• 한국건축시공학회지
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• 제21권3호
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• pp.231-239
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• 2021

4차 산업혁명 시대로 접어들면서 건설산업에서 CCTV, 홈네트워크시스템 및 장비와 같은 정보통신기술(ICT)이 활용되고 있다. 특히 공동주택에서 정보통신기술(ICT)의 자율성을 증대하기 위해 정부는 정보통신 관련법의 개정안을 행정예고하고 기업은 스마트 홈서비스와 같은 기술개발에 집중하고 있다. 또한, 정보통신공사 분야의 국내·외 연구는 대부분 정보통신기술(ICT)과 공사 관리에 관한 연구가 진행된 것을 확인할 수 있었다. 하지만, 정보통신공사의 품질에 영향을 주는 물리적 하자에 관한 연구는 부족한 실정이다. 이에 본 연구는 3개의 국내 건설사 프로젝트관리시스템에 등록된 하자 데이터를 수집하였고 공동주택관리법 시행령의 기준에 따라 분류하였다. 공종별 하자 빈도를 분석했을 때 홈네워크기기공사에서 하자가 88.10%로 가장 많이 발생하였다. 그리고 4개 공종의 하자 유형을 분석한 결과 작동불량이 가장 많이 나타났다. 그에 원인을 분석하고 설계·시공·유지관리 단계로 나누어 예방방안 및 대책을 제시하였다. 본 연구의 결과는 공동주택의 품질을 높이고, 추후 실질적인 하자 저감 대책 및 예방방안에 관련한 연구의 기초 자료로 활용될 수 있을 것이다.

• 전기학회논문지
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• 제60권6호
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• pp.1274-1279
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• 2011

The purpose of this paper is to present the manufacturing defect and damage pattern of a 3 phase 22.9/3.3kV oil immersed transformer, as well as to present an objective basis for the prevention of a similar accident and to secure data for the settlement of PL related disputes. It was found that in order to prevent the occurrence of accidents to transformers, insulating oil analysis, thermal image measurement, and corona discharge diagnosis, etc., were performed by establishing relevant regulation. The result of analysis performed on the external appearance of a transformer to which an accident occurred, the internal insulation resistance and protection system, etc., showed that most of the analysis items were judged to be acceptable. However, it was found that the insulation characteristics between the primary winding and the enclosure, those between the ground and the secondary winding, and those between the primary and secondary windings were inappropriate due to an insulating oil leak caused by damage to the pressure relief valve. From the analysis of the acidity values measured over the past 5 years, it is thought that an increase in carbon dioxide (CO2) caused an increase in the temperature inside the transformer and the increase in the ethylene gas increased the possibility of ignition. Even though 17 years have passed since the transformer was installed, it was found that the system's design, manufacture, maintenance and management have been performed well and the insulating paper was in good condition, and that there was no trace of public access or vandalism. However, in the case of transformers to which accidents have occurred, a melted area between the upper and the intermediate bobbins of the W-phase secondary winding as well as between its intermediate and lower bobbins. It can be seen that a V-pattern was formed at the carbonized area of the transformer and that the depth of the carbonization is deeper at the upper side than the lower side. In addition, it was found that physical bending and deformation occurred inside the secondary winding due to non-uniform pressure while performing transformer winding work. Therefore, since it is obvious that the accident occurred due to a manufacturing defect (winding work defect), it is thought that the manufacturer of the transformer is responsible for the accident and that it is lawful for the manufacture to investigate and prove the concrete cause of the accident according to the Product Liability Law (PLL).

• 한국건설관리학회논문집
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• 제20권5호
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• pp.104-114
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• 2019

본 연구는 부동산건설 관련된 대표적 소송인 도시정비사업의 시행주체인 조합설립과 관련된 소송의 승소요인에 대한 분석을 진행하였다. 이를 위해 조합설립인가 쟁송에 대한 전국의 제1심 행정법원 판결 441건을 분석대상으로 본안전항변사유와 본안전쟁점사항을 구분하여 계량법학적으로 승소확률표에 의한 빈도분석 및 계단식 예측방법에 의한 행렬표식 분석을 실행하였다. 인용률을 활용한 분석결과로 본안전항변사유와 관련하여 과거법률관계 항변, 인가고유하자아님 항변, 조합원지위 또는 소유권 없음 항변, 제소시간 도과 항변, 법률상이익 없음 항변 등, 본안쟁점사항과 관련하여 동의율하자산정, 동의서관련하자, 구역지정전승인, 총회관련하자, 구역지정하자 등의 순서로 빈도가 높은 것으로 파악되었다. 계단식 예측방식에 의한 행렬표식 분석을 통해 핵심예측변수인 '과거법률관계'와 '조합원지위 또는 소유권 없음'을 이용하여 본안승소판결에 미치는 영향을 분석하여 승패소구분을 위한 기준을 도출하였다. 이를 통해 도시정비사업에서 참여자별 소송결과의 예측가능성에 대한 이해도를 높이고 분쟁해결의 빈도를 낮춰 과다한 사회적 비용을 방지하는데 시사점을 제공하고자 한다.

• 한국안전학회지
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• 제33권5호
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• pp.28-34
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• 2018

Recently, various engineering approaches have been widely used in the accident investigation field to identify the cause of the accident and to predict damage by accident. Computational analysis is the most commonly used method of accident investigation technique. This technique is mainly used to identify the mechanism of the accident generation and to determine the cause when it is difficult to reproduce the situation at the time of the accident or when it is impossible to perform a reproduction experiment. In this study, The computational fluid dynamics analysis for nitrogen asphyxiation accident generated by defect of building structural between diffusion outlet and cooling tower was performed to determine the inflow path of the suffocation gas, death possibility by concentration of suffocation gas and predicted the time of death due to the accident using 3D modeling and FLACS program. We can quantify diffusion concentration of asphyxiation gas and predict mechanism of death occurrence by accident and evaluate the consequence Analysis through this study. In the future, This method can be widely used in the field of gas safety by improving the reliability and validity of the analysis.

• 한국안전학회지
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• 제33권3호
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• pp.1-7
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• 2018

Recently, various engineering approaches have been widely used in the accident investigation field to identify the cause of the accident and to predict damage by accident. Computational analysis is the most commonly used method of accident investigation technique. This technique is mainly used to identify the mechanism of the accident generation and to determine the cause when it is difficult to reproduce the situation at the time of the accident or when it is impossible to perform a reproduction experiment. In this study, The gas explosion analysis for LPG explosion accident generated by defect of the blocking action was performed to determine the accident object, gas leakage amount and predicted the damage caused by the accident using 3D laser scanner and FLACS program. We can quantify the explosive power by LPG gas accident and predict the gas leakage amount, damage by accident and evaluate the stability of the structure through this study. In the future, This method can be widely used in the field of gas safety by improving the reliability and validity of the analysis.

• Journal of mucopolysaccharidosis and rare diseases
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• 제2권1호
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• pp.13-16
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• 2016

Mucolipidosis (ML) II/III are autosomal recessive diseases caused by deficiency of post-translational modification of lysosomal enzymes. The mannose-6-phosphate (M6P) residue in lysosomal enzymes synthesized by N-acetylglucosamine 1-phosphotransferase (GlcNAc-phosphotransferase) serves as recognition marker for trafficking in lysosomes. GlcNAc-phosphotransferase is encoded by GNPTAB and GNPTG. Mutations in GNPTAB cause severe ML II alpha/beta and the attenuated ML III alpha/beta. Whereas mutations in GNPTG cause the ML III gamma, the attenuated type of ML III variant. For the diagnostic approaches, increased urinary oligosaccharides excretion could be a screening test in clinically suspicious patients. To confirm the diagnosis, instead of measuring the activity of GlcNAc phosphotransferase, measuring the enzymatic activities of different lysosomal hydrolases are useful for diagnosis. The activities of several lysosomal hydrolases are decreased in fibroblasts but increased in serum of the patients. In addition, the sequence analysis of causative gene is warranted. Therefore, the confirmatory diagnosis requires a combination of clinical evaluation, biochemical and molecular genetic testing. ML II/III show complex disease manifestations with lysosomal storage as the prime cellular defect that initiates consequential organic dysfunctions. As there are no specific therapy for ML to date, understanding the molecular pathogenesis can contribute to develop new therapeutic approaches ultimately.

• 한국생산제조학회지
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• 제24권4호
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• pp.463-468
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• 2015

High vibration of a low pressure (LP) turbine casing caused safety problems and life at the facility it was housed in. The main focus of this study was the cause of the high vibration in a low pressure turbine casing with manufacturing defects by frequency response analysis, compared with the results of experiments. Therefore, excited accelerations were obtained from the LP casing fundamental, and frequency responses were analyzed. The measurement and the modal analysis showed that the natural frequency of the LP turbine casing was 61.26 Hz and the excited frequency of the turbine rotor was 60.25 Hz. The manufacturing defect caused a decrease in the casing natural frequency and resulted in the high vibration of the casing because it moved close to the resonant frequency.

• Journal of Chest Surgery
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• 제16권2호
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• pp.175-183
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• 1983

Ventricular aneurysm which was first described by John Hunter on 18th century, has been experienced by many surgeons after successful using of cardiopulmonary bypass by Cooley on 1958. According to Gorlin, the definition of ventricular aneyrysm is portion of the ventricle which is not motile at systole (akinesis) or which has paradoxical dilatation at systole(dyskinesis). The ventricular aneurysm is classified to anatomical and functional. The anatomical ventricular aneurysm is devided into true or false again. Average age incidence is ranged from 49 to 60 and male predominance is reported. The cause is ischemic coronary artery disease in almost cases but hypertropoc cardiomyopathy, congenital abscence of myocardium, complication after mitral valvular replacement and trauma may also cause the ventricular aneurysm. Angina pectoris and congestive heart failure are most common clinical manifestations Ventricular tachycardia and systemic embolization are also complained. Using cardiopulmonary bypass, aneurysmectomy alone or combination with coronary artery revasculization are currently done for surgical treatment with steady improvenment of mortality. The first patient was 33 years old man who had true type of ventricular aneurysm on inferior wall the left ventricle near apex with protruded huge organized thrombus. The thromboembolic phenomenon was noted on both lower extremities. Under cardiopulmonary bypass, aneurysmectomy and thrombectomy were done. The aneurysmal orifice was repaired with Teflon buttless suture. The second patient was 30 years old female who had large true type of ventricular aneurysm on inferior wall of the left ventricle. Under cardiopulmonary bypass, aneurysmectomy with repair of aneurysmmal orifice defect by means of double layered Dacron patch was done with reinforce by outer silastic sheet covering. She was discharged from hospoital at post op. 15th day uneventfully.

• 한국압력기기공학회 논문집
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• 제8권3호
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• pp.7-12
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• 2012

Steam generator tubes are critical boundary of the primary and secondary side in nuclear power plants. Eddy current testing is commonly used as the method of non-destructive testing for the safety and integrity of steam generator tubes in the nuclear power plants. Changes in the geometric shape act as a stress concentration factor likely to cause a defect during the steam generator operation. The mixed-signals with the geometric shape are distorted and attributes that are difficult to detect signals. An example is bending stress due to compression process at a U-bend occurring in the intrados region which has a small radius of curvature. The resulting change in the geometric shape may lead to a dent like occurrences. The dent can cause stress concentration and generates stress corrosion cracks. In this study, the steam generator tubes of nuclear power plant were selected to study for analysis of mixed-signal containing dent and stress corrosion cracks.

• 한국소음진동공학회논문집
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• 제20권11호
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• pp.1025-1032
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• 2010

Gas turbine compressor blades used in a combined cycle power plant are possibly damaged and fractured during their operation. There are two possible causes of the failure of compressor blades; one is a defect of material quality which can be detected through some microscopic inspections for the fracture section, the other is high cycle fatigue problem caused by vibration and can be diagnosed by carrying out dynamic characteristics analysis for the blades. In this paper, in order to determine the cause of the failure of compressor blades in a combined cycle power plant, examination of the fracture section and the propagation mechanism of the crack via stress analysis are performed. Dynamic characteristics analysis via FRF estimation is also performed to identify the cause of failure.