• Journal of the Korean Society of Industry Convergence
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• v.22 no.5
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• pp.529-536
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• 2019

Recently, various efforts have been tried in the construction industry to improve productivity by applying the fourth industrial revolution technology. Among the various technologies, researches for the automation and digitization of earthworks are being carried out steadily. As the interest in the benefits of digitalization of the earthwork field has increased, there have been more cases of technology development and application for digitalization of the earthwork field. However, there is not enough case study to present the analysis results of application cases. The purpose of this study is to verify the feasibility of applying the digitization technology of the earthwork in actual worksite. In order to digitize the worksite terrain, it is required the process of field measurement, measurement data registration, earthwork information input, and analysis cell generation. Particularly, it is possible to achieve information-enabled digitization rather than digitalizing only the shape through the input of the earthwork information and the analysis cell generation. By using the digital information of the earthwork field, it is possible to visually recognize the change of the earthwork field, so that it is expected to enhance the worker 's understanding and to be highly applicable to the management work. It is expected that the digital technology of earthwork site will be able to know the precise amount of volume change of the earthwork numerically, and it will be highly applicable to construction management.

• Journal of Korea Port Economic Association
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• v.24 no.2
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• pp.193-208
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• 2008

This study aims to analyse the ripple effect of Physical distribution service industry on national economy using input-output tables and present the results as data for political plans in this field. For the analysis, it uses input-output tables developed and published by Sank of Korea in 1998, 2000, and 2003. To sum up the results, production inducement effects are 1757 for railroad transport, 1688 for road transport and 1617 for loading. Import inducement effects of assistant services, loading, storage, warehouse and other transport-related services are low while the effects of water and air transport are high as follows: 0.679 and 0.558 respectively. Then, added-value inducement effects are presented as follows: 0.841 for railway transport, 0.828 for road transport, 0.962 for transport assistant service, 0.939 for loading, 0.938 for storage and warehouse, and 0.942 for other transport-related services. Sensitivity dispersion index of road transport is high while that of water transport, storage and warehouse is low. And influence coefficient of railway and road transport is high while that of water and air transport is low. In respect to the employment structure of Physical distribution service industry, 744,000 are employed for road transport industry, which is the largest number, 19,000 for air transport and 20,000 for assistant services, which is the least number.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.39 no.5
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• pp.657-665
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• 2019

The domestic railway parts and equipment manufacturing industry is mainly focused on SMEs, and the majority of them are suffering from profitability because they cannot build economies of scale. Besides, they have survived in the form of importing technology products from overseas advanced countries and delivering them to domestic railway operators rather than having in-house technology. Therefore it is necessary to study whether the problems of the current railway industry can be identified and improved and at the same time, whether the government's railway industry development policy is properly reflected. literature studies related to technology commercialization, and conduct surveys of AHP questionnaires on the experts of the manufacturing industry of SMEs, academics / research institutes of the railway industry. After that, the Level 3 activation method AHP analysis was additionally performed on the important factors of Level 2 that have the highest importance and priority in Level 1. As a result of the AHP analysis, 'Technical Connectivity' was the most important method in the technical factor, and SME experts and academic and research institute experts were highly evaluated for 'commercialization ability' Competence in terms of importance. As for external support factors, it was analyzed that SME experts "support for manpower development" was important, while the other two group experts research and development support was important. In this study, the priority of the government support and policy priorities are suggested according to the capabilities of the railway manufacturing SMEs before the future R&D support.

• Journal of Korean Society of Transportation
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• v.24 no.2 s.88
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• pp.65-78
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• 2006

This paper investigates the cost structure ot the Korea and Japan railroad industry with respect to density, scale and scope economies as well as productivity growth rate using a generalized trans)og multiproduct cost function model. The paper then assumes that the Korea and Japan railway companies pi·educe three outputs (incumbent railway passenger-kilometers. Shinkansen passenger-kilometers, ton-kilometers of freight) using four input factors (labor, fuel, maintenance, rolling stock and capital). The specified cost function includes foul other independent variables: track lengths to reflect network effects, two dummies to reflect nation and ownership effects, and time trend as a proxy for technical change. The simultaneous equation system consisting of a cost function and three input share equations is estimated with the Zellner's iterative seemingly unrelated regression. The unbalanced panel data used in the paper, a total of 154 observations. are collected from the annual records of the Korea National Railroad (KNR) for the yews $1977{\sim}2003$, Japan National Railways (JNR) for the years $1977{\sim}1984$. seven Japan Railways (JR's) for the years $1987{\sim}2003$. The findings show that the Korean and Japanese railways exhibit product-specific and overall economies of density but product-specific diseconomies of scale with respect to incumbent railway passenger-kilometers, Shinkansen-kilometers and ton-kilometers. However, the railways experience mild overall economies of scale which result from economies of scope associated with the joint production of incumbent railway/Shinkansen and feight, freight/incumbent railway and Shinkansen except Shinkansen/incumbent railway and freight. In addition, the economies of density and scale in the KNR, JR east, JR central, and JR west companies at the point of the years $1990{\sim}2003$ average is generally analogous to the above results at the point of sample average. There also appear to be economies of ssope associated with the joint Production of the incumbent railway and Shinkansen in JR central but diseconomies of scope in JR East and JR West. The findings also indicate that the productivity growth rate of the privately-owned JR's is larger than that of the government-owned KNR.

• Journal of the Korea Safety Management & Science
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• v.15 no.4
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• pp.63-72
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• 2013

Recent trends in rail industry can be characterized by the multifunctionality and very high-speed modes of operations. In particular, the adoption of the unmaned or operatorless operations has been getting increased attention in which case ensuring systems safety is crucial. On the other hand, according to the result of analyzing rail accidents, the human/operator errors have turned out to be one of the key causes of the accidents. Therefore, the effort of improving the work environment of locomotive cabs is quite necessary in order to decrease the accidents. The objective of this paper is studying on how to incorporate the factors related to the train operators in the design of the locomotive cabs and also on how to evaluate the design results obtained, which is subsequently reflected in the generation of the test and evaluation procedure. The approach taken is based on systems engineering, yielding the procedure document as a result. The results obtained in the paper can be useful in confirming the design of locomotive cabs utilizing the domestic human/operator measure. Also, the way of achieving the objectives can be utilized to cover the expanded rail systems development with appropriate design activities added.

• Journal of the Korean Society for Precision Engineering
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• v.33 no.7
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• pp.551-558
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• 2016

Reduction of welding residual stress is very important in the railway industry, but calculating its distribution in structures is difficult because welding residual stress formation is influenced by various parameters. In this study, we developed a finite element model for simulating the repair welding process to recover a surface damaged rail, and conducted a series of parametric studies while varying the cooling rate and the duration of post weld heat treatment (PWHT) to find the best conditions for reducing welding residual stress level. This paper presents a three-dimensional model of the repair welding process considering the phase transformation effect implemented by the ABAQUS user subroutine, and the results of parametric studies with various cooling rates and PWHT durations. We found that heat treatment significantly reduced the residual stress on the upper rail by about 170 MPa.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.331-336
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• 2005

A lot of manufacturing knowledge and method have applied to increase manufacturing efficiency in industry field. DES(Discrete Event Simulation) is one of solution to deal with manufacturing problems in factory. Beginning of research, old maintenance system of KNR ( Korea National Railroad) and its technical problems are basically investigated. KNR has maintained railway vehicle with their own solution based on experience. Very advanced railway vehicles such as KTX (Korea Train Express) and TTX(Tilting Train Express) will be difficult to maintain with their old maintenance method. In order to apply knowledge of DES, maintenance field of railway must be considered. Imaginary maintenance machine are selected to variable of DES. Maintenance capability of each machine will be evaluated base on imaginary data from imaginary machine. The machine could be very expensive as well as difficult to replace. Target of research is minimization of number of machine in railway workshop. So basic knowledge of discrete event simulation is introduced. Then five essential stages of discrete event simulation are provided. Each maintenance case defined as event. Each event is discrete and simulated base on different case such as one maintenance line with one machine and one maintenance line with two machines in railway workshop. simple maintenance method, discrete event simulation, will be come out very powerful in complicate maintenance system and will be helpful to reduce maintenance cost as well as maintenance labor.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.64 no.4
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• pp.220-230
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• 2015

Rolling stock RAMS is a field of engineering which integrates reliability, availability, maintainability and safety (RAMS) characteristics into an inherent product design property through rolling stock system engineering process. It is implemented to achieve operational objectives successfully, and recently the RAMS has become a rapidly growing engineering discipline because it has a great potential to ensure safety and improve cost effectiveness. However, the Korean rolling stock industry has not yet implemented RAMS management in the rolling stock engineering process, despite the issue having been addressed since the introduction of the KTX. Thus, this paper discusses the processes, methods and techniques for RAMS assessment in three parts. Firstly, it outlines a process of the overall RAMS performance assessment for achieving technical RAMS design criteria. Secondly, it discusses a process for assessing the operational RAM and allocating the RAM. This paper also proposes a model for assessing safety-based risk management, which includes five analytic techniques for identifying the causes and consequences of a system failure. Finally, a case example is provided for the risk assessment of the pneumatic braking device.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.11
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• pp.1549-1554
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• 2018

Recently the design of railway systems have been performed, based on the analysis of operational conditions and service targets, it is to optimize the effectiveness and efficiency of system operation. Many RAMS requirements have been developed to transform operation conditions into system design characteristics. However, our railway industry has not actived the application of RAMS into system design performance. According to short of RAMS application, many technologies that have been developed are not only applied the existing systems that is operating, but also have not succeed to apply for new systems. In order to design the effective and efficient railway systems that are optimized to operation conditions and service targets, a systems approach and RAMS management are necessary in railway development, operation and maintenance. Therefore, in this study, the RAMS performance requirement design methods are discussed. the allocation methods from system level to each devices of subsystems.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.1108-1113
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• 2004

While the environment of usage of information and technology is getting stable and technology is being developed more deeply due to the globalization, making information, standardization, in order to make a fast response to the new industry strategy and business environment, mutual communication and management of correct and fast information are focused on as fundamental elements of keeping competitive power. Accordingly strategic development of urban transit operation organization, storage of information technology of urban railroad, and buildup of standard information infra are very important, so that computerized information system has been built up standardizing efficient maintenance framework of urban transit facilities. To maintain these facilities efficiently, storing the real-time information by standardizing the maintenance organization and building up computerized information system are very important with management of information history of existing maintenance work. Therefore, for the efficient maintenance of civil facilities among urban transit facilities, standardized facilities classification and definition of management elements, and the plan of designing and building standardized database about civil facilities through standardizing technology resources are described in this paper.