• Title/Summary/Keyword: Kurtosis and skewness

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A Grain Size Analysis of Bottom Sediments of Yeongil Bay, Korea (한국 영일만 해저퇴적물의 입도분포)

  • Park, Byong-Kwon;Song Moo-Young
    • 한국해양학회지
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    • v.7 no.2
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    • pp.74-85
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    • 1972
  • This paper studied the grain size distribution of bottom sediments of Yeongil Bay which is located at the southeastern part of the Korean Peninsula. Sixty four samples collected with snapper and dredger are analyzed by roe Tap Sieve Shaker and Pipette Method. The moment parameters are calculated with the method of Friedman(1961). Most samples are composed of sand size sediments and a few samples are composed of silt and clay. The Yeongil Bay can be divided into gravel-granule zone, sand zone, and silt-clay zone. The sediments near Yeonam- Dong and Hyongsan river are moderately sorted and others are very poorly sorted according to scheme of Friedman91962). In general, sorting values are ranged from 1.0 to 3.5. The samples near Janggigap and Masin-Dong show negative and others show positive skewness values. Skewness values are ranged from -1 to 2. All samples show the leptokurtic distribution except for the samples near Masin- dong and at the deepest place near Janggigap. Kurtosis values are ranged from -1.5 to 21.9. The samples of gravel-granule zone contain more than 50% and those of silt-clay zone contain less than 50% of CaCO$\_$3/. Four different colors, black, yellow, brown and gray, are shown in the sediments of Yeongil Bay.

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Acoustic analysis of Korean affricates produced by dysarthric speakers with cerebral palsy (뇌성마비 마비말장애 성인의 파찰음 실현 양상 분석)

  • Mun, Jihyun;Kim, Sunhee;Chung, Minhwa
    • Phonetics and Speech Sciences
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    • v.13 no.2
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    • pp.45-55
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    • 2021
  • This study aims to analyze the acoustic characteristics of Korean affricates produced by dysarthric speakers with cerebral palsy. Korean fricatives and affricates are the consonants that are prone to errors in dysarthric speech, but previous studies have focused only on fricatives. For this study, three affricates /tɕ, tɕh, ͈tɕ/ appearing at word initial and intervocalic positions produced by six mild-moderate male speakers of spastic dysarthria are selected from a QOLT database constructed in 2014. The parameters representing the acoustic characteristics of Korean affricates were extracted by using Praat: frication duration, closure duration, center of gravity, variance, skewness, kurtosis, and central moment. The results are as follows: 1) frication duration of the intervocalic affricates produced by dysarthric speakers was significantly longer than that of the non-disordered speakers; 2) the closure duration of dysarthric speakers was significantly longer; 3) in the case of the center of gravity, there was no significant difference between the two groups; 4) the skewness of the dysarthric speakers was significantly larger; and 5) the central moment of dysarthric speakers was significantly larger. This study investigated the characteristics of the affricates produced by dysarthric speakers and differences with non-disordered speakers.

The combination of a histogram-based clustering algorithm and support vector machine for the diagnosis of osteoporosis

  • Kavitha, Muthu Subash;Asano, Akira;Taguchi, Akira;Heo, Min-Suk
    • Imaging Science in Dentistry
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    • v.43 no.3
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    • pp.153-161
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    • 2013
  • Purpose: To prevent low bone mineral density (BMD), that is, osteoporosis, in postmenopausal women, it is essential to diagnose osteoporosis more precisely. This study presented an automatic approach utilizing a histogram-based automatic clustering (HAC) algorithm with a support vector machine (SVM) to analyse dental panoramic radiographs (DPRs) and thus improve diagnostic accuracy by identifying postmenopausal women with low BMD or osteoporosis. Materials and Methods: We integrated our newly-proposed histogram-based automatic clustering (HAC) algorithm with our previously-designed computer-aided diagnosis system. The extracted moment-based features (mean, variance, skewness, and kurtosis) of the mandibular cortical width for the radial basis function (RBF) SVM classifier were employed. We also compared the diagnostic efficacy of the SVM model with the back propagation (BP) neural network model. In this study, DPRs and BMD measurements of 100 postmenopausal women patients (aged >50 years), with no previous record of osteoporosis, were randomly selected for inclusion. Results: The accuracy, sensitivity, and specificity of the BMD measurements using our HAC-SVM model to identify women with low BMD were 93.0% (88.0%-98.0%), 95.8% (91.9%-99.7%) and 86.6% (79.9%-93.3%), respectively, at the lumbar spine; and 89.0% (82.9%-95.1%), 96.0% (92.2%-99.8%) and 84.0% (76.8%-91.2%), respectively, at the femoral neck. Conclusion: Our experimental results predict that the proposed HAC-SVM model combination applied on DPRs could be useful to assist dentists in early diagnosis and help to reduce the morbidity and mortality associated with low BMD and osteoporosis.

Field measurements of wind pressure on an open roof during Typhoons HaiKui and SuLi

  • Feng, Ruoqiang;Liu, Fengcheng;Cai, Qi;Yan, Guirong;Leng, Jiabing
    • Wind and Structures
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    • v.26 no.1
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    • pp.11-24
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    • 2018
  • Full-scale measurements of wind action on the open roof structure of the WuXi grand theater, which is composed of eight large-span free-form leaf-shaped space trusses with the largest span of 76.79 m, were conducted during the passage of Typhoons HaiKui and SuLi. The wind pressure field data were continuously and simultaneously monitored using a wind pressure monitoring system installed on the roof structure during the typhoons. A detailed analysis of the field data was performed to investigate the characteristics of the fluctuating wind pressure on the open roof, such as the wind pressure spectrum, spatial correlation coefficients, peak wind pressures and non-Gaussian wind pressure characteristics, under typhoon conditions. Three classical methods were used to calculate the peak factors of the wind pressure on the open roof, and the suggested design method and peak factors were given. The non-Gaussianity of the wind pressure was discussed in terms of the third and fourth statistical moments of the measured wind pressure, and the corresponding indication of the non-Gaussianity on the open roof was proposed. The result shows that there were large pulses in the time-histories of the measured wind pressure on Roof A2 in the field. The spatial correlation of the wind pressures on roof A2 between the upper surface and lower surface is very weak. When the skewness is larger than 0.3 and the kurtosis is larger than 3.7, the wind pressure time series on roof A2 can be taken as a non-Gaussian distribution, and the other series can be taken as a Gaussian distribution.

Partial Discharge Characteristics of Metallic Particles Under HVDC in SF6 Gas (SF6 가스 중 HVDC에서 금속 파티클의 부분방전 특성)

  • Kim, Sun-Jae;Jo, Hyang-Eun;Wang, Guoming;Yun, Min-Young;Kil, Gyung-Suk
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.28 no.12
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    • pp.831-836
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    • 2015
  • This paper dealt with the PD (partial discharge) characteristics produced by metallic particles presented in a gas insulated switchgear. Four types of metallic particles such as a ball, a trapezoid, a rectangle, and a twist were fabricated and placed in a PD cell filled with $SF_6$ gas. PD pulses were detected through a $50{\Omega}$ non-inductive resistor. Calibration was carried out according to IEC 60270 and the sensitivity was calculated as 4 mV/pC. Apparent charge, pulse count, DIV (discharge inception voltage), DEV (discharge extinction voltage), and TRPD (time resolved partial discharge) were analyzed. Among the metallic particle types, the twist frequently occurred PD pulse at the lowest DIV, while the rectangle showed the highest. DEV of the twist was about 2 times lower than that for the rectangle. Kurtosis of ball clustered at high value, and skewness of other three metallic particles distributed at low value. TRPD showed different distribution by metallic particle types.

Identification of Defect Type by Analysis of a Single PD Pulse in Gas Insulated Structure (가스절연 구조에서 단일 부분방전펄스 분석에 의한 결함 판별)

  • Jo, Hyang-Eun;Kim, Sun-Jae;Jeong, Gi-Woo;Kil, Gyung-Suk
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.28 no.5
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    • pp.320-325
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    • 2015
  • This paper dealt with a defect identification algorithm which is based on single partial discharge (PD) pulse analysis in gas insulated structure. Four types of electrode systems such as a needle-plane, a plane-needle, a free particle and a crack inside spacer were fabricated to simulate defects in gas insulated switchgear (GIS). We measured single PD pulse by an oscilloscope with a sampling rate of 5 GS/s and a frequency bandwidth of 1 GHz. Data aquisition and signal processing were controlled by a LabVIEW program. Physical shapes of PD pulses were compared with kurtosis, skewness and time-based parameters as rising time, falling time and pulse-width. These parameters were analysed by an algorithm with a back propagation algorithm (BPA). By applying the algorithm, the identification rate was 97% for the needle-plane electrode, 96% for the plane-needle electrode, 91% for the free particle and 93% for the crack inside spacer. The results verified that the algorithm could identify the type of defects in GIS.

Development and Validation of Inventory of Peer Relation Problems for Elementary School Children (아동용 교우관계문제검사의 개발과 타당화)

  • Jeong, Hye-Won
    • The Korean Journal of Elementary Counseling
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    • v.7 no.1
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    • pp.37-66
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    • 2008
  • This study has been carried out with the aims of developing a comprehensive inventory of peer relation problems, which is based on the Korean Inventory of Interpersonal Problems Circumplex scales (KIIP-C). It also aims to examine reliability and validity of the inventory, and provide a preliminary norms. For the current study, inventory items were culled from the following sources: the Korean Inventory of Interpersonal Problems Circumplex scales (KIIP-C), various current scales dealing with peer relations of children, and a survey of children's peer relation problems. The preliminary items for each scale were administered to 220 fourth through sixth graders. The resulting skewness of distribution, kurtosis, mean and standard deviation, item-total correlation, internal consistency, and meanings of the items were comprehensively considered in selecting the final 64 items. In order to check on reliability, internal consistency, convergence and discrimination reliability of the final items and scales, the data were collected from 1,046 fourth through sixth graders currently attending four elementary schools. The study results can be summarized as follows. Internal consistency of the inventory of peer relation problems showed the range between .70-.94 (median value of .75), split-half reliability between .67-.83 (median value of .75), and test-retest reliability between .69-.88 (median value of .81). Inter-correlation of 8 scale scores and factor analysis results of individual ipsative scores showed that the circumplex property of inventory of peer relation problems is appropriate. Regarding correlations between various existing indices and scales related to peer relation problems, both convergence reliability and discrimination reliability were found to be fair. When the scale scores for the inventory of peer relation problems compared according to the factors of gender and grade, the primary effects of gender and grade were statistically meaningful whereas effects of interaction between gender and grade were not. This study can be considered meaningful in that it constructed an inventory for a comprehensive evaluation of peer relation problems specific for children and provided preliminary norms.

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A Study on Nutritional Status of the Korean Farmers and Analysis of Relationship between Related Variables (한국농민의 영양상태와 관련변인간의 관계분석)

  • 이동태
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.19 no.3
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    • pp.248-262
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    • 1990
  • General purpose of the study was to understend nutritional status of the Korean farmers and thus provide rural nutrition intervention programs with more useful in formation and data. The data for the study was collected two times from the 603 sample farm households in 1982 and 1987. The main results of the study were as follows ; 1) Food intake of the Korean farmers was highly dependent upon vegetable foods especially on cereals and gains. However the unbalanced food intake pattern was gradually improved as consumption of vegetable foods was decreased from 992.8 grams per person per day in 1982 to 946.4g in 1987 and that of animal foods increased from 54.2g to 91.4g . 2) In mean value analysis on nutrient intake of the farmeres intakes of energy and protein were nearly reached to Recommended Dietary Allowances(RDA) level; intakes of calcium vitamin A and riboflavin were quite deficient whereas iron thiamin niacin and ascorbic acid were well over. From 1982 to 1987 intakes of all nutrients except energy were increased. 3) In distribution analysis on nutrient intake coefficient of variation(CV) of all nutrients except iron was increased. skewness(SK) the coefficients of calcium iron vitamin A riboflavin and ascorbic acid were decreased Kurtosis (Ku) of iron and vitamin A was increased. On the whole distributions of nutrient intake of the farmers were changed in undesirable ways although the mean values of the nutrient intake were improved 4) In relationship analysis among 115 relationships 76 relationships were consistent between 1982 and 1987. Of 76 consistent relationships only 10 relationship were significant at 5% level such as the protein intake level and the balance of food intake calcium intake level and the age etc.

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Correlation between Uncertainty and Quality of Life of the Elderly People (노인의 불확실성과 삶의 질과의 관계)

  • Kim, Hyun-Seung;Cho, Sung-Hyoun
    • Journal of The Korean Society of Integrative Medicine
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    • v.10 no.4
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    • pp.153-163
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    • 2022
  • Purpose : The purpose of this study was to investigate the differences between uncertainty of chronic diseases and quality of life with regard to elderly people. Methods : The participants of this study were 350 elderly people, aged over 65 years. The collected data were analyzed using the SPSS Window program and the general characteristics of the participants and sub-domains of quality of life were analyzed by several frequency analyses and descriptive statistics such as mean, standard deviation, skewness, and kurtosis. Further, the differences between the sub-domains of uncertainty and sub-domains of quality of life were analyzed through independent t-test and one-way ANOVA. In order to reach conclusive results, post-test was analyzed by the Scheffe test. In addition, Pearson's correlation analysis was performed to determine the correlation between the target categories. A significance level of 𝛼=.05 was used to verify statistical significance. Results : As a result of examining "uncertainty" with respect to general characteristics, such as older age, low educational background, and chronic diseases, it was observed that the more intense these factors became, the more the level of uncertainty increased. In addition, it was also noted that except "accompanying diseases" in social domain, the participants enjoyed a high level of quality of life. The correlation was noted between domains of complexity and sociality (p<.01), domains of inconsistency and sociality (p<.01), domains of complexity and living environment (p<.01), domains of inconsistency and living environment (p<.01), and total score of uncertainty and total quality of life (p<.01). Conclusion : In this study, differences were found between "uncertainty" and "quality of life" of elderly people; the correlation between the sub-domains based on general traits was found to be negative (-). This suggests that objective evidence can be presented for the prevention of diseases by using mental health programs for the elderly in future.

Population Pharmacokinetics for Gentamicin in Korean and Caucasian Appendicitis Patients Using Nonparametric Expected Maximum (NPEM) Algorithm (한국인과 코카시안 충수돌기염 환자에서 비모수적 기대최대치(NPEM) 연산방법에 의한 겐타마이신의 모집단 약물동태학)

  • Burm, Jin-Pil
    • Korean Journal of Clinical Pharmacy
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    • v.21 no.2
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    • pp.74-80
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    • 2011
  • Population pharmacokinetics for gentamicin were compared with 20 Korean patients (14 male and 6 female) and 25 Caucasian appendicitis patients (16 male and 9 female). Two to six blood specimens were collected from all patients at the following times : just before a regularly scheduled infusion and at 0.5 hour after the end of a 0.5 hour infusion. Nonparametric expected maximum(NPEM) algorithm for population modeling was used. The estimated parameters were the elimination rate constant(K), the slope(KS) of the relationship between K versus creatinine clearance(Ccr), the apparent volume of distribution (V), the slope(VS) of the relationship between V versus weight, gentamicin clearance(CL) and the slope(CS) of the relationship between CL versus Ccr and the V. The output includes two marginal probability density function(PDF), means, medians, modes, variance, skewness, kurtosis, and CV%. The mean K(KS) were$0.402{\pm}0.129hr^{-1}$ ($0.00486{\pm}0.00197[hr{\cdot}mL/min/1.73m^2]^{-1}$) and $0.425{\pm}0.137hr^{-1}$($0.00432{\pm}0.00168[hr{\cdot}mL/min/1.73m^2]^{-1}$) for Korean and Caucasian populations, respectively. The mean V(VS) were not different at $14.3{\pm}3.69L$($0.241{\pm}0.0511L/kg$) and $15.8{\pm}4.81L$($0.236{\pm}0.0531L/kg$) for Korean and Caucasian populations, respectively (P>0.2). The mean CL(CS) were $5.68{\pm}1.69L/hr$ ($0.0714{\pm}0.0222L/kg[hr{\cdot}mL/min/1.73m^2]$) and $6.29{\pm}1.84L/hr$ ($0.0629{\pm}0.0189L/kg[hr{\cdot}mL/min/1.73m^2]$) for Korean and Caucasian populations, respectively. There are no differences in gentamicin pharmacokinetics between Korean and Caucasian appendicitis patients.