https://www.uav.ro/jour/index.php/tamcs/issue/feed 2025-06-11T14:44:10+03:00 Sorin Nadaban sorin.nadaban@uav.ro Open Journal Systems <p>The journal <strong>Theory and Applications of Mathematics &amp; Computer Science </strong>focuses on Applied Mathematics &amp; Computation. It publishes, free of charge, original papers of high scientific value in all areas of applied mathematics and computer science, but giving a preference to those in the areas represented by the editorial board. In addition, the improved analysis, including the effectiveness and applicability, of existing methods and algorithms, is of importance.</p> <p style="font-weight: 400;"><strong>Call for Papers</strong> - <strong>Special Issue in Memory of Professor Emeritus <em>Mihail Megan</em></strong></p> <p style="font-weight: 400;">We are pleased to announce a Call for Papers for a special issue of our journal <em><strong>Theory and Applications of Mathematics and Computer Science</strong></em><em>,</em><strong> </strong>dedicated to the memory of <strong>Professor Emeritus <em>Mihail Megan</em></strong>. Professor Mihail Megan was a distinguished scholar in the fields of Mathematical Analysis and Applications of Control Theory, whose work significantly shaped contemporary debates and inspired generations of researchers, colleagues, and students.</p> <p style="font-weight: 400;">This special issue aims to honor Professor Mihail Megan’s remarkable legacy by bringing together original research, critical reflections, and tributes that engage with the themes central to their scholarly contributions. We invite submissions that reflect the breadth and depth of their impact, including—but not limited to—topics such as:</p> <ul> <li>Qualitative Theory of Infinite Dimensional Dynamical Systems</li> <li>Control Theory</li> <li>Reflections on Professor Mihail Megan’s influence in the domain of Mathematical Analysis</li> <li>Archival insights, interviews, or unpublished materials related to his work</li> </ul> <p style="font-weight: 400;">We welcome contributions from scholars at all stages of their careers. In addition to full-length articles, we also invite shorter reflections or personal tributes (1,000–2,000 words) that speak of Professor Mihail Megan’s mentorship, collaboration, or intellectual legacy.</p> <p style="font-weight: 400;"><strong>Submission Guidelines</strong></p> <p style="font-weight: 400;">Please submit your manuscript through the submission system of the journal <em>Theory and Applications of Mathematics and Computer Science</em> by <strong>November 15th, 2025</strong>. All submissions will be peer-reviewed in accordance with the journal’s standard procedures. Authors should follow the journal’s submission guidelines.</p> <p style="font-weight: 400;">For further inquiries, please contact <strong>codruta.stoica@uav.ro</strong>.</p> <p style="font-weight: 400;">We look forward to receiving your contributions and joining together in this collective tribute to a scholar whose work continues to resonate across disciplines.</p> https://www.uav.ro/jour/index.php/tamcs/article/view/2256 2025-02-17T16:05:57+02:00 Claudia Luminita Mihit claudia.mihit@uav.ro

<p>In this paper we approach concepts of nonuniform dichotomy for the case of discrete skew-product semiflows. Di erent<br>characterizations of this properties are given from the point of view of invariant and strongly invariant projector families.</p>

2025-06-11T00:00:00+03:00 Copyright (c) 2025 Theory and Applications of Mathematics and Computer Science https://www.uav.ro/jour/index.php/tamcs/article/view/2257 2025-02-17T16:06:59+02:00 Rovana Boruga Toma rovanaboruga@gmail.com

<p>In the present paper we deal with the concept of polynomial stability in average. We obtain two characterization theorems<br>that describe the concept mentioned above. In fact, we give a logarithmic criterion and a Datko type theorem for cocycles of linear<br>operators.</p>

2025-06-11T00:00:00+03:00 Copyright (c) 2025 Theory and Applications of Mathematics and Computer Science https://www.uav.ro/jour/index.php/tamcs/article/view/2258 2025-02-17T16:08:59+02:00 Arjuna P.H. Don pilippua@myumanitoba.ca James F. Peters James.Peters3@umanitoba.ca

<p>This article introduces an application of Ghrist barcodes in the study of persistent Betti numbers derived from vortex nerve<br>complexes found in triangulations of video frames. A Ghrist barcode (also called a persistence barcode) is a topology of data pictograph<br>useful in representing the persistence of the features of changing shapes. The basic approach is to introduce a free Abelian<br>group representation of intersecting filled polygons on the barycenters of the triangles of Alexandroff nerves. An Alexandroff nerve<br>is a maximal collection of triangles of a common vertex in the triangulation of a finite, bounded planar region. In our case, the<br>planar region is a video frame. A Betti number is a count of the number of generators is a finite Abelian group. The focus here<br>is on the persistent Betti numbers across sequences of triangulated video frames. Each Betti number is mapped to an entry in a<br>Ghrist barcode. Two main results are given, namely, vortex nerves are Edelsbrunner-Harer nerve complexes and the Betti number<br>of a vortex nerve equals k + 2 for a vortex nerve containing k edges attached between a pair of vortex cycles in the nerve.</p>

2025-06-11T00:00:00+03:00 Copyright (c) 2025 Theory and Applications of Mathematics and Computer Science