• Journal of Biosystems Engineering
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• 제14권3호
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• pp.168-180
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• 1989

This study was attempted to develop the electronic-hydraulic hitch control system for position control of tractor plow and investigate the control performance of the system through experiments. Experiments were carried out to investigate the responses of the system to the step and sinusoidal inputs in position control. The effects of control mode, hydraulic flow rate, reference deadband, and proportional constant on control performance of the system were investigated. The following conclusions were derived from the study; 1. For the position control system operated on on-off control mode, positions of implement were controlled within ${\pm}0.73^{\circ}{\sim}{\pm}1.46^{\circ}$ in rockshaft angle to the reference position when the hydraulic flow rates were 5~15 l/min. For the position control system operated on PWM control mode, positions of implement were controlled within ${\pm}0.73^{\circ}$ to the reference position regardless of hydraulic flow rates. It means that the implement could be positioned more accurately to the reference position on PWM control mode than on on-off control mode. 2. As results of the frequency responses of the position control systems, no clear difference in control performance between on-off control and PWM control modes was found. As the hydraulic flow rates increased, the corner frequencies of amplitude attenuation and phase-angle change increased. It means that the control performance of the system could be improved as the hydraulic flow rate increases.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2004년도 추계학술대회
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• pp.87-92
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• 2004

This paper presents several control charts for safety and environmental performance monitoring. We also propose guidelines that control charts for statistical process control can be used for safety and environmental performance evaluation.

• 유통과학연구
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• 제22권7호
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• pp.53-61
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• 2024

Purpose: This study aims to analyze distribution of work ethic factors in moderating the influence of Locus of Control on Employee Performance at PDAM (Regional Water Utility) Makassar City. Research design, data and methodology: The sample uses a purposive sampling method with a number sample as many as 35 respondents in PDAM Makassar City. The data collection method used is giving questionnaires to employees in accordance with the research conducted. Data analysis was carried out using multiple linear regression analysis tests and moderated regression analysis with an absolute difference value approach. Results: Locus of control has a positive and significant effect on employee performance and distribution of work ethics are able to moderate the influence of locus of control on employee performance in PDAM Makassar City. Conclusion: when locus of control increases it will be followed by an increase in employee performance, and also equal distribution of work ethic will strengthen the influence of locus of control on employee performance at PDAM Makassar City. Work ethic values that can be implemented include determining work ethic values, clear communication to evaluation and adjustment. The limitation of this research is that it only uses respondents from civil servants and needs further development.

• 기본간호학회지
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• 제23권2호
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• pp.149-160
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• 2016

Purpose: The purpose of this study was to identify factors influencing performance of MultiDrug-Resistant Organisms (MDROs) infection control by nurses in general hospitals. Methods: The research design was a descriptive survey design using convenience sampling. Data were collected from 130 nurses working in 6 general hospitals. Collected data were analyzed using SPSS/WIN 21.0 program for descriptive statistics, t-test, ANOVA, Pearson correlation coefficients and multiple regression analysis. Results: General hospital nurses' MDROs infection control performance was influenced by their awareness of environmental safety, recognition of MDROs infection control, number of beds in the hospital, whether nurses had nursing experience with infection control and guidelines for MDROs infection control. The most important predictors of MDROs infection control performance were awareness of environmental safety and recognition of MDROs infection control. Conclusion: Findings indicate that it is necessary to include content related to awareness of environmental safety and recognition of infection control in developing MDROs infection control education programs for general hospital nurses.

• 전기전자학회논문지
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• 제24권3호
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• pp.877-882
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• 2020

본 논문에서는 계통연계형 인버터(Grid-connected inverter, GCI) 시스템을 위한 전류 제어 방법들의 성능 비교 연구를 제시한다. GCI 시스템을 위해 다양한 전류 제어 방법이 개발되었으며 각 제어기마다 장점과 한계를 가지고 있다. 본 논문에서는 GCI 전류 제어기들의 정상 상태 및 과도 상태에서의 동적 성능을 비교 분석한다. 제안한 전향보상기법(Command feedforward control, CFFC) 및 외란제거제어(Disturbance rejection control, DRC)가 모든 GCI 전류 제어기에 적용 전과 후의 성능을 비교 분석하였다. 제안된 CFFC와 DRC 제어 알고리즘을 주파수 영역에서 분석하고 성능 검증을 위해 각 GCI 전류 제어 방법들의 시뮬레이션 및 실험 모델을 개발하였다.

• Steel and Composite Structures
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• 제51권5호
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• pp.473-485
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• 2024

This paper proposes a composite form of fuzzy adaptive control plan based on a robust observer. The fuzzy 2D control gains are regulated by the parameters in the LMIs. Then, control and learning performance indices with weight matrices are constructed as the cost functions, which allows the regulation of the trade-off between the two performance by setting appropriate weight matrices. The design of 2D control gains is equivalent to the LMIs-constrained multi-objective optimization problem under dual performance indices. By using this proposed smart tracking design via fuzzy nonlinear criterion, the data link can be further extended. To evaluate the performance of the controller, the proposed controller was compared with other control technologies. This ensures the execution of the control program used to track position and trajectory in the presence of great model uncertainty and external disturbances. The performance of monitoring and control is verified by quantitative analysis. The goals of this paper are towards access to adequate, safe and affordable housing and basic services, promotion of inclusive and sustainable urbanization and participation, implementation of sustainable and disaster-resilient buildings, sustainable human settlement planning and manage. Therefore, the goal is believed to achieved in the near future by the ongoing development of AI and control theory.

• 한국간호교육학회지
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• 제23권4호
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• pp.378-388
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• 2017

Purpose: The aim of this study was to identify the status of performance on standard precautions among nursing students and to examine the mediating effects of internal health locus of control on the relationship between awareness and performance on standard precautions of hospital-acquired infection control. Methods: The participants in this study were 134 nursing students. The measurements included a standard precautions awareness and performance scale, and a multidimensional health locus of control scale. Data were analyzed using independent t-test, one-way ANOVA, $Scheff{\acute{e}}$ test, Pearson correlation coefficient, and simple and multiple regression techniques. Mediation analysis was performed by the Baron and Kenny's method and Sobel test. Results: The mean score of standard awareness, standard performance, and internal health locus of control about standard precaution were $174.30{\pm}9.08$; $169.48{\pm}12.04$; and $20.43{\pm}2.82$; respectively. There was a positive correlation between standard awareness and performance (r=.414, p<.001). Also, standard awareness was significantly correlated with internal health locus of control (r=.413, p=.014). Internal health locus of control showed partial mediating effects in the relationship between awareness and performance. Conclusion: The results indicate a need to improve the internal health locus of control of nursing students. Therefore, an internal health locus of control improvement program should improve performance on standard precautions for patients and themselves.

• 한국지진공학회논문집
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• 제9권5호
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• pp.41-52
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• 2005

지진응답제어를 위한 효율적 방법으로 제시된 퍼지관리제어기법은 퍼지에 기반한 의사결정과정을 통하여 가변 제어이득행렬을 구현함으로써 하나의 제어이득만으로 표현되는 선형제어기법보다 개선된 제어성능을 발휘할 수 있다. 이 논문에서는 퍼지관리제어기법의 효율성을 하중 및 교량모델의 불확실성에 대한 제어성능의 강인성 측면에서 평가하였다. 강인성 평가에 있어서는 Dyke등이 제시한 벤치마크 교량에 대하여, 최적설계된 LQG기법과 제어성능을 비교하는 방법을 사용하였다. 불확실성을 주는 요인으로는 주파수 특성이 다른 여러 지진가속도의 규모 및 교량의 강성변화를 가정하였다. 최적설계된 LQG 제어기와 제어효과를 비교한 결과, FSC시스템이 지진의 종류와 규모에 따라 보다 작은 전력을 사용하면서도 개선된 제어성능을 발휘하였다. 특히, LQG 제어시스템이 강성변화에 대하여 불안정한 제어성능을 보인 반면, FSC 시스템은 매우 안정적인 응답제어효과를 보이면서도 제어시스템에 소요되는 전력량과 제어장치의 스트로크에 있어서도 큰 변화를 보이지 않음으로써 매우 탁월한 강인성을 보장할 수 있는 것으로 나타났다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.728-733
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• 2003

In human-mechanical cooperative systems, a significant issue is to improve the control performance and the maneuvering feeling of human operation. However, since it is not easy to evaluate the feeling of operators numerically, control engineers design controllers only through experience. Thus, in this paper, a new evaluation method for control performance of human-mechanical cooperative system is proposed based on the reserge waveform. Various distortions of waveform represent deteriorations of control performance and maneuvering feeling. In some cases, since there is a tradeoff between the control performance and the maneuvering feeling, it is difficult to compensate for both of them by usual feedback controllers. To overcome this situation, the two degrees of freedom control system is applied to human-mechanical cooperative system. Some numerical simulation results for an electric power steering system are shown to confirm the effectiveness of proposed control design method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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• pp.354-356
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• 2006

In this paper, the position control performance of networked control systems is analyzed when time delay through the network is considered. Integrating a control system into a network has great advantages over the traditional control system which uses point to point connection: it allows remarkable reduction in wiring, makes it easy to install and maintain the system, and improves compability. However, a networked control system has the critical defect that network uncertainties, such as time delay, can degrade the control system's performance. Therefore, the major concern of a networked control system is analyzing the effect of network uncertainties. This paper is concerned with PID controller performance for stability region, critical stability region and unstability region under the time delay in the Controller Area Network.