• Journal of Electrical Engineering and Technology
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• v.11 no.3
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• pp.775-780
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• 2016

This induced voltage measurement test and electromagnetic field simulation are related to the possibility of control signal malfunction by power line. Through an experiment, this research analyzed whether the voltage causing control malfunction according to the on/off status of power permitted to power line was induced to control signal line. Also, the research calculated the voltage induced to control signal line and examined the phenomenon by conducting an electro-magnetic field-specific simulation through the finite element method for the cable model used in the experiment.

• Proceedings of the KIEE Conference
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• 2000.07d
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• pp.2476-2478
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• 2000

Fuzzy Systems which are based on membership functions and rules, can control nonlinear, uncertain, complex systems well. However, Fuzzy logic controller(FLC) has problems: It is some difficult to design the stable FLC for a beginner. Because FLC depends mainly on individual experience. Sliding control is a powerful robust method to control nonlinearities and uncertain parameters systems. But it has a chattering problem by discontinuous control input according to sliding surface. Therfore it needs to be smoothed to achieve an optimal input. In this paper, To solve problems desinged Fuzzy Sliding Control. The effictiveness of result is shown by the simulation and the experimental test for Truck Backer-Upper Control.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.2
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• pp.92-101
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• 2000

The objective of this paper is to design the controller for longitudinal vehicle following which makes the vehicle follow the lead vehicle and keeps a safety distance without human driver operation. This paper presents a sliding mode control algorithm for the ACC system. The controller is based on three sliding surfaces. Each surface plays an individual control-deviation control, throttle control and brake control. In addition to sliding mode control, we propose some additional schemes to enhance controller performance. The first one is a gear shift-down controller which makes tractive force increase with a change of gear ratio. The other is a predictive correction method which reduces slinky effect.

• Journal of Electrical Engineering and Technology
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• v.9 no.2
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• pp.399-405
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• 2014

For stable integration of large-scale wind farms, integration standards (Grid codes) have been proposed by the system operator. In particular, voltage control of large-scale wind farms is gradually becoming important because of the increasing size of individual wind farms. Among the various voltage control methods, Secondary Voltage Control (SVC) is a method that can control the reactive power reserve of a control area uniformly. This paper proposes hybrid SVC when a large-scale wind farm is integrated into the power grid. Using SVC, the burden of a wind turbine converter for generating reactive power can be reduced. To prove the effectiveness of the proposed strategy, a simulation study is carried out for the Jeju system. The proposed strategy can improve the voltage conditions and reactive power reserve with this hybrid SVC.

• Journal of the East Asian Society of Dietary Life
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• v.17 no.1
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• pp.27-42
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• 2007

The purpose of this study is to investigate the importance of well-being related to lifestyle choices such as food habits, food choices, life pattern, etc. The survey was conducted among college students using a questionnaire and a 5-point Likert score in Seoul City and Kyunggido Province during September 2005. The responses of 968 college students were analyzed by the SPSS program. The results were as follows. Most of the subjects were female(76.2%), and lived with their parents (85.6%). The average score of 'food habits', 'choosing food materials', 'purchasing' and 'life pattern' were $2.71{\pm}1.22,\;2.86{\pm}1.28,\;2.41{\pm}1.21,\;and\;2.97{\pm}1.31$ respectively in males and $3.01{\pm}1.20,\;3.00{\pm}1.32,\;2.55{\pm}1.20,and\;2.68{\pm}1.40$ in females, respectively. In regard to 'food habits', the scores were significantly affected by gender(p<0.001), smoking(p<0.05), alcohol consumption(p<0.05), exercise(p<0.001), weight satisfaction(p<0.001), method of weight control(p<0.001), use of nutritional supplement(p<0.05), attempts at weight control(p<0.001), regularity of breakfast(p<0.001), level of interest in well-being(p<0.001), and whether the individual tried a well-being item(p<0.001). In regarding to 'choosing food materials' the scores were significantly affected by gender(p<0.001), smoking(p<0.05), exercise(p<0.001), weight satisfaction(p<0.05), method of weight control(p<0.05), use of nutritional supplement(p<0.05), attempts at weight control(p<0.001), regularity of breakfast(p<0.001), level of interest in well-being(p<0.001) ), and whether the individual tried a well-being item(p<0.001). Out of the factors affecting 'purchasing', the association with BMI was remarkable. Students who were overweight, obese or underweight showed higher average scores than students of normal weight. The primary concerns and trial of well-being of college students were food and exercise. Therefore, the purchase of well-being goods is related to their weight control in college students. In regard to 'life pattern' the scores were significantly affected by exercise(p<0.01), use of computer(p<0.001), BMI(p<0.001), weight control(p<0.001), use of nutritional supplement(p<0.05), regularity of breakfast(p<0.001), level of interest in wellbeing(p<0.001), whether the individual tried a well-being item(p<0.001), and having taken lecture on well-being(p<0.05). Therefore nutrition education is needed for healthy eating habits of college students and it is necessary to develop a series of lectures to teach them about diet and exercise programs.

• Journal of Institute of Control, Robotics and Systems
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• v.12 no.4
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• pp.339-345
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• 2006

An analysis methodology of Decentralized Dynamic Surface Control (DDSC) for the large-scale interconnected nonlinear systems is presented in this paper. While the centralized DSC approach proposed in [14] has a difficulty to check the quadratic stability for the large-scale systems numerically due to dramatic increases of the order of overall augmented error dynamics, DDSC is relatively easy to check the quadratic stability since lower order error dynamics of individual subsystems are used. Then, a systematic procedure for designing DDSC will be developed. Furthermore, after a quadratic function containing a reachable set is defined, it will be calculated numerically to indicate the performance of DDSC in the framework of convex optimization. Finally an illustrative example will be given for showing the advantages of DDSC compared with other decentralized nonlinear control techniques.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.18 no.2
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• pp.152-159
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• 2011

Purpose: This study was done to identify factors related to glycemic control in men with diabetes. Methods: Data from the Korean National Health and Nutrition Examination Survey 2007 2008 collected by the Korean Center for Disease Control were analyzed using chi-square test and t-test. Results: There was a difference in glycemic control according to the individual factor of economic status. Differences in glycemic control according to health related factors were as follows: fasting blood sugar, cholesterol, triglyceride, sleep duration, experience of depression and suicidal thoughts. Conclusion: The results of this study will contribute to improvements in management for men with diabetes through comprehensive identification of factors related to glycemic control.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.11
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• pp.91-100
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• 2007

Many manufacturing devices must execute motions as quickly as possible to achieve profitable high-volume production. Most of them have devices having flexibility and a time delay of one sampling is added to the plants when they are controlled by fast discrete controllers, which brings about non-minimum phase zeros. This paper develops a control strategy that combines feedforward and feedback control with command shaping for such devices. First, the feedback controller is designed to increase damping and eliminate steady-state error. Next, the feedforward controller is designed to speed up the transient response. Finally, an appropriate reference profile is generated using command-shaping techniques to ensure fast point-to-point motions with minimum residual vibration. The particular focus of the paper is to understand the interactions between these individual control components. The resulting control strategy is demonstrated on a model of a high-speed semiconductor manufacturing machine.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.821-825
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• 1991

This paper presents an architecture and control logic of a Flexible Manufacturing Cell (FMC) which is one of the important elements under Computer Integrated Manufacturing (CIM) environment. To implement FMC, it is very important to develop a software which can control and monitor the overall system in an integrated environment. Our primary concern in this research is not to develop individual systems, but to integrate them in the hierarchical control level. Progress on the research of integrating CAD/CAM, Process Planning, Off-line Robot Programming and Simulation module into FMC control system is reported. FMC hardware system used here has an Automated Storage & Retrieval System (AS/RS), a conveyor system, a transfer robot, a CNC milling machine, a bar-code system, and an IBM PC/AT as Cell Control System (CCS). In order to demonstrate the operational result, the name plates, text-carved aluminium plates, are manufactured by this system.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.271-274
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• 2001

The present paper deals with the development of digital contouring controller for multiaxial servosystem. Instead of coordinating the commands to the individual feed drives and implementing closed position loop control for each axis, this work is achieved by the evaluation of a optimal cross-couple compensator aimed specifically at improving contouring accuracy in multi-axial feed drives. The optimal control formulation explicitly includes the contour error in the performance index to be minimized. The contouring control is simulated for straight line. The results show that the proposed controller reduces contouring errors considerably, as compared to the conventional uncoupled control for biaxial systems.