• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.8
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• pp.162-167
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• 2013

X-ray or ${\gamma}$-ray spectroscopy systems are widely used for analyzing material characteristics. Pile-up pulses are very often encountered for several reasons in XRF systems. Thus, it is necessary to reject or recover pile-up pulses to accurately analyze the material under test. In this paper, a pile up pulse rejection and recovery method is presented for XRF systems using trapezoidal pulse shaping of the input signals. Since the proposed method is based on the trapezoidal pulse shaping method widely-used in XRF systems, only two counters and a few registers are needed to implement the additional function of pile-up pulse rejection and recovery. Consequently, the proposed system is much simpler than conventional pulse reconstruction systems. It is shown that the proposed method can detect and reject pile-up pulses exactly. It is also shown that the pile-up pulses can be recovered if some conditions are satisfied.

• Journal of Radiation Protection and Research
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• v.31 no.4
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• pp.173-179
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• 2006

The Monte Carlo simulation code CEARPPU has been developed and updated to provide pulse pile-up correction spectra for high counting rate cases. For neutron activation analysis, CEARPPU correction spectra were used in library least-squares method to give better isotopic activity results than the convention library least-squares fitting with uncorrected spectra.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.5
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• pp.112-117
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• 2004

In this paper, in order to obtain the detailed information about lightning electromagnetic pulses, the electromagnetic pulses radiated from intracloud discharges were measured, and their characteristics and waveform parameters were analyzed statistically. The electromagnetic pulses produced by intracloud discharges are distinctly different with those by lightning return strokes. The zero-crossing times and the full pulse widths of the large bipolar electromagnetic pulses are gradually decreased as the stroke proceeds. Also, the electromagnetic pulses tend to be bipolar, with narrow and fast leader pulses superimposed on the initial half cycle. The mean numbers of leader pulses superimposed on the initial half cycle were 1.61$\pm$0.74 and 1.75$\pm$0.73 for the positive and negative polarities, respectively.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.10
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• pp.141-149
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• 2008

Because aluminum has a lighter weight and higher strength than iron, it is frequently used in the transportation industry for the purpose of reducing the weight of a chassis, and thereby increasing fuel efficiency. However, there are some difficulties with arc welding aluminum due to its lower melting point, high thermal conductivity and oxidation coating on its surface. This study proposed using superposition ac pulse MIG arc welding, which has been improved from the pulse waveform of conventional MIG welding. A MIG arc welding power source was developed to test the effectiveness of this method.

• Journal of Korea Water Resources Association
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• v.34 no.6
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• pp.577-586
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• 2001

This study proposes a theoretical methodology for deriving a rainfall intensity-duration- frequency (I-D-F) curve using a simple rectangular pulses Poisson process model. As the I-D-F curve derived by considering the model structure is dependent on the rainfall model parameters estimated using the observed first and second order statistics, it becomes less sensitive to the unusual rainfall events than that derided using the annual maxima rainfall series. This study has been applied to the rainfall data at Seoul and Inchon stations to check its applicability by comparing the two I-D-F carves from the model and the data. The results obtained are as followed. (1) As the duration becomes longer, the overlap probability increases significantly. However, its contribution to the rainfall intensity decreases a little. (2) When considering the overlap of each rainfall event, especially for large duration and return period, we could see obvious increases of rainfall intensity. This result is normal as the rainfall intensity is calculated by considering both the overlap probability and return period. Also, the overlap effect for Seoul station is fecund much higher than that for Inchon station, which is mainly due to the different overlap probabilities calculated using different rainfall model parameter sets. (3) As the rectangular pulses Poisson processes model used in this study cannot consider the clustering characteristics of rainfall, the derived I-D-F curves show less rainfall intensities than those from the annual maxima series. However, overall pattern of both I-D-F curves are found very similar, and the difference is believed to be overcome by use of a rainfall model with the clustering consideration.

• Journal of the Korea Computer Industry Society
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• v.2 no.4
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• pp.565-572
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• 2001

At the most recent years, laser medical instruments, laser applications and laser nuclear fusion need strong visible light and ultraviolet rays. Nonlinear optical devices, such as harmonic generators and parametric oscillators, provide a means of extending the frequency range of available laser sources. Frequency conversion is a useful technique for extending the utility of high-power lasers. It utilizes the nonlinear optical response of an optical medium in intense radiation fields to generate new frequencies. These progresses have been used to generate high-power radiation in all spectral regions, from the ultraviolet to the far infrared. Optical parametric oscillators and amplifiers generate two waves of lower frequency They are capable of generating a range of wavelengths from a single frequency source, in some cases spanning the entire visible and near infrared regions. Consequently, in order to obtain the green light, the pulsed Nd:YAG laser using multiple-mesh PFN(Pulsed Forming Network) method with Nonlinear optical device was adopted. We compared the current pulseshapes with the laser output energy, and conversion efficiency.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1320-1321
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• 2008

펄스파워기술은 저장된 전자에너지를 시공간적으로 압축 중첩하여 극히 짧은 시간안에 대전력을 발생시켜 좁은 공간에 에너지를 집중 공급하는 기술이다. 여기에는 에너지를 저장하는 충전장치에 대한 기술과, 빠른 시간에 에너지를 방출하는 스위칭기술, 파형을 성형하는 펄스포밍 네트워크 기술등을 포함하며, 이를 이용한 응용기술로 플라즈마건, 이온빔 가속장치, 펄스성형용접, 수처리 발라스트, 파암장비, 코일건, 레일건 등이 있으며, 이 응용분야에 오래전부터 이용되어 왔다. 이러한 분야에 적용되는 펄스전원장치는 이동성이 용이해야 하고, 부피 또한 작은 구조를 가져야 한다. 본 논문은 고집적화 펄스전원장치의 츠로토 타입 설계, 제작, 실험에 관한 논문으로 그 중 펄스성형을 이뤄내는 인덕터에 대한 성능 실험 결과를 위주로 한다.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2009.05a
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• pp.113-116
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• 2009

Full-HD 구현이 가능하고, 패널 전체에 priming 방전을 동시에 일으킬 수 있는 새로운 고속구동법인 표시기간 중첩 프라이밍 방전 기술의 초기화 펄스 특성을 연구하였다. ramp 펄스를 이용한 약방전으로 초기화 방전을 일으킬 경우 램프 기울기가 작아질 수록 불필요한 광을 줄일 수 있어 명암비가 높아지므로 프라이밍 펄스폭을 증가시키는 것은 매우 중요한 일이다. 본 논문에서는 ramp의 기울기를 변화시키며 안정적인 표시방전이 유지되는 ramp 펄스폭을 실험을 통해 확인하였고, 그 결과 $200{\mu}s$(ramp 기울기 $1.45V/{\mu}s$)의 ramp 펄스폭에서도 표시방전이 안정적으로 발생한다는 것을 알았다.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.3
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• pp.177-185
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• 2000

In this study, the characteristics of various electricity and high resistivity ash collection were measured at superimposed nanosecond pulse energization. The pulse was generated through the hydrogen thyratron. Superimposed pulse was nanosecond duration pulse that had fast pulse rising time 100[ns], short pulse width 500∼850[ns] and pulse fall time 400∼750[ns]. The results of this study are summarized as followings; Frist, compared with the DC ESP(electrostatic precipitator), superimposed pulse ESP could induce higher peak voltage, and had the about 30[%] reduction of ESP collection area and 50∼80[%] reduction of power consumption. showing the same efficiency. Second, enhancement factor H had 1.9∼3.6 with the increase of migration velocity.

• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.327-328
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• 2013

대용량 전력변환기에서 필터로 사용되는 인덕터의 특성은 전력변환 효율 및 전력 품질에 결정적인 역할을 하는 매우 중요한 수동소자이다. 따라서 PWM 방식의 대용량 전력변환장치에서 특성이 좋은 인덕터를 사용하는 것은 매우 중요하다. 이러한 인덕터의 특성을 분석하기 위해서는 인덕터의 자기적 포화를 관찰하기 위한 펄스전압에 의한 전류특성을 분석하는 방식과 DC 중첩 특성을 사용하여 전류리플에 따른 인덕터의 특성 분석 방식을 사용한다. 따라서 본 연구에서는 이러한 특성을 분석하기 위해서 펄스전압 및 DC 중첩을 발생할 수 있는 장비를 제작하고 이를 분석할 수 있는 장치를 개발하였다.