• Title/Summary/Keyword: Wave statistics

Search Result 154, Processing Time 0.026 seconds

Artificial Generation of Seismic Wave Reflecting Information (위상특성을 반영한 인공지진파 작성)

  • 연관희
    • Proceedings of the Earthquake Engineering Society of Korea Conference
    • /
    • 2000.10a
    • /
    • pp.91-97
    • /
    • 2000
  • Once a response spectrum is estimated for the site, if there is a need of generating realistic earthquakes time histories considering seismic sources and path effects, one alternative is to use statistical phase characteristics based on real earthquake records other than assuming arbitrary duration and envelope curves. In this study, statistics of group delay times derived from Japanese strong earthquake data were used for phase generation to fully capture the stochastic property of earthquakes. The result shows that simulated earthquake time histories can be generated according to earthquake magnitude and distances with target response spectrum.

  • PDF

Sea Environmental Design Criteria for Coastal and Offshore Structures

  • Liu, Defu
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
    • /
    • 1996.10a
    • /
    • pp.19-22
    • /
    • 1996
  • Extreme sea statistics and combinations of environmental events or response for structures are very important problem in performance evaluation and design of coastal and Offshore structures. A probabilistic method is developed that leads to the combination of Typhoon (Hurricane) or winter storm induces winds, waves, currents and surge for a generic site. The traditional recommendation for the fixed structures is a combination of the 100 years maximum wave height with the 100 years wind and current. (omitted)

  • PDF

Statistical Analysis of Lightning-Induced Voltages on Subscriber Telecommunication Lines in Korea

  • Oh, Ho-Seok;Park, Dong-Chul
    • Journal of electromagnetic engineering and science
    • /
    • v.8 no.4
    • /
    • pp.148-152
    • /
    • 2008
  • This paper describes the characteristics of lightning-induced voltages on subscriber telecommunication lines in Korea. Lightning parameters such as peak voltage, rise time, decay time, and steepness of the wave front were statistically analyzed from the measured results obtained using a waveform memory system. An induced voltage measurement system was also developed and installed at 286 sites in Korea to collect the induced voltage data. The distributions of lightning-induced voltages were also analyzed using these data.

The Effects of Aroma Foot Reflex Massage on Mood States and Brain Waves in Women Elderly with Osteoarthritis (아로마 발반사 마사지가 골관절염 여성노인의 기분상태와 뇌파에 미치는 효과)

  • Kim, In Sook;Yang, Hee Jeong;Im, Eun Seon;Kang, Hee Young
    • Korean Journal of Adult Nursing
    • /
    • v.25 no.6
    • /
    • pp.644-654
    • /
    • 2013
  • Purpose: The purpose of this study was to examine the effects of aroma foot reflexology massage on mood states specifically depression and brain waves of elderly women with osteoarthritis. Methods: The study was a nonequivalent control group non-synchronized design. The participants were 62 elderly women with osteoarthritis. The instruments were the Korean-Profile of Mood States-Brief for mood states and 8-channel EEG (Electroencephalogram) system for brain waves. Data were collected from March to May, 2012. Twenty-six participants were assigned to the treatment group and twenty-six to the comparison group. The data were analyzed using SPSS/WIN 17.0 version program, and included descriptive statistics, t-test, and ANCOVA. The intervention was conducted three times a week for two weeks. Results: There were significantly improvement in reported depression. s. Brain waves (EEG) increased significantly in F3, T3 of ${\alpha}$ wave and in F4, T3, and P4 of ${\beta}$ wave between the two groups. Conclusion: Aroma foot reflexology massage can be utilized as an effective intervention to decrease depression of mood states, increase of ${\alpha}$, and ${\beta}$ brain wave on woman elderly with osteoarthritis.

Numerical study on the performance of semicircular and rectangular submerged breakwaters

  • Barzegar, Mohammad;Palaniappan, D.
    • Ocean Systems Engineering
    • /
    • v.10 no.2
    • /
    • pp.201-226
    • /
    • 2020
  • A systematic numerical comparative study of the performance of semicircular and rectangular submerged breakwaters interacting with solitary waves is the basis of this paper. To accomplish this task, Nwogu's extended Boussinesq model equations are employed to simulate the interaction of the wave with breakwaters. The finite difference technique has been used to discretize the spatial terms while a fourth-order predictor-corrector method is employed for time discretization in our numerical model. The proposed computational scheme uses a staggered-grid system where the first-order spatial derivatives have been discretized with fourth-order accuracy. For validation purposes, five test cases are considered and numerical results have been successfully compared with the existing analytical and experimental results. The performances of the rectangular and semicircular breakwaters have been examined in terms of the wave reflection, transmission, and dissipation coefficients (RTD coefficients) denoted by KR, KT, KD. The latter coefficient KD emerges due to the non-energy conserving KR and KT. Our computational results and graphical illustrations show that the rectangular breakwater has higher reflection coefficients than semicircular breakwater for a fixed crest height, but as the wave height increases, the two reflection coefficients approach each other. un the other hand, the rectangular breakwater has larger dissipation coefficients compared to that of the semicircular breakwater and the difference between them increases as the height of the crest increases. However, the transmission coefficient for the semicircular breakwater is greater than that of the rectangular breakwater and the difference in their transmission coefficients increases with the crest height. Quantitatively, for rectangular breakwaters the reflection coefficients KR are 5-15% higher while the diffusion coefficients KD are 3-23% higher than that for the semicircular breakwaters, respectively. The transmission coefficients KT for rectangular breakwater shows the better performance up to 2.47% than that for the semicircular breakwaters. Based on our computational results, one may conclude that the rectangular breakwater has a better overall performance than the semicircular breakwater. Although the model equations are non-dissipative, the non-energy conserving transmission and reflection coefficients due to wave-breakwater interactions lead to dissipation type contribution.

A Study on the Relationship between the Korean Wave, Preference and Recognition of Korean Cuisine among Chinese (중국 내 한류, 한국음식 인지 및 한국음식 선호도에 관한 연구)

  • Jeon, Do Hyun
    • Journal of the Korean Society of Food Culture
    • /
    • v.34 no.3
    • /
    • pp.268-276
    • /
    • 2019
  • This study separated different factors into the Korean Wave and Korean health food according to the interest in Korean culture among the Chinese living in China. We then conducted a two-step cluster analysis with gender, marriage status, academic background, interest in Korean culture, command of the Korean language and the status of having visited Korea as variables. The subjects were split into a Korean wave-preferring group, highly interested in Korean food as health food group and a low interested group according to clusters, and we then investigated for preference differences for 20 Korean food dishes. Between these two groups the statistics indicated a significant influence with a level p<0.001 for Bulgogi, Bibimbap, Kimchi, Galbi-tang, Galbi-gui, Chicken, Samgyepsal, Doenjang-Jjgae, Dak-galbi, Japchae and Gimbap p<0.01 for Samgye-tang and p<0.05 for Naengmyeon, Kimchi-Jjigae, Dak-galbi, Seolleongtang, Haemul-tang, Hanjeongsik and Tteok-bokki. Jeon and Juk did not show any statistically significant difference. Chinese consumers preferred Korean food for Samgyeopsal, Bulgogi and chicken and less preferred gruel, Hanjeongsik and Kimchi-Jjigae. The highly interested in Korean culture group preferred Samgyeopal, Bulgogi and Chicken, and less preferred Juk, Jeon and Hanjeonsik in that order. This study offers information on the Chinese's preference for different Korean food to any food service enterprises that manage Korean restaurants in China or that sell Korean cuisine and also basic data for differentiated marketing to those entering the Chinese market.

Heat-Wave Data Analysis based on the Zero-Inflated Regression Models (영-과잉 회귀모형을 활용한 폭염자료분석)

  • Kim, Seong Tae;Park, Man Sik
    • Journal of the Korean Data Analysis Society
    • /
    • v.20 no.6
    • /
    • pp.2829-2840
    • /
    • 2018
  • The random variable with an arbitrary value or more is called semi-continuous variable or zero-inflated one in case that its boundary value is more frequently observed than expected. This means the boundary value is likely to be practically observed more than it should be theoretically under certain probability distribution. When the distribution considered is continuous, the variable is defined as semi-continuous and when one of discrete distribution is assumed for the variable, we regard it as zero-inflated. In this study, we introduce the two-part model, which consists of one part for modelling the binary response and the other part for modelling the variable greater than the boundary value. Especially, the zero-inflated regression models are explained by using Poisson distribution and negative binomial distribution. In real data analysis, we employ the zero-inflated regression models to estimate the number of days under extreme heat-wave circumstances during the last 10 years in South Korea. Based on the estimation results, we create prediction maps for the estimated number of days under heat-wave advisory and heat-wave warning by using the universal kriging, which is one of the spatial prediction methods.

Study on Behavior of Slender Bodies in Waves (세장체의 파랑중 거동에 대한 실험에 관한 고찰)

  • Lee, Seung Jae;Kang, Donghoon;Jo, Hyo Jae;Shin, Da Rae
    • Journal of Ocean Engineering and Technology
    • /
    • v.27 no.3
    • /
    • pp.29-35
    • /
    • 2013
  • The exploration areas for maritime resources such as oil and natural gas have gradually moved to deep sea areas. It has become difficult to use existing fixed marine structures, which are very costly to build, because that have reached the uppermost economic limit. Therefore, floating marine structures and flexible marine structures are preferred. In particular, slender bodies such as risers and pipes are important parts of ocean depth marine structures. These slender bodies have more flexible structural characteristics in deep water areas because their overall length becomes longer and thediameter/length slenderness ratio gets smaller. In addition, the dynamic behavior of slender bodies becomes complicated as external forces such as tides and waves act on it directly. In this study, in order to solve these problems, we performed model tests in a 2-D wave basin using flexible slender bodies with different modulus of elasticity values. As a result, we compiled statistics and compared the behaviors of flexible slender bodies with respect to the effect of the modulus of elasticity. We expect that the results could be used as reference data for the design of structures with flexible elements.

A Study on the Clinical Use of 7-zone-diagnostic System(1) Centering around VEGA-DFM 722 and ABR-2000- (7구역진단기의 임상응용에 대한 고찰(1) -VEGA-DFM 722 및 ABR-2000 중심으로-)

  • Song, Beom-Yong
    • Journal of Acupuncture Research
    • /
    • v.23 no.3
    • /
    • pp.231-239
    • /
    • 2006
  • Functional medicine is a system which utilizes certain investigative and treatment methods that are primarily oriented toward the recognition of functional disorder. Functional disorders take place on an energetic plane. This plane is not capturable using our regular investigatory techniques, such as X -ray. ultrasound, computer tomography and laboratory analyses. The 7-zone-diagnostic system(VEGA-DFM 722 and ABR-2000, etc) is a diagnostic device Which applies pulse signals to predetermined bodily locations. Applying alternating positive and negative stress to tissues with positive and negative pulses first manifests itself as negative and positive wave forms. The skin has many functions as an organ. It is the organism's interlace with the outsider world. Hence, the manner in which the skin reacts to external stimuli reflects the current state of the organism(as meridian systems). This system make a diagnosis of functional disorder or some typical organic diseases include stress of the mind or the body, and the energetic situation, reserves. We are known a disorder or disease throw the result chart. This result chart contain disorder flow wave forms and some valuable diagnostic hints (letters ; S, OM, RA, etc). In spite of this 7-zone-diagnostic system that is applied plentifully in the clinical application, there is not a statistics which is suitable. Therefor we must carry out many various research in the future.

  • PDF

A Prediction of Coronary Perfusion Pressure Using the Extracted Parameter From Ventricular Fibrillation ECG Wave (심실세동 심전도 파형 추출 파라미터를 이용한 관상동맥 관류압 예측)

  • Jang Seung-Jin;Hwang Sung-Oh;Yoon Young-Ro;Lee Hyun-Sook
    • The Transactions of the Korean Institute of Electrical Engineers D
    • /
    • v.54 no.4
    • /
    • pp.274-283
    • /
    • 2005
  • Coronary Perfusion Pressure(CPP) is known for the most important parameter related to the Return of Spontaneous Circulation (ROSC), however, clinically measuring CPP is difficult either invasive or non-invaisive method. En this paper, we analyze the correlation between the extracted parameter from VF ECG wave and the CPP with the statistical method, and predict CPP value using the extracted parameters within significance level. the extracted parameters are median frequency(MF), peak frequency(PF), average segment amplitude(ASA), MSA(maximum segment amplitude), Two parameters, MF, and ASA are selected in order to predict CPP value with general regression neural network, and then we evaluated the agreement statistics between the simulated CPP and the measured CPP. In conclusion, the mean and variance of the difference between the simulated CPP and the measured CPP are 8.9716±1.3526 mmHg, and standard deviation 6.4815 mmHg with one hundred-times training and test results. the simulated CPP and the measured CPP are agreed with the overall accuracy $90.68\%$ and kappa coefficient $81.14\%$ as a discriminant parameter of ROSC.