• Title/Summary/Keyword: Repair Work

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A Very Efficient Redundancy Analysis Method Using Fault Grouping

  • Cho, Hyungjun;Kang, Wooheon;Kang, Sungho
    • ETRI Journal
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    • v.35 no.3
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    • pp.439-447
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    • 2013
  • To increase device memory yield, many manufacturers use incorporated redundancy to replace faulty cells. In this redundancy technology, the implementation of an effective redundancy analysis (RA) algorithm is essential. Various RA algorithms have been developed to repair faults in memory. However, nearly all of these RA algorithms have low analysis speeds. The more densely compacted the memory is, the more testing and repair time is needed. Even if the analysis speed is very high, the RA algorithm would be useless if it did not have a normalized repair rate of 100%. In addition, when the number of added spares is increased in the memory, then the memory space that must be searched with the RA algorithms can exceed the memory space within the automatic test equipment. A very efficient RA algorithm using simple calculations is proposed in this work so as to minimize both the repair time and memory consumption. In addition, the proposed algorithm generates an optimal solution using a tree-based algorithm in each fault group. Our experiment results show that the proposed RA algorithm is very efficient in terms of speed and repair.

Case Study of F-15 Airframe Battle Damage Repair Design and Assessment Procedure (F-15 기체 전투손상 수리설계 및 평가기법 사례연구)

  • Kim, Jong-Heon;Joo, Young-Sik
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.37 no.1
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    • pp.105-112
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    • 2009
  • For the purpose of facing battle damage that a fighter is subject to in combat, following recovery procedures such as damage assessment, repair design and structural integrity evaluation are investigated. A sample study is presented on the battle damage of F-15 ECS bay, which is comprised of damage assessment and repair design based on ABDR(Aircraft Battle Damage Repair) skills and work procedure complying with AFTO(Air Force Technical Order) forms. Further, the flight safety of repaired structure is validated and the time the permanent repair should be done is estimated through the evaluation of structural integrity such as the calculation of static strength and fatigue life.

A STUDY ON THE PROCESS OF LARGE-SCALE REPAIR OF A CONDOMINIUM

  • Seki, Eiji;Akiyama, Tetukazu
    • Proceeding of Spring/Autumn Annual Conference of KHA
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    • 2002.11a
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    • pp.295-300
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    • 2002
  • Since the contents of large-scale repair of a condominium were various, a plan document was not prepared. The owners association of the condominium has given priority to decision-making of price priority over quality. Examination is not performed about the contents of the construction supervision business, which checks whether suitable construction is performed, either. On the other hand, the know-how for builders, such as decision of the process plan under which the repair work lessens influence to the safety and life as much as possible since the place where the resident is living turns into a construction site, and selection of a method of construction, is just going to ask. It is an important subject how the structure of the construction contractor selection, which considered quality, is built. Then, this research focuses on large-scale repair construction of the condominium, and arranges the actual condition of a series of processes from plan document creation to construction supervision. The method of research collects the construction documents of the condominium that carried out Barge-scale repair construction. Next, collection arrangement of the data of construction builder selection is carried out. The method of the construction builder selection of those other than a construction price is examined. The method of quality control of large-scale repair construction is examined.

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A Comparative Study on the Repair Performance of Concrete Crack (콘크리트 균열 보수성능에 관한 비교 연구)

  • 박성우;윤성훈
    • Proceedings of the Korea Concrete Institute Conference
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    • 2002.10a
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    • pp.817-822
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    • 2002
  • The problem of the crack which occures from the reinforced concrete structure could be caused by the complexed factors. When the crack happen, it caused fatal blemish to manage and maintain the structure such as structural problem, licking, spalling, viewing Even though they study and work hard to solve this kind of problem in the world, there are no countermeasure for perfect prevention of crack. After the crack checked out, a method of repair-reinforcement has been studied and operated actively, Generally, occurance of the crack in the concrete structure could be taken as granted, no need to mention the damage from the crack, domestic construction try to hide it rather than repair basically, In many cases the construction amount for repairing the crack has to be made in the construction area and the amount is very expensive. To save the repaing fee, companys repair it under the meeting of their desire. it can be expected for the effection of the construction. For this reason, we compare a new injection method to solve the demerits of the present method, to save and use the merit of the present method.

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A Study on the Experimental Study on Use Proper of Superplasticizer for Repair Mortar (보수 모르타르용 고성능 유동화제의 사용 적합성에 관한 실험적 연구)

  • Kim, Young-Sam;Song, Tae-Hyeob;Lee, Mun-Hwan;Lee, Sea-Hyun
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.05b
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    • pp.297-300
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    • 2006
  • Recently, To extend building's life, the use amount of repair mortar has been rapidly increased and naphthalenesulfonic and melanminesulfonic, polycarboxylic superplasticizer etc. are used for repair mortar in large numbers of construction site for efficient work. In this study, it was going to examine the use proper of superplasticizer for repair mortar through the hydrate setting time test and flow test with the mortar combination which replaced by alumina cement and added superplasticizer. As a result, the fluidity of the mortar replaced by alumina cement(10%) and added superplasticizer was dropped down and setting time was shortened. Especially this appearance was more increased on the mortar combination added ploycarboxylic and melanminesulfonic superplasticizer than naphthalensulfunic superplasticizer.

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An Experimental Study on the Evaluation of Injection-ability for Concrete Crack-Repair Materials by using Ultrasonic Pulse Measurement Method. (초음파 측정법을 이용한 콘크리트 균열보수재의 충전성능 평가에 관한 실험적 연구)

  • Lee, Sang-Hyun;Lee, Han-Seung;Park, Sung-Woo
    • Proceedings of the Korea Concrete Institute Conference
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    • 2005.05a
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    • pp.515-518
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    • 2005
  • A concrete is easy to happen crack. So it requires crack-repair work to solve quality deteriorations of a building because of cracks. When crack is filled with crack-repair materials, it is difficult to find out how depth it was injected. So in this study we evaluated the injection depth with using indirect and oblique methods, ultrasonic pulse measurement method of NDT. The results of this study showed that both methods are possible to evalute penetration depth of crack-repair materials and indirect methods is thought to be more useful one than obliqure one.

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Applying BIM and GIS to Railway Maintenance Works in Taiwan

  • Liu, Li-Shih;Shr, Jin-Fang
    • International Journal of Aerospace System Engineering
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    • v.2 no.1
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    • pp.18-23
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    • 2015
  • Based on real jobs, this study was carried out the Railway maintenance works in Taiwan. It hopes to use Geographic Information System(GIS) and Building Information Modeling(BIM) for changing the maintenance model from "post-damage repair" to "preventive maintenance". Accordingly, this research will build a Railway Repairing Database that installs all repair data. This database will also connect to GIS so that can be the source of analysis and statistic for repair paln. The main results of research are as follows: I. All data stored on cloud space that raises the ability to manage and plan on repair. II. Simplify the file work and increase the quantity of case data to the manager who can get more reliable source. III. The data offer objective judgment to avoid subjective argument. IV. Add the GIS information to improve the maintenance because of good analisis.

A Study of the Wall Repair Record and Construction Technology of Geungnakbojeon Hall at Muwisa Temple in Gangjin (강진 무위사 극락보전의 벽체 수리 기록과 시기별 시공기술 고찰)

  • Hong, Eunki
    • Korean Journal of Heritage: History & Science
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    • v.53 no.2
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    • pp.140-155
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    • 2020
  • The purpose of this study is to examine historical wall repair details through analysis of repair data and administrative documents of the Paradise Conservation of Gangjin Muwisa Temple. In addition, the purpose of the project is to examine the differences and commonalities between the materials and construction technology used in the building's walls. The data for repair work conducted in 1935, 1956, and 1982~3 was analyzed and the results of the research were as follows. First, data for the wall construction conducted in 1935 during the dismantling repair showed that the interior structure of the wall was found to follow that of the original, but the first, second, and final layers used different materials. The composition material of the wall consisted of clay, lime and sand, the second layer used sand and plaster, and the last layer used plaster and seaweed paste. Second, the structure of the wall interior, which was found during the 1956 repairs, consisted of wood woven horizontally and vertically. It was confirmed that this had been installed diagonally using a rope. Third, the 1982~3 repair work confirmed that the wall's interior construction conformed to the original method. The lime-sand wall was formed by mixing slacked lime, sand, soil, fodder, and seaweed grass. Fourth, when the various repairs are considered as a whole, it is clear that the interior structure of the wall was made more than 1900 years ago, and the material used in the wall changed in 1935. Fifth, the materials used for each repair differed, but each project had a common view of cultural heritage repair principles in sections that stated the significance of each project.

The Analysis and Forecasting Model for Maintenance Costs Considering Elapsed Years of Old Long-Term Public Rental Housing (노후 장기공공임대주택의 경과 연수별 유지관리비 분석 및 예측 모형)

  • Jung, Yong-Chan;Jin, Zheng-Xun;Hyun, Chang-Taek;Lee, Sanghoon
    • Korean Journal of Construction Engineering and Management
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    • v.23 no.3
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    • pp.83-94
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    • 2022
  • The number of public rental housing has increased according to the government's 「Housing Welfare Roadmap (2017)」, and facility maintenance costs for the demand of improvement of performance and residential standards due to the aging of long-term public housing are significantly increasing. Consequently, the financial burden of public housing rental business for maintaining stocked housing is aggravated. However, there is a lack of objective data to analyze the size of the maintenance costs that are executed by the type of repair work, and the elapsed years of the aged long-term public rental housing. This study analyzes the execution status of 33 long-term public rental housing complexes located in Seoul for 14 to 28 years of elapsed years based on the data of maintenance costs. In addition, this study proposes a model to predict the maintenance costs by elapsed years by dividing 'Long-term Repair Plan Work and Government-Funded Project [Y1]', 'Planned Repair Work and General & Unplanned Repair Work [Y2]', and 'Total maintenance costs [Y3]'. It is intended to be used as basic data for the establishment of the maintenance plan at the stage of setting up the budget and the establishment of the sustainable operation plan for public rental housing

A Study on the Existence of Lime Plaster Wall in the Joseon Dynasty, Based on the Analysis of Construction Reports of 'Sanleong-Uigwe' & 'Yeonggeon-Uigwe' - Emphasized on the Government Building Constructions - (산릉.영건의궤 분석을 통한 조선시대 건축에서 회벽의 존재 여부 고찰 -조선 후기 관영건축을 중심으로-)

  • Lee, Kweon-Yeong
    • Journal of architectural history
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    • v.19 no.3
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    • pp.89-106
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    • 2010
  • Since the 1970's, UNESCO and ICOMOS have adopted or emphasized on the principles of historic preservation. One of them is what to require a repair should not be repaired beyond the limits of the features and techniques which had been adopted in those days of establishment. On the premise, this paper is to examine the materials and technique of wall plaster work in the government building constructions in the Joseon dynasty. The result of this examination shall come up with a basic conformity in the case of repairing the building established in the late of Joseon dynasty. This paper is carried out for the proper repair and restoration of architectural cultural properties. Construction reports and other documents in those days are examined for the study. Following conclusions have been reached through the study. The materials and technique which applied to wall plaster work in those days were quite different from the present. The technique that was used to wall plaster of government buildings in those days was not a lime wall plaster, but sand coat one. The kinds of material for setting of the sand coat wall plaster had been revised with the change of the times or constructions. The main kinds of material were composed of sand, white clay, paper fiber, and cereal starch. However, the present materials were composed of sand, white clay. Therefore, the present materials and technique which applied to wall plaster work for the repair and restoration of architectural cultural properties have to be revised and corrected.