• Title/Summary/Keyword: free motion

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Tenolysis after the reconstruction of PIP joint of the finger using second toe PIP joint free flap (제 2족지 근위지관절 유리피판술을 이용한 수지 근위지관절 재건 후 시행한 건박리술)

  • Park, Hyoung Joon;Lee, Dong Chul;Kim, Jin Soo;Ki, Sae Hwi;Roh, Si Young;Yang, Jae Won
    • Archives of Plastic Surgery
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    • v.36 no.4
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    • pp.450-457
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    • 2009
  • Purpose: The second toe PIP joint free flap is a method of reconstruction used for abnormalities of the PIP joint of the finger. We report the results of the additional tenolysis in patients with a difference between passive ROM and active ROM after second toe PIP joint free flap. Methods: From March 2001 to July 2008, tenolysis was performed in patients with a difference in their active and passive ROM after second toe PIP joint free transfer, performed on 14 fingers. We performed a retrospective analysis of the medical records, noting the clinical and radiological findings. In addition, we measured the preoperative and postoperative range of motion of the PIP joint. Results: The average active ROM was $22.5^{\circ}$ at the three months after the joint transfer surgery, and was $38^{\circ}$ after additional tenolysis between five months and twelve months after the joint transfer. Conclusions: Additional tenolysis, after the second toe PIP joint free flap, might be a good option for improved results in patients with difference in active and passive ROM of a transferred PIP joint.

Numerical Simulation of the Flow around Advancing Ships in Regular Waves using a Fixed Rectilinear Grid System (고정된 직교격자계를 이용한 파랑 중 전진하는 선박주위 유동의 수치시뮬레이션)

  • Jeong, Kwang-Leol;Lee, Young-Gill
    • Journal of the Society of Naval Architects of Korea
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    • v.51 no.5
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    • pp.419-428
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    • 2014
  • This paper presents a numerical simulation method for the flow around advancing ships in regular waves by using a rectilinear grid system. Because the grid lines do not consist with body surface in the rectilinear grid system, the body geometries are defined by the interaction points of those grid lines and the body surface. For the satisfaction of body boundary conditions, no-slip and divergence free conditions are imposed on the body surface and body boundary cells, respectively. Meanwhile, free surface is defined with the modified marker density method. The pressure on the free surface is determined to make the pressure gradient terms of the governing equations continuous, and the velocity around the free surface is calculated with the pressure on the free surface. To validate the present numerical method, a vortex induced vibration (VIV) phenomenon and flows around an advancing Wigley III ship model in various regular waves are simulated, and the results are compared with existing and corresponding research data. Also, to check the applicability to practical ship model, flows around KRISO Container Ship (KCS) model advancing in calm water are numerically simulated. On the simulations, the trim and the sinkage are set free to compare the running attitude with some other experimental data. Moreover, flows around the KCS model in regular waves are also simulated.

Free vibration characteristics of three-phases functionally graded sandwich plates using novel nth-order shear deformation theory

  • Pham Van Vinh;Le Quang Huy;Abdelouahed Tounsi
    • Computers and Concrete
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    • v.33 no.1
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    • pp.27-39
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    • 2024
  • In this study, the authors investigate the free vibration behavior of three-phases functionally graded sandwich plates using a novel nth-order shear deformation theory. These plates are composed of a homogeneous core and two face-sheet layers made of different functionally graded materials. This is the novel type of the sandwich structures that can be applied in many fields of mechanical engineering and industrial. The proposed theory only requires four unknown displacement functions, and the transverse displacement does not need to be separated into bending and shear parts, simplifying the theory. One noteworthy feature of the proposed theory is its ability to capture the parabolic distribution of transverse shear strains and stresses throughout the plate's thickness while ensuring zero values on the two free surfaces. By eliminating the need for shear correction factors, the theory further enhances computational efficiency. Equations of motion are established using Hamilton's principle and solved via Navier's solution. The accuracy and efficiency of the proposed theory are verified by comparing results with available solutions. The authors then use the proposed theory to investigate the free vibration characteristics of three-phases functionally graded sandwich plates, considering the effects of parameters such as aspect ratio, side-to-thickness ratio, skin-core-skin thicknesses, and power-law indexes. Through careful analysis of the free vibration behavior of three-phases functionally graded sandwich plates, the work highlighted the significant roles played by individual material ingredients in influencing their frequencies.

Free Vibration Analysis of Composite H-Type Cross-section Beams (복합재료 H형 단면 보의 자유진동 해석)

  • Kim, Sung-Kyun;Song, Oh-Seop
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.20 no.5
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    • pp.492-501
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    • 2010
  • Equations of motion of thin-walled composite H-type cross-section beams incorporating a number of nonclassical effects of transverse shear and primary and secondary warping, and anisotropy of constituent materials are derived. The vibrational characteristics of a composite thin-walled beam exhibiting the circumferentially asymmetric stiffness system(CAS) and the circumferentially uniform stiffness system(CUS) are exploited in connection with the bending-transverse shear coupling and the bending-twist coupling resulting from directional properties of fiber reinforced composite materials.

Force Distribution Algorithms For Singularity-Free 3-DOF Parallel Haptic Device With Redundant Actuation

  • Kim, Tae-Ju;Chung, Goo-Bong;Yi, Byung-Ju;Seo, Il-Hong
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.1598-1602
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    • 2003
  • The parallel-type mechanism provides more accurate and stiff motion than the serial-type mechanism. However, in case of using the haptic device, the performance of the force reflection can be deteriorated due to the singular points existing in workspace. In this paper, we propose a redundantly actuated parallel 3-DOF haptic device, which is singularity-free in the workspace and has an improved force reflection capability. In addition, we propose a new force distribution algorithm, which can reflect force of both high and low resolution, using two sets of actuator with different size. Redundant actuators are attached to the base frame in order to minimize the inertia of the system. Moreover, a wire and gear reduction system is employed to achieve high force reflection along with soft feeling. We confirm the performance of the force reflection capability throughout simulation.

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3D Bridge-Vehicle interaction Analysis of Cable-Supported Bridges Using Mode Superposition Method (모드중첩법을 이용한 케이블지지교량의 3차원 교량-차량 상호작용 해석)

  • Lee Jun-Seok;Im Myoung-Hoon;Kim Moon-Young
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2005.04a
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    • pp.265-272
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    • 2005
  • For bridge-vehicle interaction analysis of cable-supported brides, the superposition method is applied based on the results of 3-dimensional free vibration analysis using General-purpose FEM Software. This study firstly performs the eigenvalue analysis for the free vertical and the torsional vibration of bridges using FEM analysis. Next the equations of motion considering interaction between bridges and vehicles/train are derived from mode superposition method. And then dynamic analysis is performed using the Newmark numericial method. Finally through the numerical examples, the dynamic responses of cable-supported bridges by this study are presented and discussed.

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Seismic Analysis of liquid Storage Structures Using 2-Dimensional Fluid Elements (이차원 유체요소를 이용한 유체 저장구조물의 지진해석)

  • 김영석;윤정방;김재민;김진웅
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1991.10a
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    • pp.49-56
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    • 1991
  • Seismic analysis of liquid storage structures is carried out by utilizing 2-dimensional fluid elements of a general purpose structural analysis computer program(ADINA), The present analysis focuses on the effects of the wall flexibility and the sloshing of the free water surface. Due considerations are given to the facts that the fluid has no shear resistance and the free surface motion is subjected to the gravity effect. To validate the present method using 2-dimensional fluid elements, the results of several example cases are compared with those by the Housner's approach for rigid wall case, and with those by the Eulerian formulation for flexible wall case.

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DEVELOPMENT OF WEB-BASED JAVA PROGRAM FOR NUMERICAL ANALYSIS OF PIPE FLOW (관내 유동 해석을 위한 웹기반 자바 프로그램 개발)

  • Kim, K.S.;Park, J.C.
    • Journal of computational fluids engineering
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    • v.15 no.1
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    • pp.88-94
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    • 2010
  • In general, flow analysis programs have been built in not JAVA language but such as Fortran, C or C++ because of a merit in performance of computation. However, most developer of those languages are not free for use. User should purchase the development tools of programs, and install it on their own computer. Fortunately, JAVA is a free software, and can be used to develop WEB-based programs. It is well known that the JAVA language is time consuming for calculating. However, the performance of computer power has been increased continuously, so it is sure that the former states can be overcome. In the present study, a flow analysis program, which is interactive with Graphics, using the Web-based programing language, JAVA, has been developed for solving the two-dimensional flow motion.

Free Vibration Analysis of Fluid Vessel with Annular and Circular Plates (환형평판과 원판으로 구성된 유체용기의 고유진동 해석)

  • Jeong, Kyeong-Hoon;Kim, Jong-In;Park, Keun-Bae
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.05a
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    • pp.295-300
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    • 2005
  • An analytical method for the hydroelastic vibration of a vessel composed of an upper annular plate and a lower circular plate is developed by the Rayleigh-Ritz method. The two plates are clamped along a rigid cylindrical vessel wall. It is assumed that the fluid bounded by a rigid cylindrical vessel is incompressible and non-viscous. The wet mode shape of the plates is assumed as a combination of the dry mode shapes of the plates. The fluid motion is described by using the fluid displacement potential and determined by using the compatibility conditions along the fluid interface with the plate. Minimizing the Rayleigh quotient based on the energy conservation gives an eigenvalue problem. It is found that the theoretical results can predict well the fluid-coupled natural frequencies comparing with the finite element analysis result.

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Free Vibration Analysis of Fluid Vessel with Annular and Circular Plates (환형평판과 원판으로 구성된 유체용기의 고유진동 해석)

  • Jeong, Kyeong-Hoon;Kim, Jong-In;Park, Jin-Seok
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.15 no.8 s.101
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    • pp.968-974
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    • 2005
  • An analytical method for the hydroelastic vibration of a vessel composed of an upper annular plate and a lower circular plate is developed by the Rayleigh-Ritz method. The two plates are clamped along a rigid cylindrical vessel wall. It is assumed that the fluid bounded by a rigid cylindrical vessel is incompressible and non-viscous. The wet mode shape of the plates is assumed as a combination of the dry mode shapes of the plates. The fluid motion is described by using the fluid displacement potential and determined by using the compatibility conditions along the fluid interface with the plate. Minimizing the Rayleigh quotient based on the energy conservation gives an eigenvalue problem. It is found that the theoretical results can predict well the fluid-coupled natural frequencies comparing with the finite element analysis result.