• Journal of the Korea Society for Simulation
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• 제8권3호
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• pp.91-103
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• 1999

This paper proposes an algorithm which reduces transportation cost while goods are delivered in time in a logistics system. The logistics system assumed in this paper is the system in which multiple cars moves various goods from spatially distributed warehouses to stores. For reducing transportation cost, the car assignment algorithm which allocates goods to minimal cars employs the BF method; routing of each car is modelled as the TSP and is solved by using the genetic algorithm. For evaluating the proposed algorithm, the logistics system is modelled and simulated by using the DEVS formalism. The DEVS formalism specifies discrete event systems in a hierarchical, modular manner. During simulation, each car is modelled as a message and traverses warehouse and stores. When a car arrives at a warehouse or a store, predetermined amount of goods are loaded or unloaded. The arrival time and departure time of cars are analyzed and eventually whether goods are delivered in the desired time bound is verified.

• Journal of Korean Society of Transportation
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• 제33권4호
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• pp.368-378
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• 2015

This study aims to analyse the differences of job satisfaction in road freight transportation industry workers by different types of employment. The researchers utilized reliability test and factor analysis to estimate the validity and feasibility of the questionnaire. Multivariate analysis of variance (MANOVA) was also applied to assess the differences of job satisfaction level by different employment types. The results of reliability test and factor analysis clearly show that questionnaire samples are reliable and feasible. The multivariate analysis of variance result shows statistical insignificance in the level of job satisfaction between part-time workers and special type ones. On the other hand, there was a significant difference between full-time workers and those in other types of employment. The significant variables such as income, welfare, and working hour, etc were discovered.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 한국항해항만학회 2018년도 추계학술대회
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• pp.239-240
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• 2018

In order to improve the productivity and continuous competitiveness of container terminals, it is necessary to make efforts to reduce operational losses at each terminal. As a study on this, it is necessary to study the non-productivity movement based on the shuffle(re-handling) in the yard analysis is needed. In this study, non - productive activity factors were classified by prefecture, transporter, shippers and terminal based on operation data of domestic A terminal. As a result, 14.7% is due to the causes of shipping companies and shipping companies, and in addition, 85.3% of the respondents indicated that they were responsible for the terminal operation. In order to minimize the above factors, it is necessary to reduce the non-productive activity through rapid information processing and pre-information acquisition from shipping companies, and minimize the influence of bulge-out through installation of concrete blocks in the equipment field.

• Proceedings of the KSR Conference
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.453-460
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• 2011

The inland logistics center is a large scale of logistics facility that enables roads, rails, ports, and airports to carry out chained-transports and combined-transports, and the logistics center are established at the main logistics posts in order to reduce the cost of transport by mass transportation. However, it is expected that the capacity of Euiwang ICD, the only inland logistics centers in the capital area, will reach its limit before 2015, so it is required to establish another stations or to improve the existing facility. Especially, in case of Euiwang ICD, the expansion of the center is not possible because of its position, so it is required to establish new logistics centers in other places in order to raise the capacity of transport. Therefore, this study suggests to establish new metropolitan logistics centers on the western coast line in order to solve the problem of shortage of tract capacity that is brought on by the newly established inland logistics centers on the axis of the western coastline (Song-san Station and An-jung Station), and analyzes how the new logistics center will distribute railroad cargoes. By these, this study contributes to reduce the cost of transport by providing smooth railroad transport service.

• Journal of Navigation and Port Research
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• 제40권3호
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• pp.121-128
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• 2016

The present study aimed to derive decision factors for residency in the hinterland of Incheon New Port that is undergoing the development of port hinterlands and changes in leasing methods considered from the perspective of companies and analyze the priorities of determinants for residency through Fuzzy-AHP in order to present a direction to activate companies entries into the hinterland of Incheon New Port. When the comprehensive rankings of determinants for residency in the hinterland of Incheon New Port, rent levels among cost factors took the highest ranking with a value of 10.2% followed by the throughput of the port among market factors with a value of 8.2%, the scale of the market on the background with a value of 7.3%,, reduction in inland transport costs among cost factors with a value of 7.1%, connectivity to inland transportation networks among locational factors with a value of 6.7%, and designation as a free trade zone and the scale with a value of 6.4%. When seen from the viewpoint of companies to determine whether to move into the hinterland of Incheon New Port, the rent level should be provided to be more attractive compared to the hinterlands of ports in other regions. In addition, inland transportation costs which are a matter of the most serious concern of shippers in the capital region should be reduced and sea routes that can directly connect Incheon New Port to US ports and European ports should be opened.

• The Korean Journal of Air & Space Law and Policy
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• 제31권2호
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• pp.177-214
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• 2016

During more than 20 years of practice, Civil Aviation Law has experienced three times of amendments since it was enacted in 1995. But these revisions are limited to the technical level. The problems and limitations have become increasingly prominent in its implementation. Firstly, the civil aviation law is the result of interests game among several departments and some legal issues was left behind and the regulation was very vague as a result. Secondly, the process of aviation legislation is the process that the country has undergone profound changes and social transformation. The 20 years is long enough for the society to undergo tremendous changes and 1995 version of civil aviation law does not keep pace of development of economy. There was a serious lag between reality and the law. In order to actively promote the development of the aviation industry and overcome implementation issues of the Civil Aviation Law, Civil Aviation Administration of China (CAAC) initiated modification procedure the law and published new draft of Civil Aviation Law in August 2016. The spirit of this modification is to learn and absorb new achievements of domestic and foreign legislation and the International Convention on civil aviation. Furthermore, the purpose of the revision is to provide favorable policy for the development of civil aviation industry and improve aviation safety and supervision, strengthen and protection of consumer rights and interests, to enhance the safety of civil aviation activities, and promote the development of general aviation. This revision concerned to the 78 articles which are revised or deleted and 24 articles added. The highlights of the draft include but not limited to the enhancement of security management, clarification of the main responsibility for production safety. And also it added the provisions related to the construction of effective tracking capability of public air transport enterprises and license system on the transport of dangerous goods. Compared with the existing civil aviation law, the draft has made a great improvements. But there are several deficiencies and limitations in the drafts. These problems need to be supplemented and perfected through further amendments in near future.

• Proceedings of the Korean Vacuum Society Conference
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.61.1-61.1
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• 2013

최근 지구온난화 및 원유 공급 감소 또는 고갈로 에너지 효율성 높고 저탄소 녹색성장을 주도할 수 있는 철도산업에 대한 관심이 고조되고 있다. 초고속 자기부상철도는 에너지 효율이 높은 경제적인 교통수단으로써, 단위 수송당(인-km) 온실가스 배출량이 자동차의 38%, 항공기의 17%에 불과하고, 같은 궤도운송시스템인 고속철도에 비해서도 77%에 불과하고 단위수송당 에너지 소비율이 항공기의 80% 수준에 불과하므로, 화석에너지의 고갈이 예상되는 미래에 장거리 고속 이동 수단으로써 중요성이 확대되고 있다. 또한, 비접촉 추진 방식이므로 바퀴 접촉식 고속철도에 비해서 유지보수 비용이 저렴하고(34%에 불과) 고속철도에 비해 10dB 이상 소음 발생이 적은 수명주기 비용 및 환경측면에서 기존 철도시스템에 비해서 경쟁력이 있으므로 시급한 개발과 활용이 요구되고 있다. 본 연구에서는 초고속 자기부상철도 연구와 관련된 국내외 연구동향과 함께, 국가연구개발사업으로 추진중인 초고속 자기부상철도 핵심기술개발사업에 대해 살펴보았다. 또한, 미래기술로 각광을 받고 있는 튜브트레인 기술에 대해서도 알아보았다.

• Journal of Korean Society of Transportation
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• 제24권2호
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• pp.53-63
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• 2006

The objective of this study is to estimate Korean transportation service index (KTSI), and to explore possible uses of the KTSI. The KTSI was monthly index to represent the level of passenger and freight services by road, railroad, air and maritime modes, which was developed from eight series. Four of these series measure the level of passenger services (passenger-kilometers) by road, railroad. air and maritime modes : monthly data from January 1995 to December 2004. Similarly. the remaining four series measure the level or freight activity (tonnage) by four modes during the same period. Given the weights of modal revenues, component series were aggregated into two indexes (passenger index and freight index) and a composite index using Chained Fisher Ideal index. which was a geometric mean of the Laspeyres index and the Passche index. The Fisher Ideal index is one of the 'superlative' indexes, which diminish 'substitution bias' as current-weighted indexes. As a result, the freight index and the composite index explain economic conditions better than the passenger index. Based on the composite index. the newly estimated KTSI shows an average lag time of one and a half years at peaks and three months at troughs in comparison with domestic business cycles. Nonetheless. the following efforts are needed for more credible and useful estimates; establishment of data collection scheme in time. credibility uplift of used data, development of various indexation methods.

• Journal of the Korea Society for Simulation
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• 제24권1호
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• pp.35-43
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• 2015

This research proposed a new method to evaluate the objective validity to launch smart transportation services that various stakeholders are complicatedly inter-connected. First of all, we have designed the fundamental business model to form the smart transportation services and defined the stakeholders taking part in the services. Also, the criteria to evaluate the economical validity has been proposed based on the relationship among stakeholders. Especially, in the case EV drivers and charging service providers, the economical validity depends on the scale of spreading. Therefore, we have compared the two extreme scenarios, the poor and stable level of EV spreading. According to the result, it may be said that EV drivers and charging service providers cannot be guaranteed the economical validity due to the burden of initial investment. On the contrary to this, suppliers of EV and charging gears may secure more than a certain level of profit. In addition, the government may have great profit due to reducing the CO2 emission and cost for importing energy sources. Therefore, it is needed to enhance the level of supporting EV drivers and charging service providers at the first stage. Also, the impact of the ratio of EV and charging service stations on the economical validity of smart transportation should be further investigated.

• The Journal of the Convergence on Culture Technology
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• 제6권2호
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• pp.191-197
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• 2020

As an effective means of price discrimination, some suppliers offer trade credit to the distributors for the purpose of increasing the demand of the product they produce. The availability of the delay in payments from the supplier enables discount of the distributor's selling price from a wider range of the price option in anticipation of increased customer's demand. In this regard, we consider the problem of determining the distributor's optimal price and lot size simultaneously when the supplier permits delay in payments for an order of a product whose demand rate is represented by a constant price elasticity function. It is assumed that the distributor pays the shipping cost for the order and hence, the distributor's ordering cost consists of a fixed ordering cost and the shipping cost that depend on the order quantity. For the analysis, it is also assumed that inventory is depleted not only by customer's demand but also by decay. We are able to develop a solution algorithm from the properties of the mathematical model. A numerical example is presented to illustrate the algorithm developed.