East West Math http://eastwestmath.org/index.php/ewm en-US nhbtrung@ntt.edu.vn (Trung, Nguyen Hoang Bao) Tue, 12 May 2026 11:58:25 +0800 OJS 3.1.2.1 http://blogs.law.harvard.edu/tech/rss 60 SEMIGROUP OF 2 × 2 TROPICAL CIRCULANT MATRICES AND THE BIORDER STRUCTURE OF THEIR IDEMPOTENTS http://eastwestmath.org/index.php/ewm/article/view/534 <p><span class="fontstyle0">Tropical circulant matrix is a circulant matrix which operates within the tropical algebra framework where addition is replaced by the minimum and multiplication by the ordinary addition. These matrices have found applications in areas like cryptography and graph theory. In this paper we are dealing with </span><span class="fontstyle2">C</span><span class="fontstyle3">2</span><span class="fontstyle0">(</span><span class="fontstyle4">R</span><span class="fontstyle0">), the multiplicative semigroup of 2 </span><span class="fontstyle5">× </span><span class="fontstyle0">2 circulant matrices over tropical semiring </span><span class="fontstyle4">R </span><span class="fontstyle0">= (</span><span class="fontstyle4">R </span><span class="fontstyle5">[ f1g</span><span class="fontstyle2">; </span><span class="fontstyle0">min</span><span class="fontstyle2">; </span><span class="fontstyle0">+). The semigroup </span><span class="fontstyle2">M</span><span class="fontstyle3">2</span><span class="fontstyle0">(</span><span class="fontstyle4">R</span><span class="fontstyle0">) of all 2</span><span class="fontstyle5">×</span><span class="fontstyle0">2 tropical matrices are known to be a regular semigroup. We show that the subsemigroup </span><span class="fontstyle2">C</span><span class="fontstyle3">2</span><span class="fontstyle0">(</span><span class="fontstyle4">R</span><span class="fontstyle0">) of circulant matrices is an inverse semigroup, that is, a regular semigroup in which every element has a unique inverse. It is known that the set of idempotents of an inverse semigroup is a semi-lattice and this semi-lattice of idempotents provides a way to understand and analyze the structure and behavior of inverse semigroups. So the semi-lattice </span><span class="fontstyle2">E</span><span class="fontstyle0">(</span><span class="fontstyle2">C</span><span class="fontstyle3">2</span><span class="fontstyle0">) of idempotents of </span><span class="fontstyle2">C</span><span class="fontstyle3">2</span><span class="fontstyle0">(</span><span class="fontstyle4">R</span><span class="fontstyle0">) plays a crucial role in the structure of </span><span class="fontstyle2">C</span><span class="fontstyle3">2</span><span class="fontstyle0">(</span><span class="fontstyle4">R</span><span class="fontstyle0">). Also we determine the biorder structure of the set of idempotents and describe the sandwich sets associated with the idempotents. A description of the associated inductive groupoid is also given.</span> </p> Ardra T. Joy, Prakash G. N. Shenoi, A. R. Rajan Copyright (c) 2026 East West Math http://eastwestmath.org/index.php/ewm/article/view/534 Tue, 12 May 2026 11:36:46 +0800 CATEGORY OF PRESHEAVES OF A LIE GROUPOID AND REPRESENTATION OF LIE GROUPOIDS http://eastwestmath.org/index.php/ewm/article/view/535 <p><span class="fontstyle0">A representation of a Lie groupoid </span><span class="fontstyle2">G </span><span class="fontstyle0">:= </span><span class="fontstyle3">G </span><span class="fontstyle4">⇒ </span><span class="fontstyle3">M </span><span class="fontstyle0">is a Lie groupoid </span><span class="fontstyle0">morphism of </span><span class="fontstyle2">G </span><span class="fontstyle0">to a Lie groupoid of manifolds. In this article, we provide a representation of a Lie groupoid </span><span class="fontstyle2">G </span><span class="fontstyle0">via the functor category of presheaves of </span><span class="fontstyle2">G </span><span class="fontstyle0">and their equivalence to </span><span class="fontstyle3">Man</span><span class="fontstyle5">G</span><span class="fontstyle0">, the Lie groupoid of right </span><span class="fontstyle2">G</span><span class="fontstyle0">-manifolds and right </span><span class="fontstyle2">G</span><span class="fontstyle0">-manifold morphisms.</span> </p> P. G. Romeo Copyright (c) 2026 East West Math http://eastwestmath.org/index.php/ewm/article/view/535 Tue, 12 May 2026 11:41:16 +0800 RELATIONS BETWEEN THE INDEPENDENCE POLYNOMIAL OF STAR GRAPHS AND THEIR ASSOCIATED JULIA SETS http://eastwestmath.org/index.php/ewm/article/view/536 <p><span class="fontstyle0">Independence polynomials of star graphs are used to investigate their dynamic behavior. The analysis covers structural aspects, examines polynomial stability, and studies the symmetry and rotational attributes of the corresponding Julia sets. The results offer insight into the interaction between graph theory and complex dynamics.</span> </p> K U Sreeja Copyright (c) 2026 East West Math http://eastwestmath.org/index.php/ewm/article/view/536 Tue, 12 May 2026 11:49:11 +0800 AN ALGORITHM FOR DETERMINING LIE ALGEBRA TYPES http://eastwestmath.org/index.php/ewm/article/view/537 <p><span class="fontstyle0">This paper investigates the Jordan{Kronecker invariant of finite dimensional complex Lie algebras. We present an explicit algorithm for determining the type of a given Lie algebra from its Jordan{Kronecker invariant. The algorithm is implemented in a specific Matlab program.</span> </p> Tu T. C. Nguyen, Tuan A. Nguyen, Vu A. Le Copyright (c) 2026 East West Math http://eastwestmath.org/index.php/ewm/article/view/537 Tue, 12 May 2026 00:00:00 +0800 MODELING CHEATING BEHAVIOR IN ONLINE EXAMS: A THEORY OF PLANNED BEHAVIOR (TPB) BASED APPROACH http://eastwestmath.org/index.php/ewm/article/view/538 <p><span class="fontstyle0">Cheating in higher education has been widely studied, yet findings on its prevalence across traditional and online learning environments remain inconsistent. The COVID-19 pandemic triggered a sudden global shift to online education and examinations, amplifying concerns over academic integrity. Empirical evidence from this period suggests a surge in cheating behaviors; however, most studies lacked a robust theoretical framework to explain this trend. This paper develops and validates a theoretical model of online cheating, grounded in Ajzen’s Theory of Planned Behavior (TPB) and enhanced by Bandura’s concept of moral disengagement. To capture the unique dynamics of online exams, we refine the traditional TPB construct of Perceived Behavioral Control into two distinct dimensions: Regulations (REG), encompassing institutional policies and monitoring technologies, and Enabling Technology (TEC), referring to digital tools and platforms that facilitate misconduct. Using Structural Equation Modeling (SEM) with survey data from students at three Vietnamese universities in 2022, our findings confirm the model’s explanatory power in identifying factors that contributed to the surge of online cheating during the pandemic-driven transition. <br></span></p> Duong Quang Hoa, Ha Van Hieu, Do Ba Khang, Do Ba Khang Copyright (c) 2026 East West Math http://eastwestmath.org/index.php/ewm/article/view/538 Tue, 12 May 2026 11:58:06 +0800 POSITIVE WEAK SOLUTIONS OF THE STEKLOV PROBLEM FOR A CLASS OF QUASI LINEAR ELLIPTIC OPERATORS CONTAINING THE p(·)- LAPLACIAN AND THE MEAN CURVATURE OPERATOR http://eastwestmath.org/index.php/ewm/article/view/539 <p><span class="fontstyle0">In this paper, we consider the existence of positive weak solutions for a class of quasilinear elliptic operators containing </span><span class="fontstyle2">p</span><span class="fontstyle0">(</span><span class="fontstyle3">·</span><span class="fontstyle0">)-Laplacian and mean curvature operator with the Steklov boundary condition. The results for </span><span class="fontstyle2">p</span><span class="fontstyle0">(</span><span class="fontstyle3">·</span><span class="fontstyle0">)-Laplacian are known, however, we attempt in this paper to extend the results for a class of quasilinear elliptic operators containing not only </span><span class="fontstyle2">p</span><span class="fontstyle0">(</span><span class="fontstyle3">·</span><span class="fontstyle0">)-Laplacian but also the mean curvature operator.</span> </p> Junichi Aramaki Copyright (c) 2026 East West Math http://eastwestmath.org/index.php/ewm/article/view/539 Tue, 12 May 2026 12:05:55 +0800