Statistics

University of Calcutta (informally known as Calcutta University or CU) is a collegiate public state university located in Kolkata, West Bengal, India.&nbsp;Within India it is recognized as a &quot;Five-Star University&quot; and accredited &quot;A&quot; Grade by National Assessment and Accreditation Council.

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The University of Calcutta has secured the Fifth position among the Universities of India in the prestigious &quot;Indian University Ranking 2019&quot; list, released by the NIRF of the Ministry of Human Resource Development, Government of India.

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It was established on 24 January 1857, and was one of the first institutions in Asia to be established as a multidisciplinary and Western-style university. Its alumni and faculty include several heads of state, heads of government, social reformers, prominent artists, only academy award winner and Dirac medal winner in India, many Fellows of the Royal Society and five Nobel laureates as of 2019 which is highest in South Asia.

University Of Calcutta

This paper proposes k-medoids clustering method to reveal the distinct groups of 1318 variable stars in the Galaxy based on their light curves, where each light curve represents the graph of brightness of the star against time. To overcome the deficiencies of subjective traditional classification, we separate the stars more scientifically according to their geometrical configuration and show that our approach outperforms the existing classification schemes in astronomy. It results in two optimum groups of eclipsing binaries corresponding to bright, massive systems and fainter, less massive systems. © 2019, © 2019 Informa UK Limited, trading as Taylor &amp; Francis Group.

GENERAL

Applied Mathematics

Fulltext

Journal of Applied Statistics

Unsupervised classification of eclipsing binary light curves through k-medoids clustering

Dengue is one of the deadliest mosquito-borne disease prevalent mainly in tropical and sub-tropical regions. Controlling the spread of this disease becomes a major concern to the public health authority. World Health Organization (WHO) adopted several mosquito control strategies to reduce the disease prevalence. In this work, a general multi-patch non-autonomous dengue model is formulated to capture the temporal and spatial transmission mechanism of the disease and the effectiveness of different adult mosquito control strategies in reducing dengue prevalence is evaluated. During the period (2014&ndash;2015) the dengue situation of Kolkata which is one of the most dengue affected city in India is considered in our study. Depending on geographical location, Kolkata is divided into five regions and our model is fitted to the monthly dengue cases of these five regions during the above-mentioned period. By considering control specific characteristics (e.g. efficacy, environment persistence) of the mosquito control strategies, we study the efficiency of three adult mosquito controls and their combined effect in reducing dengue prevalence. From our study, it is observed that control with higher environment persistence performs better in comparison to the controls having low environment persistence. It is also observed that, connectedness between the regions play a key role in the effectiveness of the control strategies. &copy; 2019 Elsevier Ltd

World University root node

Journal of Theoretical Biology

Impact of adult mosquito control on dengue prevalence in a multi-patch setting: A case study in Kolkata (2014-2015)

A multi-treatment response adaptive procedure is developed considering “comparison with the best” philosophy of multiple comparison procedures for clinical trials with ordinal categorical responses, when there is no shared control. For each response category, we arbitrarily create two outcome groups; one by combining the categories more favorable to it and the other by merging the categories at most as favorable to it and hence define the odds (i.e. cumulative odds). Pairwise ratios of such odds (i.e. cumulative odds ratios) based on pairs of treatments are combined conveniently to derive a measure of relative superiority and hence the allocation probability functions. For practical implementation, we suggest response-adaptive randomization (RAR), that is, update the allocation probabilities dynamically using the available allocation and response information to favor the treatment doing better. Empirical as well as large sample properties following the randomization are investigated in detail. Moreover, a real clinical trial with trauma patients is redesigned using the proposed RAR to envisage practical applicability. © The Author(s) 2019.

Statistical Methods in Medical Research

A multi-treatment response adaptive design for ordinal categorical responses

In several areas of research, data collection in the usual sense may not be feasible or may not be required. Data&mdash;not the ones directly needed to study the underlying phenomenon&mdash;may be available in documents, artifacts, public pronouncements, images, newspaper reports or television serials and the like. Messages bearing on the research questions as are covertly contained in such data have to be deciphered, coded and then subjected to some form of analysis to draw relevant conclusions. This exercise is known as Content Analysis and has a great appeal to social scientists. Usually, more than one coder or referee or rater will be coding the data into some categories and agreement among the raters will be examined by using simple statistical tools. Once sufficient agreement among raters has been established, we proceed to test for relevant research hypotheses using statistical techniques appropriate to categorical data. The present chapter discusses several measures of concordance among raters applicable to different situations and provides their standard errors, so that observed values of the measures can be tested for their significance or otherwise. Several illustrations have been provided to facilitate application of techniques used in Content Analysis.

Statistical Methods in Social Science Research

Content Analysis

There are situations when we need information on sensitive features/characteristics of the individuals in a population. Usual sampling techniques based on &lsquo;direct&rsquo; questionnaire may not be fruitful and are likely to lead to &lsquo;refusal&rsquo; or &lsquo;untruthful&rsquo; reporting. To overcome such undesirable consequences, randomized response techniques [RRTs, in short] have been introduced and extensively used in real-life situations. We discuss some salient features of this technique.

Randomized Response Techniques

Meta-analysis is concerned with methods for combining evidences from seemingly different sources&mdash;but with the same goal. One simple example is derived from the context of measurement of pollution in a waterbody. Suppose several water samples have been randomly taken from the waterbody and sent to different laboratories for carrying out laboratory analyses.

Meta-Analysis

The article studies the log-logistic class of dose–response bioassay models in the binomial set-up. The dose is identified by the potency adjusted mixing proportions of two similar compounds. Models for both absence and presence of interaction between the compounds have been considered. The aim is to investigate the D- and Ds-optimal mixture designs for the estimation of the full set of parameters or for the estimation of potency for a best guess of the parameter values. We also indicate how to find the optimal design to estimate the mixing proportions at which the probability of success attains a given value in the absence of the interaction effect. © 2018 Taylor & Francis Group, LLC.

Communications in Statistics: Simulation and Computation

Optimum mixture designs for the log-logistic doseâ€“response model with mixture of two similar compounds

This book presents various recently developed and traditional statistical techniques, which are increasingly being applied in social science research. The social sciences cover diverse phenomena arising in society, the economy and the environment, some of which are too complex to allow concrete statements; some cannot be defined by direct observations or measurements; some are culture- (or region-) specific, while others are generic and common. Statistics, being a scientific method – as distinct from a ‘science’ related to any one type of phenomena – is used to make inductive inferences regarding various phenomena. The book addresses both qualitative and quantitative research (a combination of which is essential in social science research) and offers valuable supplementary reading at an advanced level for researchers.

Physiology

Statistics and its Applications

With reference to “point estimation” of a real-valued parameter Θ involved in the distribution of a real-valued random variable X, we consider a sample size n and an underlying unbiased estimator (Formula presented.) of Θ for every n = k, k + 1, k + 2, . . . ; where k is the minimum sample size needed for existence of unbiased estimator(s) of Θ based on (X1, X2, .... Xk).. We wish to investigate exact small-sample properties of the sequence of estimators considered here. This we study by considering what is termed “coverage probability” (CP) and defined as (Formula presented.). For Θ &gt; 0, we may redefine CP(n,c) as (Formula presented.) since (Formula presented.). When Θ &gt; 0 serves as a scale parameter, bounds to the ratio are more meaningful than bounds to the difference. In either case, it is desired that the sequence CP(n, c) n = k, k + 1, k + 2, ......] behaves like an increasing sequence for every c &gt; 0. We may note in passing that we are asking for a property beyond “consistency” of a sequence of unbiased estimators. As is well known, consistency is a large-sample property. In this article we discuss several interesting features of the behavior of the CP(n,c) in the exact sense. © 2018 Grace Scientific Publishing, LLC.