• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 1999.10a
• /
• pp.216-220
• /
• 1999

In this paper, the feedback linearization technique is used with the sliding mode control for nonlinear system. The combination of these two control techniques can be achieved by proposing a novel sliding surface which has the nonminal dynamics of the original system controlled by feedback linearization technique. The noble design of the sliding surface is based on the augmented system whose dynamics have a higher order than that of the original system. The reaching phase is removed by using an initial virtual state which makes the initial sliding function equal to zero

• Journal of the Korean Institute of Navigation
• /
• v.23 no.2
• /
• pp.1-9
• /
• 1999

A trailer truck is a major equipment for transporting containers, and its driving is difficult due to two degrees of freedom which exist in the joint part between truck and trailer. Especially Backing a trailer truck to a parking home is a difficult exercise for all but the most skilled truck drivers. Normal driving instincts lead to erroneous movements. When watching a truck driver backing toward a parking home, one often observes the driver backing, going forward, backing again, going forward, etc., and finally backing to the desired position along the parking home. This paper discusses the design of the controller to control the steering of a trailer truck while only backing up to a parking home from an initial position. In this paper, we propose a backing up control system for a container trailer truck using fuzzy theory where the primitive fuzzy control rules are macroscopically designed using an expert's knowledge, and the control rules are regulated by LIBL(Linguistic Instruction Based Learning) to enable to back up successfully the trailer tuck to a parking home from arbitrary initial position. The validity of the proposed parking control system is shown by applying it to some initial positions on the simulator for container trailer truck.

• Journal of the Korean Institute of Telematics and Electronics
• /
• v.12 no.4
• /
• pp.15-20
• /
• 1975

The power overshoot is rises in the output during the transient period when the output of nuclear reactor is increased from the initial state to the desired target state and certain amount of constraint on power level is of primary importance for safety control of nuclear reactor. Therefore, the maximum principle is applied to this process control in transfering its power from the initial state(no, co) to the final target state(2no, 2co or 1.5no, 1.5co), adjusting the reactivity so that its overshoot is limited within the allowable constraint required. In this case, the switching points, switching times, optimal lima and optimal control reactivity are calculated.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.22 no.10
• /
• pp.8-17
• /
• 2008

This paper presents a stable lighting method for HID lamp for ship from initial discharging current limit with discharging voltage control. The output voltage of the proposed control scheme is boosted for ignition, and the charging voltage is decreased by the resistor discharging. The proposed controller fires the initial discharge at the designed discharging voltage to limit the discharge current. After the discharging, constant current controller is used for brightness in steady state. The proposed control scheme can limit the initial discharge current using the starting point control without a complex voltage controller. so it can improve the life-time of HID lamp and get a stable discharge from restricted the initial discharge current. In order to improve the protection of the system, a simple instantaneous error detecting circuit for open state and short state of HID lamp is used. The proposed error detecting of HID lamp can protect the power system of lamp control. The effectiveness of the proposed controller is verified from the experiments of practical 2.5[kW] HID search light for ship.

• The korean journal of orthodontics
• /
• v.24 no.1 s.44
• /
• pp.1-15
• /
• 1994

This study was attempted to explore the relationship between locus of control and the discomfort of the patients at the initial stage of the orthodontic treatment. Locus of control was measured by 'Locus of Control(LOC) scale for children' and 'Orthodontic Locus of Control(OLOC) scale for children'. The discomfort was measured by 'discomfort index card' in 52 children and adolescent patients who initiate orthodontic treatment. In addition, locus of control of the patients' mothers was measured by 'Orthodontic Locus of Control(OLU) scale for parents'. The results were as follows : 1. The test-retest reliability of 'Locus of Control(LOC) scale for children' and 'Orthodontic Locus of Control(OLOC) scale' was in the moderate to high range. 2. Out of 52 patients, 47 showed moderate to severe discomfort following placement of an initial archwire. The patients showed the most severe discomfort on the first day, and most of the discomfort was manifested within the first 3 days, then decreased until the 7th day. There was no significant difference in the discomfort according to sex and age. 3. The discomfort of the patients was the highest in the morning session when a day was divided into 4 sessions, i.e., morning, afternoon, evening, and night. 4. In the score of 'Locus of Control(LOC) scale for children' and 'Orthodontic Locus of Control(OLOC) scale for children', the group of internal locus of control expressed more discomfort than the group of external locus of control. And there was no significant correlation between locus of control of the patients and that of their mothers. 5. There was no significant difference in the score of locus of control according to sex and me. However, the score of boys tended to be lower than that of girls and the score of primary school students higher than that of middle and high school students.

• Journal of Korean Academy of Nursing
• /
• v.35 no.5
• /
• pp.842-849
• /
• 2005

Purpose: The main purpose of this study was to establish a nursing intervention data base to improve maternal attachment. Method: The first group of mothers( control group), experienced their first physical contact with their infants after being discharged from the hospital. The second group (experimental group) practiced early initial mother-infant postpartum contact known as the most sensitive period for founding maternal-infancy attachment. The subjects of this study gave birth to normal infants at M hospital from Aug.25 to Sept.30, 2004. During the same time, data was collected through direct observation, with instruments designed by Cropley et al., to assess the behaviors of normal attachment. The statistical methods for data analysis were percentage, mean, standard deviation and t-test with an SPSS program. Result: The group practicing initial mother-infant contact, showed a higher degree of physical and functional bonding than the group experiencing the first contact after discharge from the :10spital (control group)(p<.0l). The group practicing initial mother-infant contact, showed higher degrees of bonding attachment assessments than the group experiencing their first initial contact after their discharge from the hospital(p<.01). Conclusion: The group practicing early mother-infant contact, showed more maternal-infant interaction than the group experiencing their initial contact after their discharge from the hospital. These results show that maternal attachment behavior increases according with an early initial mother-infant contact.

• Journal of Power Electronics
• /
• v.14 no.3
• /
• pp.564-571
• /
• 2014

Rotor initial position is an important factor affecting the control performance of electrically excited synchronous motors. This study presents a novel method for estimating rotor initial position based on sliding discrete Fourier transform (sDFT). By injecting an ac excitation into the rotor winding, an induced voltage is generated in stator windings. Through this voltage, the stator flux can be obtained using a pure integral voltage model. Considering the influence from a dc bias and an integral initial value, we adopt the sDFT to extract the fundamental flux component. A quadrant identification model is designed to realize the accurate estimation of the rotor initial position. The sDFT and high-pass filter, DFT, are compared in detail, and the contrast between dc excitation and ac injection is determined. Simulation and experimental results verify that this type of novel method can eliminate the influence of dc bias and other adverse factors, as well as provide a basis for the control of motor drives.

• Journal of Power Electronics
• /
• v.5 no.1
• /
• pp.11-19
• /
• 2005

This paper describes the two control techniques to perform the sensorless vector control of a PMSM by injecting the high frequency voltage to the stator terminal. The first technique is the estimation algorithm of the initial rotor position. A PMSM possesses the saliency which produces the ellipse of the stator current when the high frequency voltage is injected into the motor terminal. The major axis angle of the current ellipse gives the rotor position information at a standstill. The second control technique is a sensorless control algorithm that injects the high frequency voltage to the stator terminal in order to estimate the rotor position and speed. The rotor position and speed for sensorless vector control is calculated by appropriate signal processing to extract the position information from the stator current at low speeds or standstill. The proposed sensorless algorithm using the double-band hysteresis controller exhibits excellent reference tracking and increased robustness. Experimental results are presented to verify the feasibility of the proposed control schemes. Speed, position estimation and vector control were carried out on the floating point processor TMS320VC33.

• Journal of Institute of Control, Robotics and Systems
• /
• v.10 no.12
• /
• pp.1241-1248
• /
• 2004

A controller of wheeled mobile robot(WMR) based on Lyapunov theory is designed and a Fuzzy-Neural Network algorithm is applied to this system to adjust controller gain. In conventional controller of WMR that adopts fixed controller gain, controller can not pursuit trajectory perfectly when initial condition of system is changed. Moreover, acquisition of optimal value of controller gain due to variation of initial condition is not easy because it can be get through lots of try and error process. To solve such problem, a Fuzzy-Neural Network algorithm is proposed. The Fuzzy logic adjusts gains to act up to position error and position error rate. And, the Neural Network algorithm optimizes gains according to initial position and initial direction. Computer simulation shows that the proposed Fuzzy-Neural Network controller is effective.

• Kyungpook Mathematical Journal
• /
• v.48 no.3
• /
• pp.395-410
• /
• 2008

A one site chemotherapy agent-diffusion model is proposed which accounts for diffusion of chemotherapy agent, normal and cancer cells. It is shown that, by controlling the initial conditions, consequently an initial dose of the chemotherapy agent, the system is guaranteed to evolute towards a target equilibrium state. Or, growth of the normal cells occurs against decay of the cancer cells. Effects of diffusion of chemotherapy-agent and cells are investigated through numerical computations of the concentrations in square and triangular cancer sites.