• Journal of the Korea Institute of Building Construction
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• v.24 no.1
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• pp.55-66
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• 2024

This research addresses the types and causes of defects in seismic retrofitting projects of school facilities, which, following the Gyeongju and Pohang earthquakes in September 2016 and November 2017 respectively, have been identified as having comparatively lower seismic resilience among public buildings. The incidence of seismic retrofitting has notably increased in the subsequent years, raising concerns about the potential for defects arising from these efforts. The government has committed to enhancing the seismic resilience of all public facilities by 2035, with a specific focus on completing upgrades for educational establishments by 2029. Although prior investigations have explored construction defects in school facilities, there exists a gap in research specifically targeting defects within seismic retrofitting processes. Thus, this study aims to catalog the defects associated with seismic retrofitting efforts and analyze their underlying causes to identify crucial management strategies for defect mitigation. Furthermore, by examining the interplay between defect types and their causative factors, the study seeks to pinpoint essential management practices that could preempt defects during the construction phase, ultimately aiding in the reduction of future maintenance expenditures.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.11
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• pp.510-519
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• 2019

The aim of this study was to set a defect classification framework and evaluate the defect risks in apartment buildings For this, approximately 15,056 defect items for 133 apartment buildings were examined. As a result of the analysis, the major defect of the RC work was cracks, which were found mainly in public locations. Moreover, the RC work was found to exhibit a high defect risk of water problem and surface appearance, which are highly connected with cracks. Second, the finish work has a high defect risk because it is composed of various work types, and there are many kinds of materials and construction parts involved. Third, the major defects of the waterproof work were incorrect installation and missing tasks, which have high defect risks in the garage. This is because defects that require rework occur mainly in the underground garage. Based on these results, this study proposed countermeasures for defect risk management to be considered in the construction, handover, post-handover, and occupancy phases. These have been set in detail based on the three zones: low frequency high severity (LFHS), low frequency low severity (LFLS), and high frequency low severity (HFLS).

• Journal of the Korea Institute of Building Construction
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• v.11 no.3
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• pp.208-220
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• 2011

Recently, the arbitration system for defect disputes has been introduced to settle the disputes arising from defects in apartment buildings. However, the conciliation system did not reflect the current technical issues of defect disputes and the opinions of each party involved in the disputes. Moreover, it revealed more imperfections in the content and the process of the system itself. Therefore, this study aims to review the technical aspects of defect disputes, and suggest an alternative to the conventional conciliation system. This paper also discusses logical factors that can be addressed for the current subjective judgment. It is recommended that each party involved in the defect dispute build mutual trust in order to meet social needs, which is the underlying support for the revitalization of the institutional level.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.44 no.1
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• pp.60-70
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• 2021

Recently, with the development of technologies for the fourth industrial revolution, convergence and complex technology are being applied to aircraft, electronic home appliances and mobile devices, and the number of parts used is increasing. Increasing the number of parts and the application of convergence technologies such as HW (hardware) and SW (software) are increasing the No Defect Found (NDF) phenomenon in which the defect is not reproduced or the cause of the defect cannot be identified in the subsequent investigation systems after the discovery of the defect in the product. The NDF phenomenon is a major problem when dealing with complex technical systems, and its consequences may be manifested in decreased safety and dependability and increased life cycle costs. Until now, NDF-related prior studies have been mainly focused on the NDF cost estimation, the cause and impact analysis of NDF in qualitative terms. And there have been no specific methodologies or examples of a working-level perspective to reduce NDF. The purpose of this study is to present a practical methodology for reducing NDF phenomena through data mining methods using quantitative data accumulated in the enterprise. In this study, we performed a cluster analysis using market defects and design-related variables of mobile devices. And then, by analyzing the characteristics of groups with high NDF ratios, we presented improvement directions in terms of design and after service policies. This is significant in solving NDF problems from a practical perspective in the company.

• Journal of Korean Society for Quality Management
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• v.28 no.4
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• pp.1-15
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• 2000

Nowadays, consumers' consciousness on me quality are very diversified and their pattern is changing from the price-priority to me quality-priority. So they prefer good-quality products without defects. Therefore quality is a core competence. To compete with me facts, it is very important to keep me the quality competence. To do so, one way is to introduce 100ppm quality innovation system. Many corporates introducing 100ppm improved defect rations(not only process defect ratios but also product defect ratios). In these respects, this study focuses on the comparison and measurement of performance by the analysis of quality system between 100ppm corporates and non-100ppm corporates. Second, this focuses on the finding out core competence reinforcement factors according to the introducing of 100ppm quality system to improve the performance. Third, this focuses on the persuading to introduce the 100ppm quality system to the non-100ppm corporates. Last, this focuses on the playing on the role of guidance to improve QM efficiency.

• Journal of Yeungnam Medical Science
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• v.9 no.2
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• pp.422-426
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• 1992

One case of Congenital Cutis Aplasia is presented. The defect involved includes full-thickness skin defect of scalp and cranium. The patient was treated with debridement of dirty necrosed crust which covered exposed dura mater and with double opposing rotation flap including pericranium for bone regneration. The donor site was covered with skin graft from right thigh. During operation, the superficial temporal arterty was found to be short and weak. And after operation, the margin of flap were congested and finally necrotized. The necrotic wound was treated with conservative management. The vascular impairment is thought to be main course of Congenital Cutis Aplasia. So we conclude that the treatment of choice is conservative management or careful flap surgery for coverage of defect area.

• Proceedings of the Safety Management and Science Conference
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• 2004.05a
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• pp.283-289
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• 2004

The number of pixel defects including bright and black dots on a panel is one of the critical factors determining the quality of TFT-LCD. Since pixel defects on the TFT-LCD panels are sometimes unavoidable, manufacturers have to inspect the panels so that any panel with an unacceptable number of defects will not be delivered to the buyers. However, the buyers demand for the manufacturers to meet different pixel defects tolerances (acceptable number of pixel defects on a TFT-LCD panel) around central(tight) and peripheral(loose) inspection zones. The disagreement in quality standard among different buyers also cause confusions in screening non-confirmative products and unstable yield of production. Few research has focused on the effects of defect locations on a TFT-LCD panel on their detection probabilities and the rational division of defect inspection zones. In this research, experiments were conducted to find the detection probabilities of black dot defects with respect to their varying locations on a TFT-LCD. It is proposed a rational division of inspection zone on a TFT-LCD panel on the basis of detection probabilities of the defects. With these division of inspection zones and the mean defect detection probability within each zone, it is expected to establish a more reasonable pixel defects tolerances.

• International conference on construction engineering and project management
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• 2011.02a
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• pp.629-635
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• 2011

Retentions are generally considered to be intended to act as a powerful tool to incentivize contractors/subcontractors to remedy defective work in cases of non-performance. This study attempts to establish the extent to which retentions can be used for this purpose by investigating case law connected with insurance and defective work. One of the significant questions is whether retentions are sufficient to deal with construction defects or value of retentions in the rectification of defects is illusory. The cost to repair a defect may vary depending on a number of components including type, cause, magnitude and the construction stage at which the defect occurs. It is expected that a review of existing cases on defective workmanship will provide an insight on the issues and whether retentions are effective in their intended function. In order to establish their functionality, the study described in this paper investigated 6 construction insurance cases to identify the critical issues and the causes of dispute. It was found that the nature and the cause of defects were different in each case. It was also established that certain defect types not covered by insurance may be covered by retentions - potentially one of the key uses of a retention strategy. It is expected that the findings will assist in forming a view on the quantum of money that may be required paving the way for a first time understanding on a rational basis for setting up retention regime.

• Journal of Korean Society for Quality Management
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• v.38 no.3
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• pp.340-353
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• 2010

Properly designed and well-executed services enable e-commerce companies to capture the unique needs and preferences of customers, help them build customer loyalty, and thereby, strengthen their competitiveness in the marketplace. An object of this study is the new open-market company and it has only 3 percent of the market share. Therefore, it is needed to raise the market share by improving the service qualities. This article presents a six sigma project for service quality improvement in the open-market company. This study was carried out based on five steps of DMAIC which is six sigma technique. First, a defect rate was defined as unsatisfaction rate. In addition, 50-people data was analyzed and it was shown that the defect level was 2.5 sigma level. In this study, in order to raise the sigma level, novel eight action items were determined based on SIPOC, FDPM, cause and effect diagram, matrix chart, Pareto chart and statistical analysis.

• The korean journal of orthodontics
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• v.48 no.2
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• pp.113-124
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• 2018

The purpose of this case report was to introduce the concept of orthodontic and orthopedic treatment for a growing patient with Tessier number 0 cleft. A 5-year-old boy patient with Tessier number 0 cleft presented congenitally missing maxillary central incisors (MXCI), a bony defect at the premaxilla, a constricted maxillary arch, an anterior openbite, and maxillary hypoplasia. His treatment was divided into three stages: management of the bony defect at the premaxilla and the congenitally missing MXCIs using a fan-type expansion plate, iliac bone grafting, and eruption guidance of the maxillary lateral incisors into the graft area for substitution of MXCIs; management of the maxillary hypoplasia using sequential facemask therapy with conventional and skeletal anchorage; and management of the remaining occlusal problems using fixed orthodontic treatment. The total treatment duration was 15 years and 10 months. Class I canine and Class II molar relationships and normal overbite and overjet were achieved at the end of treatment. Although the long-term use of facemask therapy resulted in significant protraction of the retrusive maxilla, the patient exhibited Class III profile because of continued mandibular growth. However, the treatment result was well maintained after 2 years of retention. The findings from this case suggest that interdisciplinary and customized approaches are mandatory for successful management of maxillary hypoplasia, bony defect, and dental problems in Tessier number 0 cleft. Moreover, considering the potential of orthognathic surgery or distraction osteogenesis, meticulous monitoring of mandibular growth until growth completion is important.