• 제목/요약/키워드: reduce the damages

검색결과 400건 처리시간 0.029초

진동제어 콘크리트 패널의 제진성능 평각에 관한 실험적 연구 (Experimental Evaluation for Vibration Reduction Capability of Vibration-Controlled Concrete Panels)

  • 최우성;박용구;조성호;정영수
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1997년도 가을 학술발표회 논문집
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    • pp.351-356
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    • 1997
  • With the aid of advanced structural engineering, the construction of infrastructures has been recently accelerating to keep up with rapid economic growth. Construction activities and operation of transportation facilities cause civil petitions associated with vibration-induced damages or nuisances. As part of the decrease of vibration induced damage, the objective of this study is to develop vibration-controlled concrete with vibration-reduced materials, which can be recycled from obsolete materials, such as aged tires, plastics and etc. Appropriate mix proportion has been used for making 10 reinforced concrete panels with vibration-reduced materials, which have been tested to investigate on vibration reduction capability, based on the time and frequency domain analysis, and vibration velocity level analysis. Vibration-reduced mixtures are latex, styrofoam, rubber powder and plastic resin, which have been determined to by reduce vibration.

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퇴축이 심한 하악구치부에서 양측성 하치조신경 전위술을 이용한 인공치아의 식립

  • 손동석;이수경;박도영
    • 대한치과의사협회지
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    • 제37권4호통권359호
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    • pp.279-286
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    • 1999
  • In patients with severely atrophic mandibular posterior area, implant placement is a problematic surgical procedure. Inferior alveolar nerve transpositioning technique offers better initial stability of implant and reduce the risk of permanent nerve damages. In this case report, the patient has bilateral atrophic mandibular posterior edentulous area. We placed 3 implants on each mandibular posterior area in conjunction with bilateral inferior alveolar nerve transpositioning to achieve sufficient bone height. The patient complained of paresthesia in lower lip and chin area and ptosis of lower lip after surgery. Neurosensory function was normal in 10 weeks after surgery.

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Reduction of seismic pounding effects of base-isolated RC highway bridges using MR damper

  • Sheikh, M.N.;Xiong, J.;Li, W.H.
    • Structural Engineering and Mechanics
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    • 제41권6호
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    • pp.791-803
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    • 2012
  • Significant structural damages due to pounding between adjacent superstructures of multi-span reinforced concrete (RC) highway bridges have been observed in past earthquakes. Different methods have been proposed in the literature to mitigate the adverse seismic pounding effects. This paper presents an analytical investigation on the use of magnetorheological (MR) dampers in reducing seismic pounding effects of base-isolated multi-span RC highway bridges. It has been observed that MR damper can effectively reduce the seismic pounding effect. Three control strategies (passive off, passive on, and bang bang control) of MR damper have been investigated. Although all the control strategies are found to be effective, bang bang control has been observed to be the most effective.

DCFR상 권리부적합에 대한 매수인의 구제권에 관한 연구 (A Study on the Buyer's Remedies for Defects in Title under DCFR)

  • 민주희
    • 무역학회지
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    • 제45권2호
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    • pp.67-86
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    • 2020
  • This study analyzes the buyer's remedies for defects in title under DCFR, and it is compared with those of CISG. DCFR adopts a unitary concept of 'non-performance' which is any failure and includes delayed performance and any other performance which is not conformed with the contract. In terms of defects in title, any remedies for non-performance are available under DCFR. Thus. under DCFR, the buyer is entitled to enforce specific performance of obligations, to withhold performance, to terminate for fundamental non-performance, to reduce price, to damage for loss, to require repair, or to deliver a replacement. But under CISG, whether or not defects in title constitute 'non-conformity' is not clear and the majority understands 'non-conformity' does not include title defects. Therefore, the buyer may not has rights to require repair and delivery of replacement unlike DCFR.

진동제어 콘크리트 보의 하중단계에 따른 동적특성에 관한 실험적 연구 (Experimental Study on Dynamic Characteristics of Damage-Controlled Concrete Beam)

  • 최우성;이대형;전환석;정영수
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1997년도 봄 학술발표회 논문집
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    • pp.500-507
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    • 1997
  • Recently, the construction of infrastructures has been booming and accelerating to keep up with rapid economic growth. Construction activities and operation of transportation facilities cause unfavorable effects such as civil petitions associated with vibration-induced damages or nuisances. The objective of this study is to develop vibration-controlled concrete using various vibration-controlling materials , and also to investigate dynamic properties of concrete beam depending on damage level. Vibration-controlled mixtures are latex, rubber powder and plastic resin, which have been determines to by and large reduce vibration. KS F2437 has been used to figure out 1st natural frequency and dynamic flexural rigidity. Dynamic damping rations have been, computed by adopting the polynomial curvefitting method on the frequency spectrum curve, of which results have been compared and analyzed hereon

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뉴스초점 - 지진해일의 영향과 방재대책 (Effects of Tsunami and Disaster Response System)

  • 강영승
    • 기술사
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    • 제45권1호
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    • pp.45-48
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    • 2012
  • 이번 일본 북동해안에서 발생한 지진해일에 대한 원인과 영향을 살펴보고 방재대책과 방재대응 시스템의 필요성을 고찰해 보았다. 기술적으로 지진발생을 예측할 수는 없으나 발생한 해일이 해안에 도달하는 시간은 예측이 가능하므로 재난에 대비하기 위한 예보경보시스템 구축이 필요한데 이를 위해 지진해일 감시를 위한 관측시스템 구축과 국가간 긴밀한 협조체계가 필요하다. 또한 방재시설, 방조수문, 육갑, 항구방파제, 하천제방 등 방재구조물의 종류와 효과를 살펴보았다. 우리나라의 경우는 무엇보다 지진해일에 의한 재해정보도의 제작, 보급이 필요하며 해안에 거주하는 주민을 대상으로 지속적인 교육, 훈련을 통해 유사시 인명과 재산의 피해를 최소화하는 노력이 시급한 것으로 판단된다.

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형상관리와 국내외 원전 동향 (Configuration Management and Domestic and International nuclear power plant trends)

  • 고민혁;이대성
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2022년도 추계학술대회
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    • pp.351-353
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    • 2022
  • 국내와 국외를 통틀어서 현재까지 원전사고가 수차례 있었고 이로 인한 크고 작은 피해가 있었다. 해외는 이러한 사고를 줄이기 위해서 형상관리라는 기술을 도입하여 원전 운영에 대한 안전성과 신뢰성을 향상 시켜왔다. 본 논문에서는 형상관리에 관한 기본적인 정보와 국외 원전의 형상관리 도입 성공사례들을 통해서 국내에 적용 가능한 기술적 부분을 확인하고 이를 국내 원전에 맞게 보완하여 새로이 적용할 수 있는지를 알아본다.

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A Study on the Wave Formation and Hair Damage Levels Relating to the Uses of Treatments for Heat Permanent Waves

  • Kim, Kwan-Ok;Kim, Sung-Nam
    • 패션비즈니스
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    • 제12권6호
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    • pp.1-10
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    • 2008
  • Public interest in healthy hairs gets growing as damaged hairs are seen more frequently with the generalization of heat permanent waves. For this study, experiments have been conducted to understand the influences on the changes in physical and morphological features of wave forms and damaged hairs, by collecting virgin hairs from the women in their mid-20's, who had not experienced chemical applications, and by dividing the applications of heat perm hair treatments, PPT(for pre-treatment) and LPP(for post-treatment), into the pre-treatment, the post-treatment, the pre & post-treatment, and the non-treatment. For the wave formations, curl waves were investigated by the bare eyes using the pictures taken by a digital camera. For the comparison of physical features, the experiments of tensile strength and elongation were done and their mean values were found. For the observations of morphological features, the pictures were taken by SEM for comparison. As for the findings, regarding the curl wave shapes of hairs, the most even and elastic S curl was formed in the case of non-treatment. In the physical features, both of the tensile strength and elongation showed a decreasing tendency in line with the hair damage levels, and the case of the pre & post-treatment indicated the tendency most similar to the control group. In the morphological features of the cuticle, observed with an SEM, the pre-treatment showed the higher possibility of reducing the cuticle damages than the post-treatment did. LPP was found to play the role of protective membrane for the post-treatment, and the pre & post-treatment turned out to reduce most effectively the cuticle damages.

밸런스 샤프트 모듈 자동 동적검사 시스템 개발 (The Development of an Automatic Dynamic Inspection System of a Balance Shaft Module)

  • 성은제;강대규;정찬용;한창수;김명수
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2007년도 추계학술대회논문집
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    • pp.1231-1236
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    • 2007
  • Balance Shaft Module is module parts that is installed to vehicles engine to reduce noise and vibration of vehicles engine. Balance Shaft Module's performance exerts important influence on performance of engine. Therefore, must be able to warrant quality and performance of Balance Shaft Module. Existing product found and revised error at continuous process of production, and estimated failure mode in Balance Shaft Module. Previous method hard to secure product that performance is excellent, and bring a lot of damages economically. Therefore, development of inspectin system for quality inspection of parts and performance test of assembly is essential in Balance Shaft Module. In this study, represented development process of automatic dynamic inspection system to test performance and detect breakdown of Balance Shaft Module that is producing in Dongbo.

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직류급전계통에서의 레일전위 상승 분석 및 억제 방안 연구 (An Analysis on Rise of Rail Potential And A Study on Control Method for It in DC Feeding System)

  • 민명환;정호성;박영;김형철;신명철
    • 전기학회논문지
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    • 제60권3호
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    • pp.680-685
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    • 2011
  • Nowadays, in metropolitan railroad, DC feeding system is being generally applied. In order to reduce damages of electro-chemical corrosion caused by stray current and leakage current, in DC feeding system, rail is used as negative-polarity return conductor for traction load current. However, it has problem of rail potential increase and there are no adequate measures to prevent it in domestic. In this paper, we presented fundamental theory and related standards about rail potential increase. And then, we analyzed field testing data and simulated a variety of operations by using PSCAD/EMTDC as an analysis program of power system. In addition, voltage control device is suggested to prevent accidents caused by rail potential increase.