• 설비공학논문집
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• 제13권5호
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• pp.422-430
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• 2001

In the present study, an evaporative generation process of ammonia-water solution film on the vertical plate was analysed. For the utilization of waste heat, hot water of low temperature was used as the heat source. The continuity, momentum, energy and diffusion equations for the solution film and vapor mixture were formulated in integral forms and solved numerically. Counter-current solution-vapor flow resulted in the refrigerant vapor of the higher ammonia concentration than that of co-current flow. Eve the rectification of refrigerant vapor was observed near the inlet of solution film in counter-current flow. For the optimum operation of generator using hot water, numerical experiments, based on the heat exchange and generation efficiencies. revealed the inter-relationships among the Reynolds number of the solution film and hot water, and the length of generator. Enhancement of heat and mass transport in the solution film was found to be very effective for the improvement of generation performance, especially at high solution flow rate.

• Bulletin of the Korean Chemical Society
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• 제30권1호
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• pp.97-101
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• 2009

A new approach was applied to examine the charge generation and transport in organic photoconductive devices by Monte‐Carlo simulation utilizing multiple site interactions of carriers with all other charges within Coulomb radius. Stepwise generation frame was considered first by a charge separation process that was counted in two separate transactions, i.e., hopping against physical decay and dissociation against recombination. Thereafter, diffusion/ drifting process of free carriers was counted to follow. This method enables to examine readily the photocurrent generated alongside the charge generation efficiency. The field and temperature dependences of the efficiency and photocurrent were obtained comparable to Onsager’s and experimental data.

• 한국기계가공학회지
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• 제2권3호
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• pp.26-33
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• 2003

The term 'High Speed Machining' has been used for many years to describe end milling with small diameter tools at high rotational speeds, typically 10,000-100,000rpm. The process was applied in the aerospace industry for the machining of light alloys, notably aluminum. In recent year, however, the mold and die industry has begun to use the technology for the production of components, including those manufactured from hardened tool steels. With increasing cutting speed used in modern machining operation, the thermal aspects of cutting become more and mole Important. It not only directly influences in rate of tool weal, but also affects machining precision recognized as thermal expansion and the roughness of the surface finish. Hence, one needs to accurately evaluate the rate of cutting heat generation and temperature distributions on the machining surface. To overcome the heat generation, we used to cutting fluid. Cutting fluid plays a roles in metal cutting process. Mechanically coupled effectiveness of cutting fluids affect to friction coefficient at tool-workpiece interface and cutting temperature and chip control, surface finish, tool wear and form accuracy. Through this study, we examined the behavior of heat generation in high-speed machining and the cooling performance of various cooling methods.

• 한국CDE학회논문집
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• 제7권3호
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• pp.148-156
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• 2002

Most Rapid Prototyping (RP) processes adopt a solid Computer Aided Design (CAD) model, which will be sliced into thin layers of constant thickness in the building direction. Each cross-sectional layer is successively deposited and, simultaneously, bonded onto the previous layer; and eventually the stacked layers from a physical part of the model. A new RP process, the transfer-type Variable Lamination Manufacturing process using expandable polystyrene foam sheet (VLM-ST), has been developed to reduce building time and to improve the surface finish of parts with the thick layers and a sloping surface. This paper describes the generation of Unit Shape Layer (USL), the cutting path data of the linen. hotwire cutter for the VLM-ST process. USL is a three-dimensional layer with a thickness of more than 1 mm and a side slope, and it is the basic unit of cutting and building in the VLM-ST process. USL includes data such as layer thickness, positional coordinates, side angles of each layer, hotwire cutting speed, the heat input to the hotwire, and reference shape. The procedure of generating USL is as follows: (1)Generation of the mid-slice from the CAD model, (2)Conversion of the mid-slice into a simply connected domain, (3)Generation to the reference shape for the mid-slice, (4)Calculation of the rotation angle of the hotwire of the cutting system.

• 한국콘텐츠학회논문지
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• 제22권4호
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• pp.207-221
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• 2022

기존의 '환경설계를 통한 범죄예방(Crime Prevention Through Environmental Design; CPTED)' 이론은 실천 과정에서 미흡함이 있었고, 이 때문에 통상적인 범죄예방 디자인 프로세스에는 한계점이 존재했었다. 본 연구의 목적은 디자인학의 관점에서 제3세대 CPTED 이론적 프레임워크와 더블 다이아몬드(Double Diamond Model) 디자인 프로세스 이 두 가지의 접목을 분석하는 것이다. 본 연구는 이를 통해, 더블 다이아몬드 디자인 프로세스가 접목된 가시적인 제3세대 CPTED 디자인 프로세스를 제시하고자 했다. 또한, 각 학자별로 제3세대 이론적 프레임워크에 대해 연구한 관련 논문을 각자의 주장, 목표, 전략 방법, 거주적합성 원칙(Liveability)에 따라 명확히 정리했다. 이를 바탕으로, 영국 디자인 위원회의 혁신을 위한 프레임워크를 결합하여, 제3세대 이론적 프레임워크와 더블 다이아몬드 디자인 프로세스의 접목에 명확한 기준과 기초를 마련했다. 또한, 단계적인 아웃풋과 활동 방식으로 양자 간의 접목에 대한 구체적 내용을 분석하고 설명했다. 연구의 의의는 더블 다이아몬드 디자인 프로세스와 가시적인 제3세대 CPTED 디자인 프로세스의 접목을 통해 거주민들의 자아 가치 실현 행동을 유도하고 이로 인한 참여(Engagement)를 돕는 것이다. 또한, CPTED 프로젝트에 참여한 디자인 관련 종사자 및 기타 분야 종사자의 협업에 참고가 될 수 있는 연구 결과를 도출하는 것이다.

• 한국CDE학회논문집
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• 제10권1호
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• pp.61-69
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• 2005

In the global ship structure and vibration analysis, the FE(finite element) analysis model is required in the early design stage before the 3D CAD model is defined. And the analysis model generation process is a time-consuming job and takes much more time than the engineering work itself. In particular, ship structure has too many associated structural members such as stringers, stiffness and girders etc. These structural members should be satisfied as the constraints in analysis modeling. Therefore it is necessary to support generation of analysis model with satisfying these constraints as an automatic manner. For the effective support of the global ship analysis modeling, a method to generate analysis model using initial design information within ship design process, that hull form offset data and compartment data, is developed. In order to easily handle initial design information and FE model information, flexible data structure is proposed. An automatic quadrilateral mesh generation algorithm using initial design information to satisfy the constraints imposed on the ship structure is also proposed. The proposed data structure and mesh generation algorithm are applied for the various type of vessels for the usability test. Through this test, we have verified the stability and usefulness of this system including mesh generation algorithm.

• 한국과학교육학회지
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• 제23권3호
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• pp.215-228
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• 2003

이 연구는 과학철학에서 논의되어온 과학의 선언적 지식의 생성 과정을 보다 체계적으로 분석하고 정리하여 하나의 구조화된 과학적 지식의 생성 모형을 제시하고자 하였다. 이를 위해, 이 연구는 선언적 과학 지식의 생성 과정을 과학철학적 관점들을 중심으로 다양한 문헌들을 분석하고, 이러한 분석 결과를 바탕으로 과학적 지식의 생성 모형을 체계적으로 구조화하였다. 이를 통해 고안된 모형은 귀납적 과정, 귀추적 과정, 연역적 과정 등으로 구분되는 지식 생성 과정을 포함한다. 또, 각각의 과정은 다시 여러 단계의 하위 과정으로 구성되어 있음을 보여준다. 이 모형에 의하면, 먼저 귀납적 과정은 관찰과 규칙성 발견 과정으로 구분되며, 다시 관찰은 단순관찰과 조작관찰로 나뉘고, 규칙성발견은 공통점발견, 분류, 위계 발견 등으로 세분된다. 그리고 귀추적 과정은 의문 생성과 가설생성 과정으로 구분되며, 여기에서 가설생성과정은 다시 의문상황 표상, 경험상황 동정, 원인적설명자동정, 가설적설명자 동정 등의 과정으로 나뉘어 진다. 마지막으로 연역적 과정은 방법 기준의 고안 과정은 다시 가설의 검증방법 고안과 가설의 평가기준 고안으로, 가설평가 과정은 결과수집 과정과 가설평가 및 결론 진출 과정으로 세분된다.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
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• pp.15-18
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• 2002

To achieve the global planarization, CMP Technology has been used to the next generation semiconductor process, and the study made tremendous progress up to date. As the device demension shrinked， CMP Technology has been applied in a various way and more people interested in this field to simplify the process. To attain the goal for safer 0.13um or below 10 nano process, many of those expected task must be solved. By describing this current CMP process issue and future trend for the CMP planarization process, It personally hope that this paper would help to the people who has concerns for the next generation semiconductor manufacturing industry in common.

• Tribology and Lubricants
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• 제28권1호
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• pp.7-11
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• 2012

In this paper, the results of finite element(FE) analysis of chemical mechanical polishing(CMP) process using 2-dimensional elements were discussed. The objective of this study is to find the generation mechanism of microscratches on a wafer surface during the process. Especially, a FE model with a particle inside pad pore was considered to observe how such a contact situation could contribute to microscratch generation. The results of the finite element simulations revealed that during CMP process the pad-particle mixture could be formed and this would be a major factor leading to microscratch generation.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2003년도 추계학술대회 및 정기총회
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• pp.74-78
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• 2003

In this paper, we have developed a technology-service relationship model which describes the diffusion process of a group of services and relevant technologies, and have applied the developed model to the prediction of the number of subscribers to the next generation mobile service. The technology-service relationship model developed in this paper incorporates the developing process of relevant technologies, a supply-side factor, into the diffusion process of specific services, while many diffusion models and multi-generation diffusion models in previous researches are mainly reflect the demand-side factors. So, the proposed model could effectively applied to the telecommunication services where the developing of the relevant technologies are very essential to the service penetration. In our application, the proposed model provides a competitive substitution between the next generation mobile service and the traditional mobile service.