Marginal model is one of the approaches that can be used in analyzing longitudinal data. In this ... more Marginal model is one of the approaches that can be used in analyzing longitudinal data. In this model, to obtain valid inference, correlations between responses of the same individuals are considered as parameters to be estimated. The various marginal models for analyzing longitudinal data with binary responses such as marginal models with marginal odds ratio. conditional odds ratio, dependence ratio, multivariate probit and the method of generalized estimating equations (GEE) are reviewed and compared. Some residuals for examining ...
Eastern Mediterranean health journal = La revue de santé de la Méditerranée orientale = al-Majallah al-ṣiḥḥīyah li-sharq al-mutawassiṭ
To identify the incidence rate and risk factors of neonatal hypothermia at referral hospitals in ... more To identify the incidence rate and risk factors of neonatal hypothermia at referral hospitals in Tehran, Islamic Republic of Iran, 900 neonates were randomly selected. Body temperature was measured repeatedly at different time points after birth. More than 50% became hypothermic soon after birth. Multiple regression analysis showed that low birth weight, low gestational age environmental temperature, low Apgar score, multiple pregnancy and receiving cardiopulmonary resuscitation were significantly associated with hypothermia. These findings suggested that there is an urgent need to sensitize and educate all levels of staff dealing with neonates in our country.
A first-order transition model is used to analyze repeated measurement or longitudinal ordinal re... more A first-order transition model is used to analyze repeated measurement or longitudinal ordinal response data to compare several treatments for which measurements for each subject occur both at baseline and at follow-up. The likelihood function is partitioned to make possible the use of existing software for estimating model parameters. Data from a clinical trial illustrate the application of the transition
– A generalized ,Heckman ,model ,is used ,for the joint modeling ,of longitudinal ,continuous res... more – A generalized ,Heckman ,model ,is used ,for the joint modeling ,of longitudinal ,continuous responses,and ,dropout ,in order ,to see ,the influence of a ,small perturbation of the ,elements ,of the covariance,structure on displacement ,of the ,likelihood. The perturbation from ,random ,dropout ,in the direction of informative dropout is considered for Mastitis data. Keywords –Longitudinal data, Informative dropout, Sensitivity
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2008
Electrode potential of 6-(2,3-dihydro-1,3-dioxo-2-phenyl-1H-inden-2-yl)-2,3-dihydroxybenzaldehyde... more Electrode potential of 6-(2,3-dihydro-1,3-dioxo-2-phenyl-1H-inden-2-yl)-2,3-dihydroxybenzaldehyde (DPDB) in methanol have been calculated theoretically. For the achievement of this task, the density functional theory (B3LYP/6-31G(d)) was employed with the inclusion of the entropic and thermochemical corrections to yield the free energies of the redox reactions. The electrode potential was also obtained experimentally by means of an electrochemical technique (cyclic voltammetry). The geometric parameters, the vibrational frequency values and the UV spectrum of DPDB and 2-(2,3-dihydro-1,3-dioxo-2-phenyl-1H-inden-2-yl)-5,6-dioxocyclohexa-1,3-dienecarbaldehyde (DPDD is the oxidized form of DPDB), were computed using the same methods. The calculated IR spectrum of DPDB, used for the assignment of the IR frequencies, was observed in the experimental FT-IR spectrum. The correlation between the theoretical and experimental DPDB vibrational frequencies was 0.996. This agreement mutually verified the accuracy of the experimental method and the validity of the applied mathematical model.
Some examples of absurd uniformly minimum variance unbiased estimators are discussed. Two reasons... more Some examples of absurd uniformly minimum variance unbiased estimators are discussed. Two reasons, argued in the litera- ture, for having such estimators are lack of enough information in the available data and property of unbiasedness. In this paper, accepting both of these views, we show that an appropriate choice of loss func- tion using a general concept of unbiasedness leads
Marginal model is one of the approaches that can be used in analyzing longitudinal data. In this ... more Marginal model is one of the approaches that can be used in analyzing longitudinal data. In this model, to obtain valid inference, correlations between responses of the same individuals are considered as parameters to be estimated. The various marginal models for analyzing longitudinal data with binary responses such as marginal models with marginal odds ratio. conditional odds ratio, dependence ratio, multivariate probit and the method of generalized estimating equations (GEE) are reviewed and compared. Some residuals for examining ...
Eastern Mediterranean health journal = La revue de santé de la Méditerranée orientale = al-Majallah al-ṣiḥḥīyah li-sharq al-mutawassiṭ
To identify the incidence rate and risk factors of neonatal hypothermia at referral hospitals in ... more To identify the incidence rate and risk factors of neonatal hypothermia at referral hospitals in Tehran, Islamic Republic of Iran, 900 neonates were randomly selected. Body temperature was measured repeatedly at different time points after birth. More than 50% became hypothermic soon after birth. Multiple regression analysis showed that low birth weight, low gestational age environmental temperature, low Apgar score, multiple pregnancy and receiving cardiopulmonary resuscitation were significantly associated with hypothermia. These findings suggested that there is an urgent need to sensitize and educate all levels of staff dealing with neonates in our country.
A first-order transition model is used to analyze repeated measurement or longitudinal ordinal re... more A first-order transition model is used to analyze repeated measurement or longitudinal ordinal response data to compare several treatments for which measurements for each subject occur both at baseline and at follow-up. The likelihood function is partitioned to make possible the use of existing software for estimating model parameters. Data from a clinical trial illustrate the application of the transition
– A generalized ,Heckman ,model ,is used ,for the joint modeling ,of longitudinal ,continuous res... more – A generalized ,Heckman ,model ,is used ,for the joint modeling ,of longitudinal ,continuous responses,and ,dropout ,in order ,to see ,the influence of a ,small perturbation of the ,elements ,of the covariance,structure on displacement ,of the ,likelihood. The perturbation from ,random ,dropout ,in the direction of informative dropout is considered for Mastitis data. Keywords –Longitudinal data, Informative dropout, Sensitivity
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2008
Electrode potential of 6-(2,3-dihydro-1,3-dioxo-2-phenyl-1H-inden-2-yl)-2,3-dihydroxybenzaldehyde... more Electrode potential of 6-(2,3-dihydro-1,3-dioxo-2-phenyl-1H-inden-2-yl)-2,3-dihydroxybenzaldehyde (DPDB) in methanol have been calculated theoretically. For the achievement of this task, the density functional theory (B3LYP/6-31G(d)) was employed with the inclusion of the entropic and thermochemical corrections to yield the free energies of the redox reactions. The electrode potential was also obtained experimentally by means of an electrochemical technique (cyclic voltammetry). The geometric parameters, the vibrational frequency values and the UV spectrum of DPDB and 2-(2,3-dihydro-1,3-dioxo-2-phenyl-1H-inden-2-yl)-5,6-dioxocyclohexa-1,3-dienecarbaldehyde (DPDD is the oxidized form of DPDB), were computed using the same methods. The calculated IR spectrum of DPDB, used for the assignment of the IR frequencies, was observed in the experimental FT-IR spectrum. The correlation between the theoretical and experimental DPDB vibrational frequencies was 0.996. This agreement mutually verified the accuracy of the experimental method and the validity of the applied mathematical model.
Some examples of absurd uniformly minimum variance unbiased estimators are discussed. Two reasons... more Some examples of absurd uniformly minimum variance unbiased estimators are discussed. Two reasons, argued in the litera- ture, for having such estimators are lack of enough information in the available data and property of unbiasedness. In this paper, accepting both of these views, we show that an appropriate choice of loss func- tion using a general concept of unbiasedness leads
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