• Title/Summary/Keyword: Pulse reaction

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Studies on the Mathematical Modelling of the Pulse-CVI for the Infiltration of Siliconcarbide from Methyltrichlorosilane (메틸삼염화규소로부터 탄화규소 침착의 Pulse-CVI에 대한 수치모사 연구)

  • Kim, In-Goo;Kim, Min-Ki;Chung, Gui-Yung
    • Composites Research
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    • v.18 no.5
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    • pp.27-33
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    • 2005
  • In this research, the mathematical modelling of the pulse-CVI (Chemical Vapor Infiltration) for the preparation of siliconcarbide/carbon composite. Each pulse consists with the gas injection time, the reaction time and the evacuation time. Effects of the reaction time and the evacuation time were studied. Additionally, the effects of the reactant concentration and the pressure were observed. The benefits of the pulse-CVI such as the uniform infiltration of siliconcarbide into the carbon preform and the short reaction time were certified.

Tacho Pulse Non-uniformity Effects on Pulse Count Method (타코펄스 불균일성으로 인한 펄스개수측정방법 영향성)

  • Son, Jun-Won
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.49 no.4
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    • pp.301-309
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    • 2021
  • Pulse count method is the classical reaction wheel speed detection method. In this study, we represent the pulse count method as mathematical equations. Instead of rotation speed, we model the reaction wheel rotation through rotation angle during sampling periods. We verified the effectiveness of the proposed model by comparing the pulse counts variation and averaging method effects from the model and previous research results. Then, we add tacho pulse non-uniformity to this verified model, and examine the errors of pulse count method. We express the measurement error increasement due to non-uniformity as mathematical equations, and also shows the requirement of moving average numbers to offset the measurement errors.

Error Analysis of Reaction Wheel Speed Detection Methods Due to Non-uniformity of Tacho Pulse Duration (타코 펄스 불균일성이 존재하는 반작용휠의 속도측정 방법 오차 분석)

  • Oh, Shi-Hwan;Yong, Ki-Lyuk
    • Aerospace Engineering and Technology
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    • v.8 no.2
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    • pp.92-97
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    • 2009
  • Two conventional speed detection methods (Elapsed-time method and Pulse-count method) are analyzed and compared for a high speed motor with digital tacho pulse with non-uniformity. In general, the elapsed-time method usually has better performance than a pulse-count method in case sufficiently high speed clock is used to measure the time difference. But if a tacho pulse non-uniformity exists in the reaction wheel - most of reaction wheel has a certain amount of non-uniformity - the accuracy of the elapsed-time method is degraded significantly. Thus the performance degradation is analyzed with respect to the level of non-uniformity of tacho pulse distribution and an allowable bound is suggested.

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A Feasibility Study of Pulse Rate Per Respiration as an Indicator for the Reaction to Cold Stress (냉자극에 대한 맥율 변화 예비 연구)

  • Bae, Jang Han;Jeon, Young Ju;Kim, Hyunho;Kim, Jaeuk U.
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.28 no.6
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    • pp.668-673
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    • 2014
  • Cold and Heat pattern identification(CHPI) in traditional East Asian medicine(TEAM) is one of the major indicator to distinguish characteristics of disease and to determine treatment method. Basic parameters to determine CHPI include the pulse rate, respiration rate, and pulse power. Studies to associate physiological responses of human body by cold stress(CS) with CHPI in TEAM were rarely done so far. This study aims to explore the effects of cold stress on pulse signal via a feasibility study for three subjects and investigate some indices which can reflect autonomic nerve reaction(ANR). We measured radial pulse signals and respiration signal of the investigated subjects before the CS, during the CS which continues for 5 minutes, and immediately after the CS, respectively. Finally, we analyzed the pulse rate (P), respiration rate (R), pulse power, pulse depth, and pulse rate per respiration (P/R ratio). As a result, the P/R ratio showed a consistently decreasing tendency through the CS stimulation process, while other parameters behaved more complex and in subject-specific ways. It implies that, among candidate parameters, the P/R ratio is a simple but the most probable parameter that can be used as the ANR indicator. This result is also consistent with the theory in TEAM scripts, in which the P/R ratio is predicted to be a direct indicator for the CHPI. This pilot study shows that P/R ratio can be more appropriately associated with the ANR than heart rate or respiration rate alone. Extensive studies will be necessary to verify or confirm the P/R ratio as an appropriate and well defined parameter for ANR.

Error Analysis of Reaction Wheel Speed Detection Methods (반작용휠 속도측정방법의 오차 분석)

  • Oh, Shi-Hwan;Lee, Hye-Jin;Lee, Seon-Ho;Yong, Ki-Lyuk
    • Journal of Astronomy and Space Sciences
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    • v.25 no.4
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    • pp.481-490
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    • 2008
  • Reaction wheel is one of the actuators for spacecraft attitude control, which generates torque by changing an inertial rotor speed inside of the wheel. In order to generate required torque accurately and estimate an accurate angular momentum, wheel speed should be measured as close to the actual speed as possible. In this study, two conventional speed detection methods for high speed motor with digital tacho pulse (Elapsed-time method and Pulse-count method) and their resolutions are analyzed. For satellite attitude maneuvering and control, reaction wheel shall be operated in bi directional and low speed operation is sometimes needed for emergency case. Thus the bias error at low speed with constant acceleration (or deceleration) is also analysed. As a result, the speed detection error of elapsed-time method is largely influenced upon the high-speed clock frequency at high speed and largely effected on the number of tacho pulses used in elapsed time calculation at low speed, respectively.

Sweating Reaction of Men Adults - Centered on Athletes and Non-Athletes - (성인(成人) 남자(男子)의 발한(發汗) 반응(反應)에 관한 연구 - 운동선수(運動選手)와 비운동선수(非運動選手)를 중심(中心)으로 -)

  • Shim, Boo-Ja
    • Journal of Fashion Business
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    • v.3 no.1
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    • pp.125-137
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    • 1999
  • The present study aims to reveal the sweating reaction of male adults, focused on athletes. With six subjects (3 athletes and 3 non-athletes) in two different conditions of ambient temperature (I : $25\pm1.0^{\circ}C$, II : $29.5\pm1.0^{\circ}C$), their total sweat rate, local sweat rate, skin temperature, physiological reaction (rectal temperature, blood pressure, and pulse rate), and psychological reaction (thermal, moisture, comfort, and perceptive sweat sensations) were measured. The comparison gave the following results: Total sweating rate was greater in non-athletes, while the two groups had more perspiration in ambience II. Local sweating rate in both ambiences was the greatest in the central breast area (athletes) and the infrascapular area (non-athletes). The mean skin temperature had more changes of increase and decrease in athletes. As to physiological reaction, non-athletes had lower rectal temperature and blood pressure as well as higher pulse rate. As for psychological reaction in Ambience II, the 4 sensations were mostly 'hot', 'humid', 'uncomfortable', and 'sweaty'.

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Study on Electrochemical Properties of TBT(Tributyltin)

  • Park, Chil-Nam;Yang, Hyo-Kyung
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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    • v.10 no.S_4
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    • pp.173-179
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    • 2001
  • The chemical behavior and properties of the redox state of environmental pollutants was investigated using electrochemical methods. The purpose was to measure the variations in the redox reaction of differential pulse polarograms and cyclic voltammograms. The results observed the influences on redox potential and current of various factors including concentration, temperature, salt, and pH. These were established factors as the effect of the redox reaction. It can be clearly recognized that the electrode reaction are from reversible to irreversible processes. Also, it was mixing with reaction current controlled.

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Chemical Properties of Co(II) Compound Containing Endocrine Disrupter, Bis-Phenol A

  • Park, Chil-Nam
    • Journal of Environmental Science International
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    • v.11 no.2
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    • pp.131-137
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    • 2002
  • The chemical behavior and properties on the redox state of environmental pollutant has been investigated by electrochemical methods. We carried out to measure the variations in the redox reaction of differential pulse polarogram and cyclic voltammogram. The results observed the influences on redox potential and current of various factors with temperature and pH. These were established factors as the effect of the redox reaction. It can be clearly recognized that the electrode reaction are from qusi-reversible to irreversible processes. Also, it was mixing with reaction current controlled. The bits-phenol A in the waste water was made to compound with cobalt ion and it take away from the separation into compound. The $Co(BPA)_2$ compound was not found to be dissociation in waste water. However, this compound is avery unstable(K=1.02) and for a while, it was to be a dissociation. Therefore, we believed that it was likely to a toxic substance.

A Study on the Deficiency-excess Pattern of the Rapid Pulse (삭맥(數脈)의 허실(虛實)과 미발현(未發現))

  • Hong, Seung-Min;Park, Hwi-Eun
    • Korean Journal of Oriental Medicine
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    • v.16 no.3
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    • pp.33-44
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    • 2010
  • Pulse diagnosis is considered one of the most important diagnostic methods in traditional Korean medicine. Nonetheless, there have been troubles of using pulse diagnosis practically, for the lack of its differential standards and standardized terminology. Rapid pulse belongs to the several traditional pulse types. Rapid pulse was first mentioned in the chinese medical book Haungdineijin that matched it to the fever as well as yang in the human body. Meanwhile, chinese doctors in Ming Ching dynasty of China suggested that rapid pulse meant more of the yin, cold-related reaction than yang and fever. In this study, we organized the past arguments of the rapid pulse and went back tracking what biological activities could be possibly linked to the rapid pulse. Thus, we figured out that the inflammatory mechanism has a close connection with the rapid pulse. The definition of the rapid pulse in Haungdineijin was indicating the acute inflammatory response, while in Ming Ching dynasty, it indicated the chronic inflammation. This is the deficiency-excess pattern of the rapid pulse. Furthermore, we discussed the nonexpression pattern of the rapid pulse which could be happened in case of the heat stroke, etc.