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Article
Publication date: 29 May 2019

Mehdi Abbasi, Nahid Mokhtari, Hamid Shahvar and Amin Mahmoudi

The purpose of this paper is to solve large-scale many-to-many hub location-routing problem (MMHLRP) using variable neighborhood search (VNS). The MMHLRP is a combination of a…

179

Abstract

Purpose

The purpose of this paper is to solve large-scale many-to-many hub location-routing problem (MMHLRP) using variable neighborhood search (VNS). The MMHLRP is a combination of a single allocation hub location and traveling salesman problems that are known as one of the new fields in routing problems. MMHLRP is considered NP-hard since the two sub-problems are NP-hard. To date, only the Benders decomposition (BD) algorithm and the variable neighborhood particle swarm optimization (VNPSO) algorithm have been applied to solve the MMHLRP model with ten nodes and more (up to 300 nodes), respectively. In this research, the VNS method is suggested to solve large-scale MMHLRP (up to 1,000 nodes).

Design/methodology/approach

Generated MMHLRP sample tests in the previous work were considered and were added to them. In total, 35 sample tests of MMHLRP models between 10 and 1,000 nodes were applied. Three methods (BD, VNPSO and VNS algorithms) were run by a computer to solve the generated sample tests of MMHLRP. The maximum available time for solving the sample tests was 6 h. Accuracy (value of objective function solution) and speed (CPU time consumption) were considered as two major criteria for comparing the mentioned methods.

Findings

Based on the results, the VNS algorithm was more efficient than VNPSO for solving the MMHLRP sample tests with 10–440 nodes. It had many similarities with the exact BD algorithm with ten nodes. In large-scale MMHLRP (sample tests with more than 440 nodes (up to 1,000 nodes)), the previously suggested methods were disabled to solve the problem and the VNS was the only method for solving samples after 6 h.

Originality/value

The computational results indicated that the VNS algorithm has a notable efficiency in comparison to the rival algorithm (VNPSO) in order to solve large-scale MMHLRP. According to the computational results, in the situation that the problems were solved for 6 h using both VNS and VNPSO, VNS solved the problems with more accuracy and speed. Additionally, VNS can only solve large-scale MMHLRPs with more than 440 nodes (up to 1,000 nodes) during 6 h.

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Article
Publication date: 13 May 2020

Amin Mahmoudi, Mehdi Abbasi, Xiaopeng Deng, Muhammad Ikram and Salman Yeganeh

Selecting a suitable contract to outsource construction projects is an ongoing concern for project managers and organizational directors. This study aims to propose a…

609

Abstract

Purpose

Selecting a suitable contract to outsource construction projects is an ongoing concern for project managers and organizational directors. This study aims to propose a comprehensive model to manage the risks of outsourced construction project contracts.

Design/methodology/approach

To employ the proposed model, firstly, the types of contracts and risks in the organization should be identified, then, to prioritize the contracts, the identified risks are considered as criteria. After receiving the experts' opinions, the best–worst method (BWM) integrated with grey relation analysis (GRA) method was used to prioritize the contracts. BWM and GRA are multi-criteria decision-making methods with different approaches and applications. In the current study, BWM has been employed to calculate the weights of criteria because it has better performance than other methods such as the analytic hierarchy process (AHP). After calculating the weights of criteria, the GRA method has been utilized for ranking the alternatives.

Findings

According to the results obtained from the case study, the cost plus award fee contract is the most suitable alternative for outsourcing construction projects. The proposed methodology can be practically applied through different types of the projects such as construction or “engineering, procurement and construction”.

Originality/value

To the best of our knowledge, this is the first time a conceptual model has been proposed to select an appropriate contract for construction projects. Also, for the first time, the BWM integrated with GRA method has been used to prioritize project contracts based on the potential risks. The proposed model can contribute to project managers for selecting a suitable contract with the least risk in construction projects.

Details

Grey Systems: Theory and Application, vol. 10 no. 2
Type: Research Article
ISSN: 2043-9377

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Article
Publication date: 16 May 2016

Mehdi Abbasi and Mohamad Amin Kaviani

Competition in dynamic markets requires operational excellence and effective operations strategy. Hence, organizations have to evaluate their operational performance in comparison…

757

Abstract

Purpose

Competition in dynamic markets requires operational excellence and effective operations strategy. Hence, organizations have to evaluate their operational performance in comparison to their rivals. The purpose of this paper is to present an operational performance evaluation framework for analyzing and ranking the organizations based on the effectiveness of their operations strategies.

Design/methodology/approach

In this study three uncertain data envelopment analysis (DEA) models consist of fuzzy DEA (FDEA), imprecise DEA (IDEA) and Grey DEA are applied to assess the performance of organizations in terms of the operations. The applicability of the proposed framework is demonstrated through a case study at Fars province cement manufacturers of Iran.

Findings

The ranking results assist the mangers of service and manufacturing enterprises in finding out the current positions of their companies and the effectiveness of their operations strategies in comparison to their rivals. Accordingly they can make proper strategic and operational decisions to improve the performance of the operations.

Originality/value

Based on the previous literature, this is the first study which uses FDEA and IDEA methods in an operational performance evaluation problem. Furthermore this study proposes a novel framework for evaluating and ranking the operational performance of firms from the perspective of operations strategy.

Details

Management Decision, vol. 54 no. 4
Type: Research Article
ISSN: 0025-1747

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Article
Publication date: 9 May 2022

Erfan Najaf, Hassan Abbasi and Seyed Mehdi Zahrai

Today, using lightweight structural concrete plays a major role in reducing the damage to concrete structures. On the other hand, lightweight concretes have lower compressive and…

186

Abstract

Purpose

Today, using lightweight structural concrete plays a major role in reducing the damage to concrete structures. On the other hand, lightweight concretes have lower compressive and flexural strengths with lower impact resistance compared to ordinary concretes. The aim of this study is to investigate the effect of simultaneous use of waste glass powder, microsilica and polypropylene fibers to make sustainable lightweight concrete that has high compressive and flexural strengths, ductility and impact resistance.

Design/methodology/approach

In this article, the lightweight structural concrete is studied to compensate for the lower strength of lightweight concrete. Also, considering the environmental aspects, microsilica as a partial replacement for cement, waste glass powder instead of some aggregates and polypropylene fibers are used. Microsilica was used at 8, 10 and 12 wt% of cement. Waste glass powder was added to 20, 25 and 30 wt% of aggregates, while fibers were used at 0.5, 1 and 1.5 wt% of cement.

Findings

After making the experimental specimens, compressive strength, flexural strength and impact resistance tests were performed. Ultimately, it was concluded that the best percentage of used microsilica and glass powder was equal to 10 and 25%, respectively. Furthermore, using 1.5 wt% of fibers could significantly improve the compressive and flexural strengths of lightweight concrete and increase its impact resistance at the same time. For constructing a five-story building, by replacing cement with microsilica by 10 wt%, the amount of used cement is reduced by 5 tons, consequently producing 4,752 kg less CO2 that is a significant value for the environment.

Originality/value

The study provides a basis for making sustainable lightweight concrete with high strength against compressive, flexural and impact loads.

Details

International Journal of Structural Integrity, vol. 13 no. 3
Type: Research Article
ISSN: 1757-9864

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Article
Publication date: 12 September 2018

Mahmoud Mousavi Shiri, Mahdi Salehi, Fatemeh Abbasi and Shayan Farhangdoust

In the process of reporting accounting information, the auditor’s objective is to detect possible misstatements and errors in accounting information. Audit evidence aids auditors…

744

Abstract

Purpose

In the process of reporting accounting information, the auditor’s objective is to detect possible misstatements and errors in accounting information. Audit evidence aids auditors in providing reasonable assurance about the quality of financial reporting. Studying the quality of family firms’ financial reporting is of higher importance relative to non-family firms due to lower risk of accounting manipulation. Therefore, the purpose of this paper is to examine the relationship between family ownership structure and financial reporting quality from an auditing perspective.

Design/methodology/approach

To analyze the research hypotheses, the authors use a sample data consisted of 221 companies listed on the Tehran Stock Exchange (including 52 family and 169 non-family firms) over a five-year span from 2011 to 2015.

Findings

Using multivariate regression analysis of panel data, our results indicate that audit risk in family firms is lower than their counterparts. Likewise, the findings are indicative of lower audit fees paid by family firms as compared to non-family ones. The authors also find that auditors put more effort in family firms and thus audit effort is more significant for these kinds of firms.

Originality/value

The study focuses on family ownership and financial reporting quality in a developing country like Iran and the results of the study may be beneficial to other developing nations, as Iran stock market possesses some unique features which are not normally prevailing in other equity markets, even in the Middle East.

Details

Journal of Family Business Management, vol. 8 no. 3
Type: Research Article
ISSN: 2043-6238

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Article
Publication date: 3 December 2021

Reza Behkam, Hossein Karami, Mehdi Salay Naderi and Gevork B. Gharehpetian

This study aims to use frequency response analysis, a powerful tool to detect the location and types of transformer winding faults. Proposing an effective intelligent approach for…

128

Abstract

Purpose

This study aims to use frequency response analysis, a powerful tool to detect the location and types of transformer winding faults. Proposing an effective intelligent approach for interpreting the frequency responses is the most crucial problem of this method and has created many challenges.

Design/methodology/approach

Heat maps based on appropriate statistical indices have been supplied to depict the variations in the frequency responses associated with each fault type, fault location and fault extent along the windings. Also, after analyzing the results of artificial neural network (ANN) techniques, the generalized regression neural network method is introduced as the most effective solution for the classification of transformer winding faults.

Findings

Using a comparative approach, the performance of the used indices and ANN techniques are evaluated. The results showed the proper performance of Lin’s concordance coefficient (LCC) index and the amplitude (Amp) part of the frequency response. The proposed fitting percentage (FP) index can assist the intelligent classifiers in diagnosing the radial deformation (RD) fault with the highest accuracy considering all frequency response components in the classification procedure of winding faults.

Practical implications

Various ANN techniques are used to detect and determine the type of four important faults of transformer winding, i.e. axial displacement, RD, disc space variation and short circuit. Various statistical indices, such as cross-correlation factor, LCC, standard difference area, sum of errors, normalized root-mean-square deviation and FP, are used to extract the features of the frequency responses to consider as the ANN inputs. In addition, different components of the frequency response, such as Amp, argument, real and imaginary parts are examined in this paper. To implement the proposed procedure, step by step, various types of winding faults with different locations and extents are applied on the 20 kV winding of a 1.6 MVA distribution transformer.

Originality/value

Contributions have been made in identifying and diagnosing transformer winding defects through the use of appropriate algorithms for future research.

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Article
Publication date: 12 February 2018

Mahdi Salehi, Mohammad Tahervafaei and Hossein Tarighi

The purpose of this paper is to evaluate the relationship between the characteristics of the audit committee and the board and profitability among the companies listed on the…

1941

Abstract

Purpose

The purpose of this paper is to evaluate the relationship between the characteristics of the audit committee and the board and profitability among the companies listed on the Tehran Stock Exchange (TSE) in Iran.

Design/methodology/approach

In this study, the companies listed on the TSE during the period from 2010 to 2015 are investigated. The Linear panel regression method is employed for this purpose. The independent variables of the study are composed of some corporate governance mechanisms including audit committee size, audit committee expertise, board size, board independence, chief executive officer (CEO) duality, and institutional ownership.

Findings

In spite of the fact that there does not exist any significant association between audit committee size and corporate financial performance, the results indicate that there is a positive and significant relationship between audit committee financial expertise and profitability. The authors found that the number of board members cannot affect corporate performance; moreover, duality of CEO role in Iranian companies does not affect company performance. However, the outcomes showed a positive and significant association between the proportion of outside directors on the board (board independence) and profitability at 99 percent confidence level. This implies that the role of non-executive directors in Iran is inconsistent with the stewardship theory. This is due to the fact that independent directors understand the status of business and market better than the board’s executive members. Finally, the results indicated that there is no significant association between institutional owners and Iranian companies’ performance.

Practical implications

The findings of this study will reveal more than ever the role of corporate governance mechanisms for society and users of financial statements because as tools on the CEO actions, they always have to pay attention to the implementation of corporate principles in the economic entity’ operation.

Originality/value

This is one of the most important studies that simultaneously examine the impacts of characteristics of the audit committee and the board on profitability in an emerging market, and the results of the study may give strength to Iranian as well other developing countries.

Details

Journal of Economic and Administrative Sciences, vol. 34 no. 1
Type: Research Article
ISSN: 2054-6238

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Article
Publication date: 23 December 2024

Mahmood Madhoosh, Mehdi Safari Gerayli, Javad Ramezani, Javad Babaee Khalili and Mehdi Khalilpour

This paper, on the one hand, aims to introduce a framework that helps to identify human rights accounting (HRA) factors and, on the other hand, investigates the effect of…

15

Abstract

Purpose

This paper, on the one hand, aims to introduce a framework that helps to identify human rights accounting (HRA) factors and, on the other hand, investigates the effect of accountants’ professional development (APD) on HRA.

Design/methodology/approach

The research design consists of two main parts: (1) Identifying HRA factors through interviews and evaluating the validity and reliability of the presented framework dimensions and (2) Research hypothesis testing through partial least squares in selected firms listed on Tehran Stock Exchange.

Findings

Based on the mixed method of this study, the result in the qualitative part is to provide the HRA framework of the existence of three categories; There are 6 components and 32 themes during 12 interviews. In the quantitative section, the results of the study showed that APD has a significantly positive effect on HRA.

Originality/value

The study contributes to the literature on perceptions of human rights from a social accounting perspective in an emerging economy like Iran. Because human rights accountability is an urgent challenge for companies in today’s society. However, scholars have largely disregarded the role of accounting in the process of holding companies accountable for human rights violations. This study by questioning the relationship between accounting and human rights indicates that urgent measures need to be undertaken to mainstream the legitimate human rights obligations of business entities.

Details

Journal of Advances in Management Research, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0972-7981

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Article
Publication date: 30 March 2021

Sina Mohammadi, Mehdi Tavakolan and Banafsheh Zahraie

This paper proposes an innovative intelligent simulation-based construction planning framework that introduces a new approach to simulation-based construction planning.

651

Abstract

Purpose

This paper proposes an innovative intelligent simulation-based construction planning framework that introduces a new approach to simulation-based construction planning.

Design/methodology/approach

In this approach, the authors developed an ontological inference engine as an integrated part of a constraint-based simulation system that configures the construction processes, defines activities and manages resources considering a variety of requirements and constraints during the simulation. It allows for the incorporation of the latest project information and a deep level of construction planning knowledge in the planning. The construction planning knowledge is represented by an ontology and several semantic rules. Also, the proposed framework uses the project building information model (BIM) to extract information regarding the construction product and the relations between elements. The extracted information is then converted to an ontological format to be useable by the framework.

Findings

The authors implemented the framework in a case study project and tested its usefulness and capabilities. It successfully generated the construction processes, activities and required resources based on the construction product, available resources and the planning rules. It also allowed for a variety of analyses regarding different construction strategies and resource planning. Moreover, 4D BIM models that provide a very good understanding of the construction plan can be automatically generated using the proposed framework.

Originality/value

The active integration between BIM, discrete-event simulation (DES) and ontological knowledge base and inference engine defines a new class of construction simulation with expandable applications.

Details

Engineering, Construction and Architectural Management, vol. 29 no. 2
Type: Research Article
ISSN: 0969-9988

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Article
Publication date: 9 August 2021

Heydar Esmaeili, Alireza Isfandyari-Moghaddam and Mehdi Alipour Hafezi

This paper aims to draw a roadmap for the presence of Iranian academic libraries in the cloud infrastructure.

384

Abstract

Purpose

This paper aims to draw a roadmap for the presence of Iranian academic libraries in the cloud infrastructure.

Design/methodology/approach

This research attends an applied-development one that is a part of developmental research due to its conceptual expansion, foresight and roadmap for the presence of cloud-based academic libraries and finally, becoming cloud libraries. Because of providing a roadmap template, the presence of academic digital libraries in the cloud and becoming a cloud library is applied research. Because of providing a roadmap template, academic digital libraries’ presence in the cloud and becoming a cloud library is one of the applied research areas. The statistical population of this research includes all Iranian digital academic libraries. There were 64 digital libraries out of which 59 libraries participated in completing the questionnaire.

Findings

Preliminary results from used Delphi method’s first round which was considered by 59 experts were identified typically and descriptive after appropriate component classification and editing. After identifying these factors, each of the roadmap levels in the third stage and the degree of relevance approved by the experts were reviewed and the most critical and relevant factors were identified as key components of the roadmap for the presence of cloud-based academic libraries and becoming cloud libraries. At this stage, they were selected as 24 factors, including seven factors for the first layer, eight factors for the second layer and nine factors for the third layer.

Originality/value

By introducing a roadmap for the presence of academic digital libraries in the cloud context, they will promote more and better interaction between academic libraries to offer services to users anytime and anywhere.

Details

Global Knowledge, Memory and Communication, vol. 71 no. 6/7
Type: Research Article
ISSN: 2514-9342

Keywords

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