• Journal of Korean Society of Transportation
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• v.23 no.3 s.81
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• pp.85-94
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• 2005

The scale and operating conditions of logistical systems very sensitively varies according to the variation of traffic intensity that is affected by the arrival characteristics of trucks and the attributes of loading/unloading services in logistics facilities. More exactly, logistics costs are incurred according to variations of traffic intensity. which are intimately linked with in a given time period. Also. although traffic intensity changes minutely, the range of cost variation is wide. Nevertheless, with regard to operating logistics systems, the existing studies make no attempt to analyze these factors. Therefore, it was the purpose of this study to determine the optimal traffic intensity to minimize excessive logistics costs resulting from the generation of unnecessary costs such as waiting costs and overcosts in operating a facility. For the purposes of this analysis. a determination model of optimal traffic intensity was constructed according to queuing theory. The inflow/outflow conditions of trucks and the terminal operational conditions were collected from an off-dock container terminal in Busan. On the basis of this data. the optimal traffic intensity that could off-set excessive waiting and operating costs was determined quantitatively. Also. using the optimal traffic intensity to be determined. we consider the improvements of operating system in the logistics facilities.

• 도로교통
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• s.82
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• pp.23-33
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• 2000

• Journal of Korean Society of Transportation
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• v.25 no.4
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• pp.123-133
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• 2007

This study analyzed whether a transit network with hierarchy is efficient or not, and if transit network hierarchy has cost efficiency, then which condition guarantees the efficiency of the transit network hierarchy. The authors modeled the total cost of the transit network and suggested the conditions in which the transit network hierarchy has cost efficiency through comparing the cost of the transit network with and without hierarchy. The efficiency of transit network hierarchy is guaranteed when the travel cost savings induced by using a higher hierarchy transit network is larger than the increasing non-travel cost, which is the sum of access cost, waiting cost, and operating cost, induced by the introduction of a higher hierarchy transit network. This result is consistent with common sense and with the concept of cost and benefit analysis. If a passenger traveling within the area divided by a higher hierarchy transit network uses only a lower hierarchy transit network and the passenger traveling out of the area divided by the higher hierarchy transit network uses both lower and higher hierarchy transit networks, the travel demand using the higher hierarchy transit network is inversely proportional to the square of the line spacing. This means that the transit network becomes more efficient and small increases of travel demand guarantee the efficiency of the transit network hierarchy as the connectivity of the network becomes higher. This result shows that transit networks have economies of aggregation. This study is the first analytical research on transit network hierarchy and is expected to be a basis for numerical research. However, numerical research should complement this study, since analytical research has some limitations for considering a real network.

• Journal of Korean Society of Transportation
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• v.25 no.6
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• pp.129-140
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• 2007

The planning procedure of a transit operation consists of design, operation, and evaluation according to the research characteristics. There are some review studies on the operation and evaluation procedure, but the research on the design procedure has not yet been organized systematically. In this study, the research on transit system design was reviewed and the model structure and its solution method were arranged. The decision variables of the design procedure are network structure, line spacing or position, stop spacing, dispatching headway, and fleet size. In the analytical research on design procedure, system total cost is generally used as the objective function. System total cost is comprised of user cost, which is the sum of user access, waiting, and travel cost, and operating cost. Total cost of the transit system, used as the objective function, has the unique minimum because it is differentiable. There is a certain decision variable that makes the derivative of the objective function equal to zero and the second derivative of the objective function is positive. Therefore the decision variable that makes the first derivative of the objective function zero is the optimum that minimizes the objective function, and each of the cost components of the objective function become the same. This study is expected to help understanding about the research on the design procedure of transit operation planning and to help be a catalyst for relevant research.

• Journal of Korean Society of Transportation
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• v.2 no.1
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• pp.69-88
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• 1984

통행시간가치에 대한 연구는 독립변수를 이용한 통행시간과 비용에 의한 선택모형 을 대개 사용하여 왔다. 통행시간과 비용에 대한 매개함수를 추정한 후에 통행시간가치를 교통시간과 비용의 $\ulcorner$파라메타$\lrcorner$비로써 얻고 있다. 그러나 통행시간가치에 관한 신뢰구간과 통계적 유의성을 설정하기 위한 적절한 과정은 아직 연구되지 않고 있으나 $\ulcorner$로-짓$\lrcorner$ 모형 자체에 대하여는 되어있다. 본 논문은 통행시간가치를 측정하기 위한 기존의 방향을 비평적 으로 검토하여 본 것으로 통행시간가치를 통계적 유의성 검증을 위한 표준화 과정은 아직 이론적으로 정립 가능하다고 생각되지 않지만 통행시간가치평가의 간편식을 제시하여 보았 다. 간편식에 의하여 제시된 결과에 의하면 선택모형에 입각한 통행시간가치의 통계적신뢰 구간이 매우 큰 것으로 나타났는바 이에 대한 선택모형에 입각한 통행시간가치 측정을 위한 과정의 타당성에 대한 많은 의문이 아직도 남는다 하겠다.

• Journal of Korean Society of Transportation
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• v.28 no.6
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• pp.17-24
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• 2010

As various social problems occur due to increasing traffic accidents, the government has setup and executed strong safety policies. As a result, the number of traffic accidents and the death toll have been decreasing in recent years. However, the setup and execution of the various policies for reducing traffic accidents cost much, so it is necessary to evaluate the cost-effectiveness of each policy. In the present study, enforcement by means of an unmanned over-speed enforcement system, the enforcement effect of which was proven good compared to the cost required for traffic enforcement, is compared with enforcement by policemen. As a result of the comparison, the average speed was 82.66 km/h before the use of unmanned systems and policemen; the average speed with manned enforcement was 70.57 km/h; and the average speed with unmanned systems was 67.85 km/h. The speed limit violation rate was 65% before the use of unmanned systems and policemen; 32% with manned enforcement; and 15% with unmanned systems. Considering the kinds of vehicles, the average speed and violation rate were highest among private cars, then vans, and then trucks.. Considering lanes. The accident rate was estimated based on the above results, and the input cost-to-advantage was estimated. The annual cost-to-advantage was estimated by comparing the above estimated values with the conditions before the unmanned over-speed enforcement system. Subsequently, the enforcement by policemen showed a negative advantage of 76,130,590 won, and the enforcement by the unmanned system showed a positive advantage of 38,577,670 won.

• Proceedings of the Korea Water Resources Association Conference
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• 2004.05b
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• pp.771-776
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• 2004

치수사업에서 실시하는 경제성분석은 계획하고 있는 사업의 사회적 후생의 극대화 측면에서 경제적 타당성을 분석 평가하는 것으로서 일반적으로 편익${\cdot}$비용분석이 사용되고 있다. 이러한 경제성분석시의 문제점으로 직접편익뿐 아니라 간접편익 및 비계량편익에 해당하는 사업의 효과도 편익부분의 계산에 포함할 수 있는 방법이 필요한 실정이다. 이에 따라 본 연구에서는 홍수에 의한 교통두절로 인한 피해를 간접편익으로 고려하여 오산천지역에 적용해 보았다. 교통두절피해 편익의 항목으로서 주로 차량운행비용 절감과 통행시간비용 절감의 두 항목을 고려하였으며, 이 두 항목에 내한 결과에서 홍수지체시간당(단위 1일당) 적지 않은 편익이 발생하는 것으로 나타났다. 본 연구를 통해 일반적인 치수사업 경제성분석에서 이뤄지지 않았던 교통두절에 의한 피해항목을 간접편익으로 고려함으로써 홍수로 인한 교통두절피해를 정량적으로 계량할 수 있었으며, 실질적으로 편익에 영향이 가장 큰 편익가치(재화가치, 시간가치)에 대한 연구가 계속적으로 수반된다면 이후의 다른 치수사업 경제성분석시에 효과적인 분석이 이뤄질 것으로 판단된다.

• Journal of Navigation and Port Research
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• v.31 no.10
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• pp.819-824
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• 2007

This paper studied safety benefit of operation-effectiveness analysis on marine traffic safety facilities. In the operation-effectiveness of marine traffic safety facilities the benefits can be divided as safety benefit, transport benefit, and other benefit. Safety benefit was produced as the loss aversion cost of marine traffic caused by the reduction of marine accidents after establishing and operating marine traffic safety facilities. First of all the reduction rate marine accidents was estimated to do it, and the detail model of loss aversion cost was constructed Then each variable in the model was defined and the method of computation presented.

• Proceedings of the KOR-KST Conference
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• 1998.10b
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• pp.465-465
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• 1998

버스운영에 관한 최적화 모형에는 총 시스템 비용의 최소화 모형과 사회적 편익의 극대화 모형이 있다. 이들 모형들은 해석적 방법에 의해서 특정 이상화된 문제를 연구했다. 특정 필요조건들을 충족시키면서 최적 버스크기, 서비스 빈도, 보유대수를 결정하려고 애썼다. 그러나 실제 버스의 운행시간은 정류장의 지체시간과 승객의 수요에 따라 변화하고 승객의 비용추정시 접근시간을 현실적으로 고려하지 못해 버스 운영의 비효율성을 초래하기 쉽다. 본 연구의 목적은 시간대별로 이용자와 운영자의 비용의 합으로 구성된 총 교통 모형을 최소화는 모형을 구축하는 것이다. 본 논문에서는 기존의 문헌에서 충분히 고려하지 않은 정류장 간격에 따른 이용자의 접근시간과 버스가 정류장에 들어가고 나올 때의 감·가속으로 인한 지체와 승객의 승·하차로 인한 지체를 고려한 버스의 정류장 정차시간을 기존의 모형에 추가시켜서 운행간격, 버스정류장의 정차시간, 정류장 간격 및 보유대수를 결정하는 방법을 제안했다. 아울러 실제 서울시에서 운행되고 있는 시내버스 노선에 대해 사례분석을 통해서 본 모형을 실제 적용해보고 기존의 운영비용과 비교하고 본 모형의 유효성을 검증할 예정이다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.05a
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• pp.133-134
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• 2019

우리나라는 협소한 국토구조 특성상 도로운송 위주의 화물운송체계가 정착되어 있어 내륙수송비 부담 증가, 교통 혼잡, 대기오염 및 소음, 도로파손, 대형교통사고 등 크고 작은 문제가 지속적으로 ${\cdot}{\cdot}{\cdot}{\cdot}$(중략)${\cdot}{\cdot}{\cdot}{\cdot}$ 따라서 본 연구에서는 물류비용 및 서비스를 좌우하는 수송비용과 물류인프라 초기투자비용을 최소화하면서 교통 혼잡, 온실가스배출 등 사회 환경 비용을 절감하기 위한 단절없는 인터모달 자동화물운송 시스템 개념을 정립하고 구성요소 및 요소기술을 ${\cdot}{\cdot}{\cdot}{\cdot}$(중략)${\cdot}{\cdot}{\cdot}{\cdot}$