• Journal of Acupuncture Research
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• 제24권1호
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• pp.111-125
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• 2007

Objection : The aim of this study was to investigate anti-ischemic effect of LR1 ${\cdot}$ HT8 ${\cdot}$ HT9 Reinforcement in Acupuncture. Methods : I designed to investigate whether LR1 ${\cdot}$ HT8 ${\cdot}$ HT9 Reinforcement in Acupuncture affects cerebral hemodynamics [regional cerebral blood flow(rCBF), pial arterial diameter(PAD), mean arterial blood pressure (MABP) ] in normal and cerebral ischemia rats by MCA occlusion method, and to make manifest whether LR1 ${\cdot}$ HT8 ${\cdot}$ HT9 Reinforcement in Acupuncture is mediated by cyclooxygenase or guanylate cyclase. The changes of rCBF and MABP were determinated by laser-doppler flowmetry(LDF), and the change of PAD was determinated by video microscope and width analyzer. Results: The results were as follows ; 1. LR1 ${\cdot}$ HT8 ${\cdot}$ HT9 Reinforcement in Acupuncture was significantly increased rCBF, PAD, but decreased MABP after withdrawing of the needle. This results suggest that LR1 ${\cdot}$ HT8 ${\cdot}$ HT9 Reinforcement in Acupuncture induced significantly rCBF by dilating PAD. 2. Pretreatment with indomethacin (1mg/kg, i.v.) was significantly inhibited LR1 ${\cdot}$ HT8 ${\cdot}$ HT9 Reinforcement in Acupuncture induced increase of rCBF and PAD, but increased LR1 ${\cdot}$ HT8 ${\cdot}$ HT9 Reinforcement in Acupuncture induced decrease of MABP after withdrawing of the needle. 3. Pretreatment with methylene blue(10/${\mu}$g/kg, i.v.) was decreased LR1 ${\cdot}$ HT8 ${\cdot}$ HT9 Reinforcement in Acupuncture induced increase of rCBF and MABP, but accelerated LR1 ${\cdot}$ HT8 ${\cdot}$ HT9 Reinforcement in Acupuncture induced decrease of PAD. This results suggest that the mechanism of LR1 ${\cdot}$ HT8 ${\cdot}$ HT9 Reinforcement in Acupuncture is mediated by cyclooxygenase or guanylate cyclase. Conclusion : I suggest that LR1 ${\cdot}$ HT8 ${\cdot}$ HT9 Reinforcement in Acupuncture has an anti-ischemic effect through the improvement of cerebral hemodynamics, and the mechanism IS mediated by cyclooxygenase.

• 한국압력기기공학회 논문집
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• 제18권1호
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• pp.11-18
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• 2022

When wall-thinning in a pipe occurs during operation of nuclear power plant, reinforcement of the pipe needs to be performed. Accordingly, the structural response of the piping system due to introduction of the reinforcement may be re-evaluated. For elastic structural analysis of the piping system with the reinforced pipe using finite element (FE) analysis, the stiffness of the reinforced pipe is needed. In this study, the stiffness matrix of wall-thinned pipe with pad reinforcement or composite reinforcement is analytically derived. The validity of the proposed equations is checked by comparing with systematic finite element (FE) analysis results.

• 한국공간구조학회논문집
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• 제23권1호
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• pp.45-52
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• 2023

This study proposes an RCS composite damping device that can achieve seismic reinforcement of existing buildings by dissipating energy by inelastic deformation. A series of experiments assessing the performances of the rubber core pad, hysteretic steel slit damping device, and hybrid RCS damping device were conducted. The results showed that the ratios of the deviations to the mean values satisfied the domestic damping-device conformity condition for the load at maximum device displacement in each direction, at the maximum force and minimum force at zero displacement, as well as the hysteresis curve area. In addition, three analysis models based on load-displacement characteristics were proposed for application to seismic reinforcement design. In addition, the validity of the three proposed models was confirmed, as they simulated the experimental results well. Meanwhile, as the shear deformation of the rubber-core pad increased, the hysteretic behavior of super-elasticity greatly increased the horizontal force of the damping device. Therefore, limiting the allowable displacement during design is deemed to be necessary.

• Carbon letters
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• 제4권3호
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• pp.117-120
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• 2003

Asbestos is being replaced throughout the world among friction materials because of its carcinogenic nature. This has raised an important issue of heat dissipation in the non-asbestos brake pad materials being developed for automobiles etc. It has been found that two of the components i.e. carbon fibres as reinforcement and graphite powder as friction modifier, in the brake pad material, can playa vital role in this direction. The study reports the influence of these modifications on the thermal properties like coefficient of thermal expansion (CTE) and thermal conductivity along with the mechanical properties of nonasbestos brake pad composite samples developed in the laboratory.

• Carbon letters
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• 제5권1호
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• pp.6-11
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• 2004

In spite of unparalleled combination of essential material properties for brake linings and clutch facings, replacement for asbestos is seriously called for since it is a health hazard. Once asbestos is replaced with other material then composition and properties of brake pad changes. In certain cases hardness of the material may be high enough to affect the rotor material. In this study, hardness of the brake pad has been controlled using suitable reinforcement materials like glass, carbon and Kevlar pulp. Brake pad formulations were made using CNSL (cashew net shell liquid) modified phenolic resin as a binder, graphite or cashew dust as a friction modifier and barium sulphate, talc and wollastonite as fillers. Influence of each component on the hardness value has been studied and a proper formulation has been arrived at to obtain hardness values around 35 on Scleroscopic scale. Friction and wear properties of the respective brake pad materials have been measured on a dynamometer and their performance was evaluated.

• 대한기계학회논문집A
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• 제40권3호
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• pp.245-252
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• 2016

본 논문은 벤드(bend)부의 노후 문제를 경감시키기 위한 대안으로 폼패드를 없앤 이중보온관의 형상 설계를 제안하였다. 전 관경에 대해 유한요소해석을 수행하였으며, 이를 토대로 전단제어링 형상을 결정하였다. 제안된 전단제어링 사양 강화이형관에 대한 현장 시공 시험은 진행하였으며, 온도와 응력 데이터를 취득 및 분석하였다. 강화이형관의 제작과 현장 시범시공을 통하여 강화이형관이 폼패드를 시공하지 않으면서도 강관의 열응력이 허용치 기준내에 있음을 확인하였다. 특히 보온재의 전단강도가 강화되어 폼패드를 적용한 기존 벤드보다 낮은 최대 전단응력이 발생함을 확인함으로써, 강화이형관 적용에 따른 구조 안전성 향상 효과를 확인하였다.

• 한국공작기계학회논문집
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• 제10권4호
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• pp.7-13
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• 2001

This Study is to investigate the influence of weld residual stresses on the fatigue crack growth behaviors in pressure ves-sel reinforcement. In order to perform this study, the automatically welded specimens are prepared. The material is ASTM A516 grade 60 steel used in pressure vessel mainly. For pad-on-plate of skip welding continuous welding and PWHT specimen, fatigue crack initiation is generally initiat-ed at weld starting and end toe zone, and ruptured at weld starting toe zone, Fatigue life if pad-on-plate continuous speci-men is increased more than that of pad-on-plate skip fillet welding specimene about 85% under low load, about 20% under high load, and decreased than that of two-pad continuous welding specimen about 85%. In da/dN-$\Delta$ Κ curve under low load, pad-on-plate skip fillet welding specimen showed retardation on the initial crack, and the fatigue crack growth rate at the low region of $\Delta$Κ greater specimene E(3.8{\times}10^{-6}$mm/cycle). And the fatigue life of welding specimen was smaller than that of PWHT specimen.

• 복식문화연구
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• 제31권6호
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• pp.738-755
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• 2023

The purpose of this study is to provide basic data for the production of jackets with high fit by comparing and analyzing the adhesive and non-adhesive production methods of men's jackets. An analysis of the manufacturing method showcased differences between the adhesive and non-adhesive manufacturing methods in the cutting and wick attachment method, the shape and attachment method of the chest reinforcing wick, the sleeve attachment method, and the shoulder pad and sleeve reinforcing cloth attachment method. In evaluating the outfit, the overall fit of the shoulder, the fit of the chest, and the fit of the armpit were found to be high in the non-adhesive production method. In evaluating appearance evaluation, the front shoulder, chest, and sleeve overall appearance showed a high non-adhesive production method. Therefore, in order to increase the wearability of the shoulder pad and the the attachment method of the upper sleeve reinforcing cloth, the non-adhesive production method should be used, and in order to increase the overall wearability and armpit wear of the chest, the difference in the attachment method, and the reinforcement method of the armhole should be used. In addition, to increase the appearance of the jacket, non-adhesive production methods such as differences in wick attachment methods, shoulder pads, sleeve reinforcing cloth, and sleeve attachment methods should be used.

• 한국구조물진단유지관리공학회 논문집
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• 제20권3호
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• pp.49-57
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• 2016

본 연구에서는 PSC I거더교에 대한 외부강선을 이용한 보강 방법 중 V자형 보강방식의 효용성을 검증하기 위하여 공용중인 교량을 대상으로 보강장치를 시공하여 보강효과를 분석하였다. 따라서 PSC I거더교의 보강 전과 후 각각의 경우에 대하여 정적 및 동적 재하실험을 실시하였다. 그리고 재하실험에서 측정된 결과를 면밀히 분석하고, 구조해석을 통해 얻은 결과와도 비교분석하여 외부 프리스트레스 도입을 통한 보강효과를 검증하였다. 본 연구에서 외부강선을 이용한 보강방법을 적용하여 보강효과를 검토한 결과, 본 연구에서의 V자형 외부강선 보강방법을 적용할 때 횡방향 하중분배계수 곡선이 완만해져 상부구조의 건전성이 증진됨을 알 수 있었으며, PSC I거더교의 휨 성능 및 전단 성능개선뿐만 아니라 동적구조거동에도 크게 도움을 줄 수 있는 것으로 판단되고, 본 연구에서의 탄성패드를 적용할 때 동적보강효과가 극대화 된다는 것을 확인하였다.

• 한국결정성장학회지
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• 제29권6호
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• pp.329-337
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• 2019

스플린터(splinter) 및 판상(plate shape) 형상을 가지는 티탄산칼륨염(K₂O·nTiO₂, PT)을 합성하고 브레이크 마찰재의 보강재로 이용하여 마찰 특성을 평가하였다. 스플린터형 티탄산칼륨염을 합성하기 위하여 먼저 판상 형상을 가지는 사티탄산칼륨염(K₂O·4TiO₂, PT4)을 합성하고 칼륨 이온(K⁺)을 일부 산침출(acid leaching)하여 육티탄산칼륨염(K₂O·6TiO₂, PT6)으로 변환시킨 후, 800℃에서 열처리하여 스플린터 형상의 입자를 얻었다. 판상형 티탄산칼륨염을 합성하기 위해서 염화칼륨을 융제로 사용하고 마그네슘(Mg)을 일부 첨가하여 판상의 형상을 가지는 마그네슘티탄산칼륨염(K_0.8Mg_0.4Ti_1.6O₄, PMT)을 합성하였다. 얻어진 육티탄산칼륨염 및 마그네슘티탄산칼륨염 입자를 보강재로 이용하여 브레이크 패드 마찰재를 제작하고 1/ 5-스케일 다이나모미터(scale dynamometer)를 이용하여 마찰 마모 특성을 평가하였다. 평가 결과, 두 종류의 보강재가 유사한 마찰계수 및 Fade & recovery 특성을 보였으며 판상형 마그네슘티탄산칼륨염의 경우, 스플린터형 육티탄산칼륨염보다 우수한 내마모성을 보이는 것을 알 수 있었다.