• Journal of the Korean Institute of Educational Facilities
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• v.23 no.6
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• pp.27-34
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• 2016

Although the scale and number of university facilities have increased, the maintenance of these facilities has not been efficient as maintenance costs incurred during facility operation periods, as well as management time, have not been sufficiently considered. In this study, the maintenance record data of national universities was compared and analyzed to analyze factors that incur maintenance costs according to the uses and costs of the facilities. According to the results, the number of cases of maintenance and repair work for basic educational facilities was shown to be the largest, accounting for 79%. The number of maintenance and repair work occurred according to work type was examined. According to the results, the highest ratio of maintenance and repair work occurred in the field of construction, specifically, the maintenance costs required for facility supplementation accounted for the highest ratio. Maintenance costs per unit area decreased over time in the newer university facilities, while showing a tendency to increase in older university facilities. However, there were cases where maintenance costs did not show any trends due to factors such as the limited maintenance budgets owing to the characteristics of public service facilities and facilities in the stage of deterioration or destruction after the stage of stabilization. This study is considered to be helpful for efficient university facility maintenance plans and budget calculations.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.1
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• pp.9-20
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• 2023

For highway concrete structures, the deterioration of the structure is accelerated due to the increase in the use of deicing materials, and sectional repair work is being frequently carried out to restore performance. However, after the repair work, re-damage such as cracks, delamination, and poor bond performance is exhibited in the repaired sectional area. In this study, overseas repair material requirements were first analyzed, and present domestic requirements were improved repair material performance through field surveys of common concrete structures, laboratory experiments, and test construction on a disused concrete bridge. In addition, performancebased quality requirements were presented so that all materials that meet the required performance can be applied, and different test methods for each material were unified into concrete test methods for consistent test results analysis. The considered performance requirements were compression strength, bending strength, and bond strength for structural properties, and length change rate, crack resistance, thermal expansion coefficient, and elasticity coefficient were for dimensional behavior. For resistance to chloride penetration resistance and freeze-thaw resistance were presented as durability. The proposed requirements for concrete repair materials are expected to contribute to the improvement of the quality of concrete sectional repair work in Korea.

• Journal of architectural history
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• v.29 no.6
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• pp.89-100
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• 2020

This paper sought to examine characteristics and differences of the construction methods and the materials of the wall repair by three command through individual command records and national documents. This paper is based on the management section of three commands(Samgunyoung), which was in charge of a repair and management of Hanyangdoseong(Seoul city wall) in 18th century. The purpose and background of the study are as follows. First, through each inscribed stones on the rampart and the parapet, it is to grasp accurately the point of change of Hanyangdoseng after the 18th century. Second, through inscribed stones, the site evidence of the repair work in the late Joseon Dynasty, it is to find out the aspects of the development process of repair and reconstruction technology of Hanyangdoseng.

• KIPS Transactions on Software and Data Engineering
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• v.10 no.9
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• pp.359-366
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• 2021

A number of construction companies in Korea invest considerable human and financial resources to construct a system for managing apartment defect data and for categorizing repair tasks. Thus, this study proposes machine learning models to automatically classify defect complaint text-data into one of the sub categories of 'finishing work' (i.e., one of the defect repair tasks). In the proposed models, we employed two word representation methods (Bag-of-words, Term Frequency-Inverse Document Frequency (TF-IDF)) and two machine learning classifiers (Support Vector Machine, Random Forest). In particular, we conducted both binary- and multi- classification tasks to classify 9 sub categories of finishing work: home appliance installation work, paperwork, painting work, plastering work, interior masonry work, plaster finishing work, indoor furniture installation work, kitchen facility installation work, and tiling work. The machine learning classifiers using the TF-IDF representation method and Random Forest classification achieved more than 90% accuracy, precision, recall, and F1 score. We shed light on the possibility of constructing automated defect classification systems based on the proposed machine learning models.

• Laser Solutions
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• v.15 no.1
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• pp.6-9
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• 2012

In TFT-LCD manufacturing process, various defects are generated by manufacturing machine trouble or particle. These defects can be repaired through the TFT-Laser repair process that only can't be automated in TFT-LCD manufacturing Process. In this Paper, we propose auto defect algorithm for TFT-LCD laser repair machine using image processing algorithm in order to automate process. Proposed algorithm can detect very small defects (< 2um) in 98% success ratio, and generated laser repair path guarantee highly precise position accuracy. Through proposed system, much of the work still done the old-fashioned way, by hand, can be automated and manufacturing company can be strengthed the competitiveness of cost.

• Journal of Korean Foot and Ankle Society
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• v.22 no.2
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• pp.68-73
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• 2018

Purpose: This study compared the clinical outcomes of open repair, percutaneous repair, and minimal incision repair by Achillon in ruptured Achilles tendon. Materials and Methods: The outcomes of 12 patients with open repair (group 1), 8 patients with percutaneous repair (group 2), and 10 patients with minimal incision repair by Achillon (group 3) from February 2013 to March 2016 were analyzed retrospectively. The postoperative clinical evaluations were done by the American Orthopaedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, Arner-Linholm scale, mid-calf circumference difference, one-leg heel raise difference, visual analogue scale (VAS) for postoperative scarring, time to return to work, and complications. Results: No significant difference in the AOFAS ankle-hindfoot score, Arner-Linholm scale, and time to return to work was observed among three groups (p=0.968, 0.509, and 0.585). The mean differences in the mid-calf circumference in groups 1, 2, and 3 were 1.09, 0.73, and 0.58, respectively; groups 2 and 3 were significantly higher than group 1 (p=0.002). In addition, the mean VAS scores for postoperative scarring in groups 1, 2, and 3 were 7.0, 9.1, and 9.1, respectively; groups 2 and 3 were significantly higher than group 1 (p=0.001). The mean differences in one-leg heel raising in groups 1, 2, and 3 were 2.03, 1.91, and 1.33, respectively; group 3 was significantly higher than groups 1 and 2 (p=0.010). The complications encountered were one case of deep infection in group 1 and one case of sural nerve hypoesthesia in group 2. Conclusion: Minimal incision repair by Achillon is recommended as an effective surgical treatment for Achilles tendon rupture because it minimizes the risk of complications, leads to an improved tendon strength and healing, and achieves cosmetic satisfaction.

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.1 s.53
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• pp.69-77
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• 2009

An underwater structure is made to put with serious damage state by special environmental factors. If this damage phenomena persist, as for the structure, it is generated a structural serious problem because of the corrosion of a reinforcing bar and the loss of the concrete cut end. Repair work of an underwater structure is very harder than repair work in land, and it is actual that certification about a maintenance effect is uncertain. And the existing repair method is applied to a structure damaged with you without verification of a repair effect by a foreign reward and experience. In this study, a repair method about an underwater structure was proposed and observed a behavior characteristic and interface failure of an specimens. and comparison analyzed an effect of a proposed maintenance method.

• Journal of architectural history
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• v.24 no.5
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• pp.33-40
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• 2015

The present study is aimed to reconsider the time of installation and the purpose of the square footstone located at the center of the wooden pagoda in Hwangnyongsa Temple, based on related precedent studies. Precedent studies are divided into two streams of assertions: one is that the square footstone was to support the major pillars at the time of building and the other is that it was installed to store Buddhist reliquaries inside the central foundation stone after the wood pagoda burnt down in the Invasion of Mongol. Summarizing the grounds with which the precedent studies support their assertions, they are the relation with Gaseopbul Yeonjwaseok, the emerging time of the square footstone, repairing work at the level of reconstruction, additional enshrinement of general Buddhist reliquaries and so on. The present study reviewed the key grounds suggested in the previous studies regarding the square footstone. First, it was determined that the square footstone has nothing to do with Gaseopbul Yeonjwaseok, after looking into the timings of appearance, condition and shape in literatures. Rather, it was assumed that Gaseopbul Yeonjwaseok resembles a stone column. Next, the square footstone is assumed to be installed after the 4th year of King Kwangjong's rule because the wood pagoda was lost in fire in the 4th year of Kwangjong's rule and it had been left alone for 68 years until the repair work finished in the 13th year of King Hyunjong. It is assumed that repair works at the level of reconstruction had been twice in total, say, once during King Kyungmun and Hyunjong, respectively. Next, looking into the establishment of the general Buddhist reliquaries and the repair work during King Kyungmun, it was not common then to enshrine additional Buddhist reliquaries when repair work progressed and so there was not an additional enshrinement of Buddhist reliquaries after King Kyungmun. However, it is hard to decide that there was no repair work at the level of reconstruction at that time. Last, we can find a similar case to the square footstone of the wood pagoda in Hwangnyongsa Temple in the copper pagoda in Japanese Yaksasa Temple. In conclusion, it is assumed that the wooden pagoda in Hwangnyongsa Temple was lost to the fire in the 4th year of King Kwangjong's rule and thus the square footstone had been used as Jinho stone to protect Buddhist reliquaries and used as a propping stone for the major pillars after King Hyungjong.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.66-67
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• 2015

This study compared and analyzed the job importance that site managers perceived by dividing the study scope into customized and expansion remodeling projects and deriving the job descriptions from previous studies. As a result, a total of 7 construction stages and 53 job descriptions were derived. As job importance in customized remodeling projects, removal and demolition works were the most important, followed by preliminary survey, and repair and reinforcement works. In addition, as job importance in expansion remodeling projects, preliminary survey is the most important, followed by civil engineering work, and repair and reinforcement works. It is considered that the job importance of the remodeling projects derived in this study will contribute to improving their job efficiency in the future.

• Structural Engineering and Mechanics
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• v.88 no.3
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• pp.201-208
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• 2023

In this work, the effect of the correction fibers direction on the efficiency of repairing damaged composite plates was highlighted. The composite plates studied in this work consist of eight layers of graphite/epoxy, while the patch used in this repair consists of four layers of the same type. The results obtained in this work, whether with regard to the experimental or analytical side, showed that the fibers orientation affects the repair efficiency, so the closer the angle of fibers inclination is to the tensile strength direction, the performance of the composite material is ideal. Hence, we conclude that the composite materials with longitudinal fibers (Parallel to tensile strength) is the most powerful and efficient material in performance.