• Journal of the Korean Society for Heat Treatment
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• v.18 no.5
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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.

• International Journal of Railway
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• v.2 no.1
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• pp.30-36
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• 2009

Crack and its damage of structure concrete in both FBS and TBS ballastless track are presented. The cause of concrete crack is analyzed. According to corresponding quantitative equation, effective technical measures to depression crack of concrete are put forward, at the same time the rationality of elastic ratio for HGT has been proved. At last, by the analysis of the characteristic of high-speed train, which are serving in the open air, bearing fatigue load, the short time for maintenance window and high speed of service, technical requirement for concrete repair material, repair technology and repair tools of ballastless track structure are presented.

• Proceedings of the KWS Conference
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• 2006.10a
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• pp.277-279
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• 2006

Due to the numerous environmental factors, cracks and corrosion are frequently occured especially in old steel bridge, which deteriorate the structural integrity; thus bring about the problems of structural safety of the steel bridge. Therefore, repair and reinforcement are required for the damaged structure. the replacement repair welding method is spotlighted for its brilliant features, i.e. it can be achieved without incurring traffic dislocation. the method cuts the damaged parts and replaces them with new steel plate by welding under live loads. However, the mechanical behavior of the welded joints under cyclic loads due to the traffic which passes along bridge is not clarified. In this paper, the fatigue strength of the replacement repair welded joints was investigated in order to improve reliability in the repair welded joints of old steel bridge.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.621-624
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• 2006

In this study, the repair method using PVA fiber reinforced mortar evaluated on durability performance. Test of salt injury, carbonation, freezing-thawing, chemical attack, permeability was performed As for the test results, it was found that durability performance of the repair method using PVA fiber mortar showed more better than the existing repair method. Therefore, appling on the repair method using PVA fiber reinforced mortar, the repaired concrete structures can be increased to service life.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.8 no.3
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• pp.221-226
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• 2014

The purpose of this study is to suggest improvement directions and analysis of assistive technology service linkage on public benefits in local assistive technology center. The service steps and the main program parts of public benefits linkage in local assistive technology center was identified, and the present status of associated repair works and contact suppliers of assistive technology device in local community was investigated. The result showed the most common level of associated status to provide information of assistive technology devices in public benefits. All the centers provided repair service, and it was typically performed to light maintenance. The centers offered with associated professional repair service supplier for high maintenance service. The connection with assistive technology device supplier appeared a lot of regional difference. Henceforth, the centers will be required to distribute more various assistive technology devices, it is necessary upgrading the quality of information and interaction with the public benefits supporting organizations through its expansion, and it is need to ensure based on policy through the analysis of the effectiveness about linkage.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.309-312
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• 2006

In this study, the repair method using PVA fiber reinforced mortar evaluated on durability performance. Test items are compressive strength, flexural strength, carbonation, freezing-thawing. As for the test results, it was found that durability performance of the repair method using PVA fiber mortar showed more better than the existing repair method. Therefore, appling on the repair method using PVA fiber mortar, the repaired concrete structures can be increased to service life.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.1
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• pp.32-39
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• 2018

Repairing timing and the extended service life with repairing are very important for cost estimation during operation. Conventionally used model for repair cost shows a step-shaped cost elevation without consideration of variability of extended service life due to repairing. In the work, RC(Reinforced Concrete) Column is considered for probabilistic evaluation of repairing number and cost. Two mix proportions are prepared and chloride behavior is evaluated with quantitative exterior conditions. The repairing frequency and cost are investigated with varying service life and the extended service life with repairing which were derived from the chloride behavior analysis. The effect of COV(Coefficient of Variation) on repairing frequency is small but the 1st repairing timing is shown to be major parameter. The probabilistic model for repairing cost is capable of reducing the number of repairing with changing the intended service life unlike deterministic model of repairing cost since it can provide continuous repair cost with time.

• Steel and Composite Structures
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• v.9 no.2
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• pp.103-118
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• 2009

It has been reported that more than thirty five percent of steel bridges in the USA are structurally deficient because of structural degradations. The degraded structures need either full replacement or rehabilitation such that they are able to provide the required services for a longer period of time. The cost for repair in most cases is far less than the cost of replacement. Moreover, repair method generally takes less time than replacement and also reduces service interruption time. Modern advanced composites have been used in aerospace and automotive fields since World War II. In the recent past, because of the high strength-to-weight ratio and high stiffness-to-weight ratio, these composite materials have been introduced to civil engineering infrastructures primarily for repair and rehabilitation of concrete structures. However, only a few preliminary studies on repair of corroded steel structures using theses composite materials are reported in the literature available in the public domain. Thus, in this study, a series of laboratory tests was undertaken to evaluate the effectiveness of this repair method using carbon fiber reinforced polymer composite. The paper discusses the test method and test results obtained from these tests.

• The Academic Congress of Korean Shoulder and Elbow Society
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• 2009.03a
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• pp.49-51
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• 2009

• Journal of Korean Physical Therapy Science
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• v.9 no.3
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• pp.129-140
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• 2002

This study intended to find out how the handicapped use medical aid, their satisfaction at using it and so on. First a preliminary survey(Apr. 20$\sim$24, 2002) was made for the handicapped who had been cured for rehabilitation by wearing medical aid at hospitals and welfare center in Jeonbuk region. Then total 120 subjects were asked to fill out a standardized questionnaire from May 15$\sim$22, 2002. Out of total 95 questionnaires collected, 84 questionnaires were analyzed except for 11 cases unsuitable for the intention of this study. The results can be outlined as follows: 1. In general characteristic, it was found that the causes of disability included disease(35 respondents; 41.7%), traffic accident(23 respondents, 27.4%) and so on. In addition, 1st handicap comprised the majority(32 respondents; 58.2%) in handicap grade and ankle foot orthosis(or b-k orthosis) was most often used as medical aid(28 respondents: 33.3%) 2. In particular, it was also shown that the 1st handicap mainly resulted from traffic accident(15 respondents, 27.3%) and post-disease disability (11 respondents, 20.0%). They wore medical aid for 1 year or less on the average, because they were hospitalized for cure, which showed statistically significant level(P<0.05). 3. It was found that total 69 respondents(82.1%) were more or less satisfied with their medical aids depending on the causes of disability, and total 46 respondents(83.6%) were satisfied with their aids according to their handicap grade, but there were no statistical significance. 4. Total 56(66.7%) respondents answered that they would purchase medical aid on their own expenses, when they became handicapped. And the price of medical aid ranged from $\300,000{\sim}400,000$(25 respondents: 29.8%) to \ 500,000 or more(24 respondents: 28.6%). It means that they purchased more or less expensive medical aid on their own expenses, which showed statistical significance(P<0.05). 5. If there was any failure of medical aid, 9 respondents(37.5%) answered that they would be serviced from medical companies, and 7 respondents(29.2%) would be serviced from medical aid manufacturers. Most respondents were serviced for their medical aids from related companies. For the question about the causes of dissatisfaction upon repair service, 11 respondents(45.8%) answered that existing service company provided unskilled repair services and other respondents answered that there was no spare part or higher service expenses than they thought. These answers had the statistical significance(P<0.05). However, 20 respondents(79.2%) answered that they were satisfied with the repair service, which means that most respondents are satisfied with the service. In view of the results as described above, it can be concluded that their handicap or disability results from disease or sequelae after traffic accident and most of the affected wear their own medical aid. In the future, it is required that the medical insurance should cover those medical aids, and the service for failed medical aids should be commissioned by technical serviceman to realize customized manufacture and repair service according to different causes so that the handicapped can enjoy more or less comfort and convenience in their daily lives without any extreme difficulty.