An analysis of coupling coordination relationship between regional economy and transportation: empirical evidence from China.

The increasing discrepancy between a regional economy and transportation imposes higher requirements for their coordinated development. This paper utilized the coupling coordination degree (CCD) model and entropy method (EM) to quantitatively study the coupling coordination state between regional economy and transportation and its spatial distribution of 30 provinces in China from 2004 to 2017. The results show the following: (1) The comprehensive level of regional economy and transportation development in China has shown a growing trend, and the development of regional economy is faster than that of the transportation. (2) The CCD between regional economy and transportation in China is changing from incoordination to high-level coordination. The imbalance of CCD levels among the regions studied varies significantly. The CCD in the eastern regions is slightly higher than that in the central, western, and northeast regions. (3) In the region with a higher CCD, the discrepancy between the development of regional economy and transportation is higher than that in other regions. Moreover, suggestions are provided to promote the coordinated development from a regional perspective. This study provides references to policymakers to help them properly plan and design transportation systems while considering the regional economy, thus stimulating the coordinated and sustainable development between regional economy and transportation.

A Feasibility Study on HPMC-Improved Sulphoaluminate Cement for 3D Printing.

A novel 3D printing material based on hydroxypropyl methylcellulose (HPMC)-improved sulphoaluminate cement (SAC) for rapid 3D construction printing application is reported. The hydration heat, setting time, fluidity of paste and mortar, shape retainability, and compressive strength of extruded SAC mortar were investigated. HPMC dosage, water-to-cement (W/C) ratio, and sand-to-cement (S/C) ratio were studied as the experimental parameters. Hydration heat results reveal HPMC could delay the hydration of SAC. The initial and final setting time measured using Vicat needle would be shortened in the case of W/C ratio of 0.3 and 0.35 with HPMC dosage from 0.5% to 1.5%, W/C ratio of 0.40 with HPMC dosage of 0.5%, 0.75%, and 1.5%, and W/C ratio of 0.45 with HPMC dosage of 0.45, or be extended in the case of W/C ratio of 0.4 with HPMC dosage of 1.0% and W/C ratio of 0.45 with HPMC dosage from 0.75% to 1.5%. Fluidity measurement shows HPMC significantly improves the shape retainability. Furthermore, the addition of HPMC remarkably increased the compressive strength of extruded mortar. The results showed that HPMC could be used to prepare 3D printing SAC having satisfactory shape retainability, setting time and compressive strength.

Critical factors and paths influencing construction workers' safety risk tolerances.

While workers' safety risk tolerances have been regarded as a main reason for their unsafe behaviors, little is known about why different people have different risk tolerances even when confronting the same situation. The aim of this research is to identify the critical factors and paths that influence workers' safety risk tolerance and to explore how they contribute to accident causal model from a system thinking perceptive. A number of methods were carried out to analyze the data collected through interviews and questionnaire surveys. In the first and second steps of the research, factor identification, factor ranking and factor analysis were carried out, and the results show that workers' safety risk tolerance can be influenced by four groups of factors, namely: (1) personal subjective perception; (2) work knowledge and experiences; (3) work characteristics; and (4) safety management. In the third step of the research, hypothetical influencing path model was developed and tested by using structural equation modeling (SEM). It is found that the effects of external factors (safety management and work characteristics) on risk tolerance are larger than that of internal factors (personal subjective perception and work knowledge & experiences). Specifically, safety management contributes the most to workers' safety risk tolerance through its direct effect and indirect effect; while personal subjective perception comes the second and can act as an intermedia for work characteristics. This research provides an in-depth insight of workers' unsafe behaviors by depicting the contributing factors as shown in the accident causal model developed in this research.