Prefabrication is a promising method for minimizing construction waste since it is conducted in a controlled environment. This paper develops a simulation model for quantitatively evaluating the ...potential of prefabrication on construction waste reduction by considering interaction behaviors among factors influencing the application of prefabrication and construction waste reduction during the design stage. The theory of planned behavior is applied to determine the system boundary, and a system dynamic model is applied for establishing the simulation model. A case project in Anhui, China, is selected for demonstrating the established model. Results show that the (1) Application of prefabrication method contributes to construction waste reduction by reducing material wastes and reworking due to design changes. (2) Impacts of prefabrication method on concrete waste reduction is the most significant. (3) Increasing investment on designers’ professional training and strengthening policies is two efficient strategies to make full use of the potential of the prefabrication method on construction waste reduction during the design stage. The developed model can offer designers as well as policymakers with references for applying prefabrication method for construction waste reduction by comparing outcomes under various scenarios with different strategies and policies ahead of implementation.
Major projects are the important platform for enhancing a country’s comprehensive national power and strengthening its capacity for independent innovation. Although major projects in China have made ...remarkable achievements, willingness to cooperate and innovate has not achieved the desired target. In this paper, the evolutionary game model of cooperative innovation behavior of general contractors and subcontractors is constructed by considering reputational factors. Through theoretical derivation, the influence of the distribution ratio of collaborative innovation benefit, spillover technology absorption capacity, and reputation discounting coefficient on innovation behavior is analyzed. Finally, MATLAB software is used to simulate the dynamic evolution process of strategy selection. The results show that (1) a reasonable benefit distribution coefficient can promote the evolution of innovation behavior in a positive direction; (2) both the reduction of innovation cost and the increase of spillover technology absorption capacity can make the innovation subject more inclined to choose the active collaborative innovation strategy; and (3) it is the higher-than-threshold reputation loss that can effectively inhibit the “free-rider” behavior. The research conclusions and managerial implications can provide reference for improving the willingness to cooperate in major projects’ technology innovation.
Due to the increasing number of people traveling by air, the passenger flow at the airport is increasing, and the problem of passenger drop-off and pickup has a huge impact on urban traffic. The ...difficulty of taking a taxi at the airport is still a hot issue in the society. Aiming at the problem of optimizing the allocation of taxi resource, this paper is based on the cost-benefit analysis method to determine the factors that affect the taxi driver’s decision-making. The mathematical methods such as function equation, BP neural network algorithm, and queuing theory were used to establish a complete decision-making model for taxi drivers and an optimization model of dispatching efficiency at the airport. A conclusion has been drawn that the allocation of airport taxi resource should be arranged closely related to drivers’ revenue and the layout of airport line.
•The dynamic game of supply chain decision-making behaviors is investigated.•The study adopts backward induction method to analyze the green supply chain model.•The reasonable green technology ...subsidies can promote greenness of building materials.•Green building material manufacturers need to set rational green technology output.
The national priority of carbon neutrality and decarbonization goals drive the transformation and upgrading of China’s construction industry. The production of green building materials is one of the key ways to decrease carbon emission. To better promote the green development of the construction industry and the realization of the decarbonization goals, a supply-chain system under technology subsidies, inclusive of a general contractor, two green building material manufacturers, is investigated. The Stackelberg model of green building material supply chain is constructed to explore how the green technology innovation of supply chain main body is affected by the technology subsidy. Meanwhile, the backward induction method is utilized to analyze the technology innovation decision-making behavior of green building material players of supply chain under a dynamic game. MATLAB software is used to simulate the stability and dynamic changes of the system in the long-term game. The results show that the decision-making stability of green building material supply chain is beneficial to the stability of supply chain system. The technology subsidy standard with reasonable policy promotes the degree of green building materials to achieve the maximum. However, once the adjustment coefficient of decision-making variables of the main body of the supply chain is large, the supply chain system will fall into chaos and disorder through bifurcation. The delayed feedback control method thus needs to be applied to control chaos, to ensure the sustainable and healthy development of the supply chain of green building materials. This study expands the application scenario of complex system theory in construction supply chain. It also provides theoretical guides for the government to formulate policies to encourage the promotion of green building materials.
To promote low-carbon development of the construction industry and popularize green buildings (GBs), considering the influence of marketing efforts and innovation capability on GB market demand, this ...paper constructs multiple incentive decision models based on contract theory, analyzes developers’ decision-making behaviors for incentivizing contractors’ green technology innovation (GTI) under different incentive decision models; and explores the impacts of greenness preference and service quality preference on contract prices, sales prices, innovation levels and marketing effort levels. In addition, the impacts of marketing effort cost coefficient and innovation capability on innovation levels, marketing effort levels and developers’ profits are simulated through parameter assignment and computer software. The results show that greenness preference and service quality preference have positive impacts on developers’ and contractors’ decisions and profits; under the decision model based on innovation level, the developers maximize profits, but the developers’ marketing effort levels and contractors’ innovation levels are lower at this time; under the decision model based on cost-sharing, the contractors have the highest innovation levels and achieve optimal profits, while the innovation capability can promote innovative activities. The results of the study have guiding significance for enhancing the levels of GTI and promoting the development of GBs.
In China, driven by the national “3060” double carbon targets (i.e., reaching peak carbon emissions by 2030 and carbon neutrality by 2060), green housing has become one of the major fields to reduce ...carbon emissions, facilitating the achievement of the double carbon targets. Promoting the growth of green housing is an important way for the real estate industry to achieve low-carbon transformation and improve the quality of housing. Meanwhile, the construction industry also can benefit from green housing to achieve its energy conservation and emission reduction targets. Therefore, it is critical to boost and maintain the sustainable growth of the green housing market in China. However, the literature has not focused attention on the market behavior of the green housing market in China. This study proposes a tripartite evolutionary game model to investigate the subject behavior of the green housing market in China. This model consists of three major subjects in a green housing market: developers, consumers, and governments. Based on this model, this study analyzes the stability of the strategy options for each stakeholder and identifies the stable conditions of strategy portfolios to reach the equilibrium points of the game system. The validity of the proposed tripartite evolutionary game model is tested through the simulation of the impacts from various factors on system evolution. According to the impacts of factors and the stable conditions of strategies, this paper puts forward relevant policy suggestions for the healthy and sustainable growth of China’s green housing market.
Guanxi, a Chinese term that defines social networks of power and benefits, can be divided into inter-personal and inter-organizational relationships. Guanxi significantly influences construction ...innovation in China. Many studies have examined the relationship between guanxi and construction innovation at the project or organizational level. However, few of these studies explain how guanxi might affect an individual’s innovative behaviour from a double-level perspective. This paper builds on social capital theory and social exchange theory to examine guanxi’s role in motivating innovative behaviour in a China-specific construction context. It investigates the main effects of inter-personal relationships on innovative behaviour, the mediating effects of knowledge sharing, and the cross-level moderating effects of inter-organizational relationships. These elements were tested using a survey that received 178 responses from 35 different organizations. The results were analysed using Hierarchical Linear Modelling (HLM) and revealed that inter-personal relationships have positive influences on innovative behaviour, thus highlighting the partial mediating effects of knowledge sharing. In addition, the analyses showed that inter-organizational relationships augment inter-personal relationships and knowledge sharing on innovative behaviour by cross-level interaction. The research findings enhance an understanding of guanxi and innovative behaviour in China-specific construction project settings, as well as verifying the significance of guanxi in stimulating innovative behaviour.
Corynebacterium glutamicum is an important industrial metabolite producer that is difficult to genetically engineer. Although the Streptococcus pyogenes (Sp) CRISPR-Cas9 system has been adapted for ...genome editing of multiple bacteria, it cannot be introduced into C. glutamicum. Here we report a Francisella novicida (Fn) CRISPR-Cpf1-based genome-editing method for C. glutamicum. CRISPR-Cpf1, combined with single-stranded DNA (ssDNA) recombineering, precisely introduces small changes into the bacterial genome at efficiencies of 86-100%. Large gene deletions and insertions are also obtained using an all-in-one plasmid consisting of FnCpf1, CRISPR RNA, and homologous arms. The two CRISPR-Cpf1-assisted systems enable N iterative rounds of genome editing in 3N+4 or 3N+2 days. A proof-of-concept, codon saturation mutagenesis at G149 of γ-glutamyl kinase relieves L-proline inhibition using Cpf1-assisted ssDNA recombineering. Thus, CRISPR-Cpf1-based genome editing provides a highly efficient tool for genetic engineering of Corynebacterium and other bacteria that cannot utilize the Sp CRISPR-Cas9 system.
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