• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1995년도 춘계학술대회논문집
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• pp.196-202
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• 1995

Drawbead formulation is the first process together with a binder wrap process in a sheet metal forming process. The purpose of a drawbead is to control the flow of the metal into the die in panel press forming. To simulate the drawbead formation process, an elasto-plastic finite element formulation is derived from the equilibrium equation an drelated boundary conditions considering the proper contact conditons. The developed finite element program is applied to drawbead formation in the plane strain condition. The simulation of drawbead formation produces the distribution fo stress and strain along the bead and the resultant elongation of the sheet in the cavity region with respect to various cavity dimensions of the sheet as well as the punch force of a drawbead and the amount of draw-in with respect to the stroke fo a drawbead. The numerical resutls provides the fundamental information as a boundary condition to analyze the complex binder wrap phenomena and panel press forming in simple way.

• Interaction and multiscale mechanics
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• 제6권2호
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• pp.237-255
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• 2013

In this paper, a meshfree-enriched finite element method (ME-FEM) is introduced for the large deformation analysis of nonlinear path-dependent problems involving contact. In linear ME-FEM, the element formulation is established by introducing a meshfree convex approximation into the linear triangular element in 2D and linear tetrahedron element in 3D along with an enriched meshfree node. In nonlinear formulation, the area-weighted smoothing scheme for deformation gradient is then developed in conjunction with the meshfree-enriched element interpolation functions to yield a discrete divergence-free property at the integration points, which is essential to enhance the stress calculation in the stage of plastic deformation. A modified variational formulation using the smoothed deformation gradient is developed for path-dependent material analysis. In the industrial metal forming problems, the mortar contact algorithm is implemented in the explicit formulation. Since the meshfree-enriched element shape functions are constructed using the meshfree convex approximation, they pose the desired Kronecker-delta property at the element edge thus requires no special treatments in the enforcement of essential boundary condition as well as the contact conditions. As a result, this approach can be easily incorporated into a conventional displacement-based finite element code. Two elasto-plastic problems are studied and the numerical results indicated that ME-FEM is capable of delivering a volumetric locking-free and pressure oscillation-free solutions for the large deformation problems in metal forming analysis.

• 소성∙가공
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• 제3권1호
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• pp.84-96
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• 1994

Simulation of 3 dimensional large irregularly shaped stamping process by a dynamic approach, based on an explicit time integration scheme, has been shown to be highly efficient and robust in comparison to traditional, implicit, quasi-static ones. The objective of the work is to evaluate the results from explicit code in application to deep drawing of rectangular cup and stamping of automotive front fender, in which deformation, force, thickness distribution are calculated. The method of predicting spring back and formability by and explicit code are suggested and applied to the processes.

• 전자공학회논문지A
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• 제28A권12호
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• pp.46-52
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• 1991

A new signal process circuit using two ISFETs as the input devices of the MOS differential amplifier stage for an ISFET biosensor has been developed. One chip integration of the newly developed signal process circuit, ISFETs and a Pt quasi-reference electrode has been carried out according to modified LOCOS p-well CMOS process. The fabricated chip showed gains of 0.8 and 1.6, good liniarity in the input-output relationship and very small power dissipation, 4mW. The chip was applied to realize a urea sensor by forming an immobilized urease membrane, using lift-off technique. on the gate of an ISFET. The urea sensor chip showed stable responses in a wide range of urea concentrations.

• 대한기계학회논문집A
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• 제22권2호
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• pp.380-390
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• 1998

In the present work a finite element formulation using dynamic explicit time integration scheme is used for numerical analysis of auto-body panel stamping processes. The lumping scheme is employed for the diagonal mass matrix and linearizing dynamic formulation. A contact scheme is developed by combining the skew boundary condition and direct trial-and-error method. In this work, for economic analysis the faster punch velocity and the mass scaling method are introduced. To investigate the effects of punch velocity and mass scaling, the various values of punch velocity and the various mass scalings are used for numerical analysis. Computations are carried out for analysis of complicated auto-body panel stamping processes such as forming of an oil pan and a fuel tank.

• Journal of Microbiology and Biotechnology
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• 제12권4호
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• pp.535-543
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• 2002

Although the generic implementation of aqueous two-phase systems (ATPS) processes for the recovery of biological products has been exploited for several years, this has not resulted in a wide adoption of the technique. The main reasons involve the poor understanding of the mechanism governing phase formation and the behavior of solute partitioning in ATPS processes, the cost of phase forming polymers, and the necessary extended time to optimize the technique. In this review paper, some of the practical disadvantages attributed to ATPS are addressed. The practical approach exploited to design ATPS processes, the application to achieve process integration, the extended use for the recovery of high-value products, and the recent development of new low-cost ATPS, are discussed. It is proposed that the trend of the practical application of ATPS processes for the recovery of biological products will involve the purification of new high-value bioparticulate products with medical applications. Such a trend will give new impetus to the technique, and will draw attention from industries needing to develop new, and improve existing, commercial processes.

• International Journal of Computer Science & Network Security
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• 제21권8호
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• pp.13-16
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• 2021

The article defines the hypothesis of the research, it is an assumption that the process of forming ICT competence will be effective if: theoretically substantiated, developed and practically implemented a structural and functional model for the formation of ICT competence, taking into account interdisciplinary integration, the pedagogical conditions that contribute to the formation of ICT competence have been determined: interdisciplinary integration as the basis for building an interdisciplinary course, the content of which is aimed at the formation of ICT competence.

• International Journal of Advanced Culture Technology
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• 제11권1호
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• pp.204-211
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• 2023

Chinese figure painting is the earliest type of painting to be mature in the history of Chinese painting. After its peak in the Jin and Tang dynasties, Chinese figure painting turned into a low tide in the Ming and Qing dynasties. Under the influence of the May Fourth New Culture Movement's concept of "introducing the Western culture into China", realistic ink wash figure painting emerged, which was different from traditional painting. Realistic ink wash figure painting is a new kind of painting that combines traditional Chinese painting methods with concepts of Western scientific painting. With the mutual reconciliation of realistic modeling and traditional Chinese painting, it makes up for the shortcomings of traditional Chinese figure painting in reproducing life, thus forming the diversified development of Chinese figure painting. Through an in-depth interpretation of the fusion of Chinese realistic ink figure painting with Chinese and Western, this paper accurately grasps the characteristics of the painting language, which is an important guide to the creation of Chinese realistic ink painting today.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1994년도 추계학술대회 논문집
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• pp.173-181
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• 1994

Process design is one of the most important fields in metal forming, where the finite element method has appeared a useful method for industrial applications. In this study, a program using the rigid plastic finite element has been developed for preform design in three-dimensional plastic deformation. The surface integration for calculation of the friction between die and workpiece has been implemented with care in numerical treatment. The developed program is applied to a precision coining process for designing an optimal punch.

• 해양환경안전학회지
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• 제17권3호
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• pp.275-281
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• 2011

선박의 건조 공정 중 병목공정에 해당하며 전적으로 숙련자의 수작업으로만 이루어지는 공정이 곡가공 공정이다. 이러한 곡가공 공정을 자동화 하고자 산업계와 학계의 많은 노력이 경주되었다. 기존의 곡가공 자동화 시스템 개발은 산업계와 학계에서 오랜 동안 연구되어 왔음에도 불구하고 실제로 생산현장에 투입되어 성공적으로 운영되는 사례는 없었다. 본 연구는 이러한 기존 곡가공 자동화 시스템 개발의 문제점을 파악하고 이를 해결할 수 있는 대안으로 요구사항 정의, 시스템 설계, 하부시스템 및 구성요소의 구현, 시스템 통합 및 검증의 4단계 시스템 엔지니어링 기반의 시스템 개발방법론을 제안하였다. 제안된 개발방법론을 기반으로 선체 곡가공 자동화 시스템 프로토타입 개발에 적용하고 결과를 고찰하여 기존 곡가공 자동화 시스템 개발에서의 문제점을 해결할 수 있는 대안이 될 수 있음을 확인하였다.