• International Journal of Naval Architecture and Ocean Engineering
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• 제9권1호
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• pp.55-65
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• 2017

Underwater torpedo has control fin with very low aspect ratio due to launching from limited size of cylindrical torpedo tube. If the aspect ratio of control fin of underwater vehicle is very low three-dimensional flow around control fin largely reduces control forces. In this study, the end plate was applied to reduce the three-dimensional flow effects of partially movable control fin of underwater vehicle. Through numerical simulations the flow field around control fin was examined with and without end plate for different flap angles. The pressure, vorticity, lift and torque on the control fin were analyzed and compared to experiments. The comparison have shown a reasonable agreement between numerical and experimental results and the effect of end plate on a low aspect ratio control fin. When the end plate was attached to the movable control fin, the lift increased and the actuator shaft torque did not significantly change. As this means less consumption of the actuator shaft torque compared to the control fin that has the same control force, the inner actuator capacity can be reduced and energy consumption can be saved. Considering this, it is expected to be effectively applied to the control fin design of underwater vehicles such as torpedoes.

• Structural Engineering and Mechanics
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• 제52권2호
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• pp.275-290
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• 2014

In this paper, Simple Adaptive Control (SAC) method is used to mitigate the detrimental effects of earthquakes on MR-damper equipped structures. Acceleration Feedback (AF) is utilized since measuring the acceleration response of structures is known to be reliable and inexpensive. The SAC is simple, fast and as an adaptive control scheme, is immune against the effects of plant and environmental uncertainties. In the present study, in order to translate the desired control force into an applicable MR damper command voltage, a neural network inverse model is trained, validated and used through the simulations. The effectiveness of the proposed AF-based SAC control system is compared with optimal H2/LQG controllers through numerical investigation of a three-story model building. The results indicate that the SAC controller is substantially effective and reliable in both undamaged and damaged structural states, specifically in reducing acceleration responses of seismically excited buildings.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.492-495
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• 1997

Integral type system is that a system is represented by a proper rational function. In this paper, novel control scheme based on model reference approach is proposed for integral type system. The proposed scheme compensates various undesirable effects of the system. In especially, the proposed scheme applied to DC servo control system, analyzed its control characteristic. Performances of the proposed system show excellent control characteristics; complete compensation of the undesirable nonlinear friction and load viscous, For proving realistic validities, LOS(Line Of Sight) stabilization system which has typically many nonlinear effects is experimented. After executing the computer simulation in "MATLAB", then the results are compared with the experiments. The results are very similar in theoretical study and the proposed control scheme is successfully verified. verified.

• International Journal of Contents
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• 제13권1호
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• pp.22-30
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• 2017

The diffusion of advanced mobile technology has introduced new types of personal information or 'location data'. These new data mean new opportunities for businesses, such as location-based services (LBS), but have resulted in new consumer anxieties regarding disclosure of personal information. This study examines the effects of the consumers' perceived control over "time-andplace" information in location-aware services on their perceived privacy risk. A total of 270 respondents participated in this study. Conditions of perceived privacy control were operationalized over time-and-place information, in a $2{\times}2$ factorial design. Results indicate that the perceived control over time-and-place personal information is a significant predictor of perceived risk, and control assurances over time-and-place information enhances the perception of control, thus alleviating the perceived risk. In addition, the effect is much more significant when time and place were combined.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1994년도 Proceedings of the Korea Automatic Control Conference, 9th (KACC) ; Taejeon, Korea; 17-20 Oct. 1994
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• pp.89-94
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• 1994

This paper presents an impact control algorithm for reducing the potentially damaging effects by interation of redundant manipulators with their environments. In the. proposed control algorithm, the redundancy is resolved at the torque level by locally minimizing joint torque, subject to tire operational space dynamic formulation which maps tire joint torque set into the operational forces. For a given pre-impact velocity of the manipulator, the proposed approach is on generating joint space trajectories throughout the motion near the contact which instantaneously minimize the impulsive force which is a scalar function of manipulator's configurations. This is done by using the null space dynamics which does not affect the motion of an end-effector. The comparative evaluation of the proposed algorithm with a local torque optimization algorithm without reducing impact is performed by computer simulation. The simulation results illustrate the effectiveness of the algorithm in reducing both the effects of impact and large torque requirements.

• 아동학회지
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• 제36권1호
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• pp.47-64
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• 2015

The purpose of this study was to examine the relationships between parents' affectionate parenting behavior, preschooler's effortful control, and conscience. In this study, the subjects consisted of 335 preschoolers ($M_{month}=65.86$) and their parents. The major results of this study were as follows. First, there were positive correlations between parents' affectionate parenting behavior, preschooler's effortful control, and conscience. Second, preschooler's effortful control mediated the effects of affectionate parenting behavior upon preschooler's conscience. Third, preschooler's effortful control(Time 1) had effects upon conscience(Time 2). In conclusion, this study revealed that parents' affectionate parenting behavior and preschooler's effortful control can have a significant impact on the level of preschooler's conscience.

• 아동학회지
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• 제29권4호
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• pp.167-179
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• 2008

This study used Structural Equation Modeling(SEM) to test causal relationships among perceived social supports, self-control, and subjective well-being in a sample of 325 5th and 6th grade elementary school children. Correlations of observed variables showed statistically significant among perceived social support, self-control, and subjective well-being. The goodness-of-fit of the hypothetical structural model in the study, perceived social support having direct effects on self-control and subjective well-being, and self-control, retaining the influence of perceived social support, having effects on subjective well-being-showed fairly acceptable levels. The results revealed that perceived social supports increase children's subjective well-being, and these supports also increase children's self-control, which indirectly influences children's subjective well-being.

• International Journal of Control, Automation, and Systems
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• 제1권2호
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• pp.215-221
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• 2003

The education system in this paper is used to demonstrate and educate the effects of electromagnetic induction. Placing an aluminum ring over the core and switching on AC source causes the ring to jump in the air due to induced currents in the ring producing a magnetic field opposed to that produced in the core. To control the position of the ring by only the current, it is to require nonlinear control algorithm and control board that is composed of photo sensors, decode circuit, computer communication, and power electronics circuit. This paper provides the development for education system in detail and the effects of dynamic neural networks for nonlinear control with on line is studied.

• 소음진동
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• 제8권3호
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• pp.485-493
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• 1998

Many of the adaptive noise control systems utilize a form of the least mean square (LMS) algorithms. In the active control of noise, it is common practice to locate an error microphone far from the control source to avoid the near-field effects by evanescent waves. Such a distance between the control source and the error microphone makes a certain level of time-delay inevitable and, hence, may yield undesirable effects on the convergence properties of control algorithms such as filtered-x LMS. This paper discusses the dependence of the convergence rate on the acoustic error path in these popularalgorithms and introduces new algorithms which increase the convergence region regardless of the time-delay in the acoustic error path. Performances of the new LMS algorithms are presented in comparison with those by the conventional algorithms based on computer simulations and experiments.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1987년도 한국자동제어학술회의논문집; 한국과학기술대학, 충남; 16-17 Oct. 1987
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• pp.364-369
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• 1987

It has recently shown that a solenoid valve can be utilized in a hydraulic position-control system by discontinuous control methods. The objective of this study is to investigate the effects of solenoid valves on the response characteristics of a hydraulic position-control system by applying two kinds of discontinued control methods i.e., Simple On-Off (SOF) and Pusating On-Off(POF) controls. Three types of solenoid valves i.e. low-frequency, closed-center type (LF/C), high-frequency, closed-center type (HF/C), low-frequency, tandem-center type(LF/T) were used in this study. Effects of loading conditions and control parameters on the response characteristics were experimentally examined and compared each other. Pressure transients within the actuator were also studied.