• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.84-90
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• 2009

The gravel ballast in the ballasted track has the function to not only transfer/scatter the train loads to subgrade through rail and sleeper but also elastically support the train loads. Because track irregularities results inevitably from the repetitive train loads, the track maintenance should be undertaken for correcting them. By analyzing the track maintenance history in the Gyeongbu high speed railway, this study tries to choose the local two spots in the railway in which the repair frequencies are maximum and relative small; to analyze their dynamic characteristics as well as grade; and to compare them with maintenance history. As the dynamic characteristics of track, the vertical displacement and vibrating acceleration of sleeper as well as acceleration of ballast are measured/analyzed. Furthermore, by collecting soil and gravel on the reinforced roadbed and undertaking ballast screening test, the size distributions are compared with grade distribution standards of high speed railway.

• International Journal of CAD/CAM
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• 제9권1호
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• pp.71-77
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• 2010

Various applications, such as mesh composition and model repair, ask for a natural stitching for polygonal surfaces. Unlike the existing algorithms, we make full use of the information from the two feature lines to be stitched up, and present an accurate stitching method for polygonal surfaces, which minimizes the error between the feature lines. Given two directional polylines as the feature lines on polygonal surfaces, we modify the general placement method for points matching and arrive at a closed-form solution for optimal rotation and translation between the polylines. Following calculating out the stitching line, a local surface optimization method is designed and employed for postprocess in order to gain a natural blending of the stitching region.

• 대한안전경영과학회지
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• 제8권5호
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• pp.167-180
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• 2006

This study expands limitation of OASIS(Optimal Allocation of Spares for Initial Supports) program, which calculates CSP(Concurrent Spare Part), not only availability but also cost, and developed the program enabling run in WINDOW OS. By considering multi-step repair and logistics support system, repairing capability at the time of deployment, and procurement period, this model is the first local model reflecting circumstances of the armed forces of the Republic of Korea. Furthermore, the programmed model was selected as the military standard software and has being essentially used for CSP calculation.

• 한국농촌건축학회논문집
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• 제8권3호
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• pp.91-100
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• 2006

The purpose of this study is clear the characteristic of the condition of conservation and rehabilitation by investigates of Modern Architecture (Cultural Properties 51, common architecture 93, total 144) in Kyoto-city. In registration system for conservation of Modern Architecture of Kyoto city, regulation is stricter than statute of country and various assistances of repair and so on are adopting more active incentive policy. The condition of ownership of Cultural Properties is almost corporation or foundation and individual ownership is dwindling. Various portion conservation ways (annex facade elements replica) are appearing by technique assistance means to keep the original form. It is increase that the conditions of rehabilitation are to commerce equipment or open to the public as like an exhibition hall. In case of renovate to commerce equipment, tendency as cultural-composition equipment is increasing as like a local community.

• 한국철도학회논문집
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• 제7권3호
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• pp.223-231
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• 2004

The accumulated BMS data have made it easy to make reasonable decision-making for bride maintenance and repair work. In the developing period of BMS, the bridge management was not easy due to the lack of understanding of BMS and low credibility of the data. In recent years, it has been possible to enhance the credibility of the data and to expand the application scopes of BMS with the efforts of Local Road Construction Offices. The reasonable decision making for bridge management can improve the performance of bridges under the practical constraints such as limited budget. It can then result in the reduction of bridge maintenance budget. This study provides the methodology for the application of mobile internet-based KOBMS for bridge management. The data flow for BMS is the most important factor for decision-making on budget allocation, and this study establishes the basic scheme of the data flow for BMS. The implementation of PDA for BMS may suggest a new paradigm of 'Mobile' in the field of construction management.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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• pp.552-554
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• 2003

This paper is about the method by which Power Control Unit(PCU) of Control Rod Control System(CRCS) logs events in the system and the real-time monitoring display. This method enables the functions like the event logging of Control Rod Drive Mechanism(CRDM)/power Cabinet, the off-line show of the event data logged and the on-line show by communication between the PCU and the monitoring display. Operators in a nuclear power plant must be able to grasp any possible abnormal states correctly. Because our newly designed system has a good ability to log and display the kinds, tine, and the prior and posterior states of urgent or non-urgent events, the operators can judge, maintain and repair the abnormal event more easily.

• 한국표면공학회지
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• 제34권4호
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• pp.289-296
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• 2001

Ni-P electroformed layers were investigated for developing a steam generator tube repair technology in PWRs. The effects of an additive, RPP (Reagent over Pitting Protection) and agitation on mechanical properties and microstructure of the layer were evaluated. The addition of the RPP showed to inhibit the formation of pores, to refine the grain size, and to increase the residual stress in the layer. However, the agitation of the solution during electroforming was observed to increase pores in local regions of the electroformed layer, resulting in decreasing its mechanical properties. The heat treatment of the layer at $343^{\circ}C$ for 1 hr. precipitated the very fine particles of Ni3P in the layer, which inhibited grain growth and increased microhardness.

• 한국표면공학회지
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• 제47권5호
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• pp.244-251
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• 2014

In recent years, self-healing coatings have been the subject of increasing interest. The ability of such coatings to self-repair local damage caused by external factors is a major factor contributing to their attractiveness. Metals are extensively used in modern society in a range of applications from infrastructure to aircraft to consumer products. The protection of metals, primarily from corrosion has been an active area of materials science for many years. The aim of this review is the demonstration for recent progress achieved in the development of carrier-based self-healing coatings for the protection of metals. This review mainly covers the reports published after 2010. Two main types of carriers for corrosion inhibitors or healing agents-polymer capsules and porous composite inorganic nanoparticles-are described.

• Archives of Plastic Surgery
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• 제46권4호
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• pp.371-374
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• 2019

Umbilical preservation can be challenging, particularly in complex cases involving simultaneous ventral hernia repair and abdominoplasty. Although the umbilicus serves no functional purpose, removal of the umbilicus can draw unwanted attention to the abdominal area and can cause emotional distress to patients. There are several well documented options for umbilical reconstruction. We present a new umbilical reconstruction technique relevant for such cases. This neoumbilicoplasty allows for preservation of the original umbilicus with relocation and reconstruction using local flaps. The technique is relatively simple and the time needed is minimal. The result is a natural, well positioned umbilicus using the principles of spare part surgery.

• Smart Structures and Systems
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• 제22권6호
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• pp.699-709
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• 2018

With increasing traffic volumes and rising vehicle traffic, especially in cities, the number of pedestrian bridges has also increased significantly. Like all other structures, pedestrian bridges also suffer damage. In order to increase the safety of pedestrians, it is necessary to identify existing damage and to repair them to ensure the safety of the bridge structures. Owing to the shortcomings of local methods in identifying damage and in order to enhance the reliability of detection and identification of structural faults, signal methods have seen significant development in recent years. In this research, a new methodology, based on cone-shaped kernel distribution with a new damage index, has been used for damage detection in pedestrian truss bridges. To evaluate the proposed method, the numerical models of the Warren Type steel truss and the Arregar steel footbridge were used. Based on the results, the proposed method and damage index identified the damage and determined its location with a high degree of precision. Given the ease of use, the proposed method can be used to identify faults in pedestrian bridges.