• Nuclear Engineering and Technology
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• v.55 no.9
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• pp.3326-3333
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• 2023

The results of the analysis of a mathematical modeling for the IBR-2M pulsed reactor dynamics for a transition from a power pulse repetition frequency of 5 Hz-10 Hz are presented. The change in the amplitude response of the reactor for variable pulse delayed neutron fraction was studied. We used a set of power feedback parameters determined experimentally in 2021 at an energy output of 1820 MW·day. At a pulse repetition frequency of 10 Hz, the amplitude of pulse energy oscillations significantly depends on the value of the delayed neutron fraction in pulse β_p. Depending on β_p both suppression and amplification of reactor power fluctuations in the frequency ranges of 0.05-0.20 and 1.25-5.00 Hz can be realized.

• Journal of Sasang Constitutional Medicine
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• v.35 no.4
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• pp.1-9
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• 2023

Objectives This study is designed to examine the relationship between healthy state (完實無病) of Sasang constitution and pulse wave (脈波). Methods The subjects were 100 patients who were diagnosed with Sasang constitution and underwent pulse analyzer test. The status of urination, defecation, perspiration, and digestion was classified as good, intermediate, and poor. The power, depth, speed, and roughness of pulse waves (脈波) were analyzed. Results Patients with poor digestion had relatively powerless pulse wave (無力脈). Soeumin patients had a higher rate of poor digestion compared to other constitutions. Soyangin patients had a higher rate of poor perspiration compared to other constitutions. Soyangin with poor defecation had relatively choppy pulse wave (澁脈), and poor perspiraton had relatively slippery (滑脈). Soeumin patients with poor digestion had relatively powerless pulse wave (無力脈). Conclusions The pulse wave of poor healthy state (完實無病) is an expression of a pathological syndromes (病證) caused by lack of or damage to healthy energy (保命之主). It was concluded that the pulse analyzer can be used to evaluate healthy state (完實無病).

• Laser Solutions
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• v.13 no.4
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• pp.7-13
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• 2010

Today, the most common process for generating Through Silicon Vias (TSVs) for 3D ICs is Deep Reactive Ion Etching (DRIE), which allows for high aspect ratio blind holes with low surface roughness. However, the DRIE process requires a vacuum environment and the use of expensive masks. The advantage of using lasers for TSV drilling is the higher flexibility they allow during manufacturing, because neither vacuum nor lithography or masks arc required and because lasers can be applied even to metal and to dielectric layers other than silicon. However, conventional nanosecond lasers have the disadvantage of causing heat affection around the target area. By contrast, the use of a picosecond laser enables the precise generation of TSVs with less heat affected zone. In this study, we conducted a comparison of thermalization effects around laser-drilled holes when using a picosecond laser set for a high pulse energy range and a low pulse energy range. Notably, the low pulse energy picosecond laser process reduced the experimentally recast layer, surface debris and melts around the hole better than the high pulse energy process.

• Proceedings of the KIEE Conference
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• 1987.07a
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• pp.768-770
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• 1987

• Korean Journal of Oriental Medicine
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• v.18 no.2
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• pp.139-149
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• 2012

Objectives : This is the study to understand of the pulse wave factor according to BMI and period of sterility on female, and to confirm the relationship of pulse wave factor among left and right inch, bar and cubit. Methods : The Questions and measurement of the pulse wave were operated with subjects(76 sterile females using on public health center). The measurement of the pulse wave was operated in 6 part of left and right inch, bar and cubit. The pulse wave was prior measured in part of left bar (i.e. interior pulsation part of radial process styloides in left hand), and next was measured in part of left inch and bar. And the pulse wave was operated samely in part of right inch, bar and cubit. Results : The results were as follows. The pulse energy of 6 part of left and right inch, bar and cubit was showed statistical significance and decreased in order of left inch, right inch, left cubit, right cubit, left inch, right bar. The left and right inch and cubit were showed numerical value of normal range, but left and right bar were showed lower pulse eneregy than normal range. Also left and right cubit were showed lower than left and right inch, and higher than left and right bar. In BMI, The pulse energy of left and right inch, cubit and the average of right hand was not showed statistical significance in the range of low-weight, normal, over-weight and obesity. But in the left and right bar and the average of left hand, the pulse energy of over-weight and obesity group were showed significantly higher than low-weight group. And the pulse wave factor was divided the pattern of h1 showing high numerical value in inch (Ap, As, Aw) and the pattern of Wm showing high numerical value in bar and cubit (RAI, Ad) Conclusions : The low pulse energy of bar was significant observation on the setting of oriental medical diagnostic index on sterilitas. Also, in the numerical value pattern of diverse pulse wave factor, it was divided the pattern of high numerical value in inch and the pattern of high numerical value in bar and cubit. On this, we think that the studies need in the future.

• Progress in Superconductivity and Cryogenics
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• v.12 no.2
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• pp.29-33
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• 2010

The experimental results of the 2 stage Gifford-McMahon(GM) type pulse tube refrigerator (PTR) or cryopump are presented in this paper. The objectives of his study are to develop design technology of the integral type 2 stage PTR which rotary valve is directly connected to he hot end of the regenerator and acquire its improved performance. Design of the 2 stage PTR is conducted by FZKPTR(Forschungs Zentrum Karlsruhe Pulse Tube Refrigerator) program for the design of pulse tube refrigerators. The fabricated PTR has U-type configuration and incorporates orifice valve, double-inlet valve and reservoir as phase control mechanism. Rotary valve is used to make pulsating pressure and is directly connected to inlet of $1^{st}$ stage regenerator. From experiments, cooling performance map and pressure waveform at each point were measured for different operating frequencies. Experimental results show the best cooling performance with 2 Hz operation in spite of small pressure amplitude. The lowest temperatures of the 2 stage PTR were 16.9 K at the second stage and 58.0 K at the first stage. The cooling capacities achieved were 14.4 W at 79 K, the first stage and 3.6 W at 29 K, the second stage.

• Progress in Superconductivity and Cryogenics
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• v.13 no.4
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• pp.30-35
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• 2011

This paper describes experimental study and performance improvement of 2 stage Gifford-McMahon (G-M) type pulse tube cryocooler for cryopump. The objective of this study is to improve the efficiency of 2 stage pulse tube cryocooler for substituting 2 stage G-M cryocooler used in cryopump. The target cooling capacities are 5 W at 20 K and 35 W at 80 K for the $1^{st}$ and the $2^{nd}$ stage, respectively. These values are good cooling capacities for vacuum level in medium size ICP 200 cryopump. Design of the 2 stage pulse tube cryocooler is conducted by FZKPTR(Forschungs Zentrum Karlsruhe Pulse Tube Refrigerator) program. In order to improve the performance of 2 stage pulse tube cryocooler, U-type pulse tube cryocooler is fabricated and connecting tubes are minimized for reducing dead volumes and pressure losses. Also, to get larger capacities, orifice valves and double inlet valves are optimized and the compressor of 6 kW is used. On the latest unit, the lowest temperatures of 2 stage pulse tube cryocooler are 42 K ($1^{st}$ stage) and 8.3 K ($2^{nd}$ stage) and the cooling capacities are 40 W at 82.9 K ($1^{st}$ stage) and 10 W at 20.5 K ($2^{nd}$ stage) with 6.0 kW of compressor input power. This pulse tube cryocooler is suited for commercial medium size cryopump. In performance test of cryopump with 2 stage pulse tube cryocooler, pumping speed for gaseous nitrogen is 4,300 L/s and the ultimate vacuum pressure is $7.5{\times}10^{-10}$ mbar.

• Nuclear Engineering and Technology
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• v.52 no.2
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• pp.360-365
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• 2020

A technique for the reduction of pulse pile-up effect in digital pulse-shape discrimination (PSD) of neutrons and gamma-rays with organic scintillation detectors is presented. The technique is based on an electronic reduction of the effective decay-time constant of scintillation pulses while retaining the PSD information of the pulses. The experimental results obtained with a NE213 liquid scintillation detector in a mixed radiation field of neutrons and gamma-rays are presented, demonstrating a figure of merit (FOM) of 1.20 ± 0.05 with an energy threshold of 350 keVee (electron equivalent energy) when the effective length of the pulses is reduced to 50 ns.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.912-921
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• 2009

Pulse-discharge technology (PDT) is an innovative technology which uses enormous energy developed by electric discharge for a very instant moment of time. Lately, it has been applied to make expanded sections at the ends of piles and anchors. The expanded section is formed by the deformation of bore-hole induced by shockwave energy developed in filling material by the pulse discharge. In this study, considering the phenomenon of pulse-discharge as an underwater explosion, finite element analyses were carried out to model the shockwave development by pulse discharge. The simulation technique was verified by comparing results with underwater discharge test results.

• Journal of the Optical Society of Korea
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• v.13 no.3
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• pp.335-340
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• 2009

Ultrashort pulse laser drilling of polycarbonate track-etched membrane (pTEM) material was used to fabricate a mouse embryo cell trapping device. Holes with a diameter of $2{\mu}m$ to $5{\mu}m$ were fabricated on a $10{\mu}m$ thick membrane using a femtosecond laser with a 150 fs pulse width and 775 nm wavelength and multiple-pulse irradiation. In cell trapping tests, the overall cell occupancy of the machined holes in the fabricated pTEM was found to be more than 80%. The results of a single pulse and multiple pulse irradiation were compared in terms of the surface quality. It was generally found that a single pulse with high energy was less desirable than irradiation with multiple pulses of lower energy.