• Journal of Korean Society of Transportation
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• v.23 no.7 s.85
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• pp.53-61
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• 2005

The Seoul City Government recently reformed the entire public transport system in an effort to prevent further deterioration in urban bus system's performance and service level. To analyze into impact on the productivity of Seoul's urban bus firms, this paper measures firm-level technical efficiency and productivity change with data envelopment analysis and Malmquist index approach. The paper then conceptualizes that these forms produce three kinds of output (bus-kilometers, passengers, or bus-kilometers and passengers) using five inputs (driver, maintenance, management, vehicle and fuel). The findings show that most (over one half) firms experienced a decline (an improvement) in productivity in the case of specifying only bus-kilometers (passengers) as output. As a result, it is discovered that an average firm had no change in productivity in the case of combining bus-kilometers and passengers as output. This is because the efficiency of an average firm declined due to increase in employees per bus and to an decrease in kilometers per bus. while its effectiveness improved due to an increase in passengers per bus which was caused by an increase in routes and a change in fare structure.

• Journal of Korean Society of Transportation
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• v.21 no.4
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• pp.29-44
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• 2003

A balanced evaluation system for a bus route network was proposed for a mid-sized suburban city. The evaluation system consists of 7 criteria-accessibility, riding comfort. transfer rate, directness of route, productivity of operation, regional equity, and minimum requirement of bus fleet - and quantitative indicators representing each of the criteria. The proposed system was applied in Siheung, a suburban city in Seoul Metropolitan Area. Four alternative scenarios of bus route network including the existing one were evaluated. The results showed that the suggested criteria and indicators are acceptable for the evaluation of a bus route network. In order to enhance the proposed evaluation procedure, further studies on the normalization of produced values and weights for each of the indicators are needed.

• Journal of Korea Multimedia Society
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• v.15 no.11
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• pp.1319-1329
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• 2012

AGVs are more and more utilized nowadays and magnetic guided AGVs are most widely used because their system has low cost and high speed. But this type of AGVs requires high infrastructure building cost and has poor flexibility of navigation path layout changing. Thus it is hard to applying this type of AGVs to a small quantity batch production system or a cooperative production system with many AGVs. In this paper, we propose a vision based guideline interpretation technique that uses the cheap, easily installable and changeable color tapes (or paint) as a guideline. So a vision-based AGV with color tapes is effectively applicable to the production systems. For easy setting and changing of AGV navigation path, we suggest an automatic method for interpreting a complex guideline layout including multi-branches and joins of branches. We also suggest a trace direction decision method for stable navigation of AGVs. Through several real-time navigation tests with an industrial AGV installed with the suggested technique, we confirmed that the technique is practically and stably applicable to real industrial field.

• Journal of Korean Society of Transportation
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• v.26 no.4
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• pp.77-86
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• 2008

Firstly, this study is to compare two types of productivity changes in Seoul's urban bus industry by public transport reforms: one with considering accident costs (ML), the other without considering accident costs (M). The directional distance function (DDF), which is a form of data envelopment analysis, and the Malmquist (Luenberger) productivity index (ML, M) are used for the analysis. The results show that productivity increased regardless of accident costs over time, and the ML index is a little higher than the M index, which means that most firms experienced more of a reduction ratio of accident costs than a reduction ratio of inputs. Secondly, this paper is to analyze how reforms affect productivity changes. The results show that operational speed improvements or passenger increases most affect productivity increases, which means that the installment of median bus lanes or introduction of free transfers among public transport modes were effective in reducing both inputs and accident costs. However, operational system reforms including mid-public management were related with productivity changes but they were not as effective.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.29 no.1
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• pp.377-382
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• 2005

This paper deals with productivity improvement of stevedoring system by pooling opertaions of transport vehicle at automated container terminal. Usually, in traditional container terminals, grouping operations of transport vehicle are applied for container crane because vehicle routing path is simple and vehicle assignment is easy. But this static assignment(SA) operation that arrsign vehicles to container crane ar apron reduces flexibility of vehicles. Therefore, This paper presented 4 dynamic assignment(DA) method to improve efficiency of vehicles. These 4 dynamic assignment method consider present situations of container crane such as sequence(Se), queue time(Qt), productivity(Pr), numeric of vehicle assignment(Nv), numeric of buffer(Nb) at vehicles assignment. At the results, dynamic assignment operation to consider Qt, Nv, Nb is most efficient and by next time, dynamic assignment operation to consider Se is superior more than static assignment operation. but, dynamic assignment operation to consider Pr or Qt of container crane only is inefficient than static assignment operation.

• Proceedings of the KOR-KST Conference
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• 1997.12a
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• pp.1-12
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• 1997

우리 나라 자동차운송산업에 존재하는 지입제(위탁관리제)는 과거부터 논란의 대상이 되어 왔다. 1950년대 말부터 시작된 육운 분야의 직영화 정책은 노선버스나 택시의 경우 비교적 성공적인 결과를 가져왔으나 화물자동차운송과 전세버스분야에서 만큼은 아직도 대다수 사업장에서 지입제가 관행화된 제도로 남아 있다. 지입제도는 비효율적이고 전근대적인 경영기법으로 인식되고 있으며 산업발전의 저해요인 보기도하고 불가피하다고 평가되기도 하였다. 본 논문에서는 지입제를 단순하게 비합리적인 제도라고 보기보다는 나름대로의 장점을 가지고 있어 합법적 또는 비합법적인 형태로 지금까지 유지되고 있다고 본다. 지입제는 정보가 비대칭적인 상황에서 기업조직을 통해 생산과 판매를 하기보다는 시장거래를 통한 계약을 통하여 운송서비스를 생산 및 판매를 함으로써 유인일치를 달성시킬 수 있다는 것을 보여주고 있다. 장거리를 운행하는 운송사업의 경우 사업자와 고용운전자는 노동성과에 대한 비대칭적인 정보를 가질 수밖에 없게 된다. 이는 대리문제를 야기시켜 기업조직에 의한 운송서비스의 공급은 생산비용을 상승시킨다. 반면 자동차운송서비스는 생산단위를 분리하기 위한 비용이 비교적 적어 독립적인 운영이 가능하다. 따라서 차량을 1대씩 분리하여 사업권을 시장거래하는 지입제를 운송사업자와 운전자는 선택하게 된다는 것이다.

• Proceedings of the KOR-KST Conference
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• 1997.12b
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• pp.1-14
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• 1997

우리나라 자동차운송산업에 존재하는 지입제(위탁관리제)는 과거부터 논란의 대상이 되어왔다. 1950년대 말부터 시작된 육문 분야의 직영화 정책은 노선버스나 택시의 경우 비교적 성공적인 결과를 가져왔으나 화물자동차운송과 전세버스분야에서 만큼은 아직도 대다수 사업장에서 지입제가 관행화된 제도로 남아 있다. 지입제도는 비효율적이고 전근대적인 경영기법으로 인식되고 있으며 산업발전의 저해요인 보기도하고 불가피하다고 평가되기도 하였다. 본 논문에서는 지입제를 단순하게 비합리적인 제도라고 보기보다는 나름대로의 장점을 가지고 있어 합법적 또는 비합법적인 형태로 지금까지 유지되고 있다고 본다. 지입제는 정보가 비대칭적인 상황에서 기업조직을 통해 생산과 판매를 하기보다는 시장거래를 통한 계약을 통하여 운송서비스를 생산 및 판매를 함으로써 유인일치를 달성시킬 수 있다는 것을 보여주고 있다. 장거리를 운행하는 운송사업의 경우 사업자와 고용운전자는 노동성과에 대한 비대칭적인 정보를 가질 수밖에 없게 된다. 이는 대리문제를 야기시켜 기업조직에 의한 운송서비스의 공급은 생산비용을 상승시킨다. 반면 자동차운송서비스는 생산단위를 분리하기 위한 비용이 비교적 적어 독립적운영이 가능하다. 따라서 차량을 1대씩 분리하여 사업권을 시장거래하는 지입제를 운송사업자와 운전자는 선택하게 된다는 것이다.

• Journal of KSNVE
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• v.14 no.4
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• pp.16-28
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• 2004

항공우주산업은 항공기나 우주비행체를 생산하는 모든 관련 산업으로 정의할 수 있다. 소음진동측면에서 보면 항공기는 운송수단의 하나로 사용되므로 소음 관련 규제 법률에 따라서 관련기술의 발전이 이루어져 왔다고 볼 수 있으나 우주비행체는 운행공간을 고려 할 때 소음진동기술이 작동효율성 (연소불안정성, 공진파괴 등)을 향상시키기 위한 기술로 사용되어 왔고 그 범위도 매우 제한되어 있다. 따라서 소음진동기술은 주로 항공기 분야에서 많은 응용을 구하고 있는 실정이다. (중략)

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.6
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• pp.957-965
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• 2018

This study presents a geographic information system based dump truck route exploring system (DRES) which provides construction managers and hauling operators with efficient route information that can improve earthmoving productivity by reducing hauling time. The system is comprised of Network Analyst from Esri as a route exploring engine and a network data model. The network data model includes information on weight limit of bridges, height limit of pedestrian overpasses, and one way that impedes dump trucks' hauling efficiency. A construction manager is expected to input origin and destination point in the user interface, and the system generates an efficient route that avoids bridges with weight limit or pedestrian overpasses with height limit. The system was applied to a real earthmoving project to test its applicability, and it was found that the system functions as intended.

• Journal of Navigation and Port Research
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• v.28 no.10 s.96
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• pp.891-897
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• 2004

This paper provided a simulation model for transport vehicles that carry container from the ship to yard block and vice versa at automated container terminal with a perpendicular yard layout. Usually, the efficiency of container terminal is evaluated by the productivity of container cranes at apron, and the stevedoring system for transport vehicles and yard cranes should be supported enough to improve productivity of container cranes. Especially, transport vehicle is very important factor in the productivity of container cranes and the performance of transport vehicles are changed according to the number and traveling type of vehicles. For these reason, a method that can estimate productivity of transport vehicle is required Finally, we developed the simulation model to analyze the productivity of transport vehicle and presented the productivity of container cranes for a varying operation of transport vehicles.