Don Mah, Juan D. Manrique, Haitao Yu, Mohamed Al‐Hussein and Reza Nasseri
This paper aims to establish a baseline for carbon dioxide (CO2) emissions quantification in the current residential construction process. Opportunities to reduce the…
Abstract
Purpose
This paper aims to establish a baseline for carbon dioxide (CO2) emissions quantification in the current residential construction process. Opportunities to reduce the environmental footprint of the homebuilding process are also identified.
Design/methodology/approach
CO2 emissions of various house construction stages are quantified and utilised in a 3D building information model. This allows rapid emission computations for various house sizes, designs and materials. An intelligent database calculates emissions for different house styles with different construction processes.
Findings
Two construction stages (basement walls foundation and framing) were identified as high CO2 emissions contributors. In addition, equipment operation on site, transportation to and from the site and heating for curing concrete were identified as the main sources of emissions during construction.
Originality/value
The paper addresses the limited attention given to CO2 emissions during the actual construction process. The introduction of building information modeling for quantifying emissions in the construction process is of significant value. This research is pertinent to the international homebuilding industry and homebuyers who all have a role in mitigating CO2 emissions.
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Amin Mahmoudi, Mohammad Reza Feylizadeh and Davood Darvishi
The purpose of this paper is to examine the shortcomings and problems associated with the method proposed by Razavi Hajiagha et al. (2012).
Abstract
Purpose
The purpose of this paper is to examine the shortcomings and problems associated with the method proposed by Razavi Hajiagha et al. (2012).
Design/methodology/approach
A multi-objective approach is proposed to solve the grey linear programming problems. In this method, the grey linear problem is converted into a multi-objective problem and then solved.
Findings
According to the numerical example presented in the study by Razavi Hajiagha et al. (2012), this method does not have a correct solution because the solution does not satisfy the constraints and the upper bounds of the variables are equal or less than their lower bound.
Originality/value
In recent years, various methods have been proposed for solving grey linear programming problems. Razavi Hajiagha et al. (2012) proposed a multi-objective approach to solve grey linear programming problems, but this method does not have a correct solution and using this method in other researches studies can reduce the value of the grey system theory.
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Hassan F. Gholipour, Elias Oikarinen and Reza Tajaddini
The purpose of this study is to examine the interaction between banks’ lending to public and private sectors and house prices using data from the Iranian banking system including…
Abstract
Purpose
The purpose of this study is to examine the interaction between banks’ lending to public and private sectors and house prices using data from the Iranian banking system including, commercial government-owned banks (CGBs), specialized government-owned banks and private banks.
Design/methodology/approach
The authors use quarterly data from the second quarter of 2004 to the first quarter of 2016 and apply structural vector autoregression models.
Findings
The results show that: a positive shock to the loan supply to the private sector triggers a positive response from house prices; a positive shock to the loan supply to the public sector does not trigger a positive response from house prices; house price appreciations contribute significantly to banks’ lending to the public sector but not lending to the private sector; each loan supply by three different types of banks influences house prices positively; and CGBs’ lending to the private sector does not respond to house price shocks.
Originality/value
Although the relationship between banks’ lending and house prices is well-established in the literature, existing studies have not yet examined whether bank ownership matters for the link between banks’ lending and house prices.
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Mohammad Tavassoli, Amirali Fathi and Reza Farzipoor Saen
The purpose of this study is to propose a novel super-efficiency DEA model to appraise the relative efficiency of DMUs with zero data and stochastic data. Our model can work with…
Abstract
Purpose
The purpose of this study is to propose a novel super-efficiency DEA model to appraise the relative efficiency of DMUs with zero data and stochastic data. Our model can work with both variable returns to scale (VRS) and constant returns to scale (CRS).
Design/methodology/approach
This study proposes a new stochastic super-efficiency DEA (SSDEA) model to assess the performance of airlines with stochastic and zero inputs and outputs.
Findings
This paper proposes a new analysis and contribution to the knowledge of efficiency assessment with stochastic super-efficiency DEA model by (1) using input saving and output surplus index for efficient DMUs to get the optimal solution; (2) obtaining efficiency scores from the proposed model that are equivalent to original stochastic super-efficiency model when feasible solutions exist. A case study is given to illustrate the applicability of our proposed model. Also, poor performance reasons are identified to improve the performance of inefficient airlines.
Originality/value
For the first time, a new SSDEA model for ranking DMUs is proposed. The introduced model produces a feasible solution when dealing with zero input or output. This paper applies the input saving and output surplus concept to rectify the infeasibility problem in the stochastic DEA model.
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A.M. Mohamad, Dhananjay Yadav, Mukesh Kumar Awasthi, Ravi Ragoju, Krishnendu Bhattacharyya and Amit Mahajan
The purpose of the study is to analytically as well as numerically investigate the weight of throughflow on the onset of Casson nanofluid layer in a permeable matrix. This study…
Abstract
Purpose
The purpose of the study is to analytically as well as numerically investigate the weight of throughflow on the onset of Casson nanofluid layer in a permeable matrix. This study examines both the marginal and over stable kind of convective movement in the system.
Design/methodology/approach
A double-phase model is used for Casson nanofluid, which integrates the impacts of thermophoresis and Brownian wave, whereas for flow in the porous matrix the altered Darcy model is occupied under the statement that nanoparticle flux is disappear on the boundaries. The resultant eigenvalue problem is resolved analytically as well as numerically with the help of Galerkin process with the Casson nanofluid Rayleigh–Darcy number as the eigenvalue.
Findings
The findings revealed that the throughflow factor postpones the arrival of convective flow and reduces the extent of convective cells, whereas the Casson factor, the Casson nanoparticle Rayleigh–Darcy number and the reformed diffusivity ratio promote convective motion and also decrease the extent of convective cells.
Originality/value
Controlling the convective movement in heat transfer systems that generate high heat flux is a real mechanical challenge. The proposed framework proved that the use of throughflow is one of the most important ways to control the convective movement in Casson nanofluid. To the best of the authors’ knowledge, no inspection has been established in the literature that studies the outcome of throughflow on the Casson nanofluid convective flow in a porous medium layer. However, the convective flow of Casson nanofluid finds many applications in improving heat transmission and energy efficiency in a range of thermal systems, such as the cooling of heat-generating elements in electronic devices, heat exchangers, pharmaceutical practices and hybrid-powered engines, where throughflow can play a significant role in controlling the convective motion.