• 한국환경복원기술학회지
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• 제19권5호
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• pp.29-45
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• 2016

This study identified vulnerable regions in the national parks of the Republic of Korea (ROK). The potential vulnerable regions were defined as areas showing a decline in forest productivity, low resilience, and high sensitivity to climate variations. Those regions were analyzed with a regression model and trend analysis using the Enhanced Vegetation Index (EVI) data obtained from long-term observed Moderate Resolution Imaging Spectroradiometer (MODIS) and gridded meteorological data. Results showed the area with the highest vulnerability was Naejangsan National Park in the southern part of ROK where 32.5% ($26.0km^2$) of the total area was vulnerable. This result will be useful information for future conservation planning of forest ecosystem in ROK under environmental changes, especially climate change.

• Journal of Electrical Engineering and Technology
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• 제13권3호
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• pp.1052-1059
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• 2018

This paper deals with commutation failure of the line-commutated converter high voltage direct current (LCC HVDC) system caused by a three phase fault in the ac power system. An analytic calculation method is proposed to estimate the maximum permissible voltage drop at the LCC HVDC station on various operating point and to assess the area of vulnerability for commutation failure (AOV-CF) in the power system based on the residual phase voltage equation. The concept is extended to multi-infeed HVDC power system as the area of severity for simultaneous commutation failure (AOS-CF). In addition, this paper presents the implementation of a shunt compensator applying to the proposed method. An analysis and simulation have been performed with the IEEE 57 bus sample power system and the Jeju island power system in Korea.

• 지질공학
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• 제10권1호
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• pp.27-38
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• 2000

강원도 흥호리 지역의 수리지질과 지하수의 오염취약성을 평가하였다. 연구지역의 주 대수층은 피압 단열암반 대수층으로 지하수 유동과 재충진이 주로 단열을 통해 이루어진다. 순간수위변화시험, 순간 간섭시험 그리고 양수시험을 통해 얻은 대상 대수층의 평균 투수량계수와 저유계수는 각각 3.2$\times$$10^{-3}$~2.0$\times$$10^{-2}$$m^2$/min, 1.3$\times$$10^{-7}$~9.15$\times$$10^{-4}$이다. 거주지역 상부에 위치한 축산단지의 오수로 인해 단열대의 지하수가 오염되었고 오염지하수가 단열대를 통해 이동함에 따라 하부 주민거주지역의 음용 지하수의 오염취약성을 드러내고 있다.

• 한국기후변화학회지
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• 제3권1호
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• pp.51-69
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• 2012

이 연구는 기후변화가 지자체의 식물, 동물, 보전구역 등 생태계에 미치는 취약성을 현재와 미래 시점에서 시 공간적으로 분석하는 방법론을 논의하고, 적응 능력을 높이기 위한 방안을 토의하였다. 생태계 부문의 취약성 평가는 침엽수를 중심으로 한 수목 생장과 분포의 취약성, 해충과 꿀벌을 중심으로 한 곤충의 취약성, 국립공원을 중심으로 한 보전구역 관리의 취약성으로 수행되었다. 구체화된 각 대용변수의 취약성을 평가하기 위하여 기후노출, 민감도, 적응능력의 대용변수 및 세부 대용변수를 선정하였다. 현재를 기준으로 하였을 때 침엽수의 생장과 분포의 취약성, 해충과 꿀벌의 취약성, 국립공원 관리의 취약성은 기후노출, 민감도, 적응능력 대용변수 가운데 기후노출에 가장 큰 영향을 받는다. 현재로부터 2100년까지 미래로 갈수록 침엽수의 생장과 분포의 취약성, 국립공원관리의 취약성에 대한 지역 간 격차는 커지고, 해충과 꿀벌의 취약성에 대한 지역 격차는 줄어드는 경향을 나타냈다.

• 대한원격탐사학회지
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• 제35권2호
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• pp.217-228
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• 2019

본 연구에서는 9.12 경주지진이 발생한 경주시를 대상으로 AHP와 GIS를 사용하여 지진취약성지도를 작성하고 이를 평가하였다. 지질공학적, 물리적, 사회적, 구조적, 수용적 요인을 주요지표로 선정하였으며, 이와 관련된 18개의 하위지표를 선정하여 공간데이터베이스로 구축하였다. AHP를 사용하여 도출된 가중치는 18개 하위 지표에 적용되었으며, 이를 기반으로 5가지 주요지표의 취약성 지도를 생성하였다. 생성된 5개의 지도에 가중치를 부여한 후, 이를 중첩하여 최종 결과물인 지진취약성지도를 생성하였다. 취약성 지도는 5개의 범주(safe, low, moderate, high, very high)로 분류하였으며, 경주시 전체 면적 중 3%가 아주 높음(very high), 19%가 안전(safe) 지역으로 나타났다. 행정동 기준으로는 중부동, 황오동, 황성동, 성건동, 동천동이 위험지역으로, 보덕동, 강동면, 양북면, 양남면, 외동읍이 안전지역으로 나타났다. 본 연구에서 작성된 지진취약성지도는 사전에 취약지역을 파악함으로써 지진 재해로 인한 피해를 최소화하고, 지진 재해 관련 정책 수립 시 중요한 기초자료로 활용될 수 있을 것으로 판단된다.

• 전기학회논문지
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• 제66권12호
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• pp.1682-1688
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• 2017

In modern society, the number of industrial customers using equipment sensitive particularly to voltage sags is rapidly increasing. As voltage sags can cause loss of information as well as false operation of the control device, it results in the vast economic damage in industrial processes. One way to mitigate voltage sags in the sensitive loads is the installation of distributed generation (DGs) on the periphery of these loads. In addition, renewable energy sources are currently in the spot light as the potential solution for the energy crisis and environmental issues. In particular, wind power generation which is connected to a grid is rising rapidly because it is energy efficient and also economically feasible compared to other renewable energy sources. On the basis of the above information, in this paper, with Wind Turbine Generators (WTGs) installed nearby the sensitive load, the analysis of the mitigating effect comparison by types of WTGs is performed using voltage sag assessment on the IEEE-30 bus test system. That is, the areas of vulnerability according to types of WTGs are expected to be different by how much reactive power is produced or consumed as WTG reactive power capability is related to the types of WTGs. Using the concept of 'Vulnerable area' with the failure rate for buses and lines, the annual number of voltage sags at the sensitive load with the installation of WTGs per type is studied. This research will be anticipated to be useful data when determining the interconnection of wind power generation in the power system with the consideration of voltage sags.

• 한국측량학회지
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• 제38권4호
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• pp.295-304
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• 2020

IPCC는 기상이변의 예방 대책의 중요성을 권고하였으며 폭염은 주요 예방대책수립 주제 중 하나이다. 일반적으로 예방대책수립을 위한 기존 연구는 지형적 특성과 사회적 특성을 따로 구분하여 폭염취약지역을 도출하였으나 본 연구에서는 공간, 지형적 특성뿐만 아니라 사회적 특성을 함께 고려하여 폭염취약지역을 분석하고자 하였다. 에너지 사용량, 인구밀도, 정규식생지수, 수변이격거리, 태양복사량, 도로분포를 변수로 하여 점검하고, 여러 회귀모형 중 가장 적합한 모형인 Spatial Lag Model을 선택하여 사용가능한 변수를 추출하였다. 그리고 Fuzzy 이론에 기초하여 각 변수에 대한 폭염 취약정도를 분석하고, 6개의 변수를 중첩분석하여 최종적으로 폭염취약지역을 도출하였다. 연구 대상지는 폭염의 영향이 큰 대구광역시를 선정하였으며, 취약지역의 경우 기존 도심지이며 수변 및 식생에 영향을 적게 받은 대구 서구, 남구, 달서구에 주로 분포되어있음을 확인하였다. 이를 통해 대구광역시의 폭염 저감을 위한 정책적 지원에 있어 공간적, 사회적 특성을 모두 고려해야 함을 확인하였다.

• 농촌계획
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• 제21권2호
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• pp.127-135
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• 2015

In recent years, meteorological disasters have frequently occurred in rural areas. As a result, there have been growing concerns over the protective measures needed. In order to avoid natural risks and damage, and to strengthen countermeasure to meteorological disasters, local governments needs to be prepared. Therefore, this paper seeks to prevent meteorological disasters through mapping of inundation vulnerability in agricultural land, Chungcheongnam-do. In doing so, this study were considered 5 variables (i.e. precipitation, region of altitude below 50m, region of slope gradient is below 10 degree, distance from river within less 50m) for creating vulnerability map. The precipitation was excluded in five variables. Since, the precipitation which include Daily maximum precipitation, 2-Daily maximum precipitation, summer precipitation was not any correlation among them. The results of analysing four variables, exclusive of precipitation, were showed that the agricultural lands where located in Dangjin, Buyeo, Hongseong and Asan were low correlation of inundation vulnerability by overlapping analysis. Moreover, The correlation analysis was showed low correlation between each factors and the annual average area of agricultural lands' inundation, whereas, the correlation analysis which was overlapping each factor showed high correlation. In conclusion, in order to create reliable vulnerability map in agricultural lands, Chungcheongnam-do, it must be considered to overlap analysis of the four main factors such region of altitude below 50m, region of slope gradient is below 10 degree, distance from river within less 50m. We suppose that this study's analysis can help to set the preparedness site of agricultural lands inundation.

• Structural Engineering and Mechanics
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• 제78권3호
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• pp.351-368
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• 2021

This paper, by applying a reliability-based framework, develops seismic vulnerability macrozonation maps for Tehran, the capital and one of the most earthquake-vulnerable city of Iran. Seismic performance assessment of 3-, 4- and 5-story steel moment resisting frames (SMRFs), designed according to ASCE/SEI 41-17 and Iranian Code of Practice for Seismic Resistant Design of Buildings (2800 Standard), is investigated in terms of overall maximum inter-story drift ratio (MIDR) and unit repair cost ratio which is hereafter known as "damage ratio". To this end, Tehran city is first meshed into a network of 66 points to numerically locate low- to mid-rise SMRFs. Active faults around Tehran are next modeled explicitly. Two different combination of faults, based on available seismological data, are then developed to explore the impact of choosing a proper seismic scenario. In addition, soil effect is exclusively addressed. After building analytical models, reliability methods in combination with structure-specific probabilistic models are applied to predict demand and damage ratio of structures in a cost-effective paradigm. Due to capability of proposed methodology incorporating both aleatory and epistemic uncertainties explicitly, this framework which is centered on the regional demand and damage ratio estimation via structure-specific characteristics can efficiently pave the way for decision makers to find the most vulnerable area in a regional scale. This technical basis can also be adapted to any other structures which the demand and/or damage ratio prediction models are developed.

• 환경영향평가
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• 제22권6호
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• pp.677-693
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• 2013

IPCC showed that calculation of climate vulnerability index requires standardization process of various proxy variables for the estimation of climate exposure, sensitivity, and adaptive capacity. In this study, four different methodologies of standardization methods: Z-score, Rescaling, Ranking, and Distance to the reference country, are employed to evaluate climate vulnerability-VRI (Vulnerability-Resilience Indicator) over Korean peninsula, and the error ranges of VRI, arising from employing the different standardization are estimated. All of proxy variables are provided by CCGIS (Climate Change adaptation toolkit based on GIS) which hosts information on both past and current socio-economic data and climate and environmental IPCC SRES (A2, B1, A1B, A1T, A1FI, and A1 scenarios) climate data for the decades of 2000s, 2020s, 2050s, and 2100s. The results showed that Z-score and Rescaling methods showed statistically undistinguishable results with minor differences of spatial distribution, while Ranking and Distance to the reference country methods showed some possibility to lead the different ranking of VRI among South Korean provinces, depending on the local characteristics and reference province. The resultant VRIs calculated from different standardization methods showed Cronbach's alpha of more than 0.84, indicating that all of different methodologies were overall consistent. Similar horizontal distributions were shown with the same trends: VRI increases as province is close to the coastal region and/or it close toward lower latitude, and decreases as it is close to urbanization area. Other characteristics of the four different standardization are discussed in this study.