• 제목/요약/키워드: Closed-Structure

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A Study on Dynamic Character of Landscape (경관의 동태성에 관한 연구)

  • ;Nakamura, Yoshio;Saito, Ushio
    • Journal of the Korean Institute of Landscape Architecture
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    • v.27 no.3
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    • pp.39-49
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    • 1999
  • The objective of this study is to characterize the landscape retaining dynamic character through the distinction between the spatial structure and the landscape. In this study, the landscape was characterized by the image of environment viewed by human being. Firstly, the landscape was disscussed in terms of such three element as the environment viewed by human being, the psychological detachment from the environment and the meaning of image. Secondly, the dynamic character of the landscape was determined by the comparision between the spatial structure of the static elements and the landscape experience through the case study Soshe garden. In the study found that landscape experience depend on the dynamic viewpoint and human views while the spatial structure is stable and static. This study also found that landscape is an open system which can be diachronically transformed by human value, while spatial structure is a synchronic closed system.

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Active Vibration Control of Smart Hull Structure Using MFC Actuators (MFC 작동기를 이용한 스마트 Hull 구조물의 능동 진동 제어)

  • Sohn, Jung-Woo;Kim, Heung-Soo;Choi, Seung-Bok
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.15 no.12 s.105
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    • pp.1408-1415
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    • 2005
  • Active vibration control of smart hull structure using Macro Fiber Composite (MFC) actuator is performed. Finite element modeling is used to obtain governing equations of motion and boundary effects of end-capped smart hull structure. Equivalent interdigitated electrode model is developed to obtain piezoelectric couplings of MFC actuator. Modal analysis is conducted to investigate the dynamic characteristics of the hull structure, and compared to the results of experimental investigation. MFC actuators are attached where the maximum control performance can be obtained. Active controller based on Linear Quadratic Gaussian (LQG) theory is designed to suppress vibration of smart hull structure. It is observed that closed loop damping can be improved with suitable weighting factors in the developed LQG controller and structural vibration is controlled effectively.

A Study on the Shape-Determination for the Unit-structure of Truss Stabilized by the Cable Tension (장력안정화 트러스의 단위구조 형상결정에 관한 연구)

  • 권택진;한상을;최옥훈
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1997.04a
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    • pp.152-159
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    • 1997
  • This unit - structure of truss stabilized by cable tension is composed of four truss member adding to a central post and eight cables, and is connected by hinge joints and is stabilized by cable tension. As this unit - structures itself is a statically closed and stabilize system individually, it can be employed to assemble a structure with a variety of configuration. In this paper, for determination the shape of the unit - structure of truss stabilized by the cable, characteristics such as the stabilized range of the various geometrical parameter about unit system and the relation of the best governing paramter is demonstrated, and the relation of the results is compared in the range for the stabilization of unit-structure.

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Active Vibration Control of Smart Hull Structure Using MFC Actuators (MFC 작동기를 이용한 스마트 Hull 구조물의 능동 진동 제어)

  • Sohn, Jung-Woo;Kim, Heung-Soo;Choi, Seung-Bok
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.11a
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    • pp.217-222
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    • 2005
  • Active vibration control of smart hull structure using Macro Fiber Composite (MFC) actuator is performed. Finite element modeling is used to obtain governing equations of motion and boundary effects of end-capped smart hull structure. Equivalent interdigitated electrode model is developed to obtain piezoelectric couplings of MFC actuator. Modal analysis is conducted to investigate the dynamic characteristics of the hull structure, and compared to the results of experimental investigation. MFC actuators are attached where the maximum control performance can be obtained. Active controller based on Linear Quadratic Gaussian (LQG) theory is designed to suppress vibration of smart hull structure. It is observed that closed loop damping can be improved with suitable weighting factors in the developed LQG controller and structural vibration is controlled effectively.

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Development of Electronic Opening and Shutting Device for One-Ton Wing-Body Truck

  • Han, Jong-Soo;Seo, Chang-Jun
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.565-569
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    • 2004
  • The wing-body trucks are special vehicles that are designed to provide large carrying space and to protect the freights from outside impacts and bad weather. They are constructed to the structure opening and shutting three-layered aluminum top. In the middle- and large-size(above one-ton) wing-body trucks, wing-body is opened/closed by opening and shutting device of oil pressure type. But one-ton truck is constructed that its wing-body is opened/closed in manual to use helping of stay-dampers. So, we developed an electronic opening and shutting device for one-ton wing-body trucks to improve the inconvenience of usage for manually operated wing-body. The developed device is consisted of two connected links and a dc motor combined with an worm gear. The worm gear changes the rotation axis of the dc motor to a right-angled direction and transfers the torque of dc motor to the links. The two connected links open/shut the wing-body using the torque transferred from the dc motor. When the wing-body starts to be opened, the biggest torque is required from the dc motor for opening the wing-body. And as the wing-body is opened more and more, the required torque is smaller for opening the wing-body. Thus, the structure of two connected links are designed to locate at the center of worm gear so that maximum torque of the dc motor is transferred the links at the initial time starting to open wing-body. The controller of the device with open and closed buttons also is designed to protect the device from over-opening and over shutting operations. The developed device is accomplished for many experiments using actual vehicle. Those experiments show that the device has more excellent performance than the oil pressure type.

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Evaluation of the Effect of Sedimentation Basin Structure on Hydrodynamic Behavior Using CFD (II): The Effect of Trough (CFD를 이용한 침전지 구조가 수리거동에 미치는 영향 평가(II): 트라프의 영향 중심으로)

  • Park, No-Suk;Lim, Jae-Lim;Lee, Sun-Ju;Kwon, Soon-Bum;Min, Jin-Hui
    • Journal of Korean Society of Water and Wastewater
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    • v.19 no.6
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    • pp.758-766
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    • 2005
  • This study was conducted to evaluate the effect of the transverse troughs on hydrodynamic behavior within the a certain full-scale sedimentation basin (flow rate/one basin; $10,000m^3/d$) using CFD simulation and ADV technique. In order to verify the CFD simulation, we measured the factual velocity at 36 points in the full-scale sedimentation basin, whose outlet structure is inadequate, with ADV technique. Both the CFD simulation and the ADV measurement results were in good accordance with each other. From the CFD simulation results of the existing basin, it was investigated that extreme upward flow occurs in the near of two transverse troughs. It was suspected that since the transverse troughs converted the open channel flow into the local closed pipe flow, the increased pressure in this local closed pipe flow region made the extreme upward flow. For solving this problems, it was suggested to modify transverse-typed launder into finger-typed launder and to install a longitudinal baffle in the center in this study. The CFD simulation results of all suggested amendments told us that the extreme upward flow, had occurred especially in the beneath of transverse troughs, was much less in the case of finger typed launder basin than that in the existing basin. Also, it was predicted that installing a longitudinal baffle made the fully developed flow which is more effective for sedimentation.

A study on the computer simulation model of the NONHOLONOMIC rotating motion system about the closed system (폐쇄된 계에서 비 흘로노믹 (NONHOLONOMIC) 회전 운동 SYSTEM에 대한 컴퓨터 씨뮬레이션 모델에 관한 연구)

  • Chung, Byung-Tae
    • Journal of the Korea Computer Industry Society
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    • v.10 no.5
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    • pp.221-226
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    • 2009
  • The closed system's internal rigid body particle rotation motion can be distinguished by a main body that becomes the core of the rotation and the particles that are subjected to the rotation. The instance of particles becoming bounded to the main body as a holonomic system, has till now, been well defined and formulated in the study of Kinetics, and the structure of the formulas relate well to reality. However, when the structure is non-holonomic it deviates from these existing equations. The purpose of this research is to categorize the differences between a holonomic system and a non-holonomic system when rotating, through devices. With a special emphasis on the real phenomenon of the non-holonomic system which will be formulated in the form of a model or computer simulation. With these formulas, the center of mass shift in a closed rotating motion system and confined motion of external friction will be adequately expressed, so that it may be applied to computer graphics motions methods.

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A study on selective hybrid-structure film fabricated by 355nm UV-pulsed laser processing (355nm UV 레이저를 이용한 선택적 하이브리드 구조 필름의 제작에 관한 연구)

  • Kim, Myung-Ju;Lee, Sang-Jun;Shin, Bo-Sung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.5
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    • pp.2979-2984
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    • 2015
  • This paper has presented a new foaming technology of selective hybrid-structured polymer film with expanded pores. The porous structure of closed pore was firstly fabricated by applying the 355nm UV-pulsed laser to 0.1mm thick film that was uniformly mixed with PP pellets, copper powder, and CBA (Chemical Blowing Agent). In order to expand pore size of closed-cell shape, LAMO(Laser Aided Micro pore Opening) processing was conducted to heat the copper powder, and then the bigger pore size of closed-cell more than existing pore size was successfully formed because of rapid conduction of heated metal powder. From the experimental results, various process parameters such as laser fluence, intensity, scan rate, spot size and density of powder and CBA were considerably considered to reveal the correlation among the pore characteristics. In the future, a function experiment will be carried out to use the hybrid film of industrial applications.

Model Updating Method Based on Mode Decoupling Controller with Incomplete Modal Data (불완전 모달 정보를 이용한 모드 분리 제어기 기반의 모델 개선법)

  • Ha, Jae-Hoon;Park, Youn-Sik;Park, Young-Jin
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.11a
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    • pp.963-966
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    • 2005
  • Model updating method is known to the area to correct finite element models by the results of the experimental modal analysis. Most common methods in model updating depend on a parametric model of the structure. In this case, the number of parameters is normally smaller than that of modal data obtained from an experiment. In order to overcome this limitation, many researchers are trying to get modal data as many as possible to date. 1 want to name this method multiple modified-system generation method. These Methods consist of direct system modification method and feedback controller method. The direct system modification Is to add a mass or stiffness on the original structure or perturb the boundary conditions. The feedback controller method is to make the closed food system with sensor and actuator so as to get the closed loop modal data. In this paper, we need to focus on the feedback controller method because of its simplicity. Several methods related the feedback controller methods are virtual passive controller (VPC) sensitivity enhancement controller (SEC) and mode decoupling controller (MDC). Among them, we will apply MDC to the model updating problem. MDC has various advantages compared with other controllers, such as VPC and SEC. To begin with, only the target mode can be changed without changing modal property of non-target modes. In addition, it is possible to fix any modes if the number of sensors is equal to that of the system modes. Finally, the required control power to achieve desired change of target mode is always lower than those of other methods such as VPC. However, MDC can make the closed loop system unstable when using incomplete modal data. So we need to take action to avoid undesirable instability from incomplete modal data. In this paper, we address the method to design the unique and robust MDD obtained from incomplete modal data. The associated simulation will be Incorporated to demonstrate the usefulness of this method.

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A Study on the Characteristic of Contemporary Architecture through Karl B tticher's view on Tectonic (칼뵈티허(Karl B tticher)의 텍토닉을 통해 본 현대 건축의 특성에 관한 연구)

  • Lim Jong-Yup;Lee Sung-Jae
    • Korean Institute of Interior Design Journal
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    • v.14 no.1
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    • pp.3-10
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    • 2005
  • The purpose of this study is to find the relationship between hightech architecture and digital one through the discussion on Karl B tticher's view on tectonic in 19th century. The discussion of tectonics which has not been brought up until recently. Since there are no studies regarding contemporary architecture relating to Karl B tticher's view on tectonic, so it is fairly significant to study Karl B tticher's conception, discussion and relationship of contemporary architecture. To study the essence and meaning of Karl B tticher's view on tectonic in 19th century, we will analyze each examples of hightech architecture and digital architecture through Karl B tticher's dual form. B tticher insist that dualistic relationship is united and produced simultaneously. Because they have so closed relationship each other, it's impossible to apply only decoration without structure. Therefore they have mutual assistant relationship. A relationship can be found between hightech architecture's technology and structural symbol that Karl B tticher tried to find in steel which is new material ornament. Digital architecture can be confirmed as images which are made of maximum expose through consistent dynamics of structure. Karl Btticher try to find structural symbolism between new meterail, iron, and decoration. In modern architecture it has the closed relationship with high-tech technology.