• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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• pp.1441-1444
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• 2008

We developed ultra-accelerated quantum chemical molecular dynamics and spectroscopic characterization simulators for development of PDP materials. By combination of these simulators, realistic structure of PDP materials is drawn on the computer. Furthermore, based on the structures, various properties such as cathode luminescence spectrum and secondary electron emission, is successfully evaluated. The strategy of "Experiment integrated Computational Chemistry" using developed simulators will presented that has the potential in being powerful tool for designing the PDP materials.

• 한국인터넷방송통신학회논문지
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• 제18권5호
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• pp.203-208
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• 2018

본 논문에서는 지진에 의해 발생 가능한 시설물의 피해 유형 중에서 도시기반시설에 해당하는 전력시설물과 배전시설물을 선정하였고 피해 여부를 산출해내는 방식에 대해 연구를 진행하였다. 피해여부를 산출하기 위해 시설물의 유형과 종류에 따라 취약률을 산출할 수 있는 취약률 곡선 산출식을 적용시켜 피해 규모에 따른 그래프를 산출해 내었다. 산출 결과를 활용하기 위해서 도시기반시설에 지진 발생 상황을 가정하고 지진의 규모와 최대지진가속도에 따른 피해 발생 확률을 취약률 형태로 나타내었다. 또한 산출된 취약률을 정수 형태로 변환하는 방식인 취약률 정량화 방식을 적용시켜 피해 규모에 대한 상수 값을 나타내었다. 본 논문에서 적용한 방식과 같은 연구가 지속될 경우 지진 발생 시 피해를 입는 시설물의 유형을 미리 파악하고 피해를 절감하기 위한 대응을 할 수 있을 것이다.

• 한국정보처리학회논문지
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• 제3권5호
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• pp.1103-1111
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• 1996

하드웨어와 통신 기술의 발달로 가능하게 된 분산처리 시스템은 수행 방식이 비결 정적이고 복잡하기 때문에 소프테웨어의 디자인이 비분산처리 시스템에 비해 복잡하고 또한 까다롭다. 따라서 하드웨어에 비해 상대적으로 뒤져있는 분산처리 시스템 소프 트웨어 개발을 위한 디자인 방법에 관한 연구에 대한 필요성이 높아지고 있다. 한편 객체향 시스템과 분산처리 시스템은 상호 유사한 점이 있어, 분산처리 시스템 개발에 객체지향 기술의 적용은 자연스럽게 이루어질 수가 있다. 본고에서는 분산에서는 분산처리 시스템 설계를 위한 객체지향 기술의 적용에 대하여 소개하고 있다. 제안된 설계방법은 다양한 그래픽 모델, 즉, 자료구조도, 상태전이도 그리고 패트리 네트의 정보를 조합하여 객체와 행위 그리고 이들 간의 관계에 대한 정보를 추출하여 분산 처리 시스템에 적합한 명세서를 산출하고자 한다. 지식베이스를 정보저장소로 이용 하여정보의 저장, 검색 뿐만 아니라, 정보의 오류 연구를 검증할 수가 있다. 본 방법의 최종 결과인 객체모델은 디자인 명세서로서 분산처리프로그램 개발에 사용된다.

• 대한전자공학회논문지
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• 제26권5호
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• pp.108-116
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• 1989

본 논문은 mixed level에서 VLSI회로의 논리설계를 검증하기 위한 논리 레벨 시뮬레이터인 LOSM(LOgic SIMulatos)에 대해서 논의한다. 본논문에서는 8개의 신호값과 2개의 신호강도를 이용하여 일반소자, 기능소자, transmission게이트 그리고 tri-state 게이트의 경우 종래의 시뮬레이터$^{[5~6,9]}$보다 정확한 결과를 얻을 수 있는 모델링 방법을 제안한다. LOSIM은 rise delay와 fall delay를 사용하여 주어진 회로에 대한 타이밍 분석과 hazard 분석이 가능하다. Hazard분석 및 검출은 5상태의 신호값과 time queue를 이용한 scheduled time을 이용한다. 개발된 알고리듬은 SUN-3/160 워크그테이션상에서 C-언어를 사용하여 구현되었으며, 정적 RAM셀과 비동기 회로에 대해서 프로그램의 동작 예재로 하였다.

• 천문학회보
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• 제37권1호
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• pp.31.2-31.2
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• 2012

We present the Yonsei Evolutionary Population Synthesis (YEPS) models for spectroscopic and photometric evolutions of simple and composite stellar populations. The models are based on the most up-to-date Yonsei-Yale stellar evolutionary tracks and BaSel 3.1 flux libraries, and provide integrated spectroscopic quantities of Lick/IDS system including high-order Balmer absorption-lines. Special care has been taken to incorporate the systematic variation of horizontal branch (HB) morphology as functions of metallicity, age, alpha-element mixture, and helium abundance of simple stellar populations. Our models for normal-helium stellar populations indicate that the realistic modeling of HB and alpha-element brings about 5 Gyr and 0.1 dex differences in age and metallicity estimations, respectively, compared to those without these effects. The HB effect does not depend on the specific choice of stellar libraries and alpha-element enhancements, and this effect is non-negligible even in the metal sensitive absorption indices, such as Mg2 and Mg b. Comparison of the models to observations reveals that the HB and alpha-element effects are critical in understanding otherwise inexplicable phenomena found in globular cluster systems in the Milky Way and nearby galaxies, including the observed bimodality of the line strengths of globular clusters in massive galaxies. In addition, we found that helium-enhanced stellar populations, which are the major sources of extreme HB stars, bring about increased FUV, NUV fluxes, and thus the model colors of those filters become extremely blue. Age dating based on the YEPS model with normal-helium stellar populations reveals that the evidence for 'downsizing' of elliptical galaxies is found not only in the local field but also in Coma cluster, and that the mean age of elliptical galaxies in Coma cluster is about 1.4 Gyr younger than the mean age of those in the local field. We also find that our models with helium-enhanced subpopulations can naturally reproduce the strong UV-upturns observed in giant elliptical galaxies assuming an age similar to that of old GCs in the Milky Way.

• 대한기계학회논문집A
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• 제21권5호
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• pp.819-827
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• 1997

In this paper, a new modeling of a fine actuator for an optical pick-up has been proposed and multiobjective optimization of the actuator has been performed. The fine actuator is constituted of the bobbin which is supported by wire suspension, the coils which wind around the bobbin, and the magnets which cause the magnetic flux. If current flows in the coils, magnetic force is so produced as to be balanced with spring force of wire, so the bobbin is pisitioned. In this model the transfer function from input voltage to output displacementof bobbin has been obtained so that we can describe this integrated system with electromagnetic and mechanical parts. Wire suspension is regarded as a continuous Euler beam, damper as distributed viscous damping, and bobbin as a rigid body which can move up- and down- ward motion only. According to the model, the high frequency dynamic characteristics of the fine actuator can be known and the effect of damping can be investigated while the conventional second order model cannot. In multiobjective optimization, two objective functions have been chosen to maximize the fundamental frequency and the sensitivity with respect to the input voltage of the actuator so that Pareto's optimal solutions have been obtained using .epsilon.-constraint method. These objective functions will satisfy the trends which will enhance the access speed and reduce the tracking error in the optical pick-up technology of next generation. In the result of optimization, we obtain the designs of the optical pick-up fine actuator which has high speed, high sensitivity and low resonant peak. Furthermore, we offer the relation between two object functions so that the designer can make easy choice.

• 한국기계가공학회지
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• 제14권3호
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• pp.15-20
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• 2015

After the US government declared 3D printing technology a next-generation manufacturing technology, there have been many practical studies conducted to expand 3D printing technology to manufacturing technologies, called AMERICA MAKES. In particular, the Keck Center, located at the University of Texas at El Paso, has studied techniques for easily combing the 3D stacking process with space mobility and expanded these techniques to simultaneous staking techniques for multiple materials. Additionally, it developed convergence manufacturing techniques, such as direct inking techniques, in order to produce a module structure that combines electronic circuits and components, such as CUBESET. However, in these studies, it is impossible to develop a unified system using traditional independent through simple sequencing connections. This is because there are many problems in the integration between the stacking modeling of 3D printers and post-machining, such as thermal deformations, the precision accuracy of 3D printers, and independently driven coordinate problems among process systems. Therefore, in this paper, the integration method is suggested, which combines these 3D printers and subsequent machining process systems through an Internet-based cloud. Additionally, the sequential integrated system of a 3D printer, an NC milling machine, machine vision, and direct inking are realized.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.768-771
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• 2003

The impulse between launch vehicle and atmosphere can generate a lot of noise and vibration during the process of launching a satellite. Structurally, electronic equipment (KOMPSAT 2, RDU : Remote Drive Unit) of a satellite consists of aluminum case containing PCB (Printed circuit boards). Each PCB has resistors and IC (Integrated circuits). Noise and vibration of wide frequency band are transferred to the inside of fairing, subsequently creating vibration of the electronic equipment of the satellite. In this situation. random vibration can cause malfunctioning of the electronic equipment of the device. Furthermore, when tile frequency of random vibration meets with natural frequency of PCB. fatigue fracture nay occur in the part of solder joint. The launching environment, thus. needs to be carefully considered when designing the electronic equipment of a satellite. In general. the safety of the electronic equipment is supposed to be related to the natural frequency, shapes of mode and dynamic deflection of PCB in the electronic equipment. Structural vibration analysis of PCB and its electronic components can be performed using either FEM(Finite Element Method) or vibration test. In this study. the natural frequency and dynamic deflection of PCB are measured by FEM, aud the safety of the electronic components of PCB is being evaluated according to the results. This study presents a unique method for finite element modeling and analysis of PCB and its electronic components. The results of FEA are verified by vibration test. The method proposed herein may be applicable to various designs from the electronic equipments of a satellite to home electronics.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.30-33
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• 2003

In this paper the advantage of web technology applied to Rapid Prototyping is discussed. Two fabrication processes are chosen to be web-enabled. One, a post-process of FDM is developed to provide translucent plastic parts made of medical grade ABS material. The other, a system to fabricate laser machined Light Guide Panel is developed. In order to show the timesaving characteristics of the web-based tools, two websites are implemented (http://nano.gsnu.ac.kr/fdm ＆ http://nano.gsnu.ac.kr/laser). The 3-tier architecture is applied for the Internet communication between designers and manufacturing sites, The integrated design tools and physical manufacturing processes enable designers to submit a new design and to receive the fabricated parts in an expedited manner. Example parts are fabricated using the web-based system to prove the concept of the web-based design and Rapid Prototyping.

• Fashion, Industry and Education
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• 제14권2호
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• pp.35-46
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• 2016

The purpose of this study was to examine female consumers' attitudes and purchase intentions toward intimate apparel brands. To understand female consumers' shopping behaviors for intimate apparel products, this study examined interrelationships among brand familiarity, perceived risk, attitudes, and purchase intentions toward intimate apparel brands. A conceptual model was developed by adopting perceived risk theory (Cox, 1967) and theory of reasoned action (Ajzen & Fishbein, 1980). A pre-survey using a paper and pencil was conducted to identify the most familiar intimate apparel brand to young female consumers. The majority of pre-survey respondents (66 female college students) indicated Victoria's Secret as the most prominent intimate apparel brand. Therefore, Victoria's Secret was used to examine possible effects of brand familiarity on perceived risk and attitudinal and behavioral responses toward the brand. Using a web-based survey, 384 complete responses were collected from young female college students between the ages of 18-29 at a Mid-southern U.S. university. A structural equation modeling was employed to test the proposed research model and hypotheses. Results showed positive, statistically significant associations among the four variables (e.g., brand familiarity, perceived risk, attitudes, and purchase intentions). The findings suggested that young female consumers who are familiar with a particular intimate apparel brand are likely to perceive a low level of risk, leading to positive, strong attitudes with purchase intentions toward that particular intimate apparel brand. This suggests establishing brand familiarity through integrated marketing communication is crucial for risk reduction strategy in intimate apparel shopping.