2,783 results
Search Results
2. Hybrid wet paper coding mechanism for steganography employing n-indicator and fuzzy edge detector
- Author
-
Chang, Chin-Chen, Lee, Jung-San, and Le, T. Hoang Ngan
- Subjects
- *
CRYPTOGRAPHY , *FUZZY systems , *OBJECT-oriented programming , *CODING theory , *COMPUTER security , *INFORMATION retrieval , *EMBEDDINGS (Mathematics) - Abstract
Abstract: Data hiding technique can facilitate security and the safe transmission of important information in the digital domain, which generally requires a high embedding payload and good stego image quality. Recently, a steganographic framework known as wet paper coding has been utilized as an effective strategy in image hiding to achieve the requirements of high embedding payload, good quality and robust security. In this paper, besides employing this mechanism as a fundamental stage, we take advantage of two novel techniques, namely, an efficient n-indicator and a fuzzy edge detector. The first is to increase the robustness of the proposed system to guard against being detected or traced by the statistics methods while allowing the receiver without knowledge of secret data positions to retrieve the embedded information. The second is to improve the payload and enhance the quality of stego image. The experimental results show that our proposed scheme outperforms its ability to reduce the conflict among three steganography requirements. [Copyright &y& Elsevier]
- Published
- 2010
- Full Text
- View/download PDF
3. Fast joint estimation of direction of arrival and towed array shape based on marginal likelihood maximization.
- Author
-
Wang, Junxiong, Pan, Xiang, Li, Ao, Liu, Fenting, and Jiao, Jianbo
- Subjects
- *
DIRECTION of arrival estimation , *QUASI-Newton methods , *OCEAN currents , *SIGNAL processing , *SENSOR arrays - Abstract
This paper addresses the joint estimation problem of directions of arrival of sources and towed array shape. Ocean currents and the maneuvering of the towing platform often cause the towed array to bend rather than stay in a straight line, so the array shape must be estimated to avoid performance degradation due to array mismatch. Existing joint estimation methods suffer from high computational complexity or the need for external sensors installed on the array. Therefore, this paper proposes a fast joint estimation algorithm that solely utilizes received acoustic data. The joint estimation is transformed into a sparse reconstruction optimization problem within the Bayesian estimation framework. Firstly, by decomposing the marginal likelihood function, a closed-form solution for the signal variance in the spatial domain is obtained. Then, the towed array shape is introduced as a hyperparameter into the marginal likelihood function and optimized using the quasi-Newton method. In this way, we accomplish joint estimation and reduce computational complexity. Multi-source simulation results show that the proposed method achieves high resolution and fast computational speed. The robustness and efficiency of the proposed joint estimation method are demonstrated by experimental results in the South China Sea. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
4. On design of preprocessing and postprocessing in cascaded-resonator-based harmonic analyzers and filter banks.
- Author
-
Kušljević, Miodrag D.
- Subjects
- *
HARMONIC suppression filters , *FILTER banks , *IMPULSE response , *RESONATOR filters , *HARMONIC analyzers - Abstract
• The generalized approach for design of the harmonic analyzers and filter banks is given. • The primary part is the resonator filter structure with cascaded resonators. • Frequency responses of the harmonic filters are reshaped by preprocessing or postprocessing filters. • Filter coefficients of resulting IIR filters are designed through the linear optimization techniques. • Optimization of the frequency response of one harmonic ensures the same shapes for all harmonic filters. The cascaded-resonator (CR)-based filter structure provides high attenuation in the stopbands thanks to the serially coupled resonators, which is an advantage in many applications of harmonic analyses and/or filtering. In addition to that, it has good properties provided by its parallel structure. On the other side, there are applications which besides the high stopband attenuation need wider (or even flat-top) passbands, lower group delays, etc. These performances can be modified/improved by preprocessing and postprocessing through reshaping of the primary CR-based filter bank frequency responses. The numerical complexity is also an important aspect where infinite impulse response (IIR) filters provide implementation with a smaller number of numerical operations, but involving nonlinearity of the phase responses and stability control issue. Although most of these issues have been discussed in the previous papers dealing with the design of the CR-based harmonic filtering and/or filter banks, the aim of this paper is to highlight them all together. In addition, some improvements of the previously described design techniques are suggested too. [Display omitted] [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
5. Gait recognition using deep learning with handling defective data from multiple wearable sensors.
- Author
-
Qin, Lipeng, Guo, Ming, Zhou, Kun, Chen, Xiangyong, and Qiu, Jianlong
- Subjects
- *
CONVOLUTIONAL neural networks , *DEEP learning , *WEARABLE technology , *FEATURE extraction , *INFORMATION filtering , *HUMAN activity recognition - Abstract
Gait recognition based on multiple wearable sensors has received widespread attention in recent years. Collecting data from various types of multimodal sensors allows for a more comprehensive capture of gait information. This effectively enhances gait recognition performance. However, the increase in the number of sensors also leads to the possibility of generating defective data during the process of data collection and processing, particularly data redundancy and data anomaly. Traditional solutions often involve complex data analysis and selection, which may result in important information being filtered out and high computational demands. To address these issues, this paper proposes a new method that combines the powerful feature extraction capabilities of convolutional neural networks. To address the issue of data redundancy, the Channel Multiscale-aware (CMSA) Module is designed. It extracts information with different receptive fields from different channels of the same feature map to directly reduce similarities in information. To address the issue of data anomaly, the Feature Combination based on Local Channel Attention (FCLCA) Module is designed to select channel segments least affected by data anomaly from the feature map. Attention mechanisms are incorporated into both the CMSA and FCLCA modules to facilitate the model in adapting and learning more crucial features. Additionally, improvements are made to their pooling structures. After numerous experiments, it was demonstrated that our model achieved superior performance in gait recognition tasks. • A novel deep learning method is proposed to address the issue of defective data arising from the use of multiple sensors. • To address data redundancy and anomaly in defective data, CMSA and FCLCA modules are proposed respectively. • The CMSA and FCLCA modules use attention mechanisms with improved pooling structures to adaptively learn crucial gait features. • Extensive experiments demonstrate the superior performance of the proposed method in this paper. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
6. LONet: Local Optimization Network for 3D point cloud semantic segmentation.
- Author
-
Su, Shengbin, Lu, Jian, Chen, Xiaogai, Zhang, Kaibing, and Zhou, Jian
- Subjects
- *
POINT cloud , *K-nearest neighbor classification , *GEOMETRIC shapes , *FACILITATED communication , *ENCODING - Abstract
In the point cloud segmentation tasks, the existing local feature aggregation methods in the up-sampling and down-sampling stages still rely on Euclidean distance to constrain the local aggregation process. However, this approach is susceptible to the influence of abnormal points leading to inaccuracies in fitting the original geometric shape of the point cloud. Therefore, this paper proposes a local gradient aggregation module, which incorporates gradient information of neighboring points during the aggregation process. This enables the model to capture fine-grained geometric information and extract richer local features. Additionally, we introduce a symmetric sampling strategy to improve computational efficiency. The same original mapping indices were used for both up-sampling and down-sampling aggregation. Thus, a large number of additional k-nearest neighbor calculations are avoided. Furthermore, this paper introduces a position-aware encoding in the attention mechanism to address the positional cues for short-term and long-term contexts, facilitating positional-aware communication between points. Numerous comparative experiments prove the effectiveness of the method in this letter. It obtained 72.1% mIoU on ScannetV2, and 72.4% mIoU on S3DIS. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
7. DCNet: A lightweight retinal vessel segmentation network.
- Author
-
Shang, Zhenhong, Yu, Chunhui, Huang, Hua, and Li, Runxin
- Subjects
- *
RETINAL blood vessels , *FEATURE extraction , *DATA mining , *DATA integrity , *CONTEXTUAL learning , *DEEP learning - Abstract
Retinal vessel segmentation is a crucial focus within the realm of medical image analysis, playing a pivotal role in early disease diagnosis, notably retinopathy. Deep learning has exhibited remarkable segmentation capabilities for retinal blood vessels, leveraging the advantages of contextual feature learning. However, there are still some shortcomings in fine retinal vessel segmentation due to the loss of semantic information due to too many pooling operations or limited receptive fields due to fewer pooling operations. In response to the nuanced balance required for expanding the receptive field while preserving information integrity during multiple downsampling operations, this paper introduces DCNet (Dilated Convolution Net), a novel lightweight three-layer dilated-convolution-based network tailored for retinal blood vessel segmentation. This three-layer architecture autonomously extracts crucial segmentation features from various levels of the feature map. Each layer comprises a dilated convolution Positive Sequence Block (PSB) and a dilated convolution Reverse Sequence Block (RSB). The dilated convolution operation is strategically exploited for its capacity to extend the receptive field, facilitating effective feature information extraction. Simultaneously, to alleviate semantic information loss within the deep network's feature map, this paper proposes the Nonlinear Feature Extraction Module (NFEM) to supplement shallow network feature information. Furthermore, to comprehensively leverage information from various scale features, a Feature Fusion Module (FFM) is introduced for multiscale vascular feature extraction, ultimately enhancing segmentation accuracy. DCNet undergoes rigorous evaluation on four publicly accessible retinal vascular datasets – DRIVE, STARE, CHASE_DB1, and HRF. Experimental results unequivocally demonstrate that DCNet achieves superior segmentation performance with fewer model parameters compared to existing state-of-the-art methods. The code for DCNet can be accessed on the following website: https://github.com/ChunhuiYu1/DCNet. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
8. High-order dilated nested arrays with increased degrees of freedom and reduced mutual coupling.
- Author
-
Shaalan, Ahmed M.A. and Du, Jun
- Subjects
- *
BIRTHPARENTS , *DEGREES of freedom , *DNA , *DETECTORS - Abstract
In a companion paper [32] , a sparse array called the dilated nested array (DNA) was introduced, which owns the same number of uniform degrees of freedom (DOFs) as the nested array but has the first and third constituent sub-arrays dense, since their sensors are uniformly spaced out by the critical inter-sensor spacing (2 × λ / 2). Therefore, in this paper we introduce two further dilations to address this shortcoming. In the first dilation - referred to as the one-sided dilated nested array (OS-DNA), Q f possible high-order extensions starting from the 2nd-order extension (Q = 2) to the (Q f + 1) th-order extension are applied to the third parent sub-array, and in the second dilation - referred to as the two-sided dilated nested array (TS-DNA), an additional extension is applied to the first parent sub-array. While the high-order extensions of the OS-DNA as well as the TS-DNA strictly preserve the same number of uniform DOFs of the parent DNA, the first extension of the OS-DNA eliminates all the sensor pairs with separation 2 in the third parent sub-array, whereas the Q th-order extensions (for 2 < Q ≤ Q f + 1) increase the number of nonuniform DOFs as Q increases. The TS-DNA then eliminates all the sensor pairs with spacing 2 in the first sub-array of the (Q f + 1) th-order extension and concurrently maintains the higher number of nonuniform DOFs of this parent order. As such, the TS-DNA, named the super dilated nested array (SDNA) as well, still retains the number of uniform and nonuniform DOFs of the highest-order extension of the OS-DNA and at the same time enjoys the ideal critical weights of the co-prime array. Many theoretical properties are proved and extensive simulations are included to demonstrate the superior performance of these arrays. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
9. Design and performance validation of CWT-MCA based interference mitigation for automotive radars.
- Author
-
Liu, Shengheng, Zhang, Zheng, Fei, Tai, Gong, Zhihan, Kou, Lian, Shan, Danfeng, Li, Lei, and Huang, Yongming
- Subjects
- *
ROAD vehicle radar , *RADAR interference , *WAVELET transforms , *COMPUTATIONAL complexity , *COMPUTER simulation - Abstract
Interference mitigation has been a vital area of focus within the realm of automotive radar research, holding paramount importance for augmenting advanced driver-assistance capabilities, particularly in vehicle-dense scenarios. This paper presents a novel interference mitigation scheme based on continuous wavelet transform and morphological component analysis (CWT-MCA). This method, in essence, transforms the time-domain signal into the time-frequency domain, subsequently enabling the direct separation of target and interference components, thereby circumventing the necessity for interference detection and identification. Additionally, this paper introduces a series of MCA algorithms grounded in various transform domains, which are subsequently compared with the traditional linear prediction based approach. We show through comprehensive numerical simulations and real-data experiments that CWT-MCA algorithm exhibits markedly superior interference mitigation performance while offering lower computational complexity, which makes it well-suited for real-time implementation in automotive radar systems. • Continuous wavelet transform and morphological component analysis are applied to mitigate interference for automotive radars. • Fast algorithm is proposed to accelerate computation. • Numerical studies and real-data experiments are conducted to validate the algorithm performance. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
10. One-bit encoded reconfigurable intelligent surface-aided radar anti-suppression interference.
- Author
-
Zhang, Yujia, Zhou, Yu, Chen, Zhanye, Shang, Song, Zhang, Linrang, and Du, Lan
- Subjects
- *
RADAR interference , *INTERFERENCE suppression , *ORTHOGRAPHIC projection , *GENETIC algorithms , *RADAR , *BISTATIC radar , *MONOPULSE radar - Abstract
Reconfigurable intelligent surfaces (RISs) are characterized by low cost and strong survivability and can change the electromagnetic characteristics of signals. Based on these characteristics, this paper deploys an RIS near a monostatic radar. The radar can receive direct signals from the target (jammer) and reflected signals from the RIS, thereby achieving multiview monostatic radar anti-main lobe suppression interference. This paper first establishes an RIS-aided radar echo signal model and then systematically analyzes the ability of the RIS-aided radar to resist main lobe suppression interference. Subsequently, the phase shift vector of the 1-bit encoded RIS is obtained using a genetic algorithm to achieve beam control. The simulation results showed that introducing an RIS to assist monostatic radar can effectively improve the anti-main lobe suppression interference ability of monostatic radar at a relatively low cost. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
11. Automatic reconstruction of radar pulse repetition pattern based on model learning.
- Author
-
Luo, Zhenghao, Yuan, Shuo, Shang, Wenxiu, and Liu, Zhangmeng
- Subjects
- *
RADAR signal processing , *RADAR , *MACHINE learning , *TIME perspective - Abstract
Compared with the traditional pulse repetition interval (PRI) parameters, PRI pattern can describe the temporal characteristics of radar more completely, and the method based on PRI pattern is more suitable for tasks of deinterleaving and identification. Therefore, effective reconstruction of PRI pattern is an important task in radar signal processing. However, previous PRI pattern reconstruction methods either set too many subjective parameters or have high requirements for the number of pulses, making it not very practical for analyzing actual radar signals. In this paper, the temporal rule of pulse train is modeled from the perspective of radar timing state switching. Then the pulses of different timing states in the pulse train are clustered based on state merging algorithms in model learning. The transitions between different timing states are established based on the pulse sets obtained by clustering. Finally, the PRI pattern of radar is reconstructed after processing interferential pulses and missing pulses. Based on the above method, this paper further proposes a method to reconstruct PRI patterns of all radars in interleaved pulse trains. Simulation results verify the effectiveness of the proposed PRI pattern reconstruction method. • PRI pattern reconstruction framework based on model learning. • Pulse clustering algorithm based on state merging. • Radar emitter division method for interleaved pulse trains. • Better adaptability to the data noises, PRI pattern order and small pulse number. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
12. Low-complexity reconfigurable FIR lowpass equalizers for polynomial channel models.
- Author
-
Moryakova, Oksana, Wang, Yinan, and Johansson, Håkan
- Subjects
- *
FINITE impulse response filters , *FIR , *POLYNOMIALS , *TRANSFER functions , *COMPUTATIONAL complexity - Abstract
This paper introduces realizations of a reconfigurable finite-impulse-response (FIR) filter for simultaneous equalization and lowpass filtering. The main advantage of the proposed solutions is computational complexity reduction compared to existing solutions for a given performance, which leads to reduced hardware complexity. The proposed structures employ properties of both a variable bandwidth (VBW) filter and a variable equalizer (VE) with variable coefficients. The overall transfer function of the proposed reconfigurable lowpass equalizer (RLPE) is a weighted linear combination of fixed subfilters where the weights are directly determined by the bandwidth and one or several parameters of the channel needed to be equalized. The paper provides design procedures based on minimax optimization and introduces a fast design method for the filter with several variable parameters that can substantially decrease the design time. Filter order estimation expressions as well as complexity expressions are presented for all proposed realizations. Design examples include comparison of the RLPE structures and a common approach of using a regular FIR equalization filter requiring online redesign when the bandwidth or channel characteristics are changed. It is shown that the number of general multiplications can be reduced up to 91% using the proposed RLPE. • Three low-complexity realizations of variable FIR filters with simultaneously variable bandwidth and equalization. • No need for online design when the bandwidth or channel characteristics are modified. • Design procedure to obtain the overall filter with the lowest complexity. • Design procedure to obtain the overall filter with the lowest complexity for reduced design time. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
13. A lightweight feature activation guided multi-receptive field attention network for light compensation.
- Author
-
Zhao, Yongcan, Li, Wei, Li, Shilong, and Cui, Zhisheng
- Subjects
- *
DISCRETE wavelet transforms , *IMAGE intensifiers , *IMAGE processing , *IMAGE compression - Abstract
Image enhancement techniques are commonly used to improve problems such as lack of brightness, high noise, and low contrast in low-light images. Notably, deep learning-based approaches have recently achieved substantial advancements in this domain. However, learning-based methods often require many parameters and multi-layer network structures to achieve high-quality enhancement effects, which limits their application in real-time image processing. To solve this problem, a lightweight Feature Activation Guided Multi-Receptive Field Attention Network (FAMANet) is designed in this paper. The Wavelet Feature Activation Block (WFAB) introduced in the network utilizes the discrete wavelet transform and residual connection to achieve selective activation of image features, thus reducing the redundant information in the feature map and improving the computational efficiency. In addition, the Multi-Receptive Field Attention (MRFA) introduced in this paper addresses the issue of inadequate pixel information and feature map loss stemming from a single input image by concentrating on the image structure, spanning from intricate details to the overall composition. By better-utilizing image information and distinguishing between global and local features, MRFA can improve the speed and efficiency of real-time image processing. After sufficient experimental validation, FAMANet significantly outperforms state-of-the-art methods in low-light image enhancement and exposure correction tasks. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
14. NLNet: A narrow-channel lightweight network for finger multimodal recognition.
- Author
-
Guo, Zishuo, Ma, Hui, and Liu, Junbo
- Subjects
- *
HUMAN fingerprints , *FINGERS , *FEATURE extraction , *RECOGNITION (Psychology) - Abstract
Multimodal biometric recognition has attracted more and more attention in recent years because of its security and accuracy. Compared with the single use of fingerprint or finger vein feature recognition, the multi-modal feature recognition method based on fingerprint and finger vein significantly improves the recognition performance. However, most of the multi-modal feature recognition networks have the disadvantages of large number of parameters and high training cost. In this paper, a narrow-channel lightweight network NLNet for fingerprint and finger vein recognition is proposed. The network adopts asymmetric narrow channel structure for lightweight design, and combines shallow network to improve the discriminating nature of the extracted features, which significantly reduces the model parameters and computation. In addition, a lightweight feature extraction module for building feature extraction branches is designed for NLNet. This module takes dimensional transformation feature extraction as the backbone, and the joint extension module and attention mechanism obtain low-redundancy multi-scale feature information. In terms of feature fusion, a feature fusion method based on PatchPooling is proposed. This method combines the characteristics of modal images, and uses Spatial dimension local mapping to increase the utilization rate of low-dimensional features, which effectively improves the richness of classified features. In this paper, experiments were carried out on the SDUMLA-HMT, NUPT-FPV, FVC HKP and HDPR-310 multimodal finger datasets, and the recognition accuracy was high as 97.72 %, 99.10 %, 99.67 % and 99.74 %, respectively. In addition, the effectiveness of the model is verified by comparing with other advanced methods. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
15. Extended target trajectory Poisson multi-Bernoulli mixture filters with unknown detection probability.
- Author
-
Xue, Qiutiao, Liao, Guisheng, Zheng, Xiangfei, and Wu, Sunyong
- Subjects
- *
KALMAN filtering , *BETA distribution , *PROBABILITY theory , *FILTERS & filtration , *MIXTURES - Abstract
In most multi-extended target tracking scenarios, the target detection probability is usually unknown and time-varying, which leads to biased estimation of the state and cardinality of extended targets in online filtering. In addressing the challenge, this paper presents the unknown detection probability extended target trajectory Poisson multi-Bernoulli mixture (U-TPMBM) filter. Compared to the existing extended target Poisson multi-Bernoulli Mixture (PMBM) filter, the U-TPMBM is firstly based on sets of trajectories, which allows for direct output of target trajectory and can lead to improved trajectory estimation performance. Besides, the U-TPMBM filter integrates the unknown detection probability with the target trajectory state and thus obtains the augmented state space. By recursively estimating the augmented states via multi-target filtering approaches, it successfully realizes online and joint estimates of the unknown detection probability and the target trajectory. Finally, the U-TPMBM filter is implemented by the Beta-Gamma Gaussian Inverse Wishart (BGGIW) mixture method, especially the BGGIW-TPMBM filter. The Beta distribution is utilized to propagate densities of the unknown detection probability and the GGIW distribution to propagate densities of the target trajectory. Based on the BGGIW distribution, the trackers's recursive and closed solutions are derived in detail. The simulation experiments demonstrate that the BGGIW-TPMBM proposed in this paper can achieve robust tracking performance, even when dealing with unknown detection probabilities. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
16. Interval type-2 possibilistic picture C-means clustering incorporating local information for noisy image segmentation.
- Author
-
Wu, Chengmao and Liu, Tairong
- Subjects
- *
SOFT sets , *FUZZY algorithms , *COMPUTATIONAL intelligence , *ARTIFICIAL intelligence , *IMAGE segmentation , *FUZZY sets - Abstract
Picture fuzzy C-means clustering is a novel computational intelligence method that has some advantages over fuzzy clustering in pattern analysis and machine intelligence. However, picture fuzzy clustering is easily affected by noise and weighting exponent, which seriously limits its widespread application. To address this issue, this paper proposes a new robust possibilistic clustering method called "interval type-2 possibilistic picture C-means clustering with local information". This method combines interval type-2 fuzzy sets with possibilistic C-means clustering based on picture fuzzy sets, strengthening the noise resistance of picture fuzzy clustering. Firstly, this paper creatively extends an improved possibilistic clustering with double weighing exponents to picture fuzzy sets, solving the problem of consistency clustering in existing possibilistic picture clustering. Second, this paper originally introduces a new picture local information factor in possibilistic picture clustering and further enhances the anti-noise robustness of the method by using spatial possibilistic picture partition information. Finally, this paper skillfully extends this clustering method to interval type-2 fuzzy sets, which can handle more flexibly high-order uncertainties than type-1 clustering method. Experimental results indicate that this proposed method has better segmentation performance and stronger noise suppression ability compared with existing picture fuzzy clustering and interval type-2 fuzzy clustering. In summary, this work has made significant contributions to the development of picture fuzzy clustering theory and its applications. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
17. Industrial defect detection and location based on greedy membrane clustering algorithm.
- Author
-
Tang, Yaorui, Yang, Bo, Peng, Hong, and Luo, Xiaohui
- Subjects
- *
ALGORITHMS , *ARTIFICIAL membranes , *DISTRIBUTED computing , *GLOBAL optimization , *PARALLEL programming , *FEATURE extraction - Abstract
This paper introduces a related model of membrane calculation in the defect detection and positioning of industrial components. It has the characteristics of distributed and parallel computing, and can efficiently search for better solutions in a given feature space. Inspired by the membrane clustering algorithm, this paper proposes a greedy membrane clustering algorithm and names it GMCA. GMCA is applied after the extraction of local features of normal samples. It uses a greedy strategy to construct a sub-feature set that describes the local characteristics of normal samples. During training, GMCA can learn the membrane cluster center of normal image blocks and each sub-feature within the cluster. At test time, the anomaly map is obtained by calculating the distance from the test sample block to the corresponding cluster center and the maximum distance from the cluster center to the nearest neighbor in the training sample. This solves the limitation of traditional algorithms requiring dataset alignment. In the unsupervised dataset MvTec AD, samples can be divided into object categories and texture categories according to the background of images. The pixel-level anomaly location index (AUROC) of this method on object category data reaches 98.3%. The image-level anomaly detection index (AUROC) on texture category data reaches 99.1%. • We design a computational model of membrane clustering using the evolutionary mechanisms and communicative mechanisms of cells. • GMCA has the global optimization characteristics of high accuracy and fast convergence of the membrane clustering algorithm. • GMCA has the local optimization characteristics of the greedy strategy. • GMCA solves the limitation of traditional defect detection and positioning methods that require dataset alignment. • Numerous experiments show the proposed GMCA performs competitively in industrial defect detection and location prediction. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
18. Most Cited Paper Award
- Author
-
El-Khamy, Said, Hadhoud, Mohiy M., Dessouky, Moawd I., Salam, Bassiouny M., and Abd El-Samie, Fathi E.
- Published
- 2008
- Full Text
- View/download PDF
19. Analysis of quantization noise in FBMC transmitters.
- Author
-
Alrwashdeh, Monther and Kollár, Zsolt
- Subjects
- *
TRANSMITTERS (Communication) , *NOISE , *FILTER banks , *TELECOMMUNICATION systems , *FILTER paper , *RANDOM noise theory - Abstract
This paper investigates Filter Bank MultiCarrier (FBMC) modulation implemented with frequency spreading and polyphase network-based in terms of the introduced quantization noise. As FBMC is considered one of the future candidates for 5G/6G communication systems due to its advantageous spectral properties, the introduced quantization noise in the implementation is an essential design criterion. Analytical expressions for fixed- and floating-point Quantization Noise Power (QNP) in FBMC transmitter schemes are given. Based on the results, it can be stated that the total QNP depends on the number of carriers, overlapping symbols, and the resolution of the quantizer. The results are verified through simulations. Estimating the quantization noise in FBMC systems in the function of the selected bit resolution and keeping it at an acceptable level is an essential design step. The results can be directly employed in the preliminary hardware design of FBMC transmitters, where the choice of the arithmetical units and the bit resolution is a key factor. • Different FBMC transmitter architectures are compared in terms of quantization noise. • Analytical formulas for the QNP at the output of FBMC transmitters are derived. • The effect of the Quantization noise on the PSD of the FBMC signal is analyzed. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
20. A novel aspect of automatic vlog content creation using generative modeling approaches.
- Author
-
Kumar, Lalit and Singh, Dushyant Kumar
- Subjects
- *
USER-generated content , *VIDEO blogs , *COMPUTER vision , *TEXT recognition - Abstract
Generative models have emerged as potential tools for creating high-quality images, videos, and text. This paper explores the application of generative models in automating vlog content creation. It addresses both static and dynamic visual elements, eliminating the need for human intervention. Traditional vlogs often require specific environmental conditions and proper lighting for the vlog creation. To streamline this process, an automated system utilizing the generative models is proposed here. Generative models excel at generating realistic content that seamlessly integrates with real-world content. They enhance overall video quality and introduce creative elements by generating new scenes and backgrounds. This paper categorizes various generative modeling techniques based on frame elements and foreground-background conditions. It offers a comparative analysis of different generative model variants tailored for specific objectives. Furthermore, the paper reviews existing research on generative models for video and image content generation, visual quality enhancement, diversity, and coherence outcomes. Additionally, the paper highlights practical uses of the generative model for content creation in various contexts, such as face swapping, scene translation, and virtual content insertion. The paper also examines the public datasets used to train generative models. These datasets contain diverse visual content such as celebrity images, urban landscapes, and everyday scenes. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
21. Optimal synchronization with binary marker for segmented burst deletion errors.
- Author
-
Yi, Chen, Zhou, Jihua, Zhao, Tao, Ma, Baoze, Li, Yong, and Lau, Francis C.M.
- Subjects
- *
BIT error rate , *TIME complexity , *SYNCHRONIZATION , *COMPUTATIONAL complexity , *ELECTRONIC records - Abstract
In some telecommunication and magnetic/digital recording applications, bits/symbols tend to be lost in the transmission due to the interference. In this paper, we consider a segmented burst deletion channel where in a block of L consecutive bits at most a single burst deletion of length up to D bits exists. Existing synchronization approaches either provide a poor synchronization performance or suffer from a high computational complexity. For example, the reduced state Forward Backward Algorithm (FBA) incurs high time and space complexities, i.e., O (n 3 2 ) and O (n) , respectively, where n denotes the sequence length. In this paper, we discover binary marker patterns which require the minimum D + 1 bits redundancy to detect the burst deletion with the length up to D bits for the segmented burst deletion channel, and propose an optimal algorithm to resynchronize the corrupted bit sequence that minimizes the expected bit error rate. As compared to the reduced state FBA, the time and space complexities of our proposed algorithm are reduced to O (n) and O (1) , respectively. Theoretical analysis and simulations verify the optimality of our proposed algorithm, and demonstrate that the expected bit error rate introduced in our proposed scheme is lower than that in the existing synchronization error detection schemes and that in the FBA under segmented burst deletion channels. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
22. Information criteria for structured parameter selection in high-dimensional tree and graph models.
- Author
-
Jansen, Maarten
- Subjects
- *
TREE graphs , *AKAIKE information criterion , *MALVACEAE , *FALSE positive error , *ELECTRONIC data processing , *DATA modeling - Abstract
Parameter selection in high-dimensional models is typically fine-tuned in a way that keeps the (relative) number of false positives under control. This is because otherwise the few true positives may be dominated by the many possible false positives. This happens, for instance, when the selection follows from a naive optimisation of an information criterion, such as AIC or Mallows's C p. It can be argued that the overestimation of the model comes from the optimisation process itself changing the statistics of the selected variables, in a way that the information criterion no longer reflects the true divergence between the selected model and the data generating process. Using lasso, the overestimation can also be linked to the shrinkage estimator, which makes the selection too tolerant of false positive selections. For these reasons, this paper works on refined information criteria, carefully balancing false positives and false negatives, for use with estimators without shrinkage. In particular, the paper develops corrected Mallows's C p criteria for structured selection in trees and graphical models. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
23. Sub-Nyquist sensing of Gaussian pulse streams with unknown shape factor based on information fitting.
- Author
-
Yun, Shuangxing, Fu, Ning, and Qiao, Liyan
- Subjects
- *
RANDOM noise theory , *PARAMETER estimation , *WHITE noise , *PRIOR learning , *SENSES , *PHOTOPLETHYSMOGRAPHY - Abstract
Gaussian pulse streams can be characterized by a finite number of unit-time parameters, and classical Finite Rate of Innovation (FRI) sampling enables sub-Nyquist sensing of these signals. However, prior knowledge of its shape factor is required, limiting FRI's applicability. This paper proposes a solution to the FRI sampling problem of Gaussian pulse streams with an unknown pulse shape factor. We aim to fit pulse shape information from sub-Nyquist samples and reconstruct parameters using spectral estimation methods. We first demonstrate the feasibility of fitting the shape factor from sub-Nyquist samples and provide the fitting algorithm and related fitting errors in detail. This paper also provides the Cramer-Rao lower bound (CRLB) on parameter estimation accuracy of Gaussian pulse streams under analog white Gaussian noise, offering a statistical perspective of our proposed information fitting method's performance. We qualitatively demonstrate that the information-fitting method can also be applied to a wider range of FRI pulse stream forms. Simulation experiments show that our proposed information fitting method achieves high accuracy in parameter estimation of the signal when the pulse shape factor is unknown. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
24. On the (non-) reliance on algorithms—A decision-theoretic account.
- Author
-
Sinclair-Desgagné, Bernard
- Subjects
- *
AMBIGUITY , *RECOMMENDER systems , *CONTROL (Psychology) , *DECISION making , *ALGORITHMS , *INFORMATION resources management , *AVERSION - Abstract
A wealth of empirical evidence shows that people display opposite behaviors when deciding whether to rely on an algorithm, even if it is inexpensive to do so and using the algorithm should enhance their own performance. This paper develops a formal theory to explain some of these conflicting facts and submit new testable predictions. Drawing from decision analysis, I invoke two key notions: the 'value of information' and the 'value of control'. The value of information matters to users of algorithms like recommender systems and prediction machines, which essentially provide information. I find that ambiguity aversion or a subjective cost of employing an algorithm will tend to decrease the value of algorithmic information, while repeated exposure to an algorithm might not always increase this value. The value of control matters to users who may delegate decision making to an algorithm. I model how, under partial delegation, imperfect understanding of what the algorithm actually does (so the algorithm is in fact a black box) can cause algorithm aversion. Some possible remedies are formulated and discussed. • This paper initiates a formal decision-theoretic approach to make sense of the empirical evidence concerning people's attitudes towards algorithms. • This approach exploits two fundamental notions: the value of information and the value of control. • Ambiguity aversion will tend to decrease the value of algorithmic information; repeated exposure to algorithms may not increase it. • A first model of 'black box' algorithms is developed to analyze the value of keeping versus delegating control. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
25. A mutual information-maximizing quantizer based on the noise-injected threshold array.
- Author
-
Zhai, Qiqing and Wang, Youguo
- Subjects
- *
STOCHASTIC resonance , *RANDOM noise theory , *DYNAMIC programming , *CHANNEL coding , *NOISE , *FEATURE selection , *BINARY codes - Abstract
Channel quantization, particularly designing optimal quantizers maximizing the mutual information between channel input and quantizer output, plays a great role in communications. This paper focuses on the mutual information-maximizing quantizer and explores stochastic resonance (SR) effect on quantization performance when the channel is constructed by a noise-injected threshold array. First, we present the structure of an optimal quantizer. Such a quantizer is determined by using optimal boundaries to partition the set of channel output into disjoint subsets consisting of consecutive integers. Next, the optimal binary quantizer is examined and the optimal noise in the array is derived. For non-optimal Gaussian noise, we find that noise helps to improve mutual information when the threshold is greater than the amplitude of input signal. This means SR occurs in subthreshold case. Moreover, optimal non-binary quantizers are obtained based on dynamic programming. In this case, the Gaussian noise's effect on enhancing mutual information is also demonstrated. At the same time, the impact of the number of threshold units or the quantization levels is explored. Finally, a non-Gaussian noise, i.e., Cauchy noise, is considered, and its SR effect is displayed as well. These results in this paper may be useful for channel coding. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
26. Sequential centralized fusion of multiple passive acoustic sensors with unknown propagation delays.
- Author
-
Hao, Huijuan and Duan, Zhansheng
- Subjects
- *
ACOUSTIC emission , *ACOUSTIC transducers , *MULTIPLE target tracking , *DETECTORS , *ACOUSTIC measurements , *TRACKING radar , *COMPUTATIONAL complexity - Abstract
In this paper, we address the problem of target tracking using multiple acoustic sensors to observe the target state with unknown propagation delays. This problem occurs because the measurements received by multiple acoustic sensors located at different positions are from different unknown emission times of the acoustic signal even if the sensors receive measurements simultaneously; thus, they cannot be stacked up directly for centralized fusion as usual. However, the target states at different unknown emission times can be aligned to a common measurement received time by the retrodiction of state prediction. On this basis, herein we propose the centralized fusion of multiple acoustic sensors via sequential processing, namely, sequential centralized fusion (SCF). First, the measurement received time is chosen as the target state time, and the target state is predicted to this time for tracking. Second, state prediction is retrodicted to the signal emission times by solving augmented implicit nonlinear equations through Wegstein's method. Third, the state prediction is updated with acoustic measurements sequentially at measurement received time. Compared with the existing distributed fusion methods, our proposed SCF method has smaller computational complexity and better tracking performance. Illustrative examples demonstrate that SCF outperforms covariance intersection and the largest ellipsoid approximation. • Multiple acoustic sensors with unknown delays for target tracking are considered. • A sequential centralized fusion method is proposed in this paper. • Choosing measurement received time as target state time reduces extra prediction step. • The Wegstein's method avoiding to calculate Jacobians is used. • Sequential update decreases computational complexity, and improves tracking accuracy. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
27. Secure spectrum sharing and power allocation by multi agent reinforcement learning.
- Author
-
Kazemi, Neda and Azghani, Masoumeh
- Subjects
- *
POWER spectra , *REINFORCEMENT learning , *INFORMATION networks , *REINFORCEMENT (Psychology) , *DECISION making - Abstract
In this paper, the problem of secure spectrum sharing and power allocation for the vehicle to vehicle communication has been investigated. The information transmitted in the network might be overheard by the eavesdropper. The aim of this paper is to share the vehicle to infra structure frequency bands with the vehicle to vehicle links in order to maximize the sum rate of the network as well as minimizing the data received by the eavesdropper. To achieve this goal, we have suggested to leverage some friendly jammers to prevent the leakage of information to the eavesdropper. A multi-agent reinforcement learning based approach has been developed to smartly determine the power level, frequency band, and jammer number in a way that the secure rate is maximized. All the agents would cooperate in making the decision in every state which might change over time. The simulation results confirm the superiority of the suggested scheme over its counterparts in various scenarios. The security provided by the proposed method is much higher than those of the other schemes. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
28. A review of the application of staircase scene recognition system in assisted motion.
- Author
-
Kong, Weifeng, Tan, Zhiying, Fan, Wenbo, Tao, Xu, Wang, Meiling, Xu, Linsen, and Xu, Xiaobin
- Subjects
- *
STAIRCASES , *MULTISENSOR data fusion , *FOOT , *ROBOTIC exoskeletons , *MOBILE robots , *WEARABLE technology - Abstract
Staircase recognition is of great significance for exoskeleton robot mode switching and mobile robot foothold calculation, which can improve the overall performance of the robot in the staircase scene. As a common terrain, stairs are quite difficult for mobile robots or people with lower limb disabilities and visual impairment. However, there are still some problems from the sensor's characteristics and external interference limiting the development of this technology. Despite the growing demand for recognition in this area and the emergence of a large number of related methods, there is a lack of a systematic and comprehensive review. Therefore, this paper reviews and compares the advantages and disadvantages of various methods, and provides the next research hotspots and directions. This paper first analyzes and summarizes the current mainstream perception hardware from the perspective of scene information acquisition, including wearable sensors, photoelectric sensors, multi-sensor fusion and ultrasonic sensors, which can be installed on the head, chest, waist, knees and legs, and soles of feet, respectively. Then, the existing recognition methods of ascending and descending stairs are compared and analyzed from four aspects of sensor type, installation location, processing algorithm and recognition accuracy. The research progress of staircase scene recognition in auxiliary motion is introduced in detail. Finally, the application prospects and fields of staircase scene recognition are analyzed, and the future development direction is prospected. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
29. Traffic prediction for 5G: A deep learning approach based on lightweight hybrid attention networks.
- Author
-
Su, Jian, Cai, Huimin, Sheng, Zhengguo, Liu, A.X., and Baz, Abdullah
- Subjects
- *
DEEP learning , *COMPUTER network traffic , *5G networks , *TELECOMMUNICATION systems , *FEATURE extraction , *LEARNING ability - Abstract
The maturity of 5G technology provides a guarantee for increasingly large communication networks, while the resources required for communication and computation are also increasing, and reasonable resource allocation can improve the efficiency of network communication and reduce the consumption of communication resources. Existing deep learning methods have been able to predict network traffic to a certain extent, so as to solve the communication efficiency and resource consumption problems in the field of integrated sensing, communication and computation (ISCC) through rational resource allocation. However, the following problems still exist: (1) The feature learning ability of the prediction model is insufficient, and the prediction accuracy needs to be improved. (2) Powerful and complex deep learning methods lead to an increase in the prediction cost of the model. To address these problems, this paper proposes a deep learning method based on a lightweight hybrid attention network. In order to capture the key features of 5G data more effectively, an efficient hybrid attention mechanism (EHA) is proposed. After this attention is applied to convolution, the key information can be well enhanced. We use depthwise separable convolution in feature extraction, which greatly improves the efficiency of lightweight convolution layer (LC) in feature extraction. Combined with the efficient hybrid attention mechanism (EHA), the proposed model has better lightweight properties. Experimental results show that the model proposed in this paper has lower RMSE and MAE values on the three datasets, as well as fewer parameters and computational effort compared to the baseline scheme. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
30. Most Cited Paper Award
- Published
- 2007
- Full Text
- View/download PDF
31. Announcement: Outstanding Paper Award for 2003-2005
- Published
- 2006
- Full Text
- View/download PDF
32. Announcement: Outstanding Paper Award for 2002-2004
- Published
- 2006
- Full Text
- View/download PDF
33. Announcement: Outstanding Paper Award for 2001-2003
- Published
- 2005
- Full Text
- View/download PDF
34. Outstanding Paper Award for 2001-2003
- Published
- 2004
- Full Text
- View/download PDF
35. Outstanding paper awards for 1999-2002
- Published
- 2003
- Full Text
- View/download PDF
36. Call for Papers: 33rd European Conference on Mathematical Psychology (EMPG2002)
- Published
- 2002
- Full Text
- View/download PDF
37. Bistatic MIMO radar height estimation method based on adaptive beam-space RML data fusion.
- Author
-
Tang, Derui, Zhao, Yongbo, Niu, Ben, and Zhang, Mei
- Subjects
- *
BISTATIC radar , *MIMO radar , *MULTISENSOR data fusion , *MEAN square algorithms - Abstract
This paper focuses on the beam-space target height estimation for bistatic multiple-input multiple-output (MIMO) radars, which is greatly affected by the multipath effect in low-elevation areas. The beam-space technique compresses the data and reduces computation, making it an ideal solution for this problem. However, there is a lack of research on beam-space target height estimation for bistatic MIMO radar, which this paper aims to address. In order to obtain the target height parameters accurately, we propose bistatic MIMO radar height estimation method based on adaptive beam-space refined maximum likelihood (RML) data fusion. First, we analyze and simplify the signal model, and obtain rough estimation of direction of departure (DOD) and direction of arrival (DOA) using digital beamforming (DBF) scanning technique; then, we convert target signals from the element space to the beam-space, separates the transmitter and the receiver signals, and obtain two target height estimations using the beam-space RML algorithm; finally, the minimum mean square error (MSE) criterion is used to fuse the two height estimations of the transmitter and the receiver. On this basis, we also analyze the application and advantages of RML algorithm in complex terrain through the measured data. In addition, the computational complexity of the proposed algorithm and the comparison algorithm is also given. Through some simulation results, it is not difficult to find that the proposed algorithm has good estimation accuracy and robustness. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
38. Integrated sensing, lighting and communication based on visible light communication: A review.
- Author
-
Liang, Chenxin, Li, Jiarong, Liu, Sicong, Yang, Fang, Dong, Yuhan, Song, Jian, Zhang, Xiao-Ping, and Ding, Wenbo
- Subjects
- *
OPTICAL communications , *VISIBLE spectra , *TELECOMMUNICATION , *WIRELESS communications , *DAYLIGHT , *SYSTEMS design - Abstract
As wireless communication rapidly evolves and the demand for intelligent connectivity grows, the need for precise sensing integrated with efficient communication becomes paramount. While traditional Integrated Sensing and Communication (ISAC) methods have laid foundational groundwork, they grapple with environmental limitations and significant propagation losses. Visible Light Communication (VLC) emerges as a transformative solution characterized by its high-speed transmission, minimal latency, cost-efficiency, and seamless installation. This paper introduces the Lighting, Sensing, and Communication (LiSAC) concept for VLC and systematically reviews the technical aspects, such as channel characteristics, modulation techniques, and system design. Specifically, this paper presents the evolution of the LiSAC system, its integration with other communication technologies, its applications in various fields, and its challenges. At the end of this paper, we outlooked LiSAC in the future, in which high-quality communication will integrate pinpoint sensing accuracy. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
39. Decentralized classification in sensor networks via sparse representation and constrained fractional programming.
- Author
-
Ye, Zhonghua, Zhu, Hong, and Fang, Xueyi
- Subjects
- *
SENSOR networks , *DATA privacy , *CLASSIFICATION algorithms , *FRACTIONAL programming , *DISTRIBUTED algorithms , *ELECTRONIC data processing - Abstract
This paper investigates the problem of decentralized classification algorithm in sensor networks, i.e., the data is captured by privacy sensor or the data is not suitable for publication. Therefore, we may maintain the privacy of the data captured and processed by each sensor. The number of the sensors can be selected based on actual application situations. In addition, even if some sensors break down, the classification process still works and thus the proposed scheme is robust against the traditional center scheme. The contributions of this paper are: i) two new classification algorithms are proposed based on the sparse representation and constrained fractional programming. One is for the centralized environment while the other is for the decentralized environment, where the decentralized network node is able to process its own data to extract useful information by implementing some local computation, communication, and storage operations; ii) to reduce the redundant features and noisy data of the original data is helpful to improve the speed of algorithm, we form a new classification strategy by combining the sparsity transform with the classifier; iii) to improve the robustness of the classifiers in abnormal and dangerous situations, we construct a constrained fractional programming to enforce the discriminant ability of the classifier so that the transformed coefficient vector should be closer to the class center of itself but being far away from centers of other class; iv) to handle the proposed centralized/decentralized classification problems, we decouple the constrained fraction via the Dinkelbach algorithm and alternating minimization. Finally, numerical examples are provided to verify the proposed algorithms realized in a distributed manner have the same recognition rate with the centralized algorithm. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
40. Multi-sensor fusion rolling bearing intelligent fault diagnosis based on VMD and ultra-lightweight GoogLeNet in industrial environments.
- Author
-
Wang, Shouqi and Feng, Zhigang
- Subjects
- *
MULTISENSOR data fusion , *FAULT diagnosis , *ROLLER bearings , *DEEP learning , *ARTIFICIAL intelligence , *GRAYSCALE model , *FEATURE extraction - Abstract
• The paper presents a lightweight model with satisfactory performance in complex industrial noise environments. • Data fusion using data from multiple sensors for more complete fault information. • Design a unique grayscale feature map based on IMF components to obtain multi-sensor and multi-frequency band fault features. • Design a UL-GoogLeNet lightweight fault diagnosis model based on GoogLeNet and ULSAM. As artificial intelligence and sensor technology develop rapidly, intelligent fault diagnosis methods based on deep learning are widely used in industrial production. However, in practical industrial applications, the complex noise environment affects the performance of the diagnostic model, and the huge model parameters cannot meet the requirements of low cost and high performance in industrial production. To address the above problems, this paper proposes a lightweight intelligent fault diagnosis model using multi-sensor data fusion that not only meets the lightweight requirements of "small, light, and fast", but also realizes high accuracy diagnosis in noisy environments. Firstly, the vibration signals from different sensors of rolling bearings are processed using the variational mode decomposition (VMD) to design a unique method of constructing grayscale feature maps based on each intrinsic modal function (IMF) component. Then, the ultra-lightweight GoogLeNet model (UL-GoogLeNet) is constructed to adjust the traditional GoogLeNet structure, while the Ultra-lightweight subspace attention module (ULSAM) is introduced to reduce the model parameters and enhance the feature extraction capability. UL-GoogLeNet is trained and tested by dividing the grayscale feature maps into training and testing sets to realize the intelligent recognition of different fault types in rolling bearings. Experiments are conducted on two datasets and compared with multiple methods, and the final experimental results prove the effectiveness and superiority of the proposed method in this paper. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
41. Analysis of the channel estimate model in passive radar using OFDM waveforms.
- Author
-
Lyu, Xiaoyong, Liu, Baojin, Fan, Wenbing, and Quan, Zhi
- Subjects
- *
PASSIVE radar , *ORTHOGONAL frequency division multiplexing , *SIGNAL-to-noise ratio - Abstract
The paper takes an in-depth analysis of the channel estimate model (CEM) in passive radar using the orthogonal frequency division multiplexing (OFDM) waveforms. The CEM has been intensively exploited in OFDM passive radar, where the channel estimates (CE) are obtained from the original digitized received signal (ODRS), and target detection is performed based on CEs. However, traditional CEM is derived neglecting the inter-carriers interference (ICI). The influence of the ICI on target detection has rarely been discussed previously. In fact, target with large power and Doppler frequency can induce strong ICI, which increases the noise floor, and thus imposes significant influence on the detection of the other targets, especially the weak targets. In this paper, we rederive the CEM taking the ICI into consideration, and obtain a new CEM. In the new CEM, a specific target has two components, i.e., the useful signal part, and ICI. We derive the useful signal to noise ratio (SNR) and ICI to noise ratio (ICINR) theoretically, and provide compact expressions. We reveal the relationship between the SNR and ICINR in the CE, and the SNR in the ODRS. Based on the theoretical derivation, the influence of ICI is analysed. We also discuss the elimination of the ICI. The influence of ICI can be eliminated by cancelling the target signal that induces the ICI from the CEM. A target signal cancellation method is developed based on the new CEM. Simulations demonstrate the effectiveness of the theoretical analysis of the CEM and the proposed cancellation method. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
42. How averaging individual curves transforms their shape: Mathematical analyses with application to learning and forgetting curves.
- Author
-
Murre, Jaap M.J.
- Subjects
- *
MATHEMATICAL analysis , *DISTRIBUTION (Probability theory) , *LOGARITHMIC functions , *EXPONENTIAL functions , *CURVES - Abstract
This paper demonstrates how averaging over individual learning and forgetting curves gives rise to transformed averaged curves. In an earlier paper (Murre and Chessa, 2011), we already showed that averaging over exponential functions tends to give a power function. The present paper expands on the analyses with exponential functions. Also, it is shown that averaging over power functions tends to give a log power function. Moreover, a general proof is given how averaging over logarithmic functions retains that shape in a specific manner. The analyses assume that the learning rate has a specific statistical distribution, such as a beta, gamma, uniform, or half-normal distribution. Shifting these distributions to the right, so that there are no low learning rates (censoring), is analyzed as well and some general results are given. Finally, geometric averaging is analyzed, and its limits are discussed in remedying averaging artefacts. • Averaging over individual learning (or forgetting, etc.) curves changes their shape, where exponential functions may change into power functions and power functions into log power functions. • Averaging over logarithmic functions retains the shape. • For exponential and power functions, geometric averaging retains the shape. • Geometric averaging over logarithmic functions does not retain that shape. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
43. Performance analysis of massive MIMO offshore system with distributed antenna subarrays.
- Author
-
Sun, Yu, Yue, Dian-Wu, Zhang, Yan, Jin, Si-Nian, and Li, Guang-Hui
- Subjects
- *
SYMBOL error rate , *MONTE Carlo method , *PROBABILITY density function , *OCEAN waves , *ANTENNAS (Electronics) , *WIRELESS channels - Abstract
In this paper, we propose a transmission scheme of analog precoding for an offshore communication system with distributed antenna subarrays to serve multiple vessels. The proposed analog precoding scheme relies only on line-of-sight (LOS) components of the fading channels, since the accurate estimation of small-scale fading information is challenging due to the varying sea state of maritime wireless channels, such as reflection, scattering, and ducting effect. We derive an approximate expression for the ergodic achievable rate, and emphasize the multiplexing gain analysis of the whole system with a large antenna configuration. In addition, we derive the probability density function (PDF) of signal-to-interference-and-noise ratio (SINR) and further obtain closed-form expressions of symbol error rate (SER). Monte Carlo simulations verify the theoretical analysis, and numerical results demonstrate that the performance of the proposed LOS-based analog precoding scheme for the distributed multiple-input multiple-output (MIMO) offshore system is extremely near to the limitation of system performance, i.e., the ideal situation without any interference. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
44. CSPGNet: Cross-scale spatial perception guided network for tiny object detection in remote sensing images.
- Author
-
Chen, Penglei, Wang, Jiangtao, Zhang, Zhiwei, and He, Cheng
- Subjects
- *
OBJECT recognition (Computer vision) , *MINIATURE objects , *SPACE perception , *REMOTE sensing , *SPINE - Abstract
Tiny object detection in remote sensing images has been a popular and challenging task in recent years. Due to the mismatch of feature scales that tiny objects rely on and the interference from complex surroundings in remote sensing images, traditional object detection algorithms still exhibit poor performance in detecting tiny objects. Based on the above observations, this paper proposes a cross-scale spatial perception guided network (CSPGNet) for tiny object detection in remote sensing images. Specifically, we first designed a cross-scale hierarchical perception module (CSHPM) at the topmost level of the Faster R-CNN backbone network to integrate contextual information from various levels and scales, thereby optimizing the representation of tiny objects in feature scales. Furthermore, to address the issue of information loss that occurs when combining low-resolution feature layers with those generated by the aforementioned module during the fusion process, we have developed an adaptive spatial alignment unit (ASAU) that utilizes variability convolution to adaptively align the spatial information of neighboring feature layers. Finally, we present an attention-guided information integration module (AGIIM), which utilizes large kernel attention to guide the feature information, improving tiny objects' global and local information across various feature layers and mitigating the influence of complex environments on the detection task. Extensive experiments were conducted on two publicly available tiny object datasets, namely AI-TOD and VisDrone2019, and the results demonstrate that our approach achieves higher accuracy compared to the majority of state-of-the-art methods. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
45. Bias-compensated based diffusion affine projection like maximum correntropy algorithm.
- Author
-
Li, Chengjin, Zhao, Haiquan, and Xiang, Wang
- Subjects
- *
BURST noise , *PARAMETER estimation , *PROBLEM solving , *ALGORITHMS , *NOISE - Abstract
A distributed network with highly colored input signal is often located in a scenario where the output signal is subject to impulse noise. Under the above scenario, the performance of the diffusion adaptive algorithms will suffer from performance degradation, which includes distributed parameter estimation accuracy and convergence/tracking rate. To solve these problems, the diffusion affine projection like maximum correntropy (DAPLMC) algorithm is proposed. Moreover, highly colored input signals tend to be mixed with noise, which will lead to biased estimation. To deal with the adverse impact of biased estimation, based on the bias compensation (BC) strategy, the bias-compensated DAPLMC (BC-DAPLMC) algorithm is proposed in this paper. By analyzing the convergence performance of the BC-DAPLMC algorithm, a range of its step size is obtained, and the steady-state error of the BC-DAPLMC algorithm is studied. The superior performance of the BC-DAPLMC algorithm and theoretical steady-state error analysis is validated by simulation results. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
46. Transmit beampattern design for FDA-MIMO radar using complex manifold optimization.
- Author
-
Özen, Berkcan and Tuncer, Temel Engin
- Subjects
- *
COMPLEX manifolds , *ANTENNAS (Electronics) , *MIMO radar , *PROBLEM solving , *RADAR , *TRANSMITTERS (Communication) - Abstract
Frequency diverse array multiple-input multiple-output (FDA-MIMO) radar can produce time-stationary range-angle dependent beampattern. The problem with these beampatterns is the repeating lobes in the angle-range domain. Different methods are proposed to obtain better beampattern in terms of grating lobe and sidelobe suppression by using frequency offsets. However, these methods mostly choose the frequency offsets using an analytic expression and do not offer a control on the resulting range beampattern. In this paper, a new method for transmit beampattern design in range is presented. This method transfers the design problem into a tangential space and solves the problem using complex manifolds through an optimization procedure. The proposed approach considers amplitude tapering in the transmitter antenna elements and the practical instrumented range of the radar. Range beampattern constraints can be defined conveniently leading to an effective design process. Several simulations are done to show that the proposed method can significantly improve the beamwidth and sidelobe level in range patterns. • Transmit beampattern design by finding frequency offsets optimized for range folded clutter and minimum sidelobe level. • Convenient range beampattern constraints defined in terms of pass, stop and transition band. • Practical beampattern design without using data aided computationally expensive methods. • Flexibility in terms of amplitude tapering in the transmitters. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
47. Exploring bounded component analysis using an ℓ∞ norm criterion.
- Author
-
Brotto, Renan D.B., Nose-Filho, Kenji, and Romano, João M.T.
- Subjects
- *
BLIND source separation , *COMPUTER simulation - Abstract
In this paper we propose a new criterion for the Blind Source Separation (BSS) of antisparse bounded sources, based on the sum of the ℓ ∞ -norm of the sources. Based on the observation that the mixing process of bounded sources with any mixing matrix with unitary Frobenius norm will increase the ℓ ∞ -norm of the sources, unless it is the identity matrix, the minimization of the sum of the ℓ ∞ -norm of the sources can be used for the estimation of a separation matrix. To that, a Principle Component Analysis technique followed by a Givens Rotations based optimization method can be used for the separation of independent bounded sources. Also, the Givens Rotations based optimization method can be used for the separation of correlated bounded sources mixed by a rotation matrix. We theoretically analyze the proposed criterion and assess its performance through numerical simulations involving three distinct types of bounded signals. Our theoretical and experimental findings underscore the efficacy of the ℓ ∞ norm as a suitable contrast function for antisparse bounded sources, showcasing its superior performance relative to a state-of-the-art algorithm. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
48. Source separation and classification using generative adversarial networks and weak class supervision.
- Author
-
Karamatlı, Ertuğ, Cemgil, Ali Taylan, and Kırbız, Serap
- Subjects
- *
GENERATIVE adversarial networks , *MATRIX decomposition , *NONNEGATIVE matrices , *CLASSIFICATION - Abstract
In this paper, we propose a decomposition-based weakly-supervised model that utilizes the class labels of the sources present in mixtures. We apply this weak class supervision approach to superimposed handwritten digit images using both non-negative matrix factorization (NMF) and generative adversarial networks (GANs). In this way, we can learn non-linear representations of the sources. The results of our experiments demonstrate that the proposed weakly-supervised methods are viable and mostly on par with the fully supervised baselines. The proposed joint classification and separation approach achieves a weakly-supervised source classification performance of 90.3 in terms of F1 score and outperforms the multi-label source classifier baseline of 68.2 when there are two sources. The separation performance of the proposed method is measured in terms of peak-signal-to-noise-ratio (PSNR) as 16 dB, outperforming the class-informed sparse NMF which achieves separation of two sources with a PSNR value of 13.9 dB. We show that it is possible to replace supervised training with weakly-supervised methods without performance penalty. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
49. Adaptive detectors for mismatched subspace target in clutter with lognormal texture.
- Author
-
Guo, Qiang, Liu, Lichao, Huang, Shuai, Kaliuzhnyi, Mykola, and Tuz, Vladimir
- Subjects
- *
LIKELIHOOD ratio tests , *COVARIANCE matrices , *NULL hypothesis , *FALSE alarms , *SPECKLE interference - Abstract
Due to factors such as array misalignment and waveform distortion, the target echo may not be precisely located within the nominal subspace in practical applications, resulting in mismatch issues. In response to this challenge, this paper investigates adaptive detection methods for detecting mismatched subspace targets amidst lognormal clutter background. To enhance the suppression of mismatched signal, we introduce a fictitious signal into the null hypothesis, which is situated within a subspace orthogonal to the nominal subspace in the whitened observation space. Following convention, we allow for the existence of a training dataset that shares the same covariance matrix (CM) structure as the main dataset. Subsequently, we propose two adaptive subspace detectors based on a two-step Generalized Likelihood Ratio Test (GLRT) and a two-step maximum a posteriori (MAP) GLRT. Both novel detectors have been validated to have constant false alarm rate (CFAR) properties for speckle CM. Numerical experiments are carried out using simulation data and measured sea clutter data, which demonstrate that our proposed methods exhibit robustness against non-mismatched signal and effective suppression of mismatches. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
50. CBHQD: A channel state information-based passive line-of-sight human queue detection.
- Author
-
Guo, Yufan, Fei, Rong, Li, Junhuai, Wan, Yuxin, Yang, Chenyu, Zhao, Zhongqi, Khan, Majid Habib, and Li, Mingyue
- Subjects
- *
OPTIMIZATION algorithms , *TIME series analysis , *SIGNALS & signaling , *CROWDS , *HUMAN beings - Abstract
As the number of monitored individuals rises and multipath effects disrupt signals, existing queue monitoring solutions fail to meet efficiency needs. This paper proposes a passive line-of-sight (LOS) human queue detection method based on channel state information (CSI), namely CBHQD. We present a novel time series crowd detection network (TSCD-Net), incorporating genetic algorithm, LSTM, and FC layers to automatically extract amplitude and phase features from CSI, enhancing the simulation of indoor conditions. The genetic algorithm effectively addresses the challenge of local optima, while the fully connected layers excel in dimension reduction, facilitating the integration of valuable information obtained from LSTM. Additionally, we design the Fresnel zone detection, merging the Fresnel zone model with WiFi to estimate people's walking direction, thereby maximizing the accuracy performance of crowd detection. Lastly, we validate the feasibility and efficiency of our approach in a realistic testbed, demonstrating its suitability for detecting larger numbers of individuals. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.