93 research outputs found
A Nonparametric Ensemble Binary Classifier and its Statistical Properties
In this work, we propose an ensemble of classification trees (CT) and
artificial neural networks (ANN). Several statistical properties including
universal consistency and upper bound of an important parameter of the proposed
classifier are shown. Numerical evidence is also provided using various real
life data sets to assess the performance of the model. Our proposed
nonparametric ensemble classifier doesn't suffer from the `curse of
dimensionality' and can be used in a wide variety of feature selection cum
classification problems. Performance of the proposed model is quite better when
compared to many other state-of-the-art models used for similar situations
A novel distribution-free hybrid regression model for manufacturing process efficiency improvement
This work is motivated by a particular problem of a modern paper
manufacturing industry, in which maximum efficiency of the fiber-filler
recovery process is desired. A lot of unwanted materials along with valuable
fibers and fillers come out as a by-product of the paper manufacturing process
and mostly goes as waste. The job of an efficient Krofta supracell is to
separate the unwanted materials from the valuable ones so that fibers and
fillers can be collected from the waste materials and reused in the
manufacturing process. The efficiency of Krofta depends on several crucial
process parameters and monitoring them is a difficult proposition. To solve
this problem, we propose a novel hybridization of regression trees (RT) and
artificial neural networks (ANN), hybrid RT-ANN model, to solve the problem of
low recovery percentage of the supracell. This model is used to achieve the
goal of improving supracell efficiency, viz., gain in percentage recovery. In
addition, theoretical results for the universal consistency of the proposed
model are given with the optimal value of a vital model parameter. Experimental
findings show that the proposed hybrid RT-ANN model achieves higher accuracy in
predicting Krofta recovery percentage than other conventional regression models
for solving the Krofta efficiency problem. This work will help the paper
manufacturing company to become environmentally friendly with minimal
ecological damage and improved waste recovery
Bayesian Neural Tree Models for Nonparametric Regression
Frequentist and Bayesian methods differ in many aspects, but share some basic
optimal properties. In real-life classification and regression problems,
situations exist in which a model based on one of the methods is preferable
based on some subjective criterion. Nonparametric classification and regression
techniques, such as decision trees and neural networks, have frequentist
(classification and regression trees (CART) and artificial neural networks) as
well as Bayesian (Bayesian CART and Bayesian neural networks) approaches to
learning from data. In this work, we present two hybrid models combining the
Bayesian and frequentist versions of CART and neural networks, which we call
the Bayesian neural tree (BNT) models. Both models exploit the architecture of
decision trees and have lesser number of parameters to tune than advanced
neural networks. Such models can simultaneously perform feature selection and
prediction, are highly flexible, and generalize well in settings with a limited
number of training observations. We study the consistency of the proposed
models, and derive the optimal value of an important model parameter. We also
provide illustrative examples using a wide variety of real-life regression data
sets
On the role of pressure anisotropy for relativistic stars admitting conformal motion
We investigate the spacetime of anisotropic stars admitting conformal motion.
The Einstein field equations are solved using different ansatz of the surface
tension. In this investigation, we study two cases in details with the
anisotropy as: [1] [2] where, n, and are arbitrary constants.
The solutions yield expressions of the physical quantities like pressure
gradients and the mass.Comment: 21 pages, accepted for publication in 'Astrophysics and Space
Science
Assessing Smell Alteration as Clinical Feature of COVID-19: A Descriptive Study in a Rural Based Tertiary Care COVID Hospital
Introduction
COVID-19 is an ongoing viral pandemic and a very contagious disease. Other than common symptoms like fever, cough and malaise; alteration in smell and taste perception may be the presenting symptoms in a significant number of patients infected with COVID-19.
Materials and Methods
Presence of smell alteration assessed among 150 mild to moderate COVID-19 positive patients admitted at our COVID hospital as well as 150 COVID-19 negative patients in May-June, 2021. Use and throw smell cards were used to detect smell alteration for all. Symptom onset and its resolution were noted. Smell alteration was also evaluated in different age group and gender.
Results
81 (54%) patients among 150 COVID positive cases had smell alteration compared to 9 (6%) patients among non-COVID arm (p value <0.0001). Overall smell alteration was more prevalent among male COVID patients. Hyposmia is more prevalent among younger age group compared to anosmia, which is more among older side. Olfactory dysfunction is seen to be developed at presentation or within 5 days from starting of infection with other symptoms. More than 90% patients regained smell perception within two months post infection.
Conclusion
54% COVID positive patients reported smell loss either at presentation or within 5 days of infection. Using smell cards for smell assessment and being cautious about smell alteration as early symptom helps us to diagnose COVID-19 early
Synthesis, X-ray structure and in vitro cytotoxicity studies of Cu(I/II) complexes of thiosemicarbazone: special emphasis on their interactions with DNA
4-(p-X-phenyl)thiosemicarbazone of napthaldehyde {where X = Cl (HL¹) and X = Br (HL²)}, thiosemicarbazone of quinoline-2-carbaldehyde (HL³) and 4-(p-fluorophenyl)thiosemicarbazone of salicylaldehyde (H₂L⁴) and their copper(I) {[Cu(HL¹)(PPh₃)₂Br]·CH₃CN (1) and [Cu(HL²)(PPh₃)₂Cl]·DMSO (2)} and copper(II) {[(Cu₂L³₂Cl)₂(μ-Cl)₂]·2H₂O (3) and [Cu(L⁴)(Py)] (4)} complexes are reported herein. The synthesized ligands and their copper complexes were successfully characterized by elemental analysis, cyclic voltammetry, NMR, ESI-MS, IR and UV-Vis spectroscopy. Molecular structures of all the Cu(I) and Cu(II) complexes have been determined by X-ray crystallography. All the complexes (1–4) were tested for their ability to exhibit DNA-binding and -cleavage activity. The complexes effectively interact with CT-DNA possibly by groove binding mode, with binding constants ranging from 10⁴ to 10⁵ M⁻¹. Among the complexes, 3 shows the highest chemical (60%) as well as photo-induced (80%) DNA cleavage activity against pUC19 DNA. Finally, the in vitro antiproliferative activity of all the complexes was assayed against the HeLa cell line. Some of the complexes have proved to be as active as the clinical referred drugs, and the greater potency of 3 may be correlated with its aqueous solubility and the presence of the quinonoidal group in the thiosemicarbazone ligand coordinated to the metal
"The fruits of independence": Satyajit Ray, Indian nationhood and the spectre of empire
Challenging the longstanding consensus that Satyajit Ray's work is largely free of ideological concerns and notable only for its humanistic richness, this article shows with reference to representations of British colonialism and Indian nationhood that Ray's films and stories are marked deeply and consistently by a distinctively Bengali variety of liberalism. Drawn from an ongoing biographical project, it commences with an overview of the nationalist milieu in which Ray grew up and emphasizes the preoccupation with colonialism and nationalism that marked his earliest unfilmed scripts. It then shows with case studies of Kanchanjangha (1962), Charulata (1964), First Class Kamra (First-Class Compartment, 1981), Pratidwandi (The Adversary, 1970), Shatranj ke Khilari (The Chess Players, 1977), Agantuk (The Stranger, 1991) and Robertsoner Ruby (Robertson's Ruby, 1992) how Ray's mature work continued to combine a strongly anti-colonial viewpoint with a shifting perspective on Indian nationhood and an unequivocal commitment to cultural cosmopolitanism. Analysing how Ray articulated his ideological positions through the quintessentially liberal device of complexly staged debates that were apparently free, but in fact closed by the scenarist/director on ideologically specific notes, this article concludes that Ray's reputation as an all-forgiving, ‘everybody-has-his-reasons’ humanist is based on simplistic or even tendentious readings of his work
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