Novel View Synthesis from a Single RGBD Image for Indoor Scenes

In this paper, we propose an approach for synthesizing novel view images from a single RGBD (Red Green Blue-Depth) input. Novel view synthesis (NVS) is an interesting computer vision task with extensive applications. Methods using multiple images has been well-studied, exemplary ones include training scene-specific Neural Radiance Fields (NeRF), or leveraging multi-view stereo (MVS) and 3D rendering pipelines. However, both are either computationally intensive or non-generalizable across different scenes, limiting their practical value. Conversely, the depth information embedded in RGBD images unlocks 3D potential from a singular view, simplifying NVS. The widespread availability of compact, affordable stereo cameras, and even LiDARs in contemporary devices like smartphones, makes capturing RGBD images more accessible than ever. In our method, we convert an RGBD image into a point cloud and render it from a different viewpoint, then formulate the NVS task into an image translation problem. We leveraged generative adversarial networks to style-transfer the rendered image, achieving a result similar to a photograph taken from the new perspective. We explore both unsupervised learning using CycleGAN and supervised learning with Pix2Pix, and demonstrate the qualitative results. Our method circumvents the limitations of traditional multi-image techniques, holding significant promise for practical, real-time applications in NVS.Comment: 2nd International Conference on Image Processing, Computer Vision and Machine Learning, November 202

Basic characteristics of mine dust suppression foam and the quantitative evaluation method of its performance

The priority direction of mine dust control is to suppress dust generation and flying at the source. Foam, a gas-liquid two-phase medium, has some unique advantages of large dust covering area, strong adhesion ability and fast wetting of dust. It is an efficient way of dust suppression, especially for respiratory dust. However, there is limited research on the morphology and properties of dust suppression foam in the past, resulting in a certain blindness in the preparation and utilization of dust suppression foam. And there is a problem of a large amount of spray foam in exchange for higher dust suppression efficiency, which restricts the low-cost application of this technology in mines. Therefore, in this study, a theoretical derivation was combined with experimental research and quantitative analysis to study the process and law of dust suppression foam drain, the micromorphology of dust suppression foam, the performance influence mechanism and the quantitative evaluation method. These results show that the drain factor w is related to the height of the foam column and the liquid of foam in the foaming process. The higher height of the dust suppression foam and the greater liquid content, the value of the discharge factor w will be lower. The predicted value of w and the theoretical discharge curve calculated by the drainage model show a high degree of consistency with the experimental results, which verifies the accuracy of the theoretical model. The results show foam size distribution, average diameter with the concentration of foaming agent changes. At a low concentration (1%), the number of foam decreases and large particle size bubbles increase. The addition of low-concentration (<0.3%) polymer to the foaming agent has no obvious effect on the wetting angle of coal dust, but the contact angle increases when enlarging the concentration of polymer. In terms of foaming performance and foam stability performance, the production efficiency and stability of dust suppression foam can be improved after the addition of 0.1% polymer. Based on the analysis of the whole process from the generation of dust suppression foam to its action on the dust cutting source, the indicators for evaluating the foam performance are proposed, and the quantitative evaluation criteria and four grades of dust suppression foam performance are given

A novel method of fuzzy fault tree analysis combined with VB program to identify and assess the risk of coal dust explosions.

Coal dust explosions (CDE) are one of the main threats to the occupational safety of coal miners. Aiming to identify and assess the risk of CDE, this paper proposes a novel method of fuzzy fault tree analysis combined with the Visual Basic (VB) program. In this methodology, various potential causes of the CDE are identified and a CDE fault tree is constructed. To overcome drawbacks from the lack of exact probability data for the basic events, fuzzy set theory is employed and the probability data of each basic event is treated as intuitionistic trapezoidal fuzzy numbers. In addition, a new approach for calculating the weighting of each expert is also introduced in this paper to reduce the error during the expert elicitation process. Specifically, an in-depth quantitative analysis of the fuzzy fault tree, such as the importance measure of the basic events and the cut sets, and the CDE occurrence probability is given to assess the explosion risk and acquire more details of the CDE. The VB program is applied to simplify the analysis process. A case study and analysis is provided to illustrate the effectiveness of this proposed method, and some suggestions are given to take preventive measures in advance and avoid CDE accidents

Novel Approach for Suppressing Cutting Dust Using Foam on a Fully Mechanized Face with Hard Parting

<div><p>The cutting dust created by the shearer drum is the main source of dust on a fully mechanized coal face. However, overexposure to respirable dust may cause pneumoconiosis in coal workers, while coal dust may lead to serious explosions. The fully mechanized face known as II1051 Face, found at the Zhuxianzhuang Coal Mine located in east China, generates dust by way of the drum on a high-power shear. The coal seam involves hard rock parting so there is a high concentration of cutting dust when the shearer is working. Thus, we developed a new foam dust suppression method with an air self-suction system based on an analysis of the dust generation characteristics that suppressed the shearer cutting dust level. The new foam system was evaluated in a field test where the dust concentration was measured at two points. The results showed that the foam reduced the cutting dust concentration significantly. The respirable dust exposure levels were reduced from 378.4 mg/m³to 53.5 mg/m³and the visibility was enhanced dramatically. Thus, we conclude that our new foam system is highly efficient at capturing cutting dust, and it has a much lower water consumption.</p> <p>[Supplementary materials are available for this article. Go to the publisher's online edition of <i>Journal of Occupational and Environmental Hygiene</i> for the following free supplemental resource: Contact angle of cutting dust sample, migration trajectory of cutting dust, technological process for suppressing shearer cutting dust using foam, the layout of the foam dust suppression system on coal face, real object of the air self-suction type foam generator, the special foam nozzle used for shearers, relevant experimental results of the air self-suction foam system.]</p> </div

Investigations of the effects of two typical jet crushing methods on the atomization and dust reduction performance of nozzles

Abstract Single-fluid nozzles and dual-fluid nozzles are the two typical jet crushing methods used in spray dust reduction. To distinguish the atomization mechanism of single-fluid and dual-fluid nozzles and improve dust control efficiency at the coal mining faces, the atomization characteristics and dust reduction performance of the two nozzles were quantitatively compared. Results of experiments show that, as water supply pressure increased, the atomization angle of the swirl pressure nozzle reaches a maximum of 62° at 6 MPa and then decreases, but its droplet size shows an opposite trend with a minimum of 41.7 μm. The water supply pressure helps to improve the droplet size and the atomization angle of the internal mixing air–liquid nozzle, while the air supply pressure has a suppressive effect for them. When the water supply pressure is 0.2 MPa and the air supply pressure reaches 0.4 MPa, the nozzle obtains the smallest droplet size which is 10% smaller than the swirl pressure nozzle. Combined with the dust reduction experimental results, when the water consumption at the working surface is not limited, using the swirl pressure nozzle will achieve a better dust reduction effect. However, the internal mixing air–liquid nozzle can achieve better and more economical dust reduction performance in working environments where water consumption is limited

Weighting scores of different experts.

<p>Weighting scores of different experts.</p

Fuzzy numbers representing linguistic variables.

<p>Fuzzy numbers representing linguistic variables.</p