• Proceedings of the Korean Nuclear Society Conference
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• 1996.11a
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• pp.85-90
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• 1996

In this paper, the self-organizing fuzzy logic controller is developed for water level control of steam generator. In comparison with conventional fuzzy logic controllers, this controller performs control task with no control rules at initial and creates control rules as control behavior goes on, and also modifies its control structure when uncertain disturbance is suspected. Selected parameters in the fuzzy logic controller are updated on-line by the gradient descent loaming algorithm based on the performance cost function. This control algorithm is applied to water level control of steam generator model developed by Lee, et al. The computer simulation results confirm good performance of this control algorithm in all power ranges. This control algorithm can be expected to be used for automatic control of feedwater control system in the nuclear power plant with digital instrumentation and control systems.

• Journal of KSNVE
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• v.8 no.2
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• pp.283-288
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• 1998

If one wants to control the noise from a duct, then one must have sufficient number of sensors and actuators so that the control system is observable and controllable. A number of sensors and actuators for control of radiating noise from a duct have to be incorporated with the number of modes which one wants to control. These considerations motivated the present study that considers a control system which has less microphones and actuators than required. In this work, by theoretical analysis and numerical simulation, the control performance and robust reliability of such a kind of control system is investigated in terms of sound-field variables and control system variables. Then the possibility of implementation of the robust radiation power control system is verified by theoretical analysis and numerical simulation. In addition, the control performance of the control system is verified by experiment.

• Journal of Mechanical Science and Technology
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• v.16 no.9
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• pp.1166-1174
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• 2002

This paper presents the implementation and vehicle tests of a vehicle longitudinal control scheme for Stop and Go cruise control. The control scheme consists of a vehicle-to-vehicle distance control algorithm and throttle/brake control algorithm for acceleration tracking. The desired acceleration of a vehicle for vehicle-to-vehicle distance control has been designed using Linear Quadratic optimal control theory. Performance of the control algorithm has been investigated via vehicle tests. A millimeter wave radar sensor has been used for distance measurement. A stepper motor and an electronic vacuum booster have been used for throttle/brake actuators, respectively. It has been shown that the proposed control algorithm can provide satisfactory performance.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10b
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• pp.135-139
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• 1992

Control of tool-environment interaction force to comply the robot system to an environment is of vital in many automated process. This paper presents the implementation of an adaptive force control with commercial robot system in two dimensional contour following task. A model reference adaptive control system, combined with the linear compensators, is implemented. That is, a use of adaptive control is to provide an auxiliary control system so that the contour following performance can be improved from that of using linear control system only. Hyperstability is used to derive the adaptive control law. Experimental verification of the proposed control system is obtained using PUMA 560 robot system. Data obtained experimentally shows that the use of additional adaptive control system improves the contour following performance about 30% in RMS contact force errors upon that of the system controlled by the linear compensators only.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.1
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• pp.10-14
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• 2004

We present a predictive control algorithm combined with the robust robot control that is constructed on the Lyapunov min-max approach. Since the control design of a real manipulator system may often be made on the basis of the imperfect knowledge about the model, it is an important trend to design a robust control law that guarantees the desired properties of the manipulator under uncertain elements. In the preceding robust control work, we need to tune several control parameters in the admissible set where the desired stability can be achieved. By introducing an optimal predictive control technique in robust control we can find out much more deterministic controller for both the stability and the performance of manipulators. A new class of robust control combined with an optimal predictive control is constructed. We apply it to a simple type of 2-link robot manipulator and show that a desired performance can be achieved through the computer simulation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.10
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• pp.6949-6958
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• 2015

Radio based train control system performs train safe interval control by receiving in realtime the position information of trains driving in the control area of the wayside system and providing onboard system in each train with updated movement authority. The performance of the train control system is evaluated to calculate the minimum operation headway, which reflects the operation characteristics and the characteristics of the train as well as the interval control performance of the train control system. In this paper, we propose the operation headway calculation for radio based train control system and a new train interval control algorithm to improve the operation headway. The proposed headway calculation defines line headway and station headway by the estimation the safety margin distance reflecting the performance of the train control system. Furthermore the proposed Enhanced Train Interval Control(ETIC) algorithm defines a new movement authority including both distance and speed, and improves the train operation headway by using braking distance occurring inevitably in the preceding train. The proposed operation headway calculation is simulated with Korean Radio-based Train Control System(KRTCS) and the simulated result is compared to improved train interval control algorithm. According to the simulated results, the proposed operation headway calculation can be used as performance indicator for radio based train control system, and the improved train control algorithm can improve the line and station headway of the conventional radio based train control system.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.12
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• pp.1027-1033
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• 2020

This study intends to improve job performance during the Covid-19 pandemic at startup companies in Indonesia. In this study, the variables tested were job satisfaction, job innovation, Indonesian culture control, and job performance. Increasing job performance is deemed necessary in facing the economic crisis caused by the Covid-19 pandemic. Job innovation, job satisfaction, and culture control are deemed necessary in improving job performance. The population of this study are managers of start-up companies in Jakarta, Banten, and West Java. This research data obtained by distributing questionnaires to startup managers. This is a quantitative study with primary data. The sample technique used was purposive sampling. Structural Equation Model using Partial Least Square statistical software was used to analyze data. The results of this study indicate a change in the pattern of work performed by startup companies in running their business. Before the Covid-19 pandemic, employees worked in offices for seven hours, but after this pandemic, they change work patterns, moving them to work from home. Working from home requires companies to exercise better control and leadership patterns so that employees can work comfortably.

• Journal of Korean Academy of Nursing
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• v.32 no.6
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• pp.784-791
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• 2002

The anxiety and stress of nursing students on performance intramuscular injection diminished nursing skill performance. The purpose of this study was to identify the effects of the guided imagery program on anxiety, stress and nursing skill performance of nursing students. Method: The study design was time series with a nonequivalent control group pretest- posttest study. The Data were collected from the 30th of Oct. to the 6th of Nov. 2001. The objects of this study were 36 sophomores of university(18 for the experimental group, 18 for the control group). The Instruments used in this study were State Trait Anxiety Inventory developed by Spielberger (1972), Visual Analogue Scale for Stress and Nursing skill performance developed by the researcher. The guided imagery was provided through audiotapes to the subjects for 8 minutes. The pretest was given before the therapy to measure variables for both groups and the posttests were performed after intervention. The data were analyzed by the SAS program using t-test and paired t-test. Result: The results of this study are as follows. The level of anxiety of students who received the guided imagery were significantly lower than that of control group. the level of stress had a deeling tendency and the nursing skill performance level was significantly higher than that of control group. Conclusion: The guided imagery suggested as an effective nursing intervention did reduce the anxiety and promoted nursing skill performance of nursing students.

• Research in Community and Public Health Nursing
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• v.10 no.2
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• pp.307-319
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• 1999

The purpose of this study was to identify the major factors affecting performance in health promoting lifestyle of industrial workers. The subjects for this study 241 workers employed in S company in T city and were obtained by a convenience sample. Data were collected from March 2 to April 28. 1998. The collected data were analyzed using frequency. percent. mean. cronbach alpha. t-test. ANOVA. Person coefficients of correlation. Duncan test. stepwise multiple regression with an SPSS program. The results of this are summarized as follows. 1) The average score of performance in the health promoting lifestyle was 2.62. The variable with the highest degree of performance was harmonious relationship. whereas the one with the lowest degree was professional health maintenance. 2) Performance in the health promoting lifestyle was significantly correlated with self esteem, internal health locus of control and powerful others health locus of control. 3) Performance in the health promoting lifestyle was significantly correlated with such demographic variables as age. religion, education level. marital state. family number. types of dwelling. 4) The most important factor that affect performance in the health promoting lifestyle was powerful others health locus of control and self esteem. On the basis of this study. other factors affecting others health promoting lifestyle should be identified.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.24 no.2
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• pp.128-137
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• 2017

Purpose: This study was conducted to investigate the effects of core basic nursing education using cellular phone video recordings on self-confidence in performance, achievement, and practice satisfaction. Methods: The research design was a nonequivalent control group modified and non-synchronized design. The participants were assigned to either the experimental (n=60) or control group (n=67). During one semester, the experimental group received training for 10 selected core basic nursing skills using cellular phone video recording. The control group, also for one semester, received training with traditional practices. Self-confidence in performance and practice satisfaction were measured using a questionnaire, and achievement was evaluated by professors at the conclusion of the semester. Collected data were analyzed using t-test and Pearson correlation coefficients. Results: Self-confidence in performance increased significantly after training in the experimental group (t=7.94, p<.001). The experimental group showed significantly higher self-confidence in performance (t=2.39, p=.018) and achievement (t=2.40, p=.018) compared to the control group. However, the difference in practice satisfaction was not statistically significant. Conclusion: The results indicate that cellular phone video recording is effective in improving self-confidence in performance and achievement of core basic nursing skills.