• 대한토목학회논문집
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• 제28권2D호
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• pp.191-203
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• 2008

사업용 자동차 교통사고 특성 분석(도로교통안전관리공단, 2007)에 따르면, 사업용 차량의 1만대 당 교통사고 발생률과 사망률이 비사업용 차량에 비해 각각 6.7배와 5.3배 높은 것으로 나타났다. 또한 최근 10년 동안 전체 교통사고는 연평균 1.5% 감소한데 비하여, 사업용 차량의 교통사고는 연평균 2.0%씩 증가하는 추세를 보이고 있다. 최근 10년 동안 사업용 차량 중 버스와 화물트럭의 교통사고 발생건수는 꾸준히 감소하였다. 그러나 택시의 교통사고 발생건수만은 연평균 5.6%씩 꾸준히 증가하고 있다. 이와 같은 상황에서 심리성격 분석 기법인 Q분석을 통하여, 택시 운전자의 운전 성향별 특성을 파악하고, 운전 성향별 교통사고 저감대책을 마련하고자 하였다.

• 산경연구논집
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• 제15권3호
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• pp.21-29
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• 2024

Purpose: Electronic vehicles (EV) consumption become more prevalent among Vietnamese consumers. This paper aims to empirically assess the determinants of EV purchase intention among Vietnamese consumers. The research findings are expected to promote the consumption of electric vehicles in Vietnam. Research design, data and methodology: The quantitative research approach employed the Exploratory Factor Analysis (EFA). The sample size includes 301 respodents. Research design unified Theory of Acceptance and Use of Technology (UTAUT) and UTAUT2. The data collection process employ the non-probability sampling. Questionaire survey consists of 24 questions given to respondents via Google Form link. Data is processed by SPSS version 20 software. Results: The results proposed 04 determinants of the intention to buy electric vehicles: Government Support, Environmental Concern, Price Value, and Performance. Conclusions: Theorectical implications and managerial implications are also discussed to promote the consumption of electronic vehicles in Vietnam. Besides, the findings show that Price value, Environmental Concern and Performance positively affect the purchase intention of EV among Vietnamese consumers. Remarkably, Government Support is proven to be an insignificant factor in EV purchase intention. The call for further research rely on the role of government support in order to promote EV consumption in Vietnam and other emerging markets worldwide.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 학술대회 논문집 정보 및 제어부문
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• pp.427-428
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• 2008

In order to probe such mineral resources, AUVs (Autonomous Underwater Vehicles) have been used instead of ROVs (Remotely-Operated Vehicles) that are not suitable to probe submarine resources distributed over a wide area. However, the power consumption of AUVs needs to be reduced as they are operated by batteries. In controlling the power of underwater vehicles, the efficiency of batteries and their capacity have been heightened. This study aimed at developing a power control system suitable to the prober for submarine mineral resources. As a result, power was reduced as compared to the non-control system and the prober could explore the seabed longer than usual.

• 한국산학기술학회논문지
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• 제10권7호
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• pp.1729-1734
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• 2009

해마다 전 세계적으로 약 4천만 대, 우리나라에서는 약 55만 대의 자동차가 그 수명을 다하고 폐차장으로 보내지고 있다. 폐차에 의한 환경오염을 줄이기 위하여 각 국은 규제를 강화하고 있으며 EU(European Union)에서는 현재 84%에 머무르고 있는 재활용율을 2015년까지 95%로 올릴 것을 요구하고 있다. 자동차 중량의 75%를 차지하는 철은 95% 이상의 높은 재활용율을 보이고 있으나 나머지 25%를 구성하는 플라스틱, 유리 고무 등의 비금속류와 구리, 니켈 알루미늄 등의 비철금속류는 재활용율이 이에 미치지 못하고 있다. 따라서 95%의 재활용 요구를 만족시키기 위해서는 비철금속류의 재활용이 획기적으로 향상되어야 한다. 본 논문에서는 자동차에서 가장 많이 사용되는 비철금속인 구리와 니켈 재활용 향상을 통하여 전체 재활용율 변동을 산출하고자 한다.

• 산업경영시스템학회지
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• 제19권40호
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• pp.107-117
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• 1996

This paper considers the part assignment to workstations in flexible manufactuirng system (FMS). Parts are processed through several workstations according to processing order. The machines of each workstation can do multiple Processing functions. Therefore, a processing of a part can be processed in several workstations, which are non-identical in functional performance. Although a processing of a part can be processed in the multiple workstations, it has to be processed in only one among available several workstations, Parts are transported with unit load by automated guided vehicles (AGVs). The criteria of part assignment is to minimize the maximum value of the processing times of each workstation and the total transport times of vehicles. Model formulation is suggested, and numerical example is shown.

• 산업경영시스템학회지
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• 제22권52호
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• pp.117-139
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• 1999

This paper is concerned about the hybrid tandem configuration as the design of the automated guided vehicle system(AGVs). The hybrid tandem configuration is that the manufacturing system is divided into several non-overlapping zones, workstations of each zone are linked by network configuration including loop. That is, the manufacturing system is divided into several non-overlapping small size networks, and at most two automated guided vehicles can be available in each network. The transit point is located at proper point between adjacent networks. The parts are transported to workstations in other network through the transit points. One of the objective functions in dividing into the hybrid tandem configuration is to minimize the maximum travel time of the divided networks, and other is to minimize the total travel distance of parts moved to workstations in other networks for the next processing. The model formulation is presented, and a numerical example is shown. Also, the performances of system for the hybrid tandem, tandem and network configuration are compared through the simulation. The results of this research will contribute to the development of material handling systems in the manufacturing system. Also, it will be applied in determining the transportation area of transportation vehicles and the number and size of the transportation fleet in the transportation problem of logistics management.

• 산업경영시스템학회지
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• 제45권3호
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• pp.40-48
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• 2022

An automated material handling system (AMHS) has been emerging as an important factor in the semiconductor wafer manufacturing industry. In general, an automated guided vehicle (AGV) in the Fab's AMHS travels hundreds of miles on guided paths to transport a lot through hundreds of operations. The AMHS aims to transfer wafers while ensuring a short delivery time and high operational reliability. Many linear and analytic approaches have evaluated and improved the performance of the AMHS under a deterministic environment. However, the analytic approaches cannot consider a non-linear, non-convex, and black-box performance measurement of the AMHS owing to the AMHS's complexity and uncertainty. Unexpected vehicle congestion increases the delivery time and deteriorates the Fab's production efficiency. In this study, we propose a Q-Learning based dynamic routing algorithm considering vehicle congestion to reduce the delivery time. The proposed algorithm captures time-variant vehicle traffic and decreases vehicle congestion. Through simulation experiments, we confirm that the proposed algorithm finds an efficient path for the vehicles compared to benchmark algorithms with a reduced mean and decreased standard deviation of the delivery time in the Fab's AMHS.

• 한국정밀공학회지
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• 제17권2호
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• pp.121-129
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• 2000

The robotic automation in NonDestructive Testing(NDT) is a promising field of research and it helps to expand the applications of NDT enormously. Especially, in the case of pipelines which are widely used in various industrial facilities, it is required to secure adequate ways of inspection in the usual maintenance activitites. In this paper, we present a robot system for inpipe inspection of underground urban gas pipelines. The robot is configured as an articulated structure like a snake with a tether cable. Two active driving vehicles are located in front and rear of the system, respectively and passive modules such as a NonDestructive Testing module and a control module are chained between the active vehicles. The proposed system has outstanding mobility by employing a new steering mechanism called Double Active Universal Joint, which makes it possible to cope with complicated configurations of underground pipelines. Characteristic features of the system are described and the construction of the system is briefly outlined.

• 산업경영시스템학회지
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• 제42권1호
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• pp.8-20
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• 2019

The vehicle routing problem is one of the vibrant research problems for half a century. Many studies have extensively studied the vehicle routing problem in order to deal with practical decision-making issues in logistics. However, developments of new logistics strategies have inevitably required investigations on solution methods for solving the problem because of computational complexity and inherent constraints in the problem. For this reason, this paper suggests a simulated annealing (SA) algorithm for a variant of vehicle routing problem introduced by a previous study. The vehicle routing problem is a multi-depot and multi-trip vehicle routing problem with multiple heterogeneous vehicles restricted by the maximum permitted weight and the number of compartments. The SA algorithm generates an initial solution through a greedy-type algorithm and improves it using an enhanced SA procedure with three local search methods. A series of computational experiments are performed to evaluate the performance of the heuristic and several managerial findings are further discussed through scenario analyses. Experiment results show that the proposed SA algorithm can obtain good solutions within a reasonable computation time and scenario analyses show that a transportation system visiting non-dedicated factories shows better performance in truck management in terms of the numbers of vehicles used and trips for serving customer orders than another system visiting only dedicated factories.

• 산업공학
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• 제23권2호
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• pp.164-175
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• 2010

In logistics e-marketplaces, brokerage agents intermediate empty vehicles and freights registered by car owners and shippers. In the previous research, we proposed constant periodic/fixed matching algorithms for the logistics brokerage agents with the objective of minimizing the total transportation lead time and the transportation due date tardiness of freights(Jeong, 2004; Jeong, 2007). However, the constant type algorithms cannot consider changes in the balance status of an e-marketplace, i.e. the difference between the numbers of freights and vehicles to wait for matching, because they use non-changing matching periods and amounts. In this paper, we propose variable type algorithms for the logistics brokerage agent, in which the matching periods and amounts are changed continuously by considering the balance status between the freights and vehicles. In order to compare performance of the variable type algorithms to the previous constant type algorithms, we carried out computational experiments on various problem instances. The results show that the variable type algorithms give better performance than the constant type algorithms. We can expect that the logistics brokerage agents can improve their performance by using the proposed variable periodic/fixed matching algorithms.