• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1999년도 춘계학술대회 논문집
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• pp.153-158
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• 1999

In the multi-purpose lathe, the design of tilting turret slide system has an important and critical role to enhance the accuracy of the machining process. Tilting turret unit is traveled by 3-axis slide systems. There is a need to design this part very carefully. In this research, the 3-axis slide system with tilting turret unit is modeled and simulated using ADAMS software. The dynamic behavior of this system is visualized by data graphs and dynamic animations. The first step of virtual prototype which makes it possible to design economically and effectively is developed.

• 천문학회보
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• 제43권1호
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• pp.68.4-69
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• 2018

GMACS is one of the instruments for the Giant Magellan Telescope (GMT) which will provide wide field, multi-object, moderate resolution spectroscopy of faint targets. KHU (Kyung Hee University) is in charge of control software of GMACS. As a first step, the Slit Mask Exchange Mechanism Prototype (SMEM-P) will be used as a preliminary example to make development process between electronics and high level software. Recently, we have developed a sample program to communicate with low level devices via EtherCAT. It is expected to be a mockup design for software and control system of GMACS. In this poster, we show the development process and test operation results of control software for SMEM-P.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1997년도 추계학술대회 논문집
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• pp.935-938
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• 1997

Recently, the minimum line width shows a tendency to decrease and the multi-level increase in semiconductor. Therefore, a planarization technique is needed and chemical mechanical polishing(CMP) is considered as one of the most suitable process. CMP accomplishes a high polishing performance and a global planarization of high quality. But there are several defects in CMP such as micro-scratches, abrasive contaminations, and non-uniformity of polished wafer edges. Wet etching include of Spin-etching can improve he defects of CMP. It uses abrasive-free chemical solution instead of slurry. On this study, ILD(INterlayer-Dielectric) was removed by CMP and wet-etching methods in order to investigate the superiority of wet etching mechanism. In the thin film wafer, the results were evaluated at a viewpoint of material removal rate(MRR) and within wafer non-uniformity(WIWNU). And pattern step height was also compared for planarization characteristics of the patterned wafer.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 1998년도 춘계 학술대회논문집
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• pp.181-189
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• 1998

A numerical study based on the three-dimensional Reynolds averaged Navier-Stokes equations is presented to analyze the transonic flowfield through two-stage axial compressor. Explicit four-step Runge-Kutta scheme is used for solution algorithm, and local time step and implicit residual averaging are introduced for enhancing the convergency. Artificial dissipation model is adopted to assure the stability of solution. The solver is coupled with Baldwin-Lomax model to describe turbulence. To avoid calculating the unsteady flow, a mixing process is modeled at a station between rotating and stationary blade rows. Results show a variety of important physical phenomena. Comparison of the flowfields with and without tip clearance shows that the effect is considerable in this flowfield. Comparisons with experimental data carried out to validate the calculational results show reasonable agreements. Some remedies are also suggested to improve the revealed problems.

• 한국음향학회지
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• 제22권6호
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• pp.434-442
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• 2003

특정한 언어 (영어)로 구현된 소프트웨어를 다른 언어 (한국어, 중국어 등)에서 처리할 수 있도록 하는 과정인 소프트웨어의 국제화는 음성기술 분야에 적응할 때 매우 복잡해진다. 그 이유는 음성 자체가 언어와 많은 연관 관계를 갖기 때문이다. 그러나 어떠한 언어라 해도 그 나라의 언어표현은ASCII코드나 혹은 그 나라 고유의 코드 기반으로 소프트웨어를 처리한다. 영어의 경우는 ASCII코드의 코드체계로 이루어지지만 다른 나라 언어인 경우 다른 형태의 언어코드를 사용하는 것이 일반적이다. 음성 처리에서 언어의 본질적 특성은 어휘모델에 나타난다. 어휘모델은 문자집합, 음소집합, 발음규칙으로 구성된다. 본 논문에서는 다국어 음성인식처리를 위한 어휘모델을 자동으로 생성하기 위하여, 4단계로 나누어 처리하는 어휘모델 구축 방법을 제안한다. 우선 전처리 과정으로 특정한 언어로 표현한 단어를 유니코드로 변환한다. (1단계) 유니코드로부터 중간 형태 코드로의 변환 (2단계) 발음 형태를 기본으로 하는 표준화된 규칙 적용 (3단계) 음소 규칙들에 의한 문자소 구현 (4단계) 음운론을 적용하는 순서로 구성된다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2007년도 추계학술대회 논문집
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• pp.289-292
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• 2007

To prevent the damage of glass lens molds and deterioration of glass lenses using in progressive GMP process, a thermal stress and a deformation of the glass lens molds at forming temperature should be considered in the design step. In this study, as a fundamental study to develop a multi cavity mold used in an aspheric glass lens molding, a heat transfer and a thermal stress analysis were carried out for the case of one cavity glass lens mold used in progressive GMP process. Finally, using analysis results, we estimated the thermal stress in a glass lens mold and predicted a modified height of guide ring that determines the forming height of a glass lens.

• 한국분말재료학회지
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• 제9권4호
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• pp.203-210
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• 2002

A new PIM in-process joining technique has been developed for more complicated and functional PIM components by application of the exuded wax from the green compacts during solvent debinding step. At first, various stainless steels and iron compacts with rectangular shape were combined, and the joining behaviors and properties were investigated by shear and tensile test, and microscopic observation. Subsequently, perfect joined three pieces of thin and hollow compacts were obtained for the combination of same and different stainless steels, and it was difficult to join the iron and stainless steel compacts in hydrogen atmosphere because of the different starting temperature of shrinkage. However, pretty good joined iron and stainless steel compacts were obtained by consideration of particle size and vacuum atmosphere. Finally, for the combination of ferro-silicon and austenitic stainless steel compacts, high functionality (magnetic (1.60Tes1a) & non-magnetic) and perfect joint were obtained.

• 한국표면공학회지
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• 제55권6호
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• pp.417-424
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• 2022

This research develops an easy-to-use, environmentally friendly method for fabricating functional 1050 aluminum alloy surfaces with excellent corrosion resistance. Functional aluminum surfaces with various nanostructures are fabricated by controlling the experimental conditions of anodizing process. The experiment used a multi-step anodizing process that alternates between two different anodizing modes, mild anodizing (MA) and hard anodizing (HA), together with a pore-widening (PW) process. Among them, the nanostructured surface with a small solid fraction shows superhydrophobicity with a contact angle of more than 170° after water-repellent coating. In addition, the surface with superhydrophobicity is difficult for corrosive substances to penetrate, so the corrosion resistance is greatly improved.

• 한국태양에너지학회 논문집
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• 제27권3호
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• pp.161-167
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• 2007

Zero Energy Multi-House(ZeMH) signifies a residential building which can be self sufficient with just new and renewable energy resources without the aid of any existing fossil fuel. For success of ZeMH, various innovative energy technologies Including passive and active systems should be well integrated with a systematic design approach. The first step for ZeMH is definitely to minimize the conventional heating and cooling loads over 50% with major energy conservation measure and passive solar features which are mainly related to building design components such as super-insulation, super window, including infiltration and ventilation issues. The purpose of this study is to analyze the thermal effect of various building design components in the early design of ZeMH. The process of the study is presented in the following. 1) selection reference model for simulation 2) verification of reference model with computer simulation program(ESP-r 9.0). 3) analysis of effect according to insulation-thickness, kinds of windows, rate of infiltration. and The simulation results indicate that almost 50% savings of conventional heating load in multi-house can be achieved with the optimum design of building components such as super insulation, super window, infiltration, ventilation.

• 제어로봇시스템학회논문지
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• 제19권4호
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• pp.364-371
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• 2013

Emotion Recognition is one of the important part to develop in human-human and human computer interaction. In this paper, we have focused on the performance of multi-class SVM (Support Vector Machine) with Gaussian RFB (Radial Basis function) kernel, which has been used to solve the problem of emotion recognition from physiological signals and to improve the accuracy of emotion recognition. The experimental paradigm for data acquisition, visual-stimuli of IAPS (International Affective Picture System) are used to induce emotional states, such as fear, disgust, joy, and neutral for each subject. The raw signals of acquisited data are splitted in the trial from each session to pre-process the data. The mean value and standard deviation are employed to extract the data for feature extraction and preparing in the next step of classification. The experimental results are proving that the proposed approach of multi-class SVM with Gaussian RBF kernel with OVO (One-Versus-One) method provided the successful performance, accuracies of classification, which has been performed over these four emotions.