Note On Certain Inequalities for Neuman Means

In this paper, we give the explicit formulas for the Neuman means $N_{AH}$, $N_{HA}$, $N_{AC}$ and $N_{CA}$, and present the best possible upper and lower bounds for theses means in terms of the combinations of harmonic mean $H$, arithmetic mean $A$ and contraharmonic mean $C$.Comment: 9 page

Damage Effects of Fluid filled Submunitions by High Velocity Projectile Impact

A series of tests investigating the damage effects of fluid-filled submunitions by high velocity projectile impact were conducted. An analytical model is presented, in which the yaw angle of the projectile was taken into account. Based on the analytical model, the influence of the strike angle, hit-point offset distance and projectile length to diameter ratio on submunition damage ratio were predicted. The analytical results showed a good agreement with the experiments. The submunition damage ratio strongly depends on the hit-point offset distance, showing a significant decrease with increasing hit-point offset distance. For large hit-point offset distance, increasing the length to diameter ratio of the projectile will effectively improve the submunition damage ratio. There is an appropriate yaw angle of the projectile in which the submunition damage ratio will be maximal

Gas Production from Methane Hydrate in a Pilot-Scale Hydrate Simulator Using the Huff and Puff Method by Experimental and Numerical Studies

A novel three-dimensional 117.8-L pressure vessel, which is called a Pilot-Scale Hydrate Simulator (PHS), is developed to investigate the gas production performance from hydrate-bearing porous media using the huff and puff method through both experimental and numerical simulations. The methane gas and deionized water are injected into the pressure vessel to synthesize methane hydrate. The grain sizes of the quartz sand in the vessel are between 300 and 450 mu m. The huff and puff stages, including the injection, the soaking, and the production, are employed for hydrate dissociation. A single vertical well at the axis of the PHS is used as the injection and production well. The whole experiment consists of 15 huff and puff cycles. The numerical simulation results agree well with the experiment. Both the experimental and numerical simulation results indicate that the injected water is mainly restricted around the well during the injection stage. The system pressure fluctuates regularly in each cycle, and the secondary hydrate is formed under the pressurization effect caused by the hot water injection in the injection stage. The gas production rate maintains approximately stable in a relatively long period. The sensitivity analysis indicates that the gas production can be enhanced with high intrinsic permeability of the deposit or by raising the temperature of the injected hot water. The mass of the water produced in each cycle has little difference and is manageable when using the huff and puff method.</p

SuperpixelGraph: Semi-automatic generation of building footprint through semantic-sensitive superpixel and neural graph networks

Most urban applications necessitate building footprints in the form of concise vector graphics with sharp boundaries rather than pixel-wise raster images. This need contrasts with the majority of existing methods, which typically generate over-smoothed footprint polygons. Editing these automatically produced polygons can be inefficient, if not more time-consuming than manual digitization. This paper introduces a semi-automatic approach for building footprint extraction through semantically-sensitive superpixels and neural graph networks. Drawing inspiration from object-based classification techniques, we first learn to generate superpixels that are not only boundary-preserving but also semantically-sensitive. The superpixels respond exclusively to building boundaries rather than other natural objects, while simultaneously producing semantic segmentation of the buildings. These intermediate superpixel representations can be naturally considered as nodes within a graph. Consequently, graph neural networks are employed to model the global interactions among all superpixels and enhance the representativeness of node features for building segmentation. Classical approaches are utilized to extract and regularize boundaries for the vectorized building footprints. Utilizing minimal clicks and straightforward strokes, we efficiently accomplish accurate segmentation outcomes, eliminating the necessity for editing polygon vertices. Our proposed approach demonstrates superior precision and efficacy, as validated by experimental assessments on various public benchmark datasets. A significant improvement of 8% in AP50 was observed in vector graphics evaluation, surpassing established techniques. Additionally, we have devised an optimized and sophisticated pipeline for interactive editing, poised to further augment the overall quality of the results

INTERACTIONS AND INFLUENCES ON COAL MINERS' SAFETY ATTENTION: AN EVALUATION USING IMPROVED DEMATEL-ISM

In coal mining, the myriad of factors influencing miners' attention to safety necessitates deeper exploration. Particularly, discerning the significance and interplay of these factors offers crucial insights into the actual disparities in miners' safety attentiveness. Yet, a limited number of comprehensive studies address this dimension. Thus, an advanced Decision Making Trial Evaluation Laboratory-Interpretive Structural Model (DEMATEL-ISM) has been employed to probe the determinants impacting coal miners' safety focus and the mechanisms underpinning these interactions. The objective is to provide strategies that could diminish the occurrence of minor accidents. Results revealed that there are 9 causative factors and 6 resultant factors shaping the coal miners' attention to safety. Within the structural model of these factors, three layers and seven levels were identified. Notably, the intricacy of relationships among these factors was found to be profound. Emphasis is recommended on the management of these intricate deep-level causative factors boasting high driving power, and mid-level resultant factors characterized by both substantial driving force and dependence