• Title/Summary/Keyword: Wave Action

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Action Observation and Cortical Connectivity: Evidence from EEG Analysis

  • Kim, Sik-Hyun;Cho, Jeong-Sun
    • The Journal of Korean Physical Therapy
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    • v.28 no.6
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    • pp.398-407
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    • 2016
  • Purpose: The purpose of this study was to examine the changes in electroencephalogram (EEG) coherence and brain wave activity for first-person perspective action observation (1AO) and third-person perspective action observation (3AO) of healthy subjects. Methods: Thirty healthy subjects participated in this study. EEG was simultaneously recorded during the Relax period, the 1AO, and the 3AO, with event-related desynchronization (ERD) and coherence connectivity process calculations for brain wave (alpha, beta and mu) rhythms in relation to the baseline. Results: Participants showed increased coherence in beta wave activity in the frontal and central areas (p<0.05), during the 1AO using right-hand activity. Conversely, the coherence of the alpha wave decreased statistically significantly decreased in the frontocentral and parieto-occipital networks during the observation of the 1AO and the 3AO. The ERD values were larger than 40% for both central regions but were slightly higher for the C4 central region. The high relative power of the alpha wave during 1AO and 3AO was statistically significantly decreased in the frontal, central, parietal, and occipital regions. However, the relative power of the beta wave during 1AO and 3AO was statistically significantly increased in the parietal and occipital regions. Especially during 1AO, the relative power of the beta wave in the C3 area was statistically significantly increased (p<0.05). Conclusion: These findings suggest that 1AO and 3AO action observations are relevant to modifications of specific brain wave coherence and ERD values. EEG cortical activity during action observation may contribute to neural reorganization and to adaptive neuroplasticity in clinical intervention.

Cochlear Implant of the Hair-Cell Damaged Cats (모세포 손상 가묘에 대한 Cochlear Implant)

  • 장인원;김성남;양한모;최윤호;조용범
    • Proceedings of the KOR-BRONCHOESO Conference
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    • 1978.06a
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    • pp.9.1-10
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    • 1978
  • Recently the authors have observed various wave-forms by insertion of induction coil into the scala tympani as well as attached outer device in the outside of the body in damaged hair cells of the cats. In the cochlear nerve. action potential indicated different polarities induced by examination of the bundle of the cochlear nerve fibers. Impulse wave-form as a result of excitation of cohlear nerve fibers showed bipolar wave-form such as negative 1 and positive 1. Therefore action potential showed also bipolar wave-form as above mentioned. We can obtained suitable response with above mentioned outer and inner device as an exact oscillogram.

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A Study on the Numerical Calculation for Wind Waves During the Passage of Typhoon 'Memi' (태풍 '매미' 내습시 파랑선정에 관한 기초적 연구)

  • LEE GYONG-SEON;KIM HONG-JIN;YOON HAN-SAM;RYU CHEONG-RO
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2004.05a
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    • pp.229-234
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    • 2004
  • A Typhoon wave is generated by wind fields during the Passage of Typhoon. Transporting wind field makes wind wave and swell in the open sea, and then, those wave components are transported in the shallow water. Typhoon waves in the shallow water is generated by Typhoon wind field and incident wave. Bisides, Incident waves to the shallow water are deformated by topographic conditions. This paper estimated the analysis of the Typhoon waves by wind fields and incident waves according to wave action balance equation model. As the result of wave numerical experiment, wave field during the passage of Typhoon 'Memi' in the shallow water is strongly effect by wind fields. Wave action balance equaion can be partially used for Typhoon wave simulations.

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Breakwater Design against Flood and Typhoon (풍수해에 대비한 방파제 설계기법)

  • 김인호;유동훈
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.16 no.2
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    • pp.103-107
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    • 2004
  • Empirical equation has been developed by employing the new non-dimensional physical number 'wave action slope' for the estimation of breakwater armor weight. Van der Meer(1987) introduced Iribarren number for the same purpose, but his equation shows very different trend of distribution with the condition of Iribarren number. On the other hand the equation related with wave action slope keeps the same trend of distribution over the whole region. When the parameter is related to the Iribarren number, the equation of wave action slope has a very high accuracy.

The Effects of Tunable Helmholtz Resonators on the Volumetric Efficiency in a Multi-cylinder Diesel Engine (가변 헬름홀츠 공진기가 다기통 디젤기관의 체적효율에 미치는 영향)

  • Kang, H.Y.;Koh, D.K.;Ahn, S.K.
    • Journal of Power System Engineering
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    • v.9 no.3
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    • pp.26-32
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    • 2005
  • The volumetric efficiency is significantly affected by the behavior of pressure wave in induction system and exhaust pipe. By the motion of the piston, there exist pressure fluctuation in induction system which produce waves. Waves are propagated along a pipe bi-directional as they propagated through it, making compression wave and rare-faction(expansion) wave. These wave phenomena can affect to the volumetric efficiency. As a method of improvement of the volumetric efficiency, fuel economy and pollutant emission reduction particularly in low engine speeds, a side-branch additional tunable helmholtz resonator on the secondary pipe of intake system is proposed by use of their acoustic vibrations. Some of results are presented which deal with their physical phenomena for the wave action of intake system in a four-stroke three cylinders diesel engine.

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Analysis and Quantification of Seawater Infiltration by Wave Action in Coastal Zone (연안해역에서 파도에 의한 해수 침투이론의 비교와 정량화)

  • Cheong Cheong-jo;Choi Doo-hyoung;Kim Tae-keun;Okada Mitsumasa
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.4 no.4
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    • pp.3-11
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    • 2001
  • To know the seawater infiltration into tidal flat sediment in coastal area is very important, because it is significantly correlated with the infiltration and transportation of pollutants in soil, the supply of dissolved oxygen, nutrients and organic matter to benthic organisms for survival of benthic organisms and the seawater purification. So, we set up purpose to clarify the infiltration behavior of seawater by wave action in tidal flat, to clear the effects of slope of tidal flat and breaking wave height on seawater infiltration and to quantify the infiltration volume of seawater. For purpose, the seawater infiltration was studied with visualization method by using coloring tracer and transparent glass beads replaced as natural sediment in model tidal flat. Specific conclusions derived from this study are as follows. The semi-circular type infiltration of seawater by wave action into saturated sediment was a new infiltration behavior that was not considered in previous studies. The infiltration rate of seawater was increased with increasing of breaking wave height and slope of tidal flat. However, the effects of the slope was bigger than that of breaking wave height on seawater infiltration into tidal flat sediments. It was possible to calculate the infiltration volume of seawater by wave action in natural tidal flat sediment and in fields. Therefore, we can point out that wave action play an important role in the supply of dissolved oxygen, nutrients and organic matter to benthic organisms, transportation or diffusion of pollutants and seawater purification. So, we hope to be studied the supply of food to benthic organism, pollutant transport and seawater purification on the base of these results.

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Analysis of Wave Data and Estimation of Littoral Drifts for the Eastern Coast of Korea (한국동해안의 파랑 자료 분석 및 표사량 추정)

  • 김아리;이정열;최병호
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.13 no.1
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    • pp.18-34
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    • 2001
  • Statistical analysis oflong-tenn wave data resulted from HYPA(HYbrid PArametric wave model) for the eastern coast of Korea was performed. Subsequently a simple approach for predicting the global annual and seasonal littoral drifts has been derived to estimate littoral sediment budget.

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Computational study of the wave propagation in three-dimensional human cardiac tissue

  • Kwon, Soon-Sung;Im, Uk-Bin;Kim, Ki-Woong;Lee, Yong-Ho;Shim, Eun-Bo
    • International Journal of Vascular Biomedical Engineering
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    • v.3 no.1
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    • pp.23-29
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    • 2005
  • We developed a three dimensional cardiac tissue model based on human cardiac cell and mono-domain approximation for action potential propagation. The human myocyte model proposed by ten Tusscher et al. (TNNP model) (2004) for cell electrophysiology and a mono-domain method for electric wave propagation are used to simulate the cardiac tissue propagation mechanism using a finite element method. To delineate non-homogeneity across cardiac tissue layer, we used three types of cardiac cell models. Ansiotropic effect of action potential propagation is also considered in this study. In this 3D anisotropic cardiac tissue with three cell layers, we generated a reentrant wave using S1-S2 protocol. Computational results showed that the reentrant wave was affected by the anisotropic properties of the cells. To test the reentrant wave under pathological state, we simulated a hypertopic model with non-excitable fibroblasts in stochastic manner. Compared with normal tissue, the hypertropic tissue result showed another center of reentrant wave, indicating that the wave pattern can be more easily changed from regular with a concentric focus to irregular multi-focused reentrant waves in case of patients with hypertrophy.

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Empirical Equation of Wave Run-up Height (도파고 경험식)

  • Yoo Dong Hoon;Kim In Ho
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.16 no.4
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    • pp.233-240
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    • 2004
  • For the development of empirical equation of run-up height, a new surf parameter called' wave action slope' $S_x$ is introduced. Approximate equation has been produced for each band of water depth for the computation of wave run-up height using the laboratory graph of Saville(1958). On the other hand using the laboratory data of Ahrens(1988) and Mase(1989), empirical equations of run-up height have been developed for the general application with considering roughness effect covering a wide range of water depth and wall slope. When Mase tried to relate the run-up height to the Iribarren number, nonlinear relation has been obtained and hence the empirical equation has a power law. But when the wave action slope is adopted as a major factor for the estimation of run-up height the empirical equation shows a linear relationship with very good correlation for the wide range of water depth and wall slope.