• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.155-155
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• 2020

최근 전 세계적으로 기후변화 및 이상기후로 인해 홍수, 가뭄과 같은 수자원과 관련된 재해들의 빈도가 증가하고 있는 추세이다. 가뭄은 발생 시작 및 종료 시기가 명확하지 않고, 그 피해가 광범위한 특징으로 인해 농업분야에 직접적인 피해를 주고 있으며, 농산물 생산성 및 안정적인 농업용수 확보에 큰 영향을 미치고 있다. 과거 가뭄을 해석하기 위해서는 일반적으로 강수량, 가뭄지수 등 단일지표를 활용하여 가뭄을 평가하였으나, 최근 선제적인 가뭄대응을 위해 다양한 인자들을 종합하여 판단하는 취약성 평가 (Vulnerability Assessment) 개념을 도입하였다. 농업가뭄 취약성은 IPCC (Intergovernmental Panel on Climate Change)에서 기상 및 수문학적 가뭄에 의한 작물 생산 피해 및 가축의 피해를 동반할 수 있는 가능성으로 정의한다. 본 연구에서는 농업용 저수지 중심의 농업용수 기반 취약성 평가 항목을 선정하여 농업가뭄 취약지도를 작성하였다. 민감도, 노출도 및 적응능력 개념에 적합한 대응변수를 활용하여 저수지의 저수율, 용수 부족 및 가뭄 대응능력 뿐만 아니라 사회·환경적, 기상학적 영향을 고려한 평가 항목 선정하였다. 항목별 단위 및 특성을 통합하기 위해 스케일 재조정 (Re-Scaling), Z-Score 등 다양한 방법을 활용하여 표준화를 실시하였으며, AHP (Analytic Hierarchy Process), 엔트로피 분석 등을 통해 항목별 가중치를 산정하였다. 또한 농업가뭄에 긍정적인 영향과 부정적인 영향을 미치는 항목을 구분하여 대응변수를 적용하였다. 이를 바탕으로 농업가뭄 취약성을 평가하여 항목별 등급을 구분하였으며, 전국 167개 시군을 대상으로 농업가뭄 취약지도를 작성하였다. 본 연구의 결과는 시군별 맞춤형 농업가뭄 대응정책의 기초자료 활용 가능하며, 농업가뭄 취약지역/상습가뭄지역에 대한 정보 제공이 가능할 것으로 판단된다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.6
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• pp.93-101
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• 2022

RC Slab bridges in Korea account for more than 70% of the total bridges for more than 20 years of service. As the number of aging structures increases, the importance of safety diagnosis and maintenance of structures increases. For highway bridges, cracks are a main cause of deck deterioration, which is very closely related to the decrease in bridge durability and service life. In addition, the damage rate of expansion joints and bearings accounts for approximately 73% higher than that of major members. Therefore, this study defined damage scenarios combined with devices damages and deck deterioration. The stress distribution and maximum stress on the deck were then evaluated using design vehicle load and daily temperature gradient for single and combined damage scenarios. Furthermore, this study performed damage-spread analysis and predicted condition ratings according to a deck deterioration model generated from the inspection and diagnosis history data of cracks. The heterogeneous damages combined with the member damages of expansion joints and bearings increased the rate of crack area and damage spread, which accelerated the time to reach the condition rating of C. Therefore, damage to bridge members requires proper and prompt repair and replacement, and otherwise it can cause the damage to bridge deck and the spread of the damage.

• Journal of the Korean Society of Marine Environment & Safety
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• v.15 no.4
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• pp.345-354
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• 2009

The review of statements and coastal development characteristics in South Korea were diagnosed by the consultation on the coastal area utilization in Korea. The occupation and the use of public water were dominated by installation of coastal structure and seawater supply and drainage whereas the reclamation areas were predominantly utilized for developing industrial complex, harbor, fishing port and road. The occupation and the use were dominant in western coast, but reclamation was dominant in southern coast of Korea. The number of utilization cases was particularly greater in Jeonnam, Gyeongnam, and Gyeonggi Province including Incheon. The number of the statements reviews increased by more than 200 cases in 2008 compared with 2007, and most of them were the simple statements. The statements related to ocean disposal of dredged sediment, reclamation, dredging sediment, seawater supply and drainage, and marine sand mining were submitted for review. Coastal utilization was especially active in the regions of seawater quality criteria I and II. In particular, special management sea areas designated under the relevant marine regulations were utilized mostly by reclamation for developing harbor, fishing port and coastal structure. Development activities in national parks comprised primarily structure installation and coastal maintenance. In the fisheries resources protection areas, 40% of the total cases accounted for coastal maintenance, 31% for structure installation, and 16% for seawater supply and drainage. In addition, alternative plans for the improvement in policies and system of marine environmental impact assessment were suggested to enhance the function and confidence of the consultation on the coastal area utilization in Korea.

• The Korean Society of Law and Medicine
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• v.23 no.2
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• pp.119-139
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• 2022

Brain stimulation technology that administers electrical and magnetic stimulation to a brain has shown a significant level of possibility for treating a wide range of various neurological and psychiatric disorders. Depending on its nature, the technology is defined either as invasive or non-invasive, and deep brain stimulation (DBS) is one of the most well-known invasive brain stimulation technologies. Currently categorized as grade 4 medical device in accordance with Guideline On Medical Devices And Their Grades, a Notification of Ministry of Food and Drug Safety (MFDS), the DBS has been used as a stable treatment for several diseases. At the same time, the DBS technology has recently achieved substantial advancement, encouraging active discussions for its use from various perspectives. On the contrary, debates over legal regulation related to the use of DBS has relatively been smaller in numbers. In this context, this article aims to 1) introduce the DBS technology and its safety in setting out the tone; 2) touch upon major legal issues that would potentially rise from its use for four different purposes of treatment, clinical study, areas of non-standard treatment where no other methods are available, and enhancement; and finally 3) highlight disputes concerning common emerging issues observed in the aforementioned four purposes from the viewpoint of legal responsibility and liability of using the DBS, which are benefit-risk assessment, physicians' duty of information, patients' capacity to consent, control for device, and insurance coverage.

• Journal of the Society of Disaster Information
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• v.19 no.3
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• pp.673-688
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• 2023

Purpose: Fires that occur during construction are infrequent, but cause great damage. Recently, with the growth of the logistics and distribution industry, the number of construction sites for new logistics warehouses is increasing, so it was selected as a research subject and research was conducted to reduce accidents at construction sites through the development of a fire risk assessment tool to quantitatively approach fire prevention. Method: A comprehensive fire risk assessment tool was accumulated by classifying the work in progress, classifying combustibles and ignition sources by grade, excluding air (oxygen), which is difficult to control, and additionally substituting evacuation safety. Result: Using the developed and proposed fire risk evaluation tool, excavation work with low fire risk, facility construction with medium fire risk, and finishing work with high fire risk were sampled to derive the result (CGI). Conclusion: In this study, it was possible to establish specific preventive measures and evaluate evacuation safety by controlling physical conditions (combustibles) and energy conditions (ignition sources) according to the risk assessment by developing a tool that can evaluate the risk of 14fire occurrence at construction sites. It is expected that in the future, through the application of the fire risk evaluation tool at construction sites, it will be provided as a criterion for establishing a process plan that can reduce risk and evaluating the adaptability of firefighting equipment.14

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2013.04a
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• pp.115-115
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• 2013

최근의 분진폭발은 플라스틱, 의약품, 목재, 곡물 저장고, 고체연료, 화학제품 제조공정 등을 포함하여 성형 및 가공 공정 등에서 화재폭발사고가 발생되고 있다. 폐목재를 재활용하여 PB(Particle board)를 생산하는 국내 제조사업장에서는 화재폭발 사고가 빈번히 발생하고 있어 예방대책이 요구되고 있다. 본 연구에서는 폐목재 제조공정의 사고예방과 목재분진 취급공정에 대한 안전대책 등을 제시하기 위하여 사고원인 물질인 폐목재 부유분진의 폭발특성실험을 실시하고 실험결과를 검토하였다. 또한 폐목재 분진의 화재폭발위험성을 상세히 평가하기 위하여 해당 물질의 자연발화점, 축열저장시험, 및 최소점화에너지 등의 화재폭발위험특성값을 실험적으로 조사하였다. 본 연구에서 사용한 폐목재 시료의 비구형 입자형태를 가지는데 입도분석기의 측정 결과 평균 입경은 $15.96{\mu}m$로 조사되었다. 또한 목재 분진의 함수율은 3.88%이며 중금속함유량은 1.73%이다. 자연발화점 측정결과 $225.5^{\circ}C$로서 비교적 낮게 측정되었고 퇴적분진에 대한 화재의 위험성은 높게 나타났다. 반면에 축열저장시험 결과를 통하여 공정관리 온도 및 보관온도를 $150^{\circ}C$ 이하로 관리하면 축열에 의한 자기분해 위험성은 낮은 것으로 판단되었다. 그러므로 축열에 의한 화재폭발 등의 위험성은 낮은 것으로 사료 된다. 최대폭발압력($P_{max}$)은 8.7 bar이며 폭발하한농도 (LEL)는 $60g/m^3$으로 나타났다. 부유분진의 폭발특성실험 결과 분진폭발지수(Kst)는 폭발등급 St 1 (0$bar{\cdot}m/s$)으로 나타났으며 폭발에 의한 위험성이 약한 분진으로 판정되었다. 최소점화에너지(MIE)는 10mJ < MIE <30mJ의 범위로 측정되었으며, 계산에 의해 추정된 최소점화 에너지(Es) 값은 14 mJ로서 일반적인 발화감도(Normal ignition sensitive)로 분류되었다. 이는 실질적인 점화원만 제거하여도 분진폭발을 예방할 수 있다는 것을 의미한다. 그러나 분진 폭발사고를 예방을 위하여 MIE값이 공정운전온도 $100^{\circ}C$ 초과 시에 급격히 낮아질 수 있으므로 운전 온도 설정에 있어서 주의가 필요하다.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.2
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• pp.393-404
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• 2018

The tunnel can be planned to connect to underground roadway and surface road. The large tunnel and branch section are made when the ramp tunnel access to the main tunnel. In the branch section, stress concentration can be assigned and it can be very important for the stability of the tunnel. This study assessed the behavior of rock pillar in double deck tunnel diverging area by using a two dimensional numerical analysis. This study evaluated different safety factors according to pillar width and the ramp tunnel position in branch. By the assessment of the strength-stress ratio, tunnel pillar width is suggested in order to secure the safety factor 1.5.

• Journal of the Korean Society of Marine Environment & Safety
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• v.19 no.5
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• pp.439-458
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• 2013

Temporal and spatial variations of water quality were investigated in the Cheonsu Bay of Yellow Sea, Korea from 2010 to 2011. Water samples were collected at 16 stations and physicochemical parameters were analyzed including water temperature, salinity, suspended solids (SS), chemical oxygen demand (COD), dissolved oxygen (DO), Chlorophyll a and nutrients. Spatial distribution patterns of all survey items were not clear among stations but the bimonthly variations were distinct except the bottom water of the suspended solids. The trend analysis by principal component analysis (PCA) during 2 years revealed the significant variations in water quality in the study area. Spatial water qualities were discriminated into 3 clusters by PCA; station cluster in the surface water 1, 2~11, and 12~16, the bottom water 1, 2~7, and 8~16. Annual bimonthly water qualities were clearly discriminated into 3 clusters by PCA. But tend of cluster in the surface and bottom water was difference, period most of the research was low in nutrient. Ecology-based water quality criteria was a good level of grade II. Bimonthly results are shown as III grade(normal) at June and August, II grade(good) at October and December and I grade for February and April. Water quality was showed by the input of fresh water same as those of Kyoungin coastal area, Asan coastal area, Gunsan coastal and Mokpo coastal area in the Cheonsu.

• Korean Chemical Engineering Research
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• v.61 no.1
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• pp.80-88
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• 2023

Ensuring safety in the designing of manufacturing and handling facilities for low-density polyethylene (LDPE) is difficult because there are no standards for the dust explosion characteristics of LDPE. In this study, a dust explosion test was performed on two dust samples collected from a bag filter (LDPE 1) during the LDPE manufacturing process and sedimentary dust (LDPE 2) leaked outside a facility such as a silo, and the LDPE 2 explosion test results were summarized. Particle size analysis showed that the volume-based particle diameter (median) was 95.04 ㎛ and the number density was 0-1 ㎛. The maximum explosion pressure (P_max) was 6.6 bar, and the maximum rate of explosion pressure rise was 366 [bar/s] at 1500 g/m³. Accordingly, the dust explosion index (K_st) was 99.4 bar·m/s, which was confirmed as ST-1 grade. Moreover, the minimum ignition energy and minimum ignition temperature was 10 mJ and 450 ℃, respectively. Currently, manufacturing and handling design is based on the characteristic values of high-density polyethylene (HDPE). However, as the test results show that LDPE 2 dust has a higher risk than HDPE (particle diameter 61.6 ㎛), caution is required when using the HDPE design criteria in the LDPE manufacturing process.

• Proceedings of the KIEE Conference
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• 2008.10b
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• pp.540-541
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• 2008

원자력 발전소 격납구조(containment) 내에 설치되는 센서, 구동기(actuator) 및 설비는 원전의 안전운전과 함께 방사능 누출사고와 같은 중대사고(severe accident)를 예방하기 위한 것이다. 격납구조 내부는 Category I 등급으로 분류되며, 격납구조 내부에 설치되는 센서, 구동기, 기기 및 통신망은 IEEE Std. 323-1974에서 정의하는 극한환경(harsh environment) 요건에서 생존할 수 있는 내환경성이 요구된다. 이러한 엄격한 내환경성 요건으로 인해 일반 산업의 IT 기반 센서통신망이 원전 격납건물 내부에는 적용되지 않고 있다. 최근에 이르러 독일을 중심으로 신규로 건설 중이거나 계획 중인 원전에서는 일반 산업의 IT 기반 센서 통신망 적용이 검토되고 있다. 본 논문에서는 IT 기반의 첨단 센서 통신망 기술을 격납구조내부와 같은 극한 환경에 적용하기 위한 방안을 제시하고자 한다. 정상운전중의 원전 격납 건물 내부의 환경(온도, 감마선, 습도) 특성과 중대 사고를 가정한 DBA (설계 기준사고) 요건에서의 환경 특성을 조사하였다. 또한 설계기준사고에서 정의한 감마선 조사 환경에서 통신 시스템의 생존성을 실험하였다. 이를 토대로 격납구조내부의 원전 극한 환경 통신망의 개선방안을 제시하고자 한다.