증거물을 채집 분석하는데 있어 디지털 포렌식 기법에 입각하여 효율적으로 재해 현장 디지털 데이터를 채증할 수 있는 e-Forensic 툴 개발에 관한 것이다. 현장에서 채집한 다양한 디지털 증거물이 법적 증거물로 채택되기 위해서는 디지털 증거물이 위변조가 없는 원본과 동일한 상태임을 입증해야만 하는데 이를 본 e-Forensic툴을 이용하여 검증하였다. 이 툴을 활용하면, 현장 수사 중 디지털 파일을 증거로 수집하는 경우에 현장에서 바로 해시값을 생성, 암호화된 디지털 파일에 부가함으로써 디지털 파일의 원본과 사본의 동일성을 보장하고 현장 증거의 무결성을 향상시킬 수 있는 효과가 있음을 증명하였다.

• 한국태양에너지학회 논문집
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• 제32권4호
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• pp.9-16
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• 2012

Nanofluids using Carbon Nanotubes have a excellent thermal characteristic. In this study, for increasing the efficiency of solar collector, the thermal conductivity and viscosity of Ethanol-Oxidized Multi-walled Carbon Nanofluids were measured. Nanofluids were manufactured by ultra-sonic dispersing Oxidized Multi-walled Carbon Nanotubes(OMWCNTs) in ethanol at the rates of 0.0005 ~ 0.1 vol%. The thermal conductivity and viscosity of manufactured nanofluids were measured at the low temperature($10^{\circ}C$), the room temperature($25^{\circ}C$) and the high temperature($70^{\circ}C$). For measuring thermal conductivity and viscosity, we used transient hot-wire method and rotational digital viscometer, respectively. As a result, under given temperature conditions, thermal conductivity of the 0.1 vol% nanofluids improved 33.74% ($10^{\circ}C$), 33.14% ($25^{\circ}C$) and 32.36% ($70^{\circ}C$), and its viscosity increased by 37.93% ($10^{\circ}C$), 31.92% ($25^{\circ}C$) and 29.42% ($70^{\circ}C$) than the base fluids.

• 산업융합연구
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• 제18권1호
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• pp.79-85
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• 2020

최근 원격조종과 자율조종이 가능한 무인항공기(RPAS:Remotely Piloted Aircraft System)가 택배 드론, 소방드론, 구급 드론, 농업용 드론, 예술 드론, 드론 택시 등 각 산업 분야와 공공기관에서의 관심과 활용이 높아지고 있다. 자율조종이 가능한 무인드론의 안정성 문제는 앞으로 드론 산업의 발달과 함께 진화하면서 해결해야 할 가장 큰 과제이기도 하다. 드론은 자율비행제어 시스템이 지정한 경로로 비행하고 목적지에 정확하게 자동 착륙을 수행할 수 있어야 한다. 본 연구는 드론의 센서와 GPS의 위치 정보의 오류를 보완하는 방법으로서 착륙지점 영상을 통해 드론의 도착 여부를 확인하고 정확한 위치에서의 착륙을 제어하는 기법을 제안한다. 서버에서 도착지 영상을 구글맵 API로부터 수신받아 딥러닝으로 학습하고, 드론에 NAVIO2와 라즈베리파이, 카메라를 장착하여 착륙지점의 이미지를 촬영한 다음 이미지를 서버에 전송한다. Deep Learning으로 학습된 결과와 비교하여 임계치에 맞게 드론의 위치를 조정한 후 착륙지점에 자동으로 착륙할 수 있다.

• 대한임상독성학회지
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• 제5권2호
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• pp.106-111
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• 2007

Purpose: Inadequate hospital stocking and unavailability of essential antidotes is a worldwide problem. The purpose of this study was to determine the adequacy of antidote stocks in Korean hospitals based on a modified version of US antidote stocking guidelines. Methods: Both written and telephone surveys to collect information on hospital demographics and antidote stocking were given to the emergency departments or hospital pharmacies of 117 hospitals with emergency medical centers. The twenty antidotes included in the survey were taken from year 2000 US antidote stocking guidelines, except for activated charcoal and black widow spider antivenin. Antidote stocks were compared by hospital size, geographic location, and type of emergency medical center. Results: Complete responses were received from all hospitals. A mean of $12.4{\pm}2.9$ antidotes were adequately stocked per hospital. All hospitals stocked atropine, $CaCl_2$ naloxone, and sodium bicarbonate. However, digoxin Fab fragment (16%), cyanide kits (15%), EDTA (10%), BAL (9%), and fomepizole (1%) were not uniformly stocked. Large and teaching hospitals were significantly more likely to stock greater numbers of antidotes. Conclusions: Korean hospitals as a group do not have adequate antidote stocks. Korean stocking guidelines and an antidote management system are recommended in order to correct these deficiencies.

• 대기
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• 제20권2호
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• pp.173-186
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• 2010

The impact of the precipitation has been focused on losses in social and economical sectors. However, as growing the concerns of the future water shortage caused by the climate change, the precipitation should be consider in various views for an effective planning in the water resource management. A precipitation case occurred from 20 to 21 April 2009 was recorded as a welcome rain because it reduced the severe drought continued in Korea from winter season of 2008. In this study, economic values of the event was calculated with positive aspects in various sectors. The estimation is based on four major parts such as a secure of water resources, the improvement of air quality, the decrease of forest fires, and the reduction of the drought impact. The water resources only considered inflow waters into dams and the reservoirs managed by Korean public institutions and their economic values accounts for 5.92 billion won. Decreases of four air pollutants($PM_{10}$, $NO_2$, CO, and $SO_2$) were considered as the positive effects of the rainfall and estimated 175.4 billion won. The preventive effect of the forest fire after the rainfall results in 0.48 billion won. Finally, the rainfall during the drought period is effective to reduce the social costs of 108.65 billion won. Although the economic values estimated in this study explain parts of the positive effects of the precipitation, it can help to develop a comprehensive and systematic valuation system for the whole process of the precipitation. For doing this, various rainfall types should be analyzed in social-economic terms including economics, environments and hydrology.

• 한국ITS학회 논문지
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• 제9권1호
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• pp.9-18
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• 2010

산악지형이 많은 우리나라는 자연환경 여건상 터널 수요가 많고 안전한 운영을 보장 할 수 있는 터널 유고감지 시스템에 대한 필요성도 커지고 있다. 본 논문에서는 터널 내 유고 상황을 실시간으로 감지하여 터널 사무소에 전달 터널의 안전한 운영을 도울 수 있는 터널 유고감지 시스템을 제안 하였다. 제안한 시스템은 차 영상 기법과 같은 단순한 영상 분석 알고리즘을 사용하여 시스템의 신속성을 높였으며 유고의 종류 보다는 유고상황의 발생여부를 정확히 판단하데 중점을 두어 시스템의 정확성도 확보하였다. 또한 영상 분석 장치 한 대당 네 대의 카메라를 수용할 수 있게 함으로써 시스템의 비용적인 측면도 고려하였다. 그리고 카메라의 대수에 따라 영상분석 장치를 추가함으로써 카메라 대수에 관계없이 시스템의 확장성을 용이하게 하였으며 터널 유고상황 정보를 웹에서도 접근 가능하게 하여 원격지의 다른 터널 시스템과의 연동 등의 추가 확장성도 고려하였다. 구현된 시스템을 실제 터널에서 실험한 결과 터널 내에서 발생한 장애물, 정지 사고차량, 차량 정체 지체, 사람 이륜차, 연기 화재, 조명 이상, 역 주행 등의 유고상황을 모두 실시간으로 정확히 감지하였다.