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A characterization of star-perfect graphs
Motivated by Berge perfect graphs, we define star-perfect graphs and characterize them. For a finite simple graph G(V, E), let (Formula presented.) denote the minimum number of induced stars contained in G such that the union of their vertex sets is V(G), and let (Formula presented.) denote the maximum number of vertices in G such that no two of them are contained in the same induced star of G. We call a graph G star-perfect if (Formula presented.), for every induced subgraph H of G. A graph G is star-perfect if and only if G is (Formula presented.) -free, for every (Formula presented.). A bipartite graph G is star-perfect if and only if every induced cycle in G is of length (Formula presented.). The minimum parameter (Formula presented.) and the maximum parameter (Formula presented.) have been extensively studied in various contexts. 2024 The Author(s). Published with license by Taylor & Francis Group, LLC. -
A Family of Mexican Hat Wavelet Stieltjes Transform for Unbounded Non-decreasing Functions
In the present article, we examine the characteristics of the Mexican hat wavelet Stieltjes transform (MHWST) for a specific set of functions belonging to one of the sub-class of bounded variation functions. The subset comprises functions that are unbounded and non-decreasing. Further, a unified approach is applied to establish a uniqueness theorem and subsequently derive a representation theorem for the MHWST. The Author(s), under exclusive licence to The National Academy of Sciences, India 2024. -
Impact of helpful reviews on customer purchase intention with special reference to mobile phone reviews
Technological advances in the digital space have provided renewed impetus to businesses. Costly, labor-intensive marketing campaigns have been replaced by digital marketing. However, along with benefits, the increasing sophistication and exponential growth of e-commerce businesses have also introduced new challenges. The large number of similar product offerings and the high volume of reviews have created a technology-induced hurdle for consumers that can impair their thought processes. Often, users will only scan the top few reviews to arrive at a decision. In the current setup, older reviews that accumulate votes over time are found at the top of the helpful review list, in contrast to fresh entrants. The current study proposes placing reviews in appropriate positions in the helpful review list using statistical and scientifically derived helpfulness scores. The study utilized a sample of consumer goods (specifically, mobile phones) and re-ranked reviews based on their expected score. Amazon.in provided the initial review dataset. Random Forest and gradient-boosting regression techniques were used to predict review helpfulness. An Elaboration Likelihood Model was used to explore the impact of central and peripheral cues on review helpfulness. The gradient-boosting regression was the best-performing method of predicting review helpfulness, and the reviews were re-ranked. The re-ranked reviews were tested for helpfulness vis-a-vis the initial ranking of reviews using the survey method. The result indicated that the proposed re-ranking of reviews was more helpful to end users and helped mitigate uncertainty in decisions. The study utilized the Information Acceptance Model to assess the influence of electronic word of mouth on purchase intention. 2023 Conscientia Beam. All Rights Reserved. -
A Meta-Analysis on the Determinants of Online Product Reviews with Moderating Effect of Product Type
The technological advances in digital space have provided a renewed impetus for business to expand their footprint across digital modes. The growth of the internet and the ease of its access to the masses has encouraged many businesses to go online. Online e-commerce platforms make it easy to search, locate and place orders. Technology-assisted supply chains and fast delivery mechanisms ensure that users don't have to go elsewhere to fulfill their needs. To earn loyalty and customer satisfaction, e-commerce platforms have evolved into a sophisticated recommender system. It has evolved from just an informational source to a participative mode where users can share their experiences about their purchases. Customer values other user experiences more than the information provided by the seller. The presence of many conflicting and contradicting reviews can make the task of making rational decisions difficult for many users. Many studies were performed to understand what constitutes a review helpful and came up with different or mixed outcomes. The present study reviews the factors that influence online customer reviews helpful. Meta-analysis was performed to reconcile the mixed findings of different factors of online review helpfulness. The meta-analysis found that with the moderating effect of product type, factors like review length, readability, rating, reputation, and expertise positively correlate with helpfulness. Further, the customer finds moderate reviews more helpful in terms of polarity. Meta-analysis has a mix of findings for the selected data points in the study. The mixed findings include product type (search, experience, or other) and helpfulness measurement criteria. 2022 Kavita Rawat and Sunita Kumar. This is an open access article licensed under the Creative Commons Attribution-NonCommercial 4.0 International License. -
Fragile pillars of food security: exploring the challenges of availability, accessibility, and quality for global food regime; [Pilares freis da seguran alimentar: explorao dos desafios de disponibilidade, acessibilidade e qualidade para o regime alimentar global]
Hunger is a critical issue impacting a greater part of the world. Food distribution systems are failing millions of people, thereby leading to the crisis of food security. Various international declarations, like the UDHR and the ICESCR, have designated food and basic nutrition as integral elements of human rights. Therefore, provision for adequate and affordable food to all has become the dominant value for relevant regulatory and policy regimes. The problem is particularly sensitive to war-like events as is revealed by troubling statistics emerging against the backdrop of Covid-19, Russia-Ukraine War, and Israel-Hamas crisis. All these recent events have increased global food security concerns. This paper evaluates the fragile nature of food security in its multidisciplinary dimension. The methodology undertaken is a combination of quantitative and qualitative analytical mechanisms to explore the multidimensional issues of food insecurity. A systematic approach has been taken to identify food availability, food accessibility, food utilization, and environmental vulnerability as the intrinsic obstacles to any regulatory intervention. In this context, the paper analyses challenges to food accessibility as the core problem of right to food and food sovereignty regimes. It signifies the connection between the structural notion of accessibility and the legal concept of right to food through food sovereignty. It analyses the causal linkages between the problem of food security and other fundamental policy challenges, like poverty, unemployment, and social inequality. The international nature of the crisis is also manifested in the classic developed-developing nations divide. It, consequently, highlights the structural inefficiencies of the powerful international bodies, like the WTO, the World Bank, and the IMF. The comprehensive nature of the problem is explored through the idea of food sovereignty, which signifies the cultural sensitivity of food and nutrition. Food insecurity is not merely a productivity problem. The paper, therefore, suggests a consumer-centric model of food distribution and accessibility as an optimal and practical model for public policy and regulations. 2024 Centro Universitario de Brasilia. All rights reserved. -
Exploring the various methodologies of auditing the variables in a food supply chain and suggesting integrated audit framework
In recent years, the food supply chain has faced huge uncertainties, which has led to increasing interest in effective supply chain management in the industry. By considering the five key system inputs (purchasing, receiving, storing, processing, distributing) that are indispensable in the supply chain, the company can first take action to stabilize the supply chain performance, and secondly to improve its effectiveness by reducing uncertainty in the supply chain and operational capabilities. This paper outlines the key drivers and uncertainties in the food supply chain and describes a structured supply chain audit that can be used to measure the effectiveness of the supply chain. The purpose of this paper is to study the existing audit framework and regulations for food safety in the food supply chain and examine the flaws in the existing framework and build a consolidated single framework that incorporates the best practices and fills the gap of the existing audit frameworks for food security. 2020, Institute of Advanced Scientific Research, Inc.. All rights reserved. -
Exploring White Knight Syndrome in an Indian Setting: A Grounded Theory Approach
White knights are individuals who enter into romantic relationships with damaged and vulnerable partners, hoping that love will transform their partners behaviour or life. Existing literature on white knight is limited to a handful of studies, primarily based on Western population. The present research aimed at developing a substantive theory on white knight syndrome in an Indian setting. The study follows a qualitative paradigm and the research design is grounded theory approach to be specific. Participants for the study were screened using Lamias white knight checklist. Data has been collected from eighteen young adults aged 1825years through semi-structured interviews. The data was analyzed using Strauss and Corbin grounded theory analysis. The study identified six phasespre-relationship phase, needs exploration phase, shining white knight phase, drained white knight phase, golden realization phase, and finally delayed breakup. Along with the phases, the study identified factors, characteristics, and types of white knight. The study has implications in the clinical and counselling field in identifying and understanding white knight tendencies. Additionally, the theory is applicable in the Indian setting highlighting the intricate interaction between culture, norms, roles, and the recent social factors. 2023, The Author(s), under exclusive licence to Springer Nature Switzerland AG. -
Hubble Space Telescope Captures UGC 12591: Bulge/disc properties, star formation and 'missing baryons' census in a very massive and fast-spinning hybrid galaxy
We present Hubble Space Telescope ( HST ) observations of the nearby, massive, highly rotating hybrid galaxy UGC 12591, along with observations in the UV to FIR bands. HST data in V , I , and H bands is used to disentangle the structural components. Surface photometry shows a dominance of the bulge o v er the disc with an H-band B / D ratio of 69 per cent . The spectral energy distribution (SED) fitting reveals an extremely low global star formation rate (SFR) of 0 . 1-0 . 2 M yr-1 , exceptionally low for the galaxy's huge stellar mass of 1 . 6 0 11 M, implying a strong quenching of its SFR with a star formation efficiency of 3-5 per cent. For at least the past 10 8 yr, the galaxy has remained in a quiescent state as a sterile, 'red and dead' galaxy. UGC 12591 hosts a supermassive black hole (SMBH) of 6 . 18 0 8 M, which is possibly quiescent at present, i.e. we neither see large (1kpc) radio jets nor the SMBH contributing significantly to the mid-IR SED, ruling out strong radiative feedback of AGN. We obtained a detailed census of all observable baryons with a total mass of 6 . 46 0 11 M within the virial radius, amounting to a baryonic deficiency of 85 per cent relative to the cosmological mean. Only a small fraction of these baryons reside in a warm/hot circumgalactic X-ray halo, while the majority are still unobservable. We discussed various astrophysical scenarios to explain its unusual properties. Our work is a major step forward in understanding the assembly history of such e xtremely massiv e, isolated galaxies. 2022 The Author(s) Published by Oxford University Press on behalf of Royal Astronomical Society. -
Probing star formation in five of the most massive spiral galaxies observed through ASTROSAT UltraViolet Imaging Telescope
We present highly resolved and sensitive imaging of the five nearby massive spiral galaxies (with rotation velocities > 300 km s?1) observed by the UltraViolet Imaging Telescope onboard Indias multiwavelength astronomy satellite ASTROSAT, along with other archival observations. These massive spirals show a far-ultraviolet star formation rate in the range of ? 1.4 13.7 M? yr?1 and fall in the Green Valley region with a specific star formation rate within ? 10?11.5 10?10.5 yr?1. Moreover, the mean star formation rate density of the highly resolved star-forming clumps of these objects is in the range 0.011 0.098 M? yr?1 kpc?2, signifying localized star formation. From the spectral energy distributions, under the assumption of a delayed star formation model, we show that the star formation of these objects had peaked in the period of ? 0.8 2.8 Gyr after the Big Bang and the object that has experienced the peak sooner after the Big Bang show relatively less star-forming activity at z ? 0 and falls below the main-sequence relation for a stellar content of ? 1011 M?. We also show that these objects accumulated much of their stellar mass in the early period of evolution with ? 31 42 per cent of the total stellar mass obtained in a time of (1/16) (1/5)th the age of the Universe. We estimate that these massive objects convert their halo baryons into stars with efficiencies falling between ? 7 and 31 per cent. 2024 Oxford University Press. All rights reserved. -
Studies on photophysical properties of mono-carbonyl curcumin analogues: Experimental andtheoretical approach
The solvatochromic fluorescence behaviour of mono-carbonyl curcumin analogues has been studied in ten different solvents ranging from non-polar to polar. The solvent effect on the spectral properties of analogues has been discussed. The ground state dipole moments were estimated experimentally by Bilot-Kawski equation which is a function of Stokes shift with the solvent polarity parameters and Guggenheim method and theoretically by TD-DFT studies. The excited state dipole moment was determined using Bilot-Kawski equations. The excited state dipole moments for the two molecules were found to be higher than their corresponding ground state dipole moments. Theoretically Frontier molecular orbital (HOMO/ LUMO) energies were determined by Gaussian 09 W software using TD-DFT. 2018 Oriental Scientific Publishing Company. All rights reserved. -
Multiple slip effects on MHD non-Newtonian nanofluid flow over a nonlinear permeable elongated sheet: Numerical and statistical analysis
Purpose: The purpose of this paper is to examine the interaction effects of a transverse magnetic field and slip effects of Casson fluid with suspended nanoparticles over a nonlinear stretching surface. Mathematical modeling for the law of conservation of mass, momentum, heat and concentration of nanoparticles is executed. Design/methodology/approach: Governing nonlinear partial differential equations are reduced into nonlinear ordinary differential equations and then shooting method is employed for its solution. The slope of the linear regression line of the data points is calculated to measure the rate of increase/decrease in the reduced Nusselt number. Findings: The effects of magnetic parameter (0=M=4), Casson parameter (0.1=?<8), nonlinear stretching parameter (0=n=3) and porosity parameter (0=P=6) on axial velocity are shown graphically. Numerical results were compared with another numerical approach and an excellent agreement was observed. This study reveals the fact that the Brownian motion parameter and boundary layer thickness have a direct relationship with temperature. Also, Brownian motion and thermophoresis contribute to an increase in the thermal boundary layer thickness. Originality/value: Despite the immense significance and repeated employment of non-Newtonian fluids in industry and science, no attempt has been made up till now to inspect the Casson nanofluid flow with a permeable nonlinear stretching surface. 2019, Emerald Publishing Limited. -
Magnetohydrodynamic flow of nano Williamson fluid generated by stretching plate with multiple slips
Purpose: The purpose of this paper is to present an exploration of multiple slips and temperature dependent thermal conductivity effects on the flow of nano Williamson fluid over a slendering stretching plate in the presence of Joule and viscous heating aspects. The effectiveness of nanoparticles is deliberated by considering Brownian moment and thermophoresis slip mechanisms. The effects of magnetism and radiative heat are also deployed. Design/methodology/approach: The governing partial differential equations are non-dimensionalized and reduced to multi-degree ordinary differential equations via suitable similarity variables. The subsequent non-linear problem treated for numerical results. To measure the amount of increase/decrease in skin friction coefficient, Nusselt number and Sherwood number, the slope of linear regression line through the data points are calculated. Statistical approach is implemented to analyze the heat transfer rate. Findings: The results show that temperature distribution across the flow decreases with thermal conductivity parameter. The maximum friction factor is ascertained at stronger magnetic field. Originality/value: In the current paper, the magneto-nano Williamson fluid flow inspired by a stretching sheet of variable thickness is examined numerically. The rationale of the present study is to generalize the studies of Mebarek-Oudina and Makinde (2018) and Williamson (1929). 2019, Emerald Publishing Limited. -
Fixed points in n-gonal graphical b-metric spaces under contractive conditions
In this paper, we will define a new metric space called n-gonal graphical b-metric space. We will also prove some fixed point theorems in said metric space and give suitable examples to illustrate our results. These results will help to solve many nonlinear convex models in machine learning and optimization by formulating them in fixed point schemes of optimization. Our paper opens the door for researchers to work in the intersecting area of machine learning and functional analysis in the frame work of n-gonal graphical b-metric space. 2023 World Scientific Publishing Company. -
MONG: An extension to galaxy clusters
The presence of dark matter (DM), though well established by indirect evidence, is yet to be observed directly. Various DM detection experiments running for several years have yielded no positive results. In view of these negative results, we had earlier proposed alternate models by postulating a minimum gravitational field strength (minimum curvature) and a minimum acceleration. These postulates led to the modified Newtonian dynamics and modified Newtonian gravity (MONG). The observed flat rotation curves of galaxies were also accounted for through these postulates. Here, we extend these postulates to galaxy clusters and model the dynamical velocity-distance curve for a typical cluster such as the Virgo cluster. The radial velocities of galaxies in the Virgo cluster are also obtained through this model. Observations show an inconsistency in the Hubble flow at a mean cluster distance of 17 Mpc, which is expected in regions of high matter density. This decrease in velocity is predicted by our model of modified gravity (MONG). The radial velocity versus distance relation for galaxies in the Virgo cluster obtained using MONG is in agreement with observations. 2022 World Scientific Publishing Company. -
Can Hubble tension be eased by invoking a finite range for gravity?
The estimation of the Hubble constant in the past few decades has increasingly become more accurate with the advancement of new techniques. However, its value seems to depend on the epoch at which the measurements are made. The Planck estimate of the Hubble constant from the observations of the cosmic microwave background radiation in the early universe is about 67km\s\Mpc, whereas that obtained from the distance indicators at the current epoch is ?73-74km\s\Mpc. This discrepancy between the two groups of measurement is termed as the Hubble tension which has gained much attention in the past few decades with growing significance as measurements from both, the early and the late universe, studies continue to produce results with increasing precision. In this work, we propose a modification to gravity by considering a finite range gravitational field as an alternate explanation for this discrepancy in the value of the Hubble constant. 2024 World Scientific Publishing Company. -
Has Indias Employment Guarantee Program Achieved Intended Targets?
This paper explores the performance of the worlds largest employment guarantee program, the Mahatma Gandhi National Rural Employment Guarantee Schemes in India, both nationally and through a sub-national-level comparison based on key performance indicators viz. (i) financial indicators, (ii) physical performance indicators, and (iii) inclusiveness indicators. The paper is based on administrative data taken from the Ministry of Rural Development from 2006 to 2019. Despite sharp increases in fund allocation, total expenditures, and utilization rates, there was deceleration in majority of physical performance indicators after 2016, including total person-days employment and person-days of employment per household, with wide variation in sub-national level implementation capabilities. The finding also rejects the falsity of saturation of MGNREGA work in the rural areas, which is reflected in a strong positive correlation between fund allocation and employment generation. Its broader objective of social safety net for vulnerable people in rural areas shows an achievement, although with some gaps in implementation. JEL classification: H53, J43, P25 The Author(s) 2021. -
Optical and Electrochromic Properties of CeO2/WO3 Hybrid Thin Films Prepared by Hydrothermal and Sputtering
Innovative chromogenic nanostructures like hybrids but also composite materials can be increased electrochromic efficiency because of their prospective application values in low-power displays, smart windows, electronic papers, and car anti-reflect mirrors. We used a hydrothermal approach to make Cerium oxide Nanorods have various ratios in this report. DC magnetron sputtering procedures cover the generated cerium oxide nanorods of various diameters with a tungsten oxide layer in one step. the surface plasmon effect varies depending on the size of Ce Nanorods, and this phenomenon impacts electrochromic results. the electrochromic performances of CeO2/WO3 nanorods on FTO-coated glass slides are examined using a 0.5 M solution of H2SO4 as the electrolyte in the visible range. These structures produce considerable optical modulation (47 %, 45 %, and 41 % at 700 nm) and coloration efficiency (11.6, 7.57, and 10.84 cm2C-1 at 700 nm). 2022 Seventh Sense Research Group -
DROUGHT MITIGATION THROUGH HYDROGEL APPLICATION IN RICE (Oryza sativa L.) CULTIVATION
Sustainability in irrigation is an essential step towards responsible water consumption. In recent years, many studies have sketched climate-resilient agricultural practices to fight drought and uncertain rainfall patterns. Major rain-fed crops such as paddy and wheat require aid when there are abnormal dry spells. To mitigate the loss of crops from such events, superabsorbent polymers can be used. Soils amended with hydrogel or Superabsorbent polymer (SAP) retain moisture during drought to prevent loss of water through evaporation and percolation. This allows the crop to grow with less shock from drought. This study compares rice (Oryza sativa L.) growth rate under application (treatment groups) and non-application (control groups) of hydrogel, considering their high-water requirement. NDLR07 (recently developed) and BPT5204 (local variety) rice varieties were chosen for the current study. Randomized controlled trials were performed for each variety on a control group (NC & BC) and 3 treatment groups with 20% (NT20 & BT20), 40% (NT40 & BT40), and 60% (NT60 & BT60) deficit water supplies respectively. N, T, C refers to seed type, treatment group, control group respectively. Intermittent drought condition was imposed for 14 days to assess the resilience of crops. The water retention capacity of the sandy loam soil was better for treatment groups by 20% than control groups even at an average temperature of 40 ?. Treatment groups continued growing through the drought phase and after, while control groups showed stagnation. Among the tested treatment groups, NT20 had the highest growth among all trials. The results of the study suggested that hydrogel application can help to combat droughts and thereby contribute to sustainable agricultural production by restricting the involvement of climate changes. 2021, Editorial board of Journal of Experimental Biology and Agricultural Sciences. All rights reserved. -
Effect of post annealing on DC magnetron sputtered tungsten oxide (WO3) thin films for smartwindow applications
Tungsten oxide (WO3) thin films were deposited on Fluorine Doped Tin Oxide (FTO) and Corning Glass (CG) glass substrate by DC magnetron sputtering. The annealing temperature was varied to study its effect on surface morphology, structural, electrochromic (EC), and optical properties and these are investigated by Scanning Electron Microscope (SEM), X-ray Diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, Cyclic voltammetry, and ultraviolet (UV) spectroscopy. From SEM analysis WO3 thin films annealed at 27 C, 100 C, 200 C, and 300 C were shown to crack free after that cracked film was observed for 400 C. From the XRD investigation that the WO3 thin films annealed at 27 C, 100 C, 200 C, and 300 C were amorphous and crystallized at 400 C. The optical band gap (Eg) of WO3 films was decreased from 2.98 eV to 2.30 eV with an increase in annealed temperature. The coloration efficiency (CE) was observed at 51.26 cm2/C at 300 C and 35.06 cm2/C at 400 C and the lowest diffusion coefficient was observed at 5.86 10?10 cm2/s at 400 C. On coloring efficiency, which can be very important in electrochromic (EC) applications, post-annealing has been seen to have a strong influence. 2023 Elsevier B.V. -
Evaluation of relation of personality, parenting, stress and depression in patients with secondary amenorrhoea
Background: Relatively few studies have assessed psychosocial correlates for secondary amenorrhea. Our study of the Gynaecological condition concerning personality factor (on introversion-extroversion dimension), parenting (authoritarian and authoritative) style, depression and perceived stress addresses this gap in the literature. The study inquires, whether these variables are related. Aims and objectives: To evaluate the relation of personality, parenting, stress and depression in patients with secondary amenorrhoea. Methods: Evaluation was done for forty-four young-adult female patients (with their fathers alive) affected by secondary amenorrhea, requesting help for menstrual disorders. The Parental Authority Questionnaire administered on the parent of patients, and Beck Depression Inventory, Perceived stress scale, Kundu Introversion-Extraversion Inventory on patients. In addition to that sixty healthy participants were recruited. The 104 participants were divided into two groups according to the presence (44 cases) or the absence (60 cases) of clinically diagnosed secondary amenorrhea. Results: Appropriate use of correlation coefficient followed by a test of significance revealed significant correlations between the variables which were hypothesised in accordance and hadbeen discussedregarding future research. Conclusions: Secondary amenorrhea was found to be possibly associated with personality factors, stress, depression and the kind of parenting individuals receive during their lifetime.