• Journal of the Korean Society for Heat Treatment
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• v.21 no.4
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• pp.189-198
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• 2008

The production of automotive chassis parts requiring both high hardness and good shape-holdability is better realized by using press quenching technology, comprising the austenitizaton and the subsequent press quenching in a specially designed stamping tool. The effect of press quenching mold shape on the hardness distribution, bending height, and degree of planeness of automotive flexible plate during press quenching and tempering has been investigated. The preferable shape of the projections of punch and die in contact with the flexible plate was close to oval to improve the flow of cooling oil, leading to the higher hardness. The press quenching mold with three separate parts was more effective to control the dimensional change due to thermal deformation during press quenching. Some decrease in the bending height during tempering may be related to some recovery of the residual stress at $400^{\circ}C$.

• Journal of the Korean housing association
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• v.7 no.1
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• pp.117-126
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• 1996

The purpose of this paper is to develop formal design principles towards flexible house plan. A flexible house plan accomodates spatial requirements corresponding to change of life style and provides a way of saving architectural materials. Design properties as a basis for manipulation of room includes adjacency, orientation and geometrical information which are suited well to flexible design. This paper has developed a formal grammar of shape which can be utilized to transform house plan. Flexible design presented here is based on the idea of various operations of the shape grammar. The shape grammar, as a set of rules, specifies manipulations of shapes for reorganization of spatial relationships of rooms in a house plan. It lists exemplary rules in control knowledge which guides design processes for modifying a plan. An example taken from house plan design is used to ilustrate important aspects of the flexible design which fundamentally provides the basis for architectural material saving.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.6
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• pp.2720-2728
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• 2012

Recently flexible mobile terminals which can freely change the shape of their device are coming out with the development of the flexible display, high capacity memory and system integration technology. The display and the antenna configuration of the future terminals will be altered according to the QoS (quality of service) and the communication environment of users. In particular, we present the new emergence of a multimedia language for human and system to communicate over subjective concepts, intention of users. The intension of users is expressed by changing the shape of their mobile terminal. In addition, antenna configuration is also related to shape of terminal and QoS of users. Therefore, we set up a specific usage scenarios for future mobile terminals and propose an adaptive MIMO (multiple-input multiple-output) schemes that can maximize channel capacity and fit to QoS of users simultaneously.

• Journal of the Society of Naval Architects of Korea
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• v.57 no.2
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• pp.61-69
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• 2020

Due to its flexibility of the composite propeller blade, it is necessary to design a shape capable of generating a desired load at a design point in consideration of the shape change of the propeller. In order to design it, we need to evaluate not only the hydrodynamic force around it, but also its structural response of flexible propeller according to its deformation. So, it is necessary to develop a design tool to predict the hydroelastic performance of a flexible propeller with deformation considering fluid-structure interaction and special operating conditions. Finally a design optimization tool for flexible propellermade of CFRP is required. In this study, a design methodology of the specific flexible composite propeller is suggested, considering fluid-structural interaction analysis of the specific flexible propeller.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.5
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• pp.3-11
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• 2018

Since the tensegrity structure is flexible and variable, the study on the mobility to the tensegrity has been conducted. However, it is difficult to apply the tensegrity to the architecture field due to several limits. This paper describes the methodology for the analysis of the shape change process of single prism tensegrity structure as an initial study. To apply the tensegrity structure to the architectural field, the assemblage and mathematical formulation procedures of the single prism tensegrity structures are carried out. And single prism tensegrity are presented to the computational strategies for simulate the shape change of those structures. Next, the investigation of structural behaviors through various cases of target displacements is described. Also, the summary of these methods in algorithms is illustrated. As a result it is confirmed that the single prism tensegrity structure model converges 99% on average to a given target node by using the proposed algorithm. Therefore, it is confirmed that the proposed algorithm and program are suitable for shape change analysis of single prism tensegrity structure model.

• Structural Engineering and Mechanics
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• v.6 no.2
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• pp.173-183
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• 1998

In the shape design of flexible structures, it is useful to predict the initial shape from the desirable large deformed shapes under some loading conditions. In this paper, we present a numerical procedure of an initial shape determination problem for hyperelastic materials which enables us to calculate an initial shape corresponding to the prescribed deformed shape and boundary condition. The present procedure is based on an Arbitrary Lagrangian-Eulerian (ALE) finite element method for hyperelasticity, in which arbitrary change of shapes in both the initial and deformed states can be treated by considering the variation of geometric mappings in the equilibrium equation. Then the determination problem of the initial shape can be formulated as a nonlinear problem to solve the unknown initial shape for the specified deformed shape that satisfies the equilibrium equation. The present approach can be implemented easily to the finite element method by employing the isoparametric hypothesis. Some basic numerical results are also given to characterize the present procedure.

• Journal of Biomedical Engineering Research
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• v.19 no.5
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• pp.519-530
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• 1998

In this paper, the basic study on the design of the flexible keel of the energy-storage prosthetic foot was performed in order to Improve the walking performance and Increase the activities of the below knee amputees. Based on the analysis of the anthropometric data and the normal gait on two dimensional sagittal plane available In the literature, we presented a model of the basic structure of the flexible keel of the prosthetic foot. The model of the basic structure was composed of the simple beams, and linear rotational spring and damper. Laminated carbon fiber-reinforced composites were selected as the material of the basic structure model of the flexible keel In order to apply the high strength and light weight materials to the basic structure of the flexible keel of the prosthetic foot. The recoverable strain energy In response to the change of beam shape was calculated bur the finite element analysis and it was suggested that the change of beam shape could be the design variable in flexible keel design. The simulation process was systematically designed by using orthogonal array table in order to design the flexible keel structure which could store the more recoverable strain energy. finite element analysis was carried but according to the design of simulations by using the finite element program ABAQUS and the flexible keel structure of the energy-storage prosthetic foot was obtained from the analysis of variance(ANOVA). The dynamic simulation model of the prosthetic walking using the flexible keel structure was made and the dynamic analysis was carried but during one walk cycle. Based on the above results, an effective design process was presented for the development of the prosthetic fool system.

• Journal of Sensor Science and Technology
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• v.30 no.3
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• pp.181-184
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• 2021

Interest in healthcare and wearable devices has been increasing recently. A strain sensor is required in various wearable devices. With respect to such devices, studies on resistance changes in strain sensors using flexible materials are in progress. However, the resistance of the rest area in a strain sensor should not change according to the applied strain. So, an electrode with resistance to stretching, bending, and torsion is required in such strain sensors. Tension, bending, and torsion can be realized through structural shape control, rather than by using flexible materials. Further, such an electrode that maintains electrical properties has been developed and manufactured. This electrode can be used in various applications such as foldable devices, e-papers, batteries, and multifunctional wearable devices.

• Journal of Technologic Dentistry
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• v.30 no.2
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• pp.47-56
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• 2008

This is a research for thickness change of denture base according to the shape of sprue & investment position of denture base in flask when injecting polyamid base resin for flexible partial denture as a part of study for Valplast among the flexible partial denture with a nylon base. It has been introduced several kinds of flexible partial denture product with a nylon base, but Valplast is the most widely used product among them. Valplast has been the most generally used material today since developed in 1950s in the United States as a material for flexible partial denture. Valplast is much more aesthetic than general metal-acrylic partial denture due to its translucent pink color and biocompatibility in terms of material characteristic. It keeps its flexibility for a long time after production, imposes a less burden on the teeth used as abutment, and it can be easily insert and remove due to its particular suppleness. Moreover, it is felt like real teeth more than metal-acrylic partial denture when being put in and takes alveolar bone under good protection since it receives occlusal force equally under the denture base. The most outstanding feature of Valplast is flexibility. The extent of its flexibility is determined by width & thickness of denture base. Considering general working procedure of Valplast, it can be seen that the thickness of denture base formed out of wax is increasing by the pressure while injecting resin. This research is to decide and test on the thickness increasing of Valplast by injecting pressure and the hypothesis upon that and is to prepare the basis estimating the increasing extent of thickness of denture base on the basis of the test result. In this test, it is expected occlusal malposition & thickness increasing of denture base by injecting pressure according to 4 kinds of test data which are to select 3 types of sprue method settling the forefront position at which the test material of fixed standard can be invested and to position the test material at the rearmost part keeping the minimum distance to set sprue. For 4 kinds of injecting test by investment position & sprue type, 20 test materials, 5 for each test were produced and a pressure of 1,180Kg was given with automatic injector of air cylinder type. The results are as follows: 1. For the amount of thickness increasing of denture base by investment position, the thickness of front investment is less increasing than the one of rear investment. 2. For the amount of thickness increasing of denture base by sprue type, the thickness of straight decompression sprue type which can absorb the injecting pressure after injecting polyamide base resin is less increasing than the other sprue types.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.1167-1172
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• 2007

Generally inpipe robot needs force above standing for contacting robot to pipe. If the environment of the pipe-inside does not change, there is not a problem. But if the pipe radius change, or occur the obstacle which it does not intend, problem gets. So it uses a different system and must know an environment change, and changing the shape or a form of the robot. The research uses the flexible leg and is the robot which is adapted to the environment change of the pipe. The advantage of this robot is possible to move when it does not need to recognize a change of environment of pipe. Leg is bend with one direction. When it moves part that there are legs effect of leg direction the robot is moved with only one direction. If friction between legs and pipe is sufficient, not only verticality pipe moving, but also curved pipe moving. Also the obstacle of the pipe inside occurs and the diameter of the pipe inside changes, this robot can move if it does not use another system or device.