• Journal of Korean Society of Transportation
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• v.24 no.4 s.90
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• pp.129-148
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• 2006

The objective of this thesis is to develop a capacity analysis and to develop a methodology to evaluate Level of Service over the entire freeway sections by single MOE (Measure of Effectiveness) This study set forth from a following viewpoint. to analyze entire freeway sections as freeway facility system, it is important to identify the exact point where congestion would occur and the extent of the congestion. Therefore, in this thesis, congestion mechanism on freeways was figured out and congestion analysis methodology was developed. Thereby maximum possible throughput rate and maximum throughput rate in bottleneck sections were calculated and a congestion analysis was carried out. The difference between the new method and existing Procedures is that maximum possible throughput rate and maximum throughput rate. that can be considered as capacities of un-congested and congested flow in the bottleneck section, are variable capacities dependent on demand flow.

• Proceedings of the Korea Water Resources Association Conference
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• 2023.05a
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• pp.518-518
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• 2023

자연하천에서 오염물질의 혼합 거동은 비균일한 지형학적 요인으로 인해 매우 복잡한 특성을 나타낸다. 일반적으로 오염물질 거동 모델링에서는 수체에서의 혼합을 Fick의 법칙에 따라 유속에 의한 이송과 난류에 의한 확산으로 계산하고, 국부적인 정체현상 등에 의한 non-Fickian 혼합을 야기하는 하천의 특성을 기하학적 지형 형상으로 구현하여 실제 현상에 근접한 혼합 거동을 재현한다. 하지만 계산의 효율성을 위하여 모델링의 차원을 낮추는 경우, 하천의 지형을 경계조건으로 고려할 수 없게 된다. 특히, 1차원 모델링의 경우 하천의 비균일성을 무시하고 1개의 유선으로 간주하며, 이 경우 non-Fickian 물질이동 해석을 위한 추가적인 현상학적 해석이 필요하다. 지난 50년간, non-Fickian 물질이동 해석을 위한 다양한 현상학적 모형이 제시되어 왔다. 하천을 흐름영역과 정체영역으로 구분하고 두 개의 영역 사이의 물질교환 속도를 모델링하거나, Random walk 개념으로 물질이 이동하는 경우와 이동하지 않는 경우를 확률론적으로 모델링하거나, 물질이 정체되었을 때 다시 빠져나오는 시간을 모델링하는 경우가 그 예이다. 본 연구에서는 선행연구에서 제시한 음함수 형태의 현상학적 모형을 기반으로, 수치적 반복계산 없이 상류 경계에서 임의의 형태의 농도곡선(shape-free breakthrough curve)을 갖는 오염물질운(cloud)이 일정 거리를 유하하며 발생하는 변화를 예측할 수 있는 해를 제시한다. 본 연구의 방법론은 추적법(routing procedure)을 활용한 Fickian 혼합 해석, 전달함수(transfer function) 형태의 정체시간분포 해석, 그리고 라플라스 도메인에서의 해석해 유도를 포함한다. 본 연구에서 제시된 해는 2020년 경상북도 김천시에 위치한 감천의 4.5 km 구간에서 수행한 추적자 실험의 현장 자료를 통해 정확도를 검증하여 타당성을 입증하였다.

• Journal of Korean Society of Transportation
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• v.24 no.7 s.93
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• pp.115-128
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• 2006

The analytic methodology of a merging area in KHCM(2004) supposes that congestion nay occur when traffic demand is more than capacity However, in many cases, congestion on merging area occurs when summation of traffic demand of main line and ramp is less than capacity, and in present methodology analysis of how main line and ramp flow effect on congestion occurrence is difficult. In this study, the model that is able to estimate traffic flow condition on merging area in accordance with the combination of main line and ramp demand flow is developed. Main characteristic of the model is estimation of maximum possible throughput rate and maximum throughput rate according to the combination of main line and ramp demand flow. Through the estimation of maximum possible throughput rate and maximum throughput rate. it was Possible to predict whether congestion would occur or not and how much maximum throughput rate and congestion would be on merging area. On one hand, in present LOS evaluation methodology on merging area, congestion state is determined as un-congested flow if demand flow is less than capacity. Therefore, to establish more reasonable In evaluation method, new criterion of LOS evaluation on merging area was searched based on the model of this study.

• Journal of Korean Society of Transportation
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• v.25 no.6
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• pp.99-109
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• 2007

There have been few studies on the impacts of independent recurrent and non-recurrent congestion on freeway networks. The main reason is due partly to the lack of traffic data collected during those periods of recurrent and non-recurrent congestion and partly to the difficulty of using the simulation tools effectively. This study has suggested a methodology to analyze the independent impacts of the recurrent and non-recurrent congestion on target freeway segments. The proposed methodology is based on an elaborately calibrated simulation analysis, using real traffic data obtained during the recurrent and non-recurrent congestion periods. This paper has also summarized the evaluation results from the field tests of two ITS technologies, which were developed to provide drivers with real-time traffic information under traffic congestion. As a result, their accuracy may not be guaranteed during the transition periods such as the non-recurrent congestion. In summary, this study has been focused on the importance of non-recurrent congestion compared to recurrent congestion, and the proposed methodology is expected to provide a basic foundation for prioritizing limited government investments for improving freeway network performance degraded by recurrent or non-recurrent congestion.

• Information and Communications Magazine
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• v.25 no.11
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• pp.7-13
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• 2008

IT'와 '융합'은 최근 사회, 경제, 문화 전반에서 가장 빈번하게 접하는 단어가 되었다. 21세기를 여는 핵심 요소였던 IT는 성장 정체와 위기론을 거쳐 새로운 영역을 창출할 것으로 기대되고 있다. 본고에서는 다양한 모습으로 태동하고 있는 IT기반 융합산업에 의미를 부여하고 그 정책방향을 제시하고자 한다.

• Journal of Korean Society of Transportation
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• v.19 no.6
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• pp.105-118
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• 2001

Incident detection rate and false alarm rate are the key measures tot estimating the performance of automatic incident detection algorithms. It is, however inherently very difficult to improve the two measures simultaneously. The main purpose of this study is to present some methods for solving the problem. For this, an incident detection algorithm has been designed in this study. The algorithm is consisted of two functions, one for detecting incident and another for detecting congestion. A logic for distinguishing non-recurrent congestion from recurrent congestion was employed in the algorithm. The new algorithm basically requires speed, flow, and occupancy data for defining incident situation, but the algorithm is able to perform this task without one of the three parameters. The performance of the algorithm has been evaluated by using the field data collected from Interstate Highway 880 in Bay Area, California. The empirical analysis results are very promising and thus, the algorithm proposed may be very useful for the analysts. This paper presents some empirical test results for the performance of California incident detection algorithm, only for the reference purpose.

• Clinical and Experimental Pediatrics
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• v.49 no.10
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• pp.1067-1072
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• 2006

Purpose : The purpose of this study was to examine the clinical courses and long-term outcomes of children with Allagille syndrome in Korea, and to evaluate the prognostic potentials of identified variables. Methods : We reviewed the clinical manifestations and outcomes of 30 children with Alagille syndrome, investigated from 1984 to 2006 until the end of this study (defined as death or last visit; mean follow-up : 5 years). Results : Cholestasis occurred in 100 percent, cardiovascular abnormalities in 83.3 percent, butterfly vertebrae in 30.0 percent, posterior embryotoxon in 43.3 percent, and a characteristic facial appearance in 100 percent. At study conclusion, of these 30 patients, eight had died (26.7 percent); six related to Alagille syndrome. Five patients died of a liver disease complication. Liver transplantation was carried out in five of the 30 patients (16.7 percent) and one of these died due to hyperacute rejection. At age two, cholestasis improved in 17 of the 30 patients. Those who had severe cholestasis at 2 years of age tended to have a complication, such as liver cirrhosis or liver transplantation, or to have died. Conclusion : Hepatic complications account for the most mortalities in patients with Alagille syndrome. Careful and complete assessments should be made in children who have cholestasis at 2 years of age. Further investigations of more cases are required.

• Journal of the Korea Convergence Society
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• v.9 no.8
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• pp.185-198
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• 2018

This paper was written for the purpose of using as the theoretical basic data of judgment in the situation that there is a growing demand for intelligent design theory to be taught in public schools along with evolution theory. In order to verify the possibility that intelligent design theory, which has little empirical evidence unlike evolutionary theory, could be a scientific theory, what intelligence is and whether the trace of intelligence is actually found in nature was confirmed through literature. If intelligent elements, which are traces of intelligence in nature, are discovered empirically in nature, then intelligent design theory can be recognized as a scientific theory and can also be taught in public schools. The identity and traces of intelligence were found in relevant literature and the traces are found not only in various artificial products derived from human beings such as thinking, knowledge, and civilization, but also in all phenomena of nature. Based on these results, this paper provides a discussion on how the evolutionary theory and intelligent design theory should be handled in the field of school education, as well as how to resolve the conflicts between evolutionary theory and intelligent design theory.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.2 no.2
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• pp.178-184
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• 1999

Purpose: The aims of this study were to evaluate the clinical manifestations and prognosis of the syndromic and nonsyndromic intrahepatic bile duct paucity (IHBDP). Methods: We studied histology of 42 infants with neonatal cholestasis. Fourteen patients were diagnosed as IHBDP. We evaluated the clinical manifestations, courses and prognosis retrospectively. Results: Underlying disease of the 42 infants with neonatal cholestasis were biliary atresia in 23, intrahepatic bile duct paucity in 14 (Alagille syndrome in 4 and nonsyndromic IHBDP in 10), neonatal hepatitis in 5 infants. The mean ratio of the bile ducts per portal tract was 0.087 (range: 0~0.5). The manifestations in 4 patients with Alagille syndrome demonstrated as follows: characteristic face in 3, chronic cholestasis in 4, posterior embryotoxon in 2, vertebral anomalies in 2, peripheral pulmonary stenosis in 2. One of 4 patients of Alagille syndrome improved cholestasis and the other 3 patients were remained their cholestasis and growth retardation. All patients of the nonsyndromic IHBDP were idiopathic. Seven out of 8 patients of nonsyndromic IHBDP showed improvement of cholestasis, and one patient received liver transplantation due to cirrhosis. Conclusion: This study suggested that IHBDP should be considered in the differential diagnosis of neonatal cholestasis. The outcome of idiopathic IHBDP was better than predicted.

• Proceedings of the Korean Statistical Society Conference
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• 2004.11a
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• pp.97-103
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• 2004

인력계획업무를 체계적이고 과학적으로 수행하기 위해서는 다양한 계량적인 모형이 요구된다. 이 중에서 핵심적인 모형은 미래의 인력운영을 시뮬레이션 할 수 있는 인력운영예측모형, 인력구조, 인사제도, 인력흐름간의 수리적인 관계를 분석하는 인력구조 분석모형, 인력운영 목표를 달성하기 위한 진급계획 최적화 모형 등이다. 본 논문에서는 이러한 모형 개발 시 적용한 통계적 방법론을 설명하고 주요 통계적 이슈를 제기하였다