• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2013.10a
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• pp.58-60
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• 2013

부산항 입항 및 출항 대기, 통과 선박의 중간 기항지로 이용되는 부산 남외항 대기 정박지는 N-1~N-5으로 구성되며 현재, 최대 90척이 동시에 정박 가능한 집단 정박지 지정방식으로 지정되어 있다. 부산 남외항 대기 정박지는 입 출항 선박 및 통과 선박, 급유선 등의 교통에 따른 충돌, 접촉 등의 해양 사고와 갑작스러운 돌풍 등 기상악화에 따른 충돌, 접촉 및 좌초 등의 해양 사고가 발생하고 있다. 부산 남외항 대기 정박지의 자연 환경, 이용현황, 기상, 입 출항 선박 및 통과 선박의 교통 흐름을 종합적으로 살펴보고 부산 남외항 대기 정박지에서 발생하는 해양사고를 분석하였다. 따라서 부산 남외항 대기 정박지의 운영상의 문제점을 찾고, 해상교통조사 설문조사 이론적 근거를 기초로 안전도 평가 시스템을 사용하여, 향후 개선방향을 제시하였다.

• Journal of Korean Society of Transportation
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• v.17 no.2
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• pp.179-191
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• 1999

To device effective freeway traffic flow control strategies and freeway traffic information dissemination strategies, it is very important to estimate real physical queue length on the freeway. Shock wave theory and queueing theory have limitation to be used to estimate the queue length. The primary objective of this study is to develop a reliable method for estimating the physical queue length and level of congestion. Queueing propagation processes were analysed by using such traffic data as main line traffic volume, ramp volume, density. speed, and physical queue length collected by video photographing on Olympic Freeway. As a result of analysis, it has been confirmed that the real queue length can be estimated by using the traffic counts arriving the congested region and passing a bottleneck location. Further more, a reliable method for estimating the level of congestion could be developed on the basis of real-time traffic counts.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.40 no.3
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• pp.321-330
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• 2020

The purpose of this study is to present the appropriate standby space for the mechanical parking lot considered parking queue. This analysis is based on the field-study by results of the influential factors on the parking queue of mechanical parking lots in the commercial area of Gwang-ju metropolitan city. In this study, the parking queue was analized through the simple modeling using Vissim based on average service rate and average arrival rate from the result of field-study. As a result of applying the field survey products to the theoretical queue model, no significant result was obtained when the traffic intensity exceeded 1. Therefore, parking queue was analyzed through simple modeling using Vissim, and the model for calculating the proper parking queue size of the mechanical parking lot by size was derived. The model for estimating of an appropriate mechanical parking standby space considering parking queue presented in this study is expected to be a criterion for considering the appropriate parking space of a new building, and also it can be used to minimized the traffic impact due to the parking queue by the lack of standby space.

• Journal of Korean Society of Transportation
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• v.19 no.3
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• pp.101-113
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• 2001

Since late 1970s. one of the principal research areas in transportation problem is dynamic traffic assignment (DTA). Although many models have been developed regarding DTA, yet they have some limits of describing real traffic patterns. This reason comes from the fact that DTA model has the time varying constraints such as state equation, flow propagation constraint, first in first out(FIFO) rule and queuing evolution. Thus, DTA model should be designed to satisfy these constraints as well as dynamic route choice condition, dynamic user equilibrium. In this respect, link-based DTA models have difficulty in satisfying such constraints because they have to satisfy the constraints for each link, while path-based DTA models may easily satisfy them. In this paper we develop a path-based DTA model. The model includes point queue theory to describe the queue evolution and simulation loading method for depicting traffic patterns in more detail. From a numerical test, the model shows promising results.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.2
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• pp.22-34
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• 2011

This paper presents the investigation results of a research on how engineers can analyze the economic effect of the ETCS(Electronic Toll Collection System) installed to minimize the vehicle delays on freeway tollgates during toll payments. This research considered this economic effect to occur in the form of vehicle passing time reductions at the ETCS, and the multi-service queuing theory was applied to estimate these values. This research found: 1) When vehicles approaching tollgates show Poisson distribution and the service time of the ETCS shows Exponential distribution, the multi-service queuing theory would be applicable for estimating vehicle passing times at toll-gates, 2) Despite the ETCS placement, exit sections of tollgates give a greater reduction of vehicle passing times than entering sections due to more delays at conventional toll payments, and 3)The ETCS would not guarantee vehicle passing time reductions all the time, because in such a case as many vehicles were queuing at the ETCS, the total delay level for a toll gate would increase greatly. In addition, in order to examine the accuracy of the estimated vehicle passing values, this research compared the values from the multi-service queuing theory with the observed values from a set of field survey values at freeway toll-gates, and found that the two values were in a good agreement with a very low error range of 1-3 seconds per vehicle. Based on this result, the multi-service queuing theory was recommended for practice.

• Journal of the Korea Society for Simulation
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• v.17 no.3
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• pp.63-73
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• 2008

The aim of study is to analyze the berth occupancy rate according to the ship size. P Iron and steel company operate exclusive bulk terminal at P port and G port and the depth of water at berth are not so equal each other. And to reduce the sea transport cost between loading port and unloading port P and G, P company increases the number of large ship while ship scheduling. But it causes to increase the berth congestion at the specific water depth berth owing to the draught of large ship. At this point, usually ship waiting time starts to rise even at low levels of berth occupancy rate, and will rise more and more sharply at the level of full utilization. But it is not common at exclusive terminal like P port and G port. Bulk ships arrive at port according to the early planned arrival time and the coefficient of variation of ship arrival time is not so big. So queueing time at exclusive terminal does not rise sharply near 80-90 berth occupancy rate.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.19 no.2
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• pp.159-179
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• 2024

Based on the case of collaboration between large companies and startups, this study suggests the importance of establishing mutual cooperation and trust relationships for the success of open innovation strategy from the perspective of cooperative game theory. It also provides implications for how this can be implemented. Due to information asymmetry and differences in organizational culture and decision-making structures between large companies and startups, collaboration is likely to proceed in the form of non-cooperative games among players in general open innovation, leading to the paradox of open innovation, which lowers the degree of innovation. Accordingly, this study conducted a case study on collaboration between large company 'G' and startup 'S' based on the research question "How did we successfully promote open innovation through cooperative game-type collaboration?" The study found that successful open innovation requires (1) setting clear collaboration goals to solve the organizational problem between large companies and startups, (2) supporting human resources for qualitative growth of startups to solve reliability problems, (3) leading to strategic investment and joint promotion of new projects to solve the profit distribution problem. This study is significant in that it contributes to expanding the discussion of the success factors of open innovation to the importance of interaction and strategic judgment considering the organizational culture and decision-making structure among players, and empirically confirming the success conditions of open innovation from the perspective of cooperative game theory.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.05b
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• pp.397-398
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• 2003

대기 중 분진을 제거하는 방식으로 여과 이론을 적용할 수 있는 경우는 섬유 여과기, 입자상 여과기, 액적에 의한 습식 세정기 그리고 기포를 이용한 분진 제거 방법 등을 들 수 있다. 이러한 여과 원리를 이용한 집진 설비를 설계하는데 있어, 액적 또는 기포 주위의 유동장을 정확히 파악하는 것은 매우 중요하다. 특히, 포집구의 크기가 작아지고 화학적으로 반응성을 갖는 고온의 함진가스가 유입되는 경우 및 저압에서 운영되는 경우에 누드센수(Knudsen number)의 영향을 무시할 수 없는데 이러한 영역을 저 누드센 영역(low Kundsen number regime)이라고 한다(Lee et al., 1978). (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2001.11a
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• pp.89-90
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• 2001

최근의 대기확산 모델링 분야는 모델링 수행에 큰 장애요인이었던 계산속도에 의한 제한요소가 Computer H/W 성능의 향상으로 상당히 제거되면서, 학계의 연구를 통해서 보다 진보된 확산이론을 사용하는 새로운 개념의 모델들이 속속 개발되고 있다. 이 중, 일부 모델들은 2000년도부터 미국 EPA(환경보호청)으로부터 새롭게 추천받고 있는데, 근래 미국 EPA에서 새로이 추천하고 있는 모델로서 ISC3-PRIME, AERMOD, 및 CALPUFF이 있다. (중략)

• Journal of the Korean Institute of Intelligent Systems
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• v.10 no.2
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• pp.168-174
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• 2000

All the visiting customers makes a queue and then can be served at an unoccupied server, in the queueing system of multi-server. The customer and server, however, have a conflictive feeling of satisfaction at all times. To solve the problem, in this paper, it is proposed that new design method of server number to maximize the satisfaction level of customer and server by the hzzy concept which is applied to the queuing system.