• Journal of Aerospace System Engineering
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• v.14 no.2
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• pp.28-35
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• 2020

In this paper, we present a design for a retraction-type actuator (ReACT) that has the characteristics of both thermomechanical metamaterials and displacement amplification mechanisms. The ReACT consists of an actuating bar, a diamond-shaped displacement amplification (DA) structure, and a slot for loading thin-film heaters formed through the actuating bar. When power is supplied to the thin film heater, the actuating bars contacting the heater thermally expand, and the diamond-shaped DA structures retract in the longitudinal direction. The performance characteristics of the ReACT, such as temperature distribution and retracting displacement, were calculated with thermomechanical analysis methods using the finite element method (FEM). Subsequently, the ReACTs were fabricated using a polymer-based 3D printer that can easily execute complex structures, and the performance of the ReACT was evaluated through repeated tests under various temperature conditions. The results of the performance evaluation were compared with the results of the FEM analysis.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2002.04a
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• pp.385-392
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• 2002

Derivation procedures of exact elastic element stiffness matrix of thin-walled curved beams are rigorously presented for the static analysis. An exact elastic element stiffness matrix is established from governing equations for a uniform curved beam element with nonsymmetric thin-walled cross section. First this numerical technique is accomplished via a generalized linear eigenvalue problem by introducing 14 displacement parameters and a system of linear algebraic equations with complex matrices. Thus, the displacement functions of displacement parameters are exactly derived and finally exact stiffness matrices are determined using member force-displacement relationships. The displacement and normal stress of the section are evaluated and compared with thin-walled straight and curved beam element or results of the analysis using shell elements for the thin-walled curved beam structure in order to demonstrate the validity of this study.

• Journal of Korea Game Society
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• v.9 no.6
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• pp.171-178
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• 2009

Multiple layer displacement mapping methods are able to represent more complex and general geometries which cannot be presented by single layer displacement mapping methods, and provide a realistic scene to digital contents such as 3D games and movies with relatively low costs. However, as we use more layers for details, data space is wasted more because lower layers have less displacement data than higher layers. In this paper, we suggest a lossless compression and rendering method of a multiple layer displacement map. Since we compress the map without data loss, the proposed method provides the same quality as the rendering result that uses an original multiple layer displacement map.

• The korean journal of orthodontics
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• v.15 no.2
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• pp.211-227
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• 1985

The purpose of this study was to analyze the stress distribution and the displacement in the maxillary complex after the application of the three kinds of the head gear. (high pull head gear, straight pull head gear, cervical pull head gear.) Orthopedic force, 300 gram, was applied to the maxilla of the dry human skull in a high, straight and cervical direction. The stress distribution and the displacement within the maxillary complex was analyzed by a 3-dimensional finite element method. The results were as follow: 1. In won, the stress of conical pull head gear was the greatest stress and straight pull head gear was the medium stress and high pull head gear was the least stress. 2. The compressive stress was observed on the anterior portion of premaxilla, especially anterior nasal spine area, when the three kinds of head gear were applied to the dry kuman skull. 3. It appeared that the stress of the anterior portion of the zygomatic bone was greater than the posterior portion in the case of three kinds of head gear application and compressive stress was noted only at the below of the frontozygomatic suture of the zygomatic bone. 4. The backward, upward, sideward displacement of the alveolar area was observed in a high pull head gear application but in the case of straight pull head gear and cervical pull head gear application, the backward, downward, sideward displacement was observed. 5. The forward, downward, sideward displacement was observed on the midpalatine suture and premaxilla on the sagittal plane and transverse palatine suture in the case of three kinds of headgear application.

• Structural Engineering and Mechanics
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• v.53 no.2
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• pp.205-226
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• 2015

Finite element method (FEM) is an effective quantitative method to solve complex engineering problems. The basic idea of FEM for a complex problem is to be able to find a solution by reducing the problem made simple. If mathematical tools are inadequate to obtain precise result, even approximate result, FEM is the only method that can be used for structural analyses. In FEM, the domain is divided into a large number of simple, small and interconnected sub-regions called finite elements. FEM has been used commonly for linear and nonlinear analyses of different types of structures to give us accurate results of plane stress and plane strain problems in civil engineering area. In this paper, FEM is used to investigate stress analysis of a shear wall which is subjected to concentrated loads and fundamental principles of stress analysis of the shear wall are presented by using matrix displacement method in this paper. This study is consisting of two parts. In the first part, the shear wall is discretized with constant strain triangular finite elements and stiffness matrix and load vector which is attained from external effects are calculated for each of finite elements using matrix displacement method. As to second part of the study, finite element analysis of the shear wall is made by ANSYS software program. Results obtained in the second part are presented with tables and graphics, also results of each part is compared with each other, so the performance of the matrix displacement method is demonstrated. The solutions obtained by using the proposed method show excellent agreements with the results of ANSYS. The results show that this method is effective and preferable for the stress analysis of shell structures. Further studies should be carried out to be able to prove the efficiency of the matrix displacement method on the solution of plane stress problems using different types of structures.

• Journal of architectural history
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• v.7 no.4 s.17
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• pp.49-60
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• 1998

The first aim of this paper is to investigate and analyze Alan Colquhoun's architectural hermeneutics of tradition, 'conceptual displacement of the past.' The second aim is to overcome the limit of it, and to suggest new architectural hermeneutics of tradition, 'the reactivation of the past.' The architectural work is reduced by Colquhoun to typology or arbitrary language because he believes that without arbitrary language natural language is not able to work effectively. However, he ignores that two languages cannot be separable. When they are separated the key to natural language is understood to be an unverifiable similarity between a sense perception and its correspondence in the architectural object, while the key to arbitrary language becomes mere artificial agreement on the value and function of the linguistic sign. Therefore, natural language is appropriate only when it permits spontaneous combinations of sensory data within complex structures which emerge from, and support, complex human interaction and communication(the shining of the world and of the possibility of creative being in each individual thing). Only when architecture is translated into this kind of language, can it reactivate the world's past, and become poetic.

• Journal of Drive and Control
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• v.16 no.1
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• pp.36-44
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• 2019

Variable displacement swash plate piston pump analysis requires electric, hydraulics and dynamics which are similar to the one's incorporated in the complex fluid power and mechanical systems. The main variable capacity for the swash plate piston pumps, hydraulics or simple kinematic (swash plate degree, piston displacement) models are analyzed using AMESim, a multi-physics analysis program. AMESim is a multi-physics hydraulic analysis program that is considered good for the environment but not appropriate for environmental analysis for multibody dynamics. In this study, the analytical model of the swash plate type hydraulic piston pump variable capacity is modeled by combining the hydraulic part and the dynamic part through co-simulation of multibody dynamics program (Virtual.lab Motion) and multi-physics analysis (AMESim). This paper describes the whole modeling analysis method on the mechanical analysis of the multi-body dynamics program and how the hydraulic analysis in multi-physics analysis program works. This paper also presents a methodology for analyzing complex fluid power systems.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.10
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• pp.1500-1508
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• 2004

Stress and displacement fields for a crack propagating along interface between isotropic material and functionally gradient one with linear property gradation along X direction are developed. The stress and displacement fields are obtained from the complex function of steady plane motion for isotropic and functionally gradient material (FGM). The stresses and displacement in isotropic material of bimaterial are not influenced by nonhomogeneity, however, the fields in FCM are influenced by nonhomogeneity in the terms of higher order, n$\geq$3. When the nonhomogeneous parameter in FGM is zero, or in area close to crack tip, the fields are identical to those of isotropic-isotropic bimaterial. Using these stress components, the effects of nonhomogeneity on stresses are discussed.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1-4
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• 1996

It is difficult that a non-translational motion in a block is estimated by the block matching algorithm (BMA). In this paper, a nodal-displacement-based deformation model is used for this reason. This model assumes that a selected number of control nodes move freely in a block and that displacement of any interior point can be interpolated from nodal displacements. As a special case with a single node this model is equivalent to a translational model. And this model can represent more complex deformation using more nodes. We used an iterative gradient based search algorithm to estimate nodal displacement. Each iteration involves the solution of a simple linear equation. This method is called the deformable block matching algorithm (DBMA).

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.7
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• pp.807-818
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• 1988

This paper proposes new algorithms for the estimation of displacement vector and moving object extraction using difference picture. First, the relations between the boundary of moving objects in two consecutive image and the boundary of difference picture regions are analyzed, then displacement vector estimation algorithm is proposed. Using the estimated displacement vector, moving objects are directly extracted from difference picture. Since the proposed algorithms do not process gray-valued image, they have a short processing time and are suitable to real time processing. From the experimental results, we observed that, if difference picture is wel extracted, the proposecd algorithms work well even in the circumstances of complex background, fast or slow motion, rotation etc., including occlusion where is not moving area.