• Journal of international Conference on Electrical Machines and Systems
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• v.1 no.2
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• pp.53-57
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• 2012

The mathematical model of a three-phase voltage source pulse-width modulation (PWM) DC/AC inverter is non-linear, and in view of the traditional linear control strategy it can not meet the requirements of designing a high-performance inverter. What's more, when the loads are not pure resistive loads, the inverter further requires that the controller possess high-performance. This paper proposes a nonlinear control strategy for the inverter called Passivity-based Control. We can alter the inverter model in three-phase abc coordinate to two-phase synchronous rotating dq coordinate for establishing the port-control Hamiltonian (PCH) model for this system. We can control the distribution of energy in the system to achieve the control aim. Simulation results show that the passivity-based control method can make this system possess a level of high-performance that is both robust and dynamic.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.34-37
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• 2001

In this paper the comparison of conventional PI control and nonlinear sliding mode control is presented for Switched Reluctance Motor(SRM). SRM drives require a nonlinear controller for high dynamic Performance but the high nonlinearity makes a poor performance in conventional PI control. However SRMs with sliding mode control achieve a robust performance for speed control. In this paper nonlinear sliding mode controller is suggested for high performance speed. State equation and modeling are proposed. And we present the speed comparison of PI control and SLMC.

• IEMEK Journal of Embedded Systems and Applications
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• v.17 no.3
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• pp.185-190
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• 2022

We propose a high speed data communication method for motor drive systems with fast control cycle in order to collect state variables of motor control without degrading control performance. Ethernet is chosen for communication device, and multi-core DSP architecture is exploited for communication processing load distribution. The communication program including network protocol stack and motor control program are assigned to two separate cores, and data between two cores are exchanged using interrupt-based inter-process communication mechanism, which enables to achieve a high-speed communication performance without degrading the motor control performance. The performance of developed communication method is demonstrated by real experiments using TCP, UDP and Raw Socket protocols in an experimental setup consisting of TI's TMS320F28388D motor control card and MS Windows PC.

• KIEAE Journal
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• v.15 no.3
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• pp.21-28
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• 2015

Purpose: In this study, we analyzed the energy performance levels and high-performance technology trends through the case studies of foreign high-performance buildings. Method: Buildings built within 10 years were selected for the analysis of recent trends. we analyzed the buildings of U.S.A, Germany and Japan using LEED certified buildings, Passive House certified buildings and CASBEE certified buildings database for the case study of foreign high-performance buildings. A total of 20 high-performance buildings including 14 cases in U.S.A, 4 cases in Germany and 4 cases in Japan were selected. Annual energy consumption levels for 20 high-performance buildings were collected with the actual energy consumption data or data from simulation programs officially recognized by DOE. Annual energy consumption were compared with the energy performance standard of the office buildings in the CBECS database, ASHRAE Standard 90.1-2004 and Building Energy Efficiency Rating System in Korea. Result: The order of the green strategies applied in the main categories are Renewable Energy(63%), Indoor Environment Control(51%), Envelope Improvement(44%) and HVAC System & Control(28%). Specified strategies most widely used in the sub-categories are high-performance Insulation (70%), High Efficiency Heating, Cooling Source Equipment(85%), Photovoltaic&Solar Thermal(80%) and Daylighting(80%).

• Proceedings of the KIEE Conference
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• 2002.06a
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• pp.135-141
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• 2002

This paper presents an implementation of high-dynamic performance of position sensorless motion control system of Reluctance Synchronous Motor(RSM) drives for an industrial servo system with direct torque control(DTC), The problems of DTC for high-dynamic performance and maximum efficiency RSM drive due to a saturated stator linkage flux and nonlinear inductance curve with various load currents, The accurate estimation of the stator flux and torque are obtained using stator flux observer of which a saturated inductance Ld and Lq can be compensated by adapting from measurable the modulus and angle of the stator current space vector. To obtain fast torque response and maximum torque/current with varying load current, the reference command flux is ensured by imposing Ids=Iqs. This control strategy is proposed to fast response and optimal efficiency for RSM drive. In order to prove rightness of the suggested control algorithm, the actual experiment carried out at ${\pm}$20 and ${\pm}$1500 rpm. The developed digitally high-performance control system are shown some good response characteristic of control results and high performance features using 1.0kW RSM of which has 2.57 Ld/Lq salient ratio.

• Journal of Korean society of Dental Hygiene
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• v.21 no.5
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• pp.675-683
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• 2021

Objectives: This study aimed to verify the relations of COVID-19 infection-related knowledge, dental infection control performance, and psychosocial health of dental hygienists. Methods: From the data was analyzed through the frequency analysis, t-test, one way ANOVA, and pearson's correlation analysis with a total of 198 dental hygienists using SPSS Statistics 21.0. Results: The correct answer rate for knowledge about COVID-19 was higher with a bachelor's degree or higher. Thus, when the level of education was higher, the performance was also high (p<0.01). COVID-19 infection control performance was highly shown in case of high age (4.43) (p<0.05) and the married (4.42) (p<0.01). Infection control performance was high when they had an educational experience of COVID-19 infection control (4.46), and when the infection control guidebooks were equipped in their workplaces (p<0.001). Degree of psychosocial health of research subjects was shown in the order of potential stress (60.6%), high-risk stress (23.7%), and healthy (15.7%). Infection control performance was higher, the psychosocial health was healthy. Conclusions: For the response to COVID-19 infectious disease and the preparation for mutated viruses and new infectious diseases in the future, it would be necessary to establish the concrete measures for establishing the strict infection control system for dental clinics and also enhancing the psychosocial health of dental hygienists.

• Journal of Institute of Control, Robotics and Systems
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• v.6 no.12
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• pp.1053-1060
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• 2000

In this paper, a discrete-time variable structure control method using recursively defined switching function and a decoupled variable structure disturbance compensator is used to achieve high performance circular motion control of a CNC machining center. The discrete-time variable structure control with the decoupled disturbance compensator method developed in this paper uses a recursive switching function defined as the sum of the current tracking error vector and the previous value of the switching function multiplied by a positive constant less than one. This recursive switching function provides much improved performance compared to the method that uses a switching function defined only as a linear combination of the current tracking error. Enhancements in tracking performance are demonstrated in the circular motion control using a CNC milling machine.

• Research in Community and Public Health Nursing
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• v.11 no.2
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• pp.389-398
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• 2000

The work of visiting nursing personnel consists mostly of direct nursing and it is absolutely necessary that training of the nursing personnel for infection control be emphasized because most of patients are composed of elderly people with chronic diseases and malnutrition who are highly susceptible to infection. Accordingly. this study was designed to provide basic data for the development of an infection control program in public health centers as well as the promotion of perception and performance of infection control by analysing the perception of importance and performance in the infection control of visiting nursing personnel who carry out visiting nursing services. The subjects of this study consisted of a number of visiting nursing personnel working for 15 public health centers. 15 health-center branches. and 16 health clinics. The collection of data was grounded on a questionnaire method. The questionnaire breaks down to 8 questions about general characteristics and 108 questions in connection with the perception and performance of infection control. The results of this study are as follows: 1. 82 subjects (78.1%) responded that it is necessary to control infection. 79 subjects(75.3%) responded that education is necessary for infection control. 50 respondents (47.6%) answered in the affirmative in regard to the role of infection carriers. 2. The mean score for the perception of importance in infection control was 4.55 and that performance accounts for 4.03. this turns out to be very high. 3. In terms of the perception of importance per each field of infection control. medication. the management of contamination and sterilization, the control of environments and instruments. washing hands and individual hygiene as well as the prevention of cross-infection and the supervision of infection stand at 4.72. 4.64. 4.60. 4.58. 4.52 and 4.21 respectively. In terms of performance. the supervision of infection. the control of environments and instruments, individual hygiene and the prevention of cross infection. medication. washing hands, and the management of contamination and sterilization was 4.21. 4.12. 4.10. 4.03. 3.91 and 3.81 respectively. 4. In terms of the correlation between the perception of importance and the performance of infection control. the score stands high in all fields: this means the high perception of importance leads to high performance statistically (P< .05). 5. In terms of the perception of importance in general characteristics. there is no significant difference while the form of working places. working career and the career as visiting nursing personnel show a significant difference in terms of performance(P< .05). From the results. it is suggested that the visiting nursing personnel should be constantly educated with the aid of the development of infection control programs and that instructions and instruments for the management of infection should be worked out so as to enhance the performance of infection control on the part of nurses in applicable communities.

• The Transactions of the Korean Institute of Power Electronics
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• v.7 no.5
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• pp.427-436
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• 2002

This paper presents an implementation of high-dynamic performance of position sensorless motion control system of Reluctance Synchronous Motor(RSM) drives for an industrial servo system with direct torque control(DTC). The problems of high-dynamic performance and maximum efficiency RSM drives controlled by DTC are saturation of stator linkage flux and nonlinear inductance characteristics with various load currents. The accurate estimation of the stator flux and torque are obtained using stator flux observer of which a saturated inductance $L_d$ and $L_q$ can be compensated by adapting from measurable the modulus of the stator current and rotor position. To obtain fast torque response and maximum torque/current with varying load current, the reference command flux is ensured by imposing $I_{ds} = I_{qs}$. This control strategy is proposed to achieve fast response and optimal efficiency for RSM drive. In order to prove rightness of the suggested control algorithm, the actual experiment carried out at $\pm$20 and $\pm$1500 rpm. The developed digitally high-performance motion control system shown good response characteristic of control results and high performance features using 1.0kW RSM which has 2.57 Ld/Lq salient ratio.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.7
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• pp.9-15
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• 2012

This paper is proposed the adaptive fuzzy neuro controller(AFNC) for high performance of induction motor drive. The design of this algorithm based on the AFNC that is implemented using fuzzy controller(FC) and neural network(NN). This controller uses fuzzy rule as training patterns of a NN. Also, this controller adjusts the weights between the neurons of NN to minimize the error between the command output and the actual output using the back-propagation method. The control performance of the AFNC is evaluated by analysis in various operating conditions. The results of analysis prove that the proposed control system has high performance and robustness to parameter variation, and steady-state accuracy and transient response.