• Journal of the Economic Geographical Society of Korea
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• v.9 no.2
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• pp.149-166
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• 2006

The purpose of this study is to produce time-distance cartograms based on the various Korean transportation networks, and to analyze the spatial structure of time-distance accessibilities. For the purpose this study attempts to develop continuous area cartogram by utilizing Wolf's algorithm for creating contiguous cartogram in ArcGIS 9. The absolute physical space was transformed to the functional space indexed by time-distances along various transportation networks in Korea. We examined the differences in the time-distance accessibilities among transportation networks. This study makes a comparison between the spatial structure of time-distance accessibility of KTX network with them of existing railroad network, as well as with them of road network. In order to clarify the spatial structures of time-distance accessibilities, we restructured them on the time-distance circular diagrams and performing Multi-Dimensional Scaling analysis. Overall structure of time-distance accessibilities shows similar patterns: The time distances are shrinked a lot along the Seoul-Busan axis, while coastal parts, in particular the eastern part of the county, are shrinked relatively little via all transportation networks. The Road network affects significantly on the accessibilities of cities in Gangwon-do and Gyeonggi-do, while railway network affects on the accessibilities of cities in Jeolla-do and Gyeongsang-do in general. When we compared the time-distance accessibilities based on the 5 largest cities, Seoul appears as the most accessible city from/to all other cities in Korea. We can also find significant changes in the time-distance accessibility between KTX network and existing railroad network. Cities along the KTX network, in particular cities which has KTX stops, improved significantly in time-distance accessibilities.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.2
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• pp.113-121
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• 2021

The occurrence mechanisms of heatwave have been conventionally studied at a synoptic scale. However, the implications of precedent droughts on the following up heatwave occurrences have not been elucidated and are important to address the complex causal mechanisms of heatwaves. Therefore, this study evaluated the causality and implication of the seasonally antecedent droughts to summer heatwaves that occurred for 46 years since 1974 using partial least squares-structural equation modeling (PLS-SEM). The resulting contribution of winter (spring and summer) droughts to summer heatwaves for Seoul-Gyeonggi, Gangwon, and Chungcheong provinces were 37 % (29 % and 22 %), 21 % (18 % and 29 %), and 17 % (8 % and 38 %), respectively. This is due to the regional variability of seasonal drought impacts. Furthermore, Gangwon and Chungcheong provinces, which have a higher level of impacts of summer droughts to summer heatwaves, are more likely to be exposed to the compound drought-heatwave damages compared to Seoul-Gyeonggi province, which has relatively a low-level impact of summer drought.

• Proceedings of the Korean Society of Computer Information Conference
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• 2018.07a
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• pp.279-280
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• 2018

본 과제는 비행체에 자동제어 시스템인 자동항법비행기능을 탑재한 무인기를 제작한다. 자동항법비행이 가능한 무인기는 사람이 직접 조종하는 기존의 비행체들 보다 정밀하고 섬세한 제어가 가능하며 조종자의 시야가 닿지 않는 곳에서의 비행이 가능하다는 장점을 가진다. 또한 상공에서 영상을 촬영하며 5.8GHz대역의 영상 송 수신기를 통한 실시간 영상 확인이 가능하다. 본 과제는 GPS를 이용한 프로그래밍을 통해 미리 지정한 좌표를 따라 비행이 가능하며 실시간 영상 수신이 가능하기 때문에 사람이 직접 갈 수 없는 오염된 지역 등의 정찰이 가능하고, 비행체에 장착되는 장비에 따라 군용, 소방용 등의 다양한 범위에서의 활용이 가능할 것으로 예상된다.

• 한국지구과학회:학술대회논문집
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• 2010.04a
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• pp.137-137
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• 2010

해양 혼합층은 해양-대기 간의 상호작용을 통해서 기후 변화 뿐만 아니라, 식물성 플랑크톤 분포와 같은 생물학적 측면에도 큰 영향을 줄 수 있기 때문에 매우 중요하다. 따라서 본 연구에서는 우리나라 장단기 기후변동에 많은 영향을 주는 북동아시아 근해 내에서의 혼합층 깊이의 시공간 변동을 분석하였다. 기존에 해양 관측 자료가 절대적으로 부족했던 점을 극복하기 위해 2000년부터 전구 해양에서 실시간으로 수집되기 시작한 해양중층부이(ARGO) 자료를 활용하였다. 지금까지 제시되어 온 다양한 해양 혼합층 결정 기준 중 가장 널리 사용되고 있는 Levitus et al.(1997)의 기준을 적용하여 북동아시아 근해의 혼합층 깊이를 산출하였으며, 그 변화를 위도, 경도, 해안으로부터의 거리, 계절 등에 따라 분석하였다. 또한 계절적 변화에서 겨울철 해양 혼합층 변화의 역전이 나타나는 지역을 분석하였다. 이와 같은 분석결과는 추후 해양 혼합층 깊이 결정 방법에 대한 연구의 기초자료로 활용될 것으로 기대한다.

• Journal of Korean Society of Transportation
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• v.23 no.7 s.85
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• pp.87-98
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• 2005

Through rail transit has many merits as a safe, environmental harmonic and scheduled transit, there are many problems to construct railroads because of the public resentment. However, there is no reasonable way to settle the conflict properly and it causes enormous social and economic losses. This paper suggests a methodology to evaluate public complaint using the AHP technique, which is generally used as the methodology to evaluate public complaint using the AHP technique, which is generally used as the Multi-Criteria Decision Making (MCDM). However, the result from the AHP has some defects to control conflicts because the interests related to railroad projects are so complex that it is hard to make people persuaded easily. Therefore, this paper suggests 'the improvement ranking method', 'the sensitive analysis', and 'the assessment of independence relationship' which can aid the basic AHP to be robust. And the AHP. modified by fuzzy method, is also suggested to apply this methodology to example rail paths in Korea.

• Journal of Distribution Science
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• v.4 no.1
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• pp.53-78
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• 2006

We call this world network society. Logistics is one of important network systems which connect people, materials and information. The World Economy Conditions of 21st Century has been Changed so rapidly. These Changes are more conspicuous in Northeast Asia than other Regions. China, North Korea and Russia have reformed their Economical and Social Systems, which enlarged the Trade Volume and Traffic Demand in this Area and between Europe. The Railway System Crossing the Eurasia Continent, such as TSR(Trans Siberian Railway), TCR(Trans China Railway), TMR(Trans Manchuria Railway), TMGR(Trans Mongolia Railway) and TKR(Trans Korea Railway), have been becoming very important to enhance the International Transportation efficiency and to connect each continents by International Railways. This Paper investigated and surveyed the logistical Environments surrounding this Korea Peninsula. And concerned with the Crossing Continents Railway, TSR,TCR(TMR, TMGR), TKR, operating Conditions and Tasks that must be considered and solved were also investigated. Especially the Current Logistical Conditions of China, Russia, and North Korea and their Problems were surveyed. And the SWOT of these Railways were analyzed and compared. The Visions and Goals of these Inter-Continental Railways were suggested in terms of their Rationalization of Operations and efficient Connections among many Countries. Not only the Policies and Strategies/Tactics which should be considered but also and Many detail countermeasures which should be introduced and adopted were suggested.

• Journal of the Korean Society for Railway
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• v.13 no.2
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• pp.236-243
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• 2010

We examine the change in healthcare utilization pattern of cancer patients since the launch of KTX in 2004. It is found that during the year of 2004 and 2005 the rapid increase in the ratio of cancer patients' healthcare utilizations for the tertiary hospitals in Seoul to the total healthcare utilizations has accompanied the rapid decrease in the corresponding ratio for the tertiary hospitals in the local metropolitan areas under the influence of KTX while the corresponding ratio for the tertiary hospitals in the local cities with little influence of KTX on them has exhibited mild change. Since healthcare consumers' choice of hospitals can be characterized by "foot voting" action in the healthcare service market in Korea, such a phenomenon may have strong implication that the introduction of KTX may have affected substantially the inter-area healthcare utilization pattern by cancer patients by reducing various sorts of long-distance travel costs. Therefore, considering the potential contribution of KTX to the increase of cancer patients' accessibility to hospitals with higher qualities, support policies such as fare discount for low-income cancer patients in local areas may need to be taken into consideration where the well-designed fare discount program for low-income cancer patients may increase utilizations of KTX by lowincome cancer patients without incurring additional costs to running of KTX.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.1058-1062
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• 2008

지구 온난화에 의한 대기 순환의 변화와 이에 따른 수증기 수송 및 강수량의 변화는 전지구 및 지역적인 수문환경의 변화를 초래하므로 장기적인 차원의 수자원 계획 수립에는 반드시 기후 변화에 따른 영향이 제대로 반영되어야 한다. 그러나 개별 모델이 사용하는 역학과정과 물리과정의 모수화 및 분해능이 다르고 이에 따른 모의 결과도 다르게 나타나는 등의 상당한 불확실성이 내재되어 있다. 따라서 본 연구에서는 기후변화에 관한 정부간 패널인 IPCC(Intergovernmental Panel on Climate Change)에 참여한 대기해양결합 대순환모델(AOGCMs)이 온실가스 배출 시나리오를 바탕으로 생산한 기온과 강수의 불확실성을 동아시아에 대해 평가하고 이를 바탕으로 미래 기후를 전망하였다. 국립기상연구소 ECHO-G/S 모델과 IPCC 23개 모델의 배출 시나리오(Special Report on Emissions Scenarios, SRES) 자료는 20세기(1900-1999년)와 21세기(2000-2099년)의 200년 동안이고, 관측자료는 영국 CRU(Climate Research Unit) 월평균 2m 기온의 30년(1961-1990년) 평균값과 CMAP 월 평균 강수량의 21년간(1979-1990년) 평균값을 이용하였다. 동아시아지역 기온과 강수의 불확실성을 평가하기 위해서 모델과 관측간 편이, 평균제곱근오차(RMSE) 등의 통계적인 방법을 사용하였다. 동아시아 지역의 연평균 기온은 대체로 모델의 기온이 관측보다 적게 모의되는 음의 편이를 나타내고, 강수는 모델이 관측보다 더 크게 모의 되는 양의 편이를 나타냈다. 계절적으로는 여름철 강수와 봄철 기온의 편이가 크게 나타났다. 연평균 및 겨울철 강수와 기온의 RMSE는 비례하는데 이는 기온 모의성능이 좋은 모델이 강수 모의성능도 좋게 나타나는 것을 의미한다.

• Journal of Korean Society of Transportation
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• v.30 no.6
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• pp.59-70
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• 2012

The relative importance of leisure trip has been increased after adopting the five-day workweek system and considering the higher income level. Thus, the value of travel time for intercity leisure trips should be estimated to conduct a reasonable benefit/cost analysis for railway construction projects. In this paper, the value of travel time was estimated separately for each trip purpose such as business, leisure, and other non-business than leisure. The estimated values of leisure travel time ranged from 5,310 to 14,185 (won/hr) by altering travel mode, and were increased by 42-107% when comparing with those of non-business travel time. Besides, how to apply the value of intercity leisure travel time for B/C analysis of railway projects was suggested. For the construction case of a railway connecting Chuncheon and Sokcho, the estimated benefit was increased by 2.3%.

• Korean Security Journal
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• no.49
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• pp.157-183
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• 2016

Countries across the globe, including those in Europe, are waging a "war against terrorism" as international terrorist groups such as ISIS and lone-wolf terrorists have unleashed various large-scale attacks on rail infrastructure. Anti-South Korean sentiment exists in Muslim-majority countries because the nation has cooperated with the US for its military interventions in the Middle East, and ISIS has threatened to target South Korea four times since September 9, 2015. In addition, North Korea has been left isolated in the international community with its missile and nuclear tests, while further escalating inter-Korean tension and threatening to strike major facilities and attack important figures in the South. These situations imply that South Korea is no longer immune to terrorist attacks. If the nation fails to prevent or deter such terrorist attacks against rail networks, massive casualties, property damage and social confusion would be unavoidable, deteriorating national and international trust in its counter-terrorism policies. This may lead to a national crisis involving decreases in the number of tourists, dampened interest of foreign investors, and capital flight. This study aims to propose policy measures to enhance railroad security checks, based on the work of railroad police officers, for the sake of protecting citizens and public safety. The suggestions include an incremental expansion of railroad security checks; growth of the railroad police force and adjustment of their policing distribution with other police officers; enhancement of security systems across important rail networks; improvement of the Railroad Safety Act; Southeast Asia, including the corresponding strengthening of the national crackdown illegal immigrants, and plans for pre-emptive and regular cooperation among organizations related to the promotion of security checks and the prevention of terrorist attacks.