Proposed Generalized Method and Algorithms for the Estimation of Parameters and Best Model Fits of Log Linear Model

The paper is on proposed generalized method and algorithms developed for estimation of parameters and best model fits of log linear model for q-dimensional contingency table. For purpose of this work, the method was used to provide estimates of parameters of log –linear model for five- dimensional contingency table. In estimating these parameters and best model fit, computer programs in R were developed for the implementation of the algorithms. The iterative proportional fitting procedure was used to estimate the parameters and goodness of fits of models of the log linear model.  A real life data was used for illustration and the result obtained showed the best model fit for five dimensional contingency table is [BSGM, BGAM]. This showed that the best model fit has sufficient evidence to fit the data without loss of information. This model has highest p-value and the least likelihood ratio estimate. This model also revealed that state of origin is independent of age given Bscgrade and mode of admission. Keywords:  contingency table  , categorical data, hierarchical log –linear models, Parameters, proposed generalized  method, algorithms,  Iterative proportional fitting  procedure

Information Criteria and Log Linear Models Selection for Contingency Tables

In this paper, Log linear model analysis was used to test the significance of interactions of three categorical variables as well as determining the most parsimonious model that best fit the data. Many approaches exist in model selection;backward elimination method is however used in this work............

Comparative Assessment of the Insecticidal Potency of Tobacco Leaves Extract (Nicotiana Tabacum), Black Pepper Seeds (Uziza) Extract (Piper Guineense) and African Pepper Seeds (Uda) Extract (Xylapia Aetiopica)

The biological insecticide was produced with the extract of nicotiana tabacum (tobacco leaves) extract xylopia actiopica (African pepper (uda) seeds extract and piper guineense (Black pepper seeds (uziza)). These extracts were prepared from three different species of plants indigenous to Nigeria and they were tested for their insecticidal activity against sitophilus zeamais and sitophilus oryzea (weevils) under laboratory conditions at 30oc: 24 hour light/dark regimes (methods / systems). The extracts of xylopica aetiopics and piper guineaense had the highest percentage of mortality (88% and 84%) respectively) when compared with the other treatments. Nicotiana tabacum has the least percentage of morality (70%). When the three extracts were combined at the same ratio it was observed that the percentage of morality of the mixture was significantly higher due to the high frequency of the properties of the three different plants extracts. Keywords: Nicotiana tabacum xylopia actipica and piper guineense, insecticide, morality.