• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.41.1-41
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• 2001

Since the advanced control technique such as model predictive control has been introduced to industrial plant, there have been many progresses in the process control. As a way to improve the control performance, the on-line process optimizer was integrated with the advance controller. In this study, a control technique which improves the control. As the number of changes by the optimizer is increased, the control performance of the proposed algorithm is improved. Its control performance is shown via an numerical example.

• Journal of Institute of Control, Robotics and Systems
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• v.5 no.2
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• pp.123-130
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• 1999

In discrete-time controlled system, sampling time is one of the critical parameters for control performance. It is useful to employ different sampling rates into the system considering the feasibility of measuring system or actuating system. The systems with the different sampling rates in their input and output channels are named multirate system. Even though the original continuous-time system is time-invariant, it is realized as time-varying state equation depending on multirate sampling mechanism. By means of the augmentation of the inputs and the outputs over one period, the time-varying system equation can be constructed into the time-invariant equation. The two multirate formulations have some trade-offs in the simplicity to construct the controller, the control performance. It is good issue to determine the suitable formulation in consideration of performance of them. In this paper, the two categories of multirate formulations will be compared in terms of the linear quadratic (LQ) cost function. The results are used to select the multirate formulation and the sampling rates suitable to the desired control performance.

• 제어로봇시스템학회:학술대회논문집
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• 1994.10a
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• pp.283-288
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• 1994

The adaptive control and the robust control have been considered as the most influential methods for robotic motion control. The purpose of this paper is to compare control performance between these two strategies in unconstrained motion control of robot manipulator. In order to compare control performance properly, intensive experiments are required and only then can conclusions be drawn on the relative merit and demerit of the controllers. Firstly, the control algorithms for unconstrained motion control are summarized. In adaptive control, the controllers that have been proposed so far are classified according to the signals used for the computed control input. It enables rather easier to compare controller is examined to demonstrate control performance of robust controllers. Finally, the above two approaches, the adaptive and the robust are compared from the view-point of robustness to plant uncertainty, which is one of the most demanding properties in robot motion control.

• The Korean Journal of Health Service Management
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• v.7 no.4
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• pp.131-141
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• 2013

The purpose of this study was to investigate the long-term care hospital nurse's recognition and performance level of hospital infection control. The subjects of the study were 147 long-term care hospital nurses. The period of data collection was from April 1 to 30, 2013. The data were analyzed by SPSS 19.0 program. The result are as followed; First, the total average scores of the recognition and performance by long-term care hospital nurses of hospital infection control were $4.64{\pm}0.32$ and $4.21{\pm}0.23$. Second, recognition of hospital infection control was significantly different according to position and hospital infection control education experience. Performance of hospital infection control was significantly different according to education level and hospital infection control education experience. Third, there was a positive correlation between the degree of recognition and performance of hospital infection control. Therefore, it is suggested to apply the concrete education program to enhance the recognition in order to improve the performance of hospital infection control of the Long-term hospital nurses.

• Journal of Korean Public Health Nursing
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• v.35 no.2
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• pp.297-309
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• 2021

Purpose: This study aimed to identify factors relating to COVID-19 knowledge and resilience that impact elementary school health teacher performance at infection control. Methods: This study adopted a cross-sectional design. Data were collected from 140 elementary school health teachers by convenience sampling. Collected data were analyzed using SPSS Ver. 26.0. Results: Mean scores were as follows COVID-19 knowledge 17.99±2.37 (range 0-23), resilience 120.36±16.90 (range 30-150), and performance at infection control 85.91±10.07 (range 25-100). A positive correlation was observed between resilience and infection control performance (r=0.57, p<.001). Factors found to influence participant performance at infection control were resilience (𝛽=0.54, p<.001) and two categories of educational experience: 11-15 years (𝛽 = 0.24, p=.011) and more than 20 years (𝛽=0.29, p=.044). Conclusion: These results indicate the resilience of elementary school health teachers positively affects their performance at infection control. Generally, both age and work experience affected ability to perform infection control. Therefore, this study supports the need to develop programs to increase the resilience of elementary school health teachers according to infection control performance and age.

• Journal of Korea Trade
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• v.23 no.7
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• pp.128-146
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• 2019

Purpose - The purpose of this paper is to investigate the relationship between internal control, economic policy uncertainty, and performance of cross-border merger and acquisition (M&A) based on the panel data of Chinese listed firms. The authors expected that internal control has a positive moderating effect on the performance of cross-border M&A and that it mainly occurs during periods when economic policies are relatively stable. In addition, the authors tried to find out the mechanism of internal control affecting cross-border M&A and the corporate performance. Design/methodology - The authors tested the hypotheses by a multivariate regression model based on the panel data of Chinese listed firms from 2009 to 2017. The dependent variable is the change value of business performance (DROA_1,2,3) and the explanatory variables are cross-border M&A (MA), China's uncertainty of economic policy (EPU), and internal control level (IC) respectively. Findings - The authors find that internal control has a positive moderating effect on the relationship between cross-border M&A and corporate performance. Further, the authors find that the moderating effect is more significant in state-owned enterprises and that it mainly occurs during periods when economic policies are relatively stable. Originality/value - This paper is the leading study that tries to analyze empirically the relationship between internal control, economic policy uncertainty, and performance of cross-border M&A. It provides a new avenue through which internal control might reasonably mitigate the risks of cross-border M&A and correspondingly improve the performance of cross-border M&A. It also confirms the moderating effect of internal control on the performance of cross-border M&A under the uncertainty of economic policy.

• Journal of radiological science and technology
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• v.45 no.3
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• pp.263-272
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• 2022

This study investigated small and medium-sized hospital workers' knowledge of COVID-19, the infection-control-related fatigue and stress levels, and the factors that impacted their performance during the COVID-19 pandemic. Using a cross-sectional design, data were collected from 137 hospital workers from four small and medium-sized hospitals in S and C cities. Data were analyzed using descriptive statistics, a t-test, analysis of variance(ANOVA), Pearson's correlation coefficient, and multiple linear regression analysis. Small and medium-sized hospital workers' knowledge of COVID-19 revealed a correct answer rate of 66%. An average of 3.00 points out of 4 for infection control performance and 3.32 and 3.17 points out of 5 for infection-control-related fatigue and stress, respectively, were found. The level of knowledge regarding COVID-19 significantly differed by age and marriage (p<0.05), while infection control performance significantly differed by age, marriage, and infection control education experience (p<0.05). Infection-control-related fatigue and stress differed depending on the COVID-19 control education experience, economic and social prejudice, and fear of discrimination. There were positive correlations between knowledge and infection control performance, and infection control performance and infection-control-related fatigue and stress (p<0.001). This study showed that the factors that affected small and medium-sized hospital workers' performance included knowledge of "environmental management," "difficulties due to new role requirements," "presence or absence of infection education experience," "job type," and "age." These results suggest that practical and detailed education programs should be systematically developed and implemented for effective infection control.

• Smart Structures and Systems
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• v.16 no.6
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• pp.1147-1167
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• 2015

Wireless smart sensors, which have become popular for monitoring applications, are an attractive option for implementing structural control systems, due to their onboard sensing, processing, and communication capabilities. However, wireless smart sensors pose inherent challenges for control, including delays from communication, acquisition hardware, and processing time. Previous research in wireless control, which focused on semi-active systems, has found that sampling rate along with time delays can significantly impact control performance. However, because semi-active systems are guaranteed stable, these issues are typically neglected in the control design. This work achieves active control with smart sensors in an experimental setting. Because active systems are not inherently stable, all the elements of the control loop must be addressed, including data acquisition hardware, processing performance, and control design at slow sampling rates. The sensing hardware is shown to have a significant impact on the control design and performance. Ultimately, the smart sensor active control system achieves comparable performance to the traditional tethered system.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.107-112
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• 2005

When it comes to automatic operation control of urban rail vehicle, a PID control makes it run between stations within the fixed time and stop exactly at the stop sign on the platform, satisfying jerk limit. An optimal control is applied to automatic operation performance control to minimize energy consumption while the urban rail vehicle satisfies automatic operation condition on this paper. The control performance in terms of energy minimization along with the constraint on precision stops is compared between the optimal control and PID control.

• Journal of Institute of Control, Robotics and Systems
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• v.10 no.6
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• pp.510-518
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• 2004

The PID trajectory tracking controller for robotic systems shows performance limitation imposed by inverse dynamics according to desired trajectory. Since the equilibrium point can not be defined for the control system involving performance limitation, we define newly the quasi-equilibrium region as an alternative for equilibrium point. This analysis result of performance limitation can guide us the auto-tuning method for PID controller. Also, the quasi-equilibrium region is used as the target performance of auto-tuning PID trajectory tracking controller. The auto-tuning law is derived from the direct adaptive control scheme, based on the extended disturbance input-to-state stability and the characteristics of performance limitation. Finally, experimental results show that the target performance can be achieved by the proposed automatic tuning method.