• 한국전자파학회논문지
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• 제15권1호
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• pp.29-35
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• 2004

광 펄스가 대기 공간을 통해 전파될 때, 광 펄스는 대기 교란으로 인해 감쇠되고 퍼지게 되며, 이러한 펄스 퍼짐은 광 수신단에서 도착되는 펄스의 요동으로 인해 발생한다. 디지털 광통신에서는 감쇠도 중요한 인자이지만 펄스 퍼짐이 더 중요한 인자로 작용한다. 이에, 본 논문에서는 교란 대기를 통해 전파되는 광 펄스의 퍼짐을 구하고, 이러한 펄스 퍼짐을 대기 교란 상수인 굴절률 구조함수로 나타내고 대기 교란 상태와 전송거리에 따른 펄스 퍼짐 정도를 시뮬레이션 하였다.

• 한국광학회지
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• 제5권1호
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• pp.37-44
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• 1994

유도 브릴루앙 반사광을 고출력 레이저에 응용할 때 요구되는 반사광 특성이 실험적으로 조사되었다. 집속 렌즈의 초점거리에 따른 유도 브릴루앙 반사광의 peak power 반사율과 위상공액도가 측정되었다. 또한 반사광 가운데 펄스압축된 부분만의 위상공액도가 측정되었다. 초점거리가 긴 경우(f=100cm) 반사광의 peak power가 입사광의 약 2배에 이르렀다. 이때 반사광 중에서 압축된 선두펄스만의 위상공액도는 약 90%로 다른 시간의 펄스보다 위상공액도가 우수했다. 공간적으로는 유도 브릴루앙 이득이 가장 큰 광축부분의 바사관이 최대의 펄스압축, peak power 반사율, 위상공액도를 보여서 유도 브릴루앙 산란을 응용할 때 가장 유용한 부분으로 확인되었다.

• 대한한의학원전학회지
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• 제27권1호
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• pp.111-122
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• 2014

Objective : The region, observation period, figuration of pulse, pulse frequency, process of diagnosis and related diagnostic methods in traditional pediatric pulse diagnosis were studied in this article. Method : The articles related to traditional pediatric pulse diagnosis in Traditional medical classics, and analysis to the characteristics of it was done, then lastly, the principle of pulse manifestation and the meaning of application to modern times were considered. Result & Conclusion : It is difficult to catch the figuration of pediatric pulse because of dynamic change of body conditions, fast heartbeat and narrow region of pulse. Therefore, the pulse diagnosis appropriated for children have been developed and combined with the special diagnosis methods, for example, palpation of forehead and observation of index finger. The traditional pediatric pulse diagnosis is done with just one finger palpation in the period of 3 to 5 years old to identify the speed, length, size and height of pulse. The standard average of pulse frequency is 7~8 par breath in the period of 3 to 5 years old according to traditional medical classic.

• 동의생리병리학회지
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• 제21권6호
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• pp.1381-1387
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• 2007

Pulse diagnosis that is one of important examination methods in traditional oriental medicine has been investigated for the standardization in many ways. Pulse analyzer device and clinical studies have been tried for this purpose. Additionally, literature study has significance for this standardization. In this study, we analyzed pulse types in literatures from the viewpoint of physics. We refered to Maijing, Maijue, siyanjuyao, Binhumaixue, Yixuerumen, zhenjiazhengyan. We established some physical factors for analysis. This factors that can be detected through pulse analyzer are depth, speed, power, width, and length. In this study, we defined 18 kinds of pulse types among 28 total types by physical factors. Furthermore, 6 kinds of pulse types were classified as basic pulse from these. The results of this study will improve the pulse analyzer to detect these pulse types.

• 전자공학회논문지B
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• 제31B권7호
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• pp.211-218
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• 1994

Stochastic computation employs random pulse streams to represent numbers. In this paper, we study a new method to implement the number system which uses the ratio of the numbers of ones and zeros in the pulse streams. In this number system. if P is the probability that a pulse is one in a pulse stream then the number X represented by the pulse stream is defined as P/(1-P). We propose circuits to implement the basic operations such as addition multiplication and sigmoid function with this number system and examine the error characteristics of such operations in stochastic computation. We also propose a neuron model and derive a learning algorithm based on backpropagation for the 3-layered feedforward neural networks. We apply this learning algorithm to a digit recognition problem. To analyze the results, we discuss the errors due to the variance of the random pulse streams and the quantization noise of finite length register.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.1329-1334
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• 2004

The most compact and convenient pulse tube cryocooler for practical applications is the coaxial type. It can replace Stirling cryocooler without any change to the Dewar or the connection to the cooled devices. The experimental results of the coaxial inertance tube pulse tube cryocooler for cooling superconductor RF filter are presented in this paper. To find optimal conditions of inertance tube pulse tube cryocooler, no load temperature according to the variations of inertance tube volume, reservoir volume are measured, and the cool down characteristics at the particular conditions are presented. In case of the coaxial type inertance tube pulse tube refrigerator, cool down time is the lowest in the inertance tube diameter of 1.3 mm and inertance tube length of 1900 mm and lowest temperature is 112K. This results are not satisfactory for practical applications. So, We propose vacuum insulation between regenerator and pulse tube in the Stirling type coaxial pulse tube cryocooler. Stirling type coaxial pulse tube cryocooler with the vacuum insulation between regenerator and pulse tube was designed and manufactured by KIMM(Korea Institute of Machinery and Materials). The optimal conditions will be tested for Stirling type coaxial pulse tube cryocooler with the vacuum insulation between regenerator and pulse tube.

• Journal of Advanced Marine Engineering and Technology
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• 제23권5호
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• pp.671-677
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• 1999

This study has been performed to investigate REW(relative electrode wear) in condition of vari-ous pulse-on duration using the copper and graphite electrode with change of the electrode size on the heat treated STD11 which is extensively used for metallic molding steel with the EDM. The results obtained are as follows; a) Graphite has much benefits than copper electrode when rapid machining is done without electrode wear, b) Neative REW result from the electrode that is very liable attach to decomposition carbide c)Increasing of machining time cause to increase wear length of the copper electrode and decrease wear length of the graphite electorde d)The more pulse-on duration copper electrode has the less REW. e) The edge portion of the electorde wears remarkably at the beginning of machining,.

• 한국초전도ㆍ저온공학회논문지
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• 제9권3호
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• pp.26-31
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• 2007

In recent years. YBCO coated conductor (CC) called as second generation HTS (high temperature superconducting) wire has been developed as a suitable material for resistive superconducting fault current limiter (SFCL). For designing the SFCL. the required length of superconducting wire is inverse proportional to the maximum temperature reached when a fault occurs. Since the required length strongly affects a manufacturing cost, it is the most important parameter to determine the maximum temperature reached. It is necessary to observe the repetitive over-current characteristics of HTS wire. This paper attempts to measure the variation of critical current of YBCO CC after repetitive over-current pulse. No degradation of the critical current of CC sample was observed by applying 100 times over-current pulse which makes temperature above 400 K after 100ms. This study can be useful in designing optimally resistive SFCL employing YBCO CC. The maximum permissible temperature can be set to 400K. so wire length could be reduced by 30% compared in case of 300K-criterion.

• 대한한의진단학회지
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• 제19권1호
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• pp.47-54
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• 2015

Objective Wave reflection is an important factor that determines the shape of the pulse wave. The purpose of this study is to compare the conventional method used for estimating the reflection site of pulse with a cardiovascular simulator. Methods: In this study, cardiovascular simulator with one elastic tube was used. The pressure and flow was measured simultaneously at three different points. The measured data were used to the conventional methods to estimate the pulse wave reflection site. The results were compared with the known length which were the distances from the measured points to the end of tube. Results & Conclusions: There is a significant error with the time domain method. While, the reflection site with the frequency domain method was similar to the actual reflection site.

• Nuclear Engineering and Technology
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• 제52권2호
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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.