Explanipedia

ggincerta: Extend 'ggplot2' with Layers and Scales for Spatial Uncertainty Visualization Open

Xuanlong Ma, Emi Tanaka · 2025

Aspects of the commuting graph Open

V. Arvind, Peter J‎. Cameron, Xuanlong Ma, Н. В. Маслова · 2025

Unveiling hidden dynamics: fine-scale mapping of groundwater-dependent ecosystems using multi-source Earth observations Open

Yu Liang, Chunyan Cao, Xiaoyu Zhu, Sicong Gao, Yongqiang Zhang , et al. · 2025

Groundwater-dependent ecosystems (GDEs) provide valuable ecosystem services but are threatened by climate change and increased human groundwater use. Sustainable groundwater management requires knowledge of the spatial distribution of GDEs…

Which coprime graphs are divisor graphs? Open

Xuanlong Ma, Liangliang Zhai, Nan Gao · 2025

For a finite group $G$, the coprime graph $Γ(G)$ of $G$ is a graph with vertex set $G$, in which two distinct vertices $a$ and $b$ are adjacent if the order of $a$ and the order of $b$ are coprime. In this paper, we first give a characteri…

Green's graphs of a semigroup Open

Yanliang Cheng, Yong Shao, Xuanlong Ma · 2025

Let S S be a semigroup. In this study, we first introduce the Green’s digraphs and Green’s graphs related to the Green’s relations L {\mathscr{L}} , R {\mathscr{R}} , and J {\mathscr{J}} of S S . Further, the connectedness and co…

(Total) Perfect codes in (extended) subgroup sum graphs Open

Xuanlong Ma, Yuefeng Yang, Liangliang Zhai · 2024

Given a finite group $G$ with identity $e$ and a normal subgroup $H$ of $G$, the subgroup sum graph $Γ_{G,H}$ (resp. extended subgroup sum graph $Γ_{G,H}^+$) of $G$ with respect to $H$ is the graph with vertex set $G$, in which distinct ve…

Notes on the diameter of the complement of the power graph of a finite group Open

Xuanlong Ma, Alireza Doostabadi, Kaishun Wang · 2024

We determine the diameter of every connected component of the complement of the power graph and the enhanced power graph of a finite group, which completely answers two questions by Peter J. Cameron.

Finite groups whose commuting graph is split Open

Xuanlong Ma, Peter J‎. Cameron · 2024

As a contribution to the study of graphs defined on groups, we show that for a finite group G the following statements are equivalent: the commuting graph of G is a split graph; the commuting graph of G is a threshold graph; either G is ab…

On connected components and perfect codes of proper order graphs of finite groups Open

H. Li, Shixun Lin, Xuanlong Ma · 2024

Let G be a finite group with the identity element e. The proper order graph of G, denoted by â* (G), is an undirected graph with a vertex set G \ {e}, where two distinct vertices x and y are adjacent whenever o(x) | o(y) or o(y) | o(x), …

Finite groups whose coprime graphs are AT-free Open

Huani Li, Xuanlong Ma · 2024

Assume that $ G $ is a finite group. The coprime graph of $ G $, denoted by $ \Gamma(G) $, is an undirected graph whose vertex set is $ G $ and two distinct vertices $ x $ and $ y $ of $ \Gamma(G) $ are adjacent if and only if $ (o(x), o(y…

Perfect codes in 2-valent Cayley digraphs on abelian groups Open

Shilong Yu, Yuefeng Yang, Yushuang Fan, Xuanlong Ma · 2023

For a digraph $Γ$, a subset $C$ of $V(Γ)$ is a perfect code if $C$ is a dominating set such that every vertex of $Γ$ is dominated by exactly one vertex in $C$. In this paper, we classify strongly connected 2-valent Cayley digraphs on abeli…

Aspects of the commuting graph Open

Xuanlong Ma, Peter J‎. Cameron, Н. В. Маслова · 2023

The commuting graph of a group $G$ is the graph whose vertices are the elements of $G$, two distinct vertices joined if they commute. Our purpose in this paper is twofold: we discuss the computational problem of deciding whether a given gr…

Tropical leaf phenology characterization by using an ecologically-constrained deep learning model with PlanetScope satellites Open

Guangqin Song, Jing Wang, Michael J. Liddell, Leonor Patrícia Cerdeira Morellato, Calvin K. F. Lee , et al. · 2023

Tropical leaf phenology signals leaf-on/off status and exhibits strong variability from individual tree crowns to forest ecosystems, which importantly regulates carbon and water fluxes. The availability of daily PlanetScope data with high …

Divergent phenology response to nitrogen addition between a Mediterranean and a boreal forest Open

Yunpeng Luo, Petra D’Odorico, Sung‐Ching Lee, Xuanlong Ma, Mirco Migglivacca , et al. · 2023

Anthropogenic nitrogen (N) deposition and fertilization in the past decades shifted the ecosystem stoichiometry with potentially profound impacts on vegetation activity and ecosystem functioning. Current N-addition experiments mostly focus…

A Novel Inversion Approach for the Kernel-Driven BRDF Model for Heterogeneous Pixels Open

Hanliang Li, Kai Yan, Si Gao, Xuanlong Ma, Yelu Zeng , et al. · 2023

The bidirectional reflectance distribution function (BRDF) of the land surface contains information relating to its physical structure and composition. Accurate BRDF modeling for heterogeneous pixels is important for global ecosystem monit…

Finite Groups Whose Co-prime Order Graphs Have Positive Genus Open

Huani Li, Guo Zhong, Xuanlong Ma · 2022

Given a finite group G, the co-prime order graph of G is the simple undirected graph whose vertex set is G, and two distinct vertices x; y are adjacent if gcd(o(x); o(y)) = 1 or p, where p is a prime, and o(x) and o(y) are the orders of x …

Perfect codes in quintic Cayley graphs on abelian groups Open

Yuefeng Yang, Xuanlong Ma, Zeng Qing · 2022

A subset $C$ of the vertex set of a graph $Γ$ is called a perfect code of $Γ$ if every vertex of $Γ$ is at distance no more than one to exactly one vertex in $C$. In this paper, we classify all connected quintic Cayley graphs on abelian gr…

Certain properties of the enhanced power graph associated with a finite group Open

Parveen, Jitender Kumar, Siddharth Singh, Xuanlong Ma · 2022

The enhanced power graph of a finite group $G$, denoted by $\mathcal{P}_E(G)$, is the simple undirected graph whose vertex set is $G$ and two distinct vertices $x, y$ are adjacent if $x, y \in \langle z \rangle$ for some $z \in G$. In this…

Notes on the Co-prime Order Graph of a Group Open

Shangjing Hao, Guo Zhong, Xuanlong Ma · 2022

The co-prime order graph of a group $$G$$ is the graph with vertex set $$G$$, and two distinct elements $$x,y\in G$$ are adjacent if gcd$$(o(x),o(y))$$ is either $$1$$ or a prime, where $$o(x)$$ and $$o(y)$$ are the orders of $$x$$ and $$y…

A survey on enhanced power graphs of finite groups Open

Xuanlong Ma, Andrei Kelarev, Yuqing Lin, Kaishun Wang · 2022

We survey known results on enhanced power graphs of finite groups. Open problems, questions and suggestions for future work are also included.

Perfect Codes in Cayley Sum Graphs Open

Xuanlong Ma, Kaishun Wang, Yuefeng Yang · 2022

A subset $C$ of the vertex set of a graph $\Gamma$ is called a perfect code of $\Gamma$ if every vertex of $\Gamma$ is at distance no more than one to exactly one vertex in $C$. Let $A$ be a finite abelian group and $T$ a square-free subse…

Notes on the diameter of the complement of the power graph of a finite group Open

Xuanlong Ma, Alireza Doostabadi, Kaishun Wang · 2021

We determine the diameter of every connected component of the complement of the power graph and the enhanced power graph of a finite group, which completely answers two questions by Peter J. Cameron.

On the Metric Dimension of the Reduced Power Graph of a Finite Group Open

Xuanlong Ma, Lan Li · 2021

Let $G$ be a finite group. The reduced power graph of $G$ is the undirected graph whose vertex set is $G$, and two distinct vertices $x$ and $y$ are adjacent if $\langle x \rangle \subset \langle y \rangle$ or $\langle y \rangle \subset \l…

Про підгрупи Фішера скінченних груп Open

Yu Mao, Xuanlong Ma, Н. Т. Воробьев, T. B. Karaulova · 2021

УДК 512.542 Нехай – множина Фіттінга групи – деяка непорожня множина простих чисел і називається - множиною Фішера якщо з того, що і є -підгрупою для деякого завжди випливає Підгрупа групи називається -підгрупою Фішера як…

Forbidden subgraphs in enhanced power graphs of finite groups Open

Xuanlong Ma, Yubo Lv, Yanhong She · 2021

The enhanced power graph of a group is the simple graph whose vertex set is consisted of all elements of the group, and whose any pair of vertices are adjacent if they generate a cyclic subgroup. In this paper, we classify all finite group…

Completeness-resolvable graphs Open

Min Feng, Xuanlong Ma, Huiling Xu · 2021

Given a connected graph $G=(V(G), E(G))$, the length of a shortest path from a vertex $u$ to a vertex $v$ is denoted by $d(u,v)$. For a proper subset $W$ of $V(G)$, let $m(W)$ be the maximum value of $d(u,v)$ as $u$ ranging over $W$ and $v…

Finite groups whose intersection power graphs are toroidal and projective-planar Open

Huani Li, Xuanlong Ma, Ruiqin Fu · 2021

The intersection power graph of a finite group G G is the graph whose vertex set is G G , and two distinct vertices x x and y y are adjacent if either one of x x and y y is the identity element of G G , or ⟨ x ⟩ ∩ ⟨ y …

The intersection power graph associated with a finite group Open

Wei Lv, Xuanlong Ma · 2021

We characterize the independence number of the intersection power graph of a group, which extends some results in Aprose et al [Punjab Univ J Math 52 (2020):47-53].Moreover, the finite groups with dominatable intersection power graphs are …

Forbidden subgraphs in reduced power graphs of finite groups Open

Huani Li, Ruiqin Fu, Xuanlong Ma · 2021

Let G be a finite group. The reduced power graph of G is the undirected graph whose vertex set consists of all elements of G, and two distinct vertices x and y are adjacent if either ⟨x⟩⊂⟨y⟩ or ⟨y⟩⊂⟨x⟩. In this paper, we show that the redu…

The co-prime order graph associated with a finite group Open

Xuanlong Ma, Zhong-Hua Wang · 2020

Let $G$ be a finite group. The co-prime order graph of $G$ is the graph whose vertex set is $G$, and two distinct vertices $x,y$ are adjacent if gcd$(o(x),o(y))$ is either $1$ or a prime, where $o(x)$ and $o(y)$ are the orders of $x$ and $…

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