• Journal of the Korea Safety Management & Science
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• v.17 no.1
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• pp.93-101
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• 2015

The demand from customers on better products and systems seems to be ever increasing. To meet the demand, the systems are becoming more and more complicated in terms of both scale and functionality, thereby requiring enormous effort in the development. One bright spot of this trend is that such effort has been the driving forces of the remarkable advancement in modern systems development. On the other hand, safety issues appear to be critical in many large-scale systems such as transportation and weapon systems including high-speed trains, airplanes, ships, missiles/rockets launchers, and so on. Such systems turn out to be prone to a variety of faults and thus the resultant failure can cause disastrous accidents. For the reason, they can be referred to as safety-critical systems. The systems failure can be attributed to either random or systemic factors (or sometimes both). The objective of this paper is on how to reduce potential systemic failure in safety critical systems. To do so, a proper system design is pursued to minimize the risk of systemic failure. A focus is placed on the fact that complex systems have a lot of complicated interfaces among the system elements. To effectively handle the sources of hazards at the complicated interfaces and resultant failure, a method is developed by utilizing a design structure matrix. As a case study, the developed method is applied in the design of train control systems.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.6
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• pp.169-181
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• 2017

As vehicle supply rate increases, traffic jam-related problems emerge and sharing transportation including carpool, centered on the advanced countries, becomes a major interest. This study aims to analyze benefit generated by carpool during the rush hours of medium and long distance travel, focused on the workers of public Agencies relocated to innovation cities. In order to compute benefit, carpool demand of relocated public Agencies was estimated and travel speed was estimated according to reduced traffic volume through carpool adoption using a traffic flow model. The benefit were computed dividing them into direct benefit and indirect benefit. As a result, 23billion KRW and 56.5billion KRW were annually revealed to be generated in terms of direct benefit and indirect benefit. The study result is expected to be used as part of basic research to adopt carpool for future traffic demand management.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.5
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• pp.462-472
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• 2017

Sunken vessels on major fairways can cause many problems in terms of maritime safety and the marine environment. In order to prevent secondary marine pollution accidents caused by sunken vessels, information on sunken vessels has been collected, a risk assessment has been conducted, and the relevant vessels are being managed according to the results of each assessment. However, there is still a demand for improvements. The most important of the improvement plans is a paradigm shift. In other words, the management of sunken vessels needs to be transformed according to a new paradigm to manage all sunken vessels within three years from the time of sinking. Legislative improvements are also needed for the reporting system for sunken vessels, risk assessment tools, the implementation of risk mitigation measures, and criteria for the implementation cost of risk mitigation measures. In addition, close coordination between marine pollution response and sunken vessel management efforts is needed. As the division of duties between the Korea Coast Guard and the Ministry of Oceans and Fisheries is vague, collaboration between the two ministries is required. Close collaboration is also needed between the departments of navigation safety management and sunken vessel management. Therefore, it is necessary to more clearly establish the relationship between the two systems and create a synergy effect between the two administrative operations using the results of the risk assessment in the Marine Environment Management Act to determine the navigational risk posed by obstacles with regard to the Maritime Safety Act.

• Journal of Korean Society of Transportation
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• v.30 no.3
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• pp.95-106
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• 2012

The railway service in the Seoul metropolitan area is facing variety of l changes such as extension of service coverage, new construction, and introduction of express service which in turn causes changes on demands. The demand affects train operation characteristics (frequency of service, train formation) as well as on the congestion rate which is one of the major evaluation index in metropolitan area user service. For the efficient operation of the train, the relationship among the minimization of fleet number, operating cost, and service level has been analyzed. Using the Powersim, which is a system dynamics (System Dynamics) simulation program for realizing optimized simulation for train-formation, this paper identified that some stations of Gyeong-bu line exceeded limit congestion rate(150%) of a fleet already that means it is best to maintain current condition of the line; however, the Gyeong-in line and the Gwa-chon line showed no excess of the limit congestion rate so that it is possible to reduce 2-4 fleets of train for efficient operation. In addition, in case of Jang-hang line between Cheon-an and Sin-chang, a train consisting of 10 fleets provides services which is same formation of train for Gyeong-bu line. This study proved that the congestion rate will not rise greatly with only 4 fleets of a train for the service in Jang-hang line, and it is considered that a study for shuttle service between Cheon-an and Sin-chang is necessary.

• Journal of the Korean Society for Railway
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• v.19 no.6
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• pp.833-843
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• 2016

Recently, in the field of rail freight transportation, the number of trains dedicated for shippers has been increasing. These dedicated trains, which run on the basis of a contract with shippers, had been restricted to the transportation of containers, or so called block trains. Nowadays, such commodities have extended to cement, hard coal, etc. Most full freight cars are transported by dedicated trains. But, for empty car distribution, the efficiency still remains questionable because the distribution plan is manually developed by dispatchers. In this study, we investigated distribution models delineated in the KTOCS system which was developed by KORAIL as well as mathematical models considered in the state-of-the-art. The models are based on optimization models, especially the network flow model. Here we suggest a new optimization model with a framework of the column generation approach. The master problem can be formulated into a transportation problem with additional constraints. The master problem is improved by adding a new edge between the supply node and the demand node; this edge can be found using a simple shorted path in the time-space network. Finally, we applied our algorithm to the Korean freight train network and were able to find the total number of empty car kilometers decreased.

• Journal of Fisheries and Marine Sciences Education
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• v.13 no.1
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• pp.1-18
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• 2001

The purpose of this research was to develop curricula for the department of marine products marketing in fisheries high schools. The specific objectives were as follows; 1) To investigate the demand of students, teachers in fisheries high schools, and workers in marine products marketing for the educational program. 2) To analyze the jobs of the marine products marketing fields. 3) To develop curricula for the department of marine products marketing on the basis of the theoretical background and the result of the objective 1) and 2). In order to achieve these objectives, domestic and foreign literatures, research reports, and theses were referred to in order to know the academic classification of fisheries economics and curricula of junior colleges and universities were collected and analyzed. To achieve the first objective, the degree of the students' knowledge of marine products marketing through fisheries management textbook was investigated. And the questionnaire survey of the demand was conducted on the subject of professors at the departments of fisheries management, teachers in the charge of the related courses and those who work for marine products marketing-related firms. The questionnaire was composed of 22 items about the knowledge of marine products marketing and 27 items about the job capacity. To achieve the second objective, the occupations were surveyed on the subjects of the works who work for marine products marketing. They were sampled randomly among the marine products buyers, wholesalers, auctioneers and salespersons. The results of this research were as follows; Taking grades and credits at each subject were made out on the consultation of the experts in marine products marketing. The curriculum of the professional subjects related to marine products marketing in fisheries high schools is suggested as follows; General Fisheries(10th grade, 6 credits, curricular discretionary class), General Oceanography(10th grade, 4 credits, curricular discretionary class), Fisheries Marine Transportation Information(11th grade, 8-12 credits), Marine Products Marketing(11th grade, 8-12 credits), Fishery Sale and Management(11th grade, 8-12 credits), General Fisheries Management(11th grade, 6-8 credits), Accounting Principle(11th grade, 4-6 credits), Marine Products Processing(12th grade, 4-8 credits), Commercial Law(12th grade, 4-6 credits), Management Practice(12th grade, 4-6 credits), Computer Practical Business(12th grade, 4-6 credits), Marketing(12th grade, 4-8 credits), General Marketing Management(12th grade, 6-8 credits), Marketing Information Practical Business(12th grade, 4-6 credits) Marketing Management I(12th grade, 4-6 credits), Marketing Management II(12th grade, 4-6 credits). If this curriculum is adopted, it will meet the demands of the educational aims and the industrial society.

• Journal of the Korea Safety Management & Science
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• v.10 no.2
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• pp.163-168
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• 2008

These days, international air-logistics demand is getting bigger and bigger by increasing in trading volumes of export and import of Asia. It makes the air logistics of stakeholder to invest in air logistics facilities and information systems for meeting the growth of air transportation. However there are some problems that the efficiency of investment is not good by duplicately investing in information systems and moreover not compatible with each other because the stakeholder is investing in individual information system and air logistics facilities instead of constructing the integrated infrastructure. In this paper, we investigated the export, import, and transshipment process of air logistics to simplify air logistics process through the RFID(Radio Frequency Identification) application and the 4PL system.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2006.05a
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• pp.1754-1757
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• 2006

Recently many firms operate a cross-docking center in addition to run a distribution center to reduce logistics costs and maintain or enhance logistics service. However, it is true that many firms just operate their cross-docking centers as they are without any change, in spite of that the location of the cross-docking center should be changed and operated when the location of distribution center is changed and moved. This study presents the method that re-selects the location of the cross-docking center when the existing distribution center is changed. Describing the operation environment to apply the cross-docking system and the selection criteria of the cross-docking center under the environment of changeable logistics network, we define the simulation model which can analyze and select the location of the cross-docking center applied to a logistics field. The simulation model presents experiential algorithm selecting the location with the data of the demand point such as volume, transportation costs, and delivery distance.

• The Korean Journal of Health Service Management
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• v.11 no.4
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• pp.189-202
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• 2017

Objectives : This study aims to present a new classification system using evaluation standards to ensure the safety of transport ventilators used in Korea. Due to the rapid advancement of technology, various types of ventilators have been developed and as the range of application increases, so does demand. With quick access to information and a growing economy, the technology used in Korean hospitals is equivalent to that of other countries; however, regulatory and safety consciousness are still lagging in Korea. Methods : Based on researching overseas cases, reference data and standards for improving the current system in Korea are proposed. Results : According to the review of transport ventilator use in Korea, it was found that concerns about safety is due to the absence of a standardized classification system for evaluating the safety and effectiveness of transport ventilators. Conclusions : In order to improve the safety of patients and the quality of medical care, it is essential to establish guidelines and assessment standards guaranteeing the safety of transport ventilators in Korea. Clear definitions and classifications for devices must precede the application of such standards. In addition, effective evaluation standards should be developed in order to resolve problems and improve upon the current system through continuous validation.

• Proceedings of the Safety Management and Science Conference
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• 2006.11a
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• pp.373-383
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• 2006

Logistics is one of the most important factors to manage a stream of materials in economic environment. Establishing effective logistics system needs to consider some constraints which are fluctuation of materials volume, a long distance between makers and consumers, one way logistics and small quantity batch production. It is estimated that Unit Load System should be a powerful method to cope with those problems. It helps to realize the key issues which are Standardization and Logistics Pool System The Material Unification of Logistics System is able to participate in all kinds of industries including manufacturing, distribution and logistics. This system has some merits which are a long distance transportation cost down, product recovery, and treatment in the unbalance of demand and supply caused by unstable materials volume. Four strategies of Material Logistics Model are Packing Rationalization, Logistics Pool System, JIT System application and establishing effective infrastructure. The Material Unification Of Logistics System based on Unit Load System achieves efficiency of logistics and largely decreases moving cost.