• 제목/요약/키워드: force support system

검색결과 328건 처리시간 0.031초

프리캐스트 콘크리트 슬래브 보강을 위한 잭킹력과 솟음 (Jacking Force and Camber for Precast Concrete Slab Reinforcing)

  • 노병철
    • 한국구조물진단유지관리공학회 논문집
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    • 제25권2호
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    • pp.43-48
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    • 2021
  • 프리캐스트 콘크리트는 일반적으로 건설 기간을 줄이고 시공 능력을 향상시키는 데 주로 사용되고 있다. 그러나 분할 과정에서 원래 구조 시스템과 다른 경계 조건과 구조적 거동을 적용하여 구조적 문제가 발생할 수도 있다. 이 연구에서는 시공 후 휨모멘트 및 크리프 증가로 인해 처짐과 균열이 발생한 프리캐스트 콘크리트 슬래브를 대상으로 검토하였으며, 이는 프리캐스트 콘크리트 슬래브의 지지 조건 및 구조거동에 대한 잘못된 적용에서 비롯된 것임을 알 수 있었다. 프리캐스트 콘크리트 슬래브 하부에 2 개의 지지대를 삽입하여 휨모멘트를 줄이고 보강 작업시 구조적 안전성을 확보하기 위해 잭킹력에 따른 캠버를 추정해야 한다. 따라서 기존 구조물의 처짐 및 균열을 확인하기 위해 역 해석을 통해 프리캐스트 콘크리트 슬래브의 다양한 지지 조건과 휨강성을 고려하였으며, 프리캐스트 콘크리트 슬래브의 잭킹력에 따라 캠버를 추정하고 안전한 구조물을 만드는 보강방법을 제안하였다.

A Study on Technique of Navigation with Power-Reflected of the Walker in the Indoor Environment

  • Kim, Min-Sik;Kwon, Hyouk-Gil;Ryu, Je-Goon;Shim, Hyeon-Min;Lee, Eung-Hyuk;Shim, Jea-Hong;Lee, Sang-Moo
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2005년도 ICCAS
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    • pp.957-962
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    • 2005
  • Today, the elderly is increasing gradually in the Republic of Korea society and this problem will be more serious in the near future. Therefore, engineering support for aged people is required. We are establishing a new field of healthcare engineering for elderly people and aiming to support for aged people and disabled people using adaptive control and instrument technology. In this paper, the goal is to implement the shared control of a robot mobility aid for the elderly. As using this type of assistive technology to be useful by its intended user community, it supports elderly people and handicapped people to live independently in their private homes. The interface transforms the force applied by the user into the robot's motion. Devices like buttons, joysticks, and levers already exist for relaying user input; however, they require hand displacement that would loosen or otherwise release the user's hold. Such interfaces make operation very difficult and potentially unsafe. Therefore, we propose a shared control system. It's safe more than joysticks and buttons. The shared control is a means of registering the user's intention through physical interaction. It's an important component in the development of robotic elderly assistant. The concept of shared control describes a system which is two or more independent control systems. We are using that the three component blocks consist of pressure sensor (flexible force sensor), circuit of measurement and transfer function. Experimental trials of this paper have been tested at the indoor environment. The robot is able to know the user intended direction through haptic device were logged along with the robot's force sensor.

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Dynamic state estimation for identifying earthquake support motions in instrumented structures

  • Radhika, B.;Manohar, C.S.
    • Earthquakes and Structures
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    • 제5권3호
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    • pp.359-378
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    • 2013
  • The problem of identification of multi-component and (or) spatially varying earthquake support motions based on measured responses in instrumented structures is considered. The governing equations of motion are cast in the state space form and a time domain solution to the input identification problem is developed based on the Kalman and particle filtering methods. The method allows for noise in measured responses, imperfections in mathematical model for the structure, and possible nonlinear behavior of the structure. The unknown support motions are treated as hypothetical additional system states and a prior model for these motions are taken to be given in terms of white noise processes. For linear systems, the solution is developed within the Kalman filtering framework while, for nonlinear systems, the Monte Carlo simulation based particle filtering tools are employed. In the latter case, the question of controlling sampling variance based on the idea of Rao-Blackwellization is also explored. Illustrative examples include identification of multi-component and spatially varying support motions in linear/nonlinear structures.

대형구조물 동특성 실험을 위한 가변 동하중 가진 시스템 개발 (A Development of a Variable Dynamic Force Type Exciter for Modal Test of a Large Structure)

  • 손성완;이홍기;최수현;강동억
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2002년도 추계학술대회논문집
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    • pp.826-831
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    • 2002
  • In order to investigate the dynamic characteristics of real structure, many dynamic engineer had been interested in modal test however it is not easy to perform dynamic test of large structure because of many difficulties such as unsatisfied excitation force in global mode frequency range, measurement of dynamic force and so on. Therefore. new type vibration exciter with variable stiffness support system and dynamic force was developed to provide a improved experimental environment for a large and complex structure. The developed exciter improved from two viewpoint, dynamic performance and utility convenience. its characteristics was shown in this paper.

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Structure's base design for earthquake protection numerical and experimental study

  • Alsaif, K.;Kaplan, H.
    • Structural Engineering and Mechanics
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    • 제16권1호
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    • pp.101-114
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    • 2003
  • A base isolation system is proposed for earthquake protection of structures. The system incorporates spherical supports for the base, a specially designed spring-cam system to keep the base rigidly supported under normal condition and to allow it to move for the duration of the earthquake under the constraint of a spring with optimized non-linear characteristics. A single-story model is constructed to investigate the feasibility of the concept. Numerical simulations of the system as well as experimental results show that 95% reduction of the transmitted force to the structure can be achieved. To demonstrate the effectiveness of this isolation mechanism, the maximum dynamic bending stress developed at predetermined critical points within the frame of the structure is measured. Significant reduction of the dynamic stresses is obtained.

하이브리드 베어링 지지 저손실 에너지 저장 시스템의 축방향 영구자석 베어링 설계기술 연구 (Axial Permanent Magnetic Bearing Design For a Low-Loss Energy Storage Device Mounted on Hybrid Bearing System)

  • 경진호;김유일;최상규;김영철
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 1997년도 춘계학술대회논문집; 경주코오롱호텔; 22-23 May 1997
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    • pp.272-277
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    • 1997
  • The axial bearing using two ring type permanent magnets to support the weight of a flywheel is proposed to reduce the bearing loss in a flywheel energy storage , system. Two permanent magnet makes stable force in axial direction but unstable force in lateral direction. The lateral unstable stiffness is identified quantitatively using flux analysis, and then through the rotor dynamic analysis on a rigid flywheel system the unstable effects on the system by the stiffness is investigated.

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항공탄약 구매 비용 절감 방안에 관한 연구 (A Study on the Cost Reduction Strategy of Aviation Ammunition)

  • 김유현;엄정호
    • 안보군사학연구
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    • 통권15호
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    • pp.57-86
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    • 2018
  • The ROKAF has been training for a number of exercise for victory in the war, but the lack of aviation ammunition has become a big issue every year. However, due to the limitation of defense resources, there are many difficulties in securing and stockpiling ammunition for the war readiness. Therefore, there is a need to find a way to secure aviation ammunition for war readiness in a more economical way, so In this study, we analyze the precedent research case and the case of the reduction of the purchase cost of weapon system of other countries, and then I have suggested a plan that is appropriate for our situation. As a result of examining previous research cases for this study, there were data that KIDA studied in 2012, Precision-guided weapons acquisition cost reduction measures pursued by US Air Force And the use of procurement agencies that are being implemented by NATO member countries. Based on this study, the following four measures were proposed to reduce the purchase cost of aviation ammunition. First, the mutual aid support agreement was developed to sign the ammunition joint operation agreement. Second, join the NATO Support & Procurement Agency (NSPA) Third, it builds a purchasing community centered on the countries operating the same ammunition Fourth, participating in the US Air Force's new purchase plan for ammunition and purchase it jointly. The main contents of these four measures are as follows. 1. the mutual aid support agreement was developed to sign the ammunition joint operation agreement. Korea has signed agreements on mutual logistics support with 14 countries including the United States, Israel, Indonesia, Singapore, Australia, and Taiwan. The main purpose of these agreements is mutual support of munitions and materials, also supporting the training of the peace time and promoting exchange and cooperation. However, it is expected that there will be many difficulties in requesting or supporting mutual support in actual situation because the target or scope of mutual aid of ammunition is not clearly specified. Thus, a separate agreement on the mutual co-operation of more specific and expanded concepts of aviation ammunition is needed based on the current mutual aid support agreements 2. join the NATO Support & Procurement Agency (NSPA) In the case of NATO, there is a system in which member countries purchase munitions at a low cost using munitions purchase agencies. It is the NATO Purchasing Agency (NSPA) whose mission is to receive the purchasing requirements of the Member Nations and to purchase them quickly and efficiently and effectively to the Member Nations. NSPA's business includes the Ammunition Support Partnership (ASP), which provides ammunition purchase and disarming services. Although Korea is not a member of NATO, NSPA is gradually expanding the scope of joint procurement of munitions, and it is expected that Korea will be able to join as a member. 3. it builds a purchasing community centered on the countries operating the same ammunition By benchmarking the NSPA system, this study suggested ways to build a purchasing community with countries such as Southeast Asia, Australia, and the Middle East. First, it is necessary to review prospectively how to purchase ammunition by constructing ammunition purchasing community centered on countries using same kind of ammunition. 4. participating in the US Air Force's new purchase plan for ammunition When developing or purchasing weapons systems, joint participation by several countries can reduce acquisition costs. Therefore, if the US Air Force is planning to acquire aviation ammunition by applying it to the purchase of aviation ammunition, we will be able to significantly reduce the purchase cost by participating in this plan. Finally, there are some limitations to the method presented in this study, but starting from this study, I hope that the research on these methods will be actively pursued in the future.

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통합환경허가시스템의 활용도 제고 및 개선방향 (Enhancing the Applicability and Improvement Direction of Integrated Environmental Permit System)

  • 박재홍;신수정;이대균
    • 한국물환경학회지
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    • 제34권3호
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    • pp.339-345
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    • 2018
  • The integrated environmental permit system is currently in operation online. It carries out various functions of postmanagement such as the submission of annual reports containing operations management data onto integrated management workplaces, the operation and management of emission facilities and prevention facilities, and the disclosure of information on the integrated permission. On the other hand, the integrated environmental permit system needs to perform various roles in order to stably manage and smoothly perform the permitting work. It is necessary to utilize this system to establish policies by using diverse operations management data onto integrated management workplaces collected in the integrated environmental permit system. This system can also play a role in improving the post-management system and user convenience after the permission review and approval processes. The integrated environmental permit system can be effectively used to set up the BAT-AEL because it collects all of the cross-media data and identifies the overall status of the workplace. In order to establish a post management system after the approval, it is necessary to provide performance management and performance evaluation functions as conditions of the permit after approval. In addition, a variety of support functions should be provided to enable the permission authority and the environmental expert examination agency to facilitate the review of permits. It will be necessary to provide an evaluation system and a proactive diagnostic function to determine whether permission conditions and permit emission standards will change in the future. Also, it is important to adopt an information exchange platform that can be used to collect the status data onto the workplaces; the platform can also be used as an information exchange site for technical working groups (TWG), and for collecting field experts' opinions.

충격파 터널에서의 가속도계 기반 항력 측정 (Accelerometer-based Drag Measurement in a Shock Tunnel)

  • 장병국;김근영;박기수
    • 한국항공우주학회지
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    • 제48권7호
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    • pp.489-495
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    • 2020
  • 충격파 터널에서 항력 측정을 위하여 가속도계 기반 시스템을 설계 및 구축하고, 마하 6 유동조건에서 원뿔형 모델의 항력계수를 측정하였다. 항력 측정 시스템의 마찰력을 보정하기 위하여 간단하고 직관적인 교정 방식을 제시하고, 항력 측정 결과를 단순 원뿔형 모델의 전산유체역학 해석 결과와 비교, 분석하였다. 다양한 형상의 지지대를 이용하여 지지대에 의한 항력 측정 간섭 영향을 파악하고 이를 최소화하기 위한 디자인을 제시하였다. 수정된 지지대를 이용하여 항력계수를 측정한 결과, 지지대에 의한 항력계수 오차가 작아지는 것이 확인되었다.

휨 저항을 고려한 네일 거동에 대한 수치해석적 분석 (Numerical Analysis of the Nail Behavior Considering Resisting Bending Moment)

  • 전상수;김두섭;장양원
    • 한국지반공학회논문집
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    • 제23권10호
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    • pp.85-96
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    • 2007
  • 쏘일 네일 공법은 기존의 지보공법에 비해 시공의 편리성과 경제성, 안정성이 우수하여 최근 현장에 적용되는 사례가 증가하고 있다. 하지만, 쏘일 네일 공법에 대한 공학적인 접근은 미흡하여 우리나라에서는 지금까지 체계적인 설계 공법이 확립되지 못한 실정이다. 기존의 쏘일 네일 공법 설계에는 네일에 작용하는 전단 저항 및 휨 저항을 고려하지 않았으나, 철근과 시멘트로 구성된 쏘일 네일은 전단 및 휨에 대한 저항을 가지고 있다. 따라서, 본 논문에서는 네일의 전단 및 휨 저항을 고려한 쏘일 네일 보강시 수치해석 프로그램인 $FLAC^{2D}$를 이용해 사면의 안정성을 분석하였다.