• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2000년도 추계학술대회 논문집
• /
• pp.670-673
• /
• 2000

This paper attempt analysis and computer simulation of dynamics of a set of dual multi-joint fingers with soft-deformable tips which are grasping. Firstly, a set of differential equation describing dynamics of the fingers and object together with geometric constraint of tight area-contacts is formulated by Euler-Lagrange's formalism. Secondly, problems of controlling both the internal force and the rotation angle of the grasped object under the constraints of area-contacts of tight area-contacts are discussed. The effect of geometric constraints of area-contacts on motion of the overall system is analyzed and a method of computer simulation for overall system of differential-algebraic equations is presented. Finally, simulation results are shown and the effects of geometric constraints of area-contact is discussed.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2001년도 ICCAS
• /
• pp.132.6-132
• /
• 2001

This paper aims to derive a mathematical model of the dynamics of handling tasks in field robot which stable grasping and manipulates a rigid object with some dexterity. Firstly, a set of differential equation describing dynamics of the manipulators and object together with geometric constraint of tight area-contacts is formulated by Lagrange equation. Secondly, problems of controlling both the internal force and the rotation angle of the grasped object under the constraints of area-contacts of tight area-contacts are discussed. The effect of geometric constraints of area-contacts on motion of the overall system is analyzed and a method of computer simulation for overall system of differential-algebraic equations is presented. Thirdly, simulation results are shown and the effects of geometric constraints of area-contact is discussed.

• 대한가정학회지
• /
• 제32권5호
• /
• pp.183-200
• /
• 1994

The purpose of this study is to present the enlargement of the area of the expression. Thish process takes steps as follows : 1)To inquiry the expressed examples in modern fashion through plasticizing the geometric cubic. 2) Through this process to sruvey the potential of the development inherent in fashion design possibility. 3) At the same time to establish the status of fashion as a part of the Plastic Art. This study is to re-illuminate the plasticity expressed in modern fashion. The result of this study testified that in the relation between fashion and the human body the plastic characteristics of geometric cubic enlarged the special three-dimension effect and in the connection of form and from there is a potential possibility of the way of organization in discovering and establishing the world of the new form through the temperate organization.

• 대한기계학회논문집
• /
• 제18권6호
• /
• pp.1365-1373
• /
• 1994

Elasto-dynamic deformation of flexible linkage mechanism was analyzed using the finite element method. A computer program was constructed and applied to analyze a specific crank-level 4-bar mechanism, in which the elasto-dynamic deformation of the mechanism system was obtained using mode superposition method in the case of constant input speed and the effect of geometric stiffness on the mechanism is included. Experimental verification of numerical results was conducted by measuring the elasto-dynamic deformation of mid-points of coupler and lever for the 4-bar lingkage mechanism using high speed camera and image data processing systeem. For the elasto-dynamic deformation at the lever mid-point, the numerical results including geometric stiffness almost agree with the experimental ones. However, the numerical results excluding geometric stiffness good agree with the experimental ones at the couper mid-point.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2006년도 정기 학술대회 논문집
• /
• pp.623-630
• /
• 2006

In this paper, a geometric nonlinear analysis procedure of beam-column element including multi-noded cable element is presented. For this, first a stiffness matrix about beam-column element which considers the second effect of initial force supposing the curved shape at each time step with Hermitian polynomials as the shape function is derived and second, tangent stiffness matrix about multi-noded cable element being too. To verify geometric nonlinearity of this newly developed multi-noded cable-truss element, IPS(Innovative Prestressed Support) system using this theory is analysed by geometric nonlinear method and the results are compared with those by linear analysis.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1996년도 추계학술대회 논문집
• /
• pp.95-99
• /
• 1996

The form accuracy of parts has become an important parameter. Therefore dimensional tolerance and geometric tolerance are used in design to satisfy required quility and functions of parts. But the informations for machining conditions, which can satisfy the assigned geometric tolerance in design, are insufficient. The objectives of this research are to study the effects of the grinding parameters such as traverse speed, work speed, depth of cut, and dwell time on the after-ground workpiece shape, and to find out the major parameters among these parameters. Finally, a methodology is proposed for getting the optimal grinding condition for precision workpiece The results are as follows; The effects of work speed and depth of cut on workpiece shape are ignorable compared to the effect of traverse speed. These is the optimal dwell time depending on the traverse speed. The optimal dwell time is decreasing when the traverse speed is increased.

• 대한기계학회논문집
• /
• 제17권11호
• /
• pp.2655-2663
• /
• 1993

In order to evaluate the relative significance of tolerance management of various elements in a VHS VTR tape transport system, the effect of geometric variations of the elements from standard design values on the tape traveling path is studied. The tape is modeled as a string and each element in the tape transport system is modeled as a cylinder whose radius, position vector and orientation vector are specified. An numerical algorithm is proposed to find the coordinates of tape entry points and tape exit points for the elements from which the tape traveling path can be completely described. By using the suggested algorithm, an error sensitivity analysis of tape traveling path due to the geometric variations of tape transport elements is performed for a particular model in the market and the elements demanding relatively strict tolerance management are identified.

• Advances in nano research
• /
• 제13권4호
• /
• pp.379-391
• /
• 2022

One factor that can heighten the risk of the rapture intracranial aneurysm (IA) is bifurcations, which can cause the IA to evaluate. This study presents the effect of geometric of intracranial vascular on the bifurcation analysis of the aneurysm occurrence. The aneurysm mechanism is mathematically modeled based on the nano pipe structures under the thermal stresses, and the impact of the aneurysm geometric on the stability and bifurcation points is analyzed. Because of the dimension of these structures, the classical theories could not predict their behavior perfectly, so the nonclassical and nonlocal theories are required for the mechanical modeling of the aneurysm. The presented results show that the bifurcation point of the aneurysm mechanism is dependent on the environment temperature, and the temperature change plays an essential role in the stability of these structures.

• Structural Engineering and Mechanics
• /
• 제88권4호
• /
• pp.355-368
• /
• 2023

Employing the non-local strain gradient theory (NSGT), this paper investigates the nonlinear resonance characteristics of functionally graded material (FGM) nanoshells with initial geometric imperfection for the first time. The effective material properties of the porous FGM nanoshells with even distribution of porosities are estimated by a modified power-law model. With the guidance of Love's thin shell theory and considering initial geometric imperfection, the strain equations of the shells are obtained. In order to characterize the small-scale effect of the nanoshells, the nonlocal parameter and strain gradient parameter are introduced. Subsequently, the Euler-Lagrange principle was used to derive the motion equations. Considering three boundary conditions, the Galerkin principle combined with the modified Lindstedt Poincare (MLP) method are employed to discretize and solve the motion equations. Finally, the effects of initial geometric imperfection, functional gradient index, strain gradient parameters, non-local parameters and porosity volume fraction on the nonlinear resonance of the porous FGM nanoshells are examined.

• 복식
• /
• 제39권
• /
• pp.99-111
• /
• 1998

Cubism has played a great role to change traditional concept of art and visual of people as developed into one of new art stlyes. It has avoided three dimensional perspectives and reformed the concept of time and space. It expresses objects with geometric shape by simplifying and reconstructing the objects after taking them apart. This has the effect of simultaneous vision and transparency and brings in collage by combining geometric image and visual elements. The results of the study as follows: First, the geometric shape expresses straight lines, curves, faces, and cubics by simplifying the objects. In fashion, it expresses circles, triangles, squares with a cloth. This shows visual changes as three dimensional space moves. Second, simultaneity disassembles and recontructs the objects. It tries to understand the internal shape with method of disassembling and makes visions coexist. In so doing, cubists adopt simultaneity for expressing shapes. In fashion, it expresses new items through disassembling or combining with other items. Third, transparency simplifies cubics by duplicating with transparent flats and crosses contour lines for reconstructing the simplified objects. This implies broader spatial order. It allows people to perceive penetration of layed clothes. Fourth, collage expresses geometric shape by adding visual elements(concrete image and color). It uses concrete image with paper, letters, cloth, etcs, which is not related to painting, and introduces various colors. In fashion, it uses dolls, postcards, feathers, metals, plastics, for patchwork.