• 전기학회논문지
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• 제56권4호
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• pp.699-704
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• 2007

In this paper, optimized model was designed for the starting characteristic of the Single-Phase Line-Start Permanent Magnet Synchronous Motor by using the Design of Experiment. A field pole angle, thickness and distance from center axis of permanent magnet were selected as design factor. We executed the transient state characteristic analysis of 8 test models. The transient state characteristic analysis was executed by using the 2 dimensional Finite Element Method and the Time Difference Method. We checked the fact that the selected design factor affected starting characteristic of the Line-Start Permanent Magnet Synchronous Motor. Depend on this result we found the optimized design point by using the response optimization.

• 노동경제논집
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• 제38권2호
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• pp.25-58
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• 2015

본 연구에서는 소득과 소비의 불평등을 비교하고, 소득과 소비의 상호 연계에 있어서 항상소득가설의 역할을 분석하였다. 1990년 이후 소득 불평등도는 계속 심화되는 추세를 보였으나, 소비의 불평등도는 2000년대 초반까지 오히려 완화되다가 이후 소득의 불평등도와 동행하는 양상을 보이고 있다. 이는 2000년대 초반 이후 소비에 대한 제약이 충분히 완화되어 우리나라 가구의 소비가 항상소득에 의해 결정되는 양상이 정착되고 있음을 반영하는 것으로 판단된다. 결과적으로 2003년 이후 소비와 소득의 불평등도가 동행하는 양상은 소득의 불평등도 변화에 있어서 항상적 요인의 불평등도가 변동하고 있음을 의미하는 것으로 평가된다.

• 조명전기설비학회논문지
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• 제27권12호
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• pp.125-132
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• 2013

This paper has done a three-dimensional FEM analysis of the PM claw pole stepping motor. As magnetization happens in the z-axis, which does not have a constant value, three-dimensional FEM analysis is necessary for characteristic analysis of PM claw pole stepping motors. Because it is a type of permanent magnet motor, the PM claw pole stepping motor naturally has a detent torque. This torque is known to show negative effects on motor performance. To improve motor performance, reducing the detent torque is very important during the motor design. This paper applied DOE for optimization of stator pole design of the motor. Also, we compared motor performance by applying a different type of rotor shape, dividing the permanent magnet. To verify the simulation results, an experiment was done.

• 한국농촌건축학회논문집
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• 제11권3호
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• pp.37-44
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• 2009

There is a rapid increase of child care centers due to the growth of women's social activities and a nuclear family. Child care center is an important part of community facilities for apartment housing complex. This study aims to collect the basic data required to develop the planning standards for the child care centers. This research limited the child care centers which is situated to permanent rental housing complex. Therefore, this research presents the basic design guidelines for the space composition planning of child care centers by grasping the special quality connected with the space composition of child care centers among the community facilities that is located in the permanent rental apartment housing complex.

• Journal of Power Electronics
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• 제12권4호
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• pp.604-614
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• 2012

This paper presents a comparative study of position sensorless control schemes based on back-electromotive force (back-EMF) estimation in permanent magnet synchronous motors (PMSM). The characteristics of the estimated back-EMF signals are analyzed using various mathematical models of a PMSM. The transfer functions of the estimators, based on the extended EMF model in the rotor reference frame, are derived to show their similarity. They are then used for the analysis of the effects of both the motor parameter variations and the voltage errors due to inverter nonlinearity on the accuracy of the back-EMF estimation. The differences between a phase-locked-loop (PLL) type estimator and a Luenberger observer type estimator, generally used for extracting rotor speed and position information from estimated back-EMF signals, are also examined. An experimental study with a 250-W interior-permanent-magnet machine has been performed to validate the analyses.

• 항공우주시스템공학회지
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• 제7권3호
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• pp.26-32
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• 2013

Passive attitude stabilization method has been widely usde for attitude determination and control of cube satellite due to its advantage of system simplicity. The permanent magnet installed on the cube satellite passively controls the attitude of the satellite such that the satellite is aligned with the earth magnetic field. In this paper, on-orbit thermal behavior of the cube satellite with the permanent magnet attitude stabilization method has been investigated through on-orbit thermal analysis. THe orbit profile obtained from the aforementioned attitude control method has been reflected in the analysis. The analysis results indicate that the thermal design proposed in this study is effective for satisfying the temperature requirements of the commericial mission equipments.

• Journal of Magnetics
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• 제19권4호
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• pp.411-417
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• 2014

This paper presents the shape optimization of a permanent magnet synchronous motor to reduce the torque ripple and iron loss. Specifically, the harmonics of the electromotive force and cogging torque are decreased by adjusting the permanent magnet arrangement and non-uniform air gap length. In addition, an additional flux path along the q-axis is proposed with a unique rotor shape to increase the q-axis inductance and reluctance torque. The improvement in the performance of the proposed model is verified with simulated and experimental results.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 봄 학술발표회 논문집(I)
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• pp.475-480
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• 1999

Recently domestic building market in the face of 3D, in addition to construction cost increase, materials lack problems and opening a building market to foreign countries, is trying to find out the efficient ways of overcoming these problems. So the necessity to study the permanent form is urgent to escape the problems of constructing human power economy, cost down, noises problem, environmental prevention and efficacy of form work to technical improvement will contribute a practical permanent form in field through economic evaluation of permanent form. In this paper, we compared wood form cost with permanent form cost(made form polymer or fly ash) for frame work

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2004년도 춘계학술발표회
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• pp.189-196
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• 2004

In this study, the colloidal silica grouts (PSG) with novel chemical compositions for permanent reinforcement and water cut-off of the ground were prepared and their engineering charateristics were investigated. The optimum mixing recipes for both homogeneous solution grouts and heterogeneous suspension grouts were investigated and established through many repeated lab tests. The various physical properties(such as compressive strength, durability and syneresis) of the grout gels derived from the colloidal silica were investigated and compared with those of the well-known existing watergalss grouts. The all experimental results showed that the novel colloidal silica grouts(PSG) had greatly excellent performances as permanent grouts, especially in comparison with the existing watergalss grouts.

• 대한소아치과학회지
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• 제24권3호
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• pp.562-567
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• 1997

During the eruption of permanent teeth, Traumatic root fractures in young permanent incisors are rare. They occur most commonly in the maxillary central incisors of male patient and are frequently seen in the coronal third of the root. Permanent incisors are very important in terms of esthetics as well as of function, and so conservative treatment is advisable. It is important to maintain vitality of pulp to achieve better result. Location of the fracture line determines the Prognosis. No clinical change were seen in this three case. A case of central incisor with apparent healing of a root fracture without any tratment is presented in this paper. Long term clinical observation is required periodically.