In contrast to the composition uniformity of homogeneous materials, heterogeneous materials are normally composed of two or more distinctive constituents. It is usually recognized that the effective material property ...
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In contrast to the composition uniformity of homogeneous materials, heterogeneous materials are normally composed of two or more distinctive constituents. It is usually recognized that the effective material property of a heterogeneous material is related to the mechanical property and the distribution pattern of each forming constituent. However, to establish an explicit relationship between the macroscale mechanical property and the microstructure appears to be complicated. On the other hand, machine learning methods are broadly employed to excavate inherent rules and correlations based on a significant amount of data samples. Specifically, deep neural networks are established to deal with situations where input-output mappings are extensively complex. In this paper, a method is proposed to establish the implicit mapping between the effective mechanical property and the mesoscale structure of heterogeneous materials. Shale is employed in this paper as an example to illustrate the method. At the mesoscale, a shale sample is a complex heterogeneous composite that consists of multiple mineral constituents. The mechanical properties of each mineral constituent vary significantly, and mineral constituents are distributed in an utterly random manner within shale samples. Large quantities of shale samples are generated based on mesoscale scanning electron microscopy images using a stochastic reconstruction algorithm. imageprocessing techniques are employed to transform the shale sample images to finite element models. Finite element analysis is utilized to evaluate the effective mechanical properties of the shale samples. A convolutional neural network is trained based on the images of stochastic shale samples and their effective moduli. The trained network is validated to be able to predict the effective moduli of real shale samples accurately and efficiently. Not limited to shale, the proposed method can be further extended to predict effective mechanical properties o
Unmanned aerial vehicles (UAVs), or drones, have become an integral part of diverse civil and commercial applications. But illegal operations of UAVs pose serious risks to public safety, privacy and national security....
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Previous methods utilize the neural Radiance Field (NeRF) for panoptic lifting, while their training and rendering speed are unsatisfactory. In contrast, 3D Gaussian Splatting (3DGS) has emerged as a prominent techniq...
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Previous methods utilize the neural Radiance Field (NeRF) for panoptic lifting, while their training and rendering speed are unsatisfactory. In contrast, 3D Gaussian Splatting (3DGS) has emerged as a prominent technique due to its rapid training and rendering speed. However, unlike NeRF, the conventional 3DGS may not satisfy the basic smoothness assumption as it does not rely on any parameterized structures to render (e.g., MLPs). Consequently, the conventional 3DGS is, in nature, more susceptible to noisy 2D mask supervision. In this paper, we propose a new method called PLGS that enables 3DGS to generate consistent panoptic segmentation masks from noisy 2D segmentation masks while maintaining superior efficiency compared to NeRF-based methods. Specifically, we build a panoptic-aware structured 3D Gaussian model to introduce smoothness and design effective noise reduction strategies. For the semantic field, instead of initialization with structure from motion, we construct reliable semantic anchor points to initialize the 3D Gaussians. We then use these anchor points as smooth regularization during training. Additionally, we present a self-training approach using pseudo labels generated by merging the rendered masks with the noisy masks to enhance the robustness of PLGS. For the instance field, we project the 2D instance masks into 3D space and match them with oriented bounding boxes to generate cross-view consistent instance masks for supervision. Experiments on various benchmarks demonstrate that our method outperforms previous state-of-the-art methods in terms of both segmentation quality and speed.
Pan-sharpening is a domain-specific task of satellite imagery fusion. However, most traditional methods fuse the panchromatic image and the multispectral images in linear manners, which lead to severe spectral and spa...
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Pan-sharpening is a domain-specific task of satellite imagery fusion. However, most traditional methods fuse the panchromatic image and the multispectral images in linear manners, which lead to severe spectral and spatial distortions. In the meanwhile, discriminative learning methods are limited in specialized satellites and tasks. In this paper, we make an attempt to integrate a deep prior with model-based optimization scheme for pan-sharpening. The proposed deep prior is based on a convolutional neural network which is composed of the proposed problem-specific recursive block and is trained in gradient domain. We plug the trained prior in place of the spatial preservation term in model-based optimization scheme, and address it with the alternating direction method of multipliers. Final experimental results demonstrate that the proposed model can overcome the restriction of linear model, and greatly reduce spectral and spatial distortions. Compared with several discriminative learning methods, our model tends to achieve promising generalization across different satellites.
Context. Point source (PS) detection is an important issue for future cosmic microwave background (CMB) experiments since they are one of the main contaminants to the recovery of CMB signal on small scales. Improving ...
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Context. Point source (PS) detection is an important issue for future cosmic microwave background (CMB) experiments since they are one of the main contaminants to the recovery of CMB signal on small scales. Improving its multi-frequency detection would allow us to take into account valuable information otherwise neglected when extracting PS using a channel-by-channel approach. Aims. We aim to develop an artificial intelligence method based on fully convolutional neural networks to detect PS in multi-frequency realistic simulations and compare its performance against one of the most popular multi-frequency PS detection methods, the matrix filters. The frequencies used in our analysis are 143, 217, and 353 GHz, and we imposed a Galactic cut of 30 degrees. methods. We produced multi-frequency realistic simulations of the sky by adding contaminating signals to the PS maps as the CMB, the cosmic infrared background, the Galactic thermal emission, the thermal Sunyaev-Zel'dovich effect, and the instrumental and PS shot noises. These simulations were used to train two neural networks called flat and spectral MultiPoSeIDoNs. The first one considers PS with a flat spectrum, and the second one is more realistic and general because it takes into account the spectral behaviour of the PS. Then, we compared the performance on reliability, completeness, and flux density estimation accuracy for both MultiPoSeIDoNs and the matrix filters. Results. Using a flux detection limit of 60 mJy, MultiPoSeIDoN successfully recovered PS reaching the 90% completeness level at 58 mJy for the flat case, and at 79, 71, and 60 mJy for the spectral case at 143, 217, and 353 GHz, respectively. The matrix filters reach the 90% completeness level at 84, 79, and 123 mJy. To reduce the number of spurious sources, we used a safer 4 sigma flux density detection limit for the matrix filters, the same as was used in the Planck catalogues, obtaining the 90% of completeness level at 113, 92, and 398 mJy. In all
The accurate prediction of received signal strength (RSS) is the key to coverage optimization and interference management in network planning, as well as proactive resource allocation and anticipated network managemen...
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ISBN:
(纸本)9781665423915
The accurate prediction of received signal strength (RSS) is the key to coverage optimization and interference management in network planning, as well as proactive resource allocation and anticipated network management. Traditional methods for RSS prediction are based on ray tracing or stochastic radio propagation model. The former requires the detailed 3D geometry and dielectric properties of the reflectors, which may not be available practically. The latter roughly classify the environment as either urban, suburban and rural scenarios and does not make full use of the environment information. In this paper, by leveraging accessible satellite maps to capture the features of radio environment, a distributed federated learning (FL) RSS prediction framework is proposed to fully exploit the user generated real-time data while preserving the users’ privacy. To further improve the prediction accuracy, the deep vision transformer (DeepVIT) is utilized to process the images of the satellite map, because it is capable of learning to "pay attention to" important parts of an image such as reflection surfaces and blockages. The proposed method is evaluated by the real-world data set including around 60, 000 individual measurements. Simulations results verified that the prediction accuracy of the proposed method outperforms baseline methods including ray tracing, Urban Macro (UMa) model and convolutional neural network (CNN) based method. Moreover, the computational time is reduced five times compared with CNN based method.
Super-resolution localization microscopy (SRLM) techniques overcome the diffraction limit, making possible the observation of sub-cellular structures in vivo. At present, the spatial resolution of similar to 20 nm in ...
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ISBN:
(纸本)9781510630987
Super-resolution localization microscopy (SRLM) techniques overcome the diffraction limit, making possible the observation of sub-cellular structures in vivo. At present, the spatial resolution of similar to 20 nm in x-y axis has been achieved in SRLM. However, the localization accuracy for the longitudinal axis (i.e., the z-axis) still need be improved. Although some methods have been proposed to implement 3-D SRLM, these methods are computationally intensive and parameter dependent. To overcome these limitations, in this paper, we propose a new method based on deep learning, termed as dl-3D-SRLM. By learning the mapping between a 2-D camera frame (i.e., the experimentally acquired image) and the true 3-D locations of fluorophores in the corresponding image region with a convolutional neural network (CNN), dl-3D-SRLM provides the possibility of implementing 3-D SRLM with a high localization accuracy, a fast data-processing speed, and a little human intervention. To evaluate the performance of dl-3D-SRLM, a series of numerical simulations are performed. The results show that when using dl-3D-SRLM, we can accurately resolve the 3-D location of fluorophores from the acquired 2-D images, even if under high fluorophores densities and low signal-to-noise ratio conditions. In addition, the complex 3-D structure can also be effectively imaged by dl-3D-SRLM. As a result, dl-3D-SRLM is more beneficial for 3D-SRLM imaging.
Row detection in agricultural applications has commonly used Hough transform techniques and traditional signalprocessing based approaches relating to machine vision. There are various learning based methods available...
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The stripe noise effects severely degrade the image quality in infrared imaging systems. The existing destriping algorithms still struggle to balance noise suppression, detail preservation, and real-time performance, ...
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The stripe noise effects severely degrade the image quality in infrared imaging systems. The existing destriping algorithms still struggle to balance noise suppression, detail preservation, and real-time performance, which retards their application in spectral imaging and signalprocessing field. To solve this problem, an innovative wavelet deep neural network from the perspective of transform domain is presented in this paper, which takes the intrinsic characteristics of stripe noise and complementary information between the coefficients of different wavelet sub-bands into full consideration to accurately estimate the noise with the lower computational load. In addition, a special directional regularizer is further defined to separate the scene details from stripe noise more thoroughly and recover the details more accurately. The extensive experiments on simulated and real data demonstrate that our proposed method outperforms several classical destriping methods on both quantitative and qualitative assessments.
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