• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2018.05a
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• pp.175-177
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• 2018

항해용 X-band 레이더는 물표탐지를 통한 안전한 항해를 목적으로 널리 사용되고 있다. 해당 목적을 위해서는 노이즈로 간주되는 해면반사파(sea clutter)신호는 제거하여 사용하지만, 본 연구에서는 노이즈로 간주되는 해면반사파 신호를 활용하여 파랑에 대한 정보(파고, 파주기, 파향 등)를 파악하는데 활용하였다. 레이더에서 방출되는 전자기파는 펄스의 길이에 의해 탐지할 수 있는 영역이 제한되어 있다. 펄스의 길이가 짧을수록 짧은 주기의 파랑을 계측할 수 있다는 장점이 있지만, 거리의 제약으로 인하여 대형선박의 실 운항시에는 활용하기 어려운 현실적인 딜레마가 있다. 본 연구에서는 삼성중공업, 오션알앤디가 개발한 WaveFinder 시스템을 이용하여 기존 short pulse 모드 뿐만아니라 midium pulse 에서의 활용 가능성을 실제 시운전을 통해 확인하였다.

• Proceedings of the KIEE Conference
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• 1994.11a
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• pp.274-277
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• 1994

This paper describes a very fast rising high voltage pulse generation for studying surge phinomenon and prebreakdown of liquid dielectric by appling the traveling wave theory of the distributed circuit. This very fast rising high voltage pulse generator consists of a charging coaxial cable, a discharging switch, and a terminating resistance. As results, the rising time of pulses are about 31(nsec), which is very fast, and its duration is 950[nsec] when using 200[m] coaxial cable. The length of the coaxial cable and changing voltage can regulate the duration and the amplitude or the polarity of the pulse. When terminated the resistance, capacitor and inductor, the measured waveform corresponds with simulated waveform.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.539-542
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• 1998

In this paper, we devised pulse rate diagnosis database system for provide basic index of Cold-Hot diagnosis. The system consist of database part and pulse rate detection part that for detection pulse wave, respiration and ECG. The database is constructed windows95 platform using DAO(Data Access Object). Search algorithm used ISAM algorithm. The database consist of patient information and medical report for a subject and detected biological signals.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2022.11a
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• pp.183-184
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• 2022

In this study, harmonics of 100 kHz ultrasonic pulse transmitted through concrete exposed to high temperature were evaluated. Concrete exposed to high temperatures deteriorates its mechanical properties. In ultrasonic pulse, the fundamental wave was attenuated by the deterioration of the concrete. In addition, it was possible to confirm the occurrence of harmonics. It is thought that the fundamental and harmonics of ultrasonic pulse greatly affected by the internal structure of concrete.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.11a
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• pp.812-819
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• 2007

Acoustic Target Strength (TS) is a major parameter of the active sonar equation, which indicates the ratio of the radiated intensity from the source to the re-radiated intensity by a target. This research provides the time pattern of TS in time domain, which is applicable to pulse modulated acoustic pressure field. If the time pattern of TS is predicted by using TS equation in frequency domain, it takes long time and difficult since time function pulsed acoustic wave may be decomposed into their frequency domain components. But TS equation in time domain has a convenience. If the expression for pulsed acoustic field has been obtained, the problem can be solved. Furthermore this paper introduces about mathematical equivalence quantities between EM wave and Acoustic Wave.

• Current Optics and Photonics
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• v.1 no.5
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• pp.525-528
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• 2017

High-energy, high-power, quasi-continuous wave (QCW) operation of double-clad Yb fiber lasers incorporating an incoherent signal combiner is reported. We constructed four efficient, high-power Yb fiber lasers, each of which produced rectangular pulses at 1080 nm with a pulse energy greater than 15 J, and a pulse duration of 10 ms at a repetition rate of 10 Hz, corresponding to an average power of over 150 W and a peak power of over 1.5 kW for ~200 W of incident pump power at 915 nm. These laser outputs were combined by a homemade incoherent fiber signal combiner with low loss, yielding a maximum peak power of ~6.0 kW in a beam with $M^2{\approx}12.5$. The detailed laser characteristics and prospects for further power scaling in QCW operation are discussed.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.6
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• pp.591-598
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• 2006

The research was tried to investigate the hydrogen generation from water by the pulsed power plasma process. Hydrogen was generated by way of the electrical pulse power discharge process with the ultrasonic wave. The yield on the hydrogen generation was also studied with and without operating the ultrasonic generator, in which the applied high voltage was varied from 10 kV to 15 kV. Nitrogen and argon gases were used as working gases. As the results, the generation yield using the pure nitrogen gas is better than argon and mixed gases such as argon and nitrogen. Hydrogen concentration are significantly increased when the ultrasonic generator was operated with the electrical discharge simultaneously. It is increased with increasing the applied ultrasonic level as well.

• Proceedings of the Membrane Society of Korea Conference
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• 2001.05a
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• pp.128-131
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• 2001

• Proceedings of the KWS Conference
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• 2003.11a
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• pp.129-131
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• 2003

• Proceedings of the KIEE Conference
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• 1985.07a
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• pp.220-223
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• 1985