• Proceedings of the KSR Conference
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• 2000.05a
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• pp.143-150
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• 2000

Like conventional railways, improving running performance of vehicle in curve is more effective than improving maximum speed to reduce traveling time. But some vehicles have problems concerning running performance in cure because of insufficient study for our conventional railway characteristics. So, these problems brought about increasement of maintenance cost. This study was started to deliberate several plans to solve problems concerning running performance in curve. Some modifications of primary suspension and tests were carried out to improve curve negotiation. Here, we describe some results.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1134-1141
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• 2011

Costs have long since become a major issue in railway system analysis, attention is not limited to the acquisition costs alone, but encompasses all costs involved in the use and disposal of the systems. Concepts such as Life Cycle Cost(LCC), Costs Of Ownership(COO), or Total Ownership Cost(TOC) are more and more frequent in any document dealing with system analysis. Most of railway projects have applied this LCC Model to evaluate effectiveness of system acquisition cost. But these action of LCC model does not applied all the rest of system life cycle period due to the differences of its responsibility. This is why a study has been undertaken by the operation party to harmonize the most important aspects of the LCC model. This study focused on these and other objectives for introduction of method and needs for an action plan for maintenance actions involved relevant cost allocation.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.1440-1444
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• 2011

Memory-device is one of the auxiliary components of point-switch machine; connecting front-rod and tongue-rail. The right side and left side of memory-device are different from each other. When there would be a derailing accident of rolling stock or motor-car, the memory-device properly bends and protects the internal of point-switch machine. Memory-device is one of the important site maintenance spare parts. Memory-device for each of right and left side should be secured so that they can be installed on correct side during an exchange work. This study suggests the development of memory-device with different left and right side and the performance test of it. The study intends to contribute in the convenience improvement of maintenance by improving the unification of memory-device.

• Journal of Korean Society for Quality Management
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• v.21 no.2
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• pp.109-120
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• 1993

Most systems are composed of components which have different failure chracteristics. Since the failure characteristics of components is different, it is rational and reasonable to establish a maintenance model to be considered repair and replacement policies which are proper to failure characteristics of these components. This paper proposes the age replacement time for a system composed of components which have different failure characteristics. In this model, it is assumed that a system is composed of a critical failure component, a major failure component, minor failure component. If any failure occurs to critical component before its age replacement time, the system should be replaced. If any failure does not occur until its age replacement time, preventive replacement should be performed at age replacement time T. Major component is minimal repaired if any failure occurs during operation. Minor component should be replaced as soon as failure is found. This paper determines the optimal replacement time of the system which minimize, total maintenance cost and initial stock Quantity of minor component within this optimal replacement time. Numerical example illustrates these results.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.197-205
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• 2007

Radio frequency identification, or RFID, is a generic term for technologies that use radio wave to automatically identify people or objects. UHF RFID technology is used for everything from tracking goods within their supply chain, working in process and for other applications. If RFID is applied in wheel scanner that is a important equipment to measure a diameter, width, height of wheel, efficiency in maintenance will be improved because of checking data in real-time. In domestic technology, capacity of wheel scanner technology as well as RFID are less good than foreign goods there a up to current day a point of read range, anti-collision, a tolerance. Therefore, sturdy on the development of wheel scanner using RFID technology to measure wheel in maintenance of rolling stock was carried out in this paper.

• Smart Structures and Systems
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• v.5 no.2
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• pp.173-191
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• 2009

Civil infrastructures are always subjected to various types of hazard and deterioration. These conditions require systematic efforts to assess the exposure and vulnerability of infrastructure, as well as producing strategic countermeasures to reduce the risks. This paper describes the needs for and concept of advanced sensor technologies for risk assessment of civil infrastructure in Japan. Backgrounds of the infrastructure problems such as natural disasters, difficult environment, limited resource for maintenance, and increasing requirement for safety are discussed. The paper presents a concept of risk assessment, which is defined as a combination of hazard and structural vulnerability assessment. An overview of current practices and research activities toward implementing the concept is presented. This includes implementation of structural health monitoring (SHM) systems for environment and natural disaster prevention, improvement of stock management, and prevention of structural failure.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.742-747
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• 2008

This paper is described the systematic activities of RCM to improve the availability for AREX railway system. The purpose of these activities are to maintain and enhance the reliability, availability, maintainability and safety, and to implement the effective maintenance for electrical and mechanical system including rolling stock, signalling, telecommunication, power supply, overhead catenary and platform screen door with impact to train operation.. The main activities consist of systematic failure and repair recording by integral information system, analysis and corresponding countermeasure. As applying these activities in opeartion and maintenance works, the availability of AREX railway system is going on improvement gradually, and maintenacne works are improved with these results.

• International Journal of Railway
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• v.3 no.1
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• pp.34-37
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• 2010

In recent, the railway system consists of subsystems as rolling stock and infrastructures as signaling, telecommunication, power supply, overhead contact and platform screen door, etc. Furthermore, each subsystem has complicated interface so as not to understand these relationship. Consequently, to operate the railway system continuously with required safety and availability, the failure data should be corrected and analyzed systematically during operation. To achieve this object effectively, this paper presents the method which is evaluating the operational risk quantitatively using failure data, and selecting the critical equipment. Following this analysis, the improvement plan is established and applied to reduce the operational risk on system or equipment. From this study, the critical equipments of system could be determined and prioritized by risk analysis. Also, the effective maintenance to prevent critical failure could be implanted by this suggested methodology.

• Journal of Venture Innovation
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• v.7 no.1
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• pp.17-39
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• 2024

The purpose of this study was to analyze the effect of the government's R&D support and the use of stock options by venture companies on the innovation of venture companies, that is, innovation capabilities and innovation performance. An empirical analysis was conducted using the partial least squares structural equation modeling (PLS-SEM) method using the data from the detailed survey of venture companies conducted on domestic venture confirmation companies. As a result of the analysis, it was found that the benefit of government R&D support had a positive (+) effect on strengthening the innovation capabilities of venture companies, and R&D support also had a positive (+) effect on the innovation performance of venture companies. Next, it was found that the use of stock options by venture companies had a positive (+) effect on the reinforcement of the innovation capabilities of companies and a positive (+) effect on the innovation performance of venture companies. In addition, it was found that the innovation capabilities of venture companies significantly mediate between the government's R&D support and the use of stock options by venture companies and the innovation performance of companies. These analysis results show that the government's R&D support and the use of stock option systems can play a meaningful role in the innovation of venture companies, and also show that the innovation capabilities of venture companies have an important meaning in the process of innovation. Therefore, it is necessary to continue the stance of R&D support for ventures and at the same time to introduce multi-faceted policy measures to support corporate capacity building, and legal and institutional maintenance and policy support to revitalize the stock option system need to be continuously provided.

• Korean Journal of Construction Engineering and Management
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• v.2 no.1 s.5
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• pp.57-67
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• 2001

In 1999, a residence stock amounts to 11 million units and apartment housing holds 57.6 percent of the residence stock. Without proper remodeling for apartment housing, a significant portion of them would be expected to be demolished shorter than their life-time due to socioeconomic reasons. Apartment housing is maintained depending on government regulations such as 'Housing Construction Promotion Code' and 'Apartment Housing Maintenance Ordinance'. However, there are many problems with implementation of them. In order to solve the problems, we focus on the remodeling system that includes Maintenance of Apartment Housing, Finance and Taxation, Special Repair Appropriation Budget, Resource Quality and Standard Plan, and Remodeling associated with the code. And this study, which being compared with the foreign remodeling system, presents the improvement scheme of system for apartment housing remodeling. This study aims to promote remodeling apartment housing and provide the suitable scheme for remodeling activities.