• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
• /
• 제5B권2호
• /
• pp.173-180
• /
• 2005

The construction of a Synchronous Reluctance Motor (SynRM) is simple and also highly economical because a stator from the existing AC motor can be used. Since the synchronous inductance in the Synchronous Reluctance Motor is an element that is proportional to torque, its exact value must be experimentally or analytically found for accurate control and performance development of the motor. In this paper, direct torque control (DTC) simulation is carried out to maximize the torque of the Synchronous Reluctance Motor and the fast response characteristics with the inductance value by the Finite Element Method (FEM). The response characteristics are compared through the proposed direct torque control and torque response characteristics that are based on the existing PI Control in order to confirm the fast response features. To test the performance of the direct torque controller, the torque response is analyzed with variable speed and load condition.

• 제어로봇시스템학회논문지
• /
• 제15권6호
• /
• pp.567-572
• /
• 2009

The underwater launch system using an ATP consists of five parts: compressor tank, proportional flow control servo valve, expulsion spool valve, air turbine pump, and discharge tube. The purpose of this study is to develop an underwater launch system using an ATP and to verify the validity of the system. The proportional flow control servo valve is modeled as a 2nd order transfer function. The projectile is ejected by pressurized water through the air turbine pump, which is controlled by expulsion valve. The mathematical model is derived to estimate the dynamic characteristics of the system, and the important design parameters are derived by using simulations. The computer simulation results show the dynamic characteristics and the possibility of control for underwater launch system.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1996년도 하계학술대회 논문집 A
• /
• pp.528-530
• /
• 1996

Because of the convenience of variable speed control and proportion of input current and torque, DC servo motor has been used as an actuator. With increasing development speed of robot and factory automation machinery, the actuator of excellent control characteristics is demanded. In this paper, The control characteristics of DC servo motor is tested by Fuzzy control with microprocessor and DC servo motor controller is designed for drive of the cartesian coordinate type robot. The control characteristics experimentation is realized to one axis position, two axes coordinate and circular motion control by experimental equipments.

• 한국지열·수열에너지학회논문집
• /
• 제7권1호
• /
• pp.38-44
• /
• 2011

In this study, heating performance and energy consumption characteristics with control strategies for central heating system were researched by the simulation. The simulation analysis is made by TRNSYS ver. 15 with the actual data. The parametric study on proportional factor, control time interval and outdoor air temperatures changes were done to compare control characteristics and energy performance, respectively. As a result, the simulation results with various parameter changes show good heating performance and energy saving.

• 동력기계공학회지
• /
• 제2권2호
• /
• pp.60-66
• /
• 1998

Positioning performance with a normal pneumatic positioning system, is mainly affected by friction force on the actuator and nonlinear characteristics of the control valve. We proposed a positioning system which is composed of a pneumatic actuator and high speed control valve. for accurate and speedy positioning. Driving piston on the actuator is mounted with externally pressurized air bearings to clear the friction force. This paper studies a method in order that improves positioning ability of the pneumatic positioning system considering the nonlinear characteristics of the control valve and the actuator.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 2005년도 추계 학술대회논문집
• /
• pp.125-129
• /
• 2005

Flow control has been performed using synthetic jet on NACA23012. In order to improve aerodynamic performance, synthetic jet is located near separation paint on airfoil with leading edge droop and plain flap. The flow control using synthetic jet shows that stall characteristics and control surface performance can be improved through resizing separation vortices. Stall is delayed and stall characteristics are improved when synthetic jet is applied from separation region of leading edge droop. Control surface effectiveness is increased and lift is increased when synthetic jet applied at the flap leading edge region. The results show that aerodynamic characteristics can be improved through leading edge droop with synthetic jet at near separation and plain flap with synthetic jet at the flap leading edge. The combination of synthetic jet and simple high lift device is as good as fowler flap system.

• 동아시아식생활학회지
• /
• 제10권5호
• /
• pp.403-410
• /
• 2000

In order to investigate the possibility of lwo fat meat products, beef patties were prepared with gums such as carrageenan, methyl cellulose, and xanthangum. The quality characteristics of beef patties were examined. Moisture contents of raw and cooked patties of control were lower than those of patties containing gums, and fat content was higher than those of containing gums. There was no significant difference in the protein contents of patties. In case of L-value(lightness) of raw patty, the control was higher than those patties containing gums. a-(redness) and b-value(yellowness) among patties were not significantly different. Cooking yield, fat retention, and water holding capacity of beef patties containing gums were higher than control beef patty, but salt soluble protein and gel strength were not significantly different. Significant difference did not exist among beef patties in hardness, but the chewiness and gumminess of patties containing gums were higher than control. In case of sensory evaluation, there was no significant difference among patties in aroma and palatability. Texture of control was higher than patties containing gums, and juiciness of control was higher than patties containing carrageenan.

• 한국콘텐츠학회논문지
• /
• 제14권5호
• /
• pp.364-372
• /
• 2014

조직의 성과를 향상시키기 위해 최고경영자의 특성에 맞는 경영통제시스템의 구축이 필요하다. 상황이론에서 경영통제시스템은 다양한 상황변수와의 유기적인 연계를 통해 성과향상을 꾀할 수 있다고 본다. 이에 본 연구는 CEO의 특성변수인 위험감수성향과 성취동기가 행동통제와 결과통제간의 유기적 연결을 통해 재무성과에 미치는 영향에 대해 실증분석을 통해 검증하였다. 본 연구의 결과 위험감수 성향이나 성취동기가 높은 CEO들은 조직구성원들의 구체적인 행동을 통제하므로 써 기업의 재무성과에 더 유의적인 영향을 미친다고 파악되었다. 결과통제는 구성원들의 자율성과 관련된 통제기법으로 기업의 재무적 성과에는 유의적인 영향을 미치지 않는 것으로 나타났다. CEO의 높은 성취동기는 행동통제를 통해 간접적으로 재무성과에 유의적인 영향을 미치는 것으로 나타났다.

• 한국콘텐츠학회논문지
• /
• 제14권7호
• /
• pp.457-467
• /
• 2014

본 연구는 상황분석이론을 적용하여, 최고경영자(CEO)의 특성과 경영통제시스템간의 적합성이 존재할 때 기업의 조직성과에 유의적인 영향을 미치는 가를 구조방정식을 적용하여 실증 분석하고자 하였다. 이를 위해 한국의 제조기업들을 대상으로, CEO의 특성을 크게, 위험감수성향과 성취동기로 구분하였고, 경영통제시스템을 행동통제와 결과통제로 구분하였다. 그리고, 조직성과의 경우, 주로 재무적 특성을 지닌 성과를 적용하여 분석하였다. 각 변수들간의 관계에 대해 개별적 또는 종합적으로 분석하기 위해 구조방정식을 적용하여 분석하였다. 본 연구의 결과, 성취동기와 위험감수성향 중 위험감수성향은 행동통제와 결과 통제에 유의적인 양의 영향을 미치고, 위험감수성향은 행동통제에 음의 영향을 미치는 것으로 나타났다. 위험감수성향에 음의영향과 성취동기에 양의 영향을 받은 행동통제는 조직성과에 유의적인 양의 영향을 미치는 것으로 파악되었다.

• 한국정밀공학회지
• /
• 제18권8호
• /
• pp.116-121
• /
• 2001

The paper presents the dynamic characteristics of a rotor-bearing system supported by an actively controlled hydrodynamic journal bearing. The proportional. derivative and integral controls are adopted for the control algorithm to control the hydrodynamic journal bearing with an axial groove. Also, the cavitation algorithm implementing the Jakobsson-Floberg-Olsson boundary condition is adopted to predict cavitation regions in the fluid film more accurately than conventional analysis, which uses the Reynolds condition. The speed at onset of instability of a rotor-bearing system is increased by both proportional and derivative control of the bearing. The proportional control increases the stability threshold without affecting the whirl ratio. However, for the derivative control of the bearing, increase of stability threshold speed is accompanied by a parallel reduction of the whirl ratio. The integral control has no effect on stability characteristics of hydrodynamic journal bearing. The PD-control is more effective than proportional or derivative control. Results 7how the active control of bearing can be adopted for the stability improvement of a rotor-bearing system.