Databases of 3D CAD (computer aided design) models are often large and lacking in meaningful organisation. Effective tools for automatically searching for, categorising and comparing CAD models, therefore, have many p...
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Databases of 3D CAD (computer aided design) models are often large and lacking in meaningful organisation. Effective tools for automatically searching for, categorising and comparing CAD models, therefore, have many potential applications in improving efficiency within design processes. This paper presents a novel asymmetric autoencoder model, consisting of a recursive encoder network and fully-connected decoder network, for the reproduction of CAD models through prediction of the parameters necessary to generate a 3D part design. Inputs to the autoencoder are STEP (standard for the exchange of product data) files, an ISO standard CAD model format, compatible with all major CAD software. A complete 3D model can be accurately reproduced using a STEP file, meaning that all geometric information can be used to contribute to the final encoded vector, with no loss of small detail. In a CAD model of overall size 10 x 10 x 10 units, for 90% of models, the class of an added feature is estimated with maximum error of 0.6 units, feature size with maximum error of 0.4 units and coordinate values representing position with maximum error of 0.3 units. These results demonstrate the successful encoding of complex geometric information, beyond merely the shape of the 3D object, with potential application in the design of search engine functionality. (c) 2023 The Authors. Published by Elsevier B.V.
Pansharpening refers to the fusion of a multispectral image (MS) and a panchromatic image (PAN) to obtain a new image with the same spatial resolution as the PAN image and the same spectral resolution as the MS image....
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Pansharpening refers to the fusion of a multispectral image (MS) and a panchromatic image (PAN) to obtain a new image with the same spatial resolution as the PAN image and the same spectral resolution as the MS image. This paper describes a new, efficient, and accurate pansharpening architecture. The Vector-Quantized Variational autoencoder (VQ-VAE) is the foundation of the proposed method. The VQ-VAE model is trained to learn the non-linear mapping of degraded panchromatic image patches to high-resolution patches. This approach ensures that high-resolution patches can be recovered from low-resolution ones. After training on PAN patches, the VQ-VAE estimates high-resolution multispectral patches for each band of the original multispectral image before reconstructing the high-resolution multispectral image from the patches. The original multispectral image, the panchromatic image, and the estimated high-resolution multispectral image are combined through a modified Component Substitution (CS) process to obtain the pansharpened image. Three large satellite datasets from urban areas with 4-band spectral resolution (blue, green, red, and near-infrared) were used to evaluate the proposed pansharpening method's performance. The effectiveness of the proposed method is demonstrated by the quantitative and visual results obtained compared to several literature approaches.
The Internet of things(IoT)is an emerging paradigm that integrates devices and services to collect real-time data from surroundings and process the information at a very high speed to make a *** several advantages,the...
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The Internet of things(IoT)is an emerging paradigm that integrates devices and services to collect real-time data from surroundings and process the information at a very high speed to make a *** several advantages,the resource-constrained and heterogeneous nature of IoT networks makes them a favorite target for cybercriminals.A single successful attempt of network intrusion can compromise the complete IoT network which can lead to unauthorized access to the valuable information of consumers and *** overcome the security challenges of IoT networks,this article proposes a lightweight deep autoencoder(DAE)based cyberattack detection *** proposed approach learns the normal and anomalous data patterns to identify the various types of network *** most significant feature of the proposed technique is its lower complexity which is attained by reducing the number of *** optimally train the proposed DAE,a range of hyperparameters was determined through extensive experiments that ensure higher attack detection *** efficacy of the suggested framework is evaluated via two standard and open-source *** proposed DAE achieved the accuracies of 98.86%,and 98.26%for NSL-KDD,99.32%,and 98.79%for the UNSW-NB15 dataset in binary class and multi-class *** performance of the suggested attack detection framework is also compared with several state-of-the-art intrusion detection *** outcomes proved the promising performance of the proposed scheme for cyberattack detection in IoT networks.
Graph anomaly detection, aimed at identifying anomalous patterns that significantly differ from other nodes, has drawn widespread attention in recent years. Due to the complex topological structures and attribute info...
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ISBN:
(纸本)9789819755714;9789819755721
Graph anomaly detection, aimed at identifying anomalous patterns that significantly differ from other nodes, has drawn widespread attention in recent years. Due to the complex topological structures and attribute information inherent in graphs, conventional methods often struggle to effectively identify anomalies. Deep anomaly detection methods based on Graph Neural Networks (GNNs) have achieved significant success. However, they face the challenge of not only obtaining limited neighborhood information but over-smoothing. Over-smoothing is the phenomenon where the representations of nodes gradually become similar and flattened across multiple convolutional layers, thereby limiting the comprehensive learning of neighborhood information. Therefore, we propose a novel anomaly detection framework, TransGAD, to address these challenges. Inspired by the Graph Transformer, we introduce a Transformer-based autoencoder. Treating each node as a sequence and its neighborhood as tokens in the sequence, this autoencoder captures both local and global information. We incorporate cosine positional encoding and masking strategy to obtain more informative node representations and leverage reconstruction error for improved anomaly detection. Experimental results on seven datasets demonstrate that our approach outperforms the state-of-the-art methods.
Zero-shot learning aims to learn a visual classifier for a category which has no training samples leveraging its semantic information and its relationship to other categories. It is common, yet vital, in practical vis...
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Zero-shot learning aims to learn a visual classifier for a category which has no training samples leveraging its semantic information and its relationship to other categories. It is common, yet vital, in practical visual scenarios, and particularly prominent in the uncharted ocean field. Phytoplankton plays an important part in the marine ecological environment. It is common to encounter the zero-shot recognition problem during the in situ observation. Therefore, we propose a dual autoencoder model, which contains two similar encoder-decoder structures, to tackle the zero-shot recognition problem. The first one is used for the projection from the visual feature space to a latent space, then to the semantic space. Inversely, the second one projects from the semantic space to another latent space, then back to the visual feature space. This structure guarantees the projection from the visual feature space to the semantic space to be more effective, through the stable mutual mapping. Experimental results on four benchmarks demonstrate that the proposed dual autoencoder model achieves competitive performance compared with six recent state-of-the-art methods. Furthermore, we apply our algorithm to phytoplankton classification. We manually annotated phytoplankton attributes to develop a practical dataset for this real and special domain application, i.e., Zero-shot learning dataset for PHYtoplankton (ZeroPHY). Experiment results show that our method achieves the best performance on this real-world application.
As regional economy develops rapidly, the ecological environment exposes a series of problems, with the characteristics of ecological resistance surfaces being obviously differentiated. In the context of the increasin...
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As regional economy develops rapidly, the ecological environment exposes a series of problems, with the characteristics of ecological resistance surfaces being obviously differentiated. In the context of the increasing advance in computer science, this research introduced a deep learning algorithm, autoencoder, to analyze the ecological resistance surfaces over a 20-year period in 23 counties and districts in the Three Gorges Reservoir Area. The main results are as follows: (1) the overall resistance surfaces were at a low level, with high values concentrated in the core urban areas and along the Yangtze River. (2) The spatial distributions of the autoencoder results were smoother and more focused compared to the results of analytic hierarchy process. (3) The XGBoost detection results indicated land cover types as the highest contributing factor to the resistance. (4) Habitat quality analysis revealed a high degree of spatial heterogeneity, with the northeastern regions exhibiting more favorable conditions and the densely populated urban centers in the southwest displaying degraded quality. (5) The regionalization analysis outlined key conservation area, key restoration area and moderate development area, proposing a strategic framework of "One Axis, Two Zones and Four Protection Screens" for guiding the long-term ecological development in the research region.
In the satellite operation domain, the accurate pre-diction of the Remaining Useful Life (RUL) of satellite subsystems and components is fundamental for an effective management of the mission. The accuracy of the RUL ...
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In this paper, we analyze the capabilities of several multiscale convolutional autoencoder architectures for reduced-order modeling of two-dimensional unsteady turbulent flow over a cylinder and the collapse of the wa...
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In this paper, we analyze the capabilities of several multiscale convolutional autoencoder architectures for reduced-order modeling of two-dimensional unsteady turbulent flow over a cylinder and the collapse of the water column. The results demonstrate the significance of multiscale convolution design for precision. Multiscale convolution, on the other hand, leads to the creation of millions of training parameters that require a large amount of memory. This results in an increase in the computational cost of the system. As a solution to this problem, we propose using modified convolution to reduce the number of training parameters within the model. As far as accuracy and computational efficiency are concerned, separable convolution yields the most efficient results in terms of accuracy. Moreover, the encoder component of the architecture is responsible for encoding high-dimensional data into a latent space with a low dimension. The latent spaces are transferred to the recurrent neural-type network and decoder section for the temporal evolution of the latent spaces and reconstruction of the flow field. In addition, the results demonstrate that GRU has fewer parameters than LSTM while maintaining the same accuracy.
In this paper, a neural network model is presented to identify fraudulent visits to a website, which are significantly different from visits of human users. Such unusual visits are most often made by automated softwar...
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ISBN:
(纸本)9783031234798;9783031234804
In this paper, a neural network model is presented to identify fraudulent visits to a website, which are significantly different from visits of human users. Such unusual visits are most often made by automated software, i.e. bots. Bots are used to perform advertising scams or to do scraping, i.e., automatic scanning of website content frequently not in line with the intentions of website authors. The model proposed in this paper works on data extracted directly from a web browser when a user or a bot visits a website. This data is acquired by way of using JavaScript. When bots appear on the website, collected parameter values are significantly different from the values collected during usual visits made by human website users. However, just knowing what values these parameters have is simply not enough to identify bots as they are being constantly modified and new values that have not yet been accounted for appear. Thus, it is not possible to know all the data generated by bots. Therefore, this paper proposes a neural network with an autoencoder structure that makes it possible to detect deviations in parameter values that depart from the learned data from usual users. This enables detection of anomalies, i.e., data generated by bots. The effectiveness of the presented model is demonstrated on authentic data extracted from several online stores.
Image anomaly detection (AD) is widely researched on many occasions in computer vision tasks. High -dimensional data, such as image data, with noise and complex background is still challenging to detect anomalies unde...
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Image anomaly detection (AD) is widely researched on many occasions in computer vision tasks. High -dimensional data, such as image data, with noise and complex background is still challenging to detect anomalies under the situation that imbalanced or incomplete data are available. Some deep learning methods can be trained in an unsupervised way and map the original input into low-dimensional manifolds to predict larger differences in anomalies according to normal ones by dimension reduction. However, training a single low-dimension latent space is limited to present the low-dimensional features due to the fact that the noise and irreverent features are mapped into this space, resulting in that the manifolds are not discriminative for detecting anomalies. To address this problem, a new autoencoder framework is proposed in this study with two trainable mutually orthogonal complementary subspaces in the latent space, by latent subspace projection (LSP) mechanism, which is named as LSP-CAE. Specifically, latent subspace projection is used to train the latent image subspace (LIS) and the latent kernel subspace (LKS) in the latent space of the autoencoder-like model respectively, which can enhance learning power of different features from the input instance. The features of normal data are projected into the latent image subspace, while the latent kernel subspace is trained to extract the irrelevant information according to normal features by end-to-end training. To verify the generality and effectiveness of the proposed method, we replace the convolutional network with the fully-connected network contucted in the real-world medical datasets. The anomaly score based on projection norms in two subspace is used to evaluate the anomalies in the testing. Consequently, our proposed method can achieve the best performance according to four public datasets in comparison of the state-of-the-art methods.
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