Electrocardiogram (ECG) based user identification has received considerable attention with the advent of wearable devices. It provides emerging applications including personal healthcare a convenient way to authentica...
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We theoretically investigate the second harmonic generation (SHG) of Dirac or Weyl semimetals under parallel DC electric and strong magnetic fields using the Boltzmann equation approach. The DC current-induced SHG pro...
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We theoretically investigate the second harmonic generation (SHG) of Dirac or Weyl semimetals under parallel DC electric and strong magnetic fields using the Boltzmann equation approach. The DC current-induced SHG process originates from the optical intraband transitions of the Landau subbands. It is a remarkable fingerprint of three-dimensional Dirac or Weyl dispersions and absent in other materials. An analytical formula for the SHG tensor is derived, and it shows chirality independence. The second-order nonlinear optical susceptibility is proportional to the DC field, giving strong optical nonlinearity up to 105pm/V with THz light, which is several orders larger than that of the usual materials. More interesting, the second harmonic conductivity is found to exhibit periodicity in magnetic field 1/B oscillations, which are similar to the Shubnikov–de Haas oscillations. Thus our work proposes another approach for SHG and potential applications of Dirac or Weyl semimetals in nonlinear optics.
The mining industry is the source of the production of many consumer goods and equipment. Therefore, the companies that control this activity play a significant role in the global economy. However, it is an important ...
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Although current data augmentation methods are successful to alleviate the data insufficiency, conventional augmentation are primarily intra-domain while advanced generative adversarial networks (GANs) generate images...
Although current data augmentation methods are successful to alleviate the data insufficiency, conventional augmentation are primarily intra-domain while advanced generative adversarial networks (GANs) generate images remaining uncertain, particularly in small-scale datasets. In this paper, we propose a parameterized GAN (ParaGAN) that effectively controls the changes of synthetic samples among domains and highlights the attention regions for downstream classification. Specifically, ParaGAN incorporates projection distance parameters in cyclic projection and projects the source images to the decision boundary to obtain the class-difference maps. Our experiments show that ParaGAN can consistently outperform the existing augmentation methods with explainable classification on two small-scale medical datasets.
Based on the rising incidences of crime and violence, it has become a matter of general importance that technology may be developed to automatically detect the presence of violence in the surveillance footage. For law...
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ISBN:
(纸本)9781450387347
Based on the rising incidences of crime and violence, it has become a matter of general importance that technology may be developed to automatically detect the presence of violence in the surveillance footage. For law enforcement, the detection of violent incidents can play an important role in urban safety. The efficiency of event detectors is usually measured in terms of detection speed, precision, and generality over many types of video inputs in a distinct format. However, various recent studies in this area have either focused on the correctness of the model, its response speed, or both, but have missed on considering the multiple data sources for effective model analysis. The main objective of the work is to propose a real-time violence event identifier based on state-of-the-art deep learning methods. Primarily the proposed model is based on the ViT (Vision Transformer) architecture, while other models like ConvLSTM and VGG16 with LSTM were also explored in this work. Two benchmark datasets viz. the RLVS (Real Life Violence Situations) and the Hockey fight datasets were used in this work for robust training and test analysis of the proposed model. For evaluating the model’s performance various metrics including accuracy, f1-score, precision, and recall were evaluated. The results show that the Vision Transformer-based model outperformed all the explored models with an overall accuracy of 98% and 97% on the RLVS dataset and the Hockey datasets respectively, which are also significantly higher than the recent solutions proposed on these datasets.
The prevalence of stress and boredom in contempo-rary culture substantially influences mental health and overall well-being. Identifying activities associated with these emotional states is essential to implement effe...
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ISBN:
(数字)9798350363517
ISBN:
(纸本)9798350363524
The prevalence of stress and boredom in contempo-rary culture substantially influences mental health and overall well-being. Identifying activities associated with these emotional states is essential to implement effective treatments and support systems. This research presents a new method for identifying stress and boredom activities using wristwatch sensor data and a hybrid deep learning model called CNN-ResBiGRU-CBAM. This model utilizes convolutional neural networks (CNN s), residual bidirectional gated recurrent units (GRUs), and a convolutional block attention module (CBAM) to acquire knowledge about spatial and temporal characteristics and comprehend intricate patterns in sensor input. The experimental results underscore the practical application of the proposed model in the field of affective computing and mental health monitoring. This model not only outperforms both traditional and state-of-the-art deep learning models in accurately identifying stress and boredom behaviors, but also demonstrates its adaptability in leave-one-subject-out validation. With an impressive accuracy of 99.47 % and an F1-score of 99.44% in 5-fold cross-validation, this model shows promise in acquiring features that are relevant to different individuals, thereby enhancing the field of affective computing and mental health monitoring through the use of wearable devices.
Control design for linear, time-invariant mechanical systems typically requires an accurate low-order approximation in the low frequency range. For example a series expansion of the transfer function around zero consi...
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Just as electronic shot noise in driven conductors results from the granularity of charge and the statistical variation in the arrival times of charge carriers, there are predictions for fundamental noise in magnon cu...
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Just as electronic shot noise in driven conductors results from the granularity of charge and the statistical variation in the arrival times of charge carriers, there are predictions for fundamental noise in magnon currents due to angular momentum being carried by discrete excitations. The inverse spin Hall effect as a transduction mechanism to convert spin current into charge current raises the prospect of experimental investigations of such magnon shot noise. Spin Seebeck effect measurements have demonstrated the electrical detection of thermally driven magnon currents and have been suggested as an avenue for accessing spin current fluctuations. Using spin Seebeck structures made from yttrium iron garnet on gadolinium gallium garnet, we demonstrate the technical challenges inherent in such noise measurements. While there is a small increase in voltage noise in the inverse spin Hall detector at low temperatures associated with adding a magnetic field, the dependence on field orientation implies that this is not due to magnon shot noise. We describe theoretical predictions for the expected magnitude of magnon shot noise, highlighting ambiguities that exist. Further, we show that magnon shot noise detection through the standard inverse spin Hall approach is likely impossible due to geometric factors. Implications for future attempts to measure magnon shot noise are discussed.
Predicting reactants from a specified core product stands as a fundamental challenge within organic synthesis, termed retrosynthesis prediction. Recently, semi-template-based methods and graph-edits-based methods have...
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Ontologies are a standard tool for creating semantic schemata in many knowledge intensive domains of human interest. They are becoming increasingly important also in the areas that have been until very recently domina...
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