• 열처리공학회지
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• 제18권5호
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• pp.297-304
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• 2005

This study was performed to determine the repair weldability of the damaged Ni type superalloy used for gas turbine blade. The experimental works included the evaluation of the microstructures of the damaged blade, selection of the repair welding procedure, characterization of repair weldment and finding the heat treatment procedures for repaired weldment. The morphology of the microstructure for the base metal was composed of austenite matrix with cubical ${\gamma}^{\prime}$ phase, MC type coarse precipitates located within grain and fine $M_{23}C_6$ type precipitates decorated at grain boundaries. The repair welding process using 90 amp current exhibited the best weld properties showing no weld microcracks. The solution and aging heat treatments of the repaired weldment could recover the original service properties of the damaged blade.

• 국제학술발표논문집
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• The 4th International Conference on Construction Engineering and Project Management Organized by the University of New South Wales
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• pp.376-381
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• 2011

In Korea Water Resources Corporation (K-Water) has seen four problems rising in four aspects of property management of approximately 1,300 buildings scattered through put to country. To solve these, ground data for repair and replacement works to be conducted for prevention will be prepared and building maintenance system (hereinafter referred to as PBMS) intended to record related repair and replacement work histories and calculate LCC of the related these items will be developed. PBMS, a web-based system, will be developed for users' convenience and data monitoring in real time. To sum up, PBMS are expected to maximize efficiency in four aspects including the establishment of repair and replacement work plans for prevention, history management, DB for predicting future work to be occurred and enable the determination of priorities by being developing into facility condition assessment systems through the results of analysis of repair and replacement histories and LCC.

• 대한전자공학회논문지SD
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• 제44권12호
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• pp.85-92
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• 2007

메모리 설계 기술과 제조 공정의 발전에 따라, 고집적 메모리의 생산이 본격화 되었다. 이러한 메모리의 고집적화는 복잡하고 정밀한 설계와 제조 공정을 필요로 하기 때문에, 메모리 내에 더 많은 고장을 존재할 가능성을 낳았다. 이에 따라 메모리에서 발생하는 여러 고장을 분석하고 메모리를 수리하여 공정상의 문제를 수정하기 위해, BISR(Built-In Self-Repair) 회로의 중요성이 부각되고 있다. 본 논문에서는 주어진 예비 메모리를 효율적으로 사용하여 고장이 발생한 메모리를 효과적으로 수리할 수 있는 메모리 내장형 자체 수리 회로의 구조와 그 방법론에 대해서 소개하고자 한다. 제안하는 자체 수리 회로는 sign bit이라는 추가적인 저장 장치를 이용하여 메모리 수리를 수행한다. 이는 기존에 비해 좀 더 향상된 성능을 가지고 있다.

• 건축역사연구
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• 제23권1호
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• pp.7-19
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• 2014

This study considers the proper repair techniques by examining the most representative repair cases of the Korean arch bridges and proposes the constructional manual which can apply similar occasions. The cases are Seonamsa Seungseongyo and Songgwangsa Geukrockgyo where this researcher had taken part in the repair works. This Study proposes the maintenance construction manual about the performance degradation drew by performance degradation of the both Korean arch bridges in the maintenance process. First, arch bridge maintenance should be carried out in the dry season, when water is impermeable in the bottom surface of the bridge. Moreover, risk factors of the maintenance should be excluded to secure the water vally flow, the bypass and the temporary bridge. Second, prior to repair, it has to precede (1)3D shooting (2)formal examination (3)structure safety test (4)geological and lithic surveys (5)arch curvature establishment and makeshift frame settlement before transformation (6)relationship expert comments. Third, if the baduk and the foundation stones are inevitable to replace due to performance degradation on the foundation, it should use the high quality stones and secure greater stress by extending the standard range. The foundation on irregular rock needs to be flattened and underside on the replaced materials require Grengyijil to deliver the equal loads. Fourth, In the process of dismantling the stones of the arched bridge, it could make heavy weathering degree and not reuse the materials. Charge should converge the expert advices to choose the reuseable, the conservate and the alternative materials, and increase the reutilization of the raw materials by preservation and reinforcement treatments. Fifth, the side wall should be repaired by the rubble work technique which is not able to pile compost satiety, so it must use long depth of masonary stones for reinforcement. It is considered to reinforce the stone wall in shore as much as possible and protect the abutment and the side wall on the upstream for the arch bridge maintenance works.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.856-863
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• 2009

The problem of urban decay in Hong Kong has drawn much attention of both practitioners and academics. Poorly managed buildings not just give a negative image to the Pearl of the Orient in the region, but also pose potential risk hazards to the health and safety of the general public. While it is necessary to devise a comprehensive plan on redevelopment and urban planning, preserving the existing buildings to maintain their conditions for habitation can be a short-term option to safeguard quality standard. With the increasing number of ageing buildings in Hong Kong, a lot of research efforts have been devoted to managing repair and maintenance projects properly (for example those initiated and funded by the Construction Industry Institute, Hong Kong; and the current study financially supported by The Hong Kong Polytechnic University). Given the short duration and more diversified nature of work, building repair and maintenance works are found to be more difficult to monitor and regulate when compared with new works. This paper aims to provide a comprehensive analysis on the problems of running building maintenance projects. An extensive review of contemporary literature was firstly conducted, which forms a solid basis for developing an empirical study on the problems and difficulties of running building maintenance projects from the viewpoints of industrial practitioners with a view to formulating effective strategies for managing maintenance projects successfully.

• 한국생산제조학회지
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• 제6권4호
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• pp.9-18
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• 1997

It is proposed a new approach to the development of the automatic vision system to examine and repair the steam generator tubes at remote distance. In nuclear power plants, workers are reluctant of works in steam generator because of the high radiation environment and limited working space. It is strongly recommended that the examination and maintenance works be done by an automatic system for the protection of the operator from to radiation exposure. Digital signal processors are used in implementing real time recognition and examination of steam generator tubes in the proposed vision system. Performance of proposed digital vision system is illustrated by simulation and experiment for similar steam generator model.

• 한국농공학회:학술대회논문집
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• 한국농공학회 1998년도 학술발표회 발표논문집
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• pp.99-106
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• 1998

A study was conducted to develope a system for optimum design, safe appraisal and repair works on agricultural structures. Locations of structures were identified using GPS and imbedded into GIS data base with related information. A graphical program assisting ensile field investigation of typical agricultural structural problems such as fractures and cracks of members was developed. Typical rehabilitation methods were coded for data base development. Optimum design programs for several structures were developed and CAD program which automatically draw draft was also developed.

• 기술사
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• 제45권4호
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• pp.62-66
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• 2012

농업기반시설인 저수지의 효율적 관리를 위하여는 관리주체의 일원화, 전문가 집단에 의한 과학적 관리를 위한 인력양성 및 배치를 통한 선량한 관리체계 확립이 필요하고, 정기적 정밀안전 진단 결과에 의한 보수보강이 이루어지도록 관리체계의 시스템화가 요망된다. 특히 정기적인 정밀점검 및 정밀안전진단을 실시하여 시설물의 기능성, 안전성 등을 점검 또는 진단하고 그 결과에 따라 변화된 자연환경에 걸맞는 시설기준을 충족시킬 수 있는 적절한 보수 보강방안을 실시하도록 지속적인 예산지원은 물론 관리주체의 선량한 관리의식이 요망된다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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• pp.932-937
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• 2008

The asphalt waste has been collected more than ten thousands' ton from repairing works on the road and excavation repair works, most of them are disposed on land of reclamation. Only a few percentage of wasted asphalt recycled to new one. Therefore, In this study, usage of wasted asphalt and has been done engineered characteristic test for recycling materials of sub-grade and structure. To know the characteristic of asphalt waste, tamping test, bearing-ratio test, permeability test and direct shear test was done using asphalt-sand mixture. The test results shows that, mixed asphalt materials with sand can be used for materials of subgrade-soil and structure.

• 제어로봇시스템학회논문지
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• 제4권5호
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• pp.658-665
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• 1998

In this paper, we propose a new approach to the development of the automatic vision system to examine and repair the steam generator tubes at remote distance. In nuclear power plants, workers are reluctant of works in steam generator because of the high radiation environment and limited working space. It is strongly recommended that the examination and maintenance works be done by an automatic system for the protection of the operator from the radiation exposure. Digital signal processors are used in implementing real time recognition and examination of steam generator tubes in the proposed vision system. Performance of the proposed digital vision system is illustrated by simulation and experiment for similar steam generator model.