• 제목/요약/키워드: Statistical parameters

검색결과 2,668건 처리시간 0.044초

음향신호의 분석에 의한 후두질환의 진단에 관한 연구 (A Study on the Diagnosis of Laryngeal Diseases by Acoustic Signal Analysis)

  • 조철우;양병곤;왕수건
    • 음성과학
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    • 제5권1호
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    • pp.151-165
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    • 1999
  • This paper describes a series of researches to diagnose vocal diseases using the statistical method and the acoustic signal analysis method. Speech materials are collected at the hospital. Using the pathological database, the basic parameters for the diagnosis are obtained. Based on the statistical characteristics of the parameters, valid parameters are chosen and those are used to diagnose the pathological speech signal. Cepstrum is used to extract parameters which represents characteristics of pathological speech. 3 layered neural network is used to train and classify pathological speech into normal, benign and malignant case.

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Modified inverse moment estimation: its principle and applications

  • Gui, Wenhao
    • Communications for Statistical Applications and Methods
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    • 제23권6호
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    • pp.479-496
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    • 2016
  • In this survey, we present a modified inverse moment estimation of parameters and its applications. We use a specific model to demonstrate its principle and how to apply this method in practice. The estimation of unknown parameters is considered. A necessary and sufficient condition for the existence and uniqueness of maximum-likelihood estimates of the parameters is obtained for the classical maximum likelihood estimation. Inverse moment and modified inverse moment estimators are proposed and their properties are studied. Monte Carlo simulations are conducted to compare the performances of these estimators. As far as the biases and mean squared errors are concerned, modified inverse moment estimator works the best in all cases considered for estimating the unknown parameters. Its performance is followed by inverse moment estimator and maximum likelihood estimator, especially for small sample sizes.

Improvement of Support Vector Clustering using Evolutionary Programming and Bootstrap

  • Jun, Sung-Hae
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • 제8권3호
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    • pp.196-201
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    • 2008
  • Statistical learning theory has three analytical tools which are support vector machine, support vector regression, and support vector clustering for classification, regression, and clustering respectively. In general, their performances are good because they are constructed by convex optimization. But, there are some problems in the methods. One of the problems is the subjective determination of the parameters for kernel function and regularization by the arts of researchers. Also, the results of the learning machines are depended on the selected parameters. In this paper, we propose an efficient method for objective determination of the parameters of support vector clustering which is the clustering method of statistical learning theory. Using evolutionary algorithm and bootstrap method, we select the parameters of kernel function and regularization constant objectively. To verify improved performances of proposed research, we compare our method with established learning algorithms using the data sets form ucr machine learning repository and synthetic data.

Inference for exponentiated Weibull distribution under constant stress partially accelerated life tests with multiple censored

  • Nassr, Said G.;Elharoun, Neema M.
    • Communications for Statistical Applications and Methods
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    • 제26권2호
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    • pp.131-148
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    • 2019
  • Constant stress partially accelerated life tests are studied according to exponentiated Weibull distribution. Grounded on multiple censoring, the maximum likelihood estimators are determined in connection with unknown distribution parameters and accelerated factor. The confidence intervals of the unknown parameters and acceleration factor are constructed for large sample size. However, it is not possible to obtain the Bayes estimates in plain form, so we apply a Markov chain Monte Carlo method to deal with this issue, which permits us to create a credible interval of the associated parameters. Finally, based on constant stress partially accelerated life tests scheme with exponentiated Weibull distribution under multiple censoring, the illustrative example and the simulation results are used to investigate the maximum likelihood, and Bayesian estimates of the unknown parameters.

시변환 스트레스 조건에서의 와이블 분포의 모수 및 가속 모수에 대한 베이시안 추정을 사용하는 이산 시간 접근 방법 (A Discrete Time Approximation Method using Bayesian Inference of Parameters of Weibull Distribution and Acceleration Parameters with Time-Varying Stresses)

  • 정인승
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회A
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    • pp.1331-1336
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    • 2008
  • This paper suggests a method using Bayesian inference to estimate the parameters of Weibull distribution and acceleration parameters under the condition that the stresses are time-dependent functions. A Bayesian model based on the discrete time approximation is formulated to infer the parameters of interest from the failure data of the virtual tests and a statistical analysis is considered to decide the most probable mean values of the parameters for reasoning of the failure data.

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Program Development of Genetic Analysis for Diallel Cross Experiment

  • Kim, Seo Young;Bae, Jong Sung
    • Communications for Statistical Applications and Methods
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    • 제9권3호
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    • pp.675-682
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    • 2002
  • In this study, we develop the statistical analysis program for genetic analysis of diallel crosses data by SAS/MACRO, SAS/IML. Genetic analysis is to estimate of genetics parameters and heredity with reciprocal cross and without reciprocal cross. Statistical analysis program solve the problem of the difficulties on the data analysis in field denetics and breeding Therefore the user whoever want to analysis of data on genetics and breeding easily conduct the work saving time and suffering.

세라믹 복합체의 굽힘강도 데이터의 통계적분석 : 와이블 형상모수의 추정과 비교를 중심으로 (Statistical Analysis of Bending-Strength Data of Ceramic Matrix Composites : Estimation of Weibull Shape Parameter)

  • 전영록
    • 한국신뢰성학회지:신뢰성응용연구
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    • 제1권1호
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    • pp.17-33
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    • 2001
  • The characteristics of Weibull distribution are investigated as a function of shape parameter. The statistical estimation methods of the shape parameter and statistical comparison methods of two or more shape parameters are studied. Assuming Weibull distribution, statistical analysis of bending-strength data of alumina titanium carbide ceramic matrix composites machined two different methods are performed.

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Statistical Correction of Numerical Model Forecasts for Typhoon Tracks

  • Sohn, Keon-Tae
    • Communications for Statistical Applications and Methods
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    • 제12권2호
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    • pp.295-304
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    • 2005
  • This paper concentrates on the prediction of typhoon tracks using the dynamic linear model (DLM) for the statistical correction of the numerical model guidance used in the JMA. The DLM with proposed forecast strategy is applied to reduce their systematic errors using the latest observation. All parameters of the DLM are updated dynamically and backward forecasting is performed to remove the effect of initial values.

Probabilistic structural damage detection approaches based on structural dynamic response moments

  • Lei, Ying;Yang, Ning;Xia, Dandan
    • Smart Structures and Systems
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    • 제20권2호
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    • pp.207-217
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    • 2017
  • Because of the inevitable uncertainties such as structural parameters, external excitations and measurement noises, the effects of uncertainties should be taken into consideration in structural damage detection. In this paper, two probabilistic structural damage detection approaches are proposed to account for the underlying uncertainties in structural parameters and external excitation. The first approach adopts the statistical moment-based structural damage detection (SMBDD) algorithm together with the sensitivity analysis of the damage vector to the uncertain parameters. The approach takes the advantage of the strength SMBDD, so it is robust to measurement noise. However, it requests the number of measured responses is not less than that of unknown structural parameters. To reduce the number of measurements requested by the SMBDD algorithm, another probabilistic structural damage detection approach is proposed. It is based on the integration of structural damage detection using temporal moments in each time segment of measured response time history with the sensitivity analysis of the damage vector to the uncertain parameters. In both approaches, probability distribution of damage vector is estimated from those of uncertain parameters based on stochastic finite element model updating and probabilistic propagation. By comparing the two probability distribution characteristics for the undamaged and damaged models, probability of damage existence and damage extent at structural element level can be detected. Some numerical examples are used to demonstrate the performances of the two proposed approaches, respectively.

Bayesian Method for Modeling Male Breast Cancer Survival Data

  • Khan, Hafiz Mohammad Rafiqullah;Saxena, Anshul;Rana, Sagar;Ahmed, Nasar Uddin
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권2호
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    • pp.663-669
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    • 2014
  • Background: With recent progress in health science administration, a huge amount of data has been collected from thousands of subjects. Statistical and computational techniques are very necessary to understand such data and to make valid scientific conclusions. The purpose of this paper was to develop a statistical probability model and to predict future survival times for male breast cancer patients who were diagnosed in the USA during 1973-2009. Materials and Methods: A random sample of 500 male patients was selected from the Surveillance Epidemiology and End Results (SEER) database. The survival times for the male patients were used to derive the statistical probability model. To measure the goodness of fit tests, the model building criterions: Akaike Information Criteria (AIC), Bayesian Information Criteria (BIC), and Deviance Information Criteria (DIC) were employed. A novel Bayesian method was used to derive the posterior density function for the parameters and the predictive inference for future survival times from the exponentiated Weibull model, assuming that the observed breast cancer survival data follow such type of model. The Markov chain Monte Carlo method was used to determine the inference for the parameters. Results: The summary results of certain demographic and socio-economic variables are reported. It was found that the exponentiated Weibull model fits the male survival data. Statistical inferences of the posterior parameters are presented. Mean predictive survival times, 95% predictive intervals, predictive skewness and kurtosis were obtained. Conclusions: The findings will hopefully be useful in treatment planning, healthcare resource allocation, and may motivate future research on breast cancer related survival issues.