• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.331-332
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• 2006

Transport systems which are the important part of the factory automation have much influence on improving productivity. Object transport systems are driven typically by the magnetic field and conveyer belt. In recent years, as the transmission and processing of information is required more quickly, demands of optical elements and semiconductors increase. However, conventional transport systems are not adequate for transportation of those. The reason is that conveyor belts can damage precision optical elements by the contact force and magnetic systems can destroy the inner structure of semiconductor by the magnetic field. In this paper, the levitation transport system using ultrasonic wave is developed for transporting precision elements without damages. Vibration modes of each flexural beam are verified by using Laser Scanning Vibrometer.

• Journal of Korea Trade
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• 제25권1호
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• pp.18-33
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• 2021

Purpose - This paper investigates the causal relationship between logistics infrastructure development and the economic growth of Korea. Considering the industrial and economic structure of Korea, it is likely that logistics infrastructure is positively associated with the economic growth of the country. Design/methodology - The causal relationship between logistics infrastructure and economic development is estimated using Vector Autoregressive (VAR) and Vector Error Correction Model (VECM) considering long-run equilibrium between the two factors. To this end, a dataset consisting of 7 logistics infrastructure proxies and 5 economic growth indicators covering the period of 1990-2017 is used. Findings - It was found that causality, in general, runs from logistics infrastructure development to economic growth. Specifically, the results indicate that maritime transport is positively associated with the economic growth of Korea in terms of GDP and international trade. In addition, other modes of transport also have a positive impact on either the GDP or international trade of Korea. Originality/value - While existing studies in this area are based on either regional observations or a specific mode of transport, this study presents empirical evidence on causality between logistics infrastructure and the economic growth of Korea using a more comprehensive dataset. In addition, the findings in this paper can provide valuable implications for transport infrastructure development policies.

• 대한교통학회지
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• 제34권6호
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• pp.510-522
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• 2016

대중교통을 포함한 연구들에서 사회적 효용 증진은 대중교통서비스 개선 또는 승용차 이용 억제책을 통한 대중교통 수요증가에 의한 것으로 풀이된다. 하지만 지금까지 대중교통 수요증가는 통행수단의 통행량 변화를 통해 사회적 효용에 영향을 미치고 관찰될 뿐, 대중교통 차내 혼잡도는 고민의 대상이 아니었다. 본 연구는 혼잡통행료 시행으로 증진되는 사회적 효용과 변화되는 대중교통수단 차내 혼잡도를 관찰하고 원인을 규명한다. 본 연구에서 혼잡통행료 시행은 대중교통수단 차내 혼잡도를 증가시키고, 대중교통 전용차로가 없는 경우 대중교통수단 혼잡도는 더욱 심화된다. 주목할 점은 대중교통수단 차내 혼잡도가 도심보다 도심 외곽구역에서 더욱 악화되고, 최선의 혼잡통행료는 차내 혼잡도를 상대적으로 덜 악화시키면서 효용증진 임무를 완수한다. 이러한 결과는 통행자의 직주근접성 변화, 통행횟수 조절, 그리고 혼잡통행료 징수가 가져올 우발적인 왜곡효과 때문으로 해석된다.

• 유통과학연구
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• 제12권2호
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• pp.27-37
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• 2014

Purpose - As economic activities between different countries have rapidly spread in a world of free trade, it is inevitable that a large volume of cargo will be carried between countries. It is natural, then, that CO2 emissions and other environmental pollutions have followed, which exposes people and society to serious environmental problems and social costs, and so on. Therefore, the need to understand logistics is not only a matter of transportation but also an environmentally oriented matter. The purpose of this study is to look at some lessons and implications from the European case in terms of green logistics matters. Research design, data, and methodology - In order to look into this matter, first, it has to be established that some cargo transport volumes using different transportation modes have clearly declined because of previous economic recessions. Some transport policies produced by the European Union (EU) are based in a long history of struggling to cope with transport matters in European countries. In its recent transport policies, the EU has provided greener transportation alternatives, realizing that pollution matters affect the European transport market. This study tries to determine what policies the EU has implemented to deal with green logistics matters. This study concentrates in particular on the Marco Polo program in the EU. Results - This study found that the EU seems to consider these kinds of matters, that is, transport and the environment in the context of green logistics. The EU launched some policy instruments to solve this matter relatively earlier than other countries and reviewed them as necessary. In order to make these policy tools work, the EU provided PACT for combined transport, and then the Marco Polo I and II European transport white paper packages. These European policies deal with green logistics matters in two ways. First, some restrictions have been imposed, especially taxation, and so on. Transport subsidies are also powerful means of handling green logistics matters in Europe. Along with these two means of dealing with transport and the environment, the EU eventually targeted integration of different transport modes. Instead of employing only a single transport instrument mode to deliver the cargo to be carried, such as trucking, rail, ocean-going carrier, flight, or inland waterway transport, the EU has proposed that combining transport modes is the best alternative for transport and the environment. That is, the EU is pursuing the adoption of multimodalism as an answer to the green logistics challenge as it provides a more cost efficient and more productive means of transport. Conclusions - In conclusion, multimodal transport should be considered when applying green logistics, as it can provide an alternative way to achieve transport and environmental solutions together at the present time. Two methods can be used to encourage multimodal transport: restrictions and subsidies. These are the lessons and implications from European green logistics policies.

• 한국ITS학회 논문지
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• 제15권3호
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• pp.23-33
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• 2016

본 연구는 SUR모형을 활용하여 서울 거주자의 수단별 통행시간 비율에 대한 영향요인을 규명하였다. 영향요인은 가구원 및 가구의 특성, 존 특성 변수 등을 선정하였다. 통행수단은 기존의 18개 유형을 압축하여 도보, 개인통행수단, 버스, 지하철, 철도, 자전거 등 6개 수단으로 재 정의하였다. 분석 결과, 개인교통수단과 대중교통간의 뚜렷한 차이를 발견하였다. 우선 차량을 보유하고 운전면허가 있는 경우에는 개인통행수단을 이용하는 경향이 강한 것으로 나타났다. 이와 함께 대표적인 대중교통 수단인 버스와 지하철간의 상관관계를 파악할 수 있었다. 지하철 수단은 개인통행수단이 이용 가능한 통행자가 함께 이용하는 패턴을 보인 반면, 버스 수단은 개인통행수단 이용이 어려운 경우에 이용하는 경향을 보였다. 이러한 선호도는 향후 서울을 포함한 수도권의 대중교통 정책을 수립함에 있어 다양한 시사점을 제시할 수 있을 것으로 기대한다.

• 한국ITS학회 논문지
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• 제16권4호
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• pp.54-63
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• 2017

본 연구는 광역전철 활성화를 목표로 승용차 대비 경쟁력 평가를 위한 수단선택모형을 개발하였다. 연구대상 노선은 수도권의 경의선과 중앙선이며, 열차운행 구간은 두 노선을 연결하는 일산역부터 구리역까지 설정하였다. 수단선택모형은 잠재선호조사(SP) 자료를 이용한 개별행태모형이며, 교통수단선택의 경쟁구도는 승용차와 급행열차이다. 연구 결과, 수단선택모형이 적정한 수준으로 도출되었으며, 이를 이용하여 통행자의 시간가치와 탄력성 값이 나타내는 특성을 분석하였다. 분석결과 광역전철에서 급행열차를 운행할 경우에는 통행비용의 감소보다는 통행시간의 단축에 주안점을 두는 것이 더욱 효과적으로 나타났다. 또한 이 같은 측면에서 개별노선간의 직결운행을 확대하고 급행열차를 운행하여 환승시간과 차내시간을 줄여주는 정책 추진이 요구된다.

• 한국ITS학회 논문지
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• 제20권1호
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• pp.22-39
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• 2021

본 연구에서는 공유 전동킥보드가 운영되고 있는 1기·2기 신도시 지역주민을 대상으로 SP조사를 수행하여 광역교통수단의 접근통행과 생활권통행의 공유 전동킥보드를 고려한 수단선택모형을 추정하였다. 연구결과 두 모형에서 공통적으로 통행시간과 통행비용이 음의 계수를 가지는 것으로 나타났으며 접근통행은 통행시간에, 생활권통행은 통행비용에 보다 민감한 것으로 분석되었다. 개인속성 및 가구속성에 따른 공유 전동킥보드 이용선호도를 살펴보면 40세 이하, 자전거 소유, 주로 이용하는 수단이 대중교통인 경우 긍정적인 영향을 보인 반면, 가구 월소득 300만원 미만, 개인 승용차 보유는 이용선호도에 부정적인 영향을 미치는 것으로 나타났다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.461-464
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• 2011

Rail transport has been considered as an environmental-friendly transport mode compared with other transport modes such as ship, truck, and aircraft. However, rail industry can not avoid a duty of alleviating Greenhouse gases emission owing to the Korean government polices for green growth which is an economic paradigm that simultaneously pursues growth and environmental improvement. The purpose of this research is to develop a methodology of determining an economic speed of freight train to be green freight train by considering fuel cost, environmental cost, and time cost. In the methodology, we first define a cost function based on cost factors and then suggest an economic speed of freight train by deriving a property.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.2297-2302
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• 2010

The status and effectiveness of Bi-modal Tram is analyzed through the comparison of the transport effectiveness and operation cost between the public transportation systems (bus, light rail transit) considering the vehicle and operation characteristic of new transit system Bi-modal Tram. The standard operation schedule is established in consideration of the vehicle specification and operation characteristic of main public transportation modes, and then the annual average operation cost is estimated depending on the volume, speed, analysis length for respective public transportation mode. Through analyzing the operation cost and distribution characteristic of public transportation modes depending on the transport volume and travel speed, the operational efficiency suitable for the city is derived. It is concluded that the operational efficiency of Bi-modal Tram is superior to that of the bus and light rail transit on the aspect of travel volume and operation speed.

• 한국통신학회논문지
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• 제21권10호
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• pp.2687-2702
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• 1996

It is desirable that the implementation of next generation information infrastructure is the Integrated Network combining the satellite and the terrestrial network. The application of the ATM network being the dominant infrastrure of terrestrial network to the satellite network is being studied variously. Considering these concepts, this paper analyzes due to ATM transport via satellite, evaluates the degradation of QoS and proposes reliable method of ATM cell transport via satellite. Because ATM is investigated with the optical fiber which is almost error free characteristics, the practical application of ATM transport via satellite essentially need the channel coding(FEC:Forward Error Correction) to enhance BER performance. But using the FEC coding, satellite link has burst error characteristics which evoke severe performance degradation fo ATM QoS. Therefore in satellite link, we analyze burst error characteristics using experimental results of computer simulation. Then to compensate these characteristics, based on this analysis and HEC dual mode algorithm we propose various interleaver structures(Block interleaver, Intra interlever, and Inter-Intra interleaver) to improve cell transmission QoS. We execute performance evaluations of iterleaver structures by computer simulation.