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20192
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Subject: Mathematics × Author: Manpreet Kaur × Start date: 2005 ×
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    Improved randomised response technique for estimation of sensitive character
    (Punjab Agricultural University, Ludhiana, 2019) Manpreet Kaur; Grewal, Inderjit Singh
    Getting correct answers to sensitive questions from the respondents and estimating the population parameters on variables that are sensitive in nature is still a problem in survey sampling. In the present project work, problem of estimation of population proportion of sensitive characteristic have been studied. For this improved randomized response device has been developed by taking the two cases of unrelated question, case-I „when the unrelated characteristic is known‟ and other case-II „when the unrelated characteristic is not known‟. Two estimators have been proposed one for known value of and other for unknown value of which were found to be unbiased. The expression for variances and unbiased estimates for the variances of the proposed estimators have been obtained. The optimum value of sample sizes have been worked out for which the minimum variance for the proposed estimators have also been obtained. In order to see relative efficiency, the proposed estimators have been compared on the basis of relative efficiency with respect to Tiwari and Mehta (2016) and Mangat (1992). An empirical study have been conducted and concluded graphically that proposed estimators are better than the estimators of Tiwari and Mehta (2016), Mangat (1992).
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    ThesisItemOpen Access
    Gardner solitons in Electron-Positron-Ion plasma featuring Cairns-Tsallis electrons
    (Punjab Agricultural University, Ludhiana, 2019) Manpreet Kaur; Parveen Bala
    Solitary waves are nonlinear and localized structures which arise when there is balance between nonlinearity and dispersion. In the present study, the effects of non-thermal and non-extensive distribution of electrons on the soliton propagation in plasma system containing Boltzmann positrons have been studied. The given distribution is applicable to this study to a limited range of values of q and α, 0.6< q≤ 1 and 0≤ α< 0.25. Using Reductive Perturbation method, Korteweg-de Vries (K-dV), modified K-dV (mK-dV) and Gardner equations are derived for electron-positron-ion (e-p-i) plasma system. The soliton solution of the Gardner equation is discussed in detail. Results have been interpreted in the form of graphs. It is found that for a given set of parameter values, there exists a critical value of q (i.e, qc) below which only rarefactive K-dV solitons exist and above it compressive K-dV solitons exist. However, at the critical value of q, both compressive and rarefactive mK-dV solitons co-exist. In this region, for q > qc, rarefactive Gardner solitons and for q < qc, compressive Gardner solitons are found. The present investigation may help us to understand the electrostatic perturbations in laboratory and space plasmas.