• 대한치과교정학회지
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• 제30권1호
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• pp.67-82
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• 2000

치아의 맹출장애에 관한 연구들은 많은 경우 치아의 유착이나 물리적인 장애에 의한 영구치의 맹출지연, 매복 등을 다루어 왔다. 그러나 치아의 맹출장애는 단순히 국소적이며 물리적인 현상일 수도 있지만 전신적 발육이상의 발현일 가능성도 높음을 간과해서는 안 된다. 이는 중요한 전신질환의 일부 현상으로 나타나는 경우가 많으며 맹출기전 자체에 이상이 있는 경우도 있다. 특히 영구치의 맹출장애는 치열 및 악골의 발육에 영향을 미치고 치주조직의 손상을 야기하며 기능장애 및 심미적인 문제를 가져올 수 있다. 그러므로 정상적인 치아의 맹출은 악안면의 성장과 발육,기능에 중요하다고 할 수 있다. 따라서 교정임상의로서 우리는 치아의 맹출에 이상이 있는 환자를 조기에 진단, 발견하여 그 원인을 밝히고 이에 따라 적절히 대처할 수 있는 능력을 가져야 할 것이다. 본 연구에서는 치아의 맹출장애를 일으키는 윈인요소 및 이에 따른 치료방법의 차이에 대해 알아보고 그 중 골형성 부전증 및 primary failure of eruption환자를 예로 들었다.

• 디지털융복합연구
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• 제15권8호
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• pp.69-83
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• 2017

본 연구의 목적은 갤럭시노트7의 예를 들어 신제품의 실패를 시스템 안전분석 기법을 활용해 체계적으로 분석하는 것이다. 이러한 분석을 통해 제품실패의 근본적인 원인을 찾고 그 원인으로 발생하는 문제를 해결함으로써 사건재발을 방지하는데 도움이 되는 정보를 제공하고자 한다. 이를 위해 제품실패를 단순히 기술적 실패로 바라보는 것이 아니라 제품개발과 경영관리가 포함된 하나의 통합 시스템으로 바라보며, 그에 대한 실패의 근본적인 원인들을 분석할 필요가 있다. 이러한 관점을 갖고 시스템 안전분석 기법인 근본원인분석과 고장수목분석을 활용해 갤럭시노트7의 제품실패 원인을 분석하였다. 이러한 분석과정을 통해 배터리 과열이라는 피상적인 기술적 문제와 더불어 경쟁사와의 지나친 경쟁에 따른 무리한 제품출시와 성과주의와 같은 제품개발 및 경영관리에서의 문제에도 많은 관심을 기울일 필요가 있음을 파악하였다. 또한 통합 시스템적 관점을 견지한다면 제품실패의 원인을 분석하는데 근본원인분석과 고장수목분석이 유용하게 이용될 수 있음을 확인할 수 있었다.

• 터널과지하공간
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• 제19권2호
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• pp.95-106
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• 2009

암석파괴역학과 파괴인성 이하의 응력상태에서 균열이 발생하고 성장하는 특성을 고려하여 암반사면의 진행성 파괴를 검토하였다. 굴착이 종료된 암반사면은 응력이 거의 변하지 않은 조건이지만, 시간이 경과함에 따라 절리면 내 미소한 접점에서 파괴가 발생하고 파괴된 접점의 수효가 증가함에 따라 절리면이 파괴되고, 파괴된 절리면이 많아져 사면이 파괴되는 진행성파괴 현상을 수치해석적으로 확인하였다. 따라서 암반사면의 진행성 파괴는 파괴인성보다 낮은 응력상태에 있는 암반 절리면 내 미소한 접점에서 시간의 경과에 따라 발생한 균열이 성장하여 사면을 파괴시키는 것으로 분석되었다.

• 품질경영학회지
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• 제47권3호
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• pp.571-582
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• 2019

Purpose: To develop a risk metric for failure cause that can help determine the action priority of each failure cause in FMEA considering time sequence of cause- failure- detection. Methods: Assuming a quadratic loss function the unfulfilled mission period, a risk metric is obtained by deriving the failure time distribution. Results: The proposed risk metric has some reasonable properties for evaluating risk accompanied with a failure cause. Conclusion: The study may be applied to determining action priorities among all the failure causes in the FMEA sheet, requiring further studies for general situation of failure process.

• Clinical and Experimental Reproductive Medicine
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• 제25권3호
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• pp.281-286
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• 1998

Premature ovarian failure is a condition causing amenorrhea, hypoestrogenism, and elevated gonadotropins in women younger than 40 years. Many causes of premature ovarian failure were reported, including genetic abnormalities, enzymatic defects, defects in gonadotropin secretion or action, autoimmune disorders, physical and idiopathic causes. Recently, Finnish group reported a point mutation in the follicle stimulating hormone (FSH) receptor gene in premature ovarian failure patients. But it was reported that the group from United States could not find any mutation in FSH receptor gene. So we analysed C566T point mutation of FSH receptor gene using restriction fragment length polymorphism (RFLP) and compared the result between premature ovarian failure patient with idiopathic and known causes. But we did not find 556C${\rightarrow}$T mutation in the FSH receptor gene in both groups. These findings suggest that the missense mutation in the human FSH receptor gene reported in Finnish women with premature ovarian failure is uncommon in Korean women with premature ovarian failure.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2005년도 후기학술대회논문집
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• pp.222-223
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• 2005

The Any failure of piston of marine diesel engine must be regarded as serious, and any steps which can be taken to prevent such failure are desirable. The purposes of this study is to investigate and to analyse the failure causes of piston of marine diesel engine. If this paper has accomplished that end it can be counted as being of some slight value to the marine industry.

• Clinical and Experimental Pediatrics
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• 제50권10호
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• pp.948-953
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• 2007

Acute renal failure is the generic term for an abrupt and sustained decrease in renal function resulting in retention of nitrogenous and non nitrogenous waste product. This may results in life threatening consequences including volume overload, hyperkalemia, and metabolic acidosis. Acute renal failure is both common and carries high mortality rate, but as it is often preventable, identification of patients at risk and and appropriate management are crucial. This review summarized the most recent information on definition, epidemiology, clinical causes and management of acute renal failure in pediatric patients.

• 상하수도학회지
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• 제10권1호
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• pp.96-111
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• 1996

The failure of water pipelines is progressed by several compound factors and the collection and analysis of data about pipeline failure are inevitable for effective pipeline rehabilitation. Data analysis of pipeline failure was already performed in USA and Europe. Based on such phenomena, failure characteristics about metropolitan pipelines in Korea were analyzed: The conclusions of this study are as followings. 1. The failure cause of pipelines can be classified into natural cause and artificial cause. Artificial cause is 32% of total causes, so artificial failure as several constructions happens frequently in Korea. Although the failure by old pipe is greatest of any other causes m classtfied cause, failure cause is not classified in detail now. 2. The damaged part of pipelines is affected by cities, distribution system inventory, bedding conditions, and so on. In this study, the failure of pipeline body(67%) is greater than the failure of pipeline joint(33%) in natural failure. 3. In regard to pipe materials, failure rate of DCIP(0.8456), PEP(0.7288), and GSP(0.6643) is greater than that of CIP(0.3985) and CWSP(0.2348). 4. Usually, faIlure rate is increased in proportion to diameter of pipeline. In this study, CIP, DCIP, and CWSP have clear trends. But the trends of PEP is reverse, the case of GSP, HP is obscure due to data shortage. 5. There are no direct relationships between burial age and failure rate of pipelines. 6. Annual breaks and winter(Nov.~Feb.) breaks of pipelines are investigated. As a result, WInter breaks to annual breaks of CIP is 51.3%(Seoul), 51.1%(Taegu),38.7%(Pusan). This phenomena have direct correlation with average winter temp. of cities.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.1237-1243
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• 2005

International construction projects are exposed to various and complicated risk factors stemming from different political, economical, social, and cultural backgrounds, which make contractors entering into international construction to experience severe losses. It implies that overseas markets do not necessarily secure the high return, which is typically expected to in the high risky attempts. Accordingly, contractors need to evaluate various risk factors faced with overseas construction projects that can possibly aggravate the profitability. This paper aims at establishing a valid groundwork for further research on developing the integrated risk management model. For this end, it analyzes the long-term trend of profitability on total of 3,487 projects performed by Korean global contractors in world-wide construction markets during the last four decades. Then, it investigates the possible factors/causes of bad profit that have affected the profitability significantly through the structured surveys of 90 real overseas projects based on the project-specific information and experiences of Korean contractors in overseas markets. Furthermore, it analyzes relative importance of these factors/causes and identifies the important features expected for the risk management of international construction projects. Finally, vital distinctions between success and failure projects and lessons learned to improve profitability are then distilled.

• The Journal of Advanced Prosthodontics
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• 제4권2호
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• pp.76-83
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• 2012

PURPOSE. Zirconia has been used in clinical dentistry for approximately a decade, and there have been several reports regarding the clinical performance and survival rates of zirconia-based restorations. The aim of this article was to review the literatures published from 2000 to 2010 regarding the clinical performance and the causes of failure of zirconia fixed partial dentures (FPDs). MATERIALS AND METHODS. An electronic search of English peer-reviewed dental literatures was performed through PubMed to obtain all the clinical studies focused on the performance of the zirconia FPDs. The electronic search was supplemented by manual searching through the references of the selected articles for possible inclusion of some articles. Randomized controlled clinical trials, longitudinal prospective and retrospective cohort studies were the focuses of this review. Articles that did not focus on the restoration of teeth using zirconia-based restorations were excluded from this review. RESULTS. There have been three studies for the study of zirconia single crowns. The clinical outcome was satisfactory (acceptable) according to the CDA evaluation. There have been 14 studies for the study of zirconia FPDs. The survival rates of zirconia anterior and posterior FPDs ranged between 73.9% - 100% after 2 - 5 years. The causes of failure were veneer fracture, ceramic core fracture, abutment tooth fracture, secondary caries, and restoration dislodgment. CONCLUSION. The overall performance of zirconia FPDs was satisfactory according to either USPHS criteria or CDA evaluations. Fracture resistance of core and veneering ceramics, bonding between core and veneering materials, and marginal discrepancy of zirconia-based restorations were discussed as the causes of failure. Because of its repeated occurrence in many studies, future researches are essentially required to clarify this problem and to reduce the fracture incident.