• Clinical and Experimental Pediatrics
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• 제49권4호
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• pp.375-380
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• 2006

목 적 : 엎어 재우기, 똑바로 누워 재우기, 옆으로 재우기 등 수면 자세에 따라서 조대운동발달과 미세운동발달이 차이가 나는지 살펴보기 위해서 연구를 시작하였다. 방 법 : 2003월 12월부터 2005년 9월까지 1년 9개월 동안, 전주예수병원 소아과를 방문하는 3개월부터 16개월 사이의 소아 800명을 대상으로 운동발달검사, 수면 자세, 몸무게를 조사하여 연구하였다. 결 과 : 똑바로 누워 재우기가 79.3%, 엎어 재우기가 10.0%, 옆으로 재우기가 10.7%로, 똑바로 누워 재우기가 가장 많았다. 남아와 여아의 조대운동발달 지수는 각각 $109.5{\pm}16.3$, $108.1{\pm}17.3$이었으며, 미세운동발달 지수는 각각 $102.3{\pm}17.1$, $100.7{\pm}16.9$로 성별에 따른 발달의 차이는 없었다. 똑바로 누워 재우기, 엎어 재우기, 옆으로 재우기에 따른 조대운동발달 지수는 5개월에 $98.2{\pm}16.8$, $126.2{\pm}10.9$, $117.2{\pm}6.6$, 6개월에 $101.2{\pm}13.0$, $115.2{\pm}18.0$, $95.7{\pm}20.2$로 각각 엎어 재우기에서 의의 있게 높았다. 7개월에서 16개월까지는 차이가 없었다. 똑바로 누워 재우기, 엎어 재우기, 옆으로 재우기에 따른 미세운동발달 지수는 차이가 없었다. 연령별 평균 미만의 몸무게 군과 연령별 평균 이상의 몸무게 군에서, 조대운동발달 지수는 각각 $106.3{\pm}16.3$, $109.9{\pm}16.8$이고, 미세운동발달 지수는 각각 $99.4{\pm}16.2$, $102.5{\pm}17.2$로 연령별 평균 이상의 몸무게 군에서 조대운동발달 지수와 운동발달 지수가 의의 있게 높았다. 결 론 : 엎어 재웠을 경우 5개월과 6개월에서 조대운동발달 지수가 높았으나, 7개월부터는 차이가 없었다. 따라서 운동발달을 빠르게 하기 위해서 엎어 재우는 것은 의미가 없는 것으로 판단된다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2000년도 전력전자학술대회 논문집
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• pp.605-609
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• 2000

This paper presents a development of the Pulse Width Modulation ASIC for control of the AC servo or spindle motor in machine tools. The ASIC is designed two PWM functions for simultaneous control of a converter and an inverter. Also the device includes additionally two UART functions for interfacing the RS232C with PC or other devices. The device is connected to the microprocessor of Intel or Motorola by bus interface. The required output voltage and frequency for the motor control is programmed to the PWM block and the corresponding switching signals are calculated and generated with regard to the programmed value.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 춘계학술대회 논문집
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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.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 추계학술대회 논문집 학회본부
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• pp.24-26
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• 1995

The Development of A.C. Induction Motor for Railway Rolling Stock. The traction motor is designed as 4-pole induction motor with self ventilation. The winding insulation is throughout of materials of class C. The rotor is designed as a squrrel rotor with copper bar and casting. The rotor speed is detected by means of a pulse generator. The newer tection motor have no casting(frame). Punched-in holes make up the air duct and transfer the heat losses in complete. Maximim motor rpm is higher due to rotor construction. New is the entry of water-cooled traction motors in urban, However the water cooling design in - unfortunately - not applicable in traction motor.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2004년도 추계학술대회 논문집
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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.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 춘계학술대회논문집
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• pp.709-712
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• 2003

Recently, high noise problem was experienced during the development of 2-pole squirrel cage motor for industrial compressor. In order to firstly identify the noise characteristics, a variety of measurements were carried out. It was found out that high noise was dominated by linear and nonlinear slot noise components. For the development of low noise indusrial motor, the air gap between rotor and stator in the motor was firstly enlarged. Secondly, it was also modified for the cooling housing to have high absorption features. Consequencely, low noise 2-pole motor having the noise level of less 80㏈(A) was developed. In this paper, a series of noise identification and control process for this motor are introduced.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 추계학술대회 논문집
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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.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 B
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• pp.779-781
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• 2004

Recently, as the interests in the electrical propulsion ship increase, it is needed to prepare for the technical demand of the versatile HTS synchronous motor, the noble paradigm of the electrical motor. In this paper, the electrical propulsion apparatus was classified at first. The, the merits and demerits of the HTS synchronous motor were investigated. Finally, the feasibility study of development of the HTS motor was performed with electromagnetic FEM analysis. Additionally, the points to be considered in decision of the capacity or number of the HTS motor and the way to supply electricity were studied in this paper. This work would be very useful in establishing the development direction of the HTS motor

• 한국정밀공학회지
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• 제27권6호
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• pp.39-46
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• 2010

Linear induction motor is adopted as an actuator of the planar stage. An inherently poor characteristic at zero or ultra-low speed zone of the induction motor is remarkably improved due to a recent development of power electronic semiconductor technology and a spatial vector control theory. At present, a servo response speed of the induction motor reaches 90 percent of one of PM synchronous or BLDC motor. Specially, as a secondary of the induction motor can be constructed using uniform conducting sheets, there is no periodic force ripple as in PM motors. So, the induction motor can be superior to another driving means under a certain condition. This paper discusses the overall development procedure of non-contact planar stage with a big workspace using linear induction motors.

• 한국수소및신에너지학회논문집
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• 제25권5호
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• pp.516-524
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• 2014

Proper discharge of nitrogen gas and water condensate is required in a conventional fuel cell system for performance, stability and durability of fuel cell stacks. Present study covers the development of integrated unit and its functioning logic for simultaneous nitrogen gas purge and water condensate drainage in a fuel cell vehicle system. Configuration of condensate drainage pipe, purge valve and level sensor is considered and optimized in physical integration. As a key factor, discharge time is considered and optimized based on the test result of constant-current operation with various operating temperature in logic development. Consequently, derived optimal values are applied and verified in actual vehicle drive mode test. Increase of system design flexibility, weight reduction and cost reduction are anticipated with this study. Additional study for physical and logical improvement is currently being implemented.