• Title/Summary/Keyword: wave height energy

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A Study on the Waveform Analysis of Left KWAN Pulse Dignosis by the Pressure (단계별(段階別) 가압(加壓)에 따른 좌관부위(左關部位) 맥파(脈波) 변화(變化))

  • Kim, Gyeong-Cheol;Lee, Jeong-Won;Ryu, Kyeong-Ho;Kim, Jong-Hwan;Park, Ju-Yeon
    • The Journal of the Society of Korean Medicine Diagnostics
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    • v.13 no.1
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    • pp.19-35
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    • 2009
  • Objectives : In the study on the waveform analysis of radial artery pulse diagnosis, we need to establish fundamentals of contemporary pulse diagnosis research. To achieve certain experimental basis on traditional pulse diagnosis, we have to research the differences of pulse waveform according to pressure (in 5 level) and position (Chon, Gwan, Cheok in radial artery). As a first step, in present thesis, we tried to find the differences of pulse waveform according to pressure. Methods and Results : In this research, we analyzed seven parameters of the waveform at five levels of pressure. The parameters are E(so called 'energy', a representative of pulse strength), h1(height of percussion wave) and h2(height of subincisura). The results were as follows. 1. When we analyzed the change of the waveform according to pressure in the left Gwan, E, hl, h2 and A differed between 1st and 2nd grade, between 1st and 3rd grade, between 1st and 4th grade, between 1st and 5th grade, between 2nd and 3rd grade, between 2nd and 5th grade, between 3rd and 5th grade and between 4th and 5th grade in 95% confidence interval. 2. And t2, t4 differed between 1st and 2nd grade, between 1st and 5th grade, between 2nd and 4th grade, between 2nd and 4th grade, between 2nd and 5th grade, between 3rd and 4th grade, between 3rd and 5th grade and between 4th and 5th grade in 95% confidence interval. 3. W differed between 1st and 3rd grade, between 1st and 4th grade, between 2nd and 3rd grade, between 2nd and 4th grade, between 2nd and 5th grade, between 3rd and 4th grade, between 3rd and 5th grade, and between 4th and 5th grade in 95% confidence interval. 4. And h2/h1 differed between 1st and 4th grade, between 1st and 5th grade, between 2nd and 4th grade, between 2nd and 5th grade, between 3rd and 4th grade & between 3rd and 5th grade in 95% confidence interval. 5. There were differences between 1st and 2nd grade & between 2nd and 5th grade in the case of t4/t2 in 95% confidence interval. And there were differences 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% confidence interval. And were differences 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% confidence interval. Conclusions : As mentioned above, we conclude that the waveform analysis according to five grade pressure in the left Gwan shows the difference of waveform in each grade pressure.

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Behavior Analysis of Concrete Structure under Blast Loading : (II) Blast Loading Response of Ultra High Strength Concrete and Reactive Powder Concrete Slabs (폭발하중을 받는 콘크리트 구조물의 실험적 거동분석 : (II) 초고강도 콘크리트 및 RPC 슬래브의 실험결과)

  • Yi, Na Hyun;Kim, Sung Bae;Kim, Jang-Ho Jay;Cho, Yun Gu
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.5A
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    • pp.565-575
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    • 2009
  • In recent years, there have been numerous explosion-related accidents due to military and terrorist activities. Such incidents caused not only damages to structures but also human casualties, especially in urban areas. To protect structures and save human lives against explosion accidents, better understanding of the explosion effect on structures is needed. In an explosion, the blast load is applied to concrete structures as an impulsive load of extremely short duration with very high pressure and heat. Generally, concrete is known to have a relatively high blast resistance compared to other construction materials. However, normal strength concrete structures require higher strength to improve their resistance against impact and blast loads. Therefore, a new material with high-energy absorption capacity and high resistance to damage is needed for blast resistance design. Recently, Ultra High Strength Concrete(UHSC) and Reactive Powder Concrete(RPC) have been actively developed to significantly improve concrete strength. UHSC and RPC, can improve concrete strength, reduce member size and weight, and improve workability. High strength concrete are used to improve earthquake resistance and increase height and bridge span. Also, UHSC and RPC, can be implemented for blast resistance design of infrastructure susceptible to terror or impact such as 9.11 terror attack. Therefore, in this study, the blast tests are performed to investigate the behavior of UHSC and RPC slabs under blast loading. Blast wave characteristics including incident and reflected pressures as well as maximum and residual displacements and strains in steel and concrete surface are measured. Also, blast damages and failure modes were recorded for each specimen. From these tests, UHSC and RPC have shown to better blast explosions resistance compare to normal strength concrete.