• Title/Summary/Keyword: mountain wave

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Flow Regimes of Continuously Stratified Flow over a Double Mountain (두 개의 산악 위에서의 연속적으로 성층화된 흐름의 흐름 체계)

  • Han, Ji-Young;Kim, Jae-Jin;Baik, Jong-Jin
    • Atmosphere
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    • v.17 no.3
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    • pp.231-240
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    • 2007
  • The flow regimes of continuously stratified flow over a double mountain and the effects of a double mountain on wave breaking, upstream blocking, and severe downslope windstorms are investigated using a mesoscale numerical model (ARPS). According to the occurrence or non-occurrence of wave breaking and upstream blocking, three different flow regimes are identified over a double mountain. Higher critical Froude numbers are required for wave breaking and upstream blocking initiation for a double mountain than for an isolated mountain. This means that the nonlinearity and blocking effect for a double mountain is larger than that for an isolated mountain. As the separation distance between two mountains decreases, the degree of flow nonlinearity increases, while the blocking effect decreases. A rapid increase of the surface horizontal velocity downwind of each mountain near the critical mountain height for wave breaking initiation indicates that severe downslope windstorms are enhanced by wave breaking. For the flow with wave breaking, the numerically calculated surface drag is much larger than theoretically calculated one because the region with the maximum negative perturbation pressure moves from the top to the downwind slope of each mountain as the internal jump propagating downwind occurs.

Effect of pulse-wave factors in Middle Aged Women by Mountain Cultivated Ginseng Pharmacopuncture Original Articles (산삼 약침이 정상 중년여성의 맥파요인에 미치는 영향)

  • Park, Sang-Wook;Kim, Yi-Soon;Hwang, Won-Deok;Kim, Gyeong-Cheol
    • Journal of Pharmacopuncture
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    • v.14 no.1
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    • pp.35-49
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    • 2011
  • Objectives: The aim of this experiment is to know about Effect of pulse-wave factors in Middle Aged Women by Mountain Cultivated Ginseng Pharmacopuncture. Methods: First 20 Middle Aged women are diagnosed by pulse diagnosis, and then Mountain Cultivated Ginseng Pharmacopuncture(1 injection 20cc) were injected. 30 minutes later, pulse diagnosis again performed. As a result, method of one-group pretest-posttes design were used for evaluation. Results: T(Total pulse cycle) time statistically significant increased on both left and right chon, kwan, cheok. T4 time statistically significant increased on both left and right chon, kwan, cheok. T4-T1/T indexs except left cheokmaek, Right cheokmaek observation area decreased significantly in four sites. Wm(indicating high pressure retention time) indexs increased significantly in the five sites were observed except right chon maek. Conclusions: Effect of pulse-wave factors in Middle Aged Women by Mountain Cultivated Ginseng Pharmacopuncture increased T, T4, Wm and decreased T4-T1/T indexs. The results of this experiment, Mountain Cultivated Ginseng Pharmacopuncture induced to increase the Pulse-wave's stability and strength.

A Numerical Study on the Karman Vortex Generated by Breaking of Mountain Wave

  • Sung-Dae Kang;Fujio Kimura
    • Journal of Environmental Science International
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    • v.1 no.2
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    • pp.105.2-117
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    • 1992
  • The formation mechanism of the vortex streets in the lee of the mountain Is Investigated by a three-dimensional numerical model. The model is based upon the hydrostatic Boussinesq equations in which the vertical turbulent momentum flux is estimated by a turbulence parameterization scheme, but the horizontal viscosity is assumed to be constant. The results show that Karman vortex streets can form even without surface friction in a constant ambient flow with uniform stratification. The vortex formation is related to breaking of the mountain wave, which depends on the Froude number (Fr). In the case of a three-dimensional bell-shaped mountain, the wave breaking occurs when Fr is less than about 0.8, while a barman vortex forms when Fr is less than about 0.22. Vortex formation also depends on Reynolds number, which is estimated from the horizontal diffusivity. The vortex formation can be explained by the wave saturation theory given by Lindzen (1981) with some modification. Simulations in this study show that in the case of Karman vortex formation the momentum flux in the lower level is much larger than the saturated momentum flux, whereas it is almost equal to the saturated momentum at the upper levels as expected from the saturation theory. As a result, large flux divergence is produced in the lower layer, the mean flow is decelerated behind the mountain, and the horizontal wind shear forms between unmodified ambient wind. The momentum exchange between the mean flow and the mountain wave is produced by the turbulence within a breaking wave. From the result, well developed vortices like Karman vortex can be formed. . The results of the momentum budget calculated by the hydrostatic model are almost the same as nonhydrostatic results as long as horizontal scale of the mountain is 10 km. A well developed barman vortex similar to the hydrostatic one was simulated in the nonhydrostatic case. Therefore, we conclude that the hydrostatic assumption is adequate to investigate the origin of the Km8n vortex from the viewpoint of wave breaking.

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A Numerical Study on the Karman Vortex Generated by Breaking of Mountain Wave

  • Kang Sung-Dae;Kimura Fujio
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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    • v.1 no.2
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    • pp.105-117
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    • 1997
  • The formation mechanism of the vortex streets in the lee of the mountain is investigated by a three-dimensional numerical model. The model is based upon the hydrostatic Boussinesq equations in which the vertical turbulent momentum flux is estimated by a turbulence parameterization scheme, but the horizontal viscosity is assumed to be constant. The results show that Karman vortex streets can form even without surface friction in a constant ambient flow with uniform stratification. The vortex formation is related to breaking of the mountain wave, which depends on the Froude number (Fr). In the case of a three-dimensional bell-shaped mountain, the wave breaking occurs when Fr is less than about 0.8, while a Karman vortex forms when Fr is less than about 0.22. Vortex formation also depends on Reynolds number, which is estimated from the horizontal diffusivity. The vortex formation can be explained by the wave saturation theory given by Lindzen (1981) with some modification. Simulations in this study show that in the case of Karman vortex formation the momentum flux in the lower level is much larger than the saturated momentum flux whereas it is almost equal to the saturated momentum at the upper levels as expected from the saturation theory. As a result, large flux divergence is produced in the lower layer, the mean flow is decelerated behind the mountain, and the horizontal wind shear forms between unmodified ambient wind. The momentum exchange between the mean flow and the mountain wave is produced by the turbulence within a breaking wave. From the result, well developed vortices like Karman vortex can be formed. The results of the momentum budget calculated by the hydrostatic model are almost the same as nonhydrostatic results as long as horizontal scale of the mountain is 10 km. A well developed Karman vortex similar to the hydrostatic one was simulated in the nonhydrostatic case. Therefore, we conclude that the hydrostatic assumption is adequate to investigate the origin of the Karman vortex from the viewpoint of wave breaking.

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Effect of Mountain Cultivated Ginseng Pharmacopuncture on Heart Rate Variability(HRV), Pulse Wave Velocity(PWV) in Middle Aged Women (산양삼약침이 정상 중년여성의 심박변이도(HRV), 맥파속도(PWV)에 미치는 영향)

  • Park, Sang-Wook;Kim, Yi-Soon;Hwang, Won-Deok;Kim, Gyeong-Cheol
    • Journal of Acupuncture Research
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    • v.28 no.2
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    • pp.97-105
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    • 2011
  • Objectives : The aim of this experiment is to know the effect of mountain cultivated ginseng pharmacopuncture on heart rate variability(HRV), pulse wave velocity(PWV) in middle aged women. Methods : We investigated on 20 healthy Middle Aged women volunteers. First, we measured their heart rate variability(HRV), pulse wave velocity(PWV) and then mountain cultivated ginseng pharmacopuncture 20cc were injected on them. After 30 minutes, we measured heart rate variability(HRV), pulse wave velocity(PWV) again. As a result, method of one-group pretest-posttes design were used for evaluation. Results : 1. In HRV, MeanHRV is significantly decreased from 69.15 to 63.34 after injection. 2. MeanRR is significantly increased from 877.20 to 962.10 after injection. SDNN is significantly increased from 32.56 to 41.34 after injection. 3. PNN50 is significantly decreased after injection. RNSSD, SDSD, TP, VLF is significantly increased after injection. 4. Stress resistance ability is significantly increased from 37.55 to 44.60 after injection. 5. In PWV, E-R, E-L, H-R, H-L is significantly decreased after injection. Conclusions : Effect of mountain cultivated ginseng pharmacopuncture on heart rate variability(HRV) increased adaptability of autonomic nervous system and on pulse wave velocity(PWV) decreased arterial stiffness.

Effect of Heart Rate Variability, Pulse Wave Velocity in Women of Breast Cancer Patients Care by Mountain Cultivated Ginseng Pharmacopuncture (산양삼(山養蔘) 약침(藥鍼)이 유방암절제술 여성의 심박변이도, 맥파전달속도에 미치는 영향)

  • Kim, Gyeong-Cheol;Park, Sang-Wook;Kim, Yi-Soon
    • The Journal of the Society of Korean Medicine Diagnostics
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    • v.15 no.3
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    • pp.245-260
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    • 2011
  • Objectives: The aim of this experiment is to know the effect of Mountain Cultivated Ginseng Pharmacopuncture on Heart Rate Variability (HRV), Pulse wave velocity (PWV) in Middle Aged Women. Methods: We investigated on 40 women of breast cancer patients. First, we measured their Heart Rate Variability(HRV), Pulse wave velocity (PWV) and then Mountain Cultivated Ginseng Pharmacopuncture $20m{\ell}$ were injected on them. After 30 minutes, we measured Heart Rate Variability(HRV), Pulse wave velocity(PWV) again. As a result, method of non-equivalent control group non-synchronized design were used for evaluation. Results: In HRV, Mean HRV is significantly decreased from 69.15 to 63.34 after injection. Mean RR is significantly increased from 877.20 to 962.10 after injection. SDNN is significantly increased from 32.56 to 41.34 after injection. PNN50 is significantly decreased after injection. RNSSD, SDSD, TP, VLF is significantly increased after injection. Stress Resistance ability is significantly increased from 37.55 to 44.60 after injection. And In PWV, E-R, E-L, H-R, H-L is significantly decreased after injection. Conclusions: Effect of Mountain Cultivated Ginseng Pharmacopuncture on Heart Rate Variability (HRV) increased adaptability of autonomic nervous system and on Pulse wave velocity (PWV) decreased arterial stiffness.

TWO JUMPING NONLINEAR TERMS AND A NONLINEAR WAVE EQUATION

  • Jung, Tacksun;Choi, Q-Heung
    • Journal of the Chungcheong Mathematical Society
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    • v.22 no.4
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    • pp.675-687
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    • 2009
  • We find the multiple nontrivial solutions of the equation of the form $u_{tt}-u_{xx}=b_1[(u+1)^{+}-1]+b_2[(u+2)^{+}-2]$ with Dirichlet boundary condition. Here we reduce this problem into a two-dimensional problem by using variational reduction method and apply the Mountain Pass theorem to find the nontrivial solutions.

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A Simple Simulation of Parabola-Shaped Clouds in the Lee of a Low Bell-Shaped Mountain Using the ARPS

  • Lee, Seung-Jae;Lee, Hwa-Woon;Kang, Sung-Dae
    • Journal of Environmental Science International
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    • v.16 no.5
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    • pp.541-548
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    • 2007
  • A three-dimensional linear model and the Advanced Regional Prediction System (ARPS) were used to simulate parabola-shaped disturbances and clouds in the lee of a bell-shaped mountain. The ARPS model was compared in the x-y plane against the linear model's analytic solution. Under similar conditions with the linear theory, the ARPS produced well-developed parabola-shaped mountain disturbances and confirmed the features are accounted for in the linear regime. A parabola-shaped cloud in the lee of an isolated bell-shaped mountain was successfully simulated in the ARPS after 6 hours of integration time with the prescribed initial and boundary conditions, as well as a microphysical scheme.

The Experimented MF Propagation Modeling for Mountain geography (산악지형에 적합한 경험적 중파 전파 모델링)

  • Kim, Bum-Chang;Kwon, Se-Woong;Yoon, Young-Joong
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2003.11a
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    • pp.18-22
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    • 2003
  • In this thesis, Middle frequency wave propagation modeling is studied for the varies mountain geography the experimented middle frequency propagation model is researched in a shot time to analyze the broad area that consists of mountains. Due to the Sommerfeld - Norton model which is used broadly the middle frequency propagation model to analyze the broad area in a short time is proposed introducing the newly attenuation parameter of the experimental results on the basis of actual experiments at the mountain configuration regardless of the area of mountain, plane, sea etc.

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Near-field Performance Analysis of LW-TLM Antenna for propagation obstacle (장파대역 TLM 안테나의 전파 장애물에 의한 근거리장 성능 분석)

  • Kim, Young-Wan
    • Journal of IKEEE
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    • v.24 no.4
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    • pp.1064-1068
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    • 2020
  • For LW-TLM antenna of 65 kHz, Near-field propagation characteristics due to wave propagation obstacle are analyzed in this paper. The simulation modeling for propagation effects are based on the model of actual LW-TLM antenna which utilizes the frequency of 65 kHz, and the model expressed as propagation obstacle at a mountain height and a proximity of antenna and mountain. The near-field performance are analyzed based on the parameters of simulation model. In case of a normal mountain height and distance between the adjacent mountain and antenna site, a field strength change of about 1.7 dB has occurred. Above the constant distance of propagation obstacle and antenna, the wave propagation characteristics of disregarding the effects of propagation obstacle are shown. The results of this paper can be used to design and build a transmitting antenna site with 65 kHz operating frequency.