arXiv subjects

Jianyong Chen

Publications and source records attributed to Jianyong Chen.

12 recordsLinked to original sources

arXiv2025

SDTN and TRN: Adaptive Spectral-Spatial Feature Extraction for Hyperspectral Image Classification

Hyperspectral image classification plays a pivotal role in precision agriculture, providing accurate insights into crop health monitoring, disease detection, and soil analysis. However, traditional methods struggle with high-dimensional data, spectral-spatial redundancy, and the scarcity of labeled samples, often leading to suboptimal performance. To address these challenges, we propose the Self-Adaptive Tensor- Regularized Network (SDTN), which combines tensor decomposition with regularization mechanisms to dynamically adjust tensor ranks, ensuring optimal feature representation tailored to the complexity of the data. Building upon SDTN, we propose the Tensor-Regularized Network (TRN), which integrates the features extracted by SDTN into a lightweight network capable of capturing spectral-spatial features at multiple scales. This approach not only maintains high classification accuracy but also significantly reduces computational complexity, making the framework highly suitable for real-time deployment in resource-constrained environments. Experiments on PaviaU datasets demonstrate significant improvements in accuracy and reduced model parameters compared to state-of-the-art methods.

cs.CV↗

arXiv2024

Coexistence of ferroelectricity and superconductivity in a two-dimensional monolayer

The coupling of ferroelectricity (FE) and superconductivity (SC) becomes the frontier of condensed matter research recently especially in the realm of two-dimensional (2D) materials. Identifying a general strategy to realize coexistence of FE and SC in a single material is extremely important for this active field, but quite challenging thus far. We show in this work that coexistence of robust FE and metallicity/SC can be realized by hole-doping a ferroelectric insulator which hosts antibonding highest valence bands (HVB). Using typical 2D ferroelecrtic SnS monolayer as a concrete example, we demonstrate that 0.30 hole/cell doping leads to enhancement of total polarization mainly ascribed to the increasing of polar displacement and ionic polarization. In addition, due to the strong Fermi surface nesting and prominent softening of out-of-plane acoustic phonon upon hole-doping, SnS can be turned into a single gap superconductor with an unexpectedly high transition temperature (Tc) of ~7 K, whereas the polar phonon mode gives negligible contribution to electron-phonon couplings. Our work provides general principle and realistic material for realizing metallic FE and superconducting FE, which paves the way for reversible and nonvolatile superconducting devices.

cond-mat.supr-con↗

arXiv2024

Ferroelectricity-tuned band topology and superconductivity in two-dimensional materials and related heterostructures

Ferroelectricity, band topology, and superconductivity are respectively local, global, and macroscopic properties of quantum materials, and understanding their mutual couplings offers unique opportunities for exploring rich physics and enhanced functionalities. In this mini-review, we attempt to highlight some of the latest advances in this vibrant area, focusing in particular on ferroelectricity-tuned superconductivity and band topology in two-dimensional (2D) materials and related heterostructures. We will first present results from predictive studies of the delicate couplings between ferroelectricity and topology or superconductivity based on first-principles calculations and phenomenological modeling, with ferroelectricity-enabled topological superconductivity as an appealing objective. Next, we will cover the latest advances on experimental studies of ferroelectricity-tuned superconductivity based on different 2D materials or van der Waals heterostructures. Finally, as perspectives, we will outline schemes that may allow to materialize new types of 2D systems that simultaneously harbor ferroelectricity and superconductivity, or that may lead to enhanced ferroelectric superconductivity, ferroelectric topological superconductivity, and new types of superconducting devices such as superconducting diodes.

cond-mat.supr-con↗

arXiv2024

VCformer: Variable Correlation Transformer with Inherent Lagged Correlation for Multivariate Time Series Forecasting

Multivariate time series (MTS) forecasting has been extensively applied across diverse domains, such as weather prediction and energy consumption. However, current studies still rely on the vanilla point-wise self-attention mechanism to capture cross-variable dependencies, which is inadequate in extracting the intricate cross-correlation implied between variables. To fill this gap, we propose Variable Correlation Transformer (VCformer), which utilizes Variable Correlation Attention (VCA) module to mine the correlations among variables. Specifically, based on the stochastic process theory, VCA calculates and integrates the cross-correlation scores corresponding to different lags between queries and keys, thereby enhancing its ability to uncover multivariate relationships. Additionally, inspired by Koopman dynamics theory, we also develop Koopman Temporal Detector (KTD) to better address the non-stationarity in time series. The two key components enable VCformer to extract both multivariate correlations and temporal dependencies. Our extensive experiments on eight real-world datasets demonstrate the effectiveness of VCformer, achieving top-tier performance compared to other state-of-the-art baseline models. Code is available at this repository: https://github.com/CSyyn/VCformer.

cs.LG↗

arXiv2024

Large Language Model-Aided Evolutionary Search for Constrained Multiobjective Optimization

Evolutionary algorithms excel in solving complex optimization problems, especially those with multiple objectives. However, their stochastic nature can sometimes hinder rapid convergence to the global optima, particularly in scenarios involving constraints. In this study, we employ a large language model (LLM) to enhance evolutionary search for solving constrained multi-objective optimization problems. Our aim is to speed up the convergence of the evolutionary population. To achieve this, we finetune the LLM through tailored prompt engineering, integrating information concerning both objective values and constraint violations of solutions. This process enables the LLM to grasp the relationship between well-performing and poorly performing solutions based on the provided input data. Solution's quality is assessed based on their constraint violations and objective-based performance. By leveraging the refined LLM, it can be used as a search operator to generate superior-quality solutions. Experimental evaluations across various test benchmarks illustrate that LLM-aided evolutionary search can significantly accelerate the population's convergence speed and stands out competitively against cutting-edge evolutionary algorithms.

cs.NE↗

arXiv2024

An End-to-End Structure with Novel Position Mechanism and Improved EMD for Stock Forecasting

As a branch of time series forecasting, stock movement forecasting is one of the challenging problems for investors and researchers. Since Transformer was introduced to analyze financial data, many researchers have dedicated themselves to forecasting stock movement using Transformer or attention mechanisms. However, existing research mostly focuses on individual stock information but ignores stock market information and high noise in stock data. In this paper, we propose a novel method using the attention mechanism in which both stock market information and individual stock information are considered. Meanwhile, we propose a novel EMD-based algorithm for reducing short-term noise in stock data. Two randomly selected exchange-traded funds (ETFs) spanning over ten years from US stock markets are used to demonstrate the superior performance of the proposed attention-based method. The experimental analysis demonstrates that the proposed attention-based method significantly outperforms other state-of-the-art baselines. Code is available at https://github.com/DurandalLee/ACEFormer.

q-fin.ST↗

arXiv2022

Ferroelectric tuning of superconductivity and band topology in a two-dimensional heterobilayer

Realization of tunable superconductivity with concomitant nontrivial band topology is conceptually intriguing and highly desirable for superconducting devices and topological quantum computation. Based on first-principles calculations, here we present the first prediction of simultaneously tunable superconducting transition temperature (Tc) and band topology in a superconducting IrTe2 overlayer on a ferroelectric In2Se3 monolayer. We first demonstrate that the Tc is substantially enhanced from that of IrTe2 nanoflakes (Tc ~3 K) due to significant charge repartitioning around the Fermi level. More importantly, the Tc is shown to sensitively depend on the In2Se3 polarization, with the higher Tc of ~(8-10) K attributed to enhanced interlayer electron-phonon coupling when the polarization is downward. The band topology is also switched from trivial to nontrivial as the polarization is reversed from upward to downward. These findings provide physically realistic platforms for simultaneously tuning superconductivity and band topology in two-dimensional heterobilayers and related heterostructures using a reversible and nonvolatile approach.

cond-mat.supr-con↗

arXiv2021

MMOCR: A Comprehensive Toolbox for Text Detection, Recognition and Understanding

We present MMOCR-an open-source toolbox which provides a comprehensive pipeline for text detection and recognition, as well as their downstream tasks such as named entity recognition and key information extraction. MMOCR implements 14 state-of-the-art algorithms, which is significantly more than all the existing open-source OCR projects we are aware of to date. To facilitate future research and industrial applications of text recognition-related problems, we also provide a large number of trained models and detailed benchmarks to give insights into the performance of text detection, recognition and understanding. MMOCR is publicly released at https://github.com/open-mmlab/mmocr.

cs.CV↗

arXiv2021

Strong electron-phonon coupling in 3D tungsten nitride and coexistence of intrinsic superconductivity and topological nodal line in its 2D limit

Three-component fermion beyond the conventional Dirac Weyl Majorana classification attracts extensive attentions recently and many efforts have been paid to explore their superconductivity. Based on first-principles calculations, we systematically investigate the electron-phonon coupling (EPC) in the three-component fermion materials WN, WC and TaN. The EPC in pristine and pressured WC and TaN are to small to induce superconductivity. Electron doping can efficiently enhance the EPC strength and the predicted Tcs reach the value of experiments. Upon 0.6 electron/unitcell doping, the EPC strength of TaN is boosted by two orders of magnitude and Tc can even be as high as 27 K, revealing the crucial role of charge doping in the formation of superconductivity observed in WC and TaN. In stark contrast, pristine WN exhibits overwhelmingly strong EPC and can be a good superconductor with a high transition temperature Tc of 31 K. The strong EPC in WN are dictated by a synergistic effect of strong Fermi nesting and large deformation potential. Going down from three-dimension (3D) to three-dimension (2D), WN thin film (i.e. monolayer W3N4) is also an intrinsic superconductor with Tc of 11 K. Most importantly, monolayer W3N4 host Dirac nodal lines protected by mirror symmetry in the absence of spin-orbit coupling (SOC), Including SOC, the Dirac nodal lines split into three pairs of spinful Weyl rings. These nodal lines lies closely near the Fermi level, they are pure and clean without other nontrivial bands, which is scarce in real materials and making the exotic topological properties easily accessible in experiment. The coexistence of superconductivity with high transition temperature and topological states in WN and its 2D film provide a promising platform for exploring topological superconductivity.

cond-mat.supr-con↗

arXiv2021

Fourier Contour Embedding for Arbitrary-Shaped Text Detection

One of the main challenges for arbitrary-shaped text detection is to design a good text instance representation that allows networks to learn diverse text geometry variances. Most of existing methods model text instances in image spatial domain via masks or contour point sequences in the Cartesian or the polar coordinate system. However, the mask representation might lead to expensive post-processing, while the point sequence one may have limited capability to model texts with highly-curved shapes. To tackle these problems, we model text instances in the Fourier domain and propose one novel Fourier Contour Embedding (FCE) method to represent arbitrary shaped text contours as compact signatures. We further construct FCENet with a backbone, feature pyramid networks (FPN) and a simple post-processing with the Inverse Fourier Transformation (IFT) and Non-Maximum Suppression (NMS). Different from previous methods, FCENet first predicts compact Fourier signatures of text instances, and then reconstructs text contours via IFT and NMS during test. Extensive experiments demonstrate that FCE is accurate and robust to fit contours of scene texts even with highly-curved shapes, and also validate the effectiveness and the good generalization of FCENet for arbitrary-shaped text detection. Furthermore, experimental results show that our FCENet is superior to the state-of-the-art (SOTA) methods on CTW1500 and Total-Text, especially on challenging highly-curved text subset.

cs.CV↗

arXiv2018

High-dimensional cryptographic quantum parameter estimation

We investigate cryptographic quantum parameter estimation with a high-dimensional system that allows only Bob (Receiver) to access the result and achieve optimal parameter precision from Alice (Sender). Eavesdropper (Eve) only can disturb the parameter estimation of Bob, but she can not obtain the information of parameter. We analyze the security and show that the high-dimensional system can help to utilize the resource to obtain better precision than the two-dimensional system. Finally, we generalize it to the case of multi-parameter.

quant-ph↗

arXiv2017

Quantum estimation of detection efficiency with no-knowledge quantum feedback

We investigate that no-knowledge measurement-based feedback control is utilized to obtain the estimation precision of the detection efficiency. For the feedback operators that concern us, no-knowledge measurement is the optimal way to estimate the detection efficiency. We show that the higher precision can be achieved for the lower or larger detection efficiency. It is found that no-knowledge feedback can be used to cancel decoherence. No-knowledge feedback with a high detection efficiency can perform well in estimating frequency and detection efficiency parameters simultaneously. And simultaneous estimation is better than independent estimation given by the same probes.

quant-ph↗