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In multihop wireless networks, the number of neighbors has an important role in the network performance since links are dynamically formed between a node and its neighbors. This paper aims to investigate this issue.

The paper quantitatively studies the effects of the average number of neighbors in multihop wireless networks on the network connectivity, the number of hops needed to traverse a certain distance, which can be used to determine the hop diameter of a network, and the total energy consumed by packet transmission, which can be used to choose an optimum average number of neighbors that minimizes the energy consumption. This paper also presents an analysis of the energy consumption that can be applied to a wide range of access protocols and show the effect of a variety of factors.

Results show that the minimum average number of neighbors to guarantee the overall network connectivity depends on the size of a network coverage. There is a sharp knee in the network connectivity with decrease of the average number of neighbors, N. If the distance between a source and destination, d, is known, the number of hops needed to reach the destination is usually between d/R∼2d/R, where R is the transmission range. A larger average number of neighbors N leads to a smaller number of hops to traverse a certain distance, which in turn results in a smaller traffic load caused by relaying packets. However, a bigger N also causes more collisions when a contention medium access scheme is used, which leads to more energy consumed by packet transmission. The results show that the optimum N which minimizes the energy is obtained by balancing several factors affecting the energy.

The paper provides a useful study on the effects of the number of neighbors in multihop wireless networks.

The purpose of this paper is to compare women entrepreneurship in China and Vietnam by examining the motivations, success factors and problems related to establishing women-owned businesses.

The sample in this study consisted of 170 women entrepreneurs in Vietnam and 180 women entrepreneurs in China. The authors used the survey instrument developed by H.M. Chu (Chu and Katsioloudes 2001), which has been adopted in a number of small business studies since 2002. To determine whether there is a significant difference between the two countries regarding each factor of motivations, success factors and problems, the authors use the non-parametric Wilcoxon rank-sum test.

Women entrepreneurs are motived to earn more income in both China and Vietnam. Vietnamese businesswomen value intrinsic rewards such as gaining personal satisfaction and freedom. They also take business ownership as a way to reduce work–family conflict. Demonstrating the ability and gaining public recognition play a more important role when Chinese women entrepreneurs decide to establish their businesses. Both Chinese and Vietnamese women agree that good management skills are essential to achieve their goals. Women entrepreneurs in both countries share similar challenges, such as the inability to recruit and retain employees, severe competition, a weak economy and limited access to financial capital.

Given the nature of transitional economies in both countries, the government is required to improve the regulatory environment for protecting private sector employment and private property rights. Policies such as subsidies and tax incentives may assist the development of women enterprises. To support the sustainable growth of women businesses, it is suggested that the government should design effective programs that direct women entrepreneurs to move into high-growth or high-technology sectors. Training programs are also required to improve the knowledge and skills of women entrepreneurs. Making capital accessible to women is also important to stimulate entrepreneurial growth. As a further stimulus, governments should coordinate with financial institutions to provide low-cost loans or even venture capital to facilitate this process.

This study is among one of the first attempts to compare women entrepreneurship in the two transitional economies of Vietnam and China. It provides insight into motivations, success factors and problems that women entrepreneurs experienced by examining small business owners in Vietnam and China.

The need for infrastructure is growing as urbanization picks up speed, and the infrastructure REITs financing model has been crucial in reviving the vast infrastructure stock, alleviating the pressure on government funds and diversifying investment entities. This study aims to propose a framework to better assess the risks of infrastructure REITs, which can serve for the researchers and the policy makers to propose risk mitigation strategies and policy recommendations more purposively to facilitate successful implementation and long-term development of infrastructure REITs.

The infrastructure REITs risk evaluation index system is established through literature review and factor analysis, and the optimal comprehensive weight of the index is calculated using the combination weight. Then, a risk evaluation cloud model of infrastructure REITs is constructed, and experts quantify the qualitative language of infrastructure REITs risks. This paper verifies the feasibility and effectiveness of the model by taking a basic REITs project in China as an example. This paper takes infrastructure REITs project in China as an example, to verify the feasibility and effectiveness of the cloud evaluation method.

The research outcome shows that infrastructure REITs risks manifest in the risk of policy and legal, underlying asset, market, operational and credit. The main influencing factors in terms of their weights are tax policy risk, operation and management risk, liquidity risk, termination risk and default risk. The financing project is at a higher risk, and the probability of risk is 64.2%.

This research contributes to the existing body of knowledge by supplementing a set of scientific and practical risk evaluation methods to assess the potential risks of infrastructure REITs project, which contributes the infrastructure financing risk management system. Identify key risk factors for infrastructure REITs with underlying assets, which contributes to infrastructure REITs project management. This research can help relevant stakeholders to control risks throughout the infrastructure investment and financing life cycle, provide them with reference for investment and financing decision-making and promote more sustainable and healthy development of infrastructure REITs in developing countries.

Given the increasing importance of engineering insurance, it is still unclear which specific factors can enhance the role of engineering insurance as a risk transfer tool. This study aims to propose a hybrid approach to identify and analyze the key determinants influencing the consumption of engineering insurance in mainland China.

The empirical analysis utilizes provincial data from mainland China from 2008 to 2019. The research framework is a novel amalgamation of the generalized method of moments (GMM) model, the quantile regression (QR) technique and the random forest (RF) algorithm. This innovative hybrid approach provides a comprehensive exploration of the driving factors while also allowing for an examination across different quantiles of insurance consumption.

The study identifies several driving factors that significantly impact engineering insurance consumption. Income, financial development, inflation, price, risk aversion, market structure and the social security system have a positive and significant influence on engineering insurance consumption. However, urbanization exhibits a negative and significant effect on the consumption of engineering insurance. QR techniques reveal variations in the effects of these driving factors across different levels of engineering insurance consumption.

This study extends the research on insurance consumption to the domain of the engineering business, making theoretical and practical contributions. The findings enrich the knowledge of insurance consumption by identifying the driving factors specific to engineering insurance for the first time. The research framework provides a novel and useful tool for examining the determinants of insurance consumption. Furthermore, the study offers insights into the engineering insurance market and its implications for policymakers and market participants.

This study aims to obtain the mechanistic insights for the fabrication of pure copper thin wall components by selective infrared (IR) laser melting (SLM) and correlated with microstructure development, microhardness, surface morphology and phase analysis. Experimental processes for single track and selection of substrate materials have been studied using a combination of different laser powers and scanning speeds.

SLM of pure copper was performed on a YONGNIAN Laser YLMS-120 SLM machine using an Nd: YAG fiber laser operating at 1,060 nm in the NIR region. Single-track experiments and processing parameters are investigated through different combinations of laser power and scanning speed. The microstructure of the fabricated pure copper samples by SLM technique was analyzed by means of X-ray diffraction, scanning electron microscope equipped with energy disperse spectrometer, optical microscope (OM) and micro-hardness tester.

Steel-based substrates were found suitable for pure copper manufacturing due to sufficient heat accumulation. The width of a single track was determined by liner energy density, showing discontinuities and irregular morphologies at low laser powers and high scanning speeds. As a result of instability of the molten pool induced by Marangoni convection, cracks and cavities were observed to appear along grain boundaries in the microstructure. The top surface morphology of SLM-processed component showed a streamflow structure and irregular shapes. However, the powder particles attached to side surface, which manifest copper powders, are even more sensitive to melt pool of contour track. The crystal phase characteristics of copper components indicated increasing crystallite size of a-Cu, and the decreasing intensity of diffraction peak was attributed to the presence of defects during SLM. The maximum relative density and microhardness were 82 per cent and 61.48 HV0.2, respectively. The minimum thickness of a pure copper thin wall component was 0.2 mm.

This paper demonstrated the forming mechanism and explored feasibility of pure copper thin wall parts by SLM technology in the NIR region. The surface morphology, microstructure and crystal structure were preliminary studied with laser processing parameters.

12Cr2Mo1R(H) steel is commonly used to make hot-wall hydrogenation reactors given its excellent mechanical properties and hydrogen embrittlement (HE) resistance. Longtime exposure to high-pressure hydrogen at medium temperature would still severely damage the mechanical properties of the Cr-Mo steel with surface HICs caused by hydrogen adsorption and hydrogen uptake. The mechanisms of HE remain controversial and have not been fully understood so far.

The HE of the steel was investigated by slow strain rate test at different strain rates with in situ hydrogen charging. The diffusion coefficient of hydrogen in the steel is measured by electrochemical technology of hydrogen permeation. HIC cracks of the fractured specimens were captured with field emission SEM equipped with an electron backscatter diffraction system.

Results showed that the hydrogen led to the plasticity of the samples reduced significantly, together with the distinct work hardening behavior induced by hydrogen charging during plastic flow stage. The fracture of in situ charged sample changes from quasi-cleavage to intergranular fracture with the decreasing of strain rates, which indicates that the steel become more susceptible to hydrogen. High densities of dislocations and deformation are found around the crack, where grains are highly sensitive to HIC. Grains with different Taylor factor are more susceptible to intergranular crack.

The results of the study would be helpful to a safer application of the steel.

The purpose of this paper is to investigate the responsibility that should be taken by different pork supply chain participants to ensure pork quality and safety, with the aim of providing some guidance for strengthening the supervision of pork quality and safety.

The pig farmer survey and the pork consumer survey were conducted in Funing County, Jiangsu Province, using the best-worst scaling (BWS) and a mixed logit model.

The results showed that the designation of responsibility for ensuring pork quality and safety was of, in descending order, feed producers and suppliers, backyard farmers and farms of designated size, pork processing workshops and companies of and above designated size, slaughterhouses, supermarkets, farmer’s markets, pig transporters, and consumers. Both pig farmers and pork consumers believed that those involved in the initial pork supply chain should take greater responsibility for pork quality and safety.

Allocation of responsibilities across the entire pork industry chain was investigated from the perspective of pig farmers and pork consumers using the BWS and a mixed logit model. The results of this study might explain the unique problems that occur in pork supply chain management in large developing countries like China.

This study aims to examine the effect of education for sustainable development (ESD) on students’ sustainability behaviors in Chinese higher education institutions (HEIs), aiming to identify the educational enhancement pathways and influencing factors based on students’ perspectives.

Data were collected from students in Chinese HEIs using an online survey. Structural equation modeling is used to analyze the data and verify the pathways for enhancing students’ sustainability behaviors through ESD in HEIs. The effects of students’ demographic characteristics, majors, and other factors are also examined.

ESD in Chinese HEIs promotes students’ sustainability cognition and behaviors. Students’ sustainability cognition plays a mediating role and has a positive effect on enhancing sustainability behaviors through education. In the influence pathway, the behavioral attitudes of students majoring in humanities and social sciences with high monthly expenditures are more significant for promoting sustainable social participation. Meanwhile, gender and educational level are not significant moderating factors.

Factors such as cognition are subjective and difficult to measure. The sample’s representativeness warrants further consideration, and there is a lack of time-series change data. Nevertheless, this attempt to examine the mechanism of ESD from students’ perspectives can help assess ESD in HEIs more rationally and make the improvement paths more efficient.

This study offers evidence to support ESD-related decision-making in Chinese HEIs. It is suggested that HEIs continue to strengthen ESD, focusing on influencing behavior by enhancing students’ sustainability cognition. Pedagogical approaches should be adjusted based on students’ spending habits and majors to maximize educational outcomes and support China’s sustainability ambitions.

Based on the perspective of Chinese HEI students, this study makes observations about ESD in Chinese HEIs, focuses on the interaction between the sustainability cognition and behaviors of students, and expands the discussion of pathways for HEIs to promote students’ sustainability cognition and behaviors.

Supplier selection for defence procurement is a crucial function of a Ministry of Defence. The Ministry spends huge amounts of money each year to procure a vast array of equipment, goods and services. The ongoing financial crisis demands less subjective and more cost-saving methods for selecting a supplier. The approach advocated in this article integrates Analytic Hierarchy Process (AHP) with Goal Programming (GP) in order to combine conflicting criteria to select the best suppliers and allocate optimum order quantities among them. This paper presents a model close to real-world situations. Findings demonstrate that cost savings is a feasible result along with a viable combination of conflicting criteria in the suppliers' selection area.

With the increasing use of small unmanned aircrafts (SUAs), many countries have enacted laws and regulations to ensure the safe use of SUAs. However, there is a lack of industry-specific regulations accounting for the unique features of construction-related SUA operations. Operating SUAs in the construction industry is attributed to specific risks and challenges, which should be regulated to maximize the utility of SUAs in construction. This study, therefore, aims to develop a multi-dimensional regulatory framework for using SUAs in the construction industry.

A combination of quantitative and qualitative methods was used to compare seven selected national/regional SUA regulations to identify the applicability of implementing the existing regulations in construction. The interview surveys were then conducted to diagnose the challenges of construction-related SUA operations and gather interviewees' suggestions on the regulatory framework for SUA uses in construction.

The research found that some challenges of construction-related SUAs operations were not addressed in the current regulations. These challenges included the complex and time-consuming SUA operation permit, lack of regulation for special SUA operations in construction, insufficient regulatory compliance monitoring and a lack of construction-related remote pilots' training. A regulatory framework was then developed based on the findings of comparative analysis and interview surveys.

This study mainly compared seven representative countries/regions' regulations, leading to a small sample size. Further research should be carried out to study the SUA regulations in other places, such as South Africa, South America or Middle East countries. Besides, this study's respondents to the interviews were primarily concentrated in Hong Kong, which may cause the interview results to differ from the construction industry in other countries/regions. A large-scale interview survey should be conducted in other places in the future to validate the current findings.

The proposed regulatory framework provides a reference for the policy-makers to formulate appropriate industry-specific SUA regulations and improve the applicability of SUA regulations in the construction industry. It sheds light upon the future of SUA regulations and the development of regulatory practice in this area.

This study is the first to propose a multi-dimensional regulatory framework for operating SUAs in construction by comprehensive policy comparisons and interviews. The regulatory framework offers a fresh insight into the unexplored research area and points out the direction for subsequent studies on SUA regulations in the construction industry.