• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
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• pp.551-552
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• 2009

오늘날 건축시공에 있어 하자발생 가능성이 증가하고 있다. 이에 부실공사 방지를 위해 건설 안전 정책이 시행되고 있지만, 하자 관련 규정이 추상적이고 불확실하게 규정되어 있어 하자와 관련 된 분쟁은 나날이 증가 되고 있다. 이에 본 연구에서는 하자의 유형 및 원인을 분석하고, 이에 대한 하자책임 및 하자담보 책임기간에 대한 분쟁의 합리적 해결책을 제시하기 위하여 관계 전문가들을 대상으로 설문조사를 실시하였다.

• 한국전기전자재료학회논문지
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• 제14권7호
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• pp.578-583
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• 2001

The bushing for high voltage and large and power should endure weight of itself and force of pushing from contact with circuit breaker. Like this, epoxy mold bushing has to be strong without fault. However, the external circumstances and internal factors was caused by partial discharge, flashover and dielectric breakdown. Therefore, to remove external factor of defect and to prevent the internal cracks and cavity generated from the contraction on interface of Cu-Epoxy, we should form semi-conductive layer on Cu bar by carbon. Then, the PD properties and the insulation qualities of epoxy mold type bushing was able to improved by roles of cushions for the direction of diameter and by effects fo natural sliding like as separated from conductor for the direction of length. So, in this work, we could prove the method of semi-conductive layer in making the long conductor.

• Carbon letters
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• 제11권2호
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• pp.102-106
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• 2010

In this work, the effect of aminized multi-walled carbon nanotubes (NH-MWNTs) on the mechanical interfacial properties of epoxy nanocomposites was investigated by means of fracture toughness, critical stress intensity factor ($K_{IC}$), and impact strength testing, and their morphology was examined by scanning electron microscope (SEM). It was found that the incorporation of amine groups onto MWNTs was confirmed by the FT-IR and Raman spectra. The mechanical interfacial properties of the epoxy nanocomposites were remarkably improved with increasing the NH-MWNT content. It was probably attributed to the strong physical interaction between amine groups of NH-MWNTs and epoxide groups of epoxy resins. The SEM micrographs showed that NH-MWNTs were uniformly embed and bonded with epoxy resins, resulted in the prevention of the deformation and crack propagation in the NH-MWNTs/epoxy nanocomposites.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1995년도 Proceedings of the Korea Automation Control Conference, 10th (KACC); Seoul, Korea; 23-25 Oct. 1995
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• pp.142-145
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• 1995

It is important from prevention of the malfunction and an important accident by the failuer, to detect a failuer in revolution devices. The acoustic emission(AE) method is expected as means that defects an abnormal phenomenon of revolution devices earlily and utilized. Although a research example by the AE method is reported regarding a gears, little reserch has been conducted using the AE method for running gears in a bending fatigue process of spur gear teeth. Therefore, in this report, with two micro AE sensors attached to the side of the gear, AE was measured in a bending fatigue process of a carburizing gear by using the power circurating-type machine and AE source location in gear teeth were required. By various analysis in these data, the AE characteristics in the fatigue damaging process of the gear tooth were determined.

• 자동차안전학회지
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• 제6권2호
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• pp.36-42
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• 2014

In order to prevent the sharp edge during the side impact, a cause analysis and CAE based risk prediction were carried out in this study. It was found that sharp edge occurs mainly because of stiffness difference between the major parts and structural stress concentration. It could be improved by directly reinforcing the crack initiation region or by weakening the joints connecting the parts. The fracture criterion based on major in-plain strain was suggested and the risk prediction process for sharp edge prevention was established.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1996년도 International Conference on Agricultural Machinery Engineering Proceedings
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• pp.238-246
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• 1996

When the important structures or components of agricultural machinery are designed, the full-filed methods of stress analysis can provide enough information in order to obtain lighter weight and prevent failure. The photoelasticity has been applicated to solve many practical engineering problems. The coating method provides full-field information, enabling the engineers to determine the complete distribution of surface strains and directly highlighting severely strained areas, especially for the welded frames of agricultural machinery. A combined method of model and prototype for strain analysis of excavator has been successfully applied to improve design. A measuring and recording system controlled by micro-computer and application software for dynamic event was studied. It can be widely used in structural failure analysis under cyclical loading . Typical application concerned stress field of crack tip and failure analysis of some mechanical structures are introduced are in roduced briefly in this paper.

• 한국재료학회지
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• 제7권1호
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• pp.15-20
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• 1997

목재의 건조 균열방지를 위한 진공흡입기술의 새로운 목재처리방법에 대해 연구를 수행하였다. 목재의 건조균열 방지를 위해 사용된 ployetylene grycogen(PEG) 처리재들은 PEG-1540, PEG-2000, PEG-4000, PEG-10000이었으며, 진공펌프의 감압정도는 85kPa과 39kPa 이었다. 시험결과, 진공흡입처리에 의한 PEG액의 흡입은 방사단면에 걸쳐 고르게 이루워졌음을 확인 할 수 있었다. 또한 PEG의 분자량이 증가할수록 단위시간당 PEG의 분자량이 증가할수록 단위시간당 PEG의 흡입량과 처리전.후의 함수률의 차인$\Delta$ M.C 는 PEG-2000을 변곡점으로 하여 감소하였다. 그리고 리기다 소나무의 건조균열 방지를 위한 약제 흡입처리에 있어 최적의 PEG 분자량과 농도 그리고 감압력의 조건은 각각 PEG-2000과 30%(wt.)그리고 85kPa임을 알 수 있었다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표대회 논문집(III)
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• pp.916-921
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• 1998

This study describes the result for the placement of the super flowing concrete(SFC) in under-pinning-top-slab which is located Inchon subway section 1-10 where, due to heavy reinforcements and limited working space, it was difficult to place concrete. After placing 600㎥, smooth construction and quality control were possible due to the good flow-ability, self-fillingability, and the resistance of segregation of the SFC itself. Furthermore, economical efficiency was obtained through not only the reduction of the works, labors, and site noise but also the efficient construction control. Because of the crack prevention, high strength, and a fine concrete surface, this study could be considered as a momentum to be adopted generally for applying the proposed method to the difficult subway construction area in the near future.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 춘계 학술논문 발표대회
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• pp.188-189
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• 2019

In this study, the characteristics of single-component and other sealant were analyzed to provide repair methods and effective utilization of sealant due to crack generation. Humidity studies have shown that acrylic silicone is effective in many areas of fluidity and temperature change, and that polysulfide-silicon is most effective in resistance to linear expansion coefficient and external pressure. Therefore, the difference between drying shrinkage and thermal expansion coefficient between various building materials and sealant, as well as the use of sealant, is analyzed, and construction methods derived accordingly, and prevention of defects are considered to be part of the construction project.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2017년도 추계 학술논문 발표대회
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• pp.30-31
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• 2017

The objective of this study is to evaluate the performance of polymer-modified surface preparation mortars with pozzolanic materials for corrosion prevention method in deteriorated sewage treatment structures. The prepackaged-type surface preparation mortars are prepared with a polymer-binder ratio of 10%, ground granulated blast furnace slag contents of 0, 15, 30%, a fly ash content of 15%. And, the specimens are tested for workability, adhesion in tension, water absorption, crack and impact resistance. As a result, the prepackage-type surface preparation mortars for sewage treatment structure are satisfied with quality requirements by KS F 4716, Japan sewage work agency(JS) and JIS A 6916 for surface preparation mortars.