Search

We perform a Bayesian analysis of the upper trunacated Zeghdoudi distribution based on type II censored data. Using various loss functions including the generalised quadratic, entropy and Linex functions, we obtain Bayes estimators and the corresponding posterior risks. As tractable analytical forms of these estimators is out of reach, we propose the use of simulations based on Markov chain Monte-carlo methods to study their performance. Given nitial values of model parameters, we also obtain maximum likelihood estimators. Using Pitmanw closeness criterion and integrated mean square error we compare their performance with those of the Bayesian estimators. Finally, we illustrate our approach through an example using a set of real data.

In this paper we investigate the estimation of the unknown parameters of a competing risk model based on a Weibull distributed decreasing failure rate and an exponentially distributed constant failure rate, under right censored data.likelihood estimators., 20 pages, 4 figures

A cross-sectional study was undertaken to determine the prevalence of bovine mastitis, and to assess potential risk factors among lactating cows, both local and crossbreeds, in and around Eltarf town in northeast Algeria. A total of 324 lactating cows were included in the survey, examined for mastitis by clinical examination of the udder and teats and tested using the California Mastitis Test (CMT) to determine clinical and subclinical mastitis. Data was collected in a questionnaire during the farm visit. The overall prevalence was 41.66% (135/324), of which 9.80% (32/324) were clinical and 31.79% (103/324) subclinical cases. Out of 1296 quarters examined, the prevalence rate was 41.04% (532/1296), where 9.25% (120/1296) were clinical and 31.79% (412/1296) subclinical aspects of mastitis. Right Hind teats (RH) showed the highest rate of inflammation (51.54%), followed by the Left Hind (LH) teat in second place (44.44%), Right front quarter (RF; 36.11%) and lastly Left Front (LF; 32.09%). The relationships of risk factors with mastitis status were determined using Chi-square analysis, associations between mastitis and the independent variables, including parity and hygienic condition of the udder, teat and housing of cows were statistically significant (P0.05). This study indicated that mastitis is a prevalent disease and a serious problem across herds in and around the Eltarf district in Algeria. Further detailed epidemiological, microbiological, and economic analysis studies are required at the national level to tailor existing control and prevention strategies. Regular surveillance measures are recommended., Istraživanje je provedeno da bi se ustvrdila prevalencija i procijenili potencijalni čimbenici rizika za mastitis u krava u laktaciji u gradu Eltarf i njegovoj okolici, u sjeveroistočnom Alžiru u križanih i lokalnih pasmina krava. Tri stotine i dvadeset četiri krava u laktaciji bile su uključeno u istraživanje mastitisa kliničkim pregledom vimena i sisa i testirano uporabom kalifornijskog mastitis testa (CMT) kako bi se ustvrdio klinički i supklinički oblik mastitisa. Anketa za prikupljanje podataka prikupljena je tijekom posjete farmi. Ukupni postotak prevalencije na razini krave iznosio je 41,66 % (135/324), od čega su 9,80 % (32/324) bili klinički i 31,79 % (103/324) supklinički oblici mastiitisa. Od ukupno 1296 pregledanih četvrti, postotak prevalencije iznosio je 41,04 % (532/1296), od čega su 9,25 % (120/1296) bili klinički, a 31,79 % (412/1296) supklinički oblici mastitisa. Najveći postotak infekcije (51,54 %) zabilježen je u desnoj stražnjoj četvrti vimena (RH), zatim u lijevoj zadnjoj četvrti (LH) (44,44 %), potom u prednjoj desnoj četvrti (RF) (36,11 %), a najmanji postotak infekcije je zabilježen u lijevoj prednjoj četvrti vimena (LF) (32,09 %). Povezanost čimbenika rizika s pojavnosti mastitisa ustvrđena je primjenom Chi-kvadrat analize, povezanosti između neovisne varijable, uključujući paritet i higijensko stanje vimena i sisa te smještaja krava s mastitisom, bili su statistički značajni (P0,05). Ova studija pokazala je da je mastitis rasprostranjena bolest i ozbiljan problem u mnogim stada u gradu Eltarf i njegovoj okolici u sjeveroistočnom Alžiru. Nužne su daljnje detaljne epidemiološke, mikrobiološke i ekonomske analize na razini cijele države da bi se prilagodila postojeća strategija kontrole i prevencije mastitisa te se preporučuju redovite mjere njegovog nadzora.

Consider a system with lifetime governed by a bivariate exponential model (X; Y ). Using the maximum likelihood method and the Bayesian approach, we estimate the parameters and the mean time between failure (MTBF) of this model.To compare the estimators, an exhaustive Monte Carlo study is performed using the Pitman closeness cri- terion and the relative eciency. Key words: Bayesian Analysis; Bivariate Exponential Model; Loss function; Maximum Likelihood Estimation; Reliability.