• Title/Summary/Keyword: Yim pulse

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The measurements of thermophysical properties of ceramics by single rectangular pulse heating method in transient heat source (방형파펄즈가열법에 의한 세라믹스의 열물성 측정에 관한 연구)

  • Cha, K.O.;Lee, K.H.;Yim, Going
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.9 no.6
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    • pp.612-620
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    • 1999
  • Thermophysical properties of the high-dielectric ceramics were measured by a single rectangular pulse heating method. The values of thermal diffusivities, specific heats, and thermal conductivities were measured as a function of temperature ranging from room temperature to 1300 K.

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A NDT System using the Pulse-echo Method (펄스 반사법을 이용한 NDT 시스템)

  • Vhan, C.S.;Kim, K..;Cha, I.W.;Yim, K.H.
    • The Journal of the Acoustical Society of Korea
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    • v.5 no.1
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    • pp.35-40
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    • 1986
  • 본 연구는 펄스 반사법을 이용하여 금속 재료 단면의 영상을 얻는데 그 목적이 있다. 기존의 탐 상기는 대부분 A - 스캔 방식으로 결과를 전시하여 검사자가 직접 CRT 상에 나타난 결과를 판독해야 하므로 숙련자라 하더라도 어느정도 오차가 수반되며 판독에 시간이 요하는 등 불편이 따른다. 본 연구 에서는 판독 과정을 자동화함으로써 정확도와 검사 속도를 개선하였으며 탐촉 지점은 스텝핑모터를 이 용하여 일정 간격으로 제어하였다. 도 탐상 결과를 B-스캔 방식으로 영상 처리함으로써 재료 단면의 상 태 파악을 용이하게 하였다.

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The Effects of Electroplating Parameters on the Morphologies and Compositions of Nickel-Iron Alloy Electrodeposits (Ni-Fe의 도금 층의 조성과 표면 형상에 영향을 미치는 도금인자들에 관한 연구)

  • Ko, Yeong-Kwon;Yim, Tai-Hong;Lee, Jae-Ho
    • Journal of the Microelectronics and Packaging Society
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    • v.14 no.3
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    • pp.51-55
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    • 2007
  • Nickel iron (Ni-Fe) alloy coating was investigated. The effects of the current density, current type, pulse duration and bath compositions on the morphologies and surface hardness of nickeliron deposits as well as the chemical compositions were investigated. The morphologies, surface hardness and chemical compositions of nickel-iron deposits were varied with current density, current type and bath compositions. The surface hardness was increased up to $550{\sim}600Hv$ when PC plating was employed. Crackless coating was obtained when saccharin was added. The change of composition with thickness was analyzed with EDS and FESEM.

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Study on the Difference of Pulse Waveform Parameter with Applied Variations of Pressure (측정가압에 의한 좌관부위(左關部位) 맥파요인 변화에 대한 실험 연구)

  • Kim, Gyeong-Cheol;Lee, Jeong-Won;Ryu, Kyeong-Ho;Kang, Hee-Jung;Yim, Yun-Kyoung
    • Korean Journal of Acupuncture
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    • v.27 no.4
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    • pp.59-72
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    • 2010
  • Objectives : In the study on the waveform analysis of radial artery pulse diagnosis, we need to establish fundaments of contemporary pulse diagnosis research, and to find the change of pulse waveform parameter with applied variation pf pressure. Methods : As we will to do experimental research on the difference of pulse waveform on the radial artery with applied variations of pressure(5 stage-pressure) and measuring position(left KWAN). In this research, we analyzed the change of the waveform according to five stage pressure. Results : The results were as follows; When we analyzed the change of the waveform according to pressure in the left KWAN, E, hl, h2 and A were the difference between 8ths pressure grades in 95% trust section. And t2, t4 were the difference between 8ths pressure grades in 95% trust section. W was the difference between 8ths pressure grades in 95% trust section. And h2/h1 was the difference between 6ths pressure grades in 95% trust section. There is the difference between 1st and 2nd grade & between 2nd and 5th grade in the case of t4/t2 in 95% trust section. And there is the difference between 1st and 5th grade, between 3rd and 4th grade, between 3rd and 5th grade & between 4th and 5th grade in the case of W/A in 95% trust section. And there is the difference between 1st and 2nd grade, between 2nd and 3rd grade, between 2nd and 4th grade, between 3rd and 4th grade, between 3rd and 5th grade & between 4th and 5th grade in the case of A/E in 95% trust section. Conclusions : We found the statistically resonable differences between each pulse depending on the applied pressure. And Analysing the radial pulse(left KWAN) at 5 applied pressure levels may be useful to study on the pulse waveform diagnosis.

A study on the pulse symptoms of Shanghanlun (상한론(傷寒論)의 조문중(條文中) 맥증(脈證)에 관한 연구(硏究))

  • Kim, Jong-Soo;Park, Won-Hwan
    • The Journal of Dong Guk Oriental Medicine
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    • v.9
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    • pp.73-93
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    • 2000
  • Shanghanlun principally dealt with the differentiation of 'The six channels'(Taiyang, Yangming, Shaoyang, Tayin, Shaoyin, Jueyin), summing up such rich experiences as diagnoses and remedies about an acute fever before the Han dynasty, and establishing the basis of the differentiation of symptoms and signs based on prescriptions. And making it a principle to think of both pulse and symptoms important, it made a more organic method of diagnoses which compounded a reason, ncle, prescriptions and drugs, and considerably contributed to the development of Diagnostics. Therefore, as a result of classifying the contents concerned with the differentiation of Shanghanlun through the pulse symptoms, which is a way of research about the field of pulse feeling, it provided us with somewhat knowledge. 1. The pulse symptoms corresponds with the latter classification on the pulse symptoms. That is why, it seems, the traditional concept, which regarded the pulse and the symptoms as the basis of the differentiation and established the principle of the differentiation of symptoms and signs based on prescriptions, largely has an effect on the establishment of the latter pulse science. 2. The contents concerned with the pulse symptoms, including general principles and dicoction symptoms of each chapter, mounted up to 38%, and so the pulse symptoms informed that the pulse symptoms was the grounds of transformation and development, mechanism of differentiation of syndromes, advance or retreat of pathologic factors and application of drugs of each course of Shanghanlun. 3. Of pulse syndromes, there appeared Floating pulse most, and in addition there were also the high frequency of Yin pulse like Indistinctive pulse, Tense pulse, Deep pulse, and so on. 4. Any regularity between the pulse syndrome and the abdominal syndrome cannot be found.

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Development of 3 - Dimensional Ultrasonic Wind Direction Anemometer Measurement Technique Using Time Division Method (시분할 방식을 이용한 3차원 초음파 풍향풍속계 측정기술 개발)

  • Lee, Woo-Jin;Choi, Jae-Young;Kim, Kyung-Won;Yim, Jae-Hong
    • Journal of Sensor Science and Technology
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    • v.26 no.1
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    • pp.66-72
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    • 2017
  • The three dimensional ultrasonic anemometer was constructed to reduce the disadvantages of the two-dimensional anemometer and to be free from the use environment. Three pairs of transmitting and receiving ultrasonic sensors were designed to face each other at an angle of $45^{\circ}$ to the upper and lower surfaces at intervals of $120^{\circ}$. 200 kHz ultrasonic sensor Oscillation, transmission and reception, level detection, power supply circuit were designed and U, V, W wind speed vector components were obtained by measuring the time of first received ultrasonic pulse by transmitting pulse ultrasound. It is implemented as firmware in ARM Coretex-M3 processor so that horizontal and vertical wind direction and wind speed can be converted into digital signal by vector calculation. In this study, The three-dimensional ultrasonic anemometer can complement the disadvantages of the two-dimensional anemometer (mechanical and ultrasonic), and it is expected to gradually replace the two-dimensional anemometer due to its high utilization rate by collecting additional information such as vertical wind.

Investigation on the Effect of Organic Additives on the Electroformed Cu Deposits with Micro-patterns (유기물 첨가제가 마이크로 패턴 구리 전주 도금에 미치는 영향 연구)

  • Lee, Joo-Yul;Kim, Man;Lee, Kyu-Hwan;Yim, Seong-Bong;Lee, Jong-Il
    • Journal of the Korean institute of surface engineering
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    • v.43 no.1
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    • pp.1-6
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    • 2010
  • The effect of organic additives, 1-(3-sulfoproyl)-2-vinylpyridineium hydroxide (SVH) and thiourea (TU), on the precision copper electrodeposition was investigated with optical, electrochemical and x-ray diffraction techniques. It was found that SVH played a r ole as a n accelerator and TU as an i nhibitor during the electroreduction of cupric ions in acidic Cu electroplating solution. Through electrochemical measurements, TU showed more strong interaction with cupric ions than SVH and dominated overall Cu electroplating process when both additives were present in the solution. In the case of three dimensional Cu electrodeposition on the 20 ${\mu}m$-patterned Ni substrates, SVH controlled the upright growth of Cu electrodeposits and so determined its flatness, while TU prohibited the lateral spreading of Cu in the course of pulse-reverse pulse current adaptation. With microscopic observation, we obtained the optimum organic additives composition, that is, 100 ppm SVH and 200 ppm TU during the current pulsation.

Estimation of Setting Time and Early-age Strength of Concrete Using the Ultrasonic Pulse Velocity (초음파 속도를 이용한 콘크리트의 응결 및 초기 강도 추정)

  • Lee, Hoi-Keun;Lee, Kwang-Myong;Kim, Young-Hwan;Yim, Hyun-June
    • Journal of the Korean Society for Nondestructive Testing
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    • v.22 no.3
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    • pp.292-303
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    • 2002
  • This paper presents experimental results for early-age properties of concrete such as the setting time and strength, evaluated via the ultrasonic pulse velocity (UPV). Developing and using an automatically-recording monitoring system, the UPV's of mortar and concrete with various water to binder ratios (W/B) were measured during the first 24 hours. In addition, probe penetration and compression tests were conducted to measure the setting time and compressive strength, respectively. It was observed that the UPV's of mortar with high W/B remained constant during the first 6.5 hours and then abruptly began to increase at constant rates. On the other hand, the UPV of mortar with low W/B increased relatively slowly and gradually due to the setting retardation caused by the use of high range water reducing agent (HRWR). It was found that setting of concrete occurs when the UPV reaches a certain value. Moreover, it was concluded that the estimation formulas should incorporate the effects of W/B to more accurately estimate the early-age strength of concrete from the UPV.

Development of Control Method for Event Recorder in High Speed Train (고속전철용 Event Recorder를 위한 제어 방식 개발)

  • Song, Gyu-Youn;Yim, Hyun-Jae;Chang, Tae-Wook
    • Proceedings of the KSR Conference
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    • 2011.05a
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    • pp.1182-1188
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    • 2011
  • By storing various train information in running high speed train, we can analyze the cause of train accident efficiently. we have developed the smart and high available control method to control and manage the hardware modules. The hardware modules for event recorder consist CPU, Digital Input and Output, Pulse Input, Communication, Control Panel and Crash Protected Memory. The real time operation system is used to totally control and manage the various hardware modules. The main function of control method is collection of train information, calculation of train speed, interface with other on-board control system, storing and retrieving train information, and communication with Control Panel. In Control Panel, it displays the current train speed and the status of event recorder effectively. Also user interface is provided in Control Panel.

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Current Sampling Error in Digitally-Controlled AC Motor Drives (디지털 제어기로 인한 교류 전동기 제어 시스템의 전류 샘플링 오차 및 보상)

  • Yim, Jung-Sik;Sul, Seung-Ki
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.883-884
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    • 2008
  • 디지털 제어기는 벡터 제어(Vector Control) 구현에 적합하기 때문에, 현재 대다수의 고성능 교류 전동기 구동 시스템에 사용되고 있다. 디지털 제어기를 사용하는 교류 전동기 구동 시스템에 대한 기존의 연구는 주로 디지털 제어기의 시지연이 제어 성능에 미치는 효과에 주목하였다. 그리고 디지털 제어기의 전류 샘플링 오차에 주목한 연구들은 주로 전력 변환기기의 전압 변조(PWM, Pulse Width Modulation)와 디지털 제어기의 샘플링 순간과의 관계에 따른 전류 샘플링 오차에 대해 연구하였다. 본 논문에서는 기존의 연구에서는 다루어지지 않았던 디지털 제어기의 제로-오더-홀드(Zero-Order Hold) 특성에 의해 발생하는 전류 샘플링 오차를 다룬다. 이 오차는 전동기의 전기적 회전 주파수가 디지털 제어기의 샘플링 주파수에 비해 무시할 수 없을 정도로 커지는 경우 그 영향이 두드러지게 된다. 본 논문에서는 이러한 전류 샘플링 오차를 분석하고, 이것을 보상하는 방법에 대해 서술한다.

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