• Title/Summary/Keyword: free motion

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Moving boundary condition for simulation of inundation (범람 모의를 위한 이동경계조건)

  • Lin, Tae-hoon;Lee, Bong-Hee;Cho, Dae-Hee;Cho, Yong-Sik
    • Journal of Korea Water Resources Association
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    • v.36 no.6
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    • pp.937-947
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    • 2003
  • A shoreline, which has no the water depth, moves continuously as waves rise up and recede. Therefore, a special boundary treatment is required to track properly the movements of the shoreline in numerical modeling of the behavior of tsunamis or tides near a coastal zone. In this study, convective terms in nonlinear shallow-water equations are discretized explicitly by using a second-order upwind scheme to describe a moving shoreline more accurately. An oscillatory flow motion in a circular paraboloidal basin has been employed to validate the performance of the developed numerical model. Computed results of instantaneous free surface displacements are compared with those of analytical solutions and existing numerical solutions. The run-up heights in the vicinity of a circular island have also been calculated and obtained numerical results have been shown against available laboratory measurements. A good agreement has been observed.

Interference-free French door design using four-bar linkage mechanism (4절 링크를 이용한 프렌치 도어의 간섭 방지 설계)

  • Lee, Jin-Gyu;Yun, Jae-Deuk;Jung, Yoong-Ho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.5
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    • pp.2031-2037
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    • 2011
  • The French doors have the advantage that they can use inner space more efficiently due to without of partition between two rooms. However, when they are used for refrigerators, the door gaskets for sealing may cause interference of themselves during opening and closing, which causes fatal effect on sealing by worn out of the gaskets as well as increases door opening force. This research proposes a new mechanism for the French doors using the parallelogram motion of 4-bar linkage mechanism, which does not make any interference between gaskets. We manufactured the French doors of proposed mechanism to verify that they do not cause any interference during opening and closing, as well as opening force is decreased. The use of our developed mechanism is not limited to refrigerators, but can be extended to other industrial products with the French doors.

Development of Automatic Hole Position Measurement System using the CCD-camera (CCD-카메라를 이용한 홀 변위 자동측정시스템 개발)

  • 김병규;최재영;강희준;노영식
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.10a
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    • pp.127-130
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    • 2004
  • For the quality control of the industrial products, an automatic hole measuring system has been developed. The measurement device allows X-Y movement due to contact forces between a hole and its own circular cone and the device is attached to an industrial robot. Its measurement accuracy is about 0.04mm. This movement of the plate is measured by two LVDT sensor system. But this system using the LVDT sensors is restricted by high cost and precision of measurement and correspondence of environment so particularly, a vision system with CCD-Camera is discussed in this paper for the above mentioned purpose. The device consists of two of two links jointed with hinge pins basically and, they guarantee free movement of the touch prove attached on the second link in the same plane. These links are returned to home position by the spring plungers automatically after each process for the next one. On the surface of the touch prove, it has a circular white mark for camera recognition. The system detect and notify the center coordinate of capture mark image through the image processing. Its measuring accuracy has been proved to be about $\pm$0.01mm through the repeated implementation over 200 times. This technique will shows the advantage of touch-indirect image capture idea using cone-shaped touch prove in various symmetrical shaped holes particulary, like tapped holes, chamfered holes, etc As a result, we attained our object in a view of the accuracy, economical efficiency, and functionality

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Study on the Radiation Forces on a Pontoon Type Floating Structure and Submerged Plate : Hydrodynamic Interaction Effect by Submerged Plate (폰툰형 부체구조물과 몰수평판에 작용하는 라디에이션 유체력에 관한 연구 : 몰수평판에 의한 유체력 간섭 영향)

  • Lee, Sang-Min
    • Journal of Navigation and Port Research
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    • v.31 no.8
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    • pp.683-687
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    • 2007
  • Hydroelastic deformation of pontoon type floating structure in waves is critical in structural design. Therefore, it is necessary to develop additional technology that make to dissipate the wave energy as the submerged horizontal plate. In this study, we investigate the characteristics of hydrodynamic interaction effect by the submerged plate affecting to the radiation forces on a pontoon type floating structure using numerical analysis. We have developed the numerical method based on the composite grid system that consists of moving and fixed grid to compute the radiation forces due to the heaving motion of pontoon type floating structure and submerged plate. The numerical simulations based on the finite difference method are carried out to solve the fully nonlinear free surface involving the breaking waves and compared with the experimental data to confirm the reliability of the numerical method. Then, we discuss the interaction effects on the hydrodynamic forces that could influence on the hydroelastic response of floating structure.

Intraligamentous Ganglionic Cyst of the Posterior Cruciate Ligament: A Case Report (후방십자인대 내에 발생한 관절내 결절종 - 1례 보고 -)

  • Jeong, Jae-Heon;Baek, Ji-Hoon;Lee, Sang-Hak;Jung, Ho-Joong;Ha, Yong-Chan
    • Journal of Korean Orthopaedic Sports Medicine
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    • v.9 no.1
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    • pp.69-71
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    • 2010
  • Ganglionic cyst formation within the posterior cruciate ligament (PCL) of knee has not been reported. We describe a case of an intraligamentous ganglionic cyst of PCL. Arthroscopic technique through both the posteromedial and posterolateral portals was used for approach. Using probe, PCL was splitted and perforated ganglionic cyst at tibial attachement side. At 2 years follow up, the patient was free of symptoms with a full range of motion and follow-up MR image showed that there was no recurred ganglionic cyst.

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Music Visualization Expression in Modern Fashion - Focus on the application of Mondrian's paintings to Alexander McQueen's 2014 Spring Ready-to-wear Collection -

  • Kim, Sung-Soo;Kim, Young-Sam
    • Fashion & Textile Research Journal
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    • v.16 no.1
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    • pp.55-65
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    • 2014
  • This study analyzes music visualization characteristics in modern fashion based on Wassily Kandinsky's music visualization theory. Alexander McQueen's 2014 Spring Ready-to-wear Collection (as inspired by Mondrian's paintings) was selected as the research subject. First, an analysis of Mondrian's paintings based on Wassily Kandinsky's theory shows that music visualization characteristics can be categorized into spatiality, mobility, and duality. Second, McQueen applied Mondrian's paintings to the overall design, structured the model's shape in the painting, or created patterns using colors and lines that introduced them in clothes; symbolic forms were also introduced as part of or a decorative factor of the clothes. Third, spatiality refers to the creation of a feeling of space through emptiness or fill using lines, colors, and shape. Musical atmosphere such as dissonance were expressed in clothing through the application of color contrast, lines and silhouette dynamics, and symbolic format and patterns by Mondrian. Fourth, mobility generally refers to motion caused by a certain stimulus. Mondrian expressed vibration, internal resonance, sound level in music that emphasized color irregularity, primary color contrast, and rough brush touches as well as free and organic patterns. McQueen expressed this with primary color contrast using different materials, rough touch based on texture, and pattern repetition through transformation. Fifth, duality generally refers to the artistic effect caused by overlap. Mondrian created a resemblance of dissonance and music through line and color as expressed through the duality of clothing design components based on the artistic sense of the designer.

An analysis on the Deconstructed Visage in Fashion Illustration - Based on the Deconstructed Visage of Francis Bacon's Painting - (패션 일러스트레이션에 나타난 얼굴해체 - 프란시스 베이컨 회화의 얼굴해체를 바탕으로 -)

  • Choi, Jung-Hwa;Choi, Yoo-Jin
    • Fashion & Textile Research Journal
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    • v.15 no.6
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    • pp.874-885
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    • 2013
  • This study analyzes the visage in fashion illustration based on the deconstructed visage of Francis Bacon's paintings as well as analyzes fashion illustration works since 2000. The deconstructed visages in Francis Bacon's paintings are classified as blurring, elimination, distortion and division. The expressive methods and meanings in fashion illustration (according to categorization) are as follow. Blurring shows an ambiguous visage organ by the sweeping of the brush, removal of a boundary among the visage, body and clothes, gradation of organic line like visage shapes, stretching of the a plat combined to visage and fragmentation of visage. It represents an uncertainty of the fashion theme and image interpretation, impossibility of figure by ambiguity, fantastic effect and the induction of the uncanny. Elimination shows the background color's painting of a photo-montage, overlap of a cutting of visage's part and background of a plat, elimination of the visage and the elimination of eyes, nose or lips. It represents a weakened identity, the reinforcement of anonymity, creation of a violent image, and uncanny unfamiliarity. Distortion shows a distorted visage by free drawing, and unconscious drawing line, fluid digital body, combination of an unconscious curve, and an eccentric combination of the accidental. It represents the relief of specialty about realistic existence, hypothetical immateriality and fantasy. Division shows overlapped visages with different angles, the weird combination of a plural visage and different species and a plural breakaway of direction, and the position of several organs. It represents motion by power's trace, non-territory of species, ambiguity and uncertainty and the uncanny.

Investigation on hygro-thermal vibration of P-FG and symmetric S-FG nanobeam using integral Timoshenko beam theory

  • Matouk, Hakima;Bousahla, Abdelmoumen Anis;Heireche, Houari;Bourada, Fouad;Bedia, E.A. Adda;Tounsi, Abdelouahed;Mahmoud, S.R.;Tounsi, Abdeldjebbar;Benrahou, K.H.
    • Advances in nano research
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    • v.8 no.4
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    • pp.293-305
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    • 2020
  • In the current research, the free vibrational behavior of the FG nano-beams integrated in the hygro-thermal environment and reposed on the elastic foundation is investigated using a novel integral Timoshenko beam theory (ITBT). The current model has only three variables unknown and requires the introduction of the shear correction factor because her uniformed variation of the shear stress through the thickness. The effective properties of the nano-beam vary according to power-law and symmetric sigmoid distributions. Three models of the hygro-thermal loading are employed. The effect of the small scale effect is considered by using the nonlocal theory of Eringen. The equations of motion of the present model are determined and resolved via Hamilton principle and Navier method, respectively. Several numerical results are presented thereafter to illustrate the accuracy and efficiency of the actual integral Timoshenko beam theory. The effects of the various parameters influencing the vibrational responses of the P-FG and SS-FG nano-beam are also examined and discussed in detail.

Development of Potential Function Based Path Planning Algorithm for Mobile Robot

  • Lee, Sang-Il;Kim, Myun-Hee;Oh, Kwang-Seuk;Lee, Sang-Ryong
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.2325-2330
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    • 2005
  • A potential field method for solving the problem of path planning based on global and local information for a mobile robot moving among a set of stationary obstacles is described. The concept of various method used path planning is used design a planning strategy. A real human living area is constructed by many moving and imminence obstacles. Home service mobile robot must avoid many obstacles instantly. A path that safe and attraction towards the goal is chosen. The potential function depends on distance from the goal and heuristic function relies on surrounding environments. Three additional combined methods are proposed to apply to human living area, calibration robots position by measured surrounding environment and adapted home service robots. In this work, we proposed the application of various path planning theory to real area, human living. First, we consider potential field method. Potential field method is attractive method, but that method has great problem called local minimum. So we proposed intermediate point in real area. Intermediate point was set in doorframe and between walls there is connect other room or other area. Intermediate point is very efficiency in computing path. That point is able to smaller area, area divided by intermediate point line. The important idea is intermediate point is permanent point until destruction house or apartment house. Second step is move robot with sensing on front of mobile robot. With sensing, mobile robot recognize obstacle and judge moving obstacle. If mobile robot is reach the intermediate point, robot sensing the surround of point. Mobile robot has data about intermediate point, so mobile robot is able to calibration robots position and direction. Third, we gave uncertainty to robot and obstacles. Because, mobile robot was motion and sensing ability is not enough to control. Robot and obstacle have uncertainty. So, mobile robot planed safe path planning to collision free. Finally, escape local minimum, that has possibility occur robot do not work. Local minimum problem solved by virtual obstacle method. Next is some supposition in real living area.

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Designing FMH Impact-Absorbing Structure by Using Subcomponent Collapse Simulation (단품 압궤 시뮬레이션을 이용한 FMH 충격흡수부재의 설계방법에 관한 연구)

  • Kim, Ji-Hun;Jun, In-Ki;Choi, Jae-Min;Kim, Sung-Hun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.34 no.8
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    • pp.1113-1118
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    • 2010
  • It is requested that the interior compartment of a passenger vehicle must be satisfied with the FMVSS201U regulation, FMH impact test. It is needed the design methodology to find the appropriate structure about the FMH impact. When designing the impact-absorbing structure for the FMH impact test, it is to be noted that the impact absorber must have different performance considering the stiffness of the vehicle as the impact position and approach angle of FMH. In this study, an efficient design methodology was developed by using subcomponent collapse simulation instead of conducting full-vehicle simulation, thereby reducing the time and resources spent. Further, this unit-model simulation helps optimize the impact absorbing structure.