In multimodal biometric systems, human identification is performed by fusing information in different ways like sensor-level, feature-level, score-level, rank-level and decision-level. Score-level fusion is preferred over other levels of fusion because of its low complexity and sufficient availability of information for fusion. However, the scores obtained from different unimodal systems are he...

The Johns Hopkins University Applied Physics Laboratory participated in three of the five tasks of the CLEF-2001 evaluation, monolingual retrieval, bilingual retrieval, and multilingual retrieval. In this paper we describe the fundamental methods we used and we present initial results from three experiments. The first investigation examines whether residual inverse document frequency can improv...

by Jeffrey Richard Paone The biometric menagerie, or biometric zoo, is a classification system used to label the matching tendencies of a given subject’s biometric signature. These tendencies may include matching their own signatures poorly or matching other subjects’ signatures better than their own. Several experiments show the biometric menagerie to be an unstable classification system where...

Generative unigram language models have proven to be a simple though effective model for information retrieval tasks. In contrast to ad-hoc retrieval, topic tracking requires that matching scores are comparable across topics. Several ranking functions based on generative language models: straight likelihood, likelihood ratio, normalized likelihood ratio, and the related Kullback-Leibler diverge...

It is generally conceded that duration variability has huge effects on the biometric performance of speaker recognition systems. State-of-the-art approaches, which employ ivector representations, apply adaptive symmetric (AS) scorenormalizations to improve the performance of the underlying system by using specific statistics on reference and probe templates obtained from additional datasets. Th...

Meta-search, or the combination of the outputs of different search engines in response to a query, has been shown to improve performance. Since the scores produced by different search engines are not comparable, researchers have often decomposed the metasearch problem into a score normalization step followed by a combination step. Combination has been studied by many researchers. While appropri...

The seven citation tones of the Southern Min dialect of Zhangzhou are described impressionistically, and a linguistic-tonetic representation of their acoustics derived from the z-score normalization of the tones of 9 male and 12 female speakers. A normalization of the raw mean tonal data is shown to be slightly superior to a log10 transform, delivering about an eight-fold reduction in the betwe...

Probabilistic Linear Discriminant Analysis (PLDA) has become state-of-the-art method for modeling i-vector space in speaker recognition task. However the performance degradation is observed if enrollment data size differs from one speaker to another. This paper presents a solution to such problem by introducing new PLDA scoring normalization technique. Normalization parameters are derived in a ...