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1 – 10 of over 3000Nilankush Acharya, Kalidas Das and Prabir Kumar Kundu
The purpose of this paper is to focus on the influence of multiple slips on MHD Williamson nanofluid flow embedded in porous medium towards a linearly stretching sheet that has…
Abstract
Purpose
The purpose of this paper is to focus on the influence of multiple slips on MHD Williamson nanofluid flow embedded in porous medium towards a linearly stretching sheet that has been investigated numerically. The whole analysis has been carried out considering the presence of nth-order chemical reaction between base fluid and nanoparticles.
Design/methodology/approach
A similarity transformation technique has been adopted to convert non-linear governing partial differential equations into ordinary ones and then they are solved by using both the RK-4 method and Laplace transform homotopy perturbation method. The consequences of multiple slip parameters on dimensionless velocity, temperature and concentration and heat and mass transfer rates have been demonstrated using tabular and graphical outline.
Findings
The investigation explores that the Nusselt number reduces for escalating behaviour of velocity slip and thermal slip parameter. Fluid’s temperature rises in the presence of generative reaction parameter.
Originality/value
A fine conformity of the current results has been achieved after comparing with previous literature studies. Considering destructive chemical reaction, reduced Nusselt number is found to decrease, but reverse consequence has been noticed in the case of generative chemical reaction. Mass transport diminishes when the order of chemical reaction amplifies for both destructive and generative reactions.
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We provide a new characterization of the equality of two positive-definite matrices A and B, and we use this to propose several new computationally convenient statistical tests…
Abstract
We provide a new characterization of the equality of two positive-definite matrices A and B, and we use this to propose several new computationally convenient statistical tests for the equality of two unknown positive-definite matrices. Our primary focus is on testing the information matrix equality (e.g. White, 1982, 1994). We characterize the asymptotic behavior of our new trace-determinant information matrix test statistics under the null and the alternative and investigate their finite-sample performance for a variety of models: linear regression, exponential duration, probit, and Tobit. The parametric bootstrap suggested by Horowitz (1994) delivers critical values that provide admirable level behavior, even in samples as small as n = 50. Our new tests often have better power than the parametric-bootstrap version of the traditional IMT; when they do not, they nevertheless perform respectably.
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Jawad Ahmad Dar, Kamal Kr Srivastava and Sajaad Ahmad Lone
The Covid-19 prediction process is more indispensable to handle the spread and death occurred rate because of Covid-19. However early and precise prediction of Covid-19 is more…
Abstract
Purpose
The Covid-19 prediction process is more indispensable to handle the spread and death occurred rate because of Covid-19. However early and precise prediction of Covid-19 is more difficult because of different sizes and resolutions of input image. Thus these challenges and problems experienced by traditional Covid-19 detection methods are considered as major motivation to develop JHBO-based DNFN.
Design/methodology/approach
The major contribution of this research is to design an effectual Covid-19 detection model using devised JHBO-based DNFN. Here, the audio signal is considered as input for detecting Covid-19. The Gaussian filter is applied to input signal for removing the noises and then feature extraction is performed. The substantial features, like spectral roll-off, spectral bandwidth, Mel-frequency cepstral coefficients (MFCC), spectral flatness, zero crossing rate, spectral centroid, mean square energy and spectral contract are extracted for further processing. Finally, DNFN is applied for detecting Covid-19 and the deep leaning model is trained by designed JHBO algorithm. Accordingly, the developed JHBO method is newly designed by incorporating Honey Badger optimization Algorithm (HBA) and Jaya algorithm.
Findings
The performance of proposed hybrid optimization-based deep learning algorithm is estimated by means of two performance metrics, namely testing accuracy, sensitivity and specificity of 0.9176, 0.9218 and 0.9219.
Research limitations/implications
The JHBO-based DNFN approach is developed for Covid-19 detection. The developed approach can be extended by including other hybrid optimization algorithms as well as other features can be extracted for further improving the detection performance.
Practical implications
The proposed Covid-19 detection method is useful in various applications, like medical and so on.
Originality/value
Developed JHBO-enabled DNFN for Covid-19 detection: An effective Covid-19 detection technique is introduced based on hybrid optimization–driven deep learning model. The DNFN is used for detecting Covid-19, which classifies the feature vector as Covid-19 or non-Covid-19. Moreover, the DNFN is trained by devised JHBO approach, which is introduced by combining HBA and Jaya algorithm.
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Wooje Cho, Woojung Chang and Dongryul Lee
In responding to competitors' strategic choices, firms must choose whether to allocate their customer relationship management (CRM) resources primarily to retaining existing…
Abstract
Purpose
In responding to competitors' strategic choices, firms must choose whether to allocate their customer relationship management (CRM) resources primarily to retaining existing customers or to acquiring new customers. To address this critical but understudied question, the authors examine the strategic choices of two competing firms between retention- and acquisition-focused strategies in consideration of switching costs, technological advancement level, and market share.
Design/methodology/approach
The authors develop and analyze a game-theoretic model to investigate the strategic choices of two competing firms between retention- and acquisition-focused strategies.
Findings
When switching costs are high, findings show that when the degree of technological advancement is high (low), both firms should employ acquisition-focused (retention-focused) strategies to maximize their profits. When switching costs are low and there are a low degree of technological advancement and asymmetric market shares, the firms choose retention-focused strategies in equilibrium, but only the firm with the higher market share can maximize its profit. When switching costs are low, technological advancement levels are high, and the market shares are asymmetric, the firm with the higher market share chooses a retention-focused CRM strategy, while the rival with lower market share adopts an acquisition-focused strategy in equilibrium. However, neither firm can maximize its profits.
Originality/value
Prior research focused on a single firm's price discrimination decision without considering a competitor's strategic choice. To address this research gap, the authors examine where firms should assign their CRM resources (retention vs. acquisition) in response to a competitor's CRM strategy. This study provides guidance for optimal decision-making regarding a firm's CRM resource allocation in a duopoly market.
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M.A.I. El‐Shaarawi and S.A. Haider
Conjugate laminar forced convection heat transfer in the entry region of eccentric annuli is numerically investigated. Heat transfer parameters are presented for a fluid of Pr …
Abstract
Conjugate laminar forced convection heat transfer in the entry region of eccentric annuli is numerically investigated. Heat transfer parameters are presented for a fluid of Pr = 0.7 flowing in an annulus of radius ratio 0.5 for four values of dimensionless eccentricity ranging from 0.1 to 0.7. Solid‐fluid conductivity ratio (KR) is varied to cover the range for practical cases with commonly encountered inner and outer tube thickness. Boundary conditions applied are isothermal heating of the inner surface of the core tube, while the outer surface of the external tube is maintained at the inlet fluid temperature. Limits for KR above which the conjugation can be neglected are obtained.
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Discusses the 6th ITCRR, its breadth of textile and clothing research activity, plus the encouragement given to workers in this field and its related areas. States that, within…
Abstract
Discusses the 6th ITCRR, its breadth of textile and clothing research activity, plus the encouragement given to workers in this field and its related areas. States that, within the newer research areas under the microscope of the community involved, technical textiles focuses on new, ‘smart’ garments and the initiatives in this field in both the UK and the international community at large. Covers this subject at length.
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The objective of this study is to present a successful strategy to promote Korea as the logistics hub of Northeast Asia. Firstly, we introduce the necessity of a logistic hub…
Abstract
The objective of this study is to present a successful strategy to promote Korea as the logistics hub of Northeast Asia. Firstly, we introduce the necessity of a logistic hub strategy for Korea. In order to develop a successful strategy, we consider the 'free trade zone' model of the Netherlands and China. We develop a realistic and suitable model for Korea based on this Jree trade zone' model. Our proposal for a successful logistic hub strategy for Korea is the fulfillment of the following six objectives: 1) security of market accessibility, 2) improvement of the logistic system, 3) improvement of the education system, 4) improvement of the tax system, 5) assurance of labor market flexibility, and 6) development of an appealing living environment for foreigners.
Abhilash Acharya and Bijaya Mishra
Infrastructure adds pace and efficiency into India’s progress. It is a country which has embraced the notion of a knowledge economy of late, and thus raised the importance of…
Abstract
Purpose
Infrastructure adds pace and efficiency into India’s progress. It is a country which has embraced the notion of a knowledge economy of late, and thus raised the importance of infrastructure consulting per se. The study aims to cover the consequent but underexplored role of organizational structure (OS) vis-à-vis knowledge retention (KR) in this sector.
Design/methodology/approach
For conducting the research, the sampling organization that has been chosen is an infrastructure consulting organization. The researchers had undertaken an exploratory study to find out the dynamics between OS and KR. A qualitative approach has thus been adopted and the application of thematic analysis found place in conducting the research. The themes and sub-themes generated from the research, aligned with the theoretical backdrop, gave rise to a schematic model explaining the relationship between OS and KR.
Findings
From the above themes and sub-themes along with possible relationships which emerged from the study, the researchers observed that the theme “organizational structure” had a significant relationship with the sub-theme “knowledge retention”. In the order, what was the most noteworthy was that designing of an OS had a refined and somewhat directed influence on KR in the organization.
Originality/value
This paper tries to uncover the relationship between an organization’s structure formation and the key aspect of knowledge management cycle, which is KR. This shall be helpful for both academics (who can make advancements by testing the relationship in other contexts) and practitioners (who can look forward to minimizing business losses through the concept of KR).
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Maged A.I. El‐Shaarawi, Esmail M.A. Mokheimer and Ahmad Jamal
To explore the effect of the annulus geometrical parameters on the induced flow rate and the heat transfer under the conjugate (combined conduction and free convection) thermal…
Abstract
Purpose
To explore the effect of the annulus geometrical parameters on the induced flow rate and the heat transfer under the conjugate (combined conduction and free convection) thermal boundary conditions with one cylinder heated isothermally while the other cylinder is kept at the inlet fluid temperature.
Design/methodology/approach
A finite‐difference algorithm has been developed to solve the bipolar boundary‐layer equations for the conjugate laminar free convection heat transfer in vertical eccentric annuli.
Findings
Numerical results are presented for a fluid of Prandtl number, Pr=0.7 in eccentric annuli. The geometry parameters of NR2 and E (the fluid‐annulus radius ratio and the eccentricity, respectively) have considerable effects on the results.
Practical implications
Applications of the obtained results can be of value in the heat‐exchanger industry, in cooling of underground electric cables, and in cooling small vertical electric motors and generators.
Originality/value
The paper presents results that are not available in the literature for the problem of conjugate laminar free convection in open‐ended vertical eccentric annular channels. Geometry effects having been investigated by considering fluid annuli having radii ratios NR2=0.1 and 0.3, 0.5 and 0.7 and four values of the eccentricity E=0.1, 0.3, 0.5 and 0.7. Moreover, practical ranges of the solid‐fluid conductivity ratio (KR) and the wall thicknesses that are commonly available in pipe standards have been investigated. Such results are very much needed for design purposes of heat transfer equipment.
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HongJun Son, Jonghwan Park, Heecheul Kim, Young Hak Lee and Dae-Jin Kim
This paper aims to propose a generalized finite element technique that can accurately approximate the solution of the flexural-shear cantilever model of wall-frame structures…
Abstract
Purpose
This paper aims to propose a generalized finite element technique that can accurately approximate the solution of the flexural-shear cantilever model of wall-frame structures proposed by Heidebrecht and Stafford Smith.
Design/methodology/approach
This approach adopts scaled monomials as enrichment functions, and they are highly effective in accurately capturing the solution of the problem, as it consists of smooth functions such as polynomials, hyperbolic and trigonometric functions. Several numerical experiments are performed on the static and modal analyses of the flexural-shear cantilever wall-frame structures using the proposed generalized finite element method (GFEM), and their accuracies are compared with those obtained using the standard finite element method.
Findings
The proposed GFEM is able to achieve theoretical convergence rates of the static and modal analyses, which are, in principle, identical to those of the standard FEM, for various polynomial orders of its shape functions such as quadratic, cubic and quartic orders. The proposed GFEM with quartic enrichment functions can provide more accurate solutions than the standard FEM, and thus can be effectively used at the initial design stage of high-rise wall-frame structures.
Originality/value
This work is the first paper where the GFEM is applied to the analysis of high-rise wall-frame structures, and the developed technique can be used as a good analysis tool at the initial design stage.
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