• 제목/요약/키워드: combined support system

검색결과 272건 처리시간 0.042초

시스템 동바리 구조 안전성에 대한 최소 수평하중의 영향 (Effects of Minimum Horizontal Load on Structural Safety of System Supports)

  • 정대현;김경윤;원정훈
    • 한국안전학회지
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    • 제30권5호
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    • pp.37-43
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    • 2015
  • This study examined the effects of the minimum horizontal load on the structural behaviors and safety of system supports. The minimum horizontal load was frequently ignored in the design of system supports even though the level of that load was specified in the code and guide in Korea such as 'Standard Specification in Temporary Construction' and 'Guide to Installation of Shores for a Concrete Bridge'. To examine the effects of considering the minimum horizontal load, the finite element analysis were performed for various system supports. By varying installing parameters of system supports such as the vertical member spacing, the installation height, and the thickness of slab, the maximum combined stress ratios were estimated to investigate the structural safety of system supports. The results showed similar axial stress in vertical members but an increase in bending stress with a consideration of the horizontal load. The combines stress ratios are remarkably increased due to the consideration of the horizontal load. Consequently, the system supports, which were initially estimated to be safe when only the vertical loads were considered, were changed to be unsafe in most cases by the effects of the both the vertical and horizontal stresses. Therefore, the minimum horizontal load following the code and the guide is an essential load that could control the structural safety of system supports.

지지면의 수평 진동에 따른 동적 자세 제어 특성에 관한 연구 (Study on the Characteristic of Dynamic Postural Control during Horizontal Translation of Support Surface)

  • 오가영;박용군;권대규;김남균
    • 대한의용생체공학회:의공학회지
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    • 제30권6호
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    • pp.495-502
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    • 2009
  • This paper investigated the effects of dynamic postural control for maintaining upright standing on a support surface during continuous sinusoidal horizontal translation in anterior-posterior direction. 15 healthy young subjects participated in this experiment. The analysis of body movement was analyzed using Ariel Performance Analysis System. Motion pattern was analyzed by seven markers on subject's body. Position of markers were head, chest, hip, right knee, left knee, right ankle and left ankle. Seven different frequencies of support surface were employed ; 0.1, 0.25, 0.5, 0.75, 1, 1.5 and 2Hz at 2cm of moving path of motionbase. The experiments were performed dynamic postural reponses at the condition of eye open. The results showed that median frequency of the knee, ankle were increased in all frequency bands. Following the frequency of perturbation increased, postural control strategy was changed from ankle strategy to combined strategy. The experiment results could be applied to the dynamic postural training for the elderly and the rehabilitation training for the patients to improving the ability of postural control.

EDMS를 이용한 인천국제공항의 대기오염 배출량 산정과 주변지역에 미치는 영향 평가 (Assessment of Air Pollution and Estimation of Emission from Incheon International Airport by EDMS)

  • 이성용;장영기
    • 환경영향평가
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    • 제11권2호
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    • pp.67-77
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    • 2002
  • Air traffic increased 12% annually in Korea since 1988 after the Olympics, this rate is two times than the rate of the world average. In order to accommodate fast growing aviation demand, Incheon International Airport is operated at Yongjong Island since March, 2001. The Incheon airport project will continue till 2020. After the final phase in 2020, Incheon International Airport will handle 100 million passengers, 530,000 flights and 7 million tons of cargo annually. In this study, air pollution from aircraft and other sources are calculated and assessed in Incheon International Airport area by EDMS(Emission and Dispersion Modeling System), which is a combined emission and dispersion model for airport. EDMS could also be considered power plant, incinerator and aircraft support equipment such as ground support equipment, aerospace ground equipment, auxiliary power units. And EDMS is recommended as preferred model for air quality assessment of the airport area by U.S. EP A. The result of this study shows that NOx emission from aircraft and support utility is estimated as 27,000 - 35,000 ton/yr and Namdong-Gu area in Incheon city is affected as 30-60 ppb by the NOx emission from these sources in 2020, the final phase of Incheon international airport construction.

Managing maritime automobile terminals: an approach toward decision-support model for higher productivity

  • Beskovnik, Bojan;Twrdy, Elen
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제3권4호
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    • pp.233-241
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    • 2011
  • The article describes actions and strategies to obtain higher productivity on maritime automobile terminals. The main focus is on elaboration of efficient and effective organizational structure to model and implement short-term, mid-term and long-term strategies. In addition, with an empiric approach we combined the analyses of current findings in important scientific papers and our acknowledgments in practical research of north Adriatic maritime automobile terminals. The main goal is to propose actions towards increasing system's productivity. Based on our research of the north Adriatic maritime automobile terminals and with Lambert's model an in-deep analysis of limiting factors, user's expectations and possibilities for productivity increase has been performed. Moreover, with our acknowledgments a three-level decision-support model is presented. With an adequate model implementation it is possible to efficiently develop and implement different strategies of productivity measurement and productivity increase, especially in the fields of internal transport productivity, entrance/exit truck gates operations and wagon manipulations. According to our observation a significant increase might be achieved in all three fields.

Effect of Heel Raise Exercise with NMES on Peroneus Longus Muscle Strength and Postural Control Ability in Subjects with Functional Ankle Instability: Randomized Controlled Trial

  • Seo, Joon Ho;Lee, Jeon-Hyeong;Lee, Mi Young
    • The Journal of Korean Physical Therapy
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    • 제33권1호
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    • pp.28-33
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    • 2021
  • Purpose: This study examined the effects of heel raise exercises combined with neuromuscular electrical stimulation (NMES) on the muscle strength and postural control ability of subjects with functional ankle instability (FAI). Methods: Twenty-two subjects with FAI participated in this study. They were assigned randomly to two groups: 11 each in the NMES and the sham-NMES groups. Heel raise exercise was applied, and NMES electrodes were attached to the peroneus longus muscles. The NMES group applied NMES during the heel raise exercise. NMES was applied for 20 minutes during the heel raise exercise. The heel raise exercise was performed four times a week for five weeks. The muscle strength and balance error scoring system (BESS) were measured before and after the intervention. Results: A comparison of before and after the intervention within the groups revealed improved muscle strength in the NMES and Sham-NMES groups, but the BESS was improved under all conditions only in the NMES group. The Sham-NMES group showed no improvement in the unstable support surface. Furthermore, when comparing the amount of change before and after the intervention between the groups, there were significant differences in the total score and unstable support in the BESS and muscle strength. Conclusion: NMES had a positive effect on the functional activities of the functional ankle instability subjects, such as balancing on an unstable support surface during postural control and increasing muscle strength.

하이브리드 해상풍력 파일 기초 콘크리트 지지구조(MCF) 개발 (New Development of Hybrid Concrete Support Structure with Driven Piles for Offshore Wind Turbines)

  • 김현기;김범준;김기두
    • 한국강구조학회 논문집
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    • 제25권3호
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    • pp.307-320
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    • 2013
  • 기존 해상풍력발전 지지구조물의 단점을 보완한 신형식의 파일 기초 하이브리드 지지구조물을 본 연구에서 제안하였다. 이 지지구조는 콘크리트 자중을 이용한 중력식 기초의 개념으로부터 수정되어 4개의 파일로 지지되며, 강재 샤프트와 원추형 콘크리트가 결합된 하이브리드 형식이다. 규모가 크고 두꺼운 콘크리트의 3차원 해석을 위해, 정확한 기하형상 모델링과 응력의 절점 보간이 가능한 솔리드-쉘 입체요소를 개발하였다. 해양구조물 전용 유한요소 프로그램인 XSEA에 탑재된 솔리드-쉘 요소와 Stream Function 파랑 이론을 적용하여, 제안한 하이브리드 지지구조물에 대해 서남해안 지역의 환경조건을 적용한 준정적 해석 및 고유진동수 해석을 실시하였다. 해석결과, 수평변위가 허용변위 이내로 나타났고, 고유진동수 해석을 통해 하이브리드 구조형식의 동적거동에 대한 우수성을 입증하였다. 결과적으로, 파일지지 하이브리드 지지구조물은 우리나라 서남해안 지역과 같이 연약지반에 적용 할 수 있는 충분한 안정성을 가진 것으로 평가 되었고, 각 부재에 대한 최적화 연구를 통해 경제성 확보가 가능한 것으로 검토되었다.

양력 및 항력 조합형 해상용 풍력발전기 개발에 관한 연구 (A Study on the Development of Wind Turbine using the lift and drag for the Offshore)

  • 김남훈;이병성;윤양일;오진석
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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    • pp.183.3-183.3
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    • 2010
  • This is the research of wind turbine that is designed to supply power to offshore buoy system. In order to reach maximum efficiency in limited space, vertical axis wind turbine was used. Vertical axis wind turbine system that was applied in this research has the form of lift and drag blade combined to achieve high efficiency at both high and low speed. In addition, support system was designed and developed to suit the offshore condition.

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XML을 활용한 웹기반 콘크리트 옹벽설계 자동화 시스템 개발 (Development of Web-based Retaining wall Design support system using XML)

  • 노병철;김정훈;최상릉;엄준식;양은익;엄주광
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2003년도 가을 학술발표회 논문집
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    • pp.152-155
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    • 2003
  • The design process of concrete retaining walls includes multiple procedures such as structural analysis, member design, the production of calculation sheets, CAD, and itemized statements of Quantities and costs. The objective of this study is to develope an integrated design system that includes all the steps needed for concrete retaining wall design, and as a result, to improve the quality and efficiency of the design process. In this study, the design steps are divided into structural modules and database, and each module and database is systematically combined for the complete design process. The developed design system is based on Web environment. Therefore it can be used in real time and reduces the design work time and space.

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Mobile Agent를 이용한 학사관리 시스템 (A Study on the School Record System using the Mobile Agent)

  • 강민구;조창석
    • 인터넷정보학회논문지
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    • 제2권3호
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    • pp.1-8
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    • 2001
  • 본 논문에서는 기존의 이동사업자가 독점한 무선인터넷 시장에서 이동사업자의 메뉴에서 정보를 획득하는 방식과 달리, 5개 이동사업자 식별에 의한 유·무선 인터넷 통합서버를 이용한 무선학사관리 시스템의 구축방법으로 학생이 자신의 휴대전화에서 학교의 URL을 직접 접속하면 합격자 조회, 수강신청조회, 성적조회, 입시관련 정보 및 공지사항 보기 등이 가능하다.

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Vibration Analysis of Frame Structural Systems by the Receptance Method

  • Han, S.Y.;Kim, K.C.
    • Selected Papers of The Society of Naval Architects of Korea
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    • 제1권1호
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    • pp.52-64
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    • 1993
  • There exist many frame structural systems having some attachments reducible to damped spring-mass systems, concentracted masses and spring supports. For free and forced vibration analyses of such a system an analytical method based on the receptance method is presented. A framed structure having attachments is considered as a combined system composed of various Timoshenko beam and bar elements and the attachments. So, the vibration characteristics of the system are calculated by synthesizing receptances and Support Displacement Transfer Ratio (SDTR) of beam and bar elements In spectral and/or closed forms, and receptances of the attachments. In forced vibration analysis, arbitrary excitation forces at a point on the structure and displacement excitations at boundaries are considered. Numerical investigations are carried out for verification of the presented method, and the results show good accuracy and very high computational efficiency.

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