• Title/Summary/Keyword: Frequency distributions

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Frequency Analysis of Extreme Rainfall by L-Moments (L-모멘트법에 의한 극치강우의 빈도분석)

  • Maeng, Sung-Jin;Lee, Soon-Hyuk;Kim, Byung-Jun
    • Proceedings of the Korean Society of Agricultural Engineers Conference
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    • 2002.10a
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    • pp.225-228
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    • 2002
  • This research seeks to derive the design rainfalls through the L-moment with the test of homogeneity, independence and outlier of data on annual maximum daily rainfall in 38 Korean rainfall stations. To select the fit appropriate distribution of annual maximum daily rainfall data according to rainfall stations, applied were Generalized Extreme Value (GEV), Generalized Logistic (GLO) and Generalized Pareto (GPA) probability distributions were applied. and their aptness was judged Dusing an L-moment ratio diagram and the Kolmogorov-Smirnov (K-S) test, the aptitude was judged of applied distributions such as GEV, GLO and GPA. The GEV and GLO distributions were selected as the appropriate distributions. Their parameters were estimated Targetingfrom the observed and simulated annual maximum daily rainfalls and using Monte Carlo techniques, the parameters of GEV and GLO selected as suitable distributions were estimated and. dDesign rainfallss were then derived, using the L-moment. Appropriate design rainfalls were suggested by doing a comparative analysis of design rainfall from the GEV and GLO distributions according to rainfall stations.

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Differentiation and Distrbution of the Choline Acetyltransferase-immunoreactive Nerve Cells in the Magnocellular Preoptic Nucleus of the Rat Forebrains during the Postnatal Development

  • Chung, Young-Wha;Choi, Yoon-Jin
    • Animal cells and systems
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    • v.1 no.3
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    • pp.483-489
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    • 1997
  • This study was performed to investigate the differentiation and distribution of choline acetyltransferase (ChAT}-immunoreactive cells in the magnacellular preoptic nucleus (MCPO) of the postnatal and adult rat forebrains, utilizing techniques of immunocytochemistry. According to the cell shape and the ratio of long axis versus short axis of cell soma, the ChATimmunoreactive nerve cells in the MCPO were classified into six types: 1) round, 2) oval, 3) elongated, 4) fusiform, 5) triangular, and 6) polygonal types. Frequency distributions of the oval and round nerve cells on the postnatal day (PND) 0 were observed to be high. But in the adult, frequency distributions of the same cells were shown to decrease. Compared to those of the postnatal rats, frequency distributions of elongated, fusiform, triangular, and polygonal nerve cells in the adult were increased. The total mean volumes of ChAT-immunoreactive cell somata in the MCPO of PND 0 rat were the lowest, while those in the PND 17 rat were shown to be the highest and decreased in the adult. The soma volumes of the immunoreactive cells at the PND 17 were evenly distributed, but those in the other developmental stages (e.g. PND 7 and adult) appeared to exhibit unimodal distributions. On the electron micrography, the free ribosomes, polysomes, and rough endoplasmic reticula (RER) of the nerve cells in the MCPO of PND 21 rat forebrains were immunoreactive to ChAT in the tissues untreated with triton X-100. According to the observations in the present study, it is considered that the ChAT-immunoreactive nerve cells in the MCPO of the rat forebrains are differentiated throughout the following processes during the postnatal development: 1) increase in cell soma volumes, 2) development of neurites, 3) increase in the frequency of differentiated cell types, and 4) decrease in cell soma volumes. The ribosomes, polysomes, and RER are considered to be closely related to the intracellular localization and biosynthesis of the ChAT but not Golgi complex.

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A bivariate extension of the Hosking and Wallis goodness-of-fit measure for regional distributions

  • Kjeldsen, Thomas Rodding;Prosdocimi, Ilaria
    • Proceedings of the Korea Water Resources Association Conference
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    • 2015.05a
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    • pp.239-239
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    • 2015
  • This study presents a bivariate extension of the goodness-of-fit measure for regional frequency distributions developed by Hosking and Wallis [1993] for use with the method of L-moments. Utilising the approximate joint normal distribution of the regional L-skewness and L-kurtosis, a graphical representation of the confidence region on the L-moment diagram can be constructed as an ellipsoid. Candidate distributions can then be accepted where the corresponding the oretical relationship between the L-skewness and L-kurtosis intersects the confidence region, and the chosen distribution would be the one that minimises the Mahalanobis distance measure. Based on a set of Monte Carlo simulations it is demonstrated that the new bivariate measure generally selects the true population distribution more frequently than the original method. An R-code implementation of the method is available for download free-of-charge from the GitHub code depository and will be demonstrated on a case study of annual maximum series of peak flow data from a homogeneous region in Italy.

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Distributions on F0 and Amplitude of Persons with Cerebral Palsy in the Reading Task (읽기과제에서 나타난 뇌성마비인의 기본주파수 및 진폭의 분포 특성)

  • Nam, Hyun-Wook;Choi, Yang-Gyu
    • MALSORI
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    • no.66
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    • pp.1-20
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    • 2008
  • The purpose of this study was to investigate the characteristics of fundamental frequency(F0) and amplitude distributions in persons with cerebral palsy(CP) in the reading task. Participants were divided into three groups: 6 persons with spastic CP, 6 persons with athetoid CP and 6 normal persons who are around 15-20 years old. On the results of this study, firstly, in F0 distributions, most of the spastic CPs tended to appear narrow distributions on the basis of mode, but most of the athetoid CPs were opposite, and both of the CP groups tended to distribute highly on lower and higher frequencies than mean and mode. On the other hand, normal persons had a tendency to appear narrow distributions on the basis of mode. Finally, in amplitude distributions, the spastic CPs showed a tendency that there are little differences between the distribution of mode and the others, and most of the athetoid CPs showed a tendency that the distributions of mode were higher than the others. In addition to, the normal persons had a tendency that the distributions of mode were remarkably higher than both of the CP groups.

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Study on Low Frequency Swishing Sound Field by a Singularity in Circular Motion with Large Radius (큰 반경의 원운동을 하는 점 음원에 의한 저주파수 스위싱 음장 분석)

  • Lee, Gwang-Se;Cheong, Cheolung
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.24 no.7
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    • pp.569-574
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    • 2014
  • In order to investigate low frequency swishing noise of wind turbines, acoustic source model using a singularity in circular motion is introduced to derive analytic solution of Lowson acoustic analogy in time domain. Results in time and frequency domains computed by the solution show apparent modulation of amplitude and frequency. The solution indicates that time histories of acoustic pressure at receiver points varied significantly according to receiver's directional location, even when the retarded time distributions are similar. However, the corresponding time-averaged spectra of sound pressure at the receiver locations where the retarded time distributions are almost same are not significantly different. It can be inferred from these results that the time-averaged sound pressure spectra which cannot take into account the detailed difference in the time-variation of wind turbine noise may not represent the sound quality of wind turbines due to its swishing. Finally, as an introduction of procedure to quantify low frequency swishing noise level, relative variation of overall sound pressure level is obtained using tonal low frequency noise model.

Analysis of Correlation on Physical Characteristics and Bed Materials in Natural Rivers (자연하천에서 하도의 물리적 특성과 하상재료의 상관관계분석)

  • Kim, Ki-Heung
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.13 no.2
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    • pp.95-104
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    • 2010
  • The purpose of this study is to analyze the correlation between physical stream characteristics and bed materials in natural rivers. Accordingly, four natural rivers were selected reference streams, they were Nam river, Sumjin River, Naesung River and Han River. Grain size distributions of bed materials were gravels, cobbles and boulders in Han river and Nam river, were sand, gravels, cobbles and boulders in Sumjin river and were sand in Naesung river. Four reference streams were divided into each two reference reaches (straight and bend) by plan and profile characteristics of naturally meandering stream. Therefore various reference reaches were chosen in the aspect of physical stream characteristics and grain size distributions. The results investigated and analyzed are as follows. The streams that grain sizes distributions of river bed materials were coarse were stable because they had variety of bed slope without sediment deposition, and then the riffles frequency and the physical characteristics were various. Also, velocitydepth regime were various in four kinds, and the response parts for water level change were small, so that channel flow status were stable and excellent condition. On the other hand, sand river that grain sizes distributions of river bed materials were fine had not the variety of parameters as velocity-depth regimes, sediment deposition, channel flow status and riffles frequency, so that the physical stream characteristics were not various.

A Study on the Frequency Structure of Probability Distributions Using Social Network Analysis (사회연결망분석을 이용한 확률분포들의 이용빈도 구조에 대한 연구)

  • Jang, Dae-Heung;Yi, Seong-Baek
    • The Korean Journal of Applied Statistics
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    • v.24 no.6
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    • pp.1169-1179
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    • 2011
  • Through social network analysis using portal site information, we study the relation of the probability distributions that appear in statistics textbooks with probability distributions that appear in daily life. Based on daily life, we discuss probability distributions that must be emphasized in frequent use.

A Clinical Study of 580 Cases on Hypersensitive Rhinitis including Allergic Rhinitis (알레르기 비염을 포함하는 과민성 비염 환자 580례에 대한 임상적 고찰sdf)

  • Shin, Sang-Ho;Kim, Ja-Hye;Kim, Mi-Bo;Ko, Woo-Shin;Yoon, Hwa-Jung
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.20 no.1 s.32
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    • pp.218-227
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    • 2007
  • Objective : The purpose of this study is to investigate outpatients of hypersensitive rhinitis including allergic rhinitis who had visited to Hospital of Oriental Medicine. Method : We analyzed statistics study in 580 patients, who had visited to the Dept. of dermatology, ophthalmology & otorhinolayngology Hospital of Oriental Medicine Dongeui University from March, 1998 to December, 2006. Results : The results were as follows. 1. There is more male(53.28%) than femal(46.72%). The age distributions of patients showed highest in 20-29 years, followed by 10-19 years, 30-39 years in order. 2. The yearly distributions of patients showed highest in 2004, followed by 2001, 2005 in order. The seasonal distributions of patients showed highest in fall, followed by winter, summer, spring in order. The monthly distributions of patients showed highest in September, followed by August, October in order. 3. The distributions of number of times in treatment showed highest in 1-5 times. The distributions of duration of treatment showed highest in 1 week. In the treatment method, a major portion of treatment methods was acupuncture, followed by herbal medicine treatment, aroma therapy in order. 4. The Frequency of use of Prescriptions showed highest in Bojungikgi-Tanggami. The Frequency of use of Extract showed highest in Sochungryong-Tang. 5. The distribution of past history showed highest in Atopic dermatitis. The distribution of Rhinologic Complication showed highest in Paranasal sinusitis.

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AE characteristic of PE pipe under tensile test (PE 배관의 인장시험 동안 발생한 AE 특성)

  • Jeong, Jeong-Hwan;Nam, Ki-Woo;Ahn, Seok-Hwan;Park, In-Duck
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2002.05a
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    • pp.130-133
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    • 2002
  • Polyethylene pressure pipe has been used with a gas pipe material because of workability and stability etc.. Researches on characteristics of polyethylene pressure pipe are carried out, but there are rare. In this study, the tensile test was performed on polyethylene pipe. From the tensile test, AE signals were detected and estimated in real time. Also, the time-frequency analysis of AE signals was analyzed. From test results, PE pipes were displayed typical stress-strain curves oj semi-crystalline polymer. As result analyzed AE signals, could divide stress-strain curves could be divided into four stages. In the elastic region, signals were not detected. Low amplitude distributions of 30-35dB appeared after yielding, and high amplitude distributions of 30-60dB appeared with increased extension. From the time-frequency analysis of AE signals, the frequency band of 100kHz appeared mainly. Also, the frequency band of 300kHz appeared before the necking phenomenon spreads into the whole region, and the frequency band of 500kHz appeared on extension earlier.

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Stability/instability of the graphene reinforced nano-sized shell employing modified couple stress model

  • Yao, Zhigang;Xie, Hui;Wang, Yulei
    • Wind and Structures
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    • v.32 no.1
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    • pp.31-46
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    • 2021
  • The current research deals with, stability/instability and cylindrical composite nano-scaled shell's resonance frequency filled by graphene nanoplatelets (GPLs) under various thermal conditions (linear and nonlinear thermal loadings). The piece-wise GPL-reinforced composites' material properties change through the orientation of cylindrical nano-sized shell's thickness as the temperature changes. Moreover, in order to model all layers' efficient material properties, nanomechanical model of Halpin-Tsai has been applied. A functionally modified couple stress model (FMCS) has been employed to simulate GPLRC nano-sized shell's size dependency. It is firstly investigated that reaching the relative frequency's percentage to 30% would lead to thermal buckling. The current study's originality is in considering the multifarious influences of GPLRC and thermal loading along with FMCS on GPLRC nano-scaled shell's resonance frequencies, relative frequency, dynamic deflection, and thermal buckling. Furthermore, Hamilton's principle is applied to achieve boundary conditions (BCs) and governing motion equations, while the mentioned equations are solved using an analytical approach. The outcomes reveal that a range of distributions in temperature and other mechanical and configurational characteristics have an essential contribution in GPLRC cylindrical nano-scaled shell's relative frequency change, resonance frequency, stability/instability, and dynamic deflection. The current study's outcomes are practical assumptions for materials science designing, nano-mechanical, and micromechanical systems such as micro-sized sensors and actuators.