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Article
Publication date: 21 January 2019

Habib Karimi, Hossein Ahmadi Danesh Ashtiani and Cyrus Aghanajafi

This paper aims to examine total annual cost from economic view mixed materials heat exchangers based on three optimization algorithms. This study compares the use of three…

250

Abstract

Purpose

This paper aims to examine total annual cost from economic view mixed materials heat exchangers based on three optimization algorithms. This study compares the use of three optimization algorithms in the design of economic optimization shell and tube mixed material heat exchangers.

Design/methodology/approach

A shell and tube mixed materials heat exchanger optimization design approach is expanded based on the total annual cost measured by dividing the costs of the heat exchanger to area of surface and power consumption. In this study, optimization and minimization of the total annual cost is considered as the objective function. There are three types of exchangers: cheap, expensive and mixed. Mixed materials are used in corrosive flows in the heat exchanger network. The present study explores the use of three optimization techniques, namely, hybrid genetic-particle swarm optimization, shuffled frog leaping algorithm techniques and ant colony optimization.

Findings

There are three parameters as decision variables such as tube outer diameter, shell diameter and central baffle spacing considered for optimization. Results have been compared with the findings of previous studies to demonstrate the accuracy of algorithms.

Originality/value

The present study explores the use of three optimization techniques, namely, hybrid genetic-particle swarm optimization, shuffled frog leaping algorithm techniques and ant colony optimization. This study has demonstrated successful application of each technique for the optimal design of a mixed material shell and tube heat exchanger from the economic view point.

Details

Journal of Engineering, Design and Technology, vol. 17 no. 2
Type: Research Article
ISSN: 1726-0531

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Article
Publication date: 22 July 2020

K. Vafai, Ambreen A. Khan, G. Fatima, Sadiq M. Sait and R. Ellahi

This paper aims to investigate the effect of Powell–Eyring fluid induced by a stretched sheet. Heat and mass transfer under the influence of magnetic dipole over a stretching…

138

Abstract

Purpose

This paper aims to investigate the effect of Powell–Eyring fluid induced by a stretched sheet. Heat and mass transfer under the influence of magnetic dipole over a stretching sheet are taken into account.

Design/methodology/approach

Nonlinear coupled governing equations are solved using the optimal homotopy asymptotic technique, and a computer software package BVPh 2.0 is used for numerical computations.

Findings

Impact of significant quantities is graphically examined. It is seen that the heat transfer deceases for higher values of viscous dissipation parameter, radiation parameter, Dufour number, whereas it increases for bigger values of Prandtl number. The numerical results have been validated through comparison with existing literature as a special case of proposed model and perceived that the Soret number has reining role to increase the rate of heat transfer.

Originality/value

To the best of the authors’ knowledge, this study is reported for the first time.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 31 no. 4
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 27 September 2021

Saeed Ghorbani, Ali Jabari Moghadam, Amin Emamian, R. Ellahi and Sadiq M. Sait

In this paper aims to investigate the numerical simulation of the electroosmotic flow of the Carreau-Yasuda model in the rectangular microchannel. Electromagnetic current is…

297

Abstract

Purpose

In this paper aims to investigate the numerical simulation of the electroosmotic flow of the Carreau-Yasuda model in the rectangular microchannel. Electromagnetic current is generated by applying an effective electric field in the direction of the current.

Design/methodology/approach

The non-Newtonian model used is the five-constant Carreau-Yasuda model which the non-Newtonian properties of the fluid can be well modeled. Using the finite difference method, the potential values at all points in the domain are obtained. Then, the governing equations (momentum conservation) and the energy equation are segregated and solved using a finite difference method.

Findings

In this paper, the effect of various parameters such as Weisenberg number, electrokinetic diameter, exponential power number on the velocity field and Brinkman and Pecklet dimensionless numbers on temperature distribution are investigated. The results show that increasing the Weissenberg dimensionless number and exponential power and diameter parameters reduces the maximum velocity field in the microchannel.

Originality/value

To the best of the authors’ knowledge, this study is reported for the first time.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 32 no. 7
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 11 July 2022

Abdul Habib Zaray, Abid Hasan, Sparsh Johari, Parvez Ahmad Hashmat and Kumar Neeraj Jha

The poor quality of construction work in war-affected regions is a significant issue. The large-scale destruction to the existing infrastructure from the war necessitates cost and…

422

Abstract

Purpose

The poor quality of construction work in war-affected regions is a significant issue. The large-scale destruction to the existing infrastructure from the war necessitates cost and time-efficient delivery of construction projects during and post-war to bring normalcy to affected lives and places. Consequently, there is always a tendency to finish construction projects in the shortest possible time on a limited budget without following the proper quality management processes. However, the poor quality of construction projects continues to affect the country's development, growth, credibility, reputation, and public safety for several years after the war. To this end, the present study was conducted to evaluate the significant attributes and factors contributing to the poor quality of construction projects in the war-affected Afghan construction sector.

Design/methodology/approach

A total of 31 attributes influencing construction project quality were ranked based on 110 completed survey responses collected from Afghan construction professionals. Moreover, independent samples t-test, Spearman's rank correlation test, and exploratory factor analysis were conducted.

Findings

The study found a moderate consensus between clients and contractors on attributes' rankings. In addition, the independent samples t-test showed statistically significant differences in means values of responses from clients and contractors for eight attributes. Based on factor analysis, 19 important attributes (median value greater than or equal to four) were classified into 4 latent factors – (1) poor-quality assurance and control, (2) unethical practices, (3) design and drawing errors, and (4) knowledge and skills gap.

Originality/value

Evaluating the factors affecting the quality of construction projects will help clients, government departments, and construction practitioners improve the construction quality management practices. The findings will also inform the policies and procedures of international aid providers.

Details

Engineering, Construction and Architectural Management, vol. 30 no. 10
Type: Research Article
ISSN: 0969-9988

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Book part
Publication date: 1 January 2014

Eric J. Miller

Abstract

Details

Handbook of Microsimulation Modelling
Type: Book
ISBN: 978-1-78350-570-8

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Article
Publication date: 15 September 2023

Tooraj Karimi and Mohamad Ahmadian

Competition in the banking sector is more complex than in the past, and survival has become more difficult than before. The purpose of this paper is to propose a grey methodology…

128

Abstract

Purpose

Competition in the banking sector is more complex than in the past, and survival has become more difficult than before. The purpose of this paper is to propose a grey methodology for evaluating, clustering and ranking the performance of bank branches with imprecise and uncertain data in order to determine the relative status of each branch.

Design/methodology/approach

In this study, the two-stage data envelopment analysis model with grey data is applied to assess the efficiency of bank branches in terms of operations. The result of grey two-stage data envelopment analysis model is a grey number as efficiency value of each branch. In the following, the branches are classified into three grey categories of performance by grey clustering method, and the complete grey ranking of branches are performed using “minimax regret-based approach” and “whitening value rating”.

Findings

The results show that after grey clustering of 22 branches based on grey efficiency value obtained from the grey two-stage DEA model, 6 branches are assigned to “excellent” class, 4 branches to “good” class and 12 branches to “poor” class. Moreover, the results of MRA and whitening value rating models are integrated, and a complete ranking of 22 branches are presented.

Practical implications

Grey clustering of branches based on grey efficiency value can facilitate planning and policy-making for branches so that there is no need to plan separately for each branch. The grey ranking helps the branches find their current position compared to other branches, and the results can be a dashboard to find the best practices for benchmarking.

Originality/value

Compared with traditional DEA methods which use deterministic data and consider decision-making units as black boxes, in this research, a grey two-stage DEA model is proposed to evaluate the efficiency of bank branches. Furthermore, grey clustering and grey ranking of efficiency values are used as a novel solution for improving the accuracy of grey two-stage DEA results.

Details

Grey Systems: Theory and Application, vol. 14 no. 1
Type: Research Article
ISSN: 2043-9377

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Book part
Publication date: 14 November 2006

Ahmad R. Jalali-Naini

Abstract

Details

Explaining Growth in the Middle East
Type: Book
ISBN: 978-0-44452-240-5

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Article
Publication date: 26 May 2022

Mahpara Naeem, Syed Tehseen Jawaid and Sadaf Mustafa

This paper aims to review and highlight the gaps in the research streams of the technological acceptance model (TAM) associated with e-banking services. The introduction of TAM as…

1306

Abstract

Purpose

This paper aims to review and highlight the gaps in the research streams of the technological acceptance model (TAM) associated with e-banking services. The introduction of TAM as a decision-making process from individual and organizational perspectives is the core purpose of this paper.

Design/methodology/approach

This study is based on concept-centric reviews and synthesizing of previous research. Data are extracted from a systematic literature review published from 1975 to 2021 under the preferred reporting items for systematic review and meta-analyses statement.

Findings

This review explored that theory of reasoned action and theory of planned behavior are the basic theories proceeding to TAM evolution. TAM has been extended to its three versions, which are designed and modified for different contexts and cultures. Previously, the risk-return approach, theory of trust and perceived value were the major constructs or modifications in TAM. Now, TAM has been designed for measuring customers’ perception of any technological advancement.

Research limitations/implications

This review is limited to major additive constructs in modified TAM concerning e-banking services, which can be expanded to different cultures and contexts. This study sketched TAM as a decision-making model associated with the factors influencing any technological advancement. So, the proposed conceptual framework is applicable for the behavioral analysis of technological adoption from individual and organizational perspectives in any field.

Originality/value

This review designed a bi-dimensional conceptual model of TAM as a decision-making process for e-services that has not been identified yet in any study from organizations’ and customers’ perspectives.

Details

Journal of Modelling in Management, vol. 18 no. 3
Type: Research Article
ISSN: 1746-5664

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Article
Publication date: 6 March 2017

Emita W. Astami, Rusmin Rusmin, Bambang Hartadi and John Evans

The purpose of this paper is to examine the effect of culture and audit quality on managers’ decisions regarding accounting accruals. It focuses on companies experiencing…

2593

Abstract

Purpose

The purpose of this paper is to examine the effect of culture and audit quality on managers’ decisions regarding accounting accruals. It focuses on companies experiencing excessive free cash flow, as these companies have been associated with an agency problem.

Design/methodology/approach

This study measures the magnitude of discretionary accruals as a proxy for earnings management using the cross-sectional modified Jones model. Excessive free cash flow is scrutinized by the method used by Chung et al. (2005). Listed companies in nine countries in the Asia-Pacific region are represented in this study. The statistical analyses are used to examine the influence of cultural aspect, the role of external monitoring by high-quality auditors and the earnings management practice in the companies with excessive free-cash-flow.

Findings

The empirical results presented in this paper provide support for the proposition that managers of companies with excessive free-cash-flow will make investment decisions that are not always in the best interest of the shareholders and use accounting discretion to increase reported earnings. This study provides empirical evidence that these companies have been associated with an agency problem and the role of external auditor persists in a setting, where cultural differences prevail in across countries.

Practical implications

In cross-border trade and investment, the findings provide the opportunity to exploit a setting, where cultural differences prevail, whereas other potentially influential variables, including the role of external monitoring by high-quality auditors, are relatively constant across countries.

Originality/value

Previous studies (Leuz et al., 2003; and Enomoto et al., 2015) examine factors influencing earnings management internationally have concentrated on legal institutions and investor protection. Han et al. (2010) completed a cross-country study on the effects of national culture on earnings management. This study focuses on companies across countries experiencing with excessive free cash flow and examines the cultural aspect and the effectiveness of external monitoring by high-quality auditors operating in different countries in mitigating managerial opportunism.

Details

International Journal of Accounting & Information Management, vol. 25 no. 1
Type: Research Article
ISSN: 1834-7649

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Article
Publication date: 19 December 2024

Pana Suttakul, Itthidet Thawon, Pruettha Nanakorn, Jaroon Rungamornrat, Elena Atroshchenko and Duy Vo

This study examines the accuracy of a homogenization scheme for the linear buckling analysis of structures assembled from beam-based lattice plates. Regardless of in-plane acting…

44

Abstract

Purpose

This study examines the accuracy of a homogenization scheme for the linear buckling analysis of structures assembled from beam-based lattice plates. Regardless of in-plane acting loads, the buckling behavior is characterized by the abrupt out-of-plane deformation. Apparently, if the lattice plates are modeled as homogenized ones, the out-of-plane effective material properties should be considered. However, as prevalently implemented in literature, the in-plane effective material properties are assigned to the homogenized plates for the linear buckling analysis, and thus, the results are erroneous.

Design/methodology/approach

The linear buckling analysis is performed by two finite element models, i.e. the high- and low-fidelity finite element models. In the former one, each strut of the lattice structures is modeled as an Euler–Bernoulli beam, and thus, all the geometrical features are explicitly simulated. On the other hand, the low-fidelity one involves the homogenized plates having the out-of-plane effective material properties determined from the lattice counterparts using an energy-based homogenization method.

Findings

The accuracy of the homogenization scheme is confirmed by the comparison of results obtained by the high- and low-fidelity finite element models. Six topological configurations of the unit cells are considered, and the first five buckling modes are inspected. In all examinations, the low-fidelity finite element model offers the acceptable level of accuracy, i.e. the relative difference between two finite element models is lower than 5%. Furthermore, it is recommended to use the out-of-plane effective material properties rather than the in-plane ones to ensure the precise simulation.

Originality/value

The current study is original. In literature, there are some studies regarding the buckling analysis of lattice plates or panels with out-of-plane material properties. However, these studies use the analytical approach, and consequently, they are confined to lattice structures whose geometry is simple. In the present paper, structures assembled from beam-based lattice plates are examined. It can be noticed that these structures can have complex geometry. Therefore, the feasibility and accuracy of using out-of-plane effective material properties with homogenized plates for the linear buckling analysis of lattice plates are validated.

Details

International Journal of Structural Integrity, vol. 16 no. 1
Type: Research Article
ISSN: 1757-9864

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