Bayes Estimation of Shift Point in Geometric Sequence

A sequence of independent lifetimes X ₁, X ₂,…, X _m , X _m+1,… X _n were observed from geometric population with parameter q ₁ but later it was found that there was a change in the system at some point of time m and it is reflected in the sequence after X _m by change in parameter q ₂. The Bayes estimates of m, q ₁, q ₂, reliability R ₁ (t) and R ₂ (t) at time t are derived for symmetric and asymmetric loss functions under informative and non informative priors. A simulation study is carried out.     

Maximum Likelihood Estimation in Compound Geometric Failure Model with Changing Parameters From Type-I Two-Stage Progressively Censored and Group Censored Samples

Boardman and Kendell (1970 Boardman , T. J. , Kendell , P. J. ( 1970 ). Estimation in compound failure models . Technometrics 12 : 891 – 908 .[Taylor & Francis Online], [Web of Science ®] , [Google Scholar]) considered the problem of estimation with respect to Type-I censoring when an item is subjected to only one of the two causes of failure assuming exponential model. Patel and Gajjar (1992 Patel , M. N. , Gajjar , A. V. ( 1992 ). Maximum likelihood estimation in compound exponential failure model with changing failure rates from Type-I progressively censored and group censored samples . Commun. Statist. Theor. Meth. 21 ( 10 ): 2899 – 2908 .[Taylor & Francis Online], [Web of Science ®] , [Google Scholar]) considered extension of the Boardman and Kendell's results in case of two-stage progressive censoring. Here we have considered geometric competing risk failure model with two independent causes of failures. Maximum likelihood estimation of the parameters is carried out using Type-I two-stage progressively censored and group censored samples. Asymptotic standard errors of the estimators are obtained for both the cases. Two illustrative examples are cited for ungroup and group competing risk models.     

The Role of Perceived Voice and Speech Characteristics in Vocal Emotion Communication

Aiming at a more comprehensive assessment of nonverbal vocal emotion communication, this article presents the development and validation of a new rating instrument for the assessment of perceived voice and speech features. In two studies, using two different sets of emotion portrayals by German and French actors, ratings of perceived voice and speech characteristics (loudness, pitch, intonation, sharpness, articulation, roughness, instability, and speech rate) were obtained from non-expert (untrained) listeners. In addition, standard acoustic parameters were extracted from the voice samples. Overall, highly similar patterns of results were found in both studies. Rater agreement (reliability) reached highly satisfactory levels for most features. Multiple discriminant analysis results reveal that both perceived vocal features and acoustic parameters allow a high degree of differentiation of the actor-portrayed emotions. Positive emotions can be classified with a higher hit rate on the basis of perceived vocal features, confirming suggestions in the literature that it is difficult to find acoustic valence indicators. The results show that the suggested scales (Geneva Voice Perception Scales) can be reliably measured and make a substantial contribution to a more comprehensive assessment of the process of emotion inferences from vocal expression.     

Asymptotic distribution for the order statistics of a truncated one-parameter family of distributions

In this article we have presented some of the asymptotic theorems related to one-truncation parameter family of distributions ? Comparison of performance of different estimators and other inferential problems have been tackled - Also applications of the main results have been given and illustrated their uses with examples.     

Fifth order rotability

In this paper, conditions for a set of points to form a rotatable design of order five in three dimensions have been worked out. These conditions form a basis for obtaining a set of rotatable designs of order five. An attempt has been made to generalise these results with partial success.     

Optimum two stage group-screening with unequal group sizes and with errors in decisions

In this paper, the formula for the expected number of incorrect decisions has been obtained. It is assumed that the factors are defective with different a-priori probabilities. Group-screening designs have been described which minimise (i) the expected number of runs for a fixed value of the expected number of incorrect decisions, (ii) the expected total cost.