• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.05a
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• pp.1036-1041
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• 2006

본 연구에서는 허브와 스포크의 입지선정과 차량 경로가 통합된 hub-and-spoke 네트워크 설계문제를 다룬다. Hub-and-spoke 네트워크는 대량화와 공동화를 통해 물류효율화를 실현하기 위한 대표적인 구조로 물류시스템에서 흔히 사용되고 있다. 이러한 물류시스템에서 물류비용의 절감과 고객서비스 향상을 위한 효율적인 수송네트워크 설계는 매우 중요하다. 전통적인 hub-and-spoke 네트워크 설계문제에서 각 스포크의 위치와 화물량이 미리 주어진 상황에서 허브의 입지를 결정하였다. 하지만 스포크 역시 스포크가 담당하는 고객들의 위치와 담당 영역에 따라 그 위치와 수, 그리고 화물량이 변할 수 있다. 또한 정확한 비용산출을 위해서는 스포크에서 고객으로의 수집과 배달을 위한 차량경로가 함께 고려되어야 한다. 다루는 수송망 설계문제는 상호 관련성 있는 여러 부분문제가 결합된 통합문제로써 이를 해결하는 방법으로 기존의 발견적 방법에 의한 순차적 기법은 한계가 있다. 본 연구에서는 공생 진화알고리듬 기반의 방법론을 채용하여 다루는 수송망 설계문제를 동시에 통합적으로 해결할 수 있는 알고리듬을 개발한다. 실험을 통해 개발한 알고리듬의 우수성과 그 적용성을 보인다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.10
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• pp.1315-1321
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• 2011

Prior to the experimental and production stages of goods, the strengths should be evaluated in the design stage. The introduction of commercial codes at the design stage gives benefits such as cost and time economies in the production and strength evaluation. In this study, structural analysis and fatigue analysis are carried out using ANSYS modeling of the 3D geometry of the wheel. In a comparison of dish-type and spoke-type wheels, it is shown that the deformation and maximum equivalent stress for the dish-type wheels are lower than those for spoke-type wheels. Nevertheless, spoke-type wheels are often used because they are light and have exhibit excellent cooling performance. Furthermore, according to the results of life analysis, aluminum wheels show improved resistance to fatigue compared to steel wheels.

• The Korea Swine Journal
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• v.6 no.6 s.58
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• pp.94-96
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• 1984

• Hwankyungkyoyuk
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• v.4 no.1
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• pp.36-47
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• 1993

• Journal of Korean Society of Transportation
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• v.26 no.5
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• pp.117-127
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• 2008

After the deregulation of the aviation market in the United States in 1978, airlines took advantage of the possibilities of the liberalized market and reorganized their networks. Then, the hub-and-spoke networks became widely used in the aviation market. The framework of hub-and-spoke network made it feasible to amplify flight networks. Thus, a number of airlines were able to fly to more destinations than ever before through the networks. Amplification of networks can be implementing through the transfer of passengers, transshipment of cargo, or both most researches have been concentrated on the passenger aspect at airports worldwide. Air cargo, however, has become one of the most significant areas at hub airports to keep their leading position in terms of the provision of services and handling volumes. This paper investigates the connectivity of airfreight networks as the temporal concentrations in current network at Incheon International Airport. In order to evaluate airline flight schedule effects to stimulate hubbing at an airport, the indirect connectivity can be considered to be the number of direct frequencies, the minimum connecting times and the quality of the connection determine indirect connectivity. Therefore the connectivity of freight transshipment depends on both the quality of the connection at the hub airport and the quality of the indirect flight compared to the direct flight. In addressing these issues, this paper analyzes the connectivity of flight schedules using a temporal wave-system structure and estimates the degree of connectivity and quality of connectivity applying the NETSCAN model.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.561-562
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• 2012

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2007.06a
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• pp.547-548
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• 2007

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.11a
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• pp.233-234
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• 2010

• Journal of Korean Society of Transportation
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• v.27 no.4
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• pp.195-206
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• 2009

The deregulation of aviation markets in Europe and the United Sates had led airlines to reconfigure their networks into hub-and-spoke systems. Recent trends of "Open Skies" in the Asian aviation market are also expected to prompt the reformation of airlines' networks in the region. A significant connectivity index is a crucial tool for airlines and airport authorities to estimate the degree of hub-and-spoke operations. Therefore, this paper suggests a new index, Continuous Indirect Connectivity Index (CICI), for measuring the coordination of airlines' flight schedules, applying it to the Asian, European and the American aviation markets. CICI consists of three components：(i) temporal connectivity to identify the attractiveness between connection flights, (ii) spatial connectivity to differentiate the attractiveness by de-routing distance with continuous linear function, and (iii) relative intensity to reflect the effect of direct flight frequency on transfer routes. CICI is evaluated to examine a casual relationship through regression analyses with two dependent variables of the number of transfer passengers and transfer rates. Compared with Danesi's index and Doganis' index through evaluation processes, CICI has a higher coefficient value of determination, implying that it explains the relationship between connectivity and transfer passengers more precisely.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.10a
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• pp.148-148
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• 2009

알루미늄휠의 크롬도금은 휠의 복잡한 형상 때문에 고전류 부분인 스포크에 비해 저전류 부분인 윈도우는 도금의 두께가 얇아 부식이 발생할 가능성이 높아 도금두께를 향상시키기 위하여 보조양극을 설계, 개발하였으며 고전류와 저전류의 도금두께 편차를 줄이고 균일도금의 가능성을 확인하고 캐스시험을 통해 내식성이 향상됨을 알 수 있었다.