254 results on '"cross-scale"'
Search Results
2. Study on the circumferential tensile behavior of SiCf/SiC composite cladding tubes across a broad temperature range: High temperature interface enhancement effect from a cross-scale perspective
- Author
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Li, Xiulun, Yan, Weidong, Dai, Yufeng, Fan, Xinyu, Yan, Zhongwei, Xu, Jian, and Shen, Liangliang
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- 2025
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3. Pumping and shrinking deformation of TSV-Cu under thermal cycling loads: A cross-scale analysis approach
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Fan, Zhengwei, Hou, Kaihong, Chen, Yonggui, Zhang, Shufeng, Wang, Yashun, and Chen, Xun
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- 2025
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4. Cross-scale study of heat transfer performance in metal rubber with complex topological structures
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Tang, Kequan, Shen, Liangliang, Shi, Linwei, Yan, Weidong, Song, Qiang, and Ren, Zhiying
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- 2024
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5. Differentiated impacts of environmental contexts on residents' environmental attitudes towards ecological restoration programs of China's drylands
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Wu, Tianjing, Liu, Yanxu, Wu, Xutong, Liu, Zhifeng, and Xiao, Rui
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- 2024
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6. A cross-scale hygro-mechanical coupling model for hollow glass bead/resin composite materials
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Wang, Jingze and Cui, Weicheng
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- 2023
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7. Photopyroelectric tweezers for versatile manipulation
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Wang, Fang, Liu, Cong, Dai, Zhengjin, Xu, Weizhong, Ma, Xinyue, Gao, Yufeng, Ge, Xuewu, Zheng, Wei, and Du, Xuemin
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- 2025
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8. Remote sensing image destriping with two-stage image decomposition network.
- Author
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Shi, Yu, Wu, Feiyan, Guo, Jian, and Li, Xi
- Abstract
Stripe noise often affects remote sensing images, leading to the degradation of imaging quality and impacting subsequent image processing. Deep learning methods have made remarkable advancements in removing stripes from remote sensing images with their powerful feature extraction capability. However, it is noteworthy that these methods are still insufficient in analysing structural characteristics in the direction of stripes and multi-scale contextual information. To deal with the above issues, we propose a remote sensing image destriping with a two-stage image decomposition network, named TSIDNet, which utilizes the stripe structural characteristics to effectively remove stripe noise while retaining better details. Firstly, stripes are directional, and the structural information of the stripes is mainly concentrated in the image after the differential decomposition of the direction along the stripes. Therefore, a differential decomposition stripe extraction subnetwork (DDSESN) is constructed to generate latent images. Within this subnetwork, we further design a multi-scale cross-fusion residual block (MCRB) and cross-scale fusion attention block (CSFAB) to gradually expand the network's receptive field, which is conducive to extract and remove stripes more completely. Secondly, the features obtained by adding the latent clear image with details extracted from the stripe's reverse direction are input into a DWT decomposition detail enhancement subnetwork (DDDESN), which utilizes the discrete wavelet transform (DWT) and the dense residual network for detail enhancement. Demonstrated through experiments, the proposed TSIDNet enables the removal of image stripes while preserving details, and surpassing the comparative methods in qualitative as well as quantitative evaluations. The code will be provided after acceptance. [ABSTRACT FROM AUTHOR]
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- 2025
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9. Mechanical performance of geopolymers under the influence of radioactive ions, pore size, and cracks based on molecular dynamics and peridynamics.
- Author
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Wang, Tongfang, Jiang, Biao, Guo, Tong, Yongzong, Silang, Huang, Huiping, Fang, Mengxiang, Tu, Yongming, Wang, Chao, and Sas, Gabriel
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TENSILE strength , *MULTISCALE modeling , *MOLECULAR dynamics , *STRENGTH of materials , *CONSTRUCTION materials - Abstract
AbstractGeopolymers can be classified as an emerging, environmentally-friendly construction material. The dense structure of geopolymers means that they are effective for the immobilization of radioactive ions. However, the mechanical properties are intricately affected by radioactive ions, pore size and initial crack, and the underlying mechanisms require further investigation. This study employs a combined molecular dynamics (MD) and peridynamics (PD) approach to analyze the effects of radioactive ions and how changes in pore size and the presence of an initial crack influence the mechanical performance of geopolymers. The results reveal that Cs and Sr ions exert opposing effects on the mechanical properties of NASH; more specifically, Cs ions negatively affect the mechanical properties of geopolymers. Pore size demonstrates a non-linear influence on performance, with models featuring pore diameters of 40–60 nm exhibiting the poorest mechanical properties. Moreover, the presence of an initial crack in the modeled geopolymer significantly reduces Young’s modulus and the ultimate tensile strength of the material. In the applied cross-scale approach, PD simulations validated and extended the MD results to align more closely with experimental values. This study provides a foundation through which multi-scale modeling can be leveraged to optimize geopolymer performance, particularly in the fields of nuclear waste immobilization and advanced construction materials. [ABSTRACT FROM AUTHOR]
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- 2025
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10. A cross-scale hotspot ignition optimisation model based on void collapse and its interaction.
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Liu, Chun, Cheng, Peng-Fei, Xiao, Xin-Yu, and Li, Luo-Jin
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CHEMICAL properties , *EXPLOSIVES , *CALIBRATION - Abstract
A cross-scale hotspot ignition optimisation model is proposed to characterise the ignition stage in pressed energetic materials (PBXs). In the model, to account for heterogeneous effects, a multi-complex nested ubiquitiform optimisation model is developed to characterise the meso-structure feature of PBX and then used to predict the hotspot distribution of PBX. The intensity of hotspot is obtained based on meso-scale void collapse simulations, and the influence of the interaction between voids on hotspot intensity is considered. Then, a cross-scale hotspot ignition optimisation model is developed based on the hotspot distribution and the Arrhenius model. Based on the physical and chemical properties of the material and without the calibration of experimental parameters, the model can calculate the reaction rate of the hotspot ignition for PBX 9501. Finally, the upper and lower limits of ignition reaction rate are obtained by substituting maximum hotspot energy and minimum hotspot energy into the hotspot ignition optimisation model, which provides a certain basis for the safety evaluation and design of explosives. [ABSTRACT FROM AUTHOR]
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- 2025
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11. Outstanding Questions and Future Research on Magnetic Reconnection.
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Nakamura, R., Burch, J. L., Birn, J., Chen, L.-J., Graham, D. B., Guo, F., Hwang, K.-J., Ji, H., Khotyaintsev, Y. V., Liu, Y.-H., Oka, M., Payne, D., Sitnov, M. I., Swisdak, M., Zenitani, S., Drake, J. F., Fuselier, S. A., Genestreti, K. J., Gershman, D. J., and Hasegawa, H.
- Abstract
This short article highlights unsolved problems of magnetic reconnection in collisionless plasma. Advanced in-situ plasma measurements and simulations have enabled scientists to gain a novel understanding of magnetic reconnection. Nevertheless, outstanding questions remain concerning the complex dynamics and structures in the diffusion region, cross-scale and regional couplings, the onset of magnetic reconnection, and the details of particle energization. We discuss future directions for magnetic reconnection research, including new observations, new simulations, and interdisciplinary approaches. [ABSTRACT FROM AUTHOR]
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- 2025
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12. Remote sensing image super-resolution via cross-scale hierarchical transformer
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Yi Xiao, Qiangqiang Yuan, Jiang He, and Liangpei Zhang
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Super-resolution ,transformer ,cross-scale ,hierarchical attention ,remote sensing ,Mathematical geography. Cartography ,GA1-1776 ,Geodesy ,QB275-343 - Abstract
Global and local modeling is essential for image super-resolution tasks. However, current efforts often lack explicit consideration of the cross-scale knowledge in large-scale earth observation scenarios, resulting in suboptimal single-scale representations in global and local modeling. The key motivation of this work is inspired by two observations: 1) There exists hierarchical features at the local and global regions in remote sensing images, and 2) they exhibit scale variation of similar ground objects (e.g. cross-scale similarity). In light of these, this paper presents an effective method to grasp the global and local image hierarchies by systematically exploring the cross-scale correlation. Specifically, we developed a Cross-scale Self-Attention (CSA) to model the global features, which introduces an auxiliary token space to calculate cross-scale self-attention matrices, thus exploring global dependency from diverse token scales. To extract the cross-scale localities, a Cross-scale Channel Attention (CCA) is devised, where multi-scale features are explored and progressively incorporated into an enriched feature. Moreover, by hierarchically deploying CSA and CCA into transformer groups, the proposed Cross-scale Hierarchical Transformer (CHT) can effectively explore cross-scale representations in remote sensing images, leading to a favorable reconstruction performance. Comprehensive experiments and analysis on four remote sensing datasets have demonstrated the superiority of CHT in both simulated and real-world remote sensing scenes. In particular, our CHT outperforms the state-of-the-art approach (TransENet) in terms of PSNR by 0.11 dB on average, but only accounts for 54.8% of its parameters.
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- 2024
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13. Few-shot segmentation based on multi-level and cross-scale clustering.
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Yuan, Shuai, Qiu, Junhai, Xu, Hongxia, Zhang, Yan, and Zhang, Jiaxing
- Subjects
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IMAGE segmentation , *ALGORITHMS , *FUZZY algorithms - Abstract
The problem of image segmentation with few-shot learning is addressed in this paper, which is a challenging task due to the lack of sufficient high-precision annotated data. A novel method that consists of two modules is proposed: a multi-level fuzzy clustering guidance module and a cross-scale feature fusion module. The former module can extract image features in a class-independent feature space and fuse them with different scale information, while the latter module can reduce the information loss caused by cross-scale transmission. The feature association map between the support image and the query image can be learned by the proposed method, and the inconsistency of target object categories can be overcome. The proposed method is evaluated on Pascal and COCO datasets, and it is shown that it outperforms the state-of-the-art algorithms in both one-shot and k-shot segmentation scenarios. [ABSTRACT FROM AUTHOR]
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- 2024
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14. Remote sensing image super-resolution via cross-scale hierarchical transformer.
- Author
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Xiao, Yi, Yuan, Qiangqiang, He, Jiang, and Zhang, Liangpei
- Subjects
REMOTE sensing ,HIGH resolution imaging ,EMPLOYEE motivation - Abstract
Global and local modeling is essential for image super-resolution tasks. However, current efforts often lack explicit consideration of the cross-scale knowledge in large-scale earth observation scenarios, resulting in suboptimal single-scale representations in global and local modeling. The key motivation of this work is inspired by two observations: 1) There exists hierarchical features at the local and global regions in remote sensing images, and 2) they exhibit scale variation of similar ground objects (e.g. cross-scale similarity). In light of these, this paper presents an effective method to grasp the global and local image hierarchies by systematically exploring the cross-scale correlation. Specifically, we developed a Cross-scale Self-Attention (CSA) to model the global features, which introduces an auxiliary token space to calculate cross-scale self-attention matrices, thus exploring global dependency from diverse token scales. To extract the cross-scale localities, a Cross-scale Channel Attention (CCA) is devised, where multi-scale features are explored and progressively incorporated into an enriched feature. Moreover, by hierarchically deploying CSA and CCA into transformer groups, the proposed Cross-scale Hierarchical Transformer (CHT) can effectively explore cross-scale representations in remote sensing images, leading to a favorable reconstruction performance. Comprehensive experiments and analysis on four remote sensing datasets have demonstrated the superiority of CHT in both simulated and real-world remote sensing scenes. In particular, our CHT outperforms the state-of-the-art approach (TransENet) in terms of PSNR by 0.11 dB on average, but only accounts for 54.8% of its parameters. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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15. LT-DeepLab: an improved DeepLabV3+ cross-scale segmentation algorithm for Zanthoxylum bungeanum Maxim leaf-trunk diseases in real-world environments.
- Author
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Yang, Tao, Wei, Jingjing, Xiao, Yongjun, Wang, Shuyang, Tan, Jingxuan, Niu, Yupeng, Duan, Xuliang, Pan, Fei, and Pu, Haibo
- Subjects
PLANT diseases ,LEAF spots ,DEEP learning ,FEATURE extraction ,CROP management - Abstract
Introduction: Zanthoxylum bungeanum Maxim is an economically significant crop in Asia, but large-scale cultivation is often threatened by frequent diseases, leading to significant yield declines. Deep learning-based methods for crop disease recognition have emerged as a vital research area in agriculture. Methods: This paper presents a novel model, LT-DeepLab, for the semantic segmentation of leaf spot (folium macula), rust, frost damage (gelu damnum), and diseased leaves and trunks in complex field environments. The proposed model enhances DeepLabV3+ with an innovative Fission Depth Separable with CRCC Atrous Spatial Pyramid Pooling module, which reduces the structural parameters of Atrous Spatial Pyramid Pooling module and improves cross-scale extraction capability. Incorporating Criss-Cross Attention with the Convolutional Block Attention Module provides a complementary boost to channel feature extraction. Additionally, deformable convolution enhances low-dimensional features, and a Fully Convolutional Network auxiliary header is integrated to optimize the network and enhance model accuracy without increasing parameter count. Results: LT-DeepLab improves the mean Intersection over Union (mIoU) by 3.59%, the mean Pixel Accuracy (mPA) by 2.16%, and the Overall Accuracy (OA) by 0.94% compared to the baseline DeepLabV3+. It also reduces computational demands by 11.11% and decreases the parameter count by 16.82%. Discussion: These results indicate that LT-DeepLab demonstrates excellent disease segmentation capabilities in complex field environments while maintaining high computational efficiency, offering a promising solution for improving crop disease management efficiency. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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16. Effects of aqueous nanoparticle suspension injection on a shale's mechanical properties.
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Wu, Yongkang, Li, Yucheng, Luo, Shengmin, Lu, Meng, Zhou, Nancy, He, Li, Deng, Yongfeng, and Zhang, Guoping
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COMPUTED tomography , *YOUNG'S modulus , *NANOPARTICLES , *CARBON-black , *X-ray microscopy - Abstract
This paper presents the first effort to unravel and quantify the strengthening of a shale induced by nanoparticle injection from the perspectives of cross-scale and multi-constituent mechanical properties. After being subject to injection of pure water and an aqueous suspension of carbon black nanoparticle of ~ 50 nm in diameter under a differential pressure of 850 kPa, the shale specimens were characterized by big data nanoindentation (BDNi) to probe the mechanical properties of both individual constituents at the microscale and the bulk rock at the macroscale, leading to comparatively assessing the effects of injecting pure water and aqueous nanoparticle suspension on the mechanical properties. Microstructural characterization by electron microscopy and X-ray computed tomography validates the successful injection of nanoparticles into the microcracks and micropores of the rock. While the nanoparticles can infiltrate to depths of up to 100 s μm in zones with densely populated microcracks, the maximum depths of injection in crack-free zones are only 2–5 μm. Moreover, the injected nanoparticles mostly act as inert fillers in the interconnected micropores and microcracks but can seldom enter the isolated micropores. Comparison of the BDNi results from pure water versus nanoparticle-injected specimens shows that the Young's modulus of the clay matrix experiences the highest increase by 23.1%, while the counterpart of non-porous quartz the lowest by 12.8%. Overall, the bulk shale's Young's modulus increases by 21.5%. Such data are consistent with the microcharacterization results that the injected nanoparticles mainly remain in the micropores and microcracks within the clay matrix. Owing to their hydrophobic nature, the carbon black nanoparticles have little effect on the rock's hardness. The findings can shed light on the practical applications of nanoparticle injection for improved wellbore stability in shale formations. [ABSTRACT FROM AUTHOR]
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- 2024
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17. MBV-Pipe: A One-Stop Toolbox for Assessing Mouse Brain Morphological Changes for Cross-Scale Studies.
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Jiang, Wentao, Liu, Xinyi, Song, Ming, Yang, Zhengyi, Sun, Lan, and Jiang, Tianzi
- Abstract
Mouse models are crucial for neuroscience research, yet discrepancies arise between macro- and meso-scales due to sample preparation altering brain morphology. The absence of an accessible toolbox for magnetic resonance imaging (MRI) data processing presents a challenge for assessing morphological changes in the mouse brain. To address this, we developed the MBV-Pipe (Mouse Brain Volumetric Statistics-Pipeline) toolbox, integrating the methods of Diffeomorphic Anatomical Registration Through Exponentiated Lie Algebra (DARTEL)-Voxel-based morphometry (VBM) and Tract-Based Spatial Statistics (TBSS) to evaluate brain tissue volume and white matter integrity. To validate the reliability of MBV-Pipe, brain MRI data from seven mice at three time points (in vivo, post-perfusion, and post-fixation) were acquired using a 9.4T ultra-high MRI system. Employing the MBV-Pipe toolbox, we discerned substantial volumetric changes in the mouse brain following perfusion relative to the in vivo condition, with the fixation process inducing only negligible variations. Importantly, the white matter integrity was found to be largely stable throughout the sample preparation procedures. The MBV-Pipe source code is publicly available and includes a user-friendly GUI for facilitating quality control and experimental protocol optimization, which holds promise for advancing mouse brain research in the future. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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18. Climate change adaptation attributes across scales and inter-institutional networks: insights from national and state level water management institutions in India.
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Azhoni, Adani, Holman, Ian, and Jude, Simon
- Abstract
Effective climate change adaptation requires cohesive inter-institutional networks across different scales, facilitating the sharing of data, information, knowledge, and practices. However, the impact of adaptation attributes across scales is poorly understood due to limited focus on these networks. Based on interviews with 26 institutions operating at the national level (ION) in India and 26 institutions operating within a state (Himachal Pradesh) (IOS), this study analysed adaptation attributes and the inter-institutional networks across the two scales to understand its implications at different scales. IONs have a greater capacity (compared to IOS) to frame guidelines, standards and regulations for practitioners along with better accessibility to resources and information. When coupled with bridging institutions, this can enhance adaptive capacities at other scales. Conversely, learnings from low regret adaptive measures being implemented by IOS are opportunities for informing national policy strategies. While national adaptation strategies and goals can inspire adaptation at lower scales, the currently fragmented inter-institutional network in India reduces the passage and accessibility of data and information, creating a bottleneck for the smooth devolution of adaptation attributes. Recruitment and deployment practices for water officials further entrench silo attitudes, impeding essential data accessibility. Adaptation needs comprehensive networks across vertical, horizontal, and diagonal institutional connections to improve climate risk perception and strategy implementation. Policy measures should consider socio-institutional factors beyond legislative prescriptions. [ABSTRACT FROM AUTHOR]
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- 2024
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19. Cross-Scale Modeling of Shallow Water Flows in Coastal Areas with an Improved Local Time-Stepping Method.
- Author
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Liu, Guilin, Ji, Tao, Wu, Guoxiang, Tian, Hao, and Yu, Pubing
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WATER depth ,TIDAL flats ,TIDE-waters ,COASTAL engineering ,OCEAN engineering - Abstract
A shallow water equations-based model with an improved local time-stepping (LTS) scheme is developed for modeling coastal hydrodynamics across multiple scales, from large areas to detailed local regions. To enhance the stability of the shallow water model for long-duration simulations and at larger LTS gradings, a prediction-correction method using a single-layer interface that couples coarse and fine time discretizations is adopted. The proposed scheme improves computational efficiency with an acceptable additional computational burden and ensures accurate conservation of time truncation errors in a discrete sense. The model performance is verified with respect to conservation and computational efficiency through two idealized tests: the spreading of a drop of shallow water and a tidal flat/channel system. The results of both tests demonstrate that the improved LTS scheme maintains precision as the LTS grading increases, preserves conservation properties, and significantly improves computational efficiency with a speedup ratio of up to 2.615. Furthermore, we applied the LTS scheme to simulate tides at grid scales of 40,000 m to 200 m for a portion of the Northwest Pacific. The proposed model shows promise for modeling cross-scale hydrodynamics in complex coastal and ocean engineering problems. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
20. LT-DeepLab: an improved DeepLabV3+ cross-scale segmentation algorithm for Zanthoxylum bungeanum Maxim leaf-trunk diseases in real-world environments
- Author
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Tao Yang, Jingjing Wei, Yongjun Xiao, Shuyang Wang, Jingxuan Tan, Yupeng Niu, Xuliang Duan, Fei Pan, and Haibo Pu
- Subjects
Zanthoxylum bungeanum Maxim ,cross-scale ,real-world environments ,disease segmentation ,small target ,deep learning ,Plant culture ,SB1-1110 - Abstract
IntroductionZanthoxylum bungeanum Maxim is an economically significant crop in Asia, but large-scale cultivation is often threatened by frequent diseases, leading to significant yield declines. Deep learning-based methods for crop disease recognition have emerged as a vital research area in agriculture.MethodsThis paper presents a novel model, LT-DeepLab, for the semantic segmentation of leaf spot (folium macula), rust, frost damage (gelu damnum), and diseased leaves and trunks in complex field environments. The proposed model enhances DeepLabV3+ with an innovative Fission Depth Separable with CRCC Atrous Spatial Pyramid Pooling module, which reduces the structural parameters of Atrous Spatial Pyramid Pooling module and improves cross-scale extraction capability. Incorporating Criss-Cross Attention with the Convolutional Block Attention Module provides a complementary boost to channel feature extraction. Additionally, deformable convolution enhances low-dimensional features, and a Fully Convolutional Network auxiliary header is integrated to optimize the network and enhance model accuracy without increasing parameter count.ResultsLT-DeepLab improves the mean Intersection over Union (mIoU) by 3.59%, the mean Pixel Accuracy (mPA) by 2.16%, and the Overall Accuracy (OA) by 0.94% compared to the baseline DeepLabV3+. It also reduces computational demands by 11.11% and decreases the parameter count by 16.82%.DiscussionThese results indicate that LT-DeepLab demonstrates excellent disease segmentation capabilities in complex field environments while maintaining high computational efficiency, offering a promising solution for improving crop disease management efficiency.
- Published
- 2024
- Full Text
- View/download PDF
21. CS-CoLBP: Cross-Scale Co-occurrence Local Binary Pattern for Image Classification
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Xiao, Bin, Shi, Danyu, Bi, Xiuli, Li, Weisheng, and Gao, Xinbo
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- 2024
- Full Text
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22. Cross-scale static/dynamic shear damage evolution mechanism of 2D C/SiC ceramic matrix composite with transient hysteresis effect.
- Author
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Shen, Liangliang, Zhu, Tianqi, Shi, Shilun, Xu, Jian, Wang, Jianyue, and Zhang, Chao
- Subjects
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FRACTURE mechanics , *HYSTERESIS , *STRAIN rate , *STRENGTH of materials , *STRESS concentration , *DYNAMIC loads - Abstract
The intricate woven structure of two-dimensional woven carbon fiber-reinforced silicon carbide (2D C/SiC) poses challenges to the investigation of damage failure mechanisms and the prediction of material performance, thereby limiting its further application in aerospace engineering. In this work, static/dynamic short beam shear tests with different densities of 2D C/SiC were carried out. It was observed that high-density specimens with fewer microporous defects exhibited better strength characteristics than those with lower density. Specifically, the shear strength of 2D C/SiC with a density of 2.07 g/cm³ increased by 18.6% compared to that of the specimen with a density of 1.94 g/cm³. The transient hysteresis strengthening effect of materials at high strain rates was discovered through cross scale research methods. It was found that deformation coordination ability of 2D C/SiC under dynamic loading was weaker than that under quasi-static conditions. Moreover, the deformation hysteresis in temporal and spatial distributions induced significant fiber plucking, further accelerating dislocation movement within the internal lattice and thereby enhancing strength of the material. The failure path of materials often follows the direction of pore defects, and stress concentration leads to cracking behavior of fiber bundles. Furthermore, microcracks within the matrix, caused by residual stress, resulted in localized regions of reduced strength. This induced the matrix cracking failure with further crack expansion within the material structure under external loads. To provide technical references for practical engineering applications and design, a realistic and effective finite element prediction model was developed for 2D C/SiC composites based on their structural characteristics. • Exploring the mapping relationship between material micropore defects and density, as well as the impact mechanism on material failure forms. • The transient hysteresis strengthening effect of the specimens under dynamic loads was proposed. • A real and effective 2D C/SiC finite element performance prediction model was constructed. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
23. Cross-Regional Crop Classification Based on Sentinel-2.
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He, Jie, Zeng, Wenzhi, Ao, Chang, Xing, Weimin, Gaiser, Thomas, and Srivastava, Amit Kumar
- Subjects
- *
REMOTE-sensing images , *CLASSIFICATION , *CROPS , *CLOUDINESS , *AGRICULTURE , *AGRICULTURAL water supply - Abstract
Accurate crop classification is of vital importance for agricultural water management. Most researchers have achieved crop classification by model optimization in the same temporal and regional domain by adjusting the value of input features. This study aims to improve the accuracy of crop classification across temporal and spatial domains. Sentinel-2 satellite imagery is employed for crop classification training and prediction in selected farming areas of Heilongjiang Province by calculating vegetation indices and constructing sequential input feature datasets. The HUNTS filtering method was used to mitigate the influence of cloud cover, which increased the stability and completeness of the input feature data across different years. To address the issue of shifts in the input feature values during cross-scale classification, this study proposes the hypothesis testing distribution method (HTDM). This method balances the distribution of input feature values in the test set even without knowing the crop distribution, thereby enhancing the accuracy of the classification test set. The results indicate that the HTDM significantly improves prediction accuracy in cases of substantial image quality variance. In 2022, the recognition accuracy for crop types at all farms processed by the HTDM was above 87%, showcasing the strong robustness of the HTDM. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
24. A Review of Cross-Scale Theoretical Contact Models for Bolted Joints Interfaces.
- Author
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Liu, Yilong, Zhu, Min, Lu, Xiaohan, Wang, Shengao, and Li, Ziwei
- Subjects
BOLTED joints ,PARAMETER identification ,RELIABILITY in engineering ,STATISTICAL models ,SURFACE structure ,FRACTALS - Abstract
Bolted joints structures are critical fastening components widely used in mechanical equipment. Under long-term loading conditions, the bolted joints interface generates strong nonlinearities within the system. The nonlinear stiffness inside the bolt leads to changes in the stiffness of the whole system. This affects the dynamic characteristics of the whole system. It brings challenges and difficulties to the performance prediction and reliability assessment of the equipment. A cross-scale theoretical model study based on the microscopic contact mechanism can provide a more comprehensive understanding and cognition of the degradation behavior of bolted joints interfaces. The current development status and deformation process of asperity models are summarized. The research progress of statistical summation model and contact fractal model based on microscopic contact mechanism is analyzed. The experimental methods for parameter identification of connection interfaces are reviewed. The study of numerical modelling of bolted joints structures from the surface contact mechanism is briefly described. Future research directions for cross-scale modelling of bolted joints structures are outlined. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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25. Nanomechanical behavior of coal with heterogeneous minerals and pores using nanoindentation.
- Author
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Nie, Baisheng, He, Hengyi, Liu, Peng, Liu, Xianfeng, Deng, Bozhi, Zhao, Yulong, Zhang, Hao, and Cao, Mingwei
- Subjects
COAL ,ANTHRACITE coal ,NANOMECHANICS ,COAL combustion ,POROSITY ,MINE safety ,ELASTIC modulus - Abstract
The coal's mechanical properties have a significant influence on mining safety and the mine environment. Preparing a standard sample and conducting repeat mechanical testing are challenging because the coal is primarily soft, fragmented, and rich in developed fractures. This study used nanoindentation technology, combined with X-ray diffraction, small-angle X-ray, a high magnification microscope, and mechanical parameter scale-up analysis, to study the micromechanical of three coals being dominated by heterogeneous components and pores. The results show that load–displacement curves with different maximum loads (50 mN, 100 mN, and 200 mN) all appear the pop-in events, and coal heterogeneity affects the frequency of their occurrence. As the maximum load is increased, pop-in event of DSC appears once each, YW increases from zero to three times and HM decreases from four to two times. The heterogeneity of pore structure has little effect on residual displacement, which is mainly affected by hard minerals, and hard minerals reduce the law that residual displacement increases with the increase in maximum load. The micromechanical parameters of soft coals are mainly affected by large pores, while hard coals are mainly affected by hard minerals. The coal's heterogeneity does not affect the linear relationship between hardness and elastic modulus, but stronger heterogeneity will weaken the linear relationship between fracture toughness and elastic modulus. Compared to the mechanical parameters after scale-up, the values obtained based on nanoindentation are less than 15.588% larger, and the increase in the heterogeneity and hard minerals can make the predicted parameters more accurate. The nanoindentation technique can not only provide an efficient and accurate method for studying the mechanical properties of heterogeneous coal at the nanoscale, an important guide for large-scale coal. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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26. The implicit stabilized dual-horizon peridynamics-based strain gradient damage model.
- Author
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Bie, Yehui, Wei, Yueguang, Rabczuk, Timon, and Ren, Huilong
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STRAINS & stresses (Mechanics) , *DAMAGE models , *FRACTURE mechanics , *CRACK propagation , *STRAIN energy - Abstract
• The GDH-PD is proposed to address size-dependent effects and fracture problems. • The lower- and higher-order micro-modulus states of GDH-PD are firstly derived. • GDH-PD eliminates zero-energy modes of traditional higher-order peridynamics. • HOBCs are applied by constructing quadratic functional on the boundary points. • Nonlocal effects, size effects, strain gradient effects and damage are considered. In this paper, we propose the implicit stabilized dual-horizon peridynamics-based strain gradient damage model (GDH-PD) to describe the cross-scale fracture behavior of materials. To this end, firstly, the strain energy density function of GDH-PD is reformulated by considering the energy compensation to eliminate zero-energy modes of the traditional higher-order peridynamics. And then, the constitutive force state of GDH-PD is derived and explicitly expressed with the help of the proposed special dimension reduction of the nonlocal higher-order tensors. To solve the steady-state crack propagation problems, the implicit GDH-PD is developed by deriving the lower- and higher-order micro-modulus double state, such that the linearization of the equilibrium equation of GDH-PD is established. At last, the bond length-dependent energy-based failure criterion is used to characterize the cross-scale fracture in the form of bond breakage. The effectiveness of GDH-PD to characterize microstructure size effects and macrostructure strain gradient effects are investigated by numerical simulations. The numerical results are in good agreement with the analytical solutions or the available experimental results. We believe that the proposed GDH-PD may pave the way to an increased application of peridynamics to be used in the cross-scale fracture predictions for the advanced material. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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27. Actor Resistance Influences Effectiveness of Ostrom’s Design Principles for Governing Contested Landscapes
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Sivee Chawla, Tiffany H. Morrison, and Graeme S. Cumming
- Subjects
peri-urban ,social ecological systems ,cross-scale ,heterogeneity ,appropriation ,resistance ,Political institutions and public administration (General) ,JF20-2112 - Abstract
Ostrom’s principles for the effective management of common pool resources emphasize the importance of local participation by affected actors in the design of rules. Principle 3 proposes that including local knowledge will facilitate the creation of effective rules that fit local social and ecological settings. However, the validity of the design principles is challenged in situations of high actor heterogeneity. We used a dynamic, spatially explicit simulation model to test Principle 3 in a simulated peri-urban area of a fast-growing city. In the model, urban actors appropriate land in a peri-urban social-ecological system. Urban appropriation fragments peri-urban ecosystems while reducing land availability for rural activities such as agriculture. We simulated the consequences of individual rural and urban actor decisions on emerging patterns of land-use types, using game theory to quantify competition for land, and metrics of landscape composition and configuration to quantify the impacts of rural resistance on landscape patterns. Landscape metrics relevant to ecosystem service provision (urban patch area, number of urban patches, clumping of urban patches and edge density of urban patches) had a non-linear response to resistance to urbanisation. Our results suggest that a small percentage of resisting rural actors can influence emerging landscape patterns; resistance as low as 10% of the rural population to urbanisation was sufficient to influence the degree of clumping of urban areas. The non-linear and varying response of emerging landscape patterns to conflict among actors, and the presence of tipping points for ecological processes that depend on connectivity or area, can create significant opportunities and challenges for the sustainable governance of land-use change in a spatially dynamic SES. We conclude that efforts to use Ostrom’s design principles to manage complex and dynamic landscapes such as peri-urban SESs must account for actor heterogeneity and the potential influence of actor resistance on landscape patterns.
- Published
- 2024
- Full Text
- View/download PDF
28. Cosine modulated filter bank‐based architecture for extracting and fusing saliency features.
- Author
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Ali, Md. Yousuf, Jiang, Bin, Chowdhury, Oindrila, Harun‐Ar‐Rashid, Md., Hossain, M. Shamim, and AlMutib, Khalid
- Subjects
- *
CONTENT-based image retrieval , *COMPUTER vision , *FILTER banks , *FEATURE extraction , *IMAGE segmentation - Abstract
Many academics are interested in content‐based image retrieval techniques like image segmentation. In computer vision, the most popular method for segmenting a digital image into different parts is known as image segmentation. We assigned the artificially intelligent algorithm to the image's critical areas by modeling human features in specific regions. In order to detect the object and identify the key parts in the 'RGB' photographs, we combined scenes based on a colour and depth map, or 'RGB‐D', and used cosine modulated filter bank (CMFB), which conducts cross‐scale extraction of joint features from the images during feature extraction. The proposed 'CMFB' combines the discovered collaborative elements with the discovered supplementary data. The features in multi‐scale images is combined using fusion blocks with the goal of producing additional features (FB). Then, a saliency mapping calculation is made for the loss linked to two blocks. The suggested 'CMFB' is tested with the aid of five data sets, and it is shown that, the proposed 'CMFB' outperforms other conventional techniques. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
29. Catchment concentration–discharge relationships across temporal scales: A review.
- Author
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Speir, Shannon L., Rose, Lucy A., Blaszczak, Joanna R., Kincaid, Dustin W., Fazekas, Hannah M., Webster, Alex J., Wolford, Michelle A., Shogren, Arial J., and Wymore, Adam S.
- Subjects
- *
WATER quality , *RESEARCH personnel , *TIME series analysis - Abstract
Processes that drive variability in catchment solute sourcing, transformation, and transport can be investigated using concentration–discharge (C–Q) relationships. These relationships reflect catchment and in-stream processes operating across nested temporal scales, incorporating both short and long-term patterns. Scientists can therefore leverage catchment-scale C–Q datasets to identify and distinguish among the underlying meteorological, biological, and geological processes that drive solute export patterns from catchments and influence the shape of their respective C–Q relationships. We have synthesized current knowledge regarding the influence of biological, geological, and meteorological processes on C–Q patterns for various solute types across diel to decadal time scales. We identify cross-scale linkages and tools researchers can use to explore these interactions across time scales. Finally, we identify knowledge gaps in our understanding of C–Q temporal dynamics as reflections of catchment and in-stream processes. We also lay the foundation for developing an integrated approach to investigate cross-scale linkages in the temporal dynamics of C–Q relationships, reflecting catchment biogeochemical processes and the effects of environmental change on water quality. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
30. Predicting drug–target binding affinity with cross-scale graph contrastive learning.
- Author
-
Wang, Jingru, Xiao, Yihang, Shang, Xuequn, and Peng, Jiajie
- Subjects
- *
DRUG discovery , *MOLECULAR structure , *DRUG repositioning , *MOLECULAR docking , *ESSENTIAL drugs , *CYCLOSERINE - Abstract
Identifying the binding affinity between a drug and its target is essential in drug discovery and repurposing. Numerous computational approaches have been proposed for understanding these interactions. However, most existing methods only utilize either the molecular structure information of drugs and targets or the interaction information of drug–target bipartite networks. They may fail to combine the molecule-scale and network-scale features to obtain high-quality representations. In this study, we propose CSCo-DTA, a novel c ross- s cale graph co ntrastive learning approach for d rug- t arget binding a ffinity prediction. The proposed model combines features learned from the molecular scale and the network scale to capture information from both local and global perspectives. We conducted experiments on two benchmark datasets, and the proposed model outperformed existing state-of-art methods. The ablation experiment demonstrated the significance and efficacy of multi-scale features and cross-scale contrastive learning modules in improving the prediction performance. Moreover, we applied the CSCo-DTA to predict the novel potential targets for Erlotinib and validated the predicted targets with the molecular docking analysis. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
31. Actor Resistance Influences Effectiveness of Ostrom's Design Principles for Governing Contested Landscapes.
- Author
-
CHAWLA, SIVEE, MORRISON, TIFFANY H., and CUMMING, GRAEME S.
- Abstract
Ostrom's principles for the effective management of common pool resources emphasize the importance of local participation by affected actors in the design of rules. Principle 3 proposes that including local knowledge will facilitate the creation of effective rules that fit local social and ecological settings. However, the validity of the design principles is challenged in situations of high actor heterogeneity. We used a dynamic, spatially explicit simulation model to test Principle 3 in a simulated peri-urban area of a fast-growing city. In the model, urban actors appropriate land in a peri-urban social-ecological system. Urban appropriation fragments peri-urban ecosystems while reducing land availability for rural activities such as agriculture. We simulated the consequences of individual rural and urban actor decisions on emerging patterns of land-use types, using game theory to quantify competition for land, and metrics of landscape composition and configuration to quantify the impacts of rural resistance on landscape patterns. Landscape metrics relevant to ecosystem service provision (urban patch area, number of urban patches, clumping of urban patches and edge density of urban patches) had a non-linear response to resistance to urbanisation. Our results suggest that a small percentage of resisting rural actors can influence emerging landscape patterns; resistance as low as 10% of the rural population to urbanisation was sufficient to influence the degree of clumping of urban areas. The non-linear and varying response of emerging landscape patterns to conflict among actors, and the presence of tipping points for ecological processes that depend on connectivity or area, can create significant opportunities and challenges for the sustainable governance of land-use change in a spatially dynamic SES. We conclude that efforts to use Ostrom's design principles to manage complex and dynamic landscapes such as peri-urban SESs must account for actor heterogeneity and the potential influence of actor resistance on landscape patterns. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
32. Modeling of cross-scale human activity for digital twin workshop [version 2; peer review: 2 approved]
- Author
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Liang Fu, Pei Zhang, Mengming Xia, Ke Chen, Tingyu Liu, Yifeng Sun, and Qing Hong
- Subjects
Digital twin shop-floor ,Human behavior ,Cross-scale ,Macro-behavior ,Micro-behavior ,Theoretical system ,eng ,Computer engineering. Computer hardware ,TK7885-7895 ,Technological innovations. Automation ,HD45-45.2 - Abstract
Digital Twin Workshop(DTW), as an important approach to digitalization and intelligentization of workshop, has gained significant attention in manufacturing industry. Currently, digital twin models for manufacturing resources have progressed from theoretical research to practical implementation. However, as a crucial component of workshop, modeling of human activity in workshop still faces challenges due to the autonomy and uncertainty of human beings. Therefore, we propose a comprehensive approach to the modeling cross-scale human activity in digital twin workshop, which comprises macro activity and micro activity. Macro activity contains human’s occupation and spatial positions in workshop, while micro activity refers to real-time posture and production actions at work. In this paper, we build and integrate macro activity digital twin model and micro activity digital twin model. With the combination of closed-loop interaction between virtual models and physical entities, we achieve semantic mapping and control of production activities, thereby facilitating practical management of human activity in workshop. Finally, we take certain factory’s manufacturing workshop as an example to introduce the application of the proposed approach.
- Published
- 2024
- Full Text
- View/download PDF
33. Multiple frequency–spatial network for RGBT tracking in the presence of motion blur.
- Author
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Fan, Shenghua, Chen, Xi, He, Chu, Yu, Lei, Mao, Zhongjie, and Zheng, Yujin
- Subjects
- *
INFRARED imaging , *THERMOGRAPHY , *CAMERA movement , *INFORMATION networks , *CAMERAS - Abstract
RGBT tracking combines visible and thermal infrared images to achieve tracking and faces challenges due to motion blur caused by camera and target movement. In this study, we observe that the tracking in motion blur is significantly affected by both frequency and spatial aspects. And blurred targets exhibit sharp texture details that are represented as high-frequency information. But existing trackers capture low-frequency components while ignoring high-frequency information. To enhance the representation of sharp information in blurred scenes, we introduce multi-frequency and multi-spatial information in network, called FSBNet. First, we construct a modality-specific unsymmetrical architecture and integrate an adaptive soft threshold mechanism into a DCT-based multi-frequency channel attention adapter (DFDA). DFDA adaptively integrates rich multi-frequency information. Second, we propose a masked frequency-based translation adapter (MFTA) to refine drifting failure boxes caused by camera motion. Moreover, we find that small targets get more affected by motion blur compared to larger targets, and we mitigate this issue by designing a cross-scale mutual conversion adapter (CFCA) between the frequency and spatial domains. Extensive experiments on GTOT, RGBT234 and LasHeR benchmarks demonstrate the promising performance of our method in the presence of motion blur. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
34. Cross-scale Graph Interaction Network for Semantic Segmentation of Remote Sensing Images.
- Author
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JIE NIE, LEI HUANG, CHENGYU ZHENG, XIAOWEI LV, and RUI WANG
- Abstract
Semantic segmentation of remote sensing (RS) images plays a vital role in a variety of fields, including urban planning, natural disaster monitoring, and land resource management. Due to the complexity and low resolution of RS images,many approaches have been proposed to handle the related task. However, these previously developed approaches dedicate to contextual interaction but ignore the cross-scale semantic correlation and multi-scale boundary information. Therefore, we propose a Cross-scale Graph Interaction Network (CGIN) to address semantic segmentation problems of RS images, which consists of a semantic branch and a boundary branch. In the semantic branch, we first apply atrous convolution to extract multi-scale semantic features of RS images. Particularly, based on the multi-scale semantic features, a Cross-scale Graph Interaction (CGI) module is introduced, which establishes cross-scale graph structures and performs adaptive graph reasoning to capture the cross-scale semantic correlation of RS objects. In the boundary branch, we propose a Multiscale Boundary Feature Extraction (MBFE) module that utilizes atrous convolutions with different dilation rates to extract multi-scale boundary features. Finally, to address the problem of sparse boundary pixels in the fusion process of the two branches, we propose a Multi-scale Similarity-guided Aggregation (MSA) module by calculating the similarity of semantic features and boundary features at the corresponding scale, which can emphasize the boundary information in semantic features. Our proposed CGIN outperforms state-of-the-art approaches in numerical experiments conducted on two benchmark remote sensing datasets. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
35. Microstructure and properties of FeCoNiCrMn and Al2O3 hybrid particle-reinforced aluminum matrix composites fabricated by microwave sintering
- Author
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H.M. Wang, W.X. Su, J.Q. Liu, G.R. Li, Y.J. Liu, and P.J. Zhou
- Subjects
Aluminum matrix composite ,Hybrid reinforced ,High entropy alloy ,Cross-scale ,Mechanical properties ,Mining engineering. Metallurgy ,TN1-997 - Abstract
In this paper, multiscale Al2O3 micro/nanoparticles (0–14 wt%) mixed with FeCoNiCrMn high-entropy alloy (HEA) particles (15 wt%) were used as reinforcements to prepare dual-phase-reinforced aluminum matrix composites (AMCs) through microwave sintering. The strengthening effects of doping different weight fractions of Al2O3 micro/nanoparticles on the microstructure, mechanical properties, and strengthening mechanisms of the mixed-phase particle-reinforced AMCs were investigated. The performance after 11 wt% Al2O3+HEA microparticles was similar to that obtained by adding 2 wt% and 5 wt% Al2O3+HEA nanoparticles. The hardness, yield strength, and compressive strength of the 2 wt% nano-Al2O3 composite were 109.7 HV, 286.5 MPa, and 506.7 MPa, respectively, which were 70.9%, 98.5%, and 94.7% higher than those of the single HEA-reinforced sample. In terms of the strengthening and toughening mechanisms, Orowan strengthening, dislocation strengthening, and thermal mismatch strengthening were the main strengthening mechanisms of particles species mixed in the metal matrix composites. Hall-Petch strengthening and load-transfer effects were mainly attributed to the cross-scale mixing of particles. The hybrid particles of HEA and Al2O3 synergistically delayed interfacial crack propagation. This study provides a new preparation method for high-performance metal matrix composites.
- Published
- 2023
- Full Text
- View/download PDF
36. Cross-Scale Modeling of Shallow Water Flows in Coastal Areas with an Improved Local Time-Stepping Method
- Author
-
Guilin Liu, Tao Ji, Guoxiang Wu, Hao Tian, and Pubing Yu
- Subjects
shallow water model ,local time-stepping ,cross-scale ,computational efficiency ,Naval architecture. Shipbuilding. Marine engineering ,VM1-989 ,Oceanography ,GC1-1581 - Abstract
A shallow water equations-based model with an improved local time-stepping (LTS) scheme is developed for modeling coastal hydrodynamics across multiple scales, from large areas to detailed local regions. To enhance the stability of the shallow water model for long-duration simulations and at larger LTS gradings, a prediction-correction method using a single-layer interface that couples coarse and fine time discretizations is adopted. The proposed scheme improves computational efficiency with an acceptable additional computational burden and ensures accurate conservation of time truncation errors in a discrete sense. The model performance is verified with respect to conservation and computational efficiency through two idealized tests: the spreading of a drop of shallow water and a tidal flat/channel system. The results of both tests demonstrate that the improved LTS scheme maintains precision as the LTS grading increases, preserves conservation properties, and significantly improves computational efficiency with a speedup ratio of up to 2.615. Furthermore, we applied the LTS scheme to simulate tides at grid scales of 40,000 m to 200 m for a portion of the Northwest Pacific. The proposed model shows promise for modeling cross-scale hydrodynamics in complex coastal and ocean engineering problems.
- Published
- 2024
- Full Text
- View/download PDF
37. Neighbourhood landscape context shapes local species richness patterns across continents.
- Author
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Li, Lihe, Teng, Shuqing N., Zhang, Yong, Li, Yuxiang, Wang, Haijun, Santana, Joana, Reino, Luís, Abades, Sabastián, Svenning, Jens‐Christian, and Xu, Chi
- Subjects
- *
SPECIES diversity , *LANDSCAPE ecology , *GRID cells , *LANDSCAPES , *NEIGHBORHOODS - Abstract
Aim: Recent studies highlight the importance of linking landscape ecology and macroecology for a better understanding of broad‐scale biodiversity patterns. The "landscape context effect" denotes that species responses and biodiversity in a focal area are shaped by neighbouring landscape composition and structure outside the focal area. Here, we test whether the landscape context effect could be pronounced at macroecological scales. Location: Sub‐Saharan Africa and continental China. Time period: Late 20th to early 21st centuries. Taxa studied: Terrestrial mammals (≥2 kg). Methods: We calculated species richness on the basis of grid cells of 50 km × 50 km and 100 km × 100 km. We used ordinary least square and random forest models to examine the relationships between species richness within grid cells and landscape context (defined as composition and structure of the neighbouring landscape outside the grid cells, with distances of 10–400 km to the boundary of a given grid cell). We used variation partitioning to quantify the independent and shared explanatory power of the landscape context variables, grouping species by body size and diet. Results: Landscape context alone explained ≤20% of the variation in species richness, even when controlling for correlations with macroenvironmental variables (climate, productivity and topography) and correlations with landscape attributes within the grid cells. Importantly, the explanatory power of landscape context at the scales of 100–400 km ofen outweighed grid‐cell landscape attributes or macro‐environmental variables. The independent explanatory power of landscape context was lowest for small‐sized omnivores. Furthermore, we found higher independent explanatory power for large herbivores in sub‐Saharan Africa than in continental China. Main conclusions: Landscape context plays a substantial role in shaping local biodiversity patterns at regional and continental scales, with its strength varying with organism diet and movement needs and possibilities. These findings support that conservation efforts should include effective management of landscape structure, with attention to differing space requirements among organism groups. Our work also illustrates the scope for testing landscape ecological hypotheses at macroecological scales. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
38. Sustainable biopolymer soil stabilisation: the effect of microscale chemical characteristics on macroscale mechanical properties.
- Author
-
Armistead, Samuel J., Smith, Colin C., and Staniland, Sarah S.
- Subjects
- *
LOCUST bean gum , *BIOPOLYMERS , *METHYLCELLULOSE , *GUAR gum , *POWER transmission - Abstract
Sustainable biopolymer additives offer a promising soil stabilisation methodology, with a strong potential to be tuned to soil's specific nature, allowing the tailoring of mechanical properties for a range of geotechnical applications. However, the biopolymer chemical characteristics driving soil mechanical property modifications have yet to be fully established. Within this study we employ a cross-scale approach, utilising the differing galactose:mannose (G:M) ratios of various Galactomannan biopolymers (Guar Gum G:M 1:2, Locust Bean Gum G:M 1:4, Cassia Gum G:M 1:5) to investigate the effect of microscale chemical functionality upon macroscale soil mechanical properties. Molecular weight effects are also investigated, utilising Carboxy Methyl Cellulose (CMC). Soil systems comprising of SiO2 (100%) (SiO2) and a Mine Tailing (MT) exemplar composed of SiO2 (90%) + Fe2O3 (10%) (SiO2 + Fe) are investigated. The critical importance of biopolymer additive chemical functionality for the resultant soil mechanical properties, is demonstrated..For Galactomannan G:M 1:5 stabilised soils the 'high-affinity, high-strength', mannose-Fe interactions at the microscale (confirmed by mineral binding characterisation) are attributed to the 297% increase in the SiO2 + Fe systems Unconfined Compressive Strength (UCS), relative to SiO2 only. Conversely for SiO2 Galactomannan-stabilised soils, when increasing the G:M ratio from 1:2 to 1:5, a 85% reduction in UCS is observed, attributed to mannose's inability to interact with SiO2. UCS variations of up to a factor of 12 were observed across the biopolymer–soil mixes studied, in line with theoretically and experimentally expected values, due to the differences in the G:M ratios. The limited impact of molecular weight upon soil strength properties is also shown in CMC-stabilised soils. When considering a soil's stiffness and energy absorbance, the importance of biopolymer–biopolymer interaction strength and quantity is discussed, further deciphering biopolymer characteristics driving soil property modifications. This study highlights the importance of biopolymer chemistry for biopolymer stabilisation studies, illustrating the use of simple low-cost, accessible chemistry-based instrumental tools and outlining key design principles for the tailoring of biopolymer–soil composites for specific geotechnical applications. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
39. Plant α‐and β‐diversity, and soil microbial stoichiometry co‐regulate the alterations in ecosystem multifunctionality in response to grazing and N addition in a typical steppe.
- Author
-
Li, Lan, Wang, Mengyuan, He, Xiong Zhao, Wang, Zhen, Zhang, Xiumin, Hu, Junqi, Huang, Ling, and Hou, Fujiang
- Subjects
GRASSLAND conservation ,GRAZING ,STEPPES ,ECOSYSTEMS ,STOICHIOMETRY ,MENTAL arithmetic - Abstract
Despite their significance, how interactions of plant diversity at multiple spatial scales and soil microbial stoichiometry alter a series of ecosystem functions (multifunctionality, EMF) in response to anthropogenic nitrogen (N) input and herbivores are poorly known. We conducted a 17‐year sheep grazing experiment with 6‐year N addition to explore the impacts of grazing (0, 2.7, 5.3 and 8.7 sheep ha−1) and N addition (N0, N5, N10 and N20, i.e., 0, 5, 10 and 20 g N m−2 yr−1, respectively) on grassland functions and EMF via changes in plant α‐and β‐diversity, and carbon to nitrogen ratio (C:N) of soil microbes in a typical steppe. The results show that grazing or N addition alone significantly affected EMF with a treatment order of 2.7 and 8.7 sheep ha−1 > 0 and 5.3 sheep ha−1 for grazing intensity or N5 > N10 and N20 > N0 for N addition, which resulted in a significant higher EMF in the combination treatment of 2.7 sheep ha−1 and 5 g N m−2 yr−1. Plant α‐and β‐diversity, and soil microbial C:N were the predominant drivers of changes in EMF. Grazing reduced EMF indirectly by decreasing the plant β‐diversity. N addition promoted EMF indirectly by decreasing plant α‐diversity. In addition, lower plant α‐diversity enhanced EMF indirectly by increasing soil microbial C:N. Our results suggest that the negative effects of herbivore on EMF were stronger at larger spatial scales compared to the smaller local communities, while N addition could maintain a higher level of EMF at smaller scales rather than at the larger ones. Our results highlight that multiple spatial scales should be considered to fully unravel the effects of herbivore and eutrophication on ecosystem functions. Our results also demonstrate the important role of soil microbe in maintaining higher grassland multifunctionality, thus we should include the soil microbial functions (i.e., C and N transformation) in further studies. Our results suggest that grazing at a low grazing intensity of 2.7 sheep ha−1 with a low N supplementation of 5 g N m−2 yr−1 could maintain the most important ecosystem functions. Our work provides important insight into grassland conservation and management, aiming to maintain the capacity of grasslands to sustainably supply ecological and productive functions. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
40. Cross-scale content-based full Transformer network with Bayesian inference for object tracking.
- Author
-
Fan, Shenghua, Chen, Xi, He, Chu, Huang, Yan, and Chen, Kehan
- Subjects
OBJECT tracking (Computer vision) ,CONVOLUTIONAL neural networks ,BAYESIAN field theory ,BAYESIAN analysis ,CONDITIONAL probability - Abstract
Visual tracking is fundamentally the problem of conditional probability regressing of the target location in each video frame. Convolutional neural network (CNN) have been dominant in visual tracking these years, but CNN-based trackers neglect long-range dependency in likelihood representation and prior information, these destroy the spatial consistency of target. Recently emerging Transformer-based trackers mitigate these, however, they do not possess the ability to build interactions among features of cross-scale. Moreover, the sine position encoding prior in Transformer-based tracker is content-unaware and fails to reflect the relative index of different positions. To address these issues and inspired by Bayesian probabilistic formulation, we propose a cross-scale full Transformer tracker with content-based prior bias (named BTT). There are four main contributions of the method, (i) we propose a hierarchical full Transformer tracking architecture to introduce long-range dependency, which enriches the likelihood representation of model, and alleviates the destruction of spatial consistency. (ii) An expanding layer without using convolution or interpolation operation is proposed to aggregate layer information of different scales to construct cross-scale likelihood estimation. (iii) We further demonstrate the defect of sine position encoding with mathematical derivation, and introduce a content-based positional encoding bias as prior in the Transformer architecture to reflect the relative index of inputs. (iv) And extensive experiments show that the proposed tracker achieves better performance compared with CNN-based trackers in cases of illumination, low resolution, deformation on various datasets, and achieves superior performance on others attributes. The proposed tracker obtains 70.3%, 69.1%, 63.4% on OTB2015, UAV123, and LaSOT, respectively. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
41. Determining the mechanical parameters of asteroid rocks using NWA13618 meteorites and microscale rock mechanics experiment
- Author
-
TANG Xu-hai, XU Jing-jing, ZHANG Yi-heng, HE Qi, WANG Zheng-zhi, ZHANG Guo-ping, and LIU Quan-sheng
- Subjects
space mining ,extraterrestrial rock mechanics ,nanoindentation ,asteroid rock ,meteorite ,cross-scale ,Engineering geology. Rock mechanics. Soil mechanics. Underground construction ,TA703-712 - Abstract
In the future, the extraterrestrial human activities, such as resources exploitation and base construction beyond the Earth need the aid of geotechnical engineering technology. Currently, there are only two approaches for humans to obtain the rock samples beyond the Earth: sample-return activities by spacecraft and meteorite investigation. Meteorites are rare, expensive, small and arbitrary in shape, so it is difficult to process them into standard rock samples required by MTS and other traditional macroscale rock mechanical tests. In this paper, a novel technique for measuring mechanical property of small-size meteorites was developed based on microscale rock mechanics experiments (micro-RME) and statistical probability models. Firstly, the composition, content and distribution of rock-forming minerals in NWA13618 meteorites were obtained by TIMA. Then, Gaussian mixture model was used to calculate the mechanical parameters of four main minerals in meteorite NWA13618. The elastic moduli of olivine, pyroxene, Fe-Ni and feldspar are 116.73, 101.77, 87.24 and 70.74 GPa, respectively. Lastly, the homogenization method Mori-Tanaka model isapplied to calculate the macroscale centimeter elastic modulus of NWA13618 meteorite is 90.48 GPa according to the achieved mineral content and mechanical properties. The microscale rock mechanical experiment and scale upgrading method proposed in this paper provide theoretical basis and technical means for predicting the mechanical properties of L4 parent asteroid.
- Published
- 2022
- Full Text
- View/download PDF
42. From polyps to pixels: understanding coral reef resilience to local and global change across scales.
- Author
-
Donovan, Mary K., Alves, Catherine, Burns, John, Drury, Crawford, Meier, Ouida W., Ritson-Williams, Raphael, Cunning, Ross, Dunn, Robert P., Goodbody-Gringley, Gretchen, Henderson, Leslie M., Knapp, Ingrid S. S., Levy, Joshua, Logan, Cheryl A., Mudge, Laura, Sullivan, Chris, Gates, Ruth D., and Asner, Gregory P.
- Subjects
CORAL reefs & islands ,CORALS ,CORAL declines ,TECHNOLOGICAL innovations ,CORAL bleaching ,CORAL reef restoration - Abstract
Context: Coral reef resilience is the product of multiple interacting processes that occur across various interacting scales. This complexity presents challenges for identifying solutions to the ongoing worldwide decline of coral reef ecosystems that are threatened by both local and global human stressors. Objectives: We highlight how coral reef resilience is studied at spatial, temporal, and functional scales, and explore emerging technologies that are bringing new insights to our understanding of reef resilience. We then provide a framework for integrating insights across scales by using new and existing technological and analytical tools. We also discuss the implications of scale on both the ecological processes that lead to declines of reefs, and how we study those mechanisms. Methods: To illustrate, we present a case study from Kāneʻohe Bay, Hawaiʻi, USA, linking remotely sensed hyperspectral imagery to within-colony symbiont communities that show differential responses to stress. Results: In doing so, we transform the scale at which we can study coral resilience from a few individuals to entire ecosystems. Conclusions: Together, these perspectives guide best practices for designing management solutions that scale from individuals to ecosystems by integrating multiple levels of biological organization from cellular processes to global patterns of coral degradation and resilience. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
43. Improved Complementary Pulmonary Nodule Segmentation Model Based on Multi-Feature Fusion.
- Author
-
Tang, Tiequn, Li, Feng, Jiang, Minshan, Xia, Xunpeng, Zhang, Rongfu, and Lin, Kailin
- Subjects
- *
PULMONARY nodules , *LUNGS , *CONVOLUTIONAL neural networks , *LUNG cancer , *COMPUTED tomography - Abstract
Accurate segmentation of lung nodules from pulmonary computed tomography (CT) slices plays a vital role in the analysis and diagnosis of lung cancer. Convolutional Neural Networks (CNNs) have achieved state-of-the-art performance in the automatic segmentation of lung nodules. However, they are still challenged by the large diversity of segmentation targets, and the small inter-class variances between the nodule and its surrounding tissues. To tackle this issue, we propose a features complementary network according to the process of clinical diagnosis, which made full use of the complementarity and facilitation among lung nodule location information, global coarse area, and edge information. Specifically, we first consider the importance of global features of nodules in segmentation and propose a cross-scale weighted high-level feature decoder module. Then, we develop a low-level feature decoder module for edge feature refinement. Finally, we construct a complementary module to make information complement and promote each other. Furthermore, we weight pixels located at the nodule edge on the loss function and add an edge supervision to the deep supervision, both of which emphasize the importance of edges in segmentation. The experimental results demonstrate that our model achieves robust pulmonary nodule segmentation and more accurate edge segmentation. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
44. A Numerical Study of Hypoxia in Chesapeake Bay Using an Unstructured Grid Model: Validation and Sensitivity to Bathymetry Representation.
- Author
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Cai, Xun, Zhang, Yinglong J., Shen, Jian, Wang, Harry, Wang, Zhengui, Qin, Qubin, and Ye, Fei
- Subjects
- *
HYPOXIA (Water) , *SALTWATER encroachment , *MODEL validation , *BATHYMETRY , *WATER quality , *HYPOXEMIA , *CHLOROPHYLL - Abstract
A three‐dimensional unstructured‐grid hydrodynamic and water quality model (Semi‐implicit Cross‐scale Hydroscience Intergrated System Model‐Integrated Compartment Model) is applied successfully for Chesapeake Bay. The model is validated with observations of salinity, chlorophyll‐a, dissolved oxygen, nutrients, and phytoplankton productions from the year 1991 to 1995 for the mainstem and some major tributaries, based on multiple model skill scores. Model experiments are conducted to test the importance of having (1) an accurate representation of bathymetry to correctly predict hypoxia and other processes and (2) a high‐resolution model grid for tributaries to correctly simulate water quality variables. Comparison with the model experiment results with bathymetry smoothing indicates that bathymetry smoothing, as commonly used for many systems, changes the stratification and lateral circulation pattern, resulting in more salt intrusion into shallow water regions, and an increase in the freshwater age. Consequently, a model with bathymetry smoothing can lead to an unrealistic prediction of the distribution of hypoxia and phytoplankton production. Local grid refinement shows significant improvement of model simulations on local stratification and water quality variables. Overall, the use of high‐resolution unstructured grid model leads to a faithful representation of the complex geometry, and thus a seamless cross‐scale capability for simulating water quality processes in the Bay including tributaries and tidal creeks. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
45. A Cross-Scale Framework for Modelling Chloride Ions Diffusion in C-S-H: Combined Effects of Slip, Electric Double Layer and Ion Correlation.
- Author
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Qi, Yunchao, Peng, Weihong, Zhang, Wei, Jing, Yawen, and Hu, Liangyu
- Subjects
- *
ELECTRIC double layer , *CHLORIDE ions , *CHLORIDE channels , *SOLID-liquid interfaces , *CONCRETE durability , *IONS , *PORE size distribution - Abstract
Water and chloride ions within pores of cementitious materials plays a crucial role in the damage processes of cement pastes, particularly in the binding material comprising calcium-silicate-hydrates (C-S-H). The migration mechanism of water and chloride ions restricted in C-S-H nanopores is complicated due to the presence of interfacial effects. The special mechanical properties of the solid–liquid interface determine the importance of boundary slip and Electric Double Layer (EDL) and ion diversity in pore solutions determines the difference of the EDL and the stability of water film slip. A cross-scale model covering slip effects, time-varying of EDL and ion correlation needs to be developed so that the interfacial effects concentrated at the pore scale can be extended to affect the overall diffusivity of C-S-H. The statistics of pore size distribution and fractal dimension were used to quantitatively compare the similarities between model and C-S-H structure, thus proving the reliability of cross-scale reconstructed C-S-H transmission model. The results show that the slip effect is the dominant factor affecting the diffusion ability of C-S-H, the contribution of the slip effect is up to 60% and the contribution rate of EDL time-varying only up to about 15%. Moreover, the slip effect is sensitive to both ion correlation and C-S-H inhomogeneity and EDL time-varying is almost insensitive to ion correlation changes. This quantification provides a necessary benchmark for understanding the destructiveness of cement-based materials in the salt rich environment and provides new insights into improving the durability of concrete by changing the solid–liquid interface on the micro-nanoscale. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
46. Cross-scale energy transfer of chaotic oscillator chain in stiffness-dominated range.
- Author
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Chen, Jian-en, Sun, Min, Zhang, Wei, Li, Shuang-bao, and Wu, Rui-qin
- Abstract
The investigations on the dynamics of hierarchical oscillator chains provide basic theories for the fields of acoustic metamaterial and passive guidance of energy flow. In the present study, the characteristics of stiffness-dominated energy transfer of a reduced cross-scale oscillator chain that generates chaotic vibrations are studied. The semi-analytical solutions are obtained by the complexification-averaging method and the least-square method for thoroughly searching the branches of responses. Then, the energy transfer patterns of the oscillator chain are analyzed based on Runge–Kutta method. Moreover, chaotic responses are determined using the displacements and Lyapunov exponents of the system. The average energy and normalized energy flux are defined to evaluate the energy distribution in each oscillator and the energy transfer between oscillators, respectively. The semi-analytical results show that the oscillator chain produces complex unstable branches of response around the resonance frequency of the linear oscillator. It is found that the detached higher branches of response of the chain are similar to that of a system consisting of one linear oscillator and one cubic oscillator. When chaotic responses occur, the energy transfer patterns that reflected by average energy and normalized energy flux are similar in the same branch of response for different excitation frequencies. However, energy transfer patterns in different branches of response are quite different even at the same excitation frequency, and the higher branch generates the lower energy transfer. Furthermore, analyses of the input energy and the scale between cubic oscillators demonstrate that variations of the two parameters slightly affect the normalized energy flux. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
47. Micro-feature-motivated numerical analysis of the coupled bio-chemo-hydro-mechanical behaviour in MICP.
- Author
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Wang, Xuerui and Nackenhorst, Udo
- Subjects
- *
NUMERICAL analysis , *LITERARY sources , *PERMEABILITY , *GEOMETRIC modeling , *CALCITE - Abstract
A coupled bio-chemo-hydro-mechanical model (BCHM) is developed to investigate the permeability reduction and stiffness improvement in soil by microbially induced calcite precipitation (MICP). Specifically, in our model based on the geometric method a link between the micro- and macroscopic features is generated. This allows the model to capture the macroscopic material property changes caused by variations in the microstructure during MICP. The developed model was calibrated and validated with the experimental data from different literature sources. Besides, the model was applied in a scenario simulation to predict the hydro-mechanical response of MICP-soil under continuous biochemical, hydraulic and mechanical treatments. Our modelling study indicates that for a reasonable prediction of the permeability reduction and stiffness improvement by MICP in both space and time, the coupled BCHM processes and the influences from the microstructural aspects should be considered. Due to its capability to capture the dynamic BCHM interactions in flexible settings, this model could potentially be adopted as a designing tool for real MICP applications. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
48. Feature-transferable Pyramid Network for Cross-scale Object Detection in SAR Images
- Author
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Zheng ZHOU, Zongyong CUI, Zongjie CAO, and Jianyu YANG
- Subjects
sar object detection ,feature pyramid ,feature-transfer ,dilated convolution group ,cross-scale ,Electricity and magnetism ,QC501-766 - Abstract
Multiscale object detection in Synthetic Aperture Radar (SAR) images can locate and recognize key objects in large-scene SAR images, and it is one of the key technologies in SAR image interpretation. However, for the simultaneous detection of SAR objects with large size differences, that is, cross-scale object detection, existing object detection methods are difficult to extract the features of cross-scale objects, and also difficult to realize cross-scale object simultaneous detection. In this study, we propose a multiscale object detection method based on the Feature-Transferable Pyramid Network (FTPN) for SAR images. In the feature extraction stage, the feature migration method is used to obtain an effective mosaic of the feature images of each layer and extract feature images with different scales. Simultaneously, the void convolution method is used to increase the receptive field of feature extraction and aid the network in extracting large object features. These steps can effectively preserve the features of objects of different sizes, to realize the simultaneous detection of cross-scale objects in SAR images. The experiments based on the GaoFen-3 SAR dataset, SAR Ship Detection Dataset (SSDD), and high-resolution SSDD-2.0 show that the proposed method can detect cross-scale objects, such as airports and ships in SAR images, and the mean Average Precision (mAP) can reach 96.5% on the existing dataset, which is 8.1% higher than that of the characteristic pyramid network algorithm. Moreover, the overall performance of the proposed method is better than that of the latest YOLOv4 and other object detection algorithms.
- Published
- 2021
- Full Text
- View/download PDF
49. A cross-scale indicator framework for the study of annual stability of land surface temperature in different land uses.
- Author
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Zhang, Shuyang, Yuan, Chao, Chen, Taihan, Ma, Beini, and Liu, Nianxiong
- Subjects
LAND surface temperature ,URBAN land use ,URBAN heat islands ,URBAN planning ,LAND cover - Abstract
• Establish an indicator framework for ΔLST in regions with large seasonal differences. • Reveal the impact of land characteristics on ΔLST under the same land use. • The ratio of green land to other land uses has an interactive effect on ΔLST. • Maintain GSR at a minimum of 24 % for residential land and 23 % for office land. • FAR for residential and office land has a nonlinear effect on ΔLST. Urban Land Surface Temperature (LST) is crucial in surface urban heat island (SUHI) and microclimate studies. Currently, research has focused on seasonal LST differences across land uses, but annual LST fluctuations (ΔLST) within the same land use and their drivers remain underexplored. To explore the impact of land characteristics and urban elements on seasonal LST differences, we propose annual LST stability. We constructed a new indicator framework based on Land Use and Land Cover (LULC), supplemented by Land Morphology (LM) and Land Properties (LP), for cross-scale ΔLST research. We identified land use ratios and key characteristics of urban plots with high stability. The results show an interactive effect of the green land ratio to other land on ΔLST. For residential and office land, the green space ratio (GSR) is key to annual LST stability. Residential land needs a GSR of more than 24 %. The floor area ratio (FAR) for residential and office land has a significant nonlinear effect on annual LST stability, with FARs of 1.8 for residential land and 1.5 for office land being most detrimental to the LST stability. For practical implications, we conducted cluster analyses on residential, office, and green lands, providing strategies to improve stability. These conclusions help balance land economic benefits with urban climate resilience and guide urban planning and design to address the challenges of heat and cold waves. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
50. A Study of the Critical Velocity of the Droplet Transition from the Cassie to Wenzel State on the Symmetric Pillared Surface.
- Author
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Wu, Zhulong, Li, Yingqi, Cui, Shaohan, Li, Xiao, Zhou, Zhihong, and Tian, Xiaobao
- Subjects
- *
CRITICAL velocity , *STATIC equilibrium (Physics) , *SUPERHYDROPHOBIC surfaces , *SURFACE properties , *SURFACE dynamics - Abstract
A droplet hitting a superhydrophobic surface will undergo the Cassie to Wenzel transition when the wetting force exceeds the anti-wetting force. The critical velocity of the droplet's Cassie to Wenzel state transition can reflect the wettability of the surface. However, the critical velocity research is still at the microscale and has not been extended to the nanoscale mechanism. A cross-scale critical velocity prediction model for superhydrophobic surfaces with symmetric structures is proposed here based on a mechanical equilibrium system. The model's applicability is verified by experimental data. It demonstrates that the mechanical equilibrium system of droplet impact with capillary pressure and Laplace pressure as anti-wetting forces is more comprehensive, and the model proposed in this study predicts the critical velocity more precisely with a maximum error of 12% compared to the simulation results. Furthermore, the correlation between the simulation at the nanoscale and the evaluation of the macroscopic symmetrical protrusion surface properties is established. Combined with the model and the correlation, the relationship between the microscopic mechanism and the macroscopic examination of droplet dynamics on the superhydrophobic surface be presented, and the wettability evaluation method of macroscopic surfaces based on the molecular simulation mechanism can be realized. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
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