• Proceedings of the KSAR Conference
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• 2003.06a
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• pp.80-80
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• 2003

Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder characterized by motor, cognitive, and psychiatric symptoms, accompanied by marked cell death in the striatum and cortex. Stereotaxic injection of quinolinic acid (QA) into striatum results in a degeneration of GABAergic neurons and exhibits abnormal motor behaviors typical of the illness. The objective of this study was carried out to obtain basic information about whether parthenogenetic mouse embryonic stem (PmES) cells are suitable for cell replacement therapy of HD. To establish PmES cell lines, hybrid F1 (C57BL/6xCBA/N) mouse oocytes were treated with 7% ethanol for 5 min and cytochalasin-B for 4 hr to initiate spontaneous cleavage. Thus established PmES cells were induced to differentiate using bFGF (20ng/ml) followed by selection of neuronal precursor cells for 8 days in N2 medium. After selection, cells were expanded at the presence of bFGF (20 ng/ml) for another 6 days, then a final differentiation step in N2 medium for 7 days. To establish recipient animal models of HD, young adult mice (7 weeks age ICR mice) were lesioned unilaterally with a stereotaxic injection of QA (60 nM) into the striatum and the rotational behavior of the animals was tested using apomorphine (0.1mg/kg, IP) 7 days after the induction of lesion. Animals rotating more than 120 turns per hour were selected and the differentiated PmES cells (1$\times$10$^4$cells/ul) were implanted into striatum. Four weeks after the graft, immunohistochemical studies revealed the presence of cells reactive to anti-NeuN antibody. However, only a slight improvement of motor behavior was observed. By Nissl staining, cell mass resembling tumor was found at the graft site and near cortex which may explain the slight behavioral improvement. Detailed experiment on cell viability, differentiation and migration explanted in vivo is currently being studied.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.852-853
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• 2008

This paper proposes an optimal design method for the shape optimization of the permanent magnets (PM) of an in-wheel permanent magnet synchronous motor (PMSM) to reduce the cogging torque considering a total harmonic distortion (THD) and a root mean square (RMS) value of back-EMF. In this method, the Kriging model based on a design of experiment (DOE) is applied to interpolate the objective function in the spaces of design parameters. The optimal design method for the PM of an in-wheel PMSM has to consider multi-variable and multi-objective functions. The developed design method is applied to the optimization for the PM of an in-wheel PMSM.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.50 no.5
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• pp.214-220
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• 2001

This paper presents the design schemes for the improvement of force characteristics in a controlled permanent magnet liner synchronous motor (Controlled-PM LSM). The dependence of motor performance on the various design schemes, such as the slot shapes, the magnetization patterns of permanent magnet and the skewing, has been investigated in detail by using finite element method (FEM). The analysis results are verified by the experiment that is performed by a testing machine. From this study, it is known that the skewing of the magnet is the most efficient method in the aspects of detent force reduction and higher force density.

• Proceedings of the KIEE Conference
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• 2002.04a
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• pp.31-33
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• 2002

This paper is presents dynamic analysis of slotless PM linear synchronous motor using 3-D analytical method and improvement of controllability using PI control system. In oredr to calculate dynamic characteristic, back-EMF waveform and inductance are caculated by PM's magnetic field and winding's magnetic filed respectively. PMLSM simulated by PI control system.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.04a
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• pp.347-353
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• 2004

Due to various advantages over the conventional linear motion device such as ball-screw, linear motors have been used in wide variety of industrial applications for years. Driven by increased demand for precision machine tools, the importance of high positioning accuracy, high stiffness and high thrust are greatly increasing. The merits of linear motor are high speed high acceleration and good positioning accuracy. In addiction, Linear motor for high qualify machine tool call for high thrust, high stiffness. In this paper, thrust ripple, detent force and thermal behavior are considered for the development of high performance linear motor whose thrust is up to 1,900N. This paper presents a comprehensive study for an iron core type linear motor characteristics that include the influence of PM position on thrust ripple by detent force and motor dynamics as well.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.10a
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• pp.363-368
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• 2004

Due to various advantages over the conventional linear motion device such as ball-screw, linear motors have been used in wide variety of industrial applications for years. Driven by increased demand for precision machine tools, the importance of high positioning accuracy, high stiffness and high thrust are greatly increasing. The merits of linear motor are high speed, high acceleration and good positioning accurcy. In addition, Linear motor for high quality machine tool call for high thrust, high stiffness. In this paper, thrust ripple, detent force and thermal behavior are considered for the development of high performance linear motor whose thrust is up to 10,000N. This paper presents a comprehensive study for an iron core type linear motor characteristics that include the influence of PM position on thrust, thrust ripple by detent force and motor dynamics as well.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.32 no.10
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• pp.850-855
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• 2008

This paper suggests a new linear motor which is able to levitate as well as move its mover without any linear bearing or even additive windings. Its structure is very similar to a well-known both-sided linear motor which consists of two stators and a common mover. And the movement principle is the same with that of conventional linear motor. But unlike the conventional one, the amplitudes of phase currents are controlled to levitate the mover. In this paper, the structure and principle of the suggested bearingless linear motor are introduced in detail and its feasibility is experimentally investigated. Using the prototype and a very simple controller, we succeeded in the levitation and linear movement of the mover at a time.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.48 no.11
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• pp.597-603
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• 1999

Due to its simple construction, operation steadiness and low cost, claw pole step motor is widely used for OA machine and automobile. This paper deals with analysis fo claw pole motor, especially eyeing to dynamic characteristics. To analyze dynamic characteristics of claw pole step motor, torque development in each angular step of rotor are surveyed and torque equation is drived using permeance method. To adopt the airgap MMF, the magnetic equivalent circuit of the motor is introduced. On the base of the magnetic equivalent circuit, the air gap flux equation is derived. To get a optimum design of the motor, the torque characteristic is studied in variation of coil data and remanence value of permanent magnetic material.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.10a
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• pp.423-428
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• 2002

Due to various advantages over the conventional linear motion device such as ball-screw, linear motors have been used in wide variety of industrial applications for years. Driven by increased demand for precision machine tools, the importance of high positioning accuracy, high stiffness and high thrust are greatly increasing. The merits of linear motor are high speed, high acceleration and good positioning accurcy. In addition, Linear motor for high quality machine tool call for high thrust, high stiffness. In this paper, thrust ripple, detent force and thermal behavior are considered for the development of high performance linear motor whose thrust is up to 4,000N. This paper presents a comprehensive study for an iron core type linear motor characteristics that include the influence of PM position on thrust, thrust ripple by detent force and motor dynamics as well.

• 전기의세계
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• v.41 no.8
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• pp.18-21
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• 1992

우리나라 기술측면에서 전기자동차용 전동기를 생각하면 생산기술과 생산설비 등이 갖추어져 있는 유동전동기가 가장 개발하기 쉬울것으로 생각되고 가격면에서도 가장 유리할 것으로 생각된다. 그러나 Bushless전동기의 연구개발은 타 산업에의 파급효과가 클 것으로 예상되고 성능면에서 차후 크게 발전될 것으로 예상되기 때문에 한시도 소홀히 할 수 없는 분야이며 그 외에 switched reluctance motor, PM disk type synchronous motor등의 연구도 함께하여야 할 것이다.