• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.11
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• pp.1752-1758
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• 1989

For many different types of apertures the diffraction phenomenon on the electromagnetic wave is analyzed by unsing Kirchhoff and Fresnel's diffraction theory. The signal intensity in variation of aperture's parameters is numerically calculated by a computer. To obtain the experimental data many types of apertures were made on an acryl board on which a special materical Elecoat was painted for preventing some reflections on the board surface and transmissions through it. Two Yagi antennas were used for a transmitting and receiving antenna and the frequency was 820MHz. The theoretichal values agreed reasonably with experimental data and these results will be used for a system design in the mobile communication between many buildings in the middle of a city.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.03b
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• pp.24-24
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• 2010

In this paper, we analyzed the frequency spectrum of electromagnetic waves which is generated by series arc discharges to develop a condition monitoring technique in a closed-distribution board. We fabricated an arc generator specified in UL1699 to simulate series arc discharge. The experiment was carried out in an electromagnetic shielding room, and the measurement system consists of a Ultra Log Antenna and a EMI Test Receiver. The results showed that the frequency spectrum during series arc discharges was distributed in ranges of 30~500 [MHz], and the peak values were existed at 40 [Mhz] and 80 [MHz].

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2011.10a
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• pp.440-443
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• 2011

This paper aims to compose a new LED lighting control board in the LED lighting environment This LED lighting control board is designed to adjust the brightness of LED lighting depending on the change of surrounding brightness, and it is also designed to control the brightness by using ATmega128, which is an 8bit micro-controller, The PWM wave form likely to output into the LED driver is determined by the ADC value input through ADC.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.10a
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• pp.890-893
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• 2014

In this paper, we present a signal processing algorithm for a marine radar system, in which the evaluation of probability of collision as well as target detection and tracking are performed. Moreover, the digital signal processor that implements the algorithm is proposed. As simulation environment, a mechanically scanning antenna utilizing FMCW signal is used, conducting the beamforming operation with 1 degrees intervals. Test board consists of DSP chips and FPGA, which enable the implemented system to operate in real-time.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.12 no.4_1
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• pp.137-150
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• 1992

A complete solution, exact to second-order, for wave motion forced by a hinged-wavemaker of variable-draft is presented. A solution for a piston type wavemaker is also obtained as a special case of a hinged-wavemaker. The laboratory waves generated by a plane wave board are shown to be composed of two components; viz., a Stokes second-order wave and a second-harnomic free wave which travels at a different speed. The amplitude of the second-harmonic free wave is relatively large in shallow water and decreases to less than 10% of the amplitude of the primary wave in deep water. Wavemakers with relatively deeper draft (i.e., hinged near the bottom) generate the free waves of smaller amplitude in shallow and intermediate water depths than the wavemakers with shallow draft. However, the opposite is predicted by theory in deep water.

• Journal of Korea Society of Industrial Information Systems
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• v.20 no.6
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• pp.79-90
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• 2015

Since the late 1990s, the Korea wave has been very big issue among Asian nations. It has been increased in some regions including Russia, East Europe, South America but it has been decreased in some regions including Southeast Asia, Japan and China. The stream of Korea wave has been changed until now. We need a study considering on the time period of Korea wave. So this paper shows several implications from some changes by each time period of Korea wave for Southeast Asia cultural regions. In order to achieve objectives of the paper, we collected and classified 2511 requirements from bulletin board systems and e-mails. It shows how to improve e-service quality and to enhance nation brand utilizing types of requirements of Southeast Asia cultural regions and by the time period of Korea wave using QFD methodology. These implications are applied to design a tourism website for Southeast Asia cultural region.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.294-296
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• 1988

The tomographic imaging that employs ultrasonic echos has achieved outstanding advances in recent years, and today, ultrasonic diagnostic equipment has become the tool that is absolutely indispensible for clinical operations. Meanwhile, the feasility of measuring blood flow in the heart and vessels by the use of Doppler effect in ultrasonic waves is a well known fact. With respect to the method of blood flow measurment, there are two kinds which employ continous wave and pulse wave doppler system. In this paper, we describe the measurment of Blood flow-turbulence using general purpose Digital Signal Processing Board which had been implemented for the purpose of real-time spectrum analyser. Blood flow-turbulence means the blood-flow behavior. And it's value proportional to the spectrum variance. Therefore mean frequency of blood signal and variance provide useful diagnostic information. We have applied to the major arteries and vein, obtained the information about the time dependent blood-flow behavior.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.11a
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• pp.265-269
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• 1996

In this paper, electric field interference was analyzed in the Printed Circuit Board to restrain the elcctromagnetic wave using Boundary Element Method and Finite Element Method. First, charge density distribution was simulated using Boundary Element Method and the characteristic impedance was caculated to restrain the reflex wave, and mutual capacitance was caculated in the multi-strip line PCB. Finally, electric field was simulated in the variable patterns using Finite Element Method. As a result, the optimal structure and characteristics of strip line was obtained and the imformations about the optimal design pattern could be obtained with the analysing the feild distribution.

• Journal of Sensor Science and Technology
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• v.24 no.5
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• pp.299-305
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• 2015

Since the natural disasters such as floods, droughts, heat wave and cold wave are increasing, the need for risk management is necessary to minimize the damage with utilizing IT technology. Also, the monitoring services of disaster response type have been developed and applied. Recently, the open source hardware based on the signal of the sensor, or the monitoring studies have been carried. In this paper, by analyzing a low-cost open source hardware platform such as Beagle board, we examine the utilization of the hardware-based module for sensor monitoring.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.1
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• pp.76-83
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• 2011

The IEEE WAVE-based communication systems do not provide handover services since most of the application layer messages of a small amount containing text data that are related to safe driving. Multimedia data service such as web pages and CCTV video clips, however, require a seamless handover for continuation of a session via multiple RSUs. In this paper, we propose a new proactive handover protocol based on IEEE WAVE. According to the proposed handover protocol, the OBU notifies the old RSU of its departure from the coverage such that the old RSU forwards to the new RSU the data heading towards the OBU to be cached for the further delivery upon its entry into the new RSU's coverage. The simulation results are presented which shows the performance of the proposed protocol in terms of throughput, delivery ratio and handover delay.