• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.3
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• pp.281-285
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• 2007

Facilities of electric railway should be maintained only at night and it is necessary to maintain by human power because facilities are installed at a high place. This paper presents the development and application of a real-time data acquisition system for the characteristics measurement of overhead contact wires in electric railway. The system is designed to perform in the telemetry environments that developed to store data by wireless in a live wire state of 25 kV power source. The field test results show that the proposed technique and the developed system can be practically applied to measure characteristics of temperature, displacement, and strain on overhead contact lines.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.645-646
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• 2008

In order to evaluate a solenoid actuator's reliability, the following three-step approach was used: (1) we analyzed the cause and effect of major failures through FMEA and FTA, decided the main test items through 2-stage QFD; (2) after a performance test was carried out, five-sampled data were collected from the it; finally, we decided the reliability parameters for the industrial solenoid actuator. The reliability parameters, such as the shape parameter(${\beta}$), the scale parameter(${\theta}$), etc., were analyzed inductively by the use of MINITAP and the Weibull probability model which has been used practically in the study of the reliability.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1807-1808
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• 2008

When it is used for autonomous mobile robots by using dead-reckoning system, odometry system with encorder is the simplest method as well as well-known in the industry. However, odometry system is reflected slide, friction and mechanical errors of wheels when operating the position estimation. And also in order to minimize errors of direction angle which is the most important factor that it is designed the controller in controlling kinematics and quadratic curve, PID that came into the values of sensor fusion with encorder and gyroscope sensor. After designing, the autonomous mobile robot is producted practically and inspected how it works.

• Korean Journal of English Language and Linguistics
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• v.1 no.3
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• pp.437-456
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• 2001

This paper raises a question on the theoretical background behind the English education at the elementary school level. The Critical Period Hypothesis (CPH), supporting the common belief of the earlier the better in foreign language learning, which has promoted the strong trend toward teaching English in Korean elementary schools, is analyzed to determine whether it provides a comprehensible picture to explain age-related factors and whether it is a valid hypothesis which can be applicable in an EFL situation such as Korea. This paper concludes that CPH itself is still considered as an impending hypothesis full of unresolved issues and that the present educational situation of Korean elementary schools is rather far from the environment in which the ideas of CPH could practically apply, and thus it may be desirable to find alternative theoretical backgrounds from which the educational programs can be developed and further expanded.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2000.11a
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• pp.169-172
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• 2000

This paper describes a Push-Pull type high frequency resonant inverter composed of consolidation of boost converter circuit and resonant inverter circuit. By using a boost converter circuit, the proposed inverter can obtain a twice input voltage of resonant circuit and reduce a secondary turn ratios. also, by using both switching device of boost-converter and resonant circuit, the number of switching device can be reduced by half, the analysis of the proposed circuit was generally described by using normalized parameter and operating characteristics have been evaluated as to switching frequency and parameters. In the future, this proposed inverter shows that is can be practically used as a power source system for the lighting equipment of discharge lamp, induction heating applications.

• Journal of the Korean Society of Safety
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• v.10 no.1
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• pp.20-27
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• 1995

There are many methods to move or reduce the static electricity which often causes disasters in Industry, etc. The methods may Include grounding of a potentially-charged body, use of antistatic materials, humidification of an atmosphere, use of static electricity eliminators. Among those methods, the one utilizing antistatic materials is widely used in the industrial fields due to its effectiveness and inexpectiveness. In Korea, safety regulations and technical standards are not sufficient for applying to industrial fields as electrostatic disaster prevention measures due to the shortage of practically verified and reliable data. The propose of this paper is to examine the electrostatic characteristics of the antistatic materials and non-antistatic ordinary materials under the various conditions of different temperature and humidity.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2000.11a
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• pp.173-178
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• 2000

The time sharing type high frequency inverter using serial-parallel resonant to give VVVF function in the inverter used as power source of induction heating at high frequency is presented in this paper. This proposed inverter can reduce distribution of the switching current because of using the current of serial resonant circuit to the input current of the parallel one. The analysis of the proposed circuit is generally described by using the normalized parameters. Also, according to the calculated characteristics value, a method of the circuit design and operating characteristics of the inverter is proposed. In addition, this paper proves the validity of theoretical analysis through Simulation. This proposed inverter show that it can be practically used in future as power source system for induction heating application, DC-DC converter etc.

• Journal of the Korean Home Economics Association
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• v.36 no.4
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• pp.109-120
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• 1998

The Purpose of this research was to introduce communication training program for positive parent-adolescent relation into home economics education curriculum. The research applied the program named "Making the desirable world 2" which was revised by K.E.T.I(Korea Effectiveness Training Institute). This program was given two hours a week during 8 weeks. The subject of this study was 24 students, divided into two groups, the experimental and the control group. This research supposed that parent-adolescent communication and self-esteem in the experimental group would significantly increase by group training program. The results of this research are as follows. First, parent-adolescent communication in the experimental group was significantly increased by the group training program. Second, self-esteem in the experimental group was significantly increased by the group training program. For home economics education as a practical subject matter, promoting qualitative maturity of students' family life, this study aimed both at enhancing communication for positive relation of parent-adolescent by group training and implementing home economics education curriculum practically.

• Advances in materials Research
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• v.6 no.2
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• pp.185-220
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• 2017

Merits, attributes and challenges associated with the application of analytical modeling in electronics and photonics materials science are addressed, based mostly on the author's research during his tenure with Bell Labs, University-of-California, Portland State University, and small business innovative research (SBIR) ERS Co., USA. The emphasis is on practically important, yet often paradoxical, i.e., intuitively non-obvious, material behaviors. It is concluded that when material reliability is crucial, ability to effectively quantify it is imperative, and that analytical modeling is the most suitable, although never straightforward, technique to understand, explain and quantify material behaviors, especially in extreme, extraordinary and paradoxical situations.

• Structural Engineering and Mechanics
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• v.65 no.4
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• pp.477-490
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• 2018

Reinforced concrete (RC) columns, as the primary load-bearing structural components in buildings, may need to be strengthened due to material deteriorations, changes in usage, new building codes or new design requirements. The use of post compressed plates (PCP) to strengthen existing RC columns has been proven experimentally and practically to be effective in solving stress-lagging effects between the original column and the new strengthening jacket caused by the pre-existing loads. This paper presents a comprehensive summary and review of PCP strengthening techniques to strengthen preloaded RC columns. The failure mode, deformability, and ductility of the strengthened RC columns are reviewed.