• Proceedings of the IEEK Conference
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• 2002.06c
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• pp.181-184
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• 2002

This paper describes remote control RS232 communication using internet service, safety of exchange data and internet traffic by Denial of Service Attacks. In case of Denial of service Attacks, it makes connection of internet service failed. So in this Paper, this solution was examined and implemented for receiving data in safety against Denial of Service Attacks by LabVIEW program of National Instruments.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.1
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• pp.110-122
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• 2008

Pneumatic vibration isolator typically consisting of dual-chamber pneumatic springs and a rigid table are widely employed for proper operation of precision instruments such as optical devices or nano-scale equipments owing to their low stiffness- and high damping-characteristics. As environmental vibration regulations for precision instruments become more stringent, it is required to improve further the isolation performance. In order to facilitate their design optimization or active control, a more accurate mathematical model or complex stiffness is needed. Experimental results we obtained rigorously for a dual-chamber pneumatic spring exhibit significantly amplitude dependent behavior, which cannot be described by linear models in earlier researches. In this paper, an improvement for the complex stiffness model is presented by taking two major considerations. One is to consider the amplitude dependent complex stiffness of diaphragm necessarily employed for prevention of air leakage. The other is to employ a nonlinear model for the air flow in capillary tube connecting the two pneumatic chambers. The proposed amplitude-dependent complex stiffness model which reflects dependency on both frequency and excitation amplitude is shown to be very valid by comparison with the experimental measurements. Such an accurate nonlinear model for the dual-chamber pneumatic springs would contribute to more effective design or control of vibration isolation systems.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.741-746
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• 2004

We propose a new technique to the design and real-time implementation of an adaptive controller for robotic manipulator based on digital signal processors in this paper. The Texas Instruments DSPs(TMS320C80) chips are used in implementing real-time adaptive control algorithms to provide enhanced motion control performance for dual-arm robotic manipulators. In the proposed scheme, adaptation laws are derived from model reference adaptive control principle based on the improved direct Lyapunov method. The proposed adaptive controller consists of an adaptive feed-forward and feedback controller and time-varying auxiliary controller elements. The proposed control scheme is simple in structure, fast in computation, and suitable for real-time control. Moreover, this scheme does not require any accurate dynamic modeling, nor values of manipulator parameters and payload. Performance of the proposed adaptive controller is illustrated by simulation and experimental results for a dual arm robot consisting of two 4-d.o.f. robots at the joint space and cartesian space.

• 한국정보디스플레이학회:학술대회논문집
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• 2006.08a
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• pp.625-630
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• 2006

A new method to get reliable viewing angle measurements on LCD reflective display is presented. This method is based on the use of commercial Fourier optics viewing angle instruments already proposed by ELDIM for more than 15 years. This apparatus is capable to measure simultaneously quasi all the incidence and azimuth angles and to control very precisely the illumination of the sample. We show that, in contrast to other instruments, a clever illumination procedure with two different conditions allows separation of the intrinsic reflective contribution of the display and of the parasitic front end reflection. In this way, intrinsic performances of the display can be obtained at any incidence and azimuth angles and realistic observer conditions can be simulated.

• Korean Journal of Child Studies
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• v.29 no.6
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• pp.1-14
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• 2008

This study explored relationships between internal locus of control, ego-resilience, and behavior problems including effects of ego-resilience as mediating variables of behavior problems in 135 institutionalized children. Instruments were the Locus of Control (Min, 1999) and Ego-resilience (Yoon et al. 2001) scales and Korea-Child Behavior Checklist (Oh et al., 1997). Locus of control was administered to the children; ego-resilience and behavior problems were rated by teachers. Findings were that (1) internal locus of control related positively to ego-resilience and negatively to behavior problems; ego-resilience related negatively to behavior problems. (2) Effects of internal locus of control on behavior problems were mediated by ego-resilience; ego-resilience sub-factors of peer relationships and comprehension ability mediated relationships between internal locus of control and behavior problems.

• The Journal of Korean Institute for Practical Engineering Education
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• v.4 no.1
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• pp.65-71
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• 2012

This paper introduces computer based practice for engineering education through using NI-ELVIS and virtual instruments of LabVIEW as application software. Different laboratory experiments "Labs" will be presented as convenient paradigms of adopting computer based practice for the efficacy of engineering education. Remote labs as web/internet or network-enabled controlled by remote server computer have been extensively used by a number of universities, national laboratories and companies for different kind of application around the globe. Overtime, as technology proceed in its progress, more developed techniques are being used particularly in the field of engineering education.

• Journal of Korean Elementary Science Education
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• v.32 no.2
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• pp.198-205
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• 2013

For assessing classroom environment, numerous instruments were developed and reported the survey results for science students in science education. In this study I translated Constructivist Learning Environment Scales (CLES) were into Korean versions for elementary school teachers, and measured the reliability. The subjects were randomly selected from three departments of an University of Education in a metropolitan city. All of them were 110 students, who would be elementary school teachers. According to the survey results, pre-service teachers for elementary school have recognized constructivistly for learning environments in an actual forms. In a scale of student negotiation they have most constructivistly recognized learning environment, and moderately in scales of relevance, uncertainty and critical view while they have seldom constructivistly recognized in a scale of shared control. Also Korean version CLES would be an reliable instruments for constructivist assessing learning environments.

• Proceedings of the KIEE Conference
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• 1998.07b
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• pp.807-809
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• 1998

Plant Protection Systems(PPS) are those systems that initiate safety actions to mitigate the consequences of design basis events by sending signals to Reactor Trip Switch Gear System(RTSS) and Engineered Safety Features-Component Control Systems(ESF-CCS). This paper illustrates distinctive features and improved design concepts of Korea Next Generation Reactor(KNGR) based on the experience obtained through prototyping of PPS.

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.736-741
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• 1998

It is well known that an encoder or a resolver is necessary to obtain the position data for speed or position control Generally utilized speed sensors are mal-affected by the EMI, dusty, and high temperature surroundings. Therefore, the speed and position sensorless controls using observers have been studied widely. In this paper, the binary observer which is composed of two feedback regulation loops to control the speed of SRM(Switched Reluctance Motor) is applied. One loop compensates the control input directly like the sliding mode control, and the other one compensates the system parameters indirectly. This observer is constructed on the foundation of variable structure control on the foundation of variable structure control theory and has the inertial term for the varying parameter. The validities of this proposed method is proved by experiments.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.1006-1008
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• 2003

Position controls are very important in semiconductor manufacturing devices, machine tools precision measuring instruments, etc. to measure the distance of movement of moving objects in minute units and the accuracy of measurement for the moving distance in these devices affect the performance of the whole devices. Therefore, in those precision instruments, a sensing device that can measure the distance of movement with high-precision resolution is required. In this paper, a novel encoder of digital and analog hybrid type is proposed. It is shown that from this experiment a high-resolution angle measurement device can be designed by a low cost incremental encoder.