110 research outputs found
Cascaded Deep Networks with Multiple Receptive Fields for Infrared Image Super-Resolution
Infrared images have a wide range of military and civilian applications including night vision, surveillance and robotics. However, high-resolution infrared detectors are difficult to fabricate and their manufacturing cost is expensive. In this work, we present a cascaded architecture of deep neural networks with multiple receptive fields to increase the spatial resolution of infrared images by a large scale factor (×8). Instead of reconstructing a high-resolution image from its low-resolution version using a single complex deep network, the key idea of our approach is to set up a mid-point (scale ×2) between scale ×1 and ×8 such that lost information can be divided into two components. Lost information within each component contains similar patterns thus can be more accurately recovered even using a simpler deep network. In our proposed cascaded architecture, two consecutive deep networks with different receptive fields are jointly trained through a multi-scale loss function. The first network with a large receptive field is applied to recover large-scale structure information, while the second one uses a relatively smaller receptive field to reconstruct small-scale image details. Our proposed method is systematically evaluated using realistic infrared images. Compared with state-of-theart Super-Resolution methods, our proposed cascaded approach achieves improved reconstruction accuracy using significantly less parameters
Learning Inter- and Intra-frame Representations for Non-Lambertian Photometric Stereo
In this paper, we build a two-stage Convolutional Neural Network (CNN)
architecture to construct inter- and intra-frame representations based on an
arbitrary number of images captured under different light directions,
performing accurate normal estimation of non-Lambertian objects. We
experimentally investigate numerous network design alternatives for identifying
the optimal scheme to deploy inter-frame and intra-frame feature extraction
modules for the photometric stereo problem. Moreover, we propose to utilize the
easily obtained object mask for eliminating adverse interference from invalid
background regions in intra-frame spatial convolutions, thus effectively
improve the accuracy of normal estimation for surfaces made of dark materials
or with cast shadows. Experimental results demonstrate that proposed masked
two-stage photometric stereo CNN model (MT-PS-CNN) performs favorably against
state-of-the-art photometric stereo techniques in terms of both accuracy and
efficiency. In addition, the proposed method is capable of predicting accurate
and rich surface normal details for non-Lambertian objects of complex geometry
and performs stably given inputs captured in both sparse and dense lighting
distributions.Comment: 9 pages,8 figure
Genome Sequence and Metabolic Analysis of a Fluoranthene-Degrading Strain Pseudomonas aeruginosa DN1
Pseudomonas aeruginosa DN1, isolated from petroleum-contaminated soil, showed excellent degradation ability toward diverse polycyclic aromatic hydrocarbons (PAHs). Many studies have been done to improve its degradation ability. However, the molecular mechanisms of PAHs degradation in DN1 strain are unclear. In this study, the whole genome of DN1 strain was sequenced and analyzed. Its genome contains 6,641,902 bp and encodes 6,684 putative open reading frames (ORFs), which has the largest genome in almost all the comparative Pseudomonas strains. Results of gene annotation showed that this strain harbored over 100 candidate genes involved in PAHs degradation, including those encoding 25 dioxygenases, four ring-hydroxylating dioxygenases, five ring-cleaving dioxygenases, and various catabolic enzymes, transcriptional regulators, and transporters in the degradation pathways. In addition, gene knockout experiments revealed that the disruption of some key PAHs degradation genes in DN1 strain, such as catA, pcaG, pcaH, and rhdA, did not completely inhibit fluoranthene degradation, even though their degradative rate reduced to some extent. Three intermediate metabolites, including 9-hydroxyfluorene, 1-acenaphthenone, and 1, 8-naphthalic anhydride, were identified as the dominating intermediates in presence of 50 μg/mL fluoranthene as the sole carbon source according to gas chromatography mass spectrometry analysis. Taken together, the genomic and metabolic analysis indicated that the fluoranthene degradation by DN1 strain was initiated by dioxygenation at the C-1, 2-, C-2, 3-, and C-7, 8- positions. These results provide new insights into the genomic plasticity and environmental adaptation of DN1 strain
A rare case of 2D+1D → 2D Cd(II) coordination polymer without any entanglements: Synthesis, structure and luminescent property
The reactions of CdCl2·2.5H2O with mixed ligands, H2tfbdc and hmt, under different metal-to-ligand ratios, afford two coordination polymers, namely, [Cd(hmt)(tfbdc)(H2O)2]2·3H2O (1) and {[NH4]2[Cd2(H2hmt)(tfbdc)2Cl4][Cd(H2hmt) (tfbdc)Cl2]}·2H2O (2). Both the complexes have been structurally characterized by X-ray data. Complex 1 has a 2D rectangular grid built up by tfbdc2– and hmt ligands, while 2 consists of distinct 1D anionic ladder [Cd2(H2hmt)(tfbdc)2Cl4]2‒ and 2D grid [Cd(H2hmt)(tfbdc)Cl2] in a crystal. Further, in 2, the 2D net is parallel to the 1D ladder without mutual entanglement or interdigitation. Despite the hydrogen bond interactions and the F···F interactions, only a 2D supermolecular structure is formed in 2. Thus, compound 2 is the first case of 2D+1D→2D coordination polymer without any entanglements
Deep Neural Network for Fast and Accurate Single Image Super-Resolution via Channel-Attention-based Fusion of Orientation-aware Features
Recently, Convolutional Neural Networks (CNNs) have been successfully adopted
to solve the ill-posed single image super-resolution (SISR) problem. A commonly
used strategy to boost the performance of CNN-based SISR models is deploying
very deep networks, which inevitably incurs many obvious drawbacks (e.g., a
large number of network parameters, heavy computational loads, and difficult
model training). In this paper, we aim to build more accurate and faster SISR
models via developing better-performing feature extraction and fusion
techniques. Firstly, we proposed a novel Orientation-Aware feature extraction
and fusion Module (OAM), which contains a mixture of 1D and 2D convolutional
kernels (i.e., 5 x 1, 1 x 5, and 3 x 3) for extracting orientation-aware
features. Secondly, we adopt the channel attention mechanism as an effective
technique to adaptively fuse features extracted in different directions and in
hierarchically stacked convolutional stages. Based on these two important
improvements, we present a compact but powerful CNN-based model for
high-quality SISR via Channel Attention-based fusion of Orientation-Aware
features (SISR-CA-OA). Extensive experimental results verify the superiority of
the proposed SISR-CA-OA model, performing favorably against the
state-of-the-art SISR models in terms of both restoration accuracy and
computational efficiency. The source codes will be made publicly available.Comment: 12 pages, 11 figure
Simulation Study on Spatial Form of the Suspended Roof Structure of Working Face in Shallow Coal Seam
Longwall fully comprehensive mechanized mining is mainly used for the working faces of shallow coal seam with large mining height, which usually have a large suspended roof at the face end. The overhang at the face end leads to stress concentration, which affects the safe mining of the working face. In this paper, we use the 15210 working face with a suspended roof (overhanging area 50~70 m2) of the Zhangjiamao coal mine as study background, with physical simulation, numerical calculation and theoretical analysis, the spatial morphologies and changes in the roof structure at the face ends of the working face in shallow coal seam are obtained, in which the suspended roof increase from the bottom to top, forming step-laminated structures. The caving interval of the suspended roof at the face end is about two times the period weighting interval, and the suspended roof area at the tailgate is smaller than at the headgate. The distribution of the shear and the principal stress field at the face-end region is arc-shaped, and the distribution of the plastic zone shows that the collapse of a suspended ceiling has obvious hysteresis. According to the simplified analysis of the Marcus plate, when the layers of the stepped curved triangular plates increase, the length of the suspended roof on the solid coal side also increases, which is consistent with the results of the physical simulation and numerical calculations. The formation mechanism of the roof at the end of the working face provides a research foundation for the control of roofs found at face ends and further improves the theory of roof structure and the safety mining of suspended roof areas
Research on Overburden Movement Characteristics of Large Mining Height Working Face in Shallow Buried Thin Bedrock
The overburden movement of the large mining height working face of shallow buried thin bedrock (SBTB) is a complex engineering problem with “time-space-intension”, which is of great significance to realize efficient and safe mining in the northern Shaanxi mining area. Based on the research object of No. 22201 working face in Zhangjiamao Coal Mine, the roof structure characteristics of large mining height working face in SBTB are researched by field drilling measurement, laboratory test, physical and numerical simulation. The results show that: (1) Based on the measured data of the drillholes, it is concluded that under the mining conditions of SBTB with large mining height, the roof movement is ahead of the weighting of the working face, and the working resistance has a significant time effect. The advanced movement distance is about 20 m, which can be used as an early warning index of the weighting. The lag movement distance in the roof with horizon of 30 m is two periodic weighting intervals, which are about 26 m. (2) The first weighting interval of the working face is 32 m. The roof first break has obvious step sinking phenomenon, and the measured surface appears at a position 45 m away from the transport slot. It is statistically concluded that the periodic weighting interval is 9.5~16.5 m, the average weighting interval is 13 m, which is equivalent to the periodic dynamic crack spacing of the surface. (3) The results of field measurement and physical simulation show that the breaking angle of the roof of the No. 22201 large mining height is about 66°, and the periodic stepping distance of the T-junction suspension area is 6~8m. Along the strike of the working face, the roof breaking is mainly arc arched. The research results ensure the safe and green mining of shallow coal seam
Simulation Study on Spatial Form of the Suspended Roof Structure of Working Face in Shallow Coal Seam
Longwall fully comprehensive mechanized mining is mainly used for the working faces of shallow coal seam with large mining height, which usually have a large suspended roof at the face end. The overhang at the face end leads to stress concentration, which affects the safe mining of the working face. In this paper, we use the 15210 working face with a suspended roof (overhanging area 50~70 m2) of the Zhangjiamao coal mine as study background, with physical simulation, numerical calculation and theoretical analysis, the spatial morphologies and changes in the roof structure at the face ends of the working face in shallow coal seam are obtained, in which the suspended roof increase from the bottom to top, forming step-laminated structures. The caving interval of the suspended roof at the face end is about two times the period weighting interval, and the suspended roof area at the tailgate is smaller than at the headgate. The distribution of the shear and the principal stress field at the face-end region is arc-shaped, and the distribution of the plastic zone shows that the collapse of a suspended ceiling has obvious hysteresis. According to the simplified analysis of the Marcus plate, when the layers of the stepped curved triangular plates increase, the length of the suspended roof on the solid coal side also increases, which is consistent with the results of the physical simulation and numerical calculations. The formation mechanism of the roof at the end of the working face provides a research foundation for the control of roofs found at face ends and further improves the theory of roof structure and the safety mining of suspended roof areas
Experimental Investigation on Crack Development Characteristics in Shallow Coal Seam Mining in China
The development of cracks in mining is the scientific basis for the safety and environmental exploitation of shallow multiple-seam. According to the “thickness of coal seam, interactive distance, and buried depth,„ four mining coal mines are selected in Shen Fu-Dong Sheng coalfield (SFDSC). To research the mining conditions of shallow coal seam under different base-load ratio mining conditions and different working faces by the physics simulation and in-sit measurement, the key roof caves are sketched by different colors. This study shows that the typical shallow coal seams in the thin overlying bedrock and thick loose sand layer (LSL) as well as the development of the setup entry cracks (SEC) is dominated by LSL arch damage. The surface cracks are almost directly above the setup entry. The flat seam mining and the SEC development is dominated by parabolic type. The surface cracks are located inside the setup entry. With the mining height increased typically in a shallow coal seam, the rate of crack development and the extent of damaged area increased significantly. The SEC and boundary cracks are fixed. The dynamic periodic cracks (DPC) show the ability of the strata to self-repair. During the multiple-seam mining, the above three kinds of cracks have the phenomenon of activation and development. Through the reasonable coal pillar distance arrangement, the development of boundary cracks can be effectively controlled and the relatively uniform surface settlement and crack closure can be achieved. The purpose of reducing damage mining can also be achieved. Furthermore, it provides scientific support for the green mining in the shallow coal seam
Visualization of the surface distributions of reactive oxygen species on model human tissues treated by a He+O
The spatial–temporal distribution of reactive oxygen species (ROS) in human tissue is critical for the medical applications of cold plasma jet as it reflects the therapeutic range of cold plasma jet, but the mechanism for its formation is still unclear. To this end, KI-starch reagent was used to visualize the surface distributions of ROS on the model human tissues treated by a He + O2 plasma jet in this paper. It was found that the surface distribution of ROS was divided into two parts by a small donut-shaped of un-colored area. This un-colored area was resulted from the color fading of the model tissue, which might be induced by the AC electric field of the plasma jet and the plasma-generated reductive species. The colored area and the un-colored area had different trends with the working gas flow rate and the model tissue conductivity. The un-colored area increased with the expansion of the plasma plume and shrank with the increasing model tissue conductivity
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