• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2001년도 추계학술대회(한국공작기계학회)
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• pp.381-386
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• 2001

When a input image is extensively magnified on the computer system, it is almost impossible to replicate the original shape because of mismatched coordinates system. In order to resolve the problem, the shape of the magnified image has been reconfigured using the bilinear interpolation method, low pass special filtering interpolation method and B-spline interpolation method, Ferguson curve interpolation method based on the CAD/CAM curve interpolation algorithm. The computer simulation main result was that. Nearest neighbor interpolation method is simple in making the interpolation program but it is not capable to distinguish the original shape. Bilinear interpolation method has the merit to make the magnified shape smooth and soft but calculation time is longer than the other method. Low pass spatial filtering method and B-spline interpolation method has an effect to immerge the intense of the magnified shape but it is also difficult to distinguish the original shape. Ferguson curve interpolation method has sharping shape than B-spline interpolation method.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2000년도 전력전자학술대회 논문집
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• pp.709-712
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• 2000

In general three position sensors are needed to drive three phases SRM. Single position sensor driving method for three phases Switched Reluctance Motor(SRM) is proposed in this paper. By using single position sensor the cost of SRM is reduced. But position sensor the cost of SRM is reduced. But position detection at the staring is needed for single position sensor driving method. In this paper we propose the active align method to detect the relative position of rotor to three phases and align to the nearest phase. We proved the validity of the method by experiment and compare with other method.

• 대한전기학회논문지
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• 제39권3호
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• pp.254-262
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• 1990

In the active power filter, the PWM method for controlling the power converter plays an important role for the performance and the efficiency of the filter. In this paper, a new PWM method for the single phase current source type active power filter is presented, which is intended particularly for obtaining the maximum efficiency of the compensation. This method is basically based upon the optimized injection method, but in contrast to the existing method, this method adapts the optimized injection method by putting not only the pulse width, but also the pulse position into control variables. By doing this, when the number of pulses per one cycle is N, lower order harmonics up to the Nth order can be completely eliminated by the filter. So, this method is much more efficient than any other existing method. These characteristics are well verified by the computer simulations and the experiments.

• 한국수학사학회지
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• 제15권3호
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• pp.25-34
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• 2002

This paper explains methods of numerical analysis which appear on Cardano's Ars Magna and Newton's Principia. Cardano's method is secant method, but its actual al]plication is severely limited by technical difficulties. Newton's method is what nowadays called Newton-Raphson's method. But mysteriously, Newton's explanation had been forgotten for two hundred years, until Adams rediscovered it. Newton had even explained finding the root using the second degree Taylor's polynomial, which shows Newton's greatness.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.74-76
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• 2007

A hybrid optimization method is proposed for cogging torque reducing in BLDC motor. The proposed hybrid optimization method comprises a response surface method (RSM) and a gradient search method (GSM). The RSM is effective and global method in optimization problem but having large approximation error. The GSM is accurate and fast search method for optimal solution but having local behavior. To reduce approximation error and computation time a hybrid method (RSM+GSM) is proposed method. To illustrate the effectiveness of the proposed method, a comparison between conventional RSM and the proposed hybrid method is made. A simulation results verify that the hybrid method can achieve favorable design performance.

• 한국정밀공학회지
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• 제21권9호
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• pp.149-157
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• 2004

This paper presents a new method for hi-objective optimization. Ordinary weighted sum method is easy to implement, but it has two significant drawbacks: (1) the solution distribution by the weighted sum method is not uniform, and (2) the method cannot determine any solutions that reside in non-convex regions of a Pareto front. The proposed adaptive weighted sum method does not solve a multiobjective optimization in a predetermined way, but it focuses on the regions that need more refinement by imposing additional inequality constraints. It is demonstrated that the adaptive weighted sum method produces uniformly distributed solutions and finds solutions on non-convex regions. Two numerical examples and a simple structural problem are presented to verify the performance of the proposed method.

• 한국건설관리학회논문집
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• 제5권6호
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• pp.129-137
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• 2004

본 연구는 국내 건설공사의 공기지연 클레임과 관련된 공기지연 분석실태와 해외 건설에서 활용되고 있는 공기지연 분석실태에 대한 문헌고찰을 실시하였다. 국내외 공기지연 클레임 분석방법을 비교하여 볼 경우, 해외에서 일반적으로 쓰여지고 있는 공기지연 분석방법이 국내에서는 적극적으로 활용되고 있지 못함을 파악할 수 있다. 본 연구에서는 국내외 공기지연 분석방법 관련 문헌 및 연구자료를 조사하여 공기지 연 분석방법의 주요개념 및 특성을 정리하였다. 주요한 분석방법으로는 계획대비실적 비교방법, What-if방법, But-for방법, CPA방법, 그리고 DAMUDS방법 등이 있었다. 본 연구에서는 조사된 주요한 공기지연 분석방법들의 적용방법의 특성 및 절차를 명확히 제시하기 위하여, 발생한 공기지연에 대한분석방법의 사례연구를 실시하였다.

• 한국정밀공학회지
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• 제20권7호
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• pp.114-119
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• 2003

The aligning between the punch and die governs no only the burr formation characteristics but also the life time of the punch and die in the sheet metal blanking process. There are many ways to adjust the two elements in the general punching systems but in the case of micro punch system, the punch size is reduced to a few tenth of micrometer range and the general aligning methods are almost impossible to apply. The image processing is the most widely used method in micro punch aligning, but in order to apply the method, it needs quite a large space for visionary system to approach the punch-die aligning zone. In this paper, the new punch-die aligning method with using the total capacitance between the punch and die hole is proposed. In this method, the tip surface of the punch tool locates at the same plane of the die surface and the capacitance variation between the two elements are measured. When the center of the two elements are coincided, the capacitance is minimized, but when the align is changed to any direction, the capacitance between the two elements increase. In order to verify the feasibility of this method, the aligning and punching tests was performed.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 1990년도 추계학술대회논문집; 한양대학교, 서울; 24 Nov. 1990
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• pp.107-112
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• 1990

In the vibration analysis of structure in fluid such as ships and offshore structures, the hydrodynamic added mass considerably affects the result of analysis. Therefore correct evaluation of the hydrodynamic added mass effect is required for an accurate analysis. But the correct evaluation of the effect is not simple because the added mass varies with the mode shape of vibration as well as the configuration of the structure. The universal method employed to evaluate added mass in ship hull vibration is Lewis's method via the introduction of 3 dimensional correction factor. But this conventional method is valid only for beam-like vibration.

• 한국잠사곤충학회지
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• 제13권2호
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• pp.109-117
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• 1971

년간 누에의 다회육을 하는 경우 어떠한 잠종을 어떻게 처리하여서 여기에 응할 수 있겠는가 하는 시험을 6월 상순부터 9월상순까지 매일 매일마다 처리한 잠종에 대하여 조사한 결과 다음과 같은 결과를 얻었다. 1) 6월 상, 중순에 사육한 잠종은 복식냉장법과 단식냉장법과에서 차이가 없었으나, 6월 하순용 잠종은 복식냉장법이 양호하였다. 2) 7월 중순용 잠종은 즉침산냉장법이 양호하였다. 3) 7월 하순용 잠종은 즉침산냉장법이 양호하였으나 단기인공처리법에서는 재검토를 요한다. 4) 8월 하순용 잠종은 단기인공처리법으로서는 더욱 검토하여야 하고 또한 다른 방법을 강구하여야 하겠다. 5) 8월 중순용 잠종은 냉침법이 양호하나, 단기인공처리법도 가능성이 있어 앞으로 검토를 요한다. 6) 9월 상순용은 종래와 같은 냉침법이 양호하고, 또 냉침법은 앞으로 검토를 요한다.