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• A hybrid method that combines the theories of improved CM and a BN is proposed. • The developed method is composed of 13 root factors and 4 s-level factors. • The equipment-related factor is the most significant second-level variable. To effectively evaluate the vulnerability of urban rail transit operations, a hybrid method that combines an improved cloud model and Bayesian network is proposed. This research consists of four parts: evaluation system development, model establishment, result aggregation, and analysis. The developed improved cloud-Bayesian network model is composed of 13 root factors and 4 s-level factors. The Wuhan Metro is adopted as a case study to provide instructions and verify the proposed method. The results indicate the following: (1) Line 2 is the most vulnerable line in the case; (2) The equipment-related factor (D2) is the most significant second-level variable in the vulnerability management of urban rail transit operation; (3) The employee professional level (X2), equipment anti-interference ability (X6), and urban rail transit line density (X11) display high correlations with the corresponding second-level factors; and (4) Peak duration rate (X3), platform passenger density (X4), urban rail transit line density (X11) and disaster seriousness level (X12), especially X4, are considered the key factors when urban rail transit reaches a high vulnerability level. Accordingly, corresponding countermeasures are proposed. The results show that the research conclusion is consistent with the actual situation, and the proposed method can provide a reference for other similar circuits. [ABSTRACT FROM AUTHOR]

Shield construction in karst tunnels inevitably causes settlement deformation and even damage to surrounding buildings. To accurately evaluate the security of neighboring buildings, a hybrid method combining an improved cloud model (CM) and a Bayesian network (BN) is proposed for dynamic security analysis and the evaluation of neighboring buildings. First, through engineering practice, simulation analysis and literature research, the safety risk factors and evaluation criteria for adjacent buildings influenced by shield construction in karst areas are determined, and a BN for safety evaluations of adjacent buildings is constructed. The improved CM is used to model the uncertainty of the risk state, realize the discretization of continuous data and obtain prior knowledge. By improving the cloud Bayesian network (CBN) to perform three kinds of comprehensive analyses, including forward prediction reasoning in advance, sensitivity analysis and reverse risk diagnosis for events, and appropriate risk management and control measures, the dynamic safety perception and control of buildings adjacent to karst shield construction is realized. The data for buildings under construction adjacent to Guiyang Rail Transit Line 3 are used to demonstrate the applicability and effectiveness of the proposed method. The contributions of the research results are as follows: (a) The key risk factors affecting the safety of buildings adjacent to shield construction areas in karst zones are extracted, and an evaluation index system and an evaluation standard are established; (b) An improved CM is used to describe the fuzziness and uncertainty in the process of node state discretization in a risk inference network, thus improving the prediction and diagnosis performance of BN security evaluation models; (c) The improved cloud Bayesian model is applied to construct a knowledge representation-based safety model of buildings adjacent to karst shield construction areas, and accurate perception and control diagnosis results are obtained for effective safety risk prediction and control, providing a reference for other similar projects. [ABSTRACT FROM AUTHOR]

Highlights: [•] We develop a framework of factors to support site planning in urban renewal. [•] We identify factors affecting land-use decision-making in site redevelopment. [•] We incorporate sustainability principles into land-use plans of renewal projects. [•] We review literature on sustainability in site planning and urban renewal. [•] We find the differences of planning considerations between theory and practice. [Copyright &y& Elsevier]

Highlights: [•] Different construction methods influence GHG emissions in the construction phase. [•] A calculation boundary and five emission sources of semi-prefabrication are set. [•] A quantitative model of GHG emissions of semi-prefabrication is established. [•] Two cases with different construction methods are employed for preliminary comparison of the differences in GHG emissions. [•] Adopting prefabrication may contribute significant environmental benefits on GHG emissions. [Copyright &y& Elsevier]

Abstract: Urban renewal is a significant issue in developed urban areas, with a particular problem for urban planners being redevelopment of land to meet demand whilst ensuring compatibility with existing land use. This paper presents a geographic information systems (GIS)-based decision support tool (called LUDS) to quantitatively assess land-use suitability for site redevelopment in urban renewal areas. This consists of a model for the suitability analysis and an affiliated land-information database for residential, commercial, industrial, G/I/C (government/institution/community) and open space land uses. Development has occurred with support from interviews with industry experts, focus group meetings and an experimental trial, combined with several advanced techniques and tools, including GIS data processing and spatial analysis, multi-criterion analysis, as well as the AHP method for constructing the model and database. As demonstrated in the trial, LUDS assists planners in making land-use decisions and supports the planning process in assessing urban land-use suitability for site redevelopment. Moreover, it facilitates public consultation (participatory planning) by providing stakeholders with an explicit understanding of planners'' views. [Copyright &y& Elsevier]

Abstract: The construction of buildings has a very important impact on the environment, and the process of manufacturing and transporting of building materials, and installing and constructing of buildings consumes great energy and emits large quantity of greenhouse gas (GHG). The present paper defines four sources of GHG emissions in building construction, which are: manufacture and transportation of building materials; energy consumption of construction equipment; energy consumption for processing resources; and disposal of construction waste, and then establishes the calculation method of GHG emissions. This paper presents a case study of GHG emissions in building construction in Hong Kong. The results show that 82–87% of the total GHG emissions are from the embodied GHG emissions of building materials, 6–8% are from the transportation of building materials, and 6–9% are due to the energy consumption of construction equipment. The results also indicate that embodied GHG emissions of concrete and reinforced steel account for 94–95% of those of all building materials, and thus the use of recycled building materials, especially reinforced steel, would decrease the GHG emissions by a considerable amount. [Copyright &y& Elsevier]

Abstract: This paper applies a system dynamics model for the sustainable land use and urban development in Hong Kong. The model is used to test the outcomes of development policy scenarios and make forecasts. It consists of five sub-systems including population, economy, housing, transport and urban/developed land, respectively. Two distinctively different development schemes concerning urban population density are simulated by the model and the findings are undertaken to verify the model through comparison with historical data and sensitivity check. The forecast timeframe is then expanded from 40 years to 300 years, providing a simulation period long enough to observe and study the “limits to growth” phenomenon and the impacts on development potential of Hong Kong. The modelling results are directly useful to compare different dynamic consequences brought by various policies and decisions, and are thus of great significance to achieving the goal of sustainable land use. [Copyright &y& Elsevier]

Problem: Bamboo scaffolding has been widely used in South China, Hong Kong, and Southeast Asia for many years. Bamboo scaffolding is more economical, but its safety record is relatively poor. Conversely, metal scaffolding is more expensive, but its use in these regions has increased in recent years because it is relatively safe. The assessment and selection of the most appropriate type of scaffolding for a particular construction project is always a concern for project managers. Method: This paper suggests a comprehensive assessment framework that enables project managers to take a number of major quantitative and qualitative factors into consideration when making scaffolding decisions. This framework is based on the Analytic Hierarchy Process methodology and a survey among project managers in Hong Kong. Results: The research reveals that the overall performance of metal scaffolding is believed to be better than bamboo scaffolding. A sensitivity analysis has also been conducted to investigate the impact of various factors on the final decisions. Impact on Industry: The proposed assessment framework can be used as a supporting tool for project managers in the selection of scaffolding for their projects. [Copyright &y& Elsevier]

To reduce the impact of tunnel construction on adjacent bridge pile foundations and ensure safety during construction, a hybrid intelligent framework combining Bayesian optimization (BO), categorical boosting (CatBoost), and the nondominated sorting genetic algorithm-III (NSGA-III) is proposed in this paper. The nonlinear mapping function relationship between the nine input parameters and the bridge pier vertical and horizontal displacements is established via BO-CatBoost. The key optimization parameters are for interpretability analysis and determined via Shapley additive explanations (SHAP) method. NSGA-III is established with the goal of minimizing pier displacement. The applicability and validity of the proposed method are tested in a case study of the Wuhan Metro. The key findings of this study include the following. (1) The accuracy of the prediction model obtained by the BO-CatBoost algorithm on the basis of the training and simulation of the measured engineering data is high. On the bridge pier horizontal and vertical displacement test sets, the R2 values are 0.823 and 0.826, the RMSE values are 0.452 and 0.539, and the MAEs are 0.293 and 0.360, respectively. (2) The optimization effect of the two objectives is significant, and the average percentage of improvement stands at 35.54%. When five shield construction parameters are adjusted simultaneously, the optimization effect of the two objectives is the best, and the average improvement percentage is 54.76%. (3) The optimization effect of the developed BO-CatBoost-NSGA-III intelligent algorithm is greater than that of single-objective optimization. Therefore, the intelligent optimization framework proposed in this paper can provide guidance for the optimal control of pier displacement in shield underpass construction engineering. [ABSTRACT FROM AUTHOR]

Given its small chip area and high current density, the fault protection of SiC MOSFET is a serious challenge. In this paper, a gate voltage-based fault protection method for a SiC MOSFET subjected to short circuit type II also called fault under load is proposed. The circuit implementation of the proposed method is analyzed in detail. A test with a voltage of 200 V is conducted. Experimental results verify the effectiveness of the proposed method. It is exhibited the fault response time of the proposed method is less than 1 μs, which is very fast to protect a device and is conducive to the reliable and safe operation of SiC MOSFETs. [ABSTRACT FROM AUTHOR]

Given the leading role of the construction industry in fossil fuel consumption, it is essential to identify the drivers responsible for carbon emission in that sector. Based on the panel data of 30 provinces in China in the period between 2000 and 2015, this study estimated the spatial distribution and driving innovation factors of construction carbon emissions (CCE) by using Moran's I index and spatial econometric models as underlying methods. The empirical results show that there were significant spatial dependence and clustering characteristics in provincial CCE. The net value of machinery and equipment, labor productivity, technical renovation input, construction gross domestic product, and the total construction profit prohibit greater emission reductions. Specifically, the economy related performance indicators cause smaller positive impacts on emission growth than the machinery- and labor-related factors. In addition, it is also noted that proportion of technical personnel and the ratio of technical equipment have significantly positive effects on CCE abatement. The findings of this study would be beneficial for local government to adopt stratified and effective emission reduction methods in the provincial construction industry. • The distribution of the provincial CCE showed remarkable spatial disparities. • The influence of surrounding regions was positive on CCE reduction of specific regions. • Economy related performance indicators cause small positive impacts on emission growth. • This study revealed the status quo of low technology innovation in construction industry. [ABSTRACT FROM AUTHOR]

Since the housing marketization reform, China's real estate industry has rapidly developed and commercial housing prices have risen sharply. The main reason for this is the speculative demand for housing, which breaks the equilibrium of supply and demand, leading to housing prices deviating from their basic value. The housing market in China is not isolated by province, since speculative behavior in one part of the country can affect other regions. This paper analyzes the spatial relevance in housing prices among different provinces in China by calculating Moran's I index and by measuring the speculation degree through spatial autoregressive model (SAR), a spatial economic model combined with a spatial weight matrix. For commercial housing speculation degree measurement and comparison, 31 provinces in China were chosen along with the following variables: housing prices, personal disposable income, one-year personal housing mortgage rates, housing prices growing rates, the rent, amount of residential investment, and the construction areas of houses. The results show that China's housing prices have a clear interaction among the selected cities, and that housing speculation behavior also influences each other in space. Although there are speculation activities in China, from a global perspective the degree of speculation, which varies from region to region, is still just within internationally acceptable limits. Although there are some regions with high degrees of housing speculation, the speculation is not yet China-wide. [ABSTRACT FROM AUTHOR]

The rapid urbanization in China has produced a large demand for energy in the past decades. It is therefore urgent to have an understanding of the driving forces behind the energy increase in the construction industry. This study applies structural decomposition analysis (SDA) to quantify the effects of driving factors from insight into consumption and production. The results show that the energy consumption trajectory of China's construction industry is the result of competition between the effect of increasing final demand and improvement in energy efficiency. Although the effect of consistent efforts in structure optimization by the central government was significant from 2007 to 2012, the potential to save much energy still lies in structure optimization in energy, production, and final demand. According to the projection, structural upgrades in economy would be the most important factor for energy reduction in 2020. Scenario analysis further indicated that the percentage change of energy increments in 2020 can be reduced at 22% of 2010 level under the optimistic scenario. Sector aggregation analysis revealed that more aggregates would increase uncertainty to some extent and result in a misinterpretation of the importance of the underlying factors. According to the quantitative analysis in this study, the percentage change of total embodied energy consumption in the construction industry should be limited below 25% of 2010 level at the end of the 13th Five-Year Plan. [ABSTRACT FROM AUTHOR]

Although sustainable development in the construction industry has attracted much attention, relevant studies on the regional scale analysis of industrial energy performance are still rare in China, especially for Guangdong province, which is currently on the frontier and fast track of national low-carbon development. In response, this study integrates a multi-regional input-output method with field-based operational data to quantify the total embodied energy consumption and energy transfers from the construction industry and assess the life cycle energy use of residential and office buildings in Guangdong Province. The results show that the embodied energy consumption of the provincial construction industry is localization dominant and fossil fuel oriented, which accounts for approximately 18.6% of the total regional energy consumption. The geographical connection and resource characteristic are the two factors that influence the interregional energy transmissions induced by construction activities in Guangdong province. The result of uncertainty analysis indicates that the mean value of energy intensities simulated by Monte Carlo simulation is highly consistent with the deterministic results. It is crucial to improve the accuracy of the input-output analysis by providing sufficient economic information. At last, a number of recommendations are given through the technology, product, and management aspects at the industrial and building levels. The local government and construction department can benefit from implementing such environment-friendly, technology innovative and multi-disciplinary solutions in the full-process management and improvement of energy reduction of buildings. [ABSTRACT FROM AUTHOR]

Abstract: Since China's economic reforms began in 1978, rural–urban migration has accelerated urban growth and the consequential need for regional planning. In order to make effective strategic decisions on regional planning, it is essential to identify the determinants that promote or restrain urban growth. Based on the theoretical underpinnings of classical economics, spatial economics and sustainable development, this paper establishes a theoretical model of urban population growth and uses a case study of China's Guangdong Province to test a hypothesis. The driving force of urban population growth is derived from natural and mechanical increases that include original urban size, living environment, industrial agglomeration, and location. Regression results from the case study reveal that during the period 2000–2010, factor of dominant industry significantly and consistently impacted urban growth, whereas the influence of living conditions and location on urban growth varied from year to year. These findings imply that local government pays less attention to residents' livelihood and more to the effect of location on urban growth. The paper concludes by proposing some regional planning policies for sustainable development. [Copyright &y& Elsevier]

Hong Kong is an international metropolis with a highly dense population. As a result, it faces enormous challenges in terms of land supply. As part of the Hong Kong Government's initiative to increase land supply, the Civil Engineering and Development Department (CEDD) proposed minor relaxation of the maximum plot ratio/building height restrictions for 21 target sites in Kai Tak Development Area (KTDA). Although CEDD has explored the feasibility of increasing development intensity by assessing environmental impacts, infrastructure capacity and public consultation, these reviews and assessments were conducted based on the 2D GIS. Since the spatial distribution of land unit in the real world is three-dimensional, 3D GIS can help us look into the world in true perspective and make informed decisions. This study aims to investigate the viability of minor relaxation of maximum plot ratio/building height restrictions of 21 sites in KTDA through 3D modeling and 3D spatial analyses, including skyline, visual impact, shadow and solar exposure. Regarding to the 21 target sites, four scenarios with different plot ratios and building heights were built and compared. The results indicate that minor relaxation of maximum plot ratio and building height leads to (i) minor effect on skyline (ii) minor effect on visual impact and (iii) slight changes in shadow and solar exposure both in winter and summer. Therefore, in light of the findings from this study, scenario 4 is the recommended reasonable scale to relax the maximum plot ratio/building height restriction for the target sites in KTDA. Besides, this study can also be applied in the urban renewal studies and other new development areas in Hong Kong, or even in other densely populated cities. [ABSTRACT FROM AUTHOR]

Abstract: Construction dust is one of the most concerned pollutants presenting risks to human health. Dust generated from concrete drilling, particularly true for silica dust, have an adverse effect on the health of workers. There is a long-term concern about the overexposure of construction workers to respirable crystalline silica. The high exposure to silica, even over a short period, can lead to silicosis. In order to control the dust generated during the process of concrete drilling, a local Hong Kong contractor has implemented DustBubble during the concrete drilling works. In order to evaluate the effectiveness of this new dust control measure, an experimental study has been designed and conducted. The respirable dust and silica dust concentrations of the following two situations were compared: workers drilling concrete with and without the use of DustBubble. Personal respirable samples were collected and analysed based on NIOSH 0600 and 7500 methods. The results revealed that DustBubble could significantly reduce the respirable dust exposure by 63%. However, there was no evidence that the use of DustBubble could reduce the respirable quartz exposure. [Copyright &y& Elsevier]

China has exhibited an active attitude with regard to abating global climate change. To analyze the effect of economy development and urbanization quality on interregional energy transmissions against a backdrop of new-type urbanization, this study integrated MRIO model, complex network method, and spatial autocorrelation analysis to systematically analyze the spatiality and spillover effects of interregional energy connections. The results show that the interregional energy connectivity was spatially dependent whilst urban-rural income ratios and population structures were statistically significant in the national-level spatial econometric analysis. Specifically, a regional-level spatial regression analysis demonstrated that population structure, education level, the energy connectivity of other regions, and the income-expenditure ratios of other regions were four determinants that were significant in eastern, central, and western areas. Structural optimization is a key direction for future energy reduction nationwide. This study shed light on the current spillover effects of energy connective intensity, which is beneficial for making stratified and fair energy reduction policies at the regional level. • Explore the impact of urbanization quality on interregional energy transmissions. • Reveal the spatiality and spillover effects of interregional energy connections. • Identify the determinants for energy reduction nationwide. [ABSTRACT FROM AUTHOR]