• Title/Summary/Keyword: observed wave data

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Study on the wave resonance-stimultion and receptionfor the BIO-KI (생체 기에 대한 피동공명적인 연구)

  • Ryu Gyeong Ho;Kim Gyeong Cheol;Lee Yong Tae
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.17 no.2
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    • pp.263-274
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    • 2003
  • The present condition of study on the wave-resonance for the bio-KI is observed. And the probroms of reception attendent on the stimulation of wave is observed centering around the sensory organ. The results is as follows: In the wave-resonant stand point, the tendency of studying on KI is showed in the several field all over the world. Because it is originated radionics, the wave-resonant tools of MRA insistenting minute-magnetism-resonance-apparatus need the more severe data in the side of electric circuit. The wave resonance apparatus according to the frequency occurance transmits low-frequency's vibration ratio to the electric stimulating aspect. The wave-water is considered on the application of wave-resonance transcription on the water, and needs the comprehension of torsion-field level. The wave-stimulation of the bio-KI and the reception of the sensory-organ is observed the connection of the sensory-organ and it's corresponding wave. The informations recorded in the wave are distinguished patternly. And the several shaping waves transmit the informations each other through the resonnance. The wave theory is explained the LEE(理) as the wave-pattern and the KI(氣) as the revelation of the patterned-wave in the LEE-KI theory(理氣論), moreover the SHIN(神) as the information of the wave-pattern and the KI as the energy of the wave and the JEUNG(精) as the material of the wave in the JEUNG-KI-SHIN theory(精氣神論). In this point, the study on the wave-resonance of bio-KI is thought that it is significantly in the study method for oriental medicine. The sum of the wave makes the moving body and forms the universe. It means that the several wave patterns gather and form new field. The pattern is a kind of the information and the information is not materially. The information of wave-pattern is the arrangement and the combination of the material source.

Sea State Hindcast for the Korean Seas With a Spectral Wave Model and Validation with Buoy Observation During January 1997

  • Kumar, B. Prasad;Rao, A.D.;Kim, Tae-Hee;Nam, Jae-Cheol;Hong, Chang-Su;Pang, Ig-Chan
    • Journal of the Korean earth science society
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    • v.24 no.1
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    • pp.7-21
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    • 2003
  • The state-of-art third generation wave prediction model WAM was applied to the Korean seas for a winter monsoon period of January 1997. The wind field used in the present study is the global NSCAT-ERS/NCEP blended winds, which was further interpolated using a bi-cubic spline interpolator to fine grid limited area shallow water regime surrounding the Korean seas. To evaluate and investigate the accuracy of WAM, the hindcasted wave heights are compared with observed data from two shallow water buoys off Chil-Bal and Duk-Juk. A detailed study has been carried with the various meteorological parameters in observed buoy data and its inter-dependency on model computed wave fields was also investigated. The RMS error between the observation and model computed wave heights results to 0.489 for Chil-Bal and 0.417 for Duk-Juk. A similar comparison between the observation and interpolated winds off Duk-Juk show RMS error of 2.28 which suggest a good estimate for wave modelling studies.

A Study on the Kinematics of Ocean Waves by Gravity Wave Theory and Stream Function Method (해양파(海洋波)의 운동학(運動學)에 대한 중력파이론(重力波理論)과 Steam Function Method의 비교연구(比較硏究))

  • Y.K.,Bang;I.H.,Chang;H.S.,Choi
    • Bulletin of the Society of Naval Architects of Korea
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    • v.19 no.2
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    • pp.33-39
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    • 1982
  • It is one of the basic problems of naval architecture and ocean engineering how to describe the wave kinematics normally under the assumption of an ideal fluid. At present, there are many wave theories available for design purposes. These can be classified into two groups: One is the analytic theory and the other is the numerical theory. This paper briefly introduces the stream function method of R.G. Dean which belongs to the latter group and shows its numerical evaluations exemplified for two cases: One is applied to observed waves and the other is for design waves. In the former case, the wave profiles are calculated by the stream function method and compared with those of the observed waves and also with the results of R.G. Dean. They show good agreement. In the latter case, the wave kinematics and wave loads on a column of diameter 1m are calculated by the stream function method and these are compared with those resulted from the 5th-order gravity wave theory. As a result of comparison the values by the stream function method are slightly larger than those by the 5th-order gravity wave theory but the difference are negligible. From this it is concluded that the stream function method is very useful. And as characteristics of the numerical theories, the stream function method of R.G. Dean can be easily extended to the higher order terms and can include easily the current velocity and the pressure distribution on the free surface. In addition, when the data of observed wave profile are given, this method can reproduced the observed wave profile as closely as possible so that this method seems to describe the ocean wave more realistically. And from standpoint of a mathematical principle the stream function method exactly satisfies the kinematic free-surface boundary condition.

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Simulation of Heat Health Alert System Using Meteorological Data Observed by Automatic Weather Systems in Seoul, Korea

  • Kim, Ji-Young;Kim, Jung-Ok;Park, Seung-Yong;Yu, Ki-Yun
    • Proceedings of the KSRS Conference
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    • 2007.10a
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    • pp.134-137
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    • 2007
  • In this paper the heat health alert system, which is operated this year by way of showing an example, is a simulator linked to the Geographic Information System (GIS), and it uses meteorological data that are observed at Automatic Weather Systems (AWSs) in Seoul, Korea. Simulation results show that it is possible to use meteorological data observed by AWSs when the Korea Meteorological Administration (KMA) has issued alerting the public to the threat of heat waves, and to connect meteorological data to spatial data when the KMA offers local forecasts and weather-related information. However, most AWSs that were installed to manage urban disasters do not measure humidity, so general humidity is used in all districts. Therefore, to issue heat wave warnings about different localities on a small scale, we will study how to complement this problem and to examine the accuracy of data observed at AWS in the future.

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Analysis of Wave Transmission Characteristics on the TTP Submerged Breakwater Using a Parabolic-Type Linear Wave Deformation Model

  • Jeong, Jin-Hwan;Kim, Jin-Hoon;Lee, Jung-Lyul
    • Journal of Ocean Engineering and Technology
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    • v.35 no.1
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    • pp.82-90
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    • 2021
  • Owing to the advantages of assuring the best views and seawater exchange, submerged breakwaters have been widely installed along the eastern coast of Korea in recent years. It significantly contributes to promoting the advancement of shorelines by partially inhibiting incident wave energy. Observations were carried out by a pressure-type wave gauge in the Bongpo Beach to evaluate the coefficients of wave transmission via a submerged breakwater, and the results obtained were compared with those of existing conventional equations on the transmission coefficient derived from hydraulic experiments. After reviewing the existing equations, we proposed a transmission coefficient equation in terms of an error function. Although it exhibited robust relationships with the crest height and breaking coefficient, deviations from the observed data were evident and considered to be triggered by the difference in the incident wave climate. Therefore, in this study, we conducted a numerical experiment to verify the influence of wave period on the coefficients of wave transmission, in which we adopted a parabolic-type mild-slope equation model. Consequently, the deviation from calculated results appears to practically cover all deviation range in the observed data. The wave period and direction of the incident wave increased, the transmission coefficient decreased, and the wave direction was determined to demonstrate a relatively significant influence on the transmission coefficient. It was inferred that this numerical study is expected to be used practically in evaluating the design achievement of the submerged breakwater, which is adopted as a countermeasure to coastal beach erosion.

Optimization of SWAN Wave Model to Improve the Accuracy of Winter Storm Wave Prediction in the East Sea

  • Son, Bongkyo;Do, Kideok
    • Journal of Ocean Engineering and Technology
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    • v.35 no.4
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    • pp.273-286
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    • 2021
  • In recent years, as human casualties and property damage caused by hazardous waves have increased in the East Sea, precise wave prediction skills have become necessary. In this study, the Simulating WAves Nearshore (SWAN) third-generation numerical wave model was calibrated and optimized to enhance the accuracy of winter storm wave prediction in the East Sea. We used Source Term 6 (ST6) and physical observations from a large-scale experiment conducted in Australia and compared its results to Komen's formula, a default in SWAN. As input wind data, we used Korean Meteorological Agency's (KMA's) operational meteorological model called Regional Data Assimilation and Prediction System (RDAPS), the European Centre for Medium Range Weather Forecasts' newest 5th generation re-analysis data (ERA5), and Japanese Meteorological Agency's (JMA's) meso-scale forecasting data. We analyzed the accuracy of each model's results by comparing them to observation data. For quantitative analysis and assessment, the observed wave data for 6 locations from KMA and Korea Hydrographic and Oceanographic Agency (KHOA) were used, and statistical analysis was conducted to assess model accuracy. As a result, ST6 models had a smaller root mean square error and higher correlation coefficient than the default model in significant wave height prediction. However, for peak wave period simulation, the results were incoherent among each model and location. In simulations with different wind data, the simulation using ERA5 for input wind datashowed the most accurate results overall but underestimated the wave height in predicting high wave events compared to the simulation using RDAPS and JMA meso-scale model. In addition, it showed that the spatial resolution of wind plays a more significant role in predicting high wave events. Nevertheless, the numerical model optimized in this study highlighted some limitations in predicting high waves that rise rapidly in time caused by meteorological events. This suggests that further research is necessary to enhance the accuracy of wave prediction in various climate conditions, such as extreme weather.

Growth of Wind Waves with Fetch in the Sea of Japan under Winter Monsoon Investigated using Data from Satellite Altimeters and Scatterometer

  • Ebuchi, Naoto
    • Proceedings of the KSRS Conference
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    • 1998.09a
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    • pp.31-36
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    • 1998
  • By using wind vectors observed by NSCAT and significant wave heights observed by TOPEX/POSEIDON and ERS-2 altimeters, one-dimensional fetch growth of wind waves Is investigated under conditions of strong wind and high waves of the East Asian winter monsoon. The evolution of fetch-limited wind waves can be observed by the altimeters along the ground tracks. The fetch is estimated by using vector wind field observed by NSCAT. The derived growth characteristics of wind waves are compared with empirical relationships between the non-dimensional fetch and significant wave height proposed by previous studies. Good agreement with the empirical fetch graph formula normalized by the friction velocity is discemible, while the formulas normalized by the wind speed at a height of 10 m tend to underestimate the wave height under such severe conditions of high wind and very long fetch.

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Extreme and Freak Wave Characteristics in the Coastal Writers of Korean Peninsula (한국 연안의 극히 파랑환경과 Freak Wave의 특성에 관한 연구)

  • 류청로;윤홍주
    • Journal of Environmental Science International
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    • v.2 no.3
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    • pp.235-243
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    • 1993
  • Extreme environments and freak wave characteristics in the coastal waters of Korean Peninsula are analyzed using the observed wave data. Freak wave has been intensely emphasized as an important environmental force parameter in several recent research works. However, the mechanism and occurrence probability of freak wave are not clarified. The aims of this study we: to summarize the distribution of extreme environment for wind waves, and to find occurrence probability of freak wave in the coastal waters of Korean Peninsula. These extreme sea conditions are discussed by applying extreme value analysis method, and the statistic characteristics are summarized which can be used to the design and analysis of coastal structures. The mechanism and the occurrence probability of freak wave are also discussed in detail using wave parameters in considered with wave deformation in the coastal waters. Key Words : extreme wave, freak wave, extreme analysis, design wave, probability density.

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Research on Wind Waves Characteristics by Comparison of Regional Wind Wave Prediction System and Ocean Buoy Data (지역 파랑 예측시스템과 해양기상 부이의 파랑 특성 비교 연구)

  • You, Sung-Hyup;Park, Jong-Suk
    • Journal of Ocean Engineering and Technology
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    • v.24 no.6
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    • pp.7-15
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    • 2010
  • Analyses of wind wave characteristics near the Korean marginal seas were performed in 2008 and 2009 by comparisons of an operational wind wave forecast model and ocean buoy data. In order to evaluate the model performance, its results were compared with the observed data from an ocean buoy. The model used in this study was very good at predicting the characteristics of wind waves near the Korean Peninsula, with correlation coefficients between the model and observations of over 0.8. The averaged Root Mean Square Error (RMSE) for 48 hrs of forecasting between the modeled and observed waves and storm surges/tide were 0.540 m and 0.609 m in 2008 and 2009, respectively. In the spatial and seasonal analysis of wind waves, long waves were found in July and September at the southern coast of Korea in 2008, while in 2009 long waves were found in the winter season at the eastern coast of Korea. Simulated significant wave heights showed evident variations caused by Typhoons in the summer season. When Typhoons Kalmaegi and Morakot in 2008 and 2009 approached to Korean Peninsula, the accuracy of the model predictions was good compared to the annual mean value.

Estimation of Wave Power in Korean Coastal Waters (파랑에너지 해석 및 가용량 평가 연구)

  • 김현주;최학선;김선경
    • Journal of Ocean Engineering and Technology
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    • v.12 no.1
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    • pp.107-112
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    • 1998
  • The purpose of this study is to analyze the amount of available wave power and its characteristics related to the development of apractical system for ocean wave energy conversion in Korean coastal waters. The analysis method of wave power was established through comparison between theory and numerical simulation of deep sea wave by Inverse Fourier Transform with random phase method. Based on the results of comparison, wave power was estimated by use of data set from observed offshore and coastal waves and hindasted deep sea waves around the Korean peninsula. Annual mean wave power is estimated as about 1.8 ~ 7.0 kW for every metre of wave frontage at East sea, 1.5~5.3 kW at South sea and 1.0 ~ 4.1 kW at West sea, respectively. Mean wave power along deep sea front of coastal waters of Korea amounts to about 4.7 GW. Regional distribution and seasonal variation of wave power were discussed to develop practical utilization system of wave power of not so high grade of available wave power.

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