• 제목/요약/키워드: Wave statistics

검색결과 154건 처리시간 0.024초

Homogeneity Analysis for the SMR Brainwave by the Functional Lateralization of the Brain Based on the Science Learning Methods

  • Kwon, Hyung-Kyu;Cho, Jang-Sik
    • Journal of the Korean Data and Information Science Society
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    • 제18권3호
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    • pp.721-733
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    • 2007
  • The purpose of this research was to determine the effects of the functional lateralization of the brain variables related to the sex, the scientific attitude and the scientific exploration skills. The science instruction is divided in each type of the lecturing class with the experiment class. As for the degree of SMR brainwave activation in each stage are presented while accumulating the brain waves from the right, left and the whole brain waves are analyzed during the science learning activities. It is therefore reasonable to consider the science instruction types and brain lateralization to enhance the science learning effectiveness. Sensorimotor rhythm brainwave as the low Beta is represented well to show the thought process. Category quantification scores and objective scores are calculated to show the visual positioning map for the relationships of the categories by homogeneity analysis.

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파랑에 관한 레이더 이미지 시뮬레이션을 위한 레이더 수신 출력 도입 기법 연구 (A Study on Radar Image Simulation for Ocean Waves Using Radar Received Power)

  • 박준수;양영준;박승근;권순홍
    • 한국해양공학회지
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    • 제24권1호
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    • pp.47-52
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    • 2010
  • This study presents a modified scheme for the radar image simulation of sea waves. A simulated radar image was obtained by taking into account the dot product of the directed vector from the radar and the normal vector of the sea surface. Moreover, to calculate the radar image, we used the radar received power and radar cross section. To demonstrate the effectiveness of the proposed scheme, the wave spectrum from field data was utilized to obtain the simulated sea waves. The radar image was simulated using numerically generated sea waves. The wave statistics from the simulation agrees comparatively with those of the original field data acquired by real radar measurements.

Multivariable Bayesian curve-fitting under functional measurement error model

  • Hwang, Jinseub;Kim, Dal Ho
    • Journal of the Korean Data and Information Science Society
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    • 제27권6호
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    • pp.1645-1651
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    • 2016
  • A lot of data, particularly in the medical field, contain variables that have a measurement error such as blood pressure and body mass index. On the other hand, recently smoothing methods are often used to solve a complex scientific problem. In this paper, we study a Bayesian curve-fitting under functional measurement error model. Especially, we extend our previous model by incorporating covariates free of measurement error. In this paper, we consider penalized splines for non-linear pattern. We employ a hierarchical Bayesian framework based on Markov Chain Monte Carlo methodology for fitting the model and estimating parameters. For application we use the data from the fifth wave (2012) of the Korea National Health and Nutrition Examination Survey data, a national population-based data. To examine the convergence of MCMC sampling, potential scale reduction factors are used and we also confirm a model selection criteria to check the performance.

Empirical variogram for achieving the best valid variogram

  • Mahdi, Esam;Abuzaid, Ali H.;Atta, Abdu M.A.
    • Communications for Statistical Applications and Methods
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    • 제27권5호
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    • pp.547-568
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    • 2020
  • Modeling the statistical autocorrelations in spatial data is often achieved through the estimation of the variograms, where the selection of the appropriate valid variogram model, especially for small samples, is crucial for achieving precise spatial prediction results from kriging interpolations. To estimate such a variogram, we traditionally start by computing the empirical variogram (traditional Matheron or robust Cressie-Hawkins or kernel-based nonparametric approaches). In this article, we conduct numerical studies comparing the performance of these empirical variograms. In most situations, the nonparametric empirical variable nearest-neighbor (VNN) showed better performance than its competitors (Matheron, Cressie-Hawkins, and Nadaraya-Watson). The analysis of the spatial groundwater dataset used in this article suggests that the wave variogram model, with hole effect structure, fitted to the empirical VNN variogram is the most appropriate choice. This selected variogram is used with the ordinary kriging model to produce the predicted pollution map of the nitrate concentrations in groundwater dataset.

Loads and motions for a spar-supported floating offshore wind turbine

  • Sultania, Abhinav;Manuel, Lance
    • Wind and Structures
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    • 제22권5호
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    • pp.525-541
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    • 2016
  • An offshore wind turbine supported by a spar buoy floating platform is the subject of this study on tower and rotor extreme loads. The platform, with a 120-meter draft and assumed to be sited in 320 meters of water, supports a 5 MW wind turbine. A baseline model for this turbine developed at the National Renewable Energy Laboratory (NREL) is employed in stochastic response simulations. The support platform, along with the mooring system consisting of three catenary lines, chosen for loads modeling, is based on the "Hywind" floating wind turbine concept. Our interest lies in gaining an understanding of the dynamic coupling between the support platform motion and the turbine loads. We first investigate short-term response statistics using stochastic simulation for a range of different environmental wind and wave conditions. From this study, we identify a few "controlling" environmental conditions for which long-term turbine load statistics and probability distributions are established.

교란 대기를 통한 스펙클 전파의 통계적 코바리언스 함수의 효과 (Effect of the covariance function on the statistics of speckle propagation through the turbulent atmosphere.)

  • 성평식;박계원
    • 한국정보통신학회논문지
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    • 제3권1호
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    • pp.29-34
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    • 1999
  • 본 논문은 확장된 Huygens-Fresnel원리를 이용하여 섭동대기 공간을 통하여 진행하는 스팩클 전파에서 수신된 강도를 통계적으로 해석하였다. 그 결과 이러한 수식들은 파구조 함수뿐만 아니라 log-amplitude 코바리안스를 포함하고, 정규화 바리언스가 섭동세기에 의존하여 1 이상이 되는 것을 알았다.

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유방암 절제술 여성의 맥파요인 연구 (A Study on the Pulse Wave Parameter in Post Mastectomy Women)

  • 김경철;박상욱;김이순;김윤희
    • Korean Journal of Acupuncture
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    • 제28권4호
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    • pp.101-112
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    • 2011
  • Objectives : This study was done to investigate the degree of the pulse wave parameter of post-mastectomy women and to identify the relationships between each of them. Methods : Data were obtained from public health center in Busan Metropolitan city. Participants were 82 post-mastectomy women aged 31-82. the data collection was from Oct, 1, 2010 to Oct, 31, 2010. the data were analyzed with descriptive statistics, one-way ANOVA, Duncan test. A p-value less than .05 was considered significant by 2-tailed test. All statistical analyses were performed with SPSS/Win(ver 12.0). Results : As for the difference in the pulse wave by the general characteristics. The pulse energy was showed highly in the order of Chon, Quan and Chuk of left and right pulse respectively. In the pulse energy of left Quan and right Chon, the case of both mastectomy was showed highly and in the pulse energy of left Chuk, the case of right mastectomy was showed highly. Left and right pulse energy of menopause female were significantly higher than normal range except left Chon and Chuk. In h1, h2, h4, h5, t1, t2, AP and Aw, the pulse energy of left Chon was showed the largest significantly. In As, the pulse energy of right Chon was showed the smallest and in Ad, right Chuk was showed the largest. In RAI, right and left Chuk was showed the highest respectively. Conclusions : From these result, we can see that there are relation between women's age, area of operation breast and menopause after mastectomy in pulse wave. The result of this study will become basic data necessary for the Oriental Medicine treatment to reduce or prevent women's functional difficulties, symptomatology after mastectomy.

소형 선박의 충돌 회피 시스템 검증에 관한 연구 (A Study on the Validation of the Collision Avoidance System for Small-size Vessels)

  • 편장훈;류성곤;김인섭
    • 해양환경안전학회지
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    • 제27권7호
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    • pp.1023-1030
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    • 2021
  • 중앙해양안전심판원(2019)에서 발표한 최근 5년의 해양사고통계자료에 따르면 충돌사고의 대부분은 20톤 미만의 어선에서 발생하고 있으며 전방 부주의, 경계 소홀 등의 운항과실로 인한 사고가 주요 원인으로 나타나고 있다. 이러한 사고 방지를 위해 운항자를 대상으로 훈련 및 교육을 강화하고 있지만 충돌사고는 빈번히 발생되고 있으며 충돌 사고를 줄이기 위한 기술적인 방안 또한 지속적으로 개발중에 있다. 본 연구에서는 고속 활주형 소형 선박에 WAVE 통신 기술을 적용하여 선박 간 거리, 속도, 방위에 기반한 조우 상황을 고려하여 충돌 회피 동작이 가능한 제어 알고리즘을 개발하였으며, WAVE 통신-제어기를 결합하여 충돌 회피 시스템을 구축하였다. 그리고 충돌 회피 동작의 검증을 위해 두 소형 선박간의 정면, 추월, 교차의 3가지의 조우 시나리오에 대해서 시뮬레이션을 수행하고 실선 시험을 통해서 충돌 회피 알고리즘을 검증하였다.

공간 극단값의 분계점 모형 사례 연구 - 한국 여름철 강수량 (Threshold Modelling of Spatial Extremes - Summer Rainfall of Korea)

  • 황승용;최혜미
    • 응용통계연구
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    • 제27권4호
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    • pp.655-665
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    • 2014
  • 폭염, 폭우와 가뭄 등과 같은 이상 기후 현상에 대한 적절한 대응이 최근 많이 요구되고 있다. 이상 기후 현상을 분석하기 위해 극단값 분석 기법을 적용할 수 있는데, 본 논문은에서는 한국의 여름철 강수량 자료(1973년부터 2012년까지의 5월부터 9월)를 분계점 초과값 모형으로 분석해보았다. 분계점은 한국의 기상관측소들을 5개의 군집으로 나누어, 각 군집별로 지리 정보와 시간을 공변량으로 하는 분위수 회귀 방법을 통하여 추정하였다. Northrop과 Jonathan (2011)과 같이 극단값들이 시공간적으로 독립이라고 가정하고 분석한 후, 추정오차와 검정 과정에 공간 종속성을 반영하였다.

Determining a BMDL of Blood Lead Based on ADHD Scores Using a Semi-Parametric Regression

  • Kim, Ah-Hyoun;Ha, Min-A;Kim, Byung-Soo
    • 응용통계연구
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    • 제25권3호
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    • pp.389-401
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    • 2012
  • This paper derives a benchmark dose(BMD) and its 95% lower confidence limit(BMDL) using a semi-parametric regression model for small lead based changes in attention-deficit hyperactivity disorder(ADHD) scores in the first wave of the Children's Health and Environment Research(CHEER) survey data, which have been regularly collected in South Korea since 2005. Ha et al. (2009) showed that the appearance of ADHD symptoms had a borderline trend of increasing with the blood lead concentration. Butdz-J${\o}$rgensen (EFSA, 2010a) derived the BMDL of lead corresponding to a benchmark region of 1 full intelligent quotient (IQ) score using the raw data in Lanphear et al. (2005, EHP). European Food Safety Authority (EFSA, 2010b) determined the BMDL of $1.2{\mu}g/dl$ as a reference point for the characterization of lead when assessing the risk of the intellectual deficit measured by IQ scores. Kim et al. (2011) indicated that an even lower BMDL could be obtained based on the ADHD score; however, the BMDLs depended heavily upon the model assumptions. We show in this paper that a semi-parametric approach resolves the model dependence of BMDLs.