• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 B
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• pp.804-806
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• 2001

In this paper, by designing ratio width of the permanent magnet versus the stator coil, double excitation LDM with multi-separated winding which is possible to obtain the constant thrust force is proposed. Using Empulse, this paper has explained a various excitation mode to analyze the thrust force of multi-separated winding LDM. The simulation results show single-phase excitation mode have low thrust force ripple.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
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• pp.781-784
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• 2003

In this paper, high density on-board dc/dc converter using multi-layer PCB is proposed. Recently, the communication system wants power supply of open-frame, high density and low profile. So experimental converter was consisted of 3.3V/30A Quarter Brick size DC/DC Converter. To power height limit, coil of transformer, choke and circuits were consisted of multi layer PCB. Besides to improve of efficiency, made secondary synchronous rectifier Mosfet driving circuit. So total efficiency could be improved.

• 전기학회논문지P
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• 제51권1호
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• pp.1-9
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• 2002

This paper describes for new design method to improve respones characteristics of moving-magnet type LDM with volume reduction of slider back iron. To achieve the constant thrust of LDM through restraining saturation at the center core of stator excitation coil, double sided stator winding of LDM is proposed. We constructed new type LDM to prove the validity of design process. Analysis results through measurement and simulation of proposed multi-separated winding LDM were proved excellent in response characteristics and static thrust.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.71-73
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• 2006

AC loss on variation of external magnetic field is a very important factor in development of power applications. In this paper, we measured and compared AC loss of hybrid-multi stacked wire made of the combination of 1G wires and 2G wires and uniform-multi-stacked wire made of one type of wires, 1G wires or 2G wires. Measurement was performed using by the linked-picked coil method. As results, as the number of wires increase, AC loss per unit volume of both stacked wires in low external magnetic field is reduced. Also AC loss of 2G slacked wire is higher than that of 1G wire. AC loss per unit length of 2G stacked wire is less than that of 1G stacked wire. And AC loss of hybrid-multi stacked wire made of the combination of 1G wires and 2G wires was between uniform-multi-stacked wire made of 1G wires and 2G wires.

• 대한의용생체공학회:의공학회지
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• 제17권1호
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• pp.19-24
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• 1996

이 논문의 목적은 Target field approach방법을 사용하여 2차원적인 공간선택을 할 수 있는 고차 평면 경사 자계코일(High-Order SGC: High-Order Surface Gradient Coil)을 설계하는 것이다. 지금까지 쓰이던 원통형의 고차경사자제코일을 이용한 2차원적 원형 선택방법은 한 개의 RF Pulse로 2차원적인 공간 선택을 할 수 있는 장점이 있었으나 선택되어지는 체적의 지름이 6 ~ 8cm로 너무 크다는 단점이 있었다. 이 논문에서는 이와 같은 단점을 극복하기 위해 영상을 얻고자하는 부분에 코일을 좀 더 가까이 붙일 수 있어서 적은 전력으로 선택되어지는 체적의 지름을 1 ~ 4cm까지 줄일 수 있는 표면 고차자계코일을 Target field approach방법을 이용하여 설계하였으며 Phantom과 인체영상을 통해 제작된 코일의 성능을 확인해 보았다. 이전의 Field component 방법을 이용하여 설계한 코일에 의해서 선택되어지는 체적은 타원에 가까운 모양이 되었으나, Target field approach 방법을 이용하여 설계한 코일에 의해서 선택되어지는 체적은 이상적인 원에 가까운 모양이 되었다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.1339-1343
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• 2004

This paper presents a development of the control algorithm and Pick & Placer. The Pick & Placer provides a powerful multi-task system that includes both graphical and remote interface. Users can easily set up sorting parameters and record important data including wafer number, data, and operator information. This System sets up a dustproof device and massively machined components to provide an extremely stable sorting environment. Precise resolution and accuracy result from using machine vision, a pneumatic slide drive and close -looped positioning.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 26-27 Oct. 1990
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• pp.805-810
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• 1990

Optimal control systems for a radial magnetic bearing are proposed and tested. An electromagnet system model is developed to predict bearing forces as functions of changing coil currents and rotor position. Models of the multi-mass rotor supported by the magnetic bearings are developed and confirmed, and theoretical relationships are expressed in the form of state equation. As a result of computer simulation, the state feedback with optimal procedure is considered to be more effective for magnetic bearing systems than the classical method.

• 대한방사선기술학회지:방사선기술과학
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• 제42권1호
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• pp.39-46
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• 2019

This study conducted a comparative analysis of differences between cartesian trajectory in a linear rectangular coordinate system and MultiVane trajectory in a nonlinear rectangular coordinate system axial T1 and axial T2 images using an American College of Radiology(ACR) phantom. The phantom was placed at the center of the head coil and the top-to-bottom and left-to-right levels were adjusted by using a level. The experiment was performed according to the Phantom Test Guidance provided by the ACR, and sagittal localizer images were obtained. As shown in Figure 2, slices # 1 and # 11 were scanned after placing them at the center of a $45^{\circ}$ wedge shape, and a total of 11 slices were obtained. According to the evaluation results, the image intensity uniformity(IIU) was 93.34% for the cartesian trajectory, and 93.19% for the MultiVane trajectory, both of which fall under the normal range in the axial T1 image. The IIU for the cartesian trajectory was 0.15% higher than that for the MultiVane trajectory. In axial T2, the IIU was 96.44% for the cartesian trajectory, and 95.97% for the MultiVane trajectory, which fall under the normal range. The IIU for the cartesian trajectory was by 0.47% higher than that for the MultiVane trajectory. As a result, the cartesian technique was superior to the MultiVane technique in terms of the high-contrast spatial resolution, image intensity uniformity, and low-contrast object detectability.

• 대한의용생체공학회:의공학회지
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• 제22권2호
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• pp.139-144
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• 2001

자기 신경자극기는 신경의학, 재활의학을 포함한 많은 임상의학 분야에서 널리 쓰이고 있다. 자기 신경자극기는 전력소모가 크고 고압 전원이 필요한 이유 때문에 단채널 시스템만이 임상환경이나 연구환경에서 쓰여 왔었다. 본 논문에서는 4채널 자기 신경자극기 개발을 소개하였다. 고압 커패시터를 충전하는데 있어서 단계적 충전방식을 사용하여 작은 크기의 직류 전원장치로 다채널 시스템을 구현하였고, 채널별로 서로 다른 자극 프로토콜로 자극 코일을 구동할 수 있는 다채널 제어시스템을 구성하였다. 개발된 시스템은 신경계통 장애가 있는 환자들의 재활이나 자기적인 침술 등 다양한 기능적 자기 자극에 활용될 수 있을 것으로 기대된다.

• 대한의용생체공학회:의공학회지
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• 제7권1호
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• pp.21-34
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• 1986

In this paper, we described the ECG telemetry system via the Public Telephone Line. The system consist of a signal acquisition and measurement section, a signal processing section, and a signal transmission section. It used 8 bits microprocessor. The transmission section is composed of 3 ch. analog modulators and 1 ct. digital modem. Especially, using the digital modem, signal is transmitted with about 50n data reduction ratio by the TP (Turning Point) algorithm. The acoustic coupler or inductive coil for linking the public telephone line are used. The speed of the digital modem is 300 baud rate. The MCBS (Multi Channel Biotelemetry System) is tested and evaluated through the experiment.