Tightly-Coupled Vehicle Positioning Method at Intersections Aided by UWB

Reliable and precise vehicle positioning is essential for most intelligent transportation applications as well as autonomous driving. Due to satellite signal blocking, it can be challenging to achieve continuous lane-level positioning in GPS-denied environments such as urban canyons and crossroads. In this paper, a positioning strategy utilizing ultra-wide band (UWB) and low-cost onboard sensors is proposed, aimed at tracking vehicles in typical urban scenarios (such as intersections). UWB tech offers the potential of achieving high ranging accuracy through its ability to resolve multipath and penetrate obstacles. However, not line of sight (NLOS) propagation still has a high occurrence in intricate urban intersections and may significantly deteriorate positioning accuracy. Hence, we present an autoregressive integrated moving average (ARIMA) model to first address the NLOS problem. Then, we propose a tightly-coupled multi sensor fusion algorithm, in which the fuzzy calibration logic (FCL) is designed and introduced to adaptively adjust the dependence on each received UWB measurement to effectively mitigate NLOS and multipath interferences. At last, the proposed strategy is evaluated through experiments. Ground test results validate that this low-cost approach has the potential to achieve accurate, reliable and continuous localization, regardless of the GPS working statue

Analysis of Factors Influencing the Job Satisfaction of New Generation of Construction Workers in China: A Study Based on DEMATEL and ISM

China’s construction industry is facing serious problems of aging construction workers and labor shortages. Improving the job satisfaction of construction workers is a key point for retaining existing construction workers and for attracting younger generations into the construction field in China. At present, the new generation of construction workers (NGCW) born after 1980 has been the main force on construction sites in China. Therefore, it is very important to study and explore the influencing factors of the job satisfaction of the NGCW. This paper aims to determine the influencing factors of job satisfaction of the NGCW through literature research and to clarify the interaction mechanisms and hierarchical structures of influencing factors using the Decision-Making Trial and Evaluation Laboratory (DEMATEL) and Interpretive Structural Modeling (ISM) to design appropriate human resource practices to promote their job satisfaction. Research findings show that there are 12 main influencing factors of job satisfaction of the NGCW, which are at three levels: personal traits, job characteristics and social environment, and the influencing factors can be divided into a cause group and an effect group, including four layers: the root layer, controllable layer, key layer and direct layer in the multi-level hierarchical structure model. Furthermore, the critical influencing factors of the job satisfaction of the NGCW consist of education level, competency, career development, salaries and rewards, rights protection and work–family balance. This research enriches the job satisfaction literature of construction workers and provides an important reference for decision makers in construction enterprises and the construction industry to understand what influences the job satisfaction of the NGCW and how it is influenced to then improve it in China

Mineralogical and Geochemical Characteristics of Carbonates and Their Geological Significance to the Fuli Pb-Zn Deposit, Yunnan Province

Mississippi Valley-Type (MVT) deposits are among the main types of Pb-Zn deposits that feature carbonate minerals as the main gangue minerals; their formation runs through the entire metallogenic process of MVT deposits. Therefore, carbonate minerals contain rich information on metallogenic fluid evolution and are thus important prospecting indicators. The Fuli Pb-Zn deposit in eastern Yunnan is located in the southeast of the Sichuan-Yunnan-Guizhou (SYG) Pb-Zn metallogenic province, which is the biggest producer of zinc and lead in China and contains more than 400 deposits and over 20 million tons of Pb + Zn reserves. The ore occurs in the interlayer fracture zone of Middle Permian Yangxin Formation Dolomite, and the orebody shape is generally stratiform. The main metal-bearing minerals of this deposit are sphalerite, galena, and pyrite; the gangue minerals mainly comprise dolomite and calcite. Three mineralized stages are observed (the early metallogenic period, the main metallogenic period, and the late metallogenic period) according to the characteristics of stratigraphic output, the intercalated contact relationship of gangue minerals, and the alteration characteristics of the wall rock. To determine the source and properties of the ore-forming fluid and the ore-forming process of the Fuli Pb-Zn deposit, different stages of mineralogy and trace element geochemical characteristics of hydrothermal dolomite were systematically studied. The minerals were observed under microscope and subjected to in situ analysis by LA-ICP-MS and C–O isotope test. The δ18OSMOW value of the dolomite in the metallogenic period was between 13.29‰ and 20.55‰, and the δ13CPDB value was between −4.13‰ and 3.5‰. Dolomite of the metallogenic period mainly came from the dissolution of carbonate wall rocks, while C in the ore-forming fluid came from the wall rocks. A few dolomites showed a trend of depleting δ13CPDB and δ18OSMOW at the same time, implying the influence of sedimentary rock contamination in the mantle multiphase system. The lower δ18O was due to the exchange of O isotopes between the wall rocks and the depleted δ18O in ore-forming fluids. From the early to the later stage of mineralization, the ore-forming fluid changed from alkaline to neutral to weakly acidic due to a decrease in the oxygen fugacity and temperature of the fluid; this change resulted in the precipitation of sulfide and dolomite in the deposit. From the early to the late stages of mineralization, Fe and Mn showed a downward trend. Fe and Mn entered the alkaline environment of the carbonate minerals, while Fe and Mn were released into the acidic fluid, indicating that due to the metasomatism from strong to weak, their metallogenic environment evolved from alkaline to acidic. From the early to the late stage of mineralization, Sr showed an upward trend, which might indicate that the continuous reaction between the hydrothermal fluid and the wall rock continuously released Sr into the fluid. The Fe-Sr and Mn-Sr diagrams show that two kinds of fluid mixing occurred in the ore-forming process. The Fuli Pb-Zn deposit may have formed from mineral precipitation caused by the mixing of the metal-rich, oxidized acidic fluid and the sulfur-rich, reduced alkaline fluid. The results show that the Fuli Pb-Zn deposit belongs to MVT deposits

Geochemistry, Zircon U-Pb Geochronology and Lu-Hf Isotopic Composition of Eclogites and Their Host Gneisses in the Dulan Area, North Qaidam UHP terrane: New Evidence for Deep Continental Subduction

In this study, we link zircon U-Pb SHRIMP and LA-ICP-MS geochronology and the Lu-Hf isotopic composition of eclogites and their host gneisses/schists with whole-rock geochemistry of eclogites in the Dulan area to constrain their protoliths and metamorphic relationships. U-Pb dating suggests that the protolith of one of the eclogites was a Neoproterozoic mafic intrusive rock (828 ± 58 Ma) and the protolith of enclosing orthogneiss was an early-Neoproterozoic granitoid (923 ± 12 Ma). Detrital zircons from Grt-bearing mica-schists yield ages of 0.9–2.5 Ga, with a dominant range of 1.0–1.8 Ga, indicating sedimentary sources from Neoproterozoic to Neoarchean crust and a depositional age ≤ 0.9 Ga. The matching metamorphic ages of eclogites (438 ± 5 Ma, 436 ± 4 Ma) and their country rocks (Grt-bearing mica-schists: 438 ± 4 Ma, 439 ± 8 Ma; orthogneiss: 427 ± 8 Ma) indicate that all studied samples experienced coeval Early Paleozoic HP/UHP metamorphism. The U-Pb ages and Hf isotopic compositions of the inherited magmatic zircon cores of an eclogite sample (εHf (800) = 2.6–9.2, TDM1 = 1.0–1.3 Ga, TDM2 = 1.1–1.4 Ga) suggest that the protolith may be derived from Neoproterozoic depleted mantle with variable proportions of an older crustal component. The magmatic zircon cores of the orthogneiss (εHf (900) = − 7.3 to − 0.2; TDM2 = 1.8–2.1 Ga) suggest that the parental magma was derived from a Paleoproterozoic crustal source. Hf isotopic compositions of the detrital zircons from the metasediments (εHf(t) = − 19.4 to + 10.6) suggest three crust formation and reworking events: (1) Archean (TDM2 = 2.7–2.9 Ga) juvenile crust reworked at ~ 2.5 Ga; (2) early Paleoproterozoic (TDM2 = 2.3–2.5 Ga) juvenile crust reworked at ~ 1.8 Ga; and (3) late Paleoproterozoic (TDM2 = 1.5–1.9 Ga) juvenile crust reworked in the Neoproterozoic. Whole-rock geochemical data suggest that the protoliths of the Dulan eclogites were probably derived from a continental rift or an incipient oceanic basin rather than a large, long-lived ocean basin. Thus, combined with field relationships, petrology, geochemistry, zircon U-Pb dating and the Lu-Hf isotopic analysis presented in this paper and reported from previous studies, we suggest that the Dulan eclogites and their country rocks experienced a common UHP metamorphism during Late Ordovician deep continental subduction

FDNet: An end-to-end fusion decomposition network for infrared and visible images.

Infrared and visible image fusion can generate a fusion image with clear texture and prominent goals under extreme conditions. This capability is important for all-day climate detection and other tasks. However, most existing fusion methods for extracting features from infrared and visible images are based on convolutional neural networks (CNNs). These methods often fail to make full use of the salient objects and texture features in the raw image, leading to problems such as insufficient texture details and low contrast in the fused images. To this end, we propose an unsupervised end-to-end Fusion Decomposition Network (FDNet) for infrared and visible image fusion. Firstly, we construct a fusion network that extracts gradient and intensity information from raw images, using multi-scale layers, depthwise separable convolution, and improved convolution block attention module (I-CBAM). Secondly, as the FDNet network is based on the gradient and intensity information of the image for feature extraction, gradient and intensity loss are designed accordingly. Intensity loss adopts the improved Frobenius norm to adjust the weighing values between the fused image and the two raw to select more effective information. The gradient loss introduces an adaptive weight block that determines the optimized objective based on the richness of texture information at the pixel scale, ultimately guiding the fused image to generate more abundant texture information. Finally, we design a single and dual channel convolutional layer decomposition network, which keeps the decomposed image as possible with the input raw image, forcing the fused image to contain richer detail information. Compared with various other representative image fusion methods, our proposed method not only has good subjective vision, but also achieves advanced fusion performance in objective evaluation

Influence Mechanism of Organizational Flexibility on Enterprise Competitiveness: The Mediating Role of Organizational Innovation

Organizational success heavily relies on the competitiveness of products and services under rapidly changing market conditions. This enterprise competitiveness becomes more critical for project-based enterprises as modernization of the Chinese construction industry creates greater challenges and uncertainty in construction operations, which determines the sustainable advantages of enterprises to a certain degree. Traditional wisdom focuses on cost efficiency, asset differentiation, and service performance to gain competitive advantages. This paper explores the influence of organizational flexibility and organizational innovation on enterprise competitiveness for Chinese construction organizations. A designed structured questionnaire was developed and conducted targeting the project-based enterprises in China’s construction industry and is accompanied by a structural equation modeling analysis. Results indicate a positive impact of organizational flexibility on enterprise competitiveness along with a mediation role of organizational innovation. The study concludes that new organizational strategies are required for Chinese project-based enterprises to maintain enterprise competitiveness in order to realize the sustainable development of enterprises

Influencing Mechanism of Job Satisfaction on Safety Behavior of New Generation of Construction Workers Based on Chinese Context: The Mediating Roles of Work Engagement and Safety Knowledge Sharing

China’s construction industry developed rapidly and safety production has become a vital issue. Improving the safety behavior of construction workers is an important measure to effectively decrease construction safety accidents. At present, a New Generation of Construction Workers (NGCWs) born after 1980 has gradually become the main force of construction companies in China and the special group characteristics coming from the intergenerational difference may make them behave differently in safety-related activities, therefore, it is very important to study how to promote their safety behavior. This paper aimed to explore the influencing mechanism of job satisfaction on the safety behavior of NGCWs and examine the mediating role of safety knowledge sharing and work engagement. Confirmatory factor analysis and structural equation modeling analysis were applied to test the theoretical model. Empirical research results indicated that job satisfaction can effectively promote safety behavior through safety knowledge sharing and work engagement. Safety knowledge sharing plays a complete mediating role between job satisfaction and safety compliance behavior, as well as between job satisfaction and safety participation behavior. Moreover, work engagement plays a complete mediating role between job satisfaction and safety participation behavior, which can provide valuable management references for China’s construction companies to strengthen their safety behavior