• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 A
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• pp.230-233
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• 1997

In this study, design and analysis of 3-phase induction moter are as follows. - Motor characteristics analysis by equivalent circuit ${\cdot}$ Motor characteristics analysis according to variation of rotor slot-tip ${\cdot}$ Motor characteristics analysis according to variation of rotor slot-mouse ${\cdot}$ Motor characteristics analysis according to variation of rotor slot-opening

• 한국기계가공학회지
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• 제20권7호
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• pp.66-71
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• 2021

In this study, the shape design optimization of a refrigerator door hinge stopper was performed to reduce the discrepancy in the opening forces of the left and right doors of a double-door refrigerator. A finite element model was constructed and analyzed by quasi-static analyses to evaluate the structural performance of the door hinge stopper. The reaction moment calculated at the hinge axis was used as a measure of the door opening and closing forces. The design objective is to increase the door opening force by 50% while maintaining the door closing force and the maximum stress calculated in the body of the hinge stopper at the current level. A new design concept with a contacting slot was proposed to decouple the door closing and opening forces. Shape optimization was performed to determine the dimensions of the new design of the hinge stopper, and the rib pattern was determined by topological optimization to further increase the door opening force. It was observed that the new design met all design requirements.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 A
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• pp.59-61
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• 1995

This paper presents the cogging torque analysis of the permanent magnet type AC servo motor which have the closed slot structure. Generally, existence of the slot opening causes the cogging torque. But the cogging torque exists in this type motor(having closed slot structure) because the bridge part is saturated by the rotor flux. In this paper, the finite element analysis is used to calculate the cogging torque and the rated torque. As the size of the bridge part-the thickness and the width-changes, the cogging torque and the rated torque are obtained repeatedly like as upper procedures. Finally, the trends of the cogging torque and the rated torque versus the size of the bridge part are obtained from this analysis procedures. By this approach, the optimal geometry of the bridge part can be found which minimize the cogging torque satisfying the required value of the rated torque.

• Wind and Structures
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• 제21권3호
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• pp.331-352
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• 2015

A series of wind tunnel tests were conducted on tapered super high-rise buildings with a square cross section by applying synchronous pressure measurement technology. The effects of global strategy of chamfered modification on aerodynamic loads and wind-induced responses were investigated. Moreover, local aerodynamic strategies of opening a ventilation slot in the corner of equipment and refuge floors were carried out. Results show that the global strategy of tapered elevation increased the vortex shedding frequency, but reduced vortex shedding energy, leading to reduction of across-wind aerodynamic loads and responses. Chamfered modification suppressed the across-wind vortex shedding effect on tapered buildings. Opening the ventilation slot further suppressed the strength of vortex shedding and reduced the residual energy related to vortex shedding in aerodynamic loads of chamfered buildings. Finally, the optimized locations of local aerodynamic strategies were suggested.

• 한국농공학회논문집
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• 제54권2호
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• pp.55-65
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• 2012

In the winter season, when the ventilation system is operating, the fresh cold air from the slot-type openings of broiler house which directly reached the animal zone can cause various problems such as thermal stress, decreasing of feed and water consumption, occurrence of respiratory disease, and etc. Therefore it is very important to control the trajectory of aero-flow from the slot openings to induce an efficient thermal heat change. Jet-drop distance model was proposed to predict and control the jet-trajectory. However their study was restricted due to the small scaled model and difficulties of measuring the Jet-drop distance. In this study, CFD was applied to analyze qualitatively and quantitatively the jet-drop distance in a real broiler house. The various variables were considered such as installed slot-angle, designed ventilation rate, and the outdoor ambient temperature. From the present study, two linear-regression models using the Jet-drop factor and corrected Archimedes number, and their R-squared values 0.744 and 0.736, respectively, were used. From this study, the applicability of CFD on the analysis of Jet-drop distance model was confirmed.

• 한국정보통신학회논문지
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• 제10권2호
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• pp.386-391
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• 2006

본 논문에서는 유니 플래너 급전구조를 갖는 V형 선형 테이퍼드 슬롯 안테나를 설계하였다. 설계에 사용한 유전체 기판은 두께가 0.762mm이고 비유전율이 3.0인 PTFE 기판이며 손실 탄젠트는 0.001이다. 또한 중심 주파수는 5.8GHz로 설계하였으며 급전선로의 실현은 Hammerstad에 의한 식을 사용 하였다. V-LTSA의 S11과 VSWR의 시뮬레이션 결과를 얻었으며 -10dB를 기준으로 할 때 대역폭은 약 4.3GHz이었고 VSWR은 약 1.8 Octave의 광대역 특성을 나타내었다.

• 조명전기설비학회논문지
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• 제28권5호
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• pp.39-51
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• 2014

This paper deals with design of a direct-coupled, small-scaled permanent magnet generator (PMG) for wind power application. First, this paper determines rated power and speed of the PMG from measured characteristics of wind turbines. Second, we derive analytical solutions for the open-circuit field in order to determine optimum magnet thickness and pole pitch/arc ratio. Third, on the basis of open circuit field solutions, stator magnetic circuit including slot opening, teeth width and yoke thickness is designed. And then, a diameter of stator coil which agree with a required current density is calculated, and its turns are determined from the area of slot considering winding packing factor. Finally, finite element (FE) method is employed in analyzing the details of the designed PMG and, test results such as back-emf measurements are given to confirm the design.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.395-398
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• 1998

In this paper, the design, fabrication, and experiments of linearly tapered slot antenna(LTSA) with uniplanar microstrip-to-coplanar strip(CPS) line transitions are presented. The effect of reducing and increasing with taper width G teper longth 1, and opening angle are also mesured at 10 GHz.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 춘계학술대회 논문집
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• pp.121-121
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• 2014

본 연구에서는 반도체 제조의 Diffusion 공정설비의 FFU (Fan Filter Unit) 진동에 의해 발생한 wafer 불량 현상을 규명 및 개선하였다. EFEM(Equipment Front End Module)의 Loading 부에 장착된 FOUP(Front Opening Unified Pod)에 들어 있는 Wafer 들이 설비 EFEM 하부로 떨어져 깨지거나 FOUP 내에서 겹침 현상이 발생하는 것을 확인하였다. 이에 생산현장의 모든 Diffusion 공정 설비를 조사하였으며, 그 결과 A 사(社)의 특정 설비에서만 발생되는 현상임을 확인하였다. 해당 A사(社)설비군에서만 월 평균 10 건의 Slot Mapping Error 가 발생하였으며, 이로 인해 Wafer가 재 제조된 매수가 월 평균 53 매로 확인되었다. 따라서 본 연구는 A 사(社)설비에서 발생하는 Mapping Error 의 원인 규명 및 개선을 위해 추진되었다. 총 12 개의 항목을 불량 발생 원인 후보 군으로 선정 후 예비 진단한 결과 FFU(Fan Filter Unit)에 의한 문제 발생 가능성이 가장 높을 것으로 추정되었다. 이에 따라 4 개의 서로 다른 물리적 환경/조건에서 진동을 측정하였으며, 최종 평가 결과 Motor 와 Blade 의 불균형에서 기인한 진동이 설비의 loader 부에 직접적으로 영향을 주는 것을 확인하였다. 진동 문제를 해결하기 위해 고 RPM blade 에서 저 RPM 및 유량 감소를 보완할 수 있는 신규모델로 교체하였다. 신규 Module(blade/motor) 장착 후 Load port 에서의 진동 측정 결과 개선 전 대비 91% 감소하였으며, 결과적으로 Slot mapping error 발생 건수가 50% 이상 감소되는 효과와 Wafer 재 제조 매수도 월 평균 약 43% 감소하는 효과를 얻을 수 있었다.

• Journal of Electrical Engineering and Technology
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• 제10권1호
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• pp.188-194
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• 2015

This paper proposes a generalized regression neural network (GRNN) based algorithm for data interpolation and design optimization of brushless dc (BLDC) motor. The procedure makes use of magnet length, stator slot opening and air gap length as design variables. Cogging torque and average torque are treated as performance indices. The optimal design necessitates mitigating the cogging torque and maximizing the average torque by varying design variables. The data set for interpolation and ensuing design optimisation using GRNN is obtained by modeling a standard BLDC motor using finite element analysis (FEA) tool MagNet 7.1.1. The performance indices of the standard motor obtained using FEA are validated with an experimental model and an analytical method. The optimal design is authenticated using particle swarm optimization (PSO) algorithm and the performance indices of the optimal design obtained using GRNN is validated using FEA. The results indicate the suitability of GRNN as an interpolation and design optimization tool for a BLDC motor.