• Journal of Advanced Marine Engineering and Technology
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• 제18권3호
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• pp.1-9
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• 1994

The transient temperature distribution of materials during upsetting forming is very important for quality of upsetted workpiece and understanding the thermal characteristics of upsetting is essential for optimum control of the forming. In this paper it is shown that the governing equation of heat transfer for axi-symetric body can be derived from minimizing a functional, and from this theory, formulation of analysis by the finite element method is presented. It is also shown that the thermal contact resistance between two bodies can be represented by equivalent coefficient of heat conductivity. Some examples of calsulated transient temperature distributions by the computer program diveloped from the theory presented in this paper are given in graphic forms. It is proven that the results calculations are very plausible.

• 기술경영경제학회:학술대회논문집
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• 기술경영경제학회 2000년도 제17회 하계학술발표회 논문집
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• pp.153-173
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• 2000

This study is focused on measuring levels of science and technology aspect of ten strategic items in korea to serve as a guidance for the government R&D policy-making, and provide appropriate information for promoting the national R&D programs. The survey of the precise technology level for study applies functional and technical parameters. Functional parameters are used for measuring technology level of the specification and performance of emerging items such as 256M DRAM, TFT-LCD ect. in the present and / or near future; technical parameters, the element / core technologies on emerging items. The study suggests that the result of the survey should be applied for strategic technology planning to narrow the technology gap and draw the criteria for resource allocation in national R&D programs.

• Journal of Microbiology and Biotechnology
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• 제18권1호
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• pp.107-109
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• 2008

Medicinal fungi, Phellinus linteus and Inonotus xeranticus, produce a cluster of yellow pigment in their fermentation broth that acts as an important element of biological activity. The pigment is composed of diverse polyphenols with a styrylpyrone moiety, mainly hispidin and its dimers, 3,14'-bihispidinyl, hypholomine B, and 1,1-distyrylpyrylethan. Although dimeric hispidins were proposed to be biosynthesized from two molecules of monomer via oxidative coupling by ligninolytic enzymes, laccase and peroxidase, the details of this process remain unknown. In this preliminary study, we attempted to achieve enzymatic synthesis of the hispidin dimer from hispidin by using commercially available horseradish peroxidase (HRP). Consequently, a hispidin dimer, 3,14'-bihispidinyl, was synthesized, whereas the other dimers, hypholomine B and 1,1-distyrylpyrylethan, were not produced. This result suggested that the oxidative coupling at the C-3 and C-14' positions of hispidins was dominant in the process of dimerization by HRP, and indicated that additional catalysts or substrates would be needed to synthesize other hispidin dimers present in the fungal metabolite.

• 전기의세계
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• 제30권4호
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• pp.219-226
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• 1981

The magnetic field distribution in saturable iron part of electromagnetic energy conversion divices is defined by the nonlinear quasi-Poisson enquation that is described the electromagnetic field characteristics and satisfied the natural boundary condition. The solution of this equation is obtained by minimizing an energy functional by means of trial function that defined in triangular subregion of two-dimensional field region. As a result, the accuracy of the machine design is increased by use of its solution. In this respect, this study is developed the basic theory to analyze the magnetic flux distribution in saturable iron part and air gap of induction motor that its secondary part is short circuit by the variational principle, the minimized theory of energy functional, the application of F.E.M., and treatment of computer. As theoritical data compared with the practics, the validity of the theory in this study is supported by experimental findings.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 심포지엄 논문집 정보 및 제어부문
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• pp.80-82
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• 2004

Personal robot consist of various modules that have independent functions. Because personal robot has requirement that support various construction for user's tendency. Therefore, Middleware mechanism at support not only personal robot's main functional element but also embedded modules functional elements is required. Each module have various heterogeneous network interfaces and variable services and variables. Therefore, Middleware must support these various network interfaces. This paper, pointed in Controller Area Network(CAN) inreface that usually used in embedded system for control. For connect various heterogeneous network interfaces (Ethernet, RS232 etc..), it is necessary to modify bagic CAN frame format. And also make some kind of BUS topology for CAN network.

• 한국산학기술학회논문지
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• 제13권10호
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• pp.4405-4410
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• 2012

본 논문의 목적은 제과제빵기계인 다기능 도우 컨디셔너의 열전달 해석에 있다. 도우 컨디셔너는 제과제빵의 원료인 생지(dough)를 숙성시키는 중요한 기계로서 사용량이 증가하고 있다. 새로운 형태의 다기능 도우 컨디셔너를 제작하기 위하여 자동 설계프로그램인 Solidworks를 활용하여 설계하였으며 이를 근거로 3차원 유한요소 해석코드인 ANSYS를 활용하여 열전달 해석을 수행하였다. 해석결과로서 다기능 도우 컨디셔너의 내부온도와 열유속을 구하였으며 이 결과는 다기능 도우 컨디셔너의 제작에 활용되었다.

• 한국미생물·생명공학회지
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• 제36권2호
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• pp.149-157
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• 2008

Many proteins consist of distinctive domains that can act independently or cooperatively to achieve a unique function. As these domains evolve from a naturally existing repertoire of functional domains, this implies that domain organization is an intrinsic element involved in building the complex structure and function of proteins. Thus, identifying functional domains would appear to be critical to the elucidation of questions related to protein evolution, folding, and the engineering of hybrid proteins for tai- lored applications. However, the simple application of "Lego-like assembly" to the engineering of hybrid proteins is an oversimplification, as many hybrid constructs lack structural stability, usually due to unfavorable domain contacts. Thus, directed evolution, along with computational studies, may help to engineer hybrid proteins with improved physico-chemical properties. Accordingly, this paper introduces several approaches to functional hybrid protein engineering that potentially can be used to create modulators of gene transcription and cell signaling, and novel biosensors to analyze biological functions in vivo.

• Smart Structures and Systems
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• 제13권4호
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• pp.501-515
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• 2014

This paper presents a linear computational homogenization framework to evaluate the effective (or generalized) electromechanical coupling coefficient (EMCC) of adaptive structures with piezoelectric structural fiber (PSF) composite elements. The PSF consists of a silicon carbide (SiC) or carbon core fiber as reinforcement to a fragile piezo-ceramic shell. For the micro-scale analysis, a micromechanics model based on the variational asymptotic method for unit cell homogenization (VAMUCH) is used to evaluate the overall electromechanical properties of the PSF composites. At the macro-scale, a finite element (FE) analysis with the commercial FE code ABAQUS is performed to evaluate the effective EMCC for structures with the PSF composite patches. The EMCC is postprocessed from free-vibrations analysis under short-circuit (SC) and open-circuit (OC) electrodes of the patches. This linear two-scale computational framework may be useful for the optimal design of active structure multi-functional composites which can be used for multi-functional applications such as structural health monitoring, power harvest, vibration sensing and control, damping, and shape control through anisotropic actuation.

• 한국정밀공학회지
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• 제22권7호
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• pp.164-169
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• 2005

The micro-gripper system is one of the systems that should be improved in the respect of performance for practical usage. In the previous works, the important issues are considered and presented using axiomatic design approach. In this paper, the functional requirements and design parameters are evaluated in order to improve the performance and efficiency of the system. The evaluation is a very difficult task since many variables are related to the outcomes. To provide a basis for correct design decisions, axiomatic design principles have been advanced. Since the framework of axiomatic design makes design issues easier to understand when they are analyzed, we used those as an evaluation tool. The object of the system is to handle micro-size parts. Main device is a micro-gripper using two bender-typed and one stack-typed PZTs as actuators. And it has three tips made of tungsten wires fur holding function. Also the system must satisfy other functional requirements for appropriate handling performance. The results of this study show design improvements of micro-gripper system such as structural change of gripper, additional element, and integration of physical parts. Axiomatic design guides presented suitable design parameters corresponding to functional requirements and made the design elements improve through diagrams of whole system.

• 한국생산제조학회지
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• 제25권5호
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• pp.313-320
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• 2016

The need for high-strength, multi-axis, and multi-functional machine tools has recently increased because of part complexity and workpiece strength. However, most of the machine tool manufacturers rely on experience for a detailed design because of the shortcomings in the existing design technology. This study uses a topology optimization method to more effectively design a large multi-functional machine tool considering static stiffness. The ram, saddle, and column parts are important structures in a machine tool. Hence, they are selected for the finite element method analysis. Based on this analysis, the optimized internal rib structure for those parts is designed for desirable rigidity and weight. This structure could possibly provide the required design technology for machine tool manufacturers.