This study is based on samples taken from one of the main branches of Tigris River; Gharaf River, at Kut Barrage in Wasit Governorate, Iraq. It aimes to study the quantity and quality of the mollusca Invertebrates; furthermore. The study evaluates the molluscan biodiversity of the rivers by using appropriate biodiversity indexes. Thus, the first of its kind study in the evaluation of the diversity of mollusc in Gharaf River assemblage. Monthly samples were collected randomly from the river mud, for 12 months, from January till December 2016. During the collection process; 5 stations on the river were chosen for sampling with 10(±1) Km distance between each of the stations, including Wasit Governorate. The study showed the presence of 20 Molluscs species were recorded for the first time in Gharaf River. In terms of population density, the annual average for Molluscs was 686.34 Ind./m2 . Relative Abundance Index (Ra) showed that Melanoid tuberculate, Physa acuta and Lymnaea auricularia was less abundant species in Gharaf River. According to the Constancy Index (S) Corbicula fluminalis, M. tuberculata, M. nodosa, Theodoxus jordani, L. auricularia and Physa acuta considered as constancy species in Gharaf’s environment. The highest recorded values of the Species Richness index were 0.0303, while the lowest values were a complete absence (zero). Regarding Jaccard Presence-Community, the results demonstrated that the highest similarity percentage between mollusca communities in Gharraf River was between stations 3 and 5, recorded at 66.66%. In the case of the Shannon-Weiner Diversity Index (H), the diversity values in Gharaf peaked at 7.819 bit/Ind. and a complete absence (zero) at its lowest point. However, the Species Uniformity Index (E) results revealed the highest uniformity values was 1, while, the lowest values were complete absence (zero).
The present paper concerns with the problem of estimating the reliability system in the stress – strength model under the consideration non identical and independent of stress and strength and follows Lomax Distribution. Various shrinkage estimation methods were employed in this context depend on Maximum likelihood, Moment Method and shrinkage weight factors based on Monte Carlo Simulation. Comparisons among the suggested estimation methods have been made using the mean absolute percentage error criteria depend on MATLAB program.
In this paper, Bayes estimators for the shape and scale parameters of Gamma distribution under the Entropy loss function have been obtained, assuming Gamma and Exponential priors for the shape and scale parameters respectively. Moment, Maximum likelihood estimators and Lindley’s approximation have been used effectively in Bayesian estimation. Based on Monte Carlo simulation method, those estimators are compared depending on the mean squared errors (MSE’s). The results show that, the performance of the Bayes estimator under Entropy loss function is better than other estimates in all cases.
The Boltzmann equation has been solved using (EEDF) package for a pure sulfur hexafluoride (SF6) gas and its mixtures with buffer Helium (He) gas to study the electron energy distribution function EEDF and then the corresponding transport coefficients for various ratios of SF6 and the mixtures. The calculations are graphically represented and discussed for the sake of comparison between the various mixtures. It is found that the various SF6 – He content mixtures have a considerable effect on EEDF and the transport coefficients of the mixtures
Most of the Weibull models studied in the literature were appropriate for modelling a continuous random variable which assumes the variable takes on real values over the interval [0,∞]. One of the new studies in statistics is when the variables take on discrete values. The idea was first introduced by Nakagawa and Osaki, as they introduced discrete Weibull distribution with two shape parameters q and β where 0 < q < 1 and b > 0. Weibull models for modelling discrete random variables assume only non-negative integer values. Such models are useful for modelling for example; the number of cycles to failure when components are subjected to cyclical loading. Discrete Weibull models can be obta
... Show Moreالمتغير العشوائي X له توزيع أسي اذا كان له دالة احتمالية الكثافة بالشكل:
عندما ، هذه هي الحالة الخاصة لتوزيع كاما.
غالباً جداً ولسبب معقول تأخذ . الحالة الخاصة لـ (1) التي نحصل عليها تسمى بالتوزيع الاسي لمعلمة واحدة.
اذا كانت ، ، التوزيع في هذه الحالة يسمى التوزيع الاسي القياسي
اما بالنسب
... Show MoreWeibull Distribution is one of most important distribution and it is mainly used in reliability and in distribution of life time. The study handled two parameter and three-parameter Weibull Distribution in addition to five –parameter Bi-Weibull distribution. The latter being very new and was not mentioned before in many of the previous references. This distribution depends on both the two parameter and the three –parameter Weibull distributions by using the scale parameter (α) and the shape parameter (b) in the first and adding the location parameter (g)to the second and then joining them together to produce a distribution with five parameters.
... Show MoreIn this paper a new idea was introduced which is finding a new distribution from other distributions using mixing parameters; wi where 0 < wi < 1 and . Therefore we can get many mixture distributions with a number of parameters. In this paper I introduced the idea of a mixture Weibull distribution which is produced from mixing two Weibull distributions; the first with two parameters, the scale parameter , and the shape parameter, and the second also has the scale parameter , and the shape parameter, in addition to the location parameter, . These two distributions were mixed using a new parameter which is the mixing parameter w which represents the proportion
... Show MoreWeibull Distribution is one of most important distribution and it is mainly used in reliability and in distribution of life time. The study handled two parameter and three-parameter Weibull Distribution in addition to five –parameter Bi-Weibull distribution. The latter being very new and was not mentioned before in many of the previous references. This distribution depends on both the two parameter and the three –parameter Weibull distributions by using the scale parameter (α) and the shape parameter (b) in the first and adding the location parameter (g)to the second and then joining them together to produce a distribution with five parameters.
... Show MoreThe novels that we have addressed in the research, Including those with the ideological and political ideology, It's carry a negative image for the Kurds without any attempt to understand, empathy and the separation between politics and the people, The novels were deformation of the image, Like tongue of the former authority which speaks their ideas, Such as (Freedom heads bagged, Happy sorrows Tuesdays for Jassim Alrassif, and Under the dogs skies for Salah Salah). The rest of novels (Life is a moment for Salam Ibrahim, The country night for Jassim Halawi, The rib for Hameed Aleqabi). These are novels contained a scene carries a negative image among many other social images, some positive, and can be described as neutral novels. We can
... Show MoreSmart cities are using innovative technological solutions to improve the quality of life and service that citizens and visitors receive. Defined as a digital or ecological city, its services depend on information and communication technology infrastructure, such as intelligent automated traffic systems, advanced security management Services, building systems, and the use of automation in offices and homes. The global trend now towards smart cities, sustainable and green cities and other cities, with different nomenclature, the common denominator is the comfort of the individual and the preservation of natural resources. Adopting smart, sustainable, green, or healthy cities is either t