• Journal of the Optical Society of Korea
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• v.18 no.4
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• pp.382-387
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• 2014

An all-reflective, simple noncollinear second harmonic (SH) autocorrelator is described for monitoring the shot-to-shot behavior of ultrashort high-power laser pulses. Two mirrors are used for the dispersion-free splitting of a pulse into two halves. One of the mirrors is able to adjust the delay time and angle between two halves of the laser pulse in a nonlinear crystal. We present the possibility of real-time measurement of the pulse duration, peak intensity (or energy), and the pointing jitters of a laser pulse, by analyzing the spatial profile of the SH autocorrelation signal measured by a CCD camera. The measurement of the shot-to-shot variation of those parameters will be important for the detailed characterization of laser accelerated electrons or protons.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.373-375
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• 1997

In this study, we designed multiple mesh circuit consisting of 3-6 meshes and pulse superposition one consisting of a 3 mesh, and fabricated the electrical power supply and the single elliptical resonator. We developed the two pulse superposition technique forming the step pulse shapes of pulsed Nd:YAG laser with single shot multivibrator and 2 SCRs. Laser beam generated by multiple mesh circuit and superposition one respectively irradiated target surface to analyze process state of surface with spark and vapor. And it was obtained experimental results that all superposition meshes had common points which the best efficiency was obtained at delay time 0[${\mu}s$], followed by, no superposition and obtained at delay time 250[${\mu}s$].

• Proceedings of the KIEE Conference
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• 1997.07e
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• pp.1864-1866
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• 1997

In this study, we designed the pulse superposition network consisting of a six-mesh and a three-mesh network, and fabricated the electrical power supply and the single elliptical resonator. We have developed a tec.bnique forming the step-pulse shape of pulsed Nd:YAG laser by using one shot multivibrater and have studied on the effect of two pulses superposition for the output and efficiency improvement of pulsed Nd:YAG laser by superposing a sinusoidal pulse on a main pulse.

• Laser Solutions
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• v.17 no.3
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• pp.15-18
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• 2014

In this paper, we studied a machining method using a diffractive beam splitter (DBS) and multi- pulse repeated radiation for breathable film. We fabricated micro-grooves on polypropylene (PP) films using multi-pulse radiation and one-shot radiation (radiating pulses at once) and a DBS. In the result, width and depth of the PP film using multi-pulse repeated radiation were more precisely controllable. Therefore, this method can be applicable to in manufacturing breathable film precisely at a high speed.

• Journal of IKEEE
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• v.21 no.4
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• pp.375-380
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• 2017

A differential current-to-time interval converter is presented for current mode sensors. It consists of a ramp voltage generator, a current mode sensor, a reference current source, two current-tunable Schmitt triggers, a one-shot multivibrator, and two logic gates. The design principle is to apply a ramp voltage to each input of the two current-tunable Schmitt triggers whose threshold voltages are proportional to the drain current values of the current mode sensors. A proposed circuit converts a current change in the ISFET biosensor into its equivalent pulse width change. A prototype circuit built using TSMC 0.18 nm CMOS process exhibit a conversion sensitivity amounting to $726.9{\mu}s/pH$ over pH variation range of 2-12 and a linearity error less than ${\pm}0.05%$.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.5
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• pp.1119-1124
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• 2011

The operation of current conveyor circuit is similar to an operational amplifier and a current conveyor circuit has the characteristics such as good linearity and stability. In this paper, a frequency-to-voltage converter circuit is designed by using a current conveyor circuit. The supply voltage is 5volts and the designed circuit is simulated by HSPICE. The range of the input frequency is from 4kHz to 200kHz. From the simulation results the error of the output voltages is less than from -1.3% to +2.5% compared to the calculated values.

• Proceedings of the Korea Information Processing Society Conference
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• 2012.11a
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• pp.478-481
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• 2012

구조 광을 이용한 3차원 정보 획득 방법으로는 레이저 스캐닝 기술과 다양한 패턴을 투영 기술, 그리고 컬러 패턴을 이용한 기술 등이 존재한다. 여러 장의 이진 패턴을 사용하는 경우, 여러 장의 패턴영상을 영속적으로 투영해야 하므로 움직이는 물체가 있는 경우 3차원 복원이 불가능한 단점을 지니고 있으며, 이를 보안하기 위해 그레이 혹은 컬러 패턴을 사용하여 패턴의 영상수를 줄일 수는 있으나, 이 경우엔 깊이 맵의 해상도의 한계와 컬러 오브젝트로 인한 에러 발생 문제가 발생 한다. 본 논문에서는 PWM(Pulse Width Modulation)방식을 이용하여 이진 패턴과 컬러 패턴의 문제점을 보완할 수 있게 단일 영상, 즉 "One-Shot"으로 스캐닝 하는 알고리즘을 제시한다.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.4
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• pp.982-989
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• 2004

The following is the conclusion drawn from a review on the clinical cases cured by Jaeumkangwha-tang in perspective of Hyungsang medicine. Jaeumkangwha-tang originated from the modified Jibaiksamul-tang in 'Manbyunghuichun(萬病回春)' and applied to the diseases induced by flaming fire due to deficiency of Yin. In 'Donguibogam', there are two kinds of Jaeumkangwha-tang. One in the chapter of kidney is mainly prescribed to replenish the Jung of kidney and applicable to the cases with configuration and symptom of kidney along with fire. The other one in the chapter of fire is applied to the symptoms of flaming fire due to deficiency of Yin. The characteristics of the patients treated by Jaeumkangwha-tang from the viewpoint of Hyungsang medicine can be classified as follows : ① configuration: Dam type, Shin type, inverted triangular type(:天垂象), bird type, round eyes, thin lips, slender waist, thin leg, pretty face, sparkling eyes, prominent upper lip and upward eyes and nose. ② color : dark red complexion, red cheek bone, red lips and red glabella. ③ pulse : fine and fast pulse and pulsation on the Chuk(尺) in man and so forth. ④ symptoms: agility, talkativeness, pimpled face, crooked back, weakness to the heat of summer, light eating, timidity, blood-shot eyes, night sweat, cough, abundant phlegm, hemoptysis, bloody spittle, enervation, emaciation, back pain, flaccidity of lower limbs, involuntary emission, nocturnal emission, heat sensation in the chest palms and soles, anger, flush on cheek bone, red lips and dry mouth, reddish tongue, stiff excrement, scanty yellow urine, etc.

• Journal of Biomedical Engineering Research
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• v.17 no.1
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• pp.19-24
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• 1996

The purpose of this paper is to design high-order (or radial) surface gradient coil (SGC), which can provide multi-dimensional spatial selection. Although the spatial Selection with High-Order gradienT (SHOT) can provide a 2-D selection with only one selective RF pulse, the high-order gradient pro- duced by conventional cylindrical-shape coils has not been clinically useful due to the large selection size caused by the limited radial gradient intensity. However, by using the proposed high-order SGCs located near the imaging region, the size of volume selection can be reduced to a clinically useflll size of 1-2 cm in diameter by applying stronger radial gradient field with much less gradient driving power. So far radial SGCs have been designed by using the field component method and may cause distortion in the selection shapes. In this paper, by using the target field approach for the coil design, selected volumes became almost circular. A 40 cm-by-40 cm $z^2$_surface gradient coil has been designed and implemented by using the target field approach. Phantom and volunteer studies have been performed Experimental results using spatially localized MRI show good agreement to the theoretically predicted behavior.

• Proceedings of the KOSOMBE Conference
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• v.1994 no.12
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• pp.43-46
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• 1994

A new spatial localization technique using high-order surface gradient coil (SGC) is proposed. Although the Spatial Selection with High-Order gradient (SHOT) can provide a 2-D selection with only one selective RF pulse, the high-order gradient produced by cylindrical-shape coils has not been clinically useful for clinical systems due to the large minimum selection size caused by the limited radial gradient intensity. However, by using the proposed high-order SGCs located near the imaging region, the size of volume selection can be reduced to a clinically useful 1-4 cm in diameter by applying stronger radial gradient with much less gradient driving power. A 40 cm-by-40 cm $r^{2}$ SGC has been designed and constructed, and phantom and volunteer studies have been performed. Experimental results using spatially localized MRI show good agreement to the theoretically predicted behavior.