• Transactions of the KSME C: Technology and Education
• /
• v.4 no.1
• /
• pp.35-41
• /
• 2016

Geothermal heat pump (GHP) systems have been proved to be one of the most efficient systems for heating and cooling in buildings. However, an optimal energy performance depends on a good control of the system components, including heat pumps and circulation pumps, which affect to the total energy consumption of system. This paper presents the simulation results of the heat pump performance for two different control schemes, i.e. constant setting temperature (Control-A) and variable setting temperatures (Control-B) in buffer tank. A dynamic simulation tool, TRNSYS 17, was used to model the entire system and to assess the performance of the system. Simulation results show that the Control-B, which controls the temperature in buffer tank with outdoor air temperature, is a effective way to reduce the energy consumptions in heat pump (7.7%) and circulation pump (7.5%).

• Earthquakes and Structures
• /
• v.15 no.6
• /
• pp.595-603
• /
• 2018

Shake table testing has been regarded as one of the most effective experimental approaches to evaluate seismic response of structural systems subjected to earthquakes. However, reproducing a prescribed acceleration time history precisely over the frequency of interest is challenging because shake table test systems are eventually nonlinear by nature. In addition, interaction between the table and specimen could affect the control accuracy of shake table testing significantly. Various novel control algorithms have been proposed to improve the control accuracy of shake table testing; however, reference values for control performance assessment remain rare. In this study, reference values for control performance assessment of shake table testing are specified based on the statistical analyses of 1,209 experimental data provided by the Seismic Simulator Laboratory of National Center for Research on Earthquake Engineering in Taiwan. Three individual reference values are considered for the assessment including the root-mean-square error of the achieved acceleration time history; the percentage of the spectral acceleration that exceeds the determined tolerance range over the frequency of interest; and the error-ratio of the achieved peak ground acceleration. Quartiles of the real experimental data in terms of the three objective variables are obtained, providing users with solid and simple references to evaluate the control performance of shake table testing. Finally, a set of experimental data of a newly developed control framework implementation for uni-axial shake tables are used as an application example to demonstrate the significant improvement of control accuracy according to the reference values provided in this study.

• Animal Bioscience
• /
• v.34 no.2
• /
• pp.256-264
• /
• 2021

Objective: The purpose of this experiment was to investigate the effects of the Agaricus bisporus stem residue (ABSR) on the performance, nutrients digestibility, antioxidant activity of laying hens, and its effects on egg storage to determine the appropriate dosage of ABSR, so as to provide a scientific basis for the effective utilization of ABSR. Methods: A total of 384 53-wk-old Nongda III layers were randomly divided into six treatments, four replicates in each treatment and 16 birds in each replicate. The control treatment was fed with basic diet, while experimental treatments were fed with diets of 2%, 4%, 6%, 8%, and 10% ABSR respectively. The experimental period was 56 d. Results: The results showed that compared with the control treatment, ABSR had no significant effect on laying performance (p>0.05). The crude protein and total energy digestibility of experimental treatments was significantly higher than those of control treatment (p<0.05). When eggs were stored for 1 wk, 2 wk, and 3 wk at 25℃, there were no significant differences in egg storage between the experimental treatments and the control treatment (p>0.05). The superoxide dismutase (SOD) activity and glutathione peroxidase (GSH-Px) activity in the serum of the experimental treatments were significantly higher than those of the control treatment (p<0.05), and the malonaldehyde (MDA) content did not change dramatically. SOD activity in yolk of experimental treatments was significantly higher than that in control treatment (p<0.05); MDA content in yolk was markedly lower than that in control treatment (p<0.05). The activity of GSH-Px and SOD in yolk of experimental treatments was significantly higher than that of control treatment stored at 25℃ for 21 d, and the content of MDA was significantly lower than that of control treatment (p<0.05). Conclusion: ABSR can be used to improve the antioxidant activity of laying hens without affecting laying performance.

• Journal of the Korea Convergence Society
• /
• v.12 no.11
• /
• pp.155-160
• /
• 2021

This study analyzed the awareness and performance of physical therapists' infection control using IPA. The four areas were divided into handwashing, personal management, Treatment room environment management, and infection control education, and a survey was conducted on awareness and practice. General characteristics were analyzed for frequency, and recognition and performance were analyzed through paired t-test and Pearson's correlation. Handwashing was both high and infection, control education had high performance, but low awareness. The performance of Treatment room environment was high, but the awareness was low, and personal management was both low. Therefore, based on this study, there is a need for a strategy to improve the awareness of infection control education, a strategy to improve performance in the treatment room environment, and a strategy to improve both performance and awareness in Personal management.

• International Journal of Aeronautical and Space Sciences
• /
• v.17 no.3
• /
• pp.442-453
• /
• 2016

A significant source of vibration in helicopters is the main rotor system, and it is a technical challenge to reduce the vibration in order to ensure the comfort of crew and passengers. Several types of passive devices have been applied to conventional helicopters in order to reduce the vibration. In recent years, helicopter manufacturers have increasingly adopted active vibration control systems (AVCSs) due to their superior performance with lower weight compared with passive devices. AVCSs can also maintain their performance over aircraft configuration and flight condition changes. As part of the development of AVCS software for light civil helicopter (LCH) applications, a test bench is constructed and vibration control tests and simulations are performed in this study. The test bench, which represents the airframe, is excited using a pair of counter rotating force generators (CRFGs) and a multiple input single output (MISO) AVCS that consists of three accelerometer sensors and a pair of CRFGs; a filtered-x least mean square (LMS) algorithm is applied for the vibration reduction. First, the vibration control tests are performed with uniform sensor weights; then, the change in the control performance according to changes in the sensor weight is investigated and compared with the simulation results. It is found that the vibration control performance can be tuned through adjusting the weights of the three sensors, even if only one actuator is used.

• The Journal of the Korea Contents Association
• /
• v.13 no.5
• /
• pp.377-386
• /
• 2013

The purposes of this study is to examine the effect of fitness Among Characteristics of CEO, Company's innovation and Management Control on Organization Performance. CEO characteristics are investigated by the risk-taking propensity, need for achievement. Company's Innovation are measured by product innovation, technological innovation. Management control are applied by action control and result control. Organization performances are analyzed by internal performance, growth performance, financial performance. the research methodology applied in this paper is contingency theory by Drazin and Van de Ven(1985) - selective approach, Interaction approach, system approach. This paper was applied by the Three way interaction term among CEO characteristics, Company's Innovation and Management control to analyze the influences to the organization performances. As a result of this paper, there are the differences between Two way interaction terms or three way interaction terms to affect the organization performances. this paper can confirm the desirable combinations between two or three variables(CEO characteristics, Company's Innovation and Management control) to affect significantly to the particular organization performance.

• The Journal of the Korea Contents Association
• /
• v.15 no.6
• /
• pp.346-357
• /
• 2015

Purpose: This descriptive study was to examine uncertainty and performance of infection control in the VRE patients' caregivers. Methods: The participants were 82 caregivers who involved with the VRE patients care in D tertiary hospital in D metropolitan city. Data were analyzed with number, percentage, t-test, and ANOVA using SPSS/Win 21.0. Results: The participants' uncertainty was 56.99 and performance of infection control was 35.09. Performance of infection control was significantly different by age (F=121.38, p<.001), education (F=102.77, p<.001), relationship with the patient (F=17.80, p<.001), hours of caring per day (t=3.14, p=.002), and type of family (t=-8.65, p<.001). There was a significant negative correlation between participants' uncertainty and performance of infection control (r=-.96, p<.001). Conclusion: The results of the study will be used to develop nursing intervention program and standard protocol for infection control for the VRE patients' caregivers.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.33 no.8
• /
• pp.50-55
• /
• 2005

An advanced method of Relaxed Static Stability (RSS) is utilized for improving the aerodynamic performance of modern version supersonic jet fighter aircraft. The laws of flight control system utilize RSS criteria in both longitudinal and lateral-directional axes to achieve performance enhancements. Particularly, the design of longitudinal control laws for utilizing RSS methods greatly affects the performance of the aircraft in Air-to-Air Tracking and Air-to-Ground modes, which improves weapon delivery. In the area of Air-to-Air Tracking, the development of longitudinal control laws aids in the fine tracking and gross acquisition of other aircraft. This paper proposes that new concept of longitudinal control law introduce in order to improve fine tracking performance in air-to-air tracking maneuver. Result of HQS pilot simulation and flight test, fine tracking performance improve without degradation of gross acquisition when new concept of control law is applied.

• Proceedings of the KIEE Conference
• /
• 2006.10c
• /
• pp.318-320
• /
• 2006

A control valve with deadband characteristics influences on the control dynamics. A control loop with deadband component shows cyclic control results and causes the wears of mechanical parts. A valve on the important process that require nonstop operation cannot be improved during operation. In case of control loops with deadband dynamics, the optimal control parameters based on the performance only are not sure of the good operation in point of protecting the control component. To improve the control performance and control oscillation, the control parameters should be changed to meet both control qualify and protection of control components.

• Journal of Environmental Science International
• /
• v.27 no.10
• /
• pp.933-936
• /
• 2018

An experiment was conducted to evaluate the efficacy of a mixture of bentonite and illite as feed additives on the growth performance and litter quality of 90 Pekin ducks. The ducks were individually weighed and randomly divided into two treatments (control and 1% combination of silicate minerals), with three replicate pens per treatment, and 15 ducks per pen. Growth performance was not significantly affected (p>0.05) by the combination of bentonite and illite, but a trend of increased growth performance was observed in the control groups. Total nitrogen content and pH in the litter decreased following supplementation with the combination of bentonite and illite (p<0.05) when compared with the control group. This data indicates that the dietary supplementation with the combination of bentonite and illite (1% level) has no positive effect on the growth performance and litter quality of Pekin ducks.