• 복합신소재구조학회 논문집
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• 제6권3호
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• pp.62-68
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• 2015

As a preparation of a design standard regarding road facilities, such as cantilever columns for traffic lights, street lights on highways is proposed. Currently these minor structures are designed based on guidelines which are mixed with multiple old foreign specifications without any criteria in terms of safety and economy, which could lead irregular safeties and the loss of national properties. In the considered two cases for effective projected area, it is found that following efficient way of design without critical analyses could make significant errors and miscalculations. Therefore, a fundamental research on the minor structures is urgently needed.

• ETRI Journal
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• 제21권4호
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• pp.9-22
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• 1999

This paper considers a problem of configuring both physical backbone and logical virtual path (VP) networks in a reconfigurable asynchronous transfer mode (ATM) network where links are subject to failures. The objective is to determine jointly the VP assignment, the capacity assignment of physical links and the bandwidth allocation of VPs, and the routing assignment of traffic demand at least cost. The network cost includes backbone link capacity expansion cost and penalty cost for not satisfying the maximum throughput of the traffic due to link failures or insufficient link capacities. The problem is formulated as a zero-one non-linear mixed integer programming problem, for which an effective solution procedure is developed by using a Lagrangean relaxation technique for finding a lower bound and a heuristic method exploited for improving the upper bound of any intermediate solution. The solution procedure is tested for its effectiveness with various numerical examples.

• 한국경영과학회지
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• 제30권1호
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• pp.1-15
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• 2005

In this paper, we deal with a mesh network design problem arising from the deployment of WDM for the optical internet. The mesh network consists of mesh topology for satisfying traffic demand while minimizing the cost of WDM, OXC, and fiber cables. The problem seeks to find an optimal routing of traffic demands in the network such that the total cost is minimized. We formulate the problem as a mixed-integer programming model and devise a tabu search heuristic procedure. Also we develop an optical internet design system that implements the proposed tabu search heuristic procedure. We demonstrate the computational efficacy of the proposed algorithm, compared with CPLEX 8.0.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2002년도 춘계공동학술대회
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• pp.426-433
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• 2002

This paper deals with an offline routing problem, which can be used as an explicit routing procedure in MPLS(Multiprotocol Label Switching) network, for traffic engineering. This problem is formulated as an MIP(Mixed Integer Programming) with the objective function which is to minimize the sum of the maximum link utilization for load balancing (link utilization) and the routing cost. Constraints arc composed of link capacity restriction and demand requirement that has origin-destination pair, bandwidth requirement and hop restriction. The problem is proved to be NP-hard so that the Lagrangean relaxation method is applied to propose a Lagrangean heuristic. To test the effectiveness & efficiency of the proposed algorithm, computational experiments are performed with numerical instances. The experiment results show that the proposed algorithm solves the problem within a reasonable time.

• 한국경영과학회지
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• 제24권1호
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• pp.49-58
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• 1999

A new channel access function is proposed to enhance the performance of the Joint CDMA/PRMA. It is obtained in consideration of the number of terminals in reservation mode and the number of terminals in contention mode whose probability distribution is estimated by applying pseudo Bayesian approach. Simulation results show that the performance of the Joint CDMA/PRMA can be improved by applying new channel access function under voice-only traffic and mixed voice/random-data traffic.

• 대한교통학회지
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• 제17권2호
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• pp.105-114
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• 1999

본 연구에서는 시공간점유량을 이용하여 기존의 평가지표보다 더욱 합리적으로 보행자의 안전성 평가가 가능한 새로운 지표의 개발을 시도한다. 기존연구에서 자동차 교통량에 보행자 교통량을 곱하여 보차교착도라고 부르고 있고, 이것은 주민의 안전감과 밀접한 상관이 있는 것으로 밝혀졌다. 그러나 보차교착도에는 자동차의 속도개념이 누락되어 있으며, 통상 자동차의 속도와 안전감과 상관이 높은 것을 볼 때 아직 불충분한 것으로 사료된다. 따라서 본 연구에서는 시공간점유량이라는 개념을 이용하여 시공간노출량이라는 새로운 개념을 만들어내며 서울의 41개의 보차혼합공간에서 조사된 실제 데이터를 갖고 분석해본다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1023-1024
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• 2008

The road surface scripture season must be interpreted with hitherto whole aspect line scripture season different. TRAM (street cars) it respects an operation it stands and back must be operated the bus which runs place and riding grade different public transportation means and to be mixed. With the numerous crossroads zebra crossing and the coat platform must operate back. The role of the operation article most is important. It undergoes the influence of traffic signal specially directly. It considers each facility etc. of the road and must construct a proper equipment in him with connection method of the signal system which it follows in the middle urethra. Must secure the fixed time characteristic of the operation which road surface scripture season is efficient and expression speed and operation. In order the [le] according to interface plan with traffic signal it does to consider a traffic signal first of all. This the research of operation provision is necessary.

• 한국정보처리학회논문지
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• 제3권3호
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• pp.493-500
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• 1996

무선 메세지 전송, 무선 데이타 베이스, 이동 컴퓨팅 등에 대한 관심이 증대됨 에 따라 이동 데이타 서비스를 효과적으로 수용할 수 있는 방안이 절실하게 요구되고 있다. 본 논문에서는 음성 뿐만 아니라 다양한 데이타의 서비스 특성을 동시에 고려하여 음성과 데이타에 대해 보다 균형된 서비스 품질을 제공하기 위한 트래픽 처리 방법을 제안 하고 이 방법의 성능을 분석하였다. 성능분석 결과에 따르면 제안된 방법은 이전의 방법에 비해 데이타 품질을 개선할 수 있으며, 데이타의 부하 크기에 무관하게 허용가능한 수준의 음성 블러킹율을 동시에 제공할 수 있음이 확인되었다. 특히 메세지형 데이타서비스도 혼합된 환경 하에서는 성능향상 효과가 더 크다.

• 한국정보기술학회 영문논문지
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• 제10권1호
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• pp.15-23
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• 2020

In this paper, we propose a new method to detect traffic accidents in video from vehicle-mounted cameras (vehicle black box). We use the distance between vehicles to determine whether an accident has occurred. To calculate the position of each vehicle, we use object detection and tracking method. By the way, in a crowded road environment, it is so difficult to decide an accident has occurred because of parked vehicles at the edge of the road. It is not easy to discriminate against accidents from non-accidents because a moving vehicle and a stopped vehicle are mixed on a regular downtown road. In this paper, we try to increase the accuracy of the vehicle accident detection by using not only the motion of the surrounding vehicle but also ego-motion as the input of the Recurrent Neural Network (RNN). We improved the accuracy of accident detection compared to the previous method.

• 한국도로학회논문집
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• 제20권2호
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• pp.75-85
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• 2018

PURPOSES : This study aimed to analyze traffic accidents at circular intersections, and discuss accident reduction strategies based on land use and vehicle type. METHODS : Traffic accident data from 2010 to 2014 were collected from the "traffic accident analysis system" (TAAS) data set of the Road Traffic Authority. To develop the accident rate model, a multiple linear regression model was used. Explanatory variables such as geometry and traffic volume were used to develop the models. RESULTS : The main results of the study are as follows. First, it was found that the null hypotheses that land use and vehicle type do not affect the accident rate should be rejected. Second, 16 accident rate models, which are statistically significant (with high $R^2$ values), were developed. Finally, the area of the central island, number of speed humps, entry lane width, circulatory roadway width, bus stops, and pedestrian crossings were analyzed to determine their effect on accidents according to the type of land use and vehicle. CONCLUSIONS : Through the developed accident rate models, it was revealed that the accident factors at circular intersections changed depending on land use and vehicle type. Thus, selecting the appropriate location of bus stops for trucks, widening entry lanes for cars, and installing splitter islands and optimal lighting for motorcycles were determined to be important for reducing the accident rate. Additionally, the evaluation showed that commercial and mixed land use had a weaker effect on accidents than residential land use.