• Journal of Energy Engineering
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• v.10 no.3
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• pp.233-242
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• 2001

This paper attempts to analyze the effects of promotion of natural gas vehicles (NGVs) on LNG storage facilities and load patterns, and to verify economic feasibilities of NGVs as a DSM (Demand-Side Management) strategy. For these purpose, we have established an econometric mode. Results from the model indicate that natural gas demand in transportation sector will increase continuously, having a 7.84% share in total natural gas demand in 2014. By this analysis, the increased use of NGVs can result in a decreased requirement on the volume of around 1.3 LNG tanks lower in 2014. Also, it shows that TDRs can be reduced by 0.4 for the city gas and by 0.15 for the total LNG in 2014. As a conclusion, we suggest that the promotion of NGVs may play an efficient role as a DSM strategy, and should be considered as a promising strategy to optimize the investment needs in LNG sector as well as an environmental protection measures. Lastly, we acknowledge that a transportation module in our model is based on a Korean government's NGVs promotion plan, not on a market function.

• Journal of the Korea Safety Management & Science
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• v.16 no.3
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• pp.369-376
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• 2014

The national Logistics Information system has been rapidly developed on account of the dramatic improvements in the military's logistics support system and supply support system, making a transition from manual work system to computerized work system. Supply level, however, does not reflect these changes in the overall logistics environment and still retains the state it was in the 1970s. This research uses the accumulated data from the equipment maintenance information system developed in the year 2009 to analyze RWT(Requisition Wait Time) and CWT (Customer Wait Time). The analysis estimated the realistic transportation and ordering time and led to the conclusion that the differentiated ASL operation system that considers demand level should be adopted instead of the uniform ASL employment system.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.397-407
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• 2010

The Railroad that is representative transportation of Low Coal and Green Growth is industry that meet and serve unspecificness many customer unexpensive price as industry doing against as social overhead capital. Present our country railroad achievement is real condition that is not coming out in eternal in the red management. Accordingly, In this research, analyze success factor of management black-ink balance of railroad advanced nation such as Japan, France and Compare with our country and grasps problem of present city railroad fare system. Finally, alleviate fare burden of customer through diversification of fare system service such as establishing point uniformly for railroad fare that introduce first in Japan JR Kyushu railroad and propose the improvement of management of railway operation organization through demand enlargement.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.31 no.1
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• pp.99-106
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• 2023

글로벌 팬데믹 사태는 항공 수요에 부정적인 영향을 끼치는 요소 중 하나다. 글로벌 팬데믹으로 인해 한국은 2020년과 2021년의 항공 승객 수가 2019년 대비 각각 68.1%와 47% 감소했다. 본 연구는 지난 20여년 동안 발생한 4대 팬데믹 특성을 분석, 전염병의 영향을 연구하는 것을 목표로 한다. SARS, H1N1, MERS 및 COVID-19의 발생기간 동안 한국의 항공 여객 및 화물 수요에 대한 실증 데이터를 활용하여 영향력을 분석한다. 또한 머신러닝 회귀 모델을 구축하여 향후 발생할 다른 전염병 대한 항공 수요를 예측하고자 한다. 연구 결과, 전염병이 항공 운항편수와 승객에 부정적인 영향을 미친다는 사실을 발견하였다. 반면화물 수송에는 긍정적인 영향을 미친다는 분석 결과를 도출하였다. 본 분석에 활용되는 회귀 모델은 팬데믹 기간 동안 항공수요를 예측하는 데 평균 86.8%의 기능을 보였다. 또한 본 연구는 특정 국가의 팬데믹 상황보다 전 세계적인 팬데믹 상황이 항공 운송 수요에 더 많은 영향을 미친다는 것을 보여준다.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.614-620
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• 2011

Railway intelligent transportation systems and related Ministry of Land and rail operating agency's railway informatization planning of information technology, effective through the use of management strategies to establish or run to support the systematic informatization investment that you want to execute work in progress, during and yet the institutional informatization of operations mainly in the form of efficiency is Chinhae. Accordingly, in order to promote the details of the final challenge of providing real-time information and the usefulness of this information collection is clearly for the railway sector by function of the components is necessary to distinguish. In this paper, the details of the plan goals, promoting convenient rail-based real-time information, to promote optimal gohyoeuleul railways, railway safety and comfort, was defined as three. Selection of each goal, because the direction of vision and ITS around the railroad center of road users by highlighting the benefits of the railroad's traffic information center user switching, real-time delivery of information diversity (enhanced content) that can increase the capacity of line train operating systems, enhancing the safety management system introduced in the monitoring system and is a railroad crossing. Because urban railway project in accordance with the goal of decreasing the annual rate of the train support, and the average passenger wait time savings, increased future demand for railway, rail safety, including securing the expected effects may occur.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.14 no.2
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• pp.45-55
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• 2006

Air transportation industry becomes more competitive because that the restrictions on new access to market were eased and related enough for each airline to choose the freight rate and the route without rein. New competitors are pursuing convergence strategy which focuses on low freight rate as a niche strategy for increasing market share by stimulating low cost demand. This strategy is now spreading all over the world such places as Europe, Asia, Oceania and etc. As of December 1, 2004, hundreds of low cost carriers are participating actively in the market and finding their level as a new strategic group in the air transportation industry with expanding their market. In case of USA, however, many airlines, which had newly entered to the market, went into bankruptcy in the mid-1980s. People Express in USA established in 1980 is one of the examples of failure. In case of Japan, Hokkaido International Airline, a typical low cost carrier which established in 1997, filed for bankruptcy. This study is for examining the strategic implication closely through the study on management strategy and cases of failure of low cost carriers.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.36 no.1
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• pp.8-16
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• 2013

We consider a problem of presort and loading of commercial bulk mails in a mailing service. Here, presort is the process by which a mailer prepares mail so that it is sorted to at least the finest extent required by the mailing service provider for the (discounted) price claimed. The problem is formulated as a special type of transportation problem. To solve industrial-sized problems, we develop an efficient heuristic algorithm and perform experimental tests on randomly generated problem instances. Results of the tests show that mailers can save mailing cost much more when they use small-sized mail trays with less frequent mailings. Also, large-sized mailers can obtain much more cost saving than small-sized mailers. In addition, cost saving effect is influenced by delivery area distribution of mails and fluctuation of mailing demand.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.872-880
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• 2011

In terms of accessibility and time the tram rail and bus transportation system is equipped with all the benefits of. In addition, construction and operating costs than light rail trams reduce AGT, and by car from the city center by inhibiting the transport demand management, pedestrian-oriented transportation system, including city jaebuheung can expect several effects, depending on the expected introduction of trams are. Accordingly, increasing interest in streetcars and trams, and the forum is running and the green at the National Assembly, Korea Railroad Research Institute samurai tram lines in the Korean research team developed the tram is thriving. In this study, in Korea as a way to introduce a tram tram to enhance the safety and reliability challenges for the advancement and promotion of foreign tram with the safety regulations and accident cases learn safety measures to strengthen the domestic transportation. The expected introduction of the tram fits the matter at issue and the perception of citizens and the passengers can make changes to present policies, the successful national introduction of trams and safety study aims to review.

• Management Science and Financial Engineering
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• v.14 no.2
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• pp.45-66
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• 2008

Refuse collection, one of important elements in reverse logistics, is an activity rendering recyclables or wastes and moving them to some points where further treatment is required. Among various decisions in the collection activity, we focus on network design, which is the problem of locating collection points as well as allocating refuses at demand points to collection points while satisfying the capacity restriction at each collection point. Here, the collection point is the place where recyclables or wastes near the point are gathered, and locating the collection points is done by selecting them from a given set of potential sites. The objective is to minimize the sum of fixed costs to open collection points and transportation costs to move refuses from demand points to collection points. An integer programming model is developed to represent the problem mathematically and due to the complexity of the problem, two types of heuristics, one with simultaneous and the others with separate location and allocation, are suggested. Computational experiments were done on test problems up to 500 potential sites, and the results are reported. In particular, some heuristics gave near optimal solutions for small-size test problems, i.e., 2% gaps in average from the optimal solution values.

• Land and Housing Review
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• v.2 no.3
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• pp.217-226
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• 2011

The Seoul Metropolitan Government is striving to minimize the amount of traffic according to the supply of apartment houses along with the solution of housing shortage for the low income people through high density development near the subway area. Therefore, a stronger policy is necessary to control the traffic of the passenger cars in a subway area for the successful high density development focusing on public transportation, and especially, the estimation of the demand of cars with high reliability is necessary to control the demand of parking such as the limited supply of parking lot. Accordingly, this study developed car ownership forecasting model using Look-up Table among category analyses which are easy to be applied and have high reliability. The estimation method using Look-up-Table is possible to be applied to both measurable and immeasurable types, easy to accumulate data, and features the flexible responding depending on the changes of conditions. This study established Look-up-Table model through the survey of geographical location, the scale of housing, the accessible distance to a subway station and to a bus station, the number of bus routes, and the number of car owned with data regarding 242 blocks in Seoul City as subjects.