• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 B
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• pp.537-539
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• 1998

In this paper, we construct the on-line model structure for the nonlinear process systems using the adaptive fuzzy-neural network. Adaptive fuzzy-neural network usually consists of two distinct modifiable structure, with both, the premise and the consequent part. These two parts can be adapted by different optimization methods, which are the hybrid learning procedure combining gradient descent method and least square method. To achieve the on-line model structure, we use the recursive least square method for the consequent parameter identification of nonlinear process. We design the interface between PLC and main computer, and construct the monitoring and control simulator for the nonlinear process. The proposed on-line modeling to real process is carried out to obtain the effective and accurate results.

• Geomechanics and Engineering
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• 제22권3호
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• pp.245-254
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• 2020

The interaction between the frozen soil and building structures deteriorates with the increasing temperature. A nuclear magnetic resonance (NMR) stratification test was conducted with respect to the unfrozen water content on the interface and a shear test was conducted on the frozen soil-structure interface to explore the shear characteristics of the frozen soil-structure interface and its failure mechanism during the thawing process. The test results showed that the unfrozen water at the interface during the thawing process can be clearly distributed in three stages, i.e., freezing, phase transition, and thawing, and that the shear strength of the interface decreases as the unfrozen water content increases. The internal friction angle and cohesive force display a change law of "as one falls, the other rises," and the minimum internal friction angle and maximum cohesive force can be observed at -1℃. In addition, the change characteristics of the interface strength parameters during the freezing process were compared, and the differences between the interface shear characteristics and failure mechanisms during the frozen soil-structure interface freezing-thawing process were discussed. The shear strength parameters of the interface was subjected to different changes during the freezing-thawing process because of the different interaction mechanisms of the molecular structures of ice and water in case of the ice-water phase transition of the test sample during the freezing-thawing process.

• 한국수학교육학회지시리즈A:수학교육
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• 제61권2호
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• pp.273-286
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• 2022

본 연구의 목적은 교사와 학생 간의 의사소통을 바탕으로 수학 문제를 해결하는 과정에서 교사의 담론 구조를 분석하는 것이다. 이러한 목적 달성을 위해 학생들의 수업 참여를 바탕으로 수학적인 의미들을 만들어 가는 교수법을 다년간 실행한 경력 교사의 한 학기 수업을 관찰하였다. 한 학기 수업 중에서 주어진 문제를 해결하기 위해 담론의 구조를 만들어가는 과정들 간의 공통점을 분석하였다. 분석 결과 교사는 담론을 시작하는 과정에서는 목표에 집중을 할 수 있도록 하였고, 담론을 전개하는 과정에서는 문제 이해에 초점을 두고 문제를 해결하였으며, 담론을 정리하는 과정에서는 문제 해결 과정과 결과에서의 핵심을 요약하였다. 교사 담론 구조의 일반화 가능성을 바탕으로 향후 학생들과 소통하여 수학 문제를 해결하는 교수법을 실행하는 과정에 실질적인 도움을 줄 수 있을 것이다.

• 건축역사연구
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• 제25권3호
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• pp.23-35
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• 2016

The purpose of this study is to classify types of the eaves structure of buildings with the Jusimpo-type structure and to analyze the characteristics of each eaves structure. For this objective, forty buildings were selected and investigated. The results of analysis are summarized as follows. First, the main members of framework which handle a load burden on the long-rafter(長椽) are classified as the Jusim-dori(柱心道里) and the Oemok-dori(外目道里). Based on the method of handling a load, the eaves structure is classified into three types; the Jusim-processing-type(柱心中心形), the Oemok-processing-type(外目中 心形), and the Oemok-processing-variant-type(外目中心變異形). The Jusim-processing-type is the set where the internal length of a long-rafter is longer than the length of the eaves on the basis of the center of a column. The Oemok-processing-type is the set where the external length of a long-rafter is longer than the internal length of it. And the Oemok-processing-variant-type is the set where the internal length of a long-rafter is longer than the external length of it, but it is shorter than the length of the eaves which includes the extruded length of a Buyeon(浮椽). Second, the Jusim-processing-type had been generally adopted in the Jusimpo-type structure of the Goryeo Dynasty. But since the 17th century, the Oemok-processing-type had the highest application rate. Third, the change from the Jusimdori-processing-structure to the Oemokdori-processing-structure means that the long-rafter is moved to the direction of outside of the building, and thus the Jung-dori(中道里) is gradually moved to the column center. And, the change of the eaves with the Jusimpo-type structure was not a process for increasing the length of the eaves but a process for adopting the advantages of the Dapo-type structure by changing the arrangement of purlin. Fourth, the change from the Jusimpo-type structure to the Dapo-type structure could be understood as a process for moving the main point for handling a load from the Jusim-dori to the Oemok-dori.

• Design & Manufacturing
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• 제2권1호
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• pp.15-19
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• 2008

While recent industrial structure is various, it is small quantity batch production structure, and products requiring of various functions are increasing. In order to improve the quality of the sheared surface in cutting of inner structure bonded sheet metal the cut-off operation is mainly investigated, which is the typical shearing process in sheet metal forming technology. The sandwich sheet metals considered have inner structure which is constructed in the form of crimped expanded metal and woven metal. The inner structure is bonded between solid sheet by resistance welding or adhesive bonding. The shearing process is visualized by the computer vision system installed in front of the cut-off die and the sheared surface is measured and quantitatively compared with the help of the optical microscope after cut-off operation. From test results we found that the influence of sheared position can be observed and explained clearly and this result can be utilized to get the better sheared surface.

• Structural Engineering and Mechanics
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• 제86권1호
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• pp.93-107
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• 2023

In this paper, a density based topology optimization is proposed for generating of supports required in additive manufacturing to maintain the overhanging regions of main structures during layer by layer fabrication process. For this purpose, isogeometric analysis method is employed to model geometry and structural analysis of main and support structures. In order to model the problem two cases are investigated. In the first case, design domain of supports can easily be separated from the main structure by using distinct isogeometric patches. The second case happens when the main structure itself is optimized by using topology optimization and the supports should be designed in the voids of optimum layout. In this case, in order to avoid boundary identification and re-meshing process for separating design domain of supports from main structure, a parameterization technique is proposed to identify the design domain of supports. To achieve this, two density functions are defined over the entire domain to describe the main structure and supporting areas. On the other hand, since supports are under gravity loads while main structure and its stiffness is not completed during manufacturing process, in the proposed method, stiffness of the main structure is considered to be trivial and the gravity loads are also naturally applied to design support structures. By doing so, the results show reasonable supports are created to protect, continuously, overhanging surfaces of the main structure. Several examples are presented to demonstrate the efficiency of the proposed method and compare the results with literature.

• 한국공간구조학회논문집
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• 제2권1호
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• pp.51-58
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• 2002

Construction of roof structure, cable suspended structure, for Pusan main stadium is adapted a lifting method that is VSL lifting system. 5 processes are practiced for erection of the roof structure including the first lifting process for erection of upper cables and the second lifting process for erection of lower cables. Since all cables of this roof structure with two open spelter sockets are determined their length, some cable were wrong length, he roof structure would be unstable. But, At complete of erection for the roof structure each cable is attained to theoretical tension force with average 4% errors.

• Architectural research
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• 제17권1호
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• pp.31-40
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• 2015

A simple force-finding process based on an optimization technique is proposed for tensegrity structures. For this purpose, the inverse problem of form-finding process is formulated. Therefore, the position vector of nodes and element connectivity information are provided as priori. Several benchmark tests are carried out to demonstrate the performance of the present force-finding process. In particular, the force density distributions of simplex tensegrity are thoroughly investigated with the important parameters such as the radius, height and twisting angle of simplex tensegrity. Finally, the force density distribution of arch tensegrity is produced by using the present force-finding process for a future reference solution.

• JSTS:Journal of Semiconductor Technology and Science
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• 제3권3호
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• pp.107-113
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• 2003

Microelectronics device performance and its reliability are directly related to and controlled by its constituent materials and their microstructure. Specific processes used to form and shape the materials microstructure need to be controlled in order to achieve the ultimate device performance. Examples of front-end and back-end ULSI processes, packaging process, and novel optical storage materials are given to illustrate such process-structure-property-reliability relationship. As more novel materials are introduced to meet the new requirements for device shrinkage, such under-standing is indispensable for future generation process development and reliability assessment.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2006년도 춘계학술대회 논문집
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• pp.377-380
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• 2006

Manufacturing process of Ti-6Al-4V alloy billet was investigated with FEM simulation and experimental analysis. Before the breakdown process of Ti-6Al-4V alloy ingot, FEM simulation for the breakdown processes of Ti-6Al-4V alloy ingot was used to calculate the forging load and state variables such as strain, strain rate and temperature. In order to breakdown the ingot structure and make an equiaxed structure billet, two different processes were employed for a VAR/VAR processed Ti-6Al-4V alloy ingot. Firstly, the ingot was cogged in single-phase $\beta$ field at the temperature of $1,100^{\circ}C$. In the process, the coarse and inhomogeneous structure developed by the double melting process was broken down. The second breakdown was performed by upsetting and cogging processes in $\alpha+\beta$ phase field to obtain the microstructure of fine equixed $\alpha$ structure in the matrix of transformed $\beta$. Finally, the mechanical properties of Ti-6Al-4V alloy billet made in this work were compared with those of other billet and ring product.