• Journal of Auto-vehicle Safety Association
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• v.13 no.1
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• pp.6-13
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• 2021

This paper presents yaw moment control for modification of steering characteristic in rear-driven vehicle with front in-wheel motors (IWMs). The proposed control algorithm is designed to modify yaw rate response of the test vehicle. General approach for modification of steering characteristic is to define the desired yaw rate and track the yaw rate. This yaw rate tracking method can cause the chattering problem because of the IWM actuator response. Large overshoot and settling time in IWM torque response can amplify the oscillation in control input and yaw rate. To resolve these problems, open-loop IWM controller for cornering agility was designed to modify the understeer gradient of the vehicle. The proposed algorithm has been investigated via the computer simulations and the vehicle tests. The performance evaluation has been conducted on dry asphalt using E-segment test vehicle. The performance of the proposed algorithm has been compared to general yaw rate tracking algorithm in the vehicle tests. It has been shown that the proposed control law improved the cornering agility without chattering problem.

• Korean Journal of Microbiology
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• v.10 no.1
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• pp.35-40
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• 1972

1) The photodecomposition rate of guanine being catalized by methylene blue ws 53.7% in contrast with 9.3% that of dark control for 180 min. 2) In guanine control, the decomposition rate was very low. For 180 min., the rate was 8.1% in illuminated sample and 3.9% in non-illuminated sample. 3) The decomposition rate of methylene blue was obviously interfered by the existence of guanine. In guanine and methylene blue mixture solution, the net decomposition rate, excluding that of dark control ws 39.2% and in dye only solution, it was 48.5%.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.60.4-60
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• 2002

Nonlinear adaptive control for the laboratory pressure-flow model. Control valves are installed on both sides. The pressure and the outlet flow rate are measured. The pressure and outlet flow rate are controlled variables and the control valve stem positions on both sides are the manipulated variables. The variation in both inputs will influence both controlled variables. The control performance is good, in spite of varying valve coefficients of inlet and outlet.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.190-190
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• 2000

This paper presents a multirate state feedback control (MRSFC) method for systems sensitive to disturbance and noise based on the multirate estimator design using the current estimator. MRSFC updates the controller output slower than the measurement sampling frequency of system output by a lifting factor R=T$\sub$c//T$\sub$s/. The closed-loop MRSFC system is less sensitive to disturbance and noise due to filtering effect than the conventional single-rate control system. The multirate estimator gain is obtained from solving a conventional pole placement problem such that MRSFC has the same spectrum of eigenvalues in the s-plane as the single-rate control. We applied the proposed multirate state feedback controller to a galvanometer servo system. Simulation and experimental results show that settling and tracking performances are improved compared with a conventional single-rate pole placement control (PPC).

• PNF and Movement
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• v.16 no.2
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• pp.161-168
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• 2018

Purpose: This study aimed to investigate the effects of postural control exercise on the delayed heart rate increase in heart transplant patients. Methods: The subject was a female heart transplant recipient who had a delayed increase in heart rate during exercise. The intensity of exercise was performed at MBorg level 4. The A-B-A' and A-B-A'-B' designs were used to identify the changes in heart rate during active-assisted exercise, lower limb postural control exercise, and upper limb postural control exercise. Experiments were performed for four weeks. The heart rates at pre- and post-exercise were compared, and the time to reach MBorg 4 was measured. Results: In the active-assisted exercise, the average heart rates at pre- and post-exercise and after 10 min of exercise were 88, 89, and 87.7 bpm, respectively. In the repetitive comparison of pre- and post-exercise in the lower limb postural control exercise, the difference in the mean heart rate was 3.5 and 3 bpm in stable support and 14 and 14.5 bpm in unstable support, respectively. In the repetitive comparison of pre- and post-exercise in the upper limb postural control exercise, the difference in the mean heart rate was 6 and 4 bpm in stable support and 4 and 4.5 bpm in unstable support. The time required to reach MBorg 4 was short when both the upper and lower postural control exercises were performed in an unstable state. Conclusion: We suggest that combining proper postural control exercise with strength exercise and aerobic exercise, among others, may be effective in rehabilitating patients in the recovery stage after a heart transplant.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.5
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• pp.87-95
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• 2000

The numerical analysis and the experiments are carried out to develop the design program for the flow control valve attached to the vane pump for power steering. The factors affecting the flow rate characteristics are analyzed by the experiments and the numerical analysis. The results are summarized as follows; (1) the main factors affecting to the first and second control flow rate are the diameter of big and small rod of the spool. (2) the cut off is mainly affected by the main spring constant, the initial displacement of main spring and the small diameter of the spool. (3) the dropping slope characteristics are decided by the chamfer of spool and the dynamic characteristics of the spool.

• 한국연소학회:학술대회논문집
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• 1999.10a
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• pp.129-138
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• 1999

In this paper, our main issue is that establishing the control procedure of continuous gas flow rate according to combustion fan RPM. For this, first, we decide the optimum operating condition of gas swirl burner through analysis of combustion characteristics - thermal efficiency, combustion efficiency and exhaust gases such as CO, $CO_{2}$, $O_{2}$, $NO_{x}$ and THC. Second, fuel gas flow rate of gas valve is decided with considering excess air ratio and combustion fan RPM is decided by the target of combustion air flow rate. Finally, experimental operating equation is acquired by regression for gas valve and combustion fan. This equation is the control equation of continuous gas flow rate and always gas flow rate is decided by combustion fan operating RPM.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.4
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• pp.83-90
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• 1998

In this paper, we present neural network for control of Left Ventricular Assist Device(LVAD) system with a pneumatically driven mock circulation system. Beat rate(BR), Systole-Diastole Rate(SDR) and flow rate are collected as the main variables of the LVAD system. System modeling is completed using the neural network with input variables(BR, SBR, their derivatives, actual flow) and output variable(actual flow). It is necessary to apply high perfomance control techniques, since the LVAD system represent nonlinear and time-varing characteristics. Fortunately. the neural network can be applied to control of a nonlinear dynamic system by learning capability In this study, we identify the LVAD system with neural network and control the LVAD system by PID controller and neural network feedforward controller. The ability and effectiveness of controlling the LVAD system using the proposed algorithm will be demonstrated by experiment.

• Journal of Biosystems Engineering
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• v.25 no.1
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• pp.11-18
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• 2000

In precision chemical application increment of biological efficacy with less chemical is the virtue. spraying rate and droplet size is closely related to biological efficacy. this study was performed to develope a spray-control-system that could control spraying rate and droplet size independently. Twin-fluid nozzles were selected and tested to certify if the nozzles were suitable for the objective of this study. Characteritics of the nozzles i.e., spraying rte and droplet size change u8nder the changes of spraying pressure and air pressure were statistically modeled. The model had I to 1 matching property between dependent variables and independent variables. Using the property and the model, inverse relationship could be determined between variables. A feedback spray control system was developed and tested with predetermined error of 5 % in pressure. The system showed 4 % error in spraying rate and 9 % error in droplets size. Performance of the system could be upgraded by fine tuning but, in practical sense keeping air pressure in the field sprayer was the bottle neck of commercialization of the spray system.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.11a
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• pp.32-33
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• 2014

In this study, evaluation on weight loss properties of spalling control fiber with heating rates has been conducted. For evaluation of this study, 3types of organic fibers(Polyethylene, Polypropylene, Nylon) are used as spaling control fiber. Also, to evaluate the effect of heating rate to spallin control fiber, heating rates are set as 10, 25℃/min. As a result, the start time of weight loss of fiber with various heating rate was delayed as heating rate was increased.