• Korean Journal of Child Studies
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• v.34 no.1
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• pp.1-20
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• 2013

This study examined the emergent literacy development of children and the effects of the home literacy environment on it. 861 pairs each-consisting of a mother and a child aged from three to six years old were asked to complete the early literacy parent questionnaire (Boudreau, 2005) and the home literacy environment questionnaire (Park & Kim, 2008). The results showed that : (1) girls achieved higher scores than boys in emergent literacy and its subcategories. (2) there were age differences in all of the subcategories of emergent literacy except the categories of 'orientation toward literacy' and 'phonological awareness'. (3) The study revealed that 'reading books' in the home literacy environment was the most contributive variable in predicting emergent literacy after controlling the age and gender followed by 'literacy learning'

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.433-434
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• 2018

Smart farm technology that combines 4th industrial technology and agriculture is expected to be a solution to agriculture in Korea which is getting worse due to aging and population decrease. The development of smart farm technology is considered to be important, and the method of designing and accessing and controlling data is described.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 1999.10a
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• pp.273-280
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• 1999

Yard cranes are very useful equipments for handing of heavy containers, But rope-driven yard cranes must have a little of sway and skew motion because ropes are passive mechanical device. Therefore rope-driven yard cranes require skilled drivers to depress sway and skew motions. So many researches have been concentrated on anti-sway and anti-skew algorithm controlling trolley speed or rope tension. Although many efforts, the rope-driven method is not proper to an automated yard equipment because of sway and skew motion. This paper will propose a new concept yard crane which has a new structure, overcomes defects of rope-driven cranes and is proper to automation. And we will study its actuality

• Smart Structures and Systems
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• v.5 no.1
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• pp.55-68
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• 2009

In the present study, active control of a smart beam under forced vibration is analyzed. The aluminum smart beam is composed of two piezoelectric patches and strain gauge. One of the piezoelectric patches is used as controlling actuator while the other piezoelectric patch is used as vibration generating shaker. The smart beam is harmonically excited by the piezoelectric shaker at its fundamental frequency. The strain gauge is utilized to sense the vibration level. Active vibration reduction under harmonic excitation is achieved using both strain and displacement feedback control. Control actions, the finite element (FE) modeling and analyses are directly carried out by using ANSYS parametric design language (APDL). Experimental applications are performed with LabVIEW. Dynamic behavior at the tip of the beam is evaluated for the uncontrolled and controlled responses. The simulation and experimental results are compared. Good agreement is observed between simulation and experimental results under harmonic excitation.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.09a
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• pp.236-239
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• 2003

In this paper, we investigate the issues for the design and implementation of tele-operation system based on the haptic interface. Here, the 3-DOF haptic device and the x-y-z stage are employed as master controller and slave system respectively. In this master-slave system, the force feedback algorithm, the modeling of virtual environments and the control method of x-y-z stage are proposed. In this paper, inernet network is used for data communication between master and slave. We construct virtual environment of the real convex surface from the force-feedback in controlling the X-Y-Z stage and getting the force applied by the 3-DOF haptic device.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.10a
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• pp.291-295
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• 2009

Economic and environmental concerns over fossil fuels encourage the development of photovoltaic(PV) energy systems. Due to the intermittent nature of solar energy. energy storage is needed in a stand-alone PV system for the purpose of ensuring continuous power flow. Grid-connected PV system that supply power in a critical load demand require to curb power fluctuation. In this case. SCB is a effectiveness in controlling power variation due to intrinsic PV system. We propose the Matlab/Simulink dynamic model and power flow characteristics of a hybrid energy system with PV and SCB.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.11
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• pp.753-759
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• 2004

This paper presents a modeling and simulation of a fuzzy controller for maximum power extraction of a grid-connected wind energy conversion system with a link of a rectifier and an inverter. It discusses the maximum power control algorithm for a wind turbine and proposes, in a graphical form, the relationships of wind turbine output, rotor speed, power coefficient, tip-speed ratio with wind speed when the wind turbine is operated under the maximum power control. The control objective is to always extract maximum power from wind and transfer the power to the utility by controlling both the pitch angle of the wind turbine blades and the inverter firing angle. Pitch control method is mechanically complicated, but the control performance is better than that of the stall regulation method. The simulation results performed on MATLAB will show the variation of generator's rotor angle and rotor speed, pitch angle, and generator output.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.129-133
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• 2005

In this paper, first the thermodynamic model is presented to one of the super heaters and sprays of the Nekka power plant and then its unknown parameters are identified according to the registered data of the power plant. SCO control method is introduced to control the external steam temperature of super heater. Finally the conventional method in power plant for controlling external steam temperature of super heater is compared with new method and their performances are presented..

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.8
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• pp.916-926
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• 1988

In this paper, we explore real-time implementation of various dynamic control algorithms, which use the different levels of the information of the dynamics, using a SCARA type robot to show the feasibility and effectiveness of such algorithms. For these purposes, the kinematics of the SCARA type robot is anayzed and the manipulator-actuator dynamic equations based on Lagrange mechanisms are derived. Experimental results indicate that computed torque technique and iterative learning control methods perform better than classical PID control and that these algorithms can be effectively applied to controlling industrial manipulators.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.78.3-78
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• 2002

In this paper, we present a five-DOF actuator based on dielectric elastomer. The actuator is designed for generating five DOFs motions to drive a micro camera steering module and provides all the functions for controlling CCD array such as focusing, pan and tilting. Basic modeling of the actuator is performed, and simulation works and experimental verifications are conducted, too. The camera steering module includes most parts necessary for driving the actuator such as a micro-controller and DC-DC converter, etc. It can be operated with a personal computer using only communication lines without external power supply. A prototype is developed and its performance is experimentally proved. $\textbullet$ artificial muscle, EAP, actuator.