• Proceedings of the KIEE Conference
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• 2004.10a
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• pp.83-85
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• 2004

Recently, a high-speed motor has been generating a lot of attention due to its performance-more light, thin, short, compact than ordinary moters. This paper descirbes the design of the small high-speed BLDC motor with the ratings of 0.5HP and 70 000 rpm for industrial application such as machine tool. Simulation results are given, which show that motor efficiency of higher than 80%.

• Proceedings of the KIEE Conference
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• 2003.04a
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• pp.125-127
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• 2003

Brake forces due to eddy-currents induced by the relative motion of a conductor and a magnetic devices: motors, brakes and magnetically levitated vehicles. In particular, the practicality of using permanent magnet in eddy-current brakes system is obviously recent, due to the manifold improvement in magnet materials and technology. For such a system we give analytical formulas considering eddy-current distribution as variables: flux density for each region and forces.

• Proceedings of the KIEE Conference
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• 2004.04a
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• pp.9-11
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• 2004

In this paper, a new design method to improve efficiency of single-sided linear induction motor(SLIM) is presented. The method utilizes the space harmonic analysis, the equivalent circuit analysis and numerical analysis method. This paper deals with calculation of the design dimension of primary and secondary and the equivalent circuit parameters for SLIM. Finally, analytical results for SLIM designed are verified by FE results.

• Proceedings of the KIEE Conference
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• 2004.04a
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• pp.74-76
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• 2004

This paper deals with the analytical method to calculate the high temperature demagnetization characteristics of a high-speed machine with diametrically magnetized permanent magnet rotor. The equivalent magnetic circuit model is used to analyze the magnet operating point on high temperature condition. Agreements have been obtained between the results of the analytical model and finite-element analysis on prototype high-speed motors.

• Journal of the Mineralogical Society of Korea
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• v.2 no.1
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• pp.11-17
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• 1989

The kaolin deposits in Hadong-Sancheong area, have been formed by supergene weathering of anorthositic rocks including anorthosite, leucogabbro, and gabbro. Kaolin consists chiefly of halloysite(10$\AA$) and kaolinite with other minerals such as illite, vermiculite, plagioclase, hornblende, quartz amorphous materials(allophane and siica), goethite, and hematite. Goethite and hematite are the major coloring agents of the reddish brown and other colored kaolins. Other common accessory minerals are magnetite, ilmentite, anatase, gibbsite, I/S, C/V, chlorite, lithiophorite, and birnessite. Paragonite, dravite, laumontite, clinozoisite, muscovite, scolecite, stellerite are locally found. Al substitution of Fe in goethite and hematite decreases from the surface zone toward the deeper zone. The kaolin deposits show three horizontal zoning; the upper reddish brown, middle pink, and lower white zones. All the zones are characterized by somewhat different mineralogy. The factors for the formation of kaolin deposits in Hadong-Sancheong area are 1) the presence of anorthositic rocks, 2) the low flat or gentle topography, 3) the favorable climate, and 4) the long-continued preservation of kaolins with-out erosion.

• Proceedings of the KIEE Conference
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• 1987.11a
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• pp.203-206
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• 1987

$Ga_{1-x}Al_xAs$ solar cells have been fabricated by LPE and characterized as a function of operating temperature from $25^{\circ}C$ to $l30^{\circ}C$. Open circuit voltage decreases linearly with increasing temperature by $1.4mv/^{\circ}C$, while degradation of silicon solar cells is about $2.2-2.5\;mv/^{\circ}C$. Experimental results regarding to GaAS solar cells, such as saturation current, ideality factors and fill factors are characterized as a function of operating temperature.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.04a
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• pp.128-136
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• 2001

This paper presents an optimum deck and girder system design for minimizing the life-cycle cost (LU) of steel box girder bridges. The problem of optimum LCC design of steel box girder bridges is formulated as that of minimization of the expected total LCC that consists of initial cost, maintenance cost, expected retrofit costs for strength, deflection, and crack. To demonstrate the effect of LCC optimum design of steel box girder bridges, the LCC optimum design is compared with conventional design method for steel box girder bridges design. From the numerical investigations, it may be positively stated that the optimum design of steel box girder bridges based on LCC will lead to more rational, economical and safer design.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.11 no.8
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• pp.1346-1354
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• 2000

본 논문에서는 기존의 루프감지기와 호환성이 있는 레이더 기술을 이용한 차량감지기를 개발하였다. 24 ㎓의 FMCW 고도계와 도플러 속도계 기술을 이용하여 도로상의 차량 길이와 속도정보를 알아낼 수 있는 비매설형의 차량감지기이다. 신호처리에는 DAQ 보드를 사용하였고, 응용소프트웨어인 LabView로 프로그래밍 하였다. 기존의 루프 감지기와 연결된 교통정보 네트웍과의 호환성을 위해 RS-232C 표준인터페이스를 이용하여 VDS(Vehicle Detector System)로 차량데이터를 전송하였다. 속도와 차량길이 정보의 정확도에 있어서 기존 루프감지기보다 약 10% 정도 향상되었음이 측정되었다.

• Proceedings of the KIEE Conference
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• summer
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• pp.1079-1081
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• 2004

Linear induction motors are characterized by a large air gap and, as a result, large leakage inductances. Moreover, due to its unslotted structure and the absence of end rings in the secondary part, the equivalent circuit parameter calculation is very difficult. Therefore this paper introduces the new method of equivalent circuit parameter and analyzes dynamics characteristic of single-sided LIM

• Proceedings of the KIEE Conference
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• summer
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• pp.1343-1345
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• 2004

The inherent pulsating force generation makes the control of switched-reluctance motor quite complicate. So in this paper, an orthogonal scheme that can be applied to the control of LSRM will be presented. By using this scheme, the motor reluctance forces, which are magnetically decoupled and position dependent, can be projected onto sets of stationary axes that are aligned with the motor fixed secondary poles. Hence the electromagnetic forces can be controlled not only for driving the LSRM at its propulsive direction but also for alleviating the load at its normal direction. Simulation results will be provided to show the validity of the proposed scheme.