arXiv subjects

Jinxing Yang

Publications and source records attributed to Jinxing Yang.

5 recordsLinked to original sources

arXiv2025

Rapid morphology characterization of two-dimensional TMDs and lateral heterostructures based on deep learning

Two-dimensional (2D) materials and heterostructures exhibit unique physical properties, necessitating efficient and accurate characterization methods. Leveraging advancements in artificial intelligence, we introduce a deep learning-based method for efficiently characterizing heterostructures and 2D materials, specifically MoS2-MoSe2 lateral heterostructures and MoS2 flakes with varying shapes and thicknesses. By utilizing YOLO models, we achieve an accuracy rate of over 94.67% in identifying these materials. Additionally, we explore the application of transfer learning across different materials, which further enhances model performance. This model exhibits robust generalization and anti-interference ability, ensuring reliable results in diverse scenarios. To facilitate practical use, we have developed an application that enables real-time analysis directly from optical microscope images, making the process significantly faster and more cost-effective than traditional methods. This deep learning-driven approach represents a promising tool for the rapid and accurate characterization of 2D materials, opening new avenues for research and development in material science.

cs.LG↗

arXiv2024

Level of Regions for Deformed Braid Arrangements

This paper primarily investigates a specific type of deformation of the braid arrangement $\mathcal{B}_n$ in $\mathbb{R}^n$, denoted by $\mathcal{B}_n^A$ and defined in (1.2). Let $r_l(\mathcal{B}_n^A)$ be the number of regions of level $l$ in $\mathcal{B}_n^A$ with the corresponding exponential generating function $R_l(A;x)$. Using the weighted digraph model introduced by Hetyei [11], we establish a bijection between regions of level $l$ in $\mathcal{B}_n^A$ and valid $m$-acyclic weighted digraphs on the vertex set $[n]$ with exactly $l$ strong components. Based on this bijection, we obtain a property analogous to a polynomial sequence of binomial type, that is, $R_l(A;x)$ satisfies the relation \[ R_l(A;x)=\big(R_1(A;x)\big)^l=R_k(A;x)R_{l-k}(A;x). \] Furthermore, the values $r_l(\mathcal{B}_n^A)$ yield a combinatorial interpretation for the coefficients in the expansion of the characteristic polynomial $\chi_{\mathcal{B}_n^A}(t)$ in the basis elements $\binom{t}{l}$, that is, \[\chi_{\mathcal{B}_n^A}(t)=\sum_{l=0}^n(-1)^{n-l}r_l(\mathcal{B}_n^A)\binom{t}{l}.\] If $n$, $a$ and $b$ are non-negative integers with $n\ge 2$ and $b-a\ge n-1$, for the deformation $\mathcal{B}_n^{[-a,b]}$ defined in (1.3), its characteristic polynomial has a single real root $0$ of multiplicity one when $n$ is odd, and has one more real root $\frac{n(a+b+1)}{2}$ of multiplicity one when $n$ is even.

math.CO↗

arXiv2024

Level Decompositions for Symmetric Deformations of the Braid Arrangement

Let $A\subseteq\mathbb R_{\ge0}$ be finite and nonempty, and let $\mathfrak{A}^A=(\mathcal{A}_1^A,\mathcal{A}_2^A,\ldots)$ be the associated sequence of symmetric deformations of the braid arrangement. Denote by $r_\ell(\mathcal{A}_n^A)$ the number of its level-$\ell$ regions and by $F_\ell(\mathfrak{A}^A,x)$ the corresponding exponential generating function. We prove $F_\ell(\mathfrak{A}^A,x)=\bigl(F_1(\mathfrak{A}^A,x)\bigr)^\ell$. As a consequence, the characteristic polynomial has the binomial-basis expansion $\chi(\mathcal{A}_n^A,t)=\sum_{\ell=1}^{n}(-1)^{n-\ell}\,r_\ell(\mathcal{A}_n^A)\binom{t}{\ell}$. When $0\in A$ and $A^*=A\setminus\{0\}$ is nonempty, we refine a classical identity of Stanley level by level: $F_\ell(\mathfrak{A}^{A^*},x)=F_\ell(\mathfrak{A}^{A},1-e^{-x})$. Equivalently, the Catalan-type and semiorder-type level counts satisfy an unsigned Stirling convolution of the first kind. For the $m$-Catalan arrangement $\mathcal{A}_n^{[0,m]}$, we obtain $r_\ell(\mathcal{A}_n^{[0,m]})=n!\,\operatorname{Ran}_{m+1,m\ell}(n-\ell)$, where $\operatorname{Ran}_{p,r}(q)$ is a Raney number. This realizes Raney numbers as refined region counts and answers a question of Deshpande, Menon, and Sarkar. The proofs use labeled Dyck paths, interval orders, and exponential sequences of arrangements. We also realize the inverse Fu--Wang--Zhu bijection for $m$-Catalan regions by tableaux.

math.CO↗

arXiv2024

Two Bijections on NBC Subsets

We establish two explicit bijections: from acyclic reorientations of an oriented matroid to no broken circuit (NBC) subsets of its underlying matroid, and from regions of a real hyperplane arrangement to its affine NBC subsets.

math.CO↗

arXiv2022

Low-complexity Beam Selection algorithms based on SVD for MmWave Massive MIMO Systems

To realize mmWave massive MIMO systems in practice, Beamspace MIMO with beam selection provides an attractive solution at a considerably reduced number of radio frequency (RF) chains. We propose low-complexity beam selection algorithms based on singular value decomposition (SVD). We first diagonalize the channel matrix by SVD, and the appropriate beams are selected one-by-one in a decremental or incremental order based on the criterion of sum-rate maximization. To reduce the complexity of the proposed algorithms significantly, we make use of SVD in the last iteration to aviod SVD from scratch again. Meanwhile, our proposed algorithms naturally obtain the precoding matrix, which can eliminate the multiusers interference. Simulation results demonstrate that our proposed algorithms can outperform the competing algorithms, including the fully digital zero-precoding.

cs.IT↗