• Progress in Superconductivity and Cryogenics
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• v.8 no.3
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• pp.63-69
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• 2006

This paper describes the effect of rotating frequency on the pulse tube of Stirling type pulse tube refrigerator. Various conditions were analyzed by two-dimensional analysis with several dominant non-dimensional parameters. With the additional pressure term influenced by centrifugal force in rotating condition, the linearized conservation equations of mass, momentum, energy of the gas were solved to obtain the first order variables and calculate the enthalpy flow in rectangular coordinates. The rotational effect in pulse tube for the refrigerator's performance were quantitatively evaluated. According to the first order analysis, the enthalpy flow decreases with the rotating speed.

• Transactions of Materials Processing
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• v.26 no.5
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• pp.314-322
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• 2017

In the high-speed forming analysis, dynamic material properties considering a high strain rate are required. The split Hopkinson pressure bar (SHPB) experiment was performed for measuring dynamic material properties under high strain rate. The pulse shaping method was used to improve the accuracy of the SHPB experiment. A pulse shaper attached to the front of the incident bar was used for specimen dynamic stress equilibrium through stress wave control. Numerical analysis and SHPB test were performed to verify whether the pulse shaper affects the dynamic stress equilibrium in copper and Al6061 specimens. The results of SHPB test and numerical analysis show that the pulse shaper contributes to the dynamic stress equilibrium. Based on the improved stress equilibrium using a pulse shaper, the flow stress curves for copper and Al6061 materials were obtained at strain rates of 1344.4/sec and 1291.6/sec, respectively.

• The Journal of the Society of Korean Medicine Diagnostics
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• v.13 no.2
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• pp.88-116
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• 2009

Background : EBM (the evidence based medicine) is the direction of the development for oriental medicine. The pulse meter-analyzer is the important part to standardize the pulse diagnosis. When we set up the direction of the study on the pulse meter-analyzer, the awereness about the pulse meter and analyzer of the clinical oriental medical doctors as consumers is very important. Objectives : In order to prepare for the mutual study and the export strategy on the pulse meter-analyzer of Korea and China, the attitude of the study and the grasp of the awereness about the pulse meter-analyzer of the Chinese medical doctors are very important. Methods : We developed the several items as the important factor of the development of the pulse meter and analyzer. They were translated by chinese medical doctor. The investigation for demend was conducted during 3 months in Guangzhou City, Guangdong Province, China. The results of the investigation was done the statistical method of frequency analysis, Chi-squared test, correspondence analysis. Results : The most important differentiation of symptom is the symptom of JANG-BU(臟腑). The method of the utility in the pulse diagnosis is Chon-Gu (寸口) pulse diagnosis and the research on Chon-Kwan-Cheok(寸關尺) is the most important measurement factor. And the typical the old pulse is the little-fine weak pulse. The pulse meter-analyzer is most suitable to the diagnosis of the hypertension and the arteriosclerosis. Conclusion : The development of the pulse analyzer including the requests of Korean and Chinese medical doctors is very important. Specially the researches on the influence factors of the traditional diagnosis and the environment of the measurement are important for developing the pulse analyze.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.11
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• pp.508-514
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• 2005

In this paper, it was investigated the characteristics of PD(partial discharge) pulse shapes in oil and the possibility of TF(Time-Frequency) analysis for the discrimination of air corona in on-site PD measurement of oil transformers. For the purpose, single and multiple discharges combined with oil discharges and air corona were generated and measured by use of artificial models through the HFPD pulse detector and the oscilloscope. PD pulse shapes were different according to the type of defects, especially including air corona- pulses. Also, through the TF analysis, data clusters could be classified each other in the TF Map, even in the case of multiple discharges. Therefore, it is known that TF analysis could be aprlied for the improvement of on-site PD measurement in oil transformers.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.1433-1437
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• 2005

Until now, strain gage technique and accelerometer for the diagnosis safety of constructions are used widely. However, the limits of these methods are revealed. But Electronic Speckle Pattern Interferometry(ESPI) that uses Pulse Laser is noncontact, whole-field, real-time measuring method also dull to disturbance and can achieve test result in a very short time. It has various strong point in spot application, swift establishment, and dynamic conduct analysis for the entire field of Laser illuminate. This author analyzed vibration characteristic of using the Pulse ESPI System, the diagnosis safety of bridges, to simplify the analysis of the dynamic conduct of a large construction.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.4
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• pp.183-188
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• 2006

Abstract - In order to investigate the possibility of separating PD(partial discharge) and noises through the pulse analysis by use of a HFCT, pulse shapes measured by a resistive sensor and a HFCT were analyzed and adequate PA(pulse analysis) algorithms were studied. For the purpose, the HFPD detection and PA system has been developed. Also void discharges and air corona were adopted as the artificial defect and noises, respectively. As a result, it is possible to separate partial discharges and noises through the PA method using the $100kHz{\sim}20MHz$ frequency range HFCT. It is expected to apply the developed system to on-site PD measurements for the electric equipments.

• The Journal of Korean Medicine
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• v.32 no.4
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• pp.139-148
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• 2011

Objective: The purpose of this study was to investigate the effect of food intake on the Fourier components of radial pulse wave. Methods: Thirty-one healthy male subjects participated in this study. Radial pulse was measured using 3 dimensional pulse imaging system (DMP-3000) before, right after, 40 minutes after, 80 minutes after and 120 minutes after food intake. Fourier transform was performed and the frequency and amplitude of Fourier components were analyzed. Results: 1. The frequency and the amplitude of Fourier components of radial pulse wave increased significantly after food intake. 2. The frequency of Fourier components increased right after food intake and then gradually decreased as time passed, however the amplitude of Fourier components increased and maintained certain levels and patterns throughout the experimental period of 120 minutes. 3. The change ratios of the frequency and the amplitude of Fourier components after food intake varied with the pulse measuring locations. Conclusions: Food intake exerts an influence on radial pulse wave, resulting in increase of frequency and amplitude of Fourier components. The change ratios of the frequency and the amplitude of Fourier components after food intake varied with the pulse measuring locations.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.7A
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• pp.986-993
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• 2000

In this paper, we analyze transmission characteristics of ultrashort laser pulses using the properties of high-order pulses which are systematically obtained following their orders. The high-order pulses are easily derived from a modified PRS system model. But we make clear they are very useful to cover wider area and to show more accurate transmission characteristics of ultrashort pulses than Gaussian or Sech pulse approximations used conventionally. These are based on the fact that the spectra and bandwidths of the high-order pulses are geautifully related to their orders. First modifying the generalized PRS system model, we propose a new model for deriving any type of high-order pulse. And we offer a novel analysis method of ultrashort pulse transmission varying the order of the pulse from n=1 to n=100, we obtain spectra of ultrashort pulses with 1(ps)∼150(fs) FWHM's, which are widely used in optical pulse communications. One-step further, we derive PSD's of their pulse-tr ins when they are applied to Unipolar signaling scheme. These PSD's are decided in the range of possible pulse intervals. All of these results are not only coincided with some conventional experimental works but will be applied to any pioneering ultrashort pulse in the future.

• Nuclear Engineering and Technology
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• v.51 no.4
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• pp.1081-1090
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• 2019

Detailed pulse shape analysis of a Geiger-$M{\ddot{u}}ller$ counter is performed to understand the pulse shape dependence on operating voltage. New data is presented to demonstrate that not all pulses generated in a GM counter are identical. In fact, there is a strong correlation between the operating voltage and the pulse shape. Similar to detector deadtime, pulse shapes fall in three distinct regions. For low voltage region, where deadtime was reported to reduce with increasing voltage, pulse generated in this region was observed to have a fixed pulse width with a variable tail. The pulse width and fall time of the tail was observed to be a function of applied voltage; exponentially reducing with increasing voltage with an exponent of negative 6E-04 and 2E-03 respectively. The second region showed a pulse without any significant tail. During this time the detector deadtime was earlier reported to be at its minimum. The highest voltage region demonstrated a different deadtime mechanism where the second pulse was reduced in width. During this time the deadtime seemed to be increasing with increasing voltage. This data allows us to gain some unique insight into the phenomenon of GM detector deadtime not reported thus far.

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.294-298
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• 2000

A new pulse multiplication technique based on 6-pulse thyristor converters is proposed in this paper. With the proposed technique 12-pulse 18-pulse and 24-pulse operations have been obtained both on the input current and on the output voltage. A control strategy over the whole range of phase angle is provided along with sophisticated input current and output voltage analysis. Experimental results from a laboratory prototype verify the proposed theory.