Журнал биометрии и биостатистики

In many scientific fields such as biology (orientation of birds), geology (orientations of feldspar laths) and meteorology (wind direction and ozone concentration), data occur as angular forms. In this paper, a class of wrapped distribution called wrapped generalized Gompertz distributions are introduced (WGG). Characteristic function and fundamental properties of this distribution are described. Some theorems that relate the distribution to some other circular distributions are established. Applications to density estimation and goodness-of-fit tests are used to analyze data on the heading of orientation of the nest of noisy scrub birds, and it is shown that the model fits much better than some other existing circular symmetric and non-symmetric models.

In this paper we study semi-parametric inference procedure for accelerated failure time models with auxiliary information about a main exposure variable. We use a kernel smoothing method to introduce the auxiliary covariate to the likelihood function. The regression parameters are then estimated through maximization of the estimated likelihood function. A consistent estimator of the variance of the estimator of the regression coefficients is proposed. Simulation studies show that the efficiency gain is remarkable when compared to just using the validation sample. The method is applied to the PBC data from the Mayo Clinic trial in primary biliary cirrhosis as an illustration.

Multi-biometric system stores multiple templates for the same user corresponding to the different biometric sources. Infallible security should be provided to the stored biometric templates as biometric is not revocable. In this work, multi-modal biometric template security for palmprint and fingerprint is proposed which is based on the fuzzy vault generation. At first, the preprocessing steps are applied and subsequently, the features are extracted and combined. For recognition, we match the feature vectors of images. The multi-modal biometric template along with the input key are used to generate the fuzzy vault. In the decoding process, the template is given as input and is combined with the stored fuzzy vault to generate the corresponding final key. The experimentation is carried out using CASIA database for palmprint and FVC 2004 database for fingerprint. The evaluation metrics have FMR and FNMR value parameters.