• Title/Summary/Keyword: Skewed Distribution

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Bit-map-based Spatial Data Transmission Scheme

  • OH, Gi Oug
    • Journal of the Korea Society of Computer and Information
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    • v.24 no.8
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    • pp.137-142
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    • 2019
  • This paper proposed bitmap based spatial data transmission scheme in need of rapid transmission through network in mobile environment that use and creation of data are frequently happen. Former researches that used clustering algorithms, focused on providing service using spatial data can cause delay since it doesn't consider the transmission speed. This paper guaranteed rapid service for user by convert spatial data to bit, leads to more transmission of bit of MTU, the maximum transmission unit. In the experiment, we compared arithmetically default data composed of 16 byte and spatial data converted to bitmap and for simulation, we created virtual data and compared its network transmission speed and conversion time. Virtual data created as standard normal distribution and skewed distribution to compare difference of reading time. The experiment showed that converted bitmap and network transmission are 2.5 and 8 times faster for each.

Force transfer mechanism in positive moment continuity details for prestressed concrete girder bridges

  • Hossain, Tanvir;Okeil, Ayman M.
    • Computers and Concrete
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    • v.14 no.2
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    • pp.109-125
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    • 2014
  • The force transfer mechanism in positive moment continuity details for prestressed concrete girder bridges is investigated in this paper using a three-dimensional detailed finite element model. Positive moment reinforcement in the form of hairpin bars as recommended by the National Cooperative Highway Research Program Report No 519 is incorporated in the model. The cold construction joint that develops at the interface between girder ends and continuity diaphragms is also simulated via contact elements. The model is then subjected to the positive moment and corresponding shear forces that would develop over the service life of the bridge. The stress distribution in the continuity diaphragm and the axial force distribution in the hairpin bars are presented. It was found that due to the asymmetric configuration of the hairpin bars, asymmetric stress distribution develops at the continuity diaphragm, which can be exacerbated by other asymmetric factors such as skewed bridge configurations. It was also observed that when the joint is subjected to a positive moment, the tensile force is transferred from the girder end to the continuity diaphragm only through the hairpin bars due to the lack of contact between the both members at the construction joint. As a result, the stress distribution at girder ends was found to be concentrated around the hairpin bars influence area, rather than be resisted by the entire girder composite section. Finally, the results are used to develop an approach for estimating the cracking moment capacity at girder ends based on a proposed effective moment of inertia.

A Study of the effective approach method for median control chart of non-normally distributed process (비정규분포공정에서 계량치관리를 위한 메디안 특수 관리도의 모형설계와 그 적용에 관한 실용에 연구)

  • 신용백
    • Journal of the Korean Professional Engineers Association
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    • v.21 no.4
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    • pp.19-32
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    • 1988
  • Whereas is non-symmetrical distribution manufacturing process the traditional X-chart by Shewhart is not plotted relatively on the central line but plotted on the skew of upper-hand side or lower-hand side. That is to say, for the purpose of producing either upper-specification-oriented items or lower-specification-oriented items, and when we carry out tighter control so as to have them pass only its specifications, the distribution shape naturally has a non-normal distribution. In the Shewhart X-chart, which is the most widely used one in Korea, such skewed distributions make tile plots to be inclined below or above the central line or outside the control limits although no assignable causes can be found. To overcome such short comings is non-normally distributed processes, a distribution-free type of confidence interval can be used, which should be haled on order statistics. This thesis is concerned with the design of control chart based on a sample median which is easy to use in practical situation and therefore properties for non-normal distributions, such as Gamma, Beta, Lognormal, Weibull, Pareto, and Truncated-normal distributions, may be easily analyzed. To enhance this improvement, I proved the property of practical applications of control chart method by comparing and analyzing the case studies of practical application of special purpose control chart method, and also by introducing the new designed median control chart.

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Distribution of Private Medical Practitioners' Income from Medical Insurance and its determinants (의원의 의료보험진료비 수입분포와 그 결정요인)

  • 서수교;박재용
    • Health Policy and Management
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    • v.5 no.1
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    • pp.1-30
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    • 1995
  • This study was conducted to investigate the distribution of private medical practitioners' income from the medical insurance and its determinants. Total amount of the medical service fee paid by the medical insurance to 1,268 private clinics(767 in Taegu and 510 in Kyungpook that had been in practice at least for one year) in 1993 was compared by the characteristics of practitioner, clinic, patient and population. The practitioners in 40-49 years of age and 6-10 years inpractice had the highest income. Total income of a clinic was increased with the number of physicians, employees and equipments. The largest income differentials were observed among obstetrics and gynecology clinics and the least differentials were among pediatrics clinics. The characteristics of practitioner, clinic and population accounted for 41.7% of the total variance of income. The important determinants of income were specialty of the clinic, age of the practitioner and number of the employee and equipments. The large income differentials among clinics imply a skewed distribution of patients and thus long waiting time, inefficient utilization of manpower and inadequate quality of care. Effective measures to reduce the income differentials need to be developed.

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The Influence of Hardwood Interspecific Competition on Stand Structure and Dynamics for Loblolly Pine Plantations

  • Lee, Young-Jin;Cho, Hyun-Je;Kim, Dong-Geun;Bae, Kwan-Ho;Joo, Sung-Hyun;Hong, Sung-Cheon
    • The Korean Journal of Ecology
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    • v.24 no.4
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    • pp.213-217
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    • 2001
  • The purpose of this study is to investigate the effects of hardwood competitions in stand structure and dynamics by applying prediction models for unthinned loblolly pine (Pinus taeda L.) plantations. A parameter recovery procedure for the Weibull distribution function based on four percentile equations was applied to develop diameter distribution prediction models. Four percentiles of the cumulative diameter distribution prediction equations were predicted as a function of quadratic mean diameter plus competin hardwood trees perhectare varibales. According to the results of this study. it was found that as the amount of competing hardwood trees increased, diameter distributions in terms of stand structure dynamics tended to be more skewed to the right. Therefore, the influence of non-planted hardwood trees interspecific competitoin on planted loblolly pines showed negative effects on the stand structure and dynamics.

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The fundamental frequency (f0) distribution of American speakers in a spontaneous speech corpus

  • Byunggon Yang
    • Phonetics and Speech Sciences
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    • v.16 no.1
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    • pp.11-16
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    • 2024
  • The fundamental frequency (f0), representing an acoustic measure of vocal fold vibration, serves as an indicator of the speaker's emotional state and language-specific pattern in daily conversations. This study aimed to examine the f0 distribution in an English corpus of spontaneous speech, establishing normative data for American speakers. The corpus involved 40 participants engaging in free discussions on daily activities and personal viewpoints. Using Praat, f0 values were collected filtering outliers after removing nonspeech sounds and interviewer voices. Statistical analyses were performed with R. Results indicated a median f0 value of 145 Hz for all the speakers. The f0 values for all speakers exhibited a right-skewed, pointy distribution within a frequency range of 216 Hz from 75 Hz to 339 Hz. The female f0 range was wider than that of males, with a median of 113 Hz for males and 181 Hz for females. This spontaneous speech corpus provides valuable insights for linguists into f0 variation among individuals or groups in a language. Further research is encouraged to develop analytical and statistical measures for establishing reliable f0 standards for the general population.

An improved fuzzy c-means method based on multivariate skew-normal distribution for brain MR image segmentation

  • Guiyuan Zhu;Shengyang Liao;Tianming Zhan;Yunjie Chen
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.18 no.8
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    • pp.2082-2102
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    • 2024
  • Accurate segmentation of magnetic resonance (MR) images is crucial for providing doctors with effective quantitative information for diagnosis. However, the presence of weak boundaries, intensity inhomogeneity, and noise in the images poses challenges for segmentation models to achieve optimal results. While deep learning models can offer relatively accurate results, the scarcity of labeled medical imaging data increases the risk of overfitting. To tackle this issue, this paper proposes a novel fuzzy c-means (FCM) model that integrates a deep learning approach. To address the limited accuracy of traditional FCM models, which employ Euclidean distance as a distance measure, we introduce a measurement function based on the skewed normal distribution. This function enables us to capture more precise information about the distribution of the image. Additionally, we construct a regularization term based on the Kullback-Leibler (KL) divergence of high-confidence deep learning results. This regularization term helps enhance the final segmentation accuracy of the model. Moreover, we incorporate orthogonal basis functions to estimate the bias field and integrate it into the improved FCM method. This integration allows our method to simultaneously segment the image and estimate the bias field. The experimental results on both simulated and real brain MR images demonstrate the robustness of our method, highlighting its superiority over other advanced segmentation algorithms.

Statistical investigation on size distribution of suspended cohesive sediment (점착성 부유사의 입도분포형 검증)

  • Park, Byeoungeun;Byun, Jisun;Son, Minwoo
    • Journal of Korea Water Resources Association
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    • v.53 no.10
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    • pp.917-928
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    • 2020
  • The purpose of this study is to find the appropriate probability distribution representing the size distribution of suspended cohesive sediment. Based on goodness-of-fit test for a significance level of 5% using the Kolmogorov-Smirnov test, it is found that the floc size distributions measured in laboratory experiment and field study show different results. In the case of sample data collected from field experiments, the Gamma distribution is the best fitting form. In the case of laboratory experiment results, the sample data shows the positively-skewed distribution and the GEV distribution is the best fitted. The lognormal distribution, which is generally assumed to be a floc size distribution, is not suitable for both field and laboratory results. By using 3-parameter lognormal distribution, it is shown that similar size distribution with floc size distribution can be simulated.

Estimation on composite lognormal-Pareto distribution based on doubly censored samples (결합 로그노말-파레토 분포에서 추출된 양쪽 중도 절단된 표본을 이용한 모수추정)

  • Lee, Kwang-Ho
    • Journal of the Korean Data and Information Science Society
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    • v.22 no.2
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    • pp.171-177
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    • 2011
  • With the development of the actuarial and insurance industries, the distributions of the insurance payments data are deeply studied by many authors. It is known that theses types of distribution are very highly positively skewed and have a long thick upper tail such as Pareto or lognormal distribution. In 2005, Cooray and Ananda proposed a new model which is composed lognormal distribution and Pareto distribution. They said it as composite lognormal-Preto distribution. They showed that the proposed distribution was better fitted than lognormal or Pareto distribution. On the other hand many agreements about the insurance payment have some options for a trivially small payment or extremely large one because of the limits of total payment. Appling these cases, in this paper we consider the parameter estimation on the composite lognormal-Pareto distribution based on doubly censored samples.

The Marshall-Olkin generalized gamma distribution

  • Barriga, Gladys D.C.;Cordeiro, Gauss M.;Dey, Dipak K.;Cancho, Vicente G.;Louzada, Francisco;Suzuki, Adriano K.
    • Communications for Statistical Applications and Methods
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    • v.25 no.3
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    • pp.245-261
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    • 2018
  • Attempts have been made to define new classes of distributions that provide more flexibility for modelling skewed data in practice. In this work we define a new extension of the generalized gamma distribution (Stacy, The Annals of Mathematical Statistics, 33, 1187-1192, 1962) for Marshall-Olkin generalized gamma (MOGG) distribution, based on the generator pioneered by Marshall and Olkin (Biometrika, 84, 641-652, 1997). This new lifetime model is very flexible including twenty one special models. The main advantage of the new family relies on the fact that practitioners will have a quite flexible distribution to fit real data from several fields, such as engineering, hydrology and survival analysis. Further, we also define a MOGG mixture model, a modification of the MOGG distribution for analyzing lifetime data in presence of cure fraction. This proposed model can be seen as a model of competing causes, where the parameter associated with the Marshall-Olkin distribution controls the activation mechanism of the latent risks (Cooner et al., Statistical Methods in Medical Research, 15, 307-324, 2006). The asymptotic properties of the maximum likelihood estimation approach of the parameters of the model are evaluated by means of simulation studies. The proposed distribution is fitted to two real data sets, one arising from measuring the strength of fibers and the other on melanoma data.