Intensity Mapping Functions For HDR Panorama Imaging: Weighted Histogram Averaging

It is challenging to stitch multiple images with different exposures due to possible color distortion and loss of details in the brightest and darkest regions of input images. In this paper, a novel intensity mapping algorithm is first proposed by introducing a new concept of weighted histogram averaging (WHA). The proposed WHA algorithm leverages the correspondence between the histogram bins of two images which are built up by using the non-decreasing property of the intensity mapping functions (IMFs). The WHA algorithm is then adopted to synthesize a set of differently exposed panorama images. The intermediate panorama images are finally fused via a state-of-the-art multi-scale exposure fusion (MEF) algorithm to produce the final panorama image. Extensive experiments indicate that the proposed WHA algorithm significantly surpasses the related state-of-the-art intensity mapping methods. The proposed high dynamic range (HDR) stitching algorithm also preserves details in the brightest and darkest regions of the input images well. The related materials will be publicly accessible at https://github.com/yilun-xu/WHA for reproducible research.Comment: 11 pages, 5 figure

Numerical simulation and process optimization on cast steel bearing sleeve

A three-dimensional Computer Aided Design (CAD) model of the bearing sleeve casting is established by Pro/E software. The ViewCast program is utilized for studying casting processes of solidification and mould-filling in order to optimize the casting technology. Based on the solidification simulation, the casting shrinkage and porosity as well as solidification processes are forecast visually in diagrams with the help of ViewCast. The mould-filling simulation results verify whether the fluid/liquid metal fills gates and the mould smoothly. The simulation results of an initial casting scheme show that this scheme is improper. Two optimization schemes have been completed based on the filling simulation so that a modified casting technology is obtained. The simulation results of optimized schemes indicate that the metal fluid fills the mold smoothly and the shrinkage is eliminated effectively. The optimized scheme II is preferred to scheme I. Experimentally, the casting confirms that these optimized methods are very useful in reducing the casting defects and improving the product quality

A dataset describing chip parameters for rock breaking by chisel pick under deep-sea hydrostatic pressure

Chip is a visual representation of rock breaking by cutter, and their related parameters are crucial for revealing the rock breaking mechanism in deep-sea mining. Based on sieving and three-dimensional size measurement methods widely used in mining engineering, this paper reports a dataset of chip parameters for rock breaking by chisel pick under deep-sea hydrostatic pressure. Specifically, we first designed an experimental setup that can accurately simulate deep-sea hydrostatic pressure, conducted rock breaking experiments and carefully collected chips. Subsequently, those chips were sieved, high-resolution images were collected, and the coarseness index (CI), chip size uniformity (n), absolute chip size (de), and fractal dimension (D) were measured. Finally, three-dimensional size (long, intermediate and short) was measured for 3064 chips with particle sizes greater than 4.75 mm. This dataset will be used by researchers to validate numerical simulations or optimize equipment structures related to deep-sea mining, including deep-sea rock mechanics, mining cutter and conveyor pipes

Casting process design and wear properties of a high chromium cast iron hammer

In this article, both chemical composition and structure of a high chromium iron hammer head were designed and analyzed respectively. Also, the casting process was investigated and optimized through numerical simulation using commercial software View Cast. On the basis of numerical simulation and optimization, several hammer heads with fine surface quality and no internal defects were cast into one mold through shell molding and string casting process. In addition, heat treatment of the as-cast hammer head was carried out. Consequently, the microstructure was observed, and wear resistance was tested. After being quenched at the temperature of 950℃ and tempered at the temperature in the range of 230-260℃, the microstructure of the hammer is made up from tempered martensite, retained austenite and network eutectic carbides. The hardness is 60 HRC. Experimental result shows that the wear loss is slowly increased with an increase in load and rotating speed

Research on the grinding performance of high pressure sintering SiCp/Al matrix composites

The two-dimensional vertical grinding test equipment was used to grind SiCp/Al composites which were prepared by high pressure sintering method. The SEM observation of grinding morphology showed that grinding damage can be prevented by SiC particles reinforcement, 60% volume fraction of SiC particles of SiCp/Al composite can hinder grinding depth and grinding performance was improved with the sintering pressure and temperature increasing. In addition, some scratches and exfoliated pits of SiC particles were observed on the surface of 60% volume SiCp/Al composite as the increase of grinding grain, while the depth of these scratches was shallower, there was no large area exfoliated pits of SiC reinforcements

The casting process and high temperature oxidation resistance of high chromium cast iron grate bar

The solidification process of a high chromium cast iron grate bar used for sinter machine was simulated, and high temperature oxidation resistance was also investigated. The simulation result shows that sequence solidification can be achieved and no shrinkage cavity and porosity were observed. Based on the analysis of the microstructure, it could be known that the grate bar was well protected by the Fe3O4、Fe2O3 and Cr2O3 oxide films at temperatures lower than 800°C

In situ immobilization of Ag nanoparticles on Keggin heteropoly blue microtubes †

Silver nanoparticles (NPs)-deposited tungstosilicate (Ag/SiW 12 /Ag) microtubes were obtained by a redox reaction between the heteropoly blue microtubes and Ag + ions. The Ag/SiW 12 /Ag microtubes were characterized by FT-IR and XPS spectroscopy. Their morphology was examined by ESEM-FEG, showing that the microtubes kept their original microtubular morphology well after reacting with Ag + ions and the silver NPs exhibited regular spherical morphology. The current-voltage properties of the Ag/SiW 12 /Ag microtubes were also briefly investigated

Large–scale genetic analysis and biological traits of two SigB factors in Listeria monocytogenes: lineage correlations and differential functions

IntroductionListeria monocytogenes is a globally distributed bacterium that exhibits genetic diversity and trait heterogeneity. The alternative sigma factor SigB serves as a crucial transcriptional regulator essential for responding to environmental stress conditions and facilitating host infection.MethodWe employed a comprehensive genetic analysis of sigB in a dataset comprising 46,921 L. monocytogenes genomes. The functional attributes of SigB were evaluated by phenotypic experiments.ResultsOur study revealed the presence of two predominant SigB factors (SigBT1 and SigBT2) in L. monocytogenes, with a robust correlation between SigBT1 and lineages I and III, as well as SigBT2 and lineage II. Furthermore, SigBT1 exhibits superior performance in promoting cellular invasion, cytotoxicity and enhancing biofilm formation and cold tolerance abilities under minimally defined media conditions compared to SigBT2.DiscussionThe functional characteristics of SigBT1 suggest a potential association with the epidemiology of lineages I and III strains in both human hosts and the natural environment. Our findings highlight the important role of distinct SigB factors in influencing the biological traits of L. monocytogenes of different lineages, thus highlighting its distinct pathogenic and adaptive attributes