51 research outputs found

    DavarOCR: A Toolbox for OCR and Multi-Modal Document Understanding

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    This paper presents DavarOCR, an open-source toolbox for OCR and document understanding tasks. DavarOCR currently implements 19 advanced algorithms, covering 9 different task forms. DavarOCR provides detailed usage instructions and the trained models for each algorithm. Compared with the previous opensource OCR toolbox, DavarOCR has relatively more complete support for the sub-tasks of the cutting-edge technology of document understanding. In order to promote the development and application of OCR technology in academia and industry, we pay more attention to the use of modules that different sub-domains of technology can share. DavarOCR is publicly released at https://github.com/hikopensource/Davar-Lab-OCR.Comment: Short paper, Accept by ACM MM202

    Research on Local Government Governance and Enterprise Social Responsibility Behaviors under the Perspective of Cournot Duopoly Competition: Analyzing Taxi Companies and Online Car-Hailing Service Companies

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    Clarifying the rational choice strategy of local governments and enterprises is crucial for promoting control on the failure of taxis and online car-hailing service companies to fulfill their social responsibilities. The local government can reduce the negative externalities and irresponsibility of such companies by improving the regulatory system; thus, it is important to build a governance model that bridges tradition and modernity. This paper, on the basis of summarizing the achievements of the predecessors, builds a mixed dynamic game model among the local government, online car-hailing service companies, and taxi companies; analyzes the relationship between local government preference, execution, and governance of irresponsible enterprise behaviors; and analyzes the equilibrium solution between local government and duopoly enterprises behavior game deeply. The results show that the key to governance irresponsible companies is to make the punishment cost higher than the cost savings for irresponsible behaviors; no matter what the preference of the local government no-governance of online car-hailing service companies’ irresponsible behaviors may persist; and local government ambivalence when regulating irresponsible companies is derived from the complex relationship between social benefits and company interests. Finally, through the analysis of the equilibrium results for the above model, this paper provides suggestions on regulatory policies so as to provide theoretical support and a decision-making basis for establishing scientific, universal, and feasible governance policies and offering responsible methods of urban transportation

    Flame-Retardant Performance of Transparent and Tensile-Strength-Enhanced Epoxy Resins

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    In this study, a flame-retardant additive with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) groups denoted DSD was successfully synthesized from DOPO, 4,4′-diaminodiphenyl sulfone (DDS), and salicylaldehyde. The chemical structure of DSD was characterized by FTIR–ATR, NMR, and elemental analysis. DSD was used as an amine curing agent, and the transparent, tensile strength-enhanced epoxy resins named EP–DSD were prepared via thermal curing reactions among the diglycidyl ether of bisphenol A (DGEBA), 4,4′-diaminodiphenylmethane (DDM), and DSD. The flame-retardancy of composites was studied by the limiting oxygen index (LOI) and UL-94 test. The LOI values of EP–DSD composites increased from 30.7% for a content of 3 wt % to 35.4% for a content of 9 wt %. When the content of DSD reached 6 wt %, a V-0 rating under the UL-94 vertical test was achieved. SEM photographs of char residues after the UL-94 test indicate that an intumescent and tight char layer with a porous structure inside was formed. The TGA results revealed that EP–DSD thermosets decomposed ahead of time. The graphitization degree of the residual chars was also investigated by laser Raman spectroscopy. The measurement of tensile strength at breaking point shows that the loading of DSD increases the tensile strength of epoxy thermosets. Py-GC/MS analysis shows the presence of phosphorus fragments released during EP–DSD thermal decomposition, which could act as free radical inhibitors in the gas phase. Owing to the promotion of the formation of intumescent and compact char residues in the condensed phase and nonflammable phosphorus fragments formed from the decomposition of DOPO groups, EP–DSD composites displayed obvious flame-retardancy

    The Effects of Urban Sprawl and Industrial Agglomeration on Environmental Efficiency: Evidence from the Beijing–Tianjin–Hebei Urban Agglomeration

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    Environmental efficiency evaluation is an effective way to assess the synergetic development degree between the economy and environment. In order to realize the mechanism of the effects of urban sprawl and industrial agglomeration on environmental efficiency by using the super efficiency Slacks-based Measure (SBM) model with undesirable outputs, this paper firstly calculates the environmental efficiency of the 13 cities in the Beijing−Tianjin−Hebei urban agglomeration from 2006 to 2017. Then, based on the panel data of the 13 cities, we empirically examine the influence of urban sprawl and industrial agglomeration on environmental efficiency by adopting the panel Tobit regression model. The results show that large gaps exist in the degree of the cities’ environmental efficiency in the research period, and only Beijing’s environmental efficiency exhibits full efficiency in the 13 cities, with the overall environmental efficiency of the Beijing−Tianjin−Hebei urban agglomeration presenting a decreasing trend. Additionally, the Tobit regression results indicate that urban sprawl has a significantly negative impact on environmental efficiency, but with the continual improvement of industrial agglomeration, the negative effects of urban sprawl will be partially offset. From the regression results of control variables, economic growth and urbanization developments have an inhibiting effect on the promotion of environmental efficiency. Furthermore, industrial structure optimization and technological innovation are helpful to improve environmental efficiency. The opening-up policy has had a significantly positive impact on environmental efficiency, and the “pollution paradise” hypothesis was untenable in the Beijing−Tianjin−Hebei urban agglomeration

    Research on the Spatial Network Characteristics and Synergetic Abatement Effect of the Carbon Emissions in Beijing–Tianjin–Hebei Urban Agglomeration

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    Based on the carbon emission data in the Beijing–Tianjin–Hebei urban agglomeration from 2007 to 2016, this paper used the method of social network analysis (SNA) to investigate the spatial correlation network structure of the carbon emission. Then, by constructing the synergetic abatement effect model, we calculated the synergetic abatement effect in the cities and we empirically examined the influence of the spatial network characteristics on the synergetic abatement effect. The results show that the network density first increased from 0.205 in 2007 to 0.263 in 2014 and then decreased to 0.205 in 2016; the network hierarchy fluctuated around 0.710, and the minimum value of the network efficiency was 0.561, which indicates that the network hierarchy structure is stern and the network has good stability. Beijing and Tianjin are in the center of the carbon emission spatial network and play important “intermediary” and “bridge” roles that can have better control over other carbon emission spatial spillover relations between the cities, thus the spatial network of carbon emissions presents a typical “center–periphery” structure. The synergetic abatement effect increased from −2.449 in 2007 to 0.800 in 2011 and then decreased to −1.653 in 2016; the average synergetic effect was −0.550. This means that the overall synergetic level has a lot of room to grow. The carbon emission spatial network has a significant influence on the synergetic abatement effect, while increasing the network density and the network hierarchy. Decreasing the network efficiency will significantly enhance the synergetic abatement effect

    3D Modeling of Mine Protection Complex Steel Structure Based on BIM Technology

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    The objective of this paper is to study the antidamage ability of beam column joints in complex steel structures under external forces and to improve the safety of such structures. In this study, a three-dimensional model of complex steel structure based on BIM technology is proposed by analyzing and calculating the ultimate strength of complex steel structure for mine protection. The vibration control algorithm of complex steel structure for mine protection is designed, and the boundary elastic constraint conditions are determined. According to the constraint conditions, the vibration characteristics of complex steel structures for mining are analyzed. The experimental results show that the maximum displacement of the design model is reduced by half compared with that before optimization, which can meet the design requirements

    Stability analysis and control technology of gob-side entry retaining with double roadways by filling with high-water material in gently inclined coal seam

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    To ameliorate the defects of insufficient support resistance of traditional roadside filling bodies for gob-side entry retaining (GER), overcome the inability to adapt to the deformation of surrounding rock, and isolate the goaf effectively, a new type of high-water material as a roadside filling body for GER technology with double roadways was proposed. The instability analysis and control technology of GER with double roadways by filling high-water material into a gently inclined coal seam were studied. The basic mechanical properties of the new high-water material were investigated through laboratory experiments, and their main advantages were identified. The reasonable width of the roadside filling wall of a high-water material was obtained by combining ground pressure observation and theoretical calculations. The distribution characteristics of the stress and plastic zone of surrounding rock of GER after being stabilized by the disturbance of the working face were studied using numerical simulations, and the failure range of GER by filling with high-water material was revealed. Based on this, a coupling control technology of anchor cables and bolts + single props + metal mesh + anchor bolts is proposed. Through the coupling methods of arranging borehole peeping and observing the convergences of surrounding rock, the results demonstrate that GER with double roadways by filling with a 1.8-m-wide high-water material has a good control effect. The above research will play an active role in promoting the application of high-water materials in GER roadside filling.Applied Science, Faculty ofNon UBCCivil Engineering, Department ofReviewedFacultyResearche

    Effects of Varicocele Surgical Repair on Serum Hormone and Inhibin B Levels for Patients With Varicocele: A Systematic Review and Meta-Analysis

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    Varicocele surgical repair can improve the function of the testis for patients with varicocele. We carried out a systematic review and meta-analysis to assess the effects of varicocele surgical repair on serum hormones and inhibin B levels in patients with varicocele. A literature search was performed in August 2022, and no language or geographic region restrictions were applied. The search included the following databases: PubMed, Embase, and Medline. A literature review was performed to identify all published clinical trials assessing serum hormone and inhibin B levels before and after varicocele surgical repair. The reference lists of retrieved studies were also investigated. A systematic review and meta-analysis were conducted. Eight articles were selected from 162 articles, including 452 patients. The combined analysis showed that after surgical treatment, mean serum testosterone, inhibin B, and sperm concentration levels increased compared with preoperative levels ( p < .05). After surgical treatment, mean serum follicle-stimulating hormon (FSH), and Luteinizing hormone (LH) levels decreased compared with preoperative levels ( p < .05). This meta-analysis demonstrates that varicocele surgical repair can improve testicular function, increase serum testosterone, and inhibin B levels and decrease serum FSH and LH levels in patients with varicocele. This might be related to the improvement of infertility. A large-scale multicenter randomized controlled study is needed for further confirmation
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