Text Independent Open-Set Cell phone Identification

This paper discusses the application of speech signals that convey various pieces of information such as the identity of its speaker, the language spoken, and the linguistic information about the text being spoken etc. The rapid developments in technologies related to cell-phones have resulted in their much broader usage than mere talking devices used for making and receiving phone calls. User-generated audio recordings from cell phones can be very helpful in a number of forensic applications. This thesis proposes a novel system for open-set cell-phone identification from speech samples recorded using the cell-phone. The proposed system uses different features based on original speech recordings and classifies them using sequential minimal optimization (SMO) based Support vector machine (SVM) and Vector Quantization (VQ). The performance of the proposed system is tested on a customised databases extracted from pre-recorded speech content of twenty-two cell phones of different manufacturers. Closed-set cell-phone recognition systems abound, and the overwhelming majority of research in cell-phone recognition in the past has been limited to this task. A realistically viable system must be capable of dealing with the open-set task. This effort attacks the open-set task, identifying the best features to use, and proposes the use of a fuzzy classifier followed by hypothesis testing as a model for text-independent, open-set cell-phone recognition

Phylogeography and Population Structure Analysis Reveal Diversity by Gene Flow and Mutation in Ustilago segetum (Pers.) Roussel tritici Causing Loose Smut of Wheat

Ustilago segetum (Pers.) Roussel tritici (UST) causes loose smut of wheat account for considerable grain yield losses globally. For effective management, knowledge of its genetic variability and population structure is a prerequisite. In this study, UST isolates sampled from four different wheat growing zones of India were analyzed using the second largest subunit of the RNA polymerase II (RPB2) and a set of sixteen neutral simple sequence repeats (SSRs) markers. Among the 112 UST isolates genotyped, 98 haplotypes were identified. All the isolates were categorized into two groups (K = 2), each consisting of isolates from different sampling sites, on the basis of unweighted paired-grouping method with arithmetic averages (UPGMA) and the Bayesian analysis of population structure. The positive and significant index of association (IA = 1.169) and standardized index of association (rBarD = 0.075) indicate population is of non-random mating type. Analysis of molecular variance showed that the highest variance component is among isolates (91%), with significantly low genetic differentiation variation among regions (8%) (Fst = 0.012). Recombination (Rm = 0) was not detected. The results showed that UST isolates have a clonal genetic structure with limited genetic differentiation and human arbitrated gene flow and mutations are the prime evolutionary processes determining its genetic structure. These findings will be helpful in devising management strategy especially for selection and breeding of resistant wheat cultivars