• International Journal of CAD/CAM
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• 제6권1호
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• pp.183-192
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• 2006

A CAD/CAM system has been developed for rapid prototyping (RP) of microfluidic devices based on excimer laser micromachining. The system comprises of two complementary softwares. One, the CAM tool, creates part programs from CAD models. The other, the Simulator Tool, uses a part program to generate the laser tool path and the 2D and 3D graphical representation of the machined microstructure. The CAM tool's algorithms use the 3D geometry of a microstructure, defined as an STL file exported from a CAD system, and process parameters (laser fluence, pulse repetition frequency, number of shots per area, wall angle), to automatically generate Numerical Control (NC) part programs for the machine controller. The performance of the system has been verified and demonstrated by machining a particle transportation device. The CAM tool simplifies part programming and replaces the tedious trial-and-error approach to creating programs. The simulator tool accepts manual or computer generated part programs, and displays the tool path and the machined structure. This enables error checking and editing of the program before machining, and development of programs for complex microstructures. Combined, the tools provide a user-friendly CAD/CAM system environment for rapid prototyping of microfluidic devices.

• 동아시아경상학회지
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• 제7권4호
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• pp.1-13
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• 2019

Purpose - Based on transaction cost perspective and institution-based perspective, this research attempts to investigate the effect of outsourcing on a firm's performance and how it interacts with institutional context in which the firms operate. Research design, data, and methodology -With a sample of 164 manufacturing firms form South Korea, we examine the direct effects of outsourcing on the a firm's level of product innovation and internationalization and the moderating effects of competitive pressure and property right protection as important external factors that could affect the effectiveness of outsourcing decision. Result - The findings show that outsourcing not only enhance a firm's capability to concentrate on its core competencies, but also to increase a firm's combinative capacity to acquire external knowledge. Furthermore, we finds that in a highly competitive environment, potential knowledge spillovers to other competitors may attenuate the potential benefits of outsourcing. Conclusion - Outsourcing can enhance a firm's innovation activities by providing valuable access to external knowledge and also to complementary resources from the external partners, which in turn enables firms to focus on core competences.

• 한국전기전자재료학회논문지
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• 제25권1호
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• pp.6-14
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• 2012

For integrated complementary metal oxide semiconductor (CMOS) circuits, the lateral spread for two-dimensional (2-D) impurity distributions are very important for the analyzing the devices. The measured two-dimensional SEM data obtained using the chemical etching-method matched very well with the results of the Gauss model for boron implanted samples. But the profiles in boron implanted silicon were deviated from the Gauss model. The profiles in boron implanted silicon were shown a little bit steep profile in the deep region due to backscattering effect on the near surface from the bombardments of light boron ions. From the simulated 3-D data obtained using an analytical model, the 1-D and 2-D data were compared with the experimental data and could be verified the justification from the experimental data. The data of 3-D model were also shown good agreements with the experimental and the simulated data. It can be used in the 3-D chip design and the analysis of microelectro-mecanical system (MEMS) and special devices.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1399-1400
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• 2008

본 논문에서는 TSMC 0.18um 공정을 이용하여 2.45GHz 대역에서 동작하는 RFID 리더에 적용 할 수 있는 전압제어 발진기를 설계하였다. 위상 잡음 특성 향상을 위해 PMOS, NMOS 소자를 대칭으로 구성한 complementary cross-coupled LC 발진기 구조로 설계 하였고 MOS 배렉터를 이용하여 주파수를 가변 하였다. 또한 공정에서 사용되는 인덕터에 차폐 도체면(PGS:Patterned Ground Shield) 구조를 삽입했을 때 인덕터의 품질계수가 약 5.82% 향상되었고. 이에 따른 위상 잡음은 1MHz offset 주파수에서 PGS를 삽입하지 않는 구조에서는 -102.666dBc/Hz 이며, PGS 구조를 삽입한 구조는 -104.328dBc/Hz로 약1.662dBc 정도의 성능이 향상 되었다. 전압제어 발진기 Core 사이즈는 900um ${\times}$ 590um이고 주파수 가변 범위는 배렉터 전압 1.2${\sim}$2.1V에서 249MHz로 11.4% 특성을 보였다. 1.8V공급전압에서 5.76mW의 전력소모를 보였다.

• 유통과학연구
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• 제18권10호
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• pp.15-23
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• 2020

Purpose: Crowdfunding can be a complementary channel in which start-ups or small companies can obtain financial help and take advantage of exploiting the online potential. To activate crowdfunding, it is necessary to consider a consumer's empathic responses. This article examines the role of empathy in the crowdfunding channel platform. We adopted the identification-commitment model to prove the role of empathy. Research design, data, and methodology: Participants were asked to read the charitable crowdfunding campaign. More than 300 young adults completed an online questionnaire and we analyzed it with structural equation modeling (SEM). To find out the role of empathy, we postulate several models which use empathy variable for different purposes. Results: We conclude that empathy has the role of moderator in the identification-commitment model. This means the high empathic response helped the relationship between identification and commitment. However, low empathic response can negatively influence the process of identification to commitment. Conclusions: This study found that virtual empathy is positively related to crowdfunding participation if we can elevate empathy in the crowdfunding channel platform. The findings also show that we need to consider empathic response when we want to raise funds for specific projects such as protecting the natural environment.

• 한국멀티미디어학회논문지
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• 제7권11호
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• pp.1515-1520
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• 2004

본 논문에서는 저전압에서 동작이 가능하며 이득값이 뛰어난 능동소자를 이용하여 750kHz의 중심주파수특성을 나타내는 연속시간 대역통과 능동필터를 설계하였다. 이용된 적분기는 이득특성에 영향을 주는 트랜스컨덕턴스값을 증가시키기 위해 CMOS 상보형 캐스코드 방식을 이용하여 구성되었으며, 0.25$\mu\textrm{m}$ CMOS n-well 공정 파라미터를 이용한 hspice 시뮬레이션 결과, 2V 공급전압하에서 42dB의 이득값과 200MHz의 단위이득주파수 특성을 나타내었다. 또한 이를 이용하여 설계된 대역통과 능동필터는 747kHz의 중심주파수특성을 나타내고 659kHz의 대역폭 특성을 보여주었다.

• 한국정보통신학회논문지
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• 제13권6호
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• pp.1117-1122
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• 2009

본 논문에서는 온도 센서 및 온도 측정을 위한 제어회로를 설계하였다. 설계된 회로는 기존의 방법들과는 달리 일반적인 CMOS(Complementary Metal Oxide Semiconductor) 공정에서 추가 공정없이 제작 가능하도록 설계하였으며, 온도는 디지털 값으로 출력 되도록 구성하였다. 설계되어진 회로는 5volts 공급전압을 사용하였으며, 0.5${\mu}m$ CMOS 공정을 사용하였다. 온도 측정을 위한 회로는 PWM(Pulse Width Modulation) 제어회로, VCO(Voltage controlled oscillator), 카운터 그리고 레지스터로 구성되어 있다. PWM 제어회로의 동작 주파수는 23kHz 이며, VCO의 동작 주파수는 416kHz, 1MHz, 2MHz를 사용하였다. 회로의 동작은 SPICE(Simulation Program with Integrated Circuit Emphasis)를 사용하여 확인 하였다.

• 유통과학연구
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• 제14권3호
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• pp.23-30
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• 2016

Purpose - This research focuses on the analysis of logistics barriers in Korea, China and Japan facing the barriers of overseas-expanded manufacturers with other countries. With the tree countries are emerging as the biggest trade partners in Northeast Asia, their logistics barriers are applied with similar verification methods of preceding researches such as Carter(1997). Research design, data and methodology - Collecting the statistics data from the three countries' overseas-expanded manufacturers, t-verification was performed in order to analyze average value and verify any significance. Additionally, multiple regression analysis was used to analyze any influence on the relationship in Korean logistics barrier and Chinese and Japanese expansion to Korean market. Results - Statistics suggested that three countries' logistics barriers are significantly differentiated by each verification categories, and Korean barrier negatively affected Chinese and Japanese manufacturers coming into Korean market. Conclusions - As a result of multiple regression analysis of the influencing relationship between Korea's logistics barrier and Chinese and Japanese companies coming into Korean market, all of the Korean barriers are affecting the companies as an obstructive factor, and it is proved to be statistically meaningful. Therefore, in order to reduce Chinese and Japanese companies' cost burden, it is necessary that not only reasonable charge system and taxation support but also comprehensive measure establishment reduce Korea's logistics barriers. However, since this research has a limitation in samples and shows a period of 5 years in the three nations' trade barriers, continuous and complementary researches are necessary in order to develop certain objectivity.

• 공학교육연구
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• 제8권1호
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• pp.99-112
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• 2005

문제중심학습은 실세계 환경과 공학적 환경에서 탐구하고 문제 해결하는 실천적 학습에 중점을 두며, 크게 교육과정 조직자와 수업전략의 두 가지 전략을 포함한다. 이 연구에서 구안한 PBL 전략은 크게 교육과정 조직자로서의 문제설계 단계와 수업전략으로서의 문제 적용 단계로 구분된다. 특히 문제 적용 단계는 문제해결 학습에 기초하며, 그 절차는 즉 '문제의 확인', '문제의 구체화', '해결방안의 탐색과 창안', '해결방안의 선정', '해결방안의 구체화', '실행', '평가', '적용과 성찰'의 단계이다. 특히 이 연구에서 계획과정의 상세화는 문제해결 모형이 갖는 장점 중의 하나인 문제해결을 위한 구상, 즉 확산적 사고와 수렴적 사고활동을 유도하기 위한 전략의 방편이 된다.

• 한국주조공학회지
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• 제13권4호
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• pp.333-341
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• 1993

The effects of alloying elements on the structure and mechanical properties of compacted/vermicular graphite cast irons containing copper, tin and molubdenum for producing pearlite matrix, and also containing phosphorus and boron for increasing wear resistance, were investigated. The Brinell hardness and ultimate tensile strength of the specimens with the range of compositions, [1.5% Cu-0.05% Sn-(0.2-0.4)% Mo-(0.2-0.6)% P-(0.035-0.070)% B], was found to fall within in the following range, depending on their composition; Brinell hardness of BHN 250-315, ultimate tensile strength of $28.1-40.3kg/mm^2$. It was also found within this experiment that CV graphite cast irons possessing higher amount of phosphide eutectic exhibit better wear resistance, but the wear resistance became deteriorate when the area fraction of phosphide eutectics exceed more than 10%. From these experimental results, it could be concluded that the CV graphite cast iron containing 1.5% Cu, 0.05% Sn, 0.4% Mo, 0.2% P and 0.035% B showed good mechanical and wear resistance properties.