• International Journal of Highway Engineering
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• v.9 no.4
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• pp.83-92
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• 2007

In 2004, the number of traffic crashes and deaths in Korea are 220,755 and 6,563, respectively. Korea Road Traffic Safety Authority reported that the number of traffic accidents occupies over 25% out of total accidents, and found that traffic crash probability is extremely high at intersections since intersections have various traffic conflict points. A Safety study using Traffic Conflict Technique is much more useful than a study using reported traffic accident data. Existing traffic conflict research hardly considered conflict severity occurring at intersections. So, the study developed new criteria considering conflict severity. Analytic methods precisely detecting crashing points using field surveying data, and applied an application of our new criteria. Opposing left-turn conflict criteria was devided by three groups(high severe conflict, middle severe conflict, and less severe conflict) based on conflict boundary by means of a standard vehicle length. After analyzing field surveying data(3hours), we found totally 41 opposing left-turn conflicts. 3 cases are high severe conflict, and another 10 cases are middle severe conflicts, and the other cases are less severe. Studies related in conflict severity are considerably important to evaluate intersection's detailed safety index, and existing studies(purely conflict counting does not consider severity) have a limitation to clearly determine the level of safety of intersections for an application.

• Journal of Korean Society of Transportation
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• v.17 no.4
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• pp.9-17
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• 1999

교통문제는 과거에 비하여 보다 복잡해지고 다양해지고 있으며, 이러한 교통문제를 해결하기 위한 방안을 도출하는 분석기법 또한 다양해지고 있다. 이러한 기법중 안전도 평가기법에 관한 연구는 선진국에서는 1970년대부터 진행되어 왔으나, 이에 반하여 국내에서는 최근에서야 안전도에 대한 문제가 부각되면서 이에 대한 연구가 시작되고 있는 실정이다. 본 논문은 국내 외 연구사례를 중심으로 교통상충기법(TCT)을 소개하였고, 가장 진보된 방법인 스웨덴의 상충분석기법을 기반으로 국내에 적용할 수 있도록 모형을 개발하고 심각한 정도에 따라 4개 죤으로 분류하여 위험순위를 평가할 수 있는 방법을 제시하였으며, 실제로 이러한 상충분석기법을 국내의 3개 교차로 분석에 적용하여 보았다. 사고와 상충간의 conversion factor는 수집된 자료의 부족으로 사고자료의 심각도까지는 고려하지 못하였으 나, TA값을 구하고 4개죤 분류를 통하여 위험순위를 분석하여 교차로의 안전도평가에 이용할 수 있음은 보여주었다. 상충조사 분석은 안전도 평가를 저 비용과 짧은 시간내에 보다 상세한 결과를 도출할 수 있다는 점과 대상지의 사전 후 단기간 평가 방법에 가장 효과적인 기법이라는 측면에서 국내 안전도 평가에 많이 적용되기를 바란다.

• Journal of Korean Society of Transportation
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• v.26 no.4
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• pp.173-184
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• 2008

Development of an accident estimation model based on accident data can be made after accident occurrences. However, the taking of historical accident data is not easy, and there have been differences between real accident data and police-reported accident data. Also, another difficult shortcoming is that historical traffic accident data better consider driver behavior or intersection characteristics. A new method needs to be developed that can predict accident occurrences for traffic safety improvement in black spots. Traffic conflict decision techniques can acquire and analyze data in time and space, requiring less data collection through investigation. However, there are shortcomings: as existing traffic conflict techniques do not operate automatically, the analyst's opinion could easily affect the study results. Also, existing methods do not consider the severity of traffic conflicts. In this study, the authors presented traffic conflict decision criteria which consider conflict severity, including opposing left turn traffic conflict and cross traffic conflict decision criteria. In order to test these criteria, the authors acquired three signalized intersection images (two intersections in Sungnam city and one intersection in Paju) and analyzed the acquired images using image processing techniques based on individual vehicle tracking technology. Within the analyzed images, level 1 conflicts occurred 343 times over three intersections. Some of these traffic conflicts resulted in level 3 conflict situations. Level 3 traffic conflicts occurred 25 times. From the study results, the authors found that traffic conflict decision techniques can be an alternative to evaluate traffic safety in black spots.

• 한국ITS학회:학술대회논문집
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• 2010.05a
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• pp.163-167
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• 2010

• Journal of Korean Society of Transportation
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• v.22 no.3 s.74
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• pp.127-135
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• 2004

교차로 안전성 진단과 관련된 기존의 연구는 교차로 상에서 발생한 사고 자료에 기초하여 교차로 기하구조 요소, 교통량 및 신호운영방법 등과 관련된 요인을 변수로 사용하여 교통사고건수 예측모형 개발에 관한 연구가 대부분이다. 그러나, 분석하고자 하는 대상 교차로의 사고건수 예측모형을 개발하기 위해 필요한 교통사고 자료의 경우 단 기일에 걸쳐 획득되지 않으며 몇 년간의 사고 자료를 요구할 수도 있다. 이러한 자료를 이용하더라도 사고 발생 기간동안 교차로 사고에 영향을 미치는 요인(교차로 운영방법, 기하구조 등)이 변화될 수도 있다는 문제점을 지닌다. 이와 같은 이유로 교차로 안전성을 진단하는데 있어 기존 교통사고 자료는 언제나 절대적인 자료가 될 수 없다. 이에 대한 보완책으로, 3일에서 5일정도의 조사 자료만으로도 안전성 진단이 가능한 상충자료를 이용하여 교차로 안전성 진단을 할 수 있다. 본 연구는 기존사고 자료를 이용하여 사고 발생에 기인하는 여러 변수들을 교통사고심각도와의 상관관계를 분석하고, 상관관계가 높은 변수를 이용하여 신경망 사고심각도 예측모형을 개발하였으며, 모형 검증을 위해 다중회귀사고심각도 예측모형을 개발하여 비교 평가한 결과 신경망 사고심각도 예측모형의 예측력이 우수한 것으로 나타났다. 현장에서 조사된 상충자료를 신경망 사고심각도 예측모형에 적용하여 상충이 사고로 연결 될 경우 사고심각도를 예측하였으며, 예측된 사고심각도에 가중치를 부여하여 대상 교차로 위험우선순위를 결정한 결과 사고비용에 기초한 위험우선순위 결정법과 같은 순위의 결과를 도출하였다.

• Journal of Korean Society of Transportation
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• v.34 no.1
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• pp.68-80
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• 2016

Interest in freeway truck traffic has increased largely due to greater safety concerns regarding truck-related crashes. The negative interactions between slow-moving trucks and other vehicles are a primary cause of hazardous conditions, which lead to crashes with larger speed variations. To improve operational efficiency and safety, providing a climbing lane that separates slow-moving trucks from higher performance vehicles is frequently considered when upgrading geometrics. This study developed an operations strategy for freeway climbing lanes based on traffic conditions in real time. To consider traffic safety when designing a dynamic strategy to determine whether a climbing lane is closed or open, various factors, including the level of service (LOS) and the percentage of trucks, are investigated through microscopic simulations. A microscopic traffic simulator, VISSIM, was used to simulate freeway traffic streams and collect vehicle-maneuvering data. Additionally, an external application program interface, VISSIM's COM-interface, was used to implement the proposed climbing lane operations strategies. Surrogate safety measures (SSM), including the frequency of rear-end conflicts and, were used to quantitatively evaluate the traffic safety using an analysis of individual vehicle trajectories obtained from VISSIM simulations with various operations scenarios. It is expected that the proposed algorithm can be the backbone for operating the climbing lane in real time for safer traffic management.

• Journal of Veterinary Clinics
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• v.31 no.5
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• pp.412-416
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• 2014

A 7-year-old intact male Pitbull terrier dog was presented with complaints of marked abdominal distension and severe exercise intolerance. Diagnostic studies found a right-sided cardiomegaly with marked dilation of pulmonary arteries, diffuse interstitial pulmonary infiltration and heavy worm burden in the right atrium and ventricle. Color and spectral Doppler echocardiography also revealed tricuspid and pulmonic regurgitation indicating severe pulmonary hypertension. The 104 heartworms were removed by interventional extraction using a loop snare (Snare, Boston Scientific, USA) through external jugular vein. After heartworm removals, the clinical condition of this dog was remarkably improved. To author's best knowledge, this is the first case of interventional heartworm extraction using a loop snare in Korea.

• Journal of Korean Society of Transportation
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• v.20 no.7
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• pp.23-29
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• 2002

Five and more leg intersections have been still in operation in many urban areas. The number of conflicts in five leg intersection is more than four leg intersection. The signal timing design in the five leg intersection should be performed not only to reduce delay but also to increase safety. This paper suggests safety enhanced signal phase sequence design of a rotary with five leg intersection such as phase sequence minimizing the number of conflict points at the rotary with five leg intersections and the phase-length-design procedure by utilizing the Traffic Network Study Tool(TRANSYT). Field data was collected from Gonguptap five leg intersection in Ulsan and TRANSYT-7F was applied for signal timing design model. Optimal signal phase length and sequence of TRANSYT-7F is rearranged based on the Principal of "two moving traffic flows per phase". In conclusion, proposed signal phase design increased delay by 6.2% compared with the optimal signal phase of TRANSYT-7F. However, it could decrease the number of conflict in the five leg intersection by 61.5%.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.26_27
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• 2009

본 논문은 계통의 광역정전을 야기할 수 있는 765kV 루트 고장에 대한 최적 부하차단 위치 및 용량산정 방안을 제안한다. 계통운영은 경제성 및 안정성을 모두 확보하여 운영되어야 하지만 이는 서로 상충되는 요소로서 적절한 운전점이 결정되어야 한다. 이를 위하여 융통 전력을 최대한 운용할 수 있는 융통한계를 결정하여 운영되어야 하며 계통이 융통한계로 운영될 때 이보다 심각한 선로고장(765kV 루트고장)에 대해서는 부하차단이 적용되어야 한다. 이때 차단되는 부하를 최소로 하여 계통을 안정화하는 방안이 필요하며 이를 위하여 본 논문에서는 융통전력 한계를 고려한 최적 부하차단 용량 및 위치선정 알고리즘을 제안한다.

• KDI Journal of Economic Policy
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• v.23 no.1_2
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• pp.5-70
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• 2001

The often raised arguments against allowing Chaebol's ownership of banks, that is, 1) the banks may virtually be transformed into private cash vaults of owners, and 2) conflicts of interests may develop and be possibly abused by chaebols, do not hold under ordinary free market circumstances. Only under some special circumstances in which government imposes artificial regulations on banks such as interest rate ceilings, or provides preferential protection like guaranteeing bank's liabilities, the aforementioned worries can be materialized.