• Proceedings of the KSME Conference
• /
• 2003.11a
• /
• pp.1322-1327
• /
• 2003

It is important to determine supporting locations for structural stability of a structure under non-uniform load in space interfered by other parts. In this case, There are many local optima with discontinuous design space. Therefore, The traditional optimization methods based on derivative are not suitable. Whereas, Genetic algorithm(GA) based on stochastic search technique is a very robust and general method. This paper has been presented to determine supporting locations of the vertical supports for reducing stress of the KSTAR(Korea super Superconducting Tokamak Advanced Research) IVCC(In-vessel control coil) under non-uniform electromagnetic load and space interfered by other parts using genetic algorithm. For this study, we develop a program combining finite element analysis with a genetic algorithm to perform structural analysis of IVCC. In addition, this paper presents a technique to perform optimization with FEM when design variables are trapped in an incongruent design space.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.21 no.2
• /
• pp.199-208
• /
• 2008

In this paper, to analyze the initial valued non-homogeneous elastic half space by the scaled boundary analysis, the infinite element approach was introduced. The free surface of the initial valued non-homogeneous elastic half space was modeled as a circumferential direction of boundary scaled boundary coordinate. The infinite element was used to represent the infinite length of the free surface. The initial value of material property(elastic modulus) was considered by the combination of the position of the scaling center and the power function of the radial direction. By use of the mapping type infinite element, the consistent elements formulation could be available. The performance and the feasibility of proposed approach are examined by two numerical examples.

• Journal of Science Education
• /
• v.47 no.3
• /
• pp.263-272
• /
• 2023

We consider how a pre-service teacher can understand and utilize various concepts of Euclidean geometry by learning conic sections using mathematical definitions in non-Euclidean geometry. In a third-grade class of D University, we used mathematical definitions to demonstrate that learning conic sections in non-Euclidean space, such as taxicab geometry and Minkowski distance space, can aid pre-service teachers by enhancing their ability to acquire and accept new geometric concepts. As a result, learning conic sections using mathematical definitions in taxicab geometry and Minkowski distance space is expected to contribute to enhancing the education of pre-service teachers for Euclidean geometry expertise by fostering creative and flexible thinking.

• Journal of Korean Society of Steel Construction
• /
• v.11 no.2 s.39
• /
• pp.153-165
• /
• 1999

In order to trace the lateral-torsional post-bucking behaviors of thin-walled space frames with non-symmetric cross sections, a geometrically non-linear finite element formulation is presented by applying incremental equilibrium equations based on the updated Lagrangian formulation and introducing Vlasov's assumption. The improved displacement field for non-symmetric thin-walled cross sections is introduced based on inclusion of second order terms of finite rotations, and the potential energy corresponding to the semitangential rotations and moments is consistently derived. For finite element analysis, tangent stiffness matrices of thin-walled space frame element are derived by using the Hermition polynomials as shape functions. A co-rotational formulation in order to evaluate the unbalanced loads is presented by separating the rigid body rotations and pure deformations from incremental displacements and evaluating the updated direction cosines and incremental member forces.

• Journal of the Korea Fashion and Costume Design Association
• /
• v.25 no.1
• /
• pp.153-168
• /
• 2023

Non-representation creates difference and change that can be used as a creative design method that satisfies contradictory requirements for similarity and differentiation. This study drew upon the characteristics of the concept of non-representation expressed in contemporary art and architecture, in which Gilles Deleuze's philosophical thinking was reflected, and analyzed the non-representation depicted in contemporary fashion. The non-representation expressed in contemporary art and architecture is as follows. Non-representation of delaying becoming focuses on reverting to preexisting objects and redefining traditional meaning, thereby delaying the representation of latent meaning. Non-representation of non-becoming removes existing values and typical forms and expresses amorphousness. Non-representation of becoming by repetition or reiteration realizes the difference caused by the passage of time by repeating or overlapping shapes. Non-representation of becoming expresses the transformation of space by flowing through time rather than by actual movement. Non-representation in contemporary fashion shows the following expression characteristics. First, the non-representation of deferring becoming deconstructs the traditional values and forms of clothing and expresses designs by displacement or juxtaposition. Second, the non-representation of non-becoming is expressed concepts unrelated to the body and focus upon amorphous objects that do not become concretized forms. Third, generative non-representation by repetition and overlap expresses the possibility of change by overlapping clothing items or details expressed by repeating segmented objects. Fourth, generative non-representation by movement reproduces the meaning of space and time by moving the shape of the clothing or visually changing the surface of the material of clothing. As a result of the study, the non-representation shown in contemporary fashion aims for versatility to conform to social changes. This study provides new insight into the fashion design method by increasing the understanding of the cocnept of non-representation and showing its potential.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.39 no.8
• /
• pp.719-724
• /
• 2011

A Non_Pneumatic tire (NPT) has spoke to replace air of the pneumatic tires. A NPT appears to have advantages over the conventional pneumatic tire in terms of flat proof and maintenance free. And a NPT can also be used in the space environment since it uses no air for inflation. In this study, the static contact pressure of NPTs with auxetic honeycomb spokes is investigated as a function of vertical loading and is compared with that of a pneumatic tire. The finite element based numerical simulation of the local stress of an airless tire is carried out with ABAQUS for varying vertical force and honeycomb spokes geometries.

• Structural Engineering and Mechanics
• /
• v.27 no.5
• /
• pp.575-588
• /
• 2007

In this paper, two algorithms are presented for the optimum design of geometrically nonlinear steel space frames using tabu search. The first algorithm utilizes the features of short-term memory (tabu list) facility and aspiration criteria and the other has long-term memory (back-tracking) facility in addition to the aforementioned features. The design algorithms obtain minimum weight frames by selecting suitable sections from a standard set of steel sections such as American Institute of Steel Construction (AISC) wide-flange (W) shapes. Stress constraints of AISC Allowable stress design (ASD) specification, maximum drift (lateral displacement) and interstorey drift constraints were imposed on the frames. The algorithms were applied to the optimum design of three space frame structures. The designs obtained using the two algorithms were compared to each other. The comparisons showed that the second algorithm resulted in lighter frames.

• Journal of the Korean Society for Precision Engineering
• /
• v.21 no.5
• /
• pp.83-83
• /
• 2004

The analysis of relative pose(position and rotation) between stereo cameras is very important to determine the solution that provides three-dimensional information for an arbitrary moving target with respect to robot-end. In the space of free camera-model, the rotational parameters act on non-linear factors acquiring a kinematical solution. In this paper the general solution of active stereo that gives a three-dimensional pose of moving object is presented. The focus is to achieve a derivation of linear equation between a robot′s end and active stereo cameras. The equation is consistently derived from the vector of quaternion space. The calibration of cameras is also derived in this space. Computer simulation and the results of error-sensitivity demonstrate the successful operation of the solution. The suggested solution can also be applied to the more complex real time tracking and quite general and are applicable in various stereo fields.

• Journal of the Korean Society for Precision Engineering
• /
• v.21 no.5
• /
• pp.89-90
• /
• 2004

The analysis of relative pose(position and rotation) between stereo cameras is very important to determine the solution that provides three-dimensional information for an arbitrary moving target with respect to robot-end. In the space of free camera-model, the rotational parameters act on non-linear factors acquiring a kinematical solution. In this paper the general solution of active stereo that gives a three-dimensional pose of moving object is presented. The focus is to achieve a derivation of linear equation between a robot's end and active stereo cameras. The equation is consistently derived from the vector of quaternion space. The calibration of cameras is also derived in this space. Computer simulation and the results of error-sensitivity demonstrate the successful operation of the solution. The suggested solution can also be applied to the more complex real time tracking and quite general and are applicable in various stereo fields.

• Advances in nano research
• /
• v.13 no.5
• /
• pp.453-463
• /
• 2022

This paper aims to investigate the vibration analysis of functionally graded porous (FGP) beams using State-space approach with several classical and non-classical boundary conditions. The materials properties of the porous FG beams are considered to have even and uneven distributions profiles along the thickness direction. The equation of motion for FGP beams with various boundary conditions is obtained through Hamilton's principle. State-space approach is used to obtain the governing equation of porous FG beam. The comparison of the results of this study with those in the literature validates the present analysis. The effects of span-to-depth ratio (L/h), of distribution shape of porosity and others parameters on the dynamic behavior of the beams are described. The results show that the boundary conditions, the geometry of the beams and the distribution shape of porosity affect the fundamental frequencies of the beams.