• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.47-49
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• 2008

This paper presents the vibration characteristic of interior type permanent magnet (IPM) motor according to rotor design. In the design methods, the optimal notchs are put on the rotor pole face, which have an effect on variation of permanent magnet (PM) shape or residual flux density of PM. Through the space harmonics field analysis, the positions of notch are found and the optimal shapes of notch are decided by using Finite Element Method (FEM). The validity of the proposed method is confirmed with experiments. Therefore, the vibration, starting current and efficiency of IPM is measured by experiment.

• 한국공작기계학회논문집
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• 제15권3호
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• pp.45-52
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• 2006

Burrs formed during face milling operations can be very difficult to characterize since there exist several parameters which have complex combined effects that affect the cutting process. Many researchers have attempted to predict burr characteristics including burr size and shape, using various experimental parameters such as cutting speed, feed rate, in-plane exit angle, and number of inserts. However, the results of these studies tend to be limited to a specific process parameter range and to certain materials. In this paper, the Taguchi method, a systematic optimization method for design and analysis of experiments, is introduced to acquire optimum cutting conditions for burr minimization. In addition, an in process monitoring scheme using an artificial neural network is presented for the prediction of burr types.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2005년도 춘계학술발표대회
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• pp.225-228
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• 2005

얼굴표정은 상대방에게 자신의 감정과 생각을 간접적으로 나타내는 중요한 의사소통의 표현이 되며 상대방에게 직접적인 표현방법의 수단이 되기도 한다. 이러한 표현 방법은 컴퓨터를 매개체로 하는 메신저간의 의사 전달에 있어서 얼굴표정을 사용함으로써 상대방의 감정을 문자로만 인식하는 것이 아니라 현재 상대방이 느끼는 내적인 감정까지 인식하여 대화할 수 있다. 본 논문은 3D 메시로 구성된 얼굴 모델을 이용하여 사용자가 입력한 한글 메시지의 한글 음절을 분석 추출 하고, 3D 얼굴 메시에 서 8개의 입술 제어점을 사용하여 입 모양의 변화를 보여주는 3D Avatar 아바타 메신저 시스템을 설계 및 구현 하였다.

• Journal of Magnetics
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• 제18권2호
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• pp.117-124
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• 2013

Single-phase, brushless DC (BLDC) motors have unequal air-gaps to eliminate the dead-point where the developed torque is zero. Unfortunately, these unequal air-gaps can deteriorate the motor characteristics in the cogging torque. This paper proposes a novel design for a single-phase BLDC motor with an asymmetric notch to solve this problem. In the design method, the asymmetric notches were placed on the stator pole face, which affects the change in permanent magnet shape or the residual flux density of the permanent magnet. Parametric analysis was performed to determine the optimal size and position of the asymmetric notch to reduce the cogging torque. Finite element analysis (FEA) was used to calculate the cogging torque. A more than 28% lower cogging torque compared to the initial model with no notch was achieved.

• Fibers and Polymers
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• 제3권2호
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• pp.60-67
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• 2002

In the present study, the fluorescence behavior ova phenylethynyl-terminated imide (LaRC PETI-5) resin, a bismaleimide (BMI) resin, and various LaRC PETI-5/BMI blends with different blend compositions has been characterized as a function of heat-treatment temperature, using a steady-state fluorescence technique with a front-face illumination method far solid-state films. It is observed that there are distinguishable changes in the spectral shape, size, and position of fluorescence with varying heat-treatment temperature in the pure and blend samples. The result is qualitatively explained in terms of charge transfer complex formation as well as microenvironmental change with local mobility and viscosity occurring in the LaRC PETI-5, BMI, and their blends during the cure process. The result also implies that a steady-state fluorescence technique may be a useful tool to understand the processing conditions of polyimides and their blends in the film form on the basis of their thermo-photophysical responses.

• 한국공간구조학회논문집
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• 제3권2호
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• pp.101-107
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• 2003

There exists a structural problem for link structures in the unstable state. The primary characteristics of this problem are in the existence of rigid body displacements without strain, and in the possibility of the introduction of prestressing to change an unstable state into a stable state. When we make local linearized incremental equations in order to obtain knowledge about these unstable structures, the determinant of the coefficient matrices is zero, so that we face a numerically unstable situation. This is similar to the situation in the stability problem. To avoid such a difficult situation, in this paper a simple and straightforward method was presented by means of the generalized inverse for the numerical analysis of stability problem.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 E
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• pp.2287-2289
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• 1999

In this paper, a new method for calculating capacitance in multi-electrode system with arbitrarily shape is presented. This new approach based on divergence theorem and Gauss's law is achieved by Surface-Contacted Element(SCE) for Gaussian surface. To evaluate capacitance in multi-electrode system, two dimensional finite element method using only the elements which is contacted one nod (PE: Point-Element) or two nod (FE: Face-Element) with surface is employed. The proposed SCE method has short computing time to calculate capacitance which is because it uses only SCE elements and needs one calculation loop while exiting FEM method in servral loops. This method is verified by application in calculating capacitance using potential detection device model which is composed with anode, cathode, and floating electrode.

• 한국광학회지
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• 제6권4호
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• pp.274-281
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• 1995

본 논문에서는 가상적인 물체를 기록하고 재생하는 새로운 홀로그램 기록방법인 scanned-object holography를 제안하였으며 그 가능성을 이론과 실험을 통해 증명하였다. 이 방법에서는 점광원으로부터 방출되는 구면파의 이동결과와 정지된 기준파를 연속적으로 간섭시킴으로서 점광원의 이동 경로로 표현되는 가상적인 물체를 기록할 수 있었다. 이때 점광원을 실험적으로 구현하기 위해 광섬유 출력단과 펄스형 레이저를 사용하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2006년도 하계종합학술대회
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• pp.259-260
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• 2006

Since audio speech recognition is affected by noise in real environment, visual speech recognition is used to support speech recognition. For the visual speech recognition, this paper suggests the extraction of lip-feature using two types of image segmentation and reduced ASM. Input images are transformed to YCbCr based images and lips are segmented using the contrast of Y/Cb/Cr between lip and face. Subsequently, lip-shape model trained by PCA is placed on segmented lip region and then lip features are extracted using ASM.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1997년도 봄 학술발표회 논문집
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• pp.451-459
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• 1997

Current domestic building market is in the face of a tise in construction cost as a result of labor cost and materials problems, so improvements for productivity are doing their best for finding a way out of the difficulties. But the most of technical of from work is just considered the basic role and shape. As for environment protection, the utilization of waste concrete is important. But many of studies were interesting on the resource recycling for structural concrete. The purpose of this study is the development of thin precast form using recycled aggregate and the assembling systems for permanent form by cast-in-place.