• 반도체디스플레이기술학회지
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• 제18권3호
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• pp.12-18
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• 2019

The protective double layer polymer coatings on silica optical fibers are realized by wet-on-wet liquid coating process and they play an important role in final quality of mass produced optical fibers. This numerical study aims to analyze the effects of secondary coating die design parameters by employing two dimensional axisymmetric model of coating cup and coating die geometry and computational fluid dynamics simulations which include temperature dependent viscosity of polymer coating liquids and viscous dissipation heating. Under high speed fiber drawing conditions and pressurized coating liquid supply, the effects of converging die angle are investigated in order to appreciate the change of coating liquid flow patterns such as flow recirculation zone near coating die as well as primary and secondary coating layer thicknesses. The auxiliary coating die to converging coating die is also tested and the results find that this concept is advantageous in achieving stable double layer coatings on silica glass fiber.

• 한국조경학회지
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• 제22권1호
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• pp.135-148
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• 1994

When we put a construction on the space organization form of Seyeon-jong garden through a consequence of drawing analysis, we were able to certify that a certain space construction principle was applied as following. First, the arrangement and organization of space construction element embodied systematic order y clearing the character of space, and heightening the degree of cognizance with the means of functionability, scale, height, decorationability, an inclination of artificiality and nature, systemetic approchability. Second, the space construction element of Seyeon-jong garden pursued a harmony of human work and nature for creating a various atmosphere and visual quality. Third, Seyeon-jong garden constructed the space by establishing the measurement of human scale that introduced a conception of near, middle, distant view on the visual angle. Forth, Yun go san introduced the natural shape of 'The song of five friends' as a construction element, and represented the symbolism that he had seeked for throught he arrangement method, christening, composing technique of the space construction element for expressing ideal space which is described in 'The four season song of fishermen' spatially at Seyeon-jong garden. As the results of this study, that Yun go san created his own ideal space that he longed for at Seyeon-jong garden with applying fixed design system, and he realized his will that he strived to form a complete whole in perfect harmony.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 춘계학술대회 논문집
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• pp.201-204
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• 2008

In this paper, several process parameter studies of the manufacturing process of the steel cords are carried out to verify the relation between the process parameters and the residual stresses on the steel cords. At first, the finite element analysis of the drawing process is performed and the residual stress distributions with respect to the wire material and the area reduction ratio are obtained. The residual stress of the drawn wire is imported the finite element analysis of the twisting process as an initial stress. After that a parameter study of the twisting process is carried out. The process parameters are the applied tension, the over-twisting angle and the tensile strength of the drawn wire. Based on these studies, the optimum values of the process parameters which can remove or reduce the undesired residual stresses are determined. The optimum value of the process parameters are confirmed by the finite element analysis of the elastic recovery process of the steel cords. Finally, the finite element analysis of the roller straightening process is done to study the variation of the distribution of the residual stress before and after the process.

• 한국정밀공학회지
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• 제17권8호
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• pp.198-206
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• 2000

This paper describes a research work of developing automated progressive process planning system for working electric products. An approach to the CAD system in based on the knowledge-based rules. Knowledge for the CAD system is formulated from plasticity theories experimental results and the empirical knowledge of field experts. The system has been written in AutoLISP on the AutoCAD with a personal computer and is composed of three main modules which are input and shape treatment flat pattern layout and strip layout module. Based on knowledge-based rules the system is design by considering several factors such as radius and angle of bend material and thickness of product complexities of blank geometry and punch profile bending sequence and availability of press. Strip layout drawing automatically generated by piercing with punch profiles divided into for external area is simulated in 3-D graphic forms including bending sequences for the product with piercing and bending. Results obtained using the modules enable the manufacture of electronic products to be more efficient in this field.

• 한국정밀공학회지
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• 제16권11호
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• pp.174-182
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• 1999

This paper describes a research work of developing a computer-aided design of product with bending constraints and piercing for progressive working. an approach to the CAD system is based on the knowledge-based rules. Knowledge for the CAD system is formulated from plasticity theories, experimental results and the empirical knowledge of field experts. The system has been written AutoLISP on the AutoCAD with a personal computer and is composed of four main modules, which are input and shape treatment, flat pattern layout, production feasibility check, and strip-layout module. Based on knowledge-based rules, the system is designed by considering several factors, such as radius and angle of bend, material and thickness of product, complexities of blank geometry and punch profile, bending sequence, availability of press. Strip layout drawing generated by piercing with punch profiles divide into automatically for external area is shown into graphic forms, including bending sequences for the product with piercing and bending constraints. Results obtained using the modules enable the designer and manufacturer of piercing and bending dies to be more efficient in this field.

• 한국자원식물학회지
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• 제21권3호
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• pp.216-221
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• 2008

The Purpose of this study was to offer the raw data for drawing up the conservation plan by analysing natural vegetation in Midongsan, Chungcheongbuk-do, Korea. The period of survey was from July to October, 2004 and the size of plot was 100$m^2$. In the results of analyzing the physical environments, the range of altitude was 303${\sim}$550m and soil pH was 5.4${\sim}$6.8. The angle of slope was 3${\sim}$57% and topographical factor was composed of ridgeline. In the results of analyzing a importance percentage, the dominant species in tree layer, Pinus rigida, P. densiflora, Quercus mongolica, Q. variabilis and Q. acutissima, P. rigida, Q. mongolica, Q. acutissima, Platycarya strobilacea and Q. variabilis in subtree layer, Rhododendron mucronulatum, Symplocos chinensis for pilosa, Lindera obtusiloba, L. erythrocarpa, Rhus trichocarpa and Weigela subsessilis in shrub layer. In the results of species diversity index, species diversity (H') was from 1.2401 to 2.5540, maximum species diversity (H'max), from 1.9459 to 2.8904, evenness (J'), from 0.5644 to 0.8836, dominance (D), from 0.1164 to 0.4356.

• Journal of Contemporary Eastern Asia
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• 제18권1호
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• pp.124-152
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• 2019

Smart city, which employs information and communication technology (ICT) to resolve urban problems, is gaining more research attention in the innovation research. However, most previous studies regard citizens as merely passive accepters of the smart city services, focusing on individual private values. The present study aims to expand existing limited perspectives by applying public value management theory. Drawing from the literature review, we developed a dual perspective that a smart city service should encompass: private and public value. Then we set up a causal relationship between the value recognitions and intention to adopt smart city services. We further related antecedent variables to the dual value recognition in terms of citizens' characteristics: prior knowledge, personal innovativeness, and citizenship. Two case subjects among currently operating smart city services in South Korea were selected to empirically investigate our hypothesis. Results confirm the recognition of both public and private value is significantly related to the citizens' personal characteristics and resultant attitude towards acceptance and support for diffusion of the smart city services. This study is expected to provide useful implications for a new angle for the recipient of the smart city services, value orientation of the services, citizen's participation, and method selection for promotion.

• 폴리머
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• 제35권4호
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• pp.337-341
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• 2011

수직배향 액정디스플레이의 시야각 향상을 위한 광대역 보상필름을 개발하였다. 상용화된 수직배향 액정디스플레이는 측면 시야각을 보상하는 위상차 필름을 필요로 한다. 일반적으로 triacetylcellulose(TAC)에 광학첨가제를 첨가한 후 제막연신을 통하여 수직배향 액정디스플레이용 위상차 필름을 제작하는데, 첨가되는 광학첨가제의 화학구조에 따라 필름의 위상차와 파장분산 특성이 달라진다. 본 연구에서는 첨가제에 따른 분극률 이방성을 양자역학적으로 계산하고 선택된 중심 이성질체에 사이드 그룹을 치환시켜 파장별 분극률 이방성을 또한 계산하였다. 특히, 치환기가 methoxy와 proplonate인 경우에 치환위치와 숫자에 따른 파장별 분극률 이방성을 비교하였다. 2개의 propionate 그룹이 meta위치에 있을 경우가 파장분산 특성이 가장 완만한 것을 양자역학적 계산을 통하여 예측하였으며 이를 실험을 통해 증명하였다. 파장분산 특성이 완만하다는 것은 LCD 시야각 특성이 광원의 파장에 따라 덜 변한다는 의미이며, 현재 수준보다 우수한 화질을 구현할 수 있다.

• 대한수학교육학회지:수학교육학연구
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• 제18권3호
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• pp.391-405
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• 2008

탱그램이라고 불리는 전통적인 칠교판(도형판)에 대한 기존의 연구들도 학교수학의 내용을 바탕으로 한 활동의 가능성에 초점을 두고 있다. 현행 수학과 교육과정에서 탱그램을 언급하고 있기는 하지만 교과서의 활용에서 탱그램의 유용한 특성을 제대로 반영하지 못할 뿐만 아니라 교육과정상의 다른 내용과 제대로 연결을 시키지 못하고 있다. 이에 본 연구는 초등학교 수학 교과서와 익힘책에 제시하고 있는 탱그램 사용이 교육과정과의 관련에서 갖는 문제점과 한계를 분석하면서, 학교 현장에서 바르게 활용할 수 있는 방안(제대로 그리기, 모양이 아닌 다각형 만들기, 수학적사고와 관련하여 현 교육과정의 수준에 적합한 활동분석, 교육과정의 한계를 넘나들며 활용할 수 있는 수준별 도형 탐구의 예시 등)과 유사탱그램까지 좀 더 확장하여 보다 적극적으로 활용할 수 있는 대안을 제안하였다.

• 한국의류학회지
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• 제34권1호
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• pp.50-66
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• 2010

This Shanghai region study is a sample survey of female college students in their early 20s. This study collected and analyzed the information of shapes through a direct contact survey to understand the breast figures and the measurements of bodies to provide basic information to improve brassiere production for adult females in China. Data was analyzed through a SAS 9.0. The characteristic of the final brassiere pattern that had been corrected and complemented from the results of the $l^{st},\;2^{nd},\;3^{rd}$, and $4^{th}$ fitting tests is defined as a brassiere inserted with a round wire that has the 3/4cup to wrap the bust area by about 3/4. It consists of an upper and lower nonwoven fabric cup that has a flat-shaped wing of a circular dart. The drawing method of the pattern of this brassiere is applied with the conditions to cover the body naturally under the diverse and organic relations of the material factor of stretch material and wire, functional factor, and sewing factor. The final pattern is created as a bigger angle of wing pattern and a short inner side diameter because there are more Chinese women with a back of bending figure compared to Korean women.