Papers by ebrahim yousefi
Journal of Comprehensive Pediatrics, 2021
Objectives: Reducing infant mortality in the whole world is one of the millennium development goa... more Objectives: Reducing infant mortality in the whole world is one of the millennium development goals.The aim of this study was to determine the factors related to infant mortality using data mining algorithms. Methods: This population-based case-control study was conducted in eight provinces of Iran. A sum of 2,386 mothers (1,076 cases and 1,310 controls) enrolled in this study. Data were extracted from health records of mothers and filled with checklists in health centers. We employed several data mining algorithms such as AdaBoost classifier, Support Vector Machine, Artificial Neural Networks, Random Forests, K-nearest neighborhood, and Naïve Bayes in order to recognize the important predictors of infant death; binary logistic regression model was used to clarify the role of each selected predictor. Results: In this study, 58.7% of infant mortalities occurred in rural areas, that 55.6% of them were boys. Moreover, Naïve Bayes and Random Forest were highly capable of predicting rela...
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PLoS ONE, 2018
We developed an unsupervised machine learning algorithm and applied it to big corneal parameters ... more We developed an unsupervised machine learning algorithm and applied it to big corneal parameters to identify and monitor keratoconus stages. A big dataset of corneal swept source optical coherence tomography (OCT) images of 12,242 eyes acquired from SS-1000 CASIA OCT Imaging Systems in multiple centers across Japan was assembled. A total of 3,156 eyes with valid Ectasia Status Index (ESI) between zero and 100% were selected for the downstream analysis. Four hundred and twenty corneal topography, elevation, and pachymetry parameters (excluding ESI Keratoconus indices) were selected. The algorithm included three major steps. 1) Principal component analysis (PCA) was used to linearly reduce the dimensionality of the input data from 420 to eight significant principal components. 2) Manifold learning was used to further reducing the selected principal components nonlinearly to two eigen-parameters. 3) Finally, a density-based clustering was applied to the eigen-parameters to identify eye...
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Performance of hydrological models will depend on how they are calibrated. In these models, the v... more Performance of hydrological models will depend on how they are calibrated. In these models, the value of some parameters can be estimated with direct observations and measures. But some others are not directly observable and their estimations can be carried out by indirect techniques of model fitting in historical data. The main aim of this study is to investigate about the performance of soil moisture accounting model (HMS SMA) in annual, semiannual, seasonal and monthly time scales to estimate the effect of soil moisture on causing of runoff. In this research, after of Zolachay watershed Modeling with Extension HEC-GeoHMS and finally by estimating accounting model parameters of soil moisture, the rainfall- runoff simulation in other scales has been done. By analysis of measures and enhancement of HMS SMA Model parameters, we can claim that monthly time scale in calibration model can work more accurate than seasonal, semiannual, and annual time scales. Regarding the estimation of p...
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Performance of hydrological models will depend on how they are calibrated. In these models, the v... more Performance of hydrological models will depend on how they are calibrated. In these models, the value of some parameters can be estimated with direct observations and measures. But some others are not directly observable and their estimations can be carried out by indirect techniques of model fitting in historical data. The main aim of this study is to investigate about the performance of soil moisture accounting model (HMS SMA) in annual, semiannual, seasonal and monthly time scales to estimate the effect of soil moisture on causing of runoff. In this research, after of Zolachay watershed Modeling with Extension HEC-GeoHMS and finally by estimating accounting model parameters of soil moisture, the rainfall- runoff simulation in other scales has been done. By analysis of measures and enhancement of HMS SMA Model parameters, we can claim that monthly time scale in calibration model can work more accurate than seasonal, semiannual, and annual time scales. Regarding the estimation of p...
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There are several statistical and empirical methods for flood discharge estimation. One of the em... more There are several statistical and empirical methods for flood discharge estimation. One of the empirical methods that were considered in this study was fuller equation. The advantage of fuller equation in compression of other empirical methods is estimation of different periods of flood discharge. In the first step, hydrological missing data generated using SPSS14. In order to continue to use empirical formula for estimating Fuller maximum instantaneous flow rate in different areas, users should calibrate coefficients of equation for each region. In this study, coefficients of fuller formula optimized using non-linear programming model by Lingo. The maximum instantaneous flow rate for the region was estimated to selected stations. The results show that, the regional coefficient (c) is 0.19 and (ß) coefficient for return periods of 2, 5, 10, 25, 50, 100, 200 years are 0, 0. 93, 1.16, 1.38, 1.53, 1.68, 1.84 respectively. Therefore, Fuller formula coefficients (2.66 and -0.3) was calib...
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Papers by ebrahim yousefi