• Title/Summary/Keyword: wave-energy

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Comparative Study on the Pulse Wave Variables and Sasang Constitution in Cerebral Infarction Patients and Healthy Subjects (뇌경새(腦梗塞) 환자(患者)와 건강인(健康人)의 맥상(脈象)과 사상체질(四象體質)에 관(關)한 연구(硏究))

  • Ko, Ki-Duk;Kim, Kyung-Yo;Kim, Jong-Yeol;Lee, Si-Woo;Joo, Jong-Cheon
    • Journal of Pharmacopuncture
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    • v.10 no.2 s.23
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    • pp.119-132
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    • 2007
  • This study was performed to determine whether a pulse analyzer was useful 1) to characterize the variables of pulse wave of cerebral infarction patieno (CI), compared with those of healthy subjects, as well as 2) to determine Sasang Constitution in CI and healthy subjects. 1. Calibrated in Gwan, the amount of energy(Energy), height of main peak(H1), height of aorticvalley(H2), height of aortic peak(H3), total area of pulse wave(At), and area of main peak width(Aw) of the CI group were higher than those of the healthy group. 2. Calibrated in Cheek, Energy, H1, H2, H3, height of valve valley(H4), At, Aw, and main peak angle(MPA) of the CI group were higher than those of the healthy group. 3. Among the healthy (subjects) group, Taeumin showed the highest contact pressure(CP) and height of valve peak(H5) calibrated in Chon. The main peak width divided by whole time of pulse wave(MPW/T) calibrated in Gwan and Cheok, was highest in Soyangin and was lowest in Taeumin. The H3 divided by H1(H3/H1) and the time to valve valley minus the time to main peak and divided by T[(T4-T1)/T] calibrated in Cheek were highest in Soyangin. The time to main peak(T1) was longest in Soumin. 4. Among the CI group, At calibrated in Chon was widest in Taeumin and was narrowest in Soumin The time to aortic peak(T3) calibrated in Cheek was longest in Soumin and was shortest in Soyangin. The time to valve peak(T5) was shortest in Soyangin. 5. There were main effects of cerebral infarction in the area of systolic period(As) and area of diastolic period(Ad) calibrated in Chon, Energy calibrated in Cwan, and Energy, H1, H2, H3, (H4+H5)/Hl, and MPA calibrated in Cheek. 6. There were main effects of Sasang Constitution in (T4-T1)/T, area of systolic period(As), and Ad calibrated in Chon. 7. The interactions between the cerebral infarction and Sasang Constitution were observed in H5/H1 , T, At, As, Ad, and MPA calibrated in Chon, H4, T4, (T4-T1)/T, As, and Ad calibrated in Cwan, and 74,75, and MPW calibrated in Cheok. Therefore, we concluded that pulse analyzer was useful to determine the risk degree of cerebral infarction and Sasang Constitution.

A study on the effect of discharge in a multiple spark ignition engine (다회수 스파크 점화기관의 방전효과에 관한 연구)

  • 이성열;한병호
    • Journal of the korean Society of Automotive Engineers
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    • v.11 no.5
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    • pp.55-64
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    • 1989
  • The effect of discharge have been investigated for condition of spark in a multiple spark ignition engine, as the spark duration, capacitive and inductive discharge energy were calculated for condition of spark by ignition wave and energy formula. The useful portion of spark discharge is divided into capacitance portion and inductance portion. It was found that capacitive discharge energy and spark duration were increased according to increasing number of spark, and inductive discharge energy was increased according to increasing spark interval. Therefore engine torque was increase and lean misfire limit was extended comparing with the standard ignition system. It found that spark energy was discharged within ignition delay period availability acted on the formation and growth of flame kernel, and total spark energy was increased according to increasing number of spark times, but discharged spark energy after ignition delay became unavailable energy. And the capacitive discharge energy has the dominant effect for stoichiomeric or not very rich air-fuel mixture but inductive discharge energy has the dominant effect for lean air-fuel mixture.

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The Hammer Energy Delivered to the Drilling Rod in the SPT 1 (표준관입시험시 롯드에 전달되는 해머의 낙하에너지 평가 1)

  • 조성민;정종홍;김동수;이우진
    • Proceedings of the Korean Geotechical Society Conference
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    • 2001.03a
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    • pp.469-476
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    • 2001
  • The Ν-value in the standard penetration test(SPT) is affected by the magnitude of the rod penetration energy transmitted from the falling hammer as well as the geotechnical characteristics of the ground. Understanding of the striking energy efficiency in the SPT equipment is getting important for that reason. The energy efficiencies of the doughnut hammer with the hydraulic lift system and the automatic trip hammer system were investigated through field tests using the instrumented rod and wave-signal acquisition systems including the pile driving analyzer(PDA) . The rod energy ratio, ΕR$\_$r/ was defined as the ratio of the energy delivered to the drilling rod to the potential free-fall energy of the hammer. It appears that the type of the hammer and lift/drop system had a strong influence on the energy transfer mechanism and ΕR$\_$r/ also varies according to the energy instrumentation system and the analysis methods.

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The Hammer Energy Delivered to the Drilling Rod in the SPT 2 (표준관입시험시 롯드에 전달되는 해머의 낙하에너지 평가 2)

  • 조성민;정종흥;이우진;김동수
    • Proceedings of the Korean Geotechical Society Conference
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    • 2002.03a
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    • pp.71-78
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    • 2002
  • The N-value from the standard penetration test(SPT) is affected by the magnitude of the rod penetration energy transmitted from the falling hammer as well as the geotechnical characteristics of the ground. Understanding of the striking energy efficiency in the SPT equipment is getting important for that reason. The energy efficiencies of the various type of equipment were investigated through field tests using the instrumented rod and wave-signal acquisition systems including the pile driving analyzer(PDA). The rod energy ratio, ERr was defined as the ratio of the energy delivered to the drilling rod to the potential free-fall energy of the hammer. It appears that the type of the hammer and lift/drop system had a strong influence on the energy transfer mechanism and ERr also varies according to the energy instrumentation system and the analysis methods.

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Effect Relationship among Korean Wave Involvement, National and Tourist Destination Image and Visit Intention (한류관여도와 국가 및 관광지 이미지 그리고 방문의도와의 영향관계)

  • Lee, Jong-Joo
    • The Journal of the Korea Contents Association
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    • v.16 no.10
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    • pp.454-466
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    • 2016
  • The Korean wave refers to the spread of Korean popular culture from China to all over the world. The Korean wave has been improving the national image and creating a new brand value for Korea as a symbolic soft power. Its spread has been operating as a kind of energy that is fueling national competition. The Korean wave creates a new type of tour and increases tourists' intention to visit special places revealed indirectly through mass media. People can vary highly in terms of awareness, attitude and behavioral pattern according to the degree of care for and interest in something. This is called involvement. Three hypotheses were established to study the effect of the Korean wave in terms of involvement. First of all, it confirms whether the Korean wave involvement affects national image and image as a tourist destination. Second, it confirms whether national image affects Korea's image as a tourist destination. Third, it confirms whether the Korean wave involvement affects intention to visit Korea. The certification results of these hypotheses confirm that the Korean wave affects national image, Korea's image as a tourist destination, and intention to visit Korea. The national image also partly affects its image as a tourist destination.

A study on evaluation of ship motion in irregular waves (불규칙 파랑 중 선체 동요 평가에 관한 연구)

  • LEE, Chang-Heon;CHOI, Chan-Moon;AHN, Jang-Young;KIM, Seok-Jong;KIM, Byung-Yeob;SHIGEHIRO, Ritsuo
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.51 no.4
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    • pp.504-511
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    • 2015
  • In this paper, the results of evaluating the passenger comfort due to the standard deviation of acceleration in vertical and lateral direction regarding the ship response in irregular wave by ordinary strip method in regular wave and energy spectrum using linear superposition theory in order to evaluate the motion of experimental ship are as follows. According to the results of ship response, it was possible to find that, in order to reduce the motion of ship, a ship operating in bow sea was more stable than in quartering sea. In the results of analyzing the standard deviation of acceleration in vertical direction according to each component wave pattern, when there was a wave length of 56m and an average wave period of 6 sec, most of cases showed the peak value. And among them, the standard deviation was 0.35 which was the highest in head sea. And in case of lateral direction, the maximum value was shown in a wave length of 100m and an average wave period of 8 sec. And it was 0.16 in beam sea and ${\chi}=150^{\circ}$. In the evaluation of passenger comfort due to standard acceleration in vertical and lateral direction, it was 80% in head and bow sea. On the other hand, it was shown to be 15% in follow sea. Accordingly, when the expected wave height in a sea area where a training ship was intended to operate was known, it was possible to predict the routing of ship. And altering her course could reduce the passenger comfort by approximately 50%.

Global performances of a semi-submersible 5MW wind-turbine including second-order wave-diffraction effects

  • Kim, H.C.;Kim, M.H.
    • Ocean Systems Engineering
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    • v.5 no.3
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    • pp.139-160
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    • 2015
  • The global performance of the 5MW OC4 semisubmersible floating wind turbine in random waves was numerically simulated by using the turbine-floater-mooring fully coupled and time-domain dynamic analysis program FAST-CHARM3D. There have been many papers regarding floating offshore wind turbines but the effects of second-order wave-body interactions on their global performance have rarely been studied. The second-order wave forces are actually small compared to the first-order wave forces, but its effect cannot be ignored when the natural frequencies of a floating system are outside the wave-frequency range. In the case of semi-submersible platform, second-order difference-frequency wave-diffraction forces and moments become important since surge/sway and pitch/roll natural frequencies are lower than those of typical incident waves. The computational effort related to the full second-order diffraction calculation is typically very heavy, so in many cases, the simplified approach called Newman's approximation or first-order-wave-force-only are used. However, it needs to be justified against more complete solutions with full QTF (quadratic transfer function), which is a main subject of the present study. The numerically simulated results for the 5MW OC4 semisubmersible floating wind turbine by FAST-CHARM3D are also extensively compared with the DeepCWind model test results by Technip/NREL/UMaine. The predicted motions and mooring tensions for two white-noise input-wave spectra agree well against the measure values. In this paper, the numerical static-offset and free-decay tests are also conducted to verify the system stiffness, damping, and natural frequencies against the experimental results. They also agree well to verify that the dynamic system modeling is correct to the details. The performance of the simplified approaches instead of using the full QTF are also tested.

Explosion Phenomena and Energy Transformation (폭발현상과 에너지변환)

  • 윤재건
    • Proceedings of the Korea Society for Energy Engineering kosee Conference
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    • 1998.05a
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    • pp.87-94
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    • 1998
  • 폭발현상(explosion phenomena)이 항상 연소(combustion)를 수반하는 것도 아니고, 연소현상이 항상 폭발적으로 일어나는 것이 아님에도 불구하고 많은 사람들은 폭발과 연소 사이에 밀접한 관계가 있는 것으로 생각하고 있다. 일반적으로 폭발이라고 하면 우선 큰 소리와 건물이나 실내의 파괴를 연상한다. 폭발 시에 발생하는 큰소리, 이른바 폭발음은 공기 중을 전파하는 압력파(blast wave)에 의한 것이고 건물이나 실내 파괴는 그들의 내부압력 상승에 의한 것이다. 그러므로 폭발현상은 압력상승과 불가분하다고 생각해도 된다. (중략)

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ENERGY DECAY ESTIMATES FOR A KIRCHHOFF MODEL WITH VISCOSITY

  • Jung Il-Hyo;Choi Jong-Sool
    • Bulletin of the Korean Mathematical Society
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    • v.43 no.2
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    • pp.245-252
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    • 2006
  • In this paper we study the uniform decay estimates of the energy for the nonlinear wave equation of Kirchhoff type $$y'(t)-M({\mid}{\nabla}y(t){\mid}^2){\triangle}y(t)\;+\;{\delta}y'(t)=f(t)$$ with the damping constant ${\delta} > 0$ in a bounded domain ${\Omega}\;{\subset}\;\mathbb{R}^n$.

High Impedance Fault Detection Based on Wavelet Transform (웨이브렛 변환을 이용한 고저항 사고 검출)

  • Chung, Young-Sik;Kim, Dong-Wook
    • Proceedings of the KIEE Conference
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    • 2008.07a
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    • pp.263-264
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    • 2008
  • A method for high impedance fault(HIF) detection based on wavelet transform is presented in this paper. HIF is detected and classified by obtaining the energy distribution curve from the wavelet coefficients at each level. The energy distribution of each transient disturbance has unique deviation from sinusoidal wave in particular energy level, which is adopted to provide reliable classification of the type of transient.

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