检索结果-内蒙古大学图书馆

Enhanced scattering from an almost-periodic optical temporal slab

Physical Review A 2024年第4期110卷 L041501页

作者： Stefanos Fr. Koufidis Theodoros T. Koutserimpas Francesco Monticone Martin W. McCall Blackett Laboratory Department of Physics School of Electrical and Computer Engineering

We showcase the impact of almost-periodicity on the parametric amplification associated with the first-order momentum gap in photonic time-crystals with time-varying permittivity. Utilizing a vectorial coupled-wave theory approach, we rigorously analyze the scattering by a temporal slab of the considered medium. We pinpoint a critical regime wherein flaws in material tuning paradoxically enhance amplification due to the coupling of fewer, broader modes, resulting in a higher and broader pulselike amplification envelope. Additionally, we demonstrate that the intensity reflectances of time-reversed waves corresponding to secondary “Bragg” resonances achieve remarkably high levels of subharmonic parametric amplification, with the epsilon-near-zero regime serving as a preferred candidate for experimental implementation. Our counterintuitive findings highlight the potential of intentionally leveraging modulation desynchronization and impurities in the temporal unit cell of photonic time-crystals to enhance both the level and the bandwidth of amplification.

关键词： Light propagation, transmission & absorption Metamaterials Time crystals Bragg structures Optical parametric oscillators & amplifiers Perturbative methods Rigorous coupled-wave analysis

来源：评论

学校读者我要写书评

暂无评论

Ensemble deep learning for high-precision classification of 90 rice seed varieties from hyperspectral images

引用

Journal of Ambient Intelligence and Humanized Computing 2024年第6期15卷 2883-2899页

作者： Taheri, AmirMasoud Ebrahimnezhad, Hossein Sedaaghi, Mohammadhossein Computer Vision Research Laboratory Faculty of Electrical Engineering Sahand University of Technology Tabriz Iran

To develop rice varieties with better nutritional qualities, it is important to classify rice seeds accurately. Hyperspectral imaging can be used to extract spectral information from rice seeds, which can then be used to classify them into different varieties. The challenges of precise classification increase when there are many classes and few training samples. In this paper, we present a novel method for high-precision Hyperspectral Image (HSI) classification of 90 different classes of rice seeds using ensemble deep learning. Our method first employs band selection techniques to select the optimal hyperspectral bands for rice seed classification. Then, a deep neural network is trained with the selected hyperspectral and RGB data from rice seed images to obtain different models for different bands. Finally, an ensemble of deep learning models is employed to classify rice seed images and improve classification accuracy. The proposed method achieves an overall precision ranging from 92.73 to 96.17% despite a large number of classes and low data samples for each class and with only 15 selected hyperspectral bands. This precision is significantly higher than the state-of-the-art classical machine learning methods like random forest, confirming the effectiveness of the proposed method in classifying hyperspectral images of rice seeds. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024.

关键词： Image classification

来源：评论

学校读者我要写书评

暂无评论

A new architecture based resnet for steganography in color images

引用

Multimedia Tools and Applications 2025年第16期84卷 16229-16248页

作者： Hashemi, Seyed Hesam Odin Majidi, Mohammad-Hassan Khorashadizadeh, Saeed Faculty of Electrical and Computer Engineering University of Birjand Birjand Iran

This paper proposes a deep-learning color image steganography scheme that employs convolutional autoencoders with ResNet architecture. In the proposed method, all images are passed through the Preproccessing model which is a convolutional deep neural network with the aim of feature extraction. Then, the Operational model generates the stego or extracted image. The advantage of the proposed structure is the identity of models in the embedding and extraction phases. The performance of the proposed method is studied using COCO and CelebA datasets. For quantitative comparisons with previous related works, the peak signal-to-noise ratio (PSNR), the structural similarity index (SSIM), and hiding capacity are evaluated. The experimental results verify that the proposed scheme performs better than traditional and previous deep steganography methods. The PSNR and SSIM are more than 35dB and 0.98, respectively which implies the high imperceptibility of the proposed method. Also, the relative capacity of the proposed method is 8 bits per pixel. To assess the robustness of the proposed scheme against various steganalysis methods, we conducted histogram, difference, and stag analyses. The outcomes demonstrated that the proposed scheme could withstand different kinds of attacks. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2024.

关键词： Steganography

来源：评论

学校读者我要写书评

暂无评论

Valid-IoU: an improved IoU-based loss function and its application to detection of defects on printed circuit boards

引用

Multimedia Tools and Applications 2025年第14期84卷 13905-13928页

作者： Vakili, Elnaz Karimian, Ghader Shoaran, Maryam Yadipour, Reza Sobhi, Jafar Faculty of Electrical and Computer Engineering University of Tabriz Tabriz Iran

The printed circuit boards (PCBs) should be inspected during the manufacturing process to minimize defects such as printing errors, incorrect component selections, and incorrect soldering. Convolutional neural networks (CNNs) have emerged as a powerful tool for this purpose, owing to their robust recognition capabilities. However, the accuracy of CNNs is significantly influenced by the choice of loss function. Intersection over Union (IoU) based loss functions commonly employed for bounding box regression, achieve remarkable success, but still have some main drawbacks such as inaccurate predicting bounding box dimensions relative to ground truth data. In this paper, we propose an improved IoU called Valid-IoU (VIoU) to solve this problem. We integrated the VIoU loss into state-of-the-art YOLO object detection frameworks to show its effectiveness in PCB defect detection. The experimental results on the HRIPCB PCB dataset demonstrate that the VIoU loss has high defect detection accuracy. Using YOLOv4 helped us to improve average accuracy, and with YOLOv8, we achieved faster detection speed compared to other methods. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2024.

关键词： Object detection

来源：评论

学校读者我要写书评

暂无评论

Design of a Flux-Barrier Permanent Magnet Vernier Motor with a Flux Modulation Ring to Enhance Torque Production and Efficiency Factor

引用

International Journal of engineering, Transactions B: Applications 2025年第6期38卷 1369-1378页

作者： Imanifar, A. Yaghobi, H. Faculty of Electrical and Computer Engineering Semnan University Semnan Iran

Flux-barrier permanent magnet Vernier motors are among the latest magnetic motors developed and optimized in the industry. In these motors, the arrangement of magnets plays a critical role and significantly impacts on the torque density in the rotor-stator gap. This is because the motor's output torque increases with an enhancement of magnetic flux intensity in this gap. The magnetic gearbox effect in the flux-barrier permanent magnet Vernier motors, along with flux modulation, is one of the most critical factors in the design and construction of these motors. Flux modulation in the air-gap generates high torque at low speeds. In this study, inspired by the concept of magnetic gearboxes and by adding a modulation ring to the air-gap of this motor, a novel design for flux-barrier permanent magnet Vernier motors with a gearbox is presented. Using the two-dimensional finite element method (FEM), it has been demonstrated that the designed motor achieves significant improvements in average output torque and power factor compared to previous designs. ©2025 The author(s).

关键词： Permanent magnets

来源：评论

学校读者我要写书评

暂无评论

Secure speech coding using chaotic shift keying for encryption combined with error recovery

引用

Multimedia Tools and Applications 2025年第7期84卷 3893-3927页

作者： Boumaraf, Messaouda Merazka, Fatiha LISIC Laboratory Telecommunications Department Electronic and Computer Engineering Faculty USTHB University Algiers Algeria LISIC Laboratory Telecommunications Department Electrical Engineering Faculty USTHB University Algiers Algeria

This paper presents a speech encryption algorithm utilizing chaotic shift keying alongside error recovery techniques for the G.722.2 codec. The algorithm employs chaotic data interleaving on speech inter-frames to replace continuous packet loss with isolated losses, thus restoring missing data packets. Codec parameters undergo encryption through the combination of multiple chaotic maps applied to intra sub-frames of speech, facilitating confusion and diffusion processes. Enhanced security is achieved through the utilization of multiple chaotic maps, including chaotic shift keying generators applied to codec sub-frame parameters. Specifically, the chaotic shift keying mechanism is employed using four chaotic maps: a Henon map for xn and yn, a logistic map for zn, a tent map for wn, and a cubic map for un. The keys derived from these maps are utilized for chaotic data interleaving on both inter-frames and intra sub-frames of the speech file to shuffle frame parameters (confusion) and scramble sub-frame parameters (diffusion). Additionally, the proposed system enhances speech quality by mitigating degradation caused by packet loss through a waveform substitution-based recovery method, which replaces lost packets with previously received copies. A series of experiments, including waveform representation, spectrogram analysis, Enhanced Modified Bark Spectral Distortion (EMBSD) test, WideBand Perceptual Evaluation of Speech Quality (WB-PESQ) test, MUltiple Stimuli with Hidden Reference and Anchor (MUSHRA) score, Mean Opinion Score (MOS) score, correlation test, entropy test, Number of Samples Change Rate (NSCR) test, Unified Average Modified Intensity (UACI) test, key space analysis, and sensitivity test, are conducted to evaluate the security and speech quality of the proposed system. The results validate the system’s security and confirm its ability to maintain good audio quality even under packet loss rates ranging from 5% to 20%. © The Author(s), under exclusive licen

关键词： Cryptography

来源：评论

学校读者我要写书评

暂无评论

Computing Riemann zeros with light scattering

引用

Physical Review B 2024年第22期110卷 L220201-L220201页

作者： Sunkyu Yu Xianji Piao Namkyoo Park Intelligent Wave Systems Laboratory Department of Electrical and Computer Engineering Seoul National University Seoul 08826 Korea Wave Engineering Laboratory School of Electrical and Computer Engineering University of Seoul Seoul 02504 Korea Photonic Systems Laboratory Department of Electrical and Computer Engineering Seoul National University Seoul 08826 Korea

Finding hidden order within disorder is a common interest in material science, wave physics, and mathematics. The Riemann hypothesis, stating the locations of nontrivial zeros of the Riemann zeta function, tentatively characterizes statistical order in the seemingly random distribution of prime numbers. This famous conjecture has inspired various connections with different branches of physics, recently with non-Hermitian physics, quantum field theory, trapped-ion qubits, and hyperuniformity. Here we develop the computing platform for the Riemann zeta function by employing classical scattering of light. We show that the Riemann hypothesis suggests the landscape of semi-infinite optical scatterers for the perfect reflectionless condition under the Born approximation. To examine the validity of the scattering-based computation, we investigate the asymptotic behaviors of suppressed reflections with the increasing number of scatterers and the emergence of multiple scattering. The result provides another bridge between classical physics and the Riemann zeros, exhibiting the design of wave devices inspired by number theory.

关键词： Light scattering

来源：评论

学校读者我要写书评

暂无评论

Long-range-interacting topological photonic lattices breaking channel-bandwidth limit

引用

Light(Science & Applications) 2024年第10期13卷 2367-2375页

作者： Gyunghun Kim Joseph Suh Dayeong Lee Namkyoo Park Sunkyu Yu Department of Electrical and Computer Engineering Intelligent Wave Systems LaboratorySeoul National UniversitySeoul 08826Korea Department of Electrical and Computer Engineering Photonic Systems LaboratorySeoul National UniversitySeoul 08826Korea

The presence of long-range interactions is crucial in distinguishing between abstract complex networks and wave *** photonics,because electromagnetic interactions between optical elements generally decay rapidly with spatial distance,most wave phenomena are modeled with neighboring interactions,which account for only a small part of conceptually possible ***,we explore the impact of substantial long-range interactions in topological *** demonstrate that a crystalline structure,characterized by long-range interactions in the absence of neighboring ones,can be interpreted as an overlapped *** overlap model facilitates the realization of higher values of topological invariants while maintaining bandgap width in photonic topological *** breaking of topology-bandgap tradeoff enables topologically protected multichannel signal processing with broad *** practically accessible system parameters,the result paves the way to the extension of topological physics to network science.

关键词： topological breaking neighboring

来源：评论

学校读者我要写书评

暂无评论

Create a crowd emotion detection framework with ecological validity

引用

IEEE Transactions on Affective Computing 2024年第2期16卷 1087-1103页

作者： Chen, Xiao Liu, Zhen Liu, Tingting Xiao, Jiangjian The Faculty of Electrical Engineering and Computer Science Ningbo University China

Ecological validity remains essential for generalizing scientific research into real-world applications. However, current methods for crowd emotion detection lack ecological validity due to limited diversity samples in datasets. This paper proposes a crowd emotion detection framework that improves the ecological validity of models from both dataset and methodological perspectives. Firstly, we develop an Emotional Crowd Generator script within Grand Theft Auto V to generate a large-scale and diverse synthetic emotional crowd dataset, named Emotional-GTA (E-GTA). Secondly, we utilize prior features to enhance the model's generalization ability, especially for rare samples. Building on this, we introduce the dual-driven Graph-based Prior feature and Image Fusion Network (GPIFN), which further strengthens our model's ecological validity from a methodological perspective. We propose a graphical representation that effectively constructs the Crowd Image Graph (CIG) and the Crowd Prior Features Graph (CPG), which represent crowds from the perspectives of image and prior features, respectively. We then design a dual-stream network GPIFN that extracts image features from the CIG and prior features from the CPG. Additionally, we design an Image and Prior features Fusion Module (IPFM) that efficiently merges image and prior features while preserving the original stream features. Our experiments demonstrate that both E-GTA and GPIFN greatly enhance ecological validity in real-world scenarios. Our framework achieves state-of-the-art results on real-world datasets: UMN and Violent-Flows. © 2010-2012 IEEE.

关键词： Emotion Recognition

来源：评论

学校读者我要写书评

暂无评论

NeuroQuMan: quantum neural network-based consumer reaction time demand response predictive management

引用

Neural Computing and Applications 2024年第30期36卷 19121-19138页

作者： Safari, Ashkan Badamchizadeh, Mohammad Ali Faculty of Electrical and Computer Engineering University of Tabriz Tabriz Iran

Demand response, and artificial intelligence integration with it, have a considerable effect in optimizing energy consumption, grid stability, and promoting sustainable energy practices. Consequently, this paper presents NeuroQuMan, a comprehensive methodology for simulating demand response using a three-Qubit quantum neural network (QNN) model. NeuroQuMan integrates quantum computing and machine learning techniques to accurately predict demand based on user reaction time. The methodology encompasses an advanced structure that includes data preprocessing, three-Qubit quantum device initialization, quantum circuit definition, user decision-making, QNN predictions, loss calculations, and visualization. During the tests, NeuroQuMan achieved considerable performance values of metrics, with RMSPE of 5.41%, MAPE of 4.43%, as well as MAE of 0.37, RMSE of 0.45, and MSE of 0.21, respectively. These metrics manifest the accuracy and effectiveness of NeuroQuMan in predicting demand response. By the side of future perspectives of the work, it explores the application of advanced quantum techniques to further enhance prediction accuracy. NeuroQuMan represents the potential of quantum computing in addressing demand response challenges and provides a pathway toward more resilient and intelligent energy management systems. The findings and framework presented in this paper are utilized to advance the field of demand response and quantum-based energy management techniques using a three-Qubit structure. © The Author(s), under exclusive licence to Springer-Verlag London Ltd., part of Springer Nature 2024.

关键词： Forecasting

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：