323 results
Search Results
2. On the paper “Regular equivalence relations on ordered ∗-semihypergroups”.
- Author
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KEHAYOPULU, Niovi
- Subjects
- *
TURKS , *CONGRUENCE lattices , *MATHEMATICS - Abstract
If (S, ◦,≤) is an ordered hypersemigroup, an equivalence relation ρ on S is called congruence if (a, b) ∈ ρ implies (a ◦ x, b ◦ x) ∈ ρ and (x ◦ a, x ◦ b) ∈ ρ for every x ∈ S ; in the sense that for every u ∈ a ◦ x there exists v ∈ b ◦ x such that (u, v) ∈ ρ and for every u ∈ x◦a there exists v ∈ x◦b such that (u, v) ∈ ρ. It has been proved in Turk J Math 2021(5) [On the paper “A study on (strong) order-congruences in ordered semihypergroups”] that if S is an ordered hypersemigroup, then there exists a congruence ρ on S such that S/ρ is an ordered hypersemigroup. This result, is the main result for an involution ordered hypersemigroup by Xinyang Feng, Jian Tang and Yanfeng Luo in U.P.B. Sci. Bull, Series A, 2018, but its proof is wrong; the correct proof is given in the present paper. Examples illustrate the results. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
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3. On the paper "Generalized hyperideals in locally associative left almost semihypergroups".
- Author
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KEHAYOPULU, Niovi
- Subjects
- *
MULTIPLICATION , *MATHEMATICS , *DEFINITIONS - Abstract
This note is written to show that the definition of the LA-semihypergroup by V. Amjad, K. Hila and F. Yousafzai "Generalized hyperideals in locally associative left almost semihypergroups, New York J. Math. 2014" should be corrected and that it is not enough to replace the multiplication "·" of an LA-semigroup by the hyperoperation "ο" to pass from an LA-semigroup to an LA-semihypergroup. The two examples of the paper based on the definition of the LA-semihypergroup are wrong that is a further indication that this definition needs correction. According to the last section of the paper, the paper generalizes the results of an LA-semigroup by M. Akram, N. Yaqoob and M. Khan "On (m, n) -ideals of left almost semigroups, Appl. Math. Sci. (Ruse) 2013" while the paper duplicates, without citation, the section 4 of the paper by W. Khan, F. Yousafzai, W. Guo and M. Khan "On (m, n) -ideals of left almost semigroups, J. Semigroup Theory Appl. 2014" with the usual change of "·" to "ο". [ABSTRACT FROM AUTHOR]
- Published
- 2022
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4. Erratum to the paper "Fifty Years of Kurepa's !n Hypothesis" by Žarko Mijajlović.
- Author
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Smarandache, Florentin
- Subjects
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HYPOTHESIS , *MATHEMATICS - Abstract
In this short note we prove that the Kurepa (K) function is different from the Smarandache-Kurepa (SK) function, therefore, these functions are not the same, as Mijajlović has unfoundedly accused the prestigious Encyclopedia of Mathematics and this author. This note is an answer to Mijajlović's paper (Žarko Mijajlović, Fifty years of Kurepa's !n hypothesis, Bulletin T.CLIV de l'Académie serbe des sciences et des arts - 2021 Classe des Sciences mathématiques et naturelles Sciences mathématiques, No. 46, 169-181 (2021). [ABSTRACT FROM AUTHOR]
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- 2021
- Full Text
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5. Novel Feature-Based Difficulty Prediction Method for Mathematics Items Using XGBoost-Based SHAP Model.
- Author
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Yi, Xifan, Sun, Jianing, and Wu, Xiaopeng
- Subjects
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MACHINE learning , *UNIQUENESS (Mathematics) , *COLLEGE entrance examinations , *EDUCATIONAL standards , *MATHEMATICS examinations, questions, etc. , *MATHEMATICS - Abstract
The level of difficulty of mathematical test items is a critical aspect for evaluating test quality and educational outcomes. Accurately predicting item difficulty during test creation is thus significantly important for producing effective test papers. This study used more than ten years of content and score data from China's Henan Provincial College Entrance Examination in Mathematics as an evaluation criterion for test difficulty, and all data were obtained from the Henan Provincial Department of Education. Based on the framework established by the National Center for Education Statistics (NCES) for test item assessment methodology, this paper proposes a new framework containing eight features considering the uniqueness of mathematics. Next, this paper proposes an XGBoost-based SHAP model for analyzing the difficulty of mathematics tests. By coupling the XGBoost method with the SHAP method, the model not only evaluates the difficulty of mathematics tests but also analyzes the contribution of specific features to item difficulty, thereby increasing transparency and mitigating the "black box" nature of machine learning models. The model has a high prediction accuracy of 0.99 for the training set and 0.806 for the test set. With the model, we found that parameter-level features and reasoning-level features are significant factors influencing the difficulty of subjective items in the exam. In addition, we divided senior secondary mathematics knowledge into nine units based on Chinese curriculum standards and found significant differences in the distribution of the eight features across these different knowledge units, which can help teachers place different emphasis on different units during the teaching process. In summary, our proposed approach significantly improves the accuracy of item difficulty prediction, which is crucial for intelligent educational applications such as knowledge tracking, automatic test item generation, and intelligent paper generation. These results provide tools that are better aligned with and responsive to students' learning needs, thus effectively informing educational practice. [ABSTRACT FROM AUTHOR]
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- 2024
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6. Correction: Almalaq et al. Deep Machine Learning Model-Based Cyber-Attacks Detection in Smart Power Systems. Mathematics 2022, 10 , 2574.
- Author
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Almalaq, Abdulaziz, Albadran, Saleh, and Mohamed, Mohamed A.
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DEEP learning , *MACHINE learning , *DECISION trees , *ARTIFICIAL neural networks , *MATHEMATICS , *INFORMATION technology , *SMART power grids - Abstract
This correction notice provides updates and corrections to a research paper on deep machine learning model-based cyber-attacks detection in smart power systems. The paper proposes a deep learning-based attack detection model that addresses system disturbances caused by natural events and cyber-attacks. It discusses the use of principal component analysis (PCA) for feature selection and the potential of deep learning-based and decision tree classifiers for detecting cyber-attacks in intelligent energy grids. The notice also includes updates to references, clarifications on the experimental data set, and feature selection based on PCA. The study evaluates the effectiveness of the proposed model using various assessment indexes and compares it to conventional methods, concluding that the proposed model is effective in detecting cyber-attacks and demonstrates good performance in detecting destructive attacks. [Extracted from the article]
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- 2024
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7. Theory and every thing: acquiring the office of Professor Stephen Hawking as a resource for history and museology.
- Author
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Blyth, Tilly and Boyle, Alison
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SCIENCE museums , *MUSEUM studies , *MUSEUM acquisitions , *SCIENTIFIC knowledge , *COMPLEXITY (Philosophy) , *COMMERCIAL art galleries - Abstract
How do the curators of science and technology collections represent the daily realities of doing science? Through the acquisition of Professor Stephen Hawking's office by the Science Museum, this paper will explore what is involved in making major acquisitions for national collections. How do curators consider what to preserve from the eclectic range of items found in the working spaces of scientists? What do the personal artefacts of a scientist's life represent, and what do acts of curatorial choices say about the narratives that are foregrounded -- and those that are not -- in positioning that life historically? And how do those choices illuminate the considerations involved in the way science and technology is represented in our national collections? By going beyond the glass case, we consider what it takes to bring an object into a collection: the intellectual considerations of how its stories are preserved for a nation and the practical considerations required so that items can even be considered for future display. The paper illuminates the formal and informal networks around scientists' collections, and the processes and judgements that science and technology curators make every day when choosing what could be important for defining our history. Using the Stephen Hawking office as a case study the article explores the representation of scientific practice in museum collections, the relationship of some collections with celebrity and disability, and some of the challenges posed by science and technology acquisitions compared to other types of museum object. The paper explores how knowledge is generated in museum collections, through the act of acquiring a new collection. It asks fundamental questions, which are essential to the fields of museology and science and technology studies, about the contribution to knowledge made by personal scientific objects. It goes beyond the study of collections as artefacts of display in exhibitions and galleries, providing a detailed analysis of a routine but oftenneglected aspect of behind-the-scenes museum work: the acquisition of a collection. Arguing that a large and complex collection is a vital tool for understanding the complexity of science, the paper uses the 'museum as method' (Thomas, 2016) which prioritises simple curatorial questions and the use of the objects in exploration; this enables scholars and curators to respond to material evidence of scientific knowledge, and identify narratives that are prioritised, and others that are obscured, in the historic record. In doing so, it suggests that curators are uniquely placed to provide insights into the roles of human and non-human actors in the construction of scientific knowledge, demonstrating how the Hawking collection allows us to explore the nature of scientific practice, the creation of scientific celebrity, and the potential to give visibility to disability within the history of science whilst de-centring the myth of the scientific genius in museum narratives. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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8. On input and Langlands parameters for epipelagic representations.
- Author
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Romano, Beth
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L-functions , *MATHEMATICS - Abstract
A paper of Reeder–Yu [J. Amer. Math. Soc. 27 (2014), pp. 437–477] gives a construction of epipelagic supercuspidal representations of p-adic groups. The input for this construction is a pair (\lambda, \chi) where \lambda is a stable vector in a certain representation coming from a Moy–Prasad filtration, and \chi is a character of the additive group of the residue field. We say two such pairs are equivalent if the resulting supercuspidal representations are isomorphic. In this paper we describe the equivalence classes of such pairs. As an application, we give a classification of the simple supercuspidal representations for split adjoint groups. Finally, under an assumption about unramified base change, we describe properties of the Langlands parameters associated to these simple supercuspidals, showing that they have trivial L-functions and minimal Swan conductors, and showing that each of these simple supercuspidals lies in a singleton L-packet. [ABSTRACT FROM AUTHOR]
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- 2024
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9. Discussion of "A general theory for anisotropic Kirchhoff-Love shells with in-plane bending of embedded fibers," by T.X Duong, et al., Math. Mech. Solids 28, 1274–1317 (2023).
- Author
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Steigmann, David J
- Subjects
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MATHEMATICS , *HONEY , *FIBERS , *ELASTIC plates & shells , *LAGRANGE multiplier , *GALILEAN relativity - Abstract
The document titled "Discussion of 'A general theory for anisotropic Kirchhoff-Love shells with in-plane bending of embedded fibers'" is a critique of a paper that contains misleading and incorrect statements. The objections mainly focus on two remarks made in the paper. The document argues that the symmetrization employed in a previous work is valid for all cases, contrary to what the paper suggests. It also disputes the claim that a theory fails to properly account for the energetic effect of a change in geodesic curvature. The document provides counterarguments and references to support its claims. The author of the document is David J Steigmann. [Extracted from the article]
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- 2024
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10. Common best proximity point theorems in Hausdorff topological spaces.
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Sreelakshmi Unni, A. and Pragadeeswarar, V.
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HAUSDORFF spaces , *MATHEMATICS , *TOPOLOGICAL spaces - Abstract
In the present paper, we have obtained common best proximity point theorems of nonself maps in Hausdorff topological space. Further, our results extend the results due to Gerald F. Jungck, thereby proving a generalized version of Kirk's theorem (J. London Math. 1(1):107–111, 1969). [ABSTRACT FROM AUTHOR]
- Published
- 2024
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11. Enhanced Turan-type Inequalities for Polynomials.
- Author
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N., Reingachan, Soraisam, Robinson, Devi, Khangembam Babina, Singh, M. Singhajit, and Chanam, Barchand
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POLYNOMIALS , *MATHEMATICS , *BULLS - Abstract
If p(z) = Xn ν=0 aνz ν is a polynomial of degree n having all its zeros in |z| ≤ k, k ≥ 1, Jain [Bull. Math. Soc. Sci. Math. Roumania Tome, 59(2016), 339-347] proved max |z|=1 |p′ (z)| ≥ nAk max |z|=1 |p(z)|, where Ak = ( |a0| + |an|k n+1/ |ao|(1 + k n+1) + |an|(k n+1 + k 2n) ) . In this paper, we initially derive a generalized form that not only encompasses but also enhances the aforementioned inequality. Additionally, we extend this formulation to a more comprehensive result, thereby producing an improved outcome for certain established inequalities as a specific instance. [ABSTRACT FROM AUTHOR]
- Published
- 2024
12. A literature review: Mathematics vocabulary intervention for students with mathematics difficulty.
- Author
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Lariviere, Danielle O., Arsenault, Tessa L., and Payne, S. Blair
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LITERATURE reviews , *MATHEMATICS students , *INTEGERS , *VOCABULARY , *LANGUAGE acquisition , *MATHEMATICS - Abstract
This paper details a literature review of mathematics vocabulary intervention studies for students with mathematics difficulty. The primary aim was to identify instructional practices that support mathematics vocabulary development. We conducted a database search to identify mathematics intervention studies either focused exclusively on vocabulary or with an embedded vocabulary component. Ultimately, 13 studies with participants from kindergarten to Grade 8 were included in the review. The majority of included studies had dual foci on vocabulary and other mathematics content, including whole number computation, word problem solving, fractions, algebra, or geometry. All studies that measured mathematics vocabulary performance indicated positive student outcomes. In addition, multiple studies indicated positive effects on measures of other mathematics content beyond mathematics vocabulary knowledge. We noted six instructional practices across studies that bolstered the mathematics vocabulary performance of students with mathematics difficulty. From most to least common, these practices included formal vocabulary use, explicit instruction, use of representations, repeated exposures, pre‐teaching, and graphic organizers. Implications are addressed for both researchers and practitioners. [ABSTRACT FROM AUTHOR]
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- 2024
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13. EMOTIONAL HABITUAL SUBJECTIVE WELL-BEING IN SELECTED LESSONS AMONG SECONDARY SCHOOL STUDENTS.
- Author
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ŠKORVAGOVÁ, EVA and BARNIŠINOVÁ, MAGDALÉNA
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STUDENT attitudes , *SECONDARY school students , *SUBJECTIVE well-being (Psychology) , *MATHEMATICS education , *CIVICS education , *MATHEMATICS - Abstract
The paper focuses on finding the relationships between the frequency of experiencing positive and negative emotional states, students' subjective evaluation of the subjects of mathematics, Slovak language and literature, English language, civics and physical education in terms of their popularity, difficulty and importance, and school achievement in these subjects. The research population consisted of 168 (100%) pupils second and third-year pupils of a secondary vocational school in Žilina. The research included: the Subjective Emotional Habitual Well-being Questionnaire (Džuka, Dalbert, 2002) and the Attitudes to Learning Subjects Questionnaire for Pupils (Hrabal, Pavelková, 2010). The most important results of the research revealed that the teaching subject of mathematics was rated the worst in all the surveyed items. Pupils perceived mathematics as the least favourite subject, the most challenging, the least important. They had the worst average school achievement in it, experienced the most negative and least frequently positive emotional state of all the subjects studied. English was the most significant teaching subject. Physical education was the most popular subject taught to the students. Pupils' attitudes towards the subjects taught did not change much over time, being stable and unambiguous. Only the subject of mathematics, which current pupils perceived to be less popular and less important than in the past, showed a change. We found a high correlation between the frequency of experiencing a positive state of mind and the popularity of the assessed teaching subjects in mathematics and physical education. [ABSTRACT FROM AUTHOR]
- Published
- 2024
14. A New Class of Coordinated Non-Convex Fuzzy-Number-Valued Mappings with Related Inequalities and Their Applications.
- Author
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Rakhmangulov, Aleksandr, Aljohani, A. F., Mubaraki, Ali, and Althobaiti, Saad
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INTEGRAL inequalities , *APPLIED mathematics , *GENERALIZED integrals , *NUMERICAL integration , *INTEGRALS , *MATHEMATICS - Abstract
Both theoretical and applied mathematics depend heavily on integral inequalities with generalized convexity. Because of its many applications, the theory of integral inequalities is currently one of the areas of mathematics that is evolving at the fastest pace. In this paper, based on fuzzy Aumann's integral theory, the Hermite–Hadamard's type inequalities are introduced for a newly defined class of nonconvex functions, which is known as U · D preinvex fuzzy number-valued mappings ( U · D preinvex F · N · V · M s) on coordinates. Some Pachpatte-type inequalities are also established for the product of two U · D preinvex F · N · V · M s, and some Hermite–Hadamard–Fejér-type inequalities are also acquired via fuzzy Aumann's integrals. Additionally, several new generalized inequalities are also obtained for the special situations of the parameters. Additionally, some of the interesting remarks are provided to acquire the classical and new exceptional cases that can be considered as applications of the main outcomes. Lastly, a few suggested uses for these inequalities in numerical integration are made. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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15. Correction to: Conormal Spaces and Whitney Stratifications.
- Author
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Helmer, Martin and Nanda, Vidit
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MATHEMATICS - Abstract
This note remedies an error in our paper tilted Conormal Spaces and Whitney Stratifications (Found. Comput. Math., 2022). [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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16. The mathematics and mechanics of tug of war.
- Author
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Moulton, Derek E and Oliveri, Hadrien
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STATIC equilibrium (Physics) , *MATHEMATICS , *MECHANICAL models , *WAR games , *DYNAMIC models - Abstract
In this paper, we propose a mechanical model for a game of tug of war (rope pulling). We focus on a game opposing two players, modelling each player's body as a structure composed of straight rods that can be actuated in three different ways to generate a pulling force. We first examine the static problem of two opponents being in a deadlock configuration of mechanical equilibrium; here we show that this situation is essentially governed by the ratio of masses of the players, with the heavier player having a strong advantage. We then turn to the dynamic problem and model the response of the system to an abrupt change in activation by one of the players. In this case, the system exhibits a nontrivial response; in particular, we compare a sudden pulling and a sudden "letting up," and demonstrate the existence of regimes in which the lighter player can momentarily take the advantage. [ABSTRACT FROM AUTHOR]
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- 2024
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17. Exploring q-Bernstein-Bézier surfaces in Minkowski space: Analysis, modeling, and applications.
- Author
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Bashir, Sadia, Ahmad, Daud, and Ali, Ghada
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MINKOWSKI space , *MICROSOFT Surface (Computer) , *COMPUTER graphics , *COMPUTER-aided design , *GEOMETRIC modeling , *GAUSSIAN curvature , *MATHEMATICS - Abstract
In this paper, we examine q-Bernstein-Bézier surfaces in Minkowski space- R13 with q as the shape parameter. These surfaces, a generalization of Bézier surfaces, have applications in mathematics, computer-aided geometric design, and computer graphics for the surface formation and modeling. We analyze the timelike and spacelike cases of q-Bernstein-Bézier surfaces using known boundary control points. The mean curvature and Gaussian curvature of these q-Bernstein-Bézier surfaces are computed by finding the respective fundamental coefficients. We also investigate the shape operator dependency for timelike and spacelike q-Bernstein-Bézier surfaces in Minkowski space- R13 , and provide biquadratic and bicubic q-Bernstein-Bézier surfaces as illustrative examples for different values of the shape controlling parameter q. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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18. A study on reversed dynamic inequalities of Hilbert-type on time scales nabla calculus.
- Author
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Saied, A. I.
- Subjects
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CALCULUS , *INTEGRAL inequalities , *MATHEMATICS - Abstract
In this paper, we establish some reversed dynamic inequalities of Hilbert type on time scales nabla calculus by applying reversed Hölder's inequality, chain rule on time scales, and the mean inequality. As particular cases of our results (when T = N and T = R ), we get the reversed form of discrete and continuous inequalities proved by Chang-Jian, Lian-Ying and Cheung (Math. Slovaca 61(1):15–28, 2011). [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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19. ChatGPT-generated help produces learning gains equivalent to human tutor-authored help on mathematics skills.
- Author
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Pardos, Zachary A. and Bhandari, Shreya
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CHATGPT , *LANGUAGE models , *QUALITY control , *MATHEMATICS - Abstract
Authoring of help content within educational technologies is labor intensive, requiring many iterations of content creation, refining, and proofreading. In this paper, we conduct an efficacy evaluation of ChatGPT-generated help using a 3 x 4 study design (N = 274) to compare the learning gains of ChatGPT to human tutor-authored help across four mathematics problem subject areas. Participants are randomly assigned to one of three hint conditions (control, human tutor, or ChatGPT) paired with one of four randomly assigned subject areas (Elementary Algebra, Intermediate Algebra, College Algebra, or Statistics). We find that only the ChatGPT condition produces statistically significant learning gains compared to a no-help control, with no statistically significant differences in gains or time-on-task observed between learners receiving ChatGPT vs human tutor help. Notably, ChatGPT-generated help failed quality checks on 32% of problems. This was, however, reducible to nearly 0% for algebra problems and 13% for statistics problems after applying self-consistency, a "hallucination" mitigation technique for Large Language Models. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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20. Undergraduate Mathematics Students Question and Critique Society Through Mathematical Modeling.
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Tidwell, Will and Bennett, Amy
- Subjects
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MATHEMATICS students , *UNDERGRADUATES , *MATHEMATICAL models , *MATHEMATICS , *STUDENT teachers , *SOCIAL justice - Abstract
Mathematics can be used as a tool to question and critique society and, in doing so, give us more information about the world around us and how it operates. This however, is not a common perspective that is conveyed to students during their undergraduate mathematics coursework. This paper contributes to the understanding of how undergraduate mathematics students question and critique society via mathematical modeling tasks. In two courses at two universities, 27 mathematics majors and secondary preservice teachers engaged in the modeling process situated in authentic contexts to learn specific concepts and make mathematical connections across domains and disciplines. Both courses culminated in a final project in which students created and investigated solutions to their own modeling tasks. In this paper, we describe how our courses (1) centered justice as pedagogy, (2) were environments for student agency and exploration, and (3) explicitly demonstrated how mathematics and social justice are intertwined. Drawing on frameworks of mathematical modeling for social justice, we present and analyze student-created tasks to showcase how they utilized mathematics as a tool to question and critique the world around them. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
21. On new approach to semi-Fredholm theory in unital C*-algebras.
- Author
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Ivković, Stefan
- Subjects
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HILBERT modules , *C*-algebras , *HILBERT transform , *MATHEMATICS - Abstract
Axiomatic Fredholm theory in unital C*-algebras was established in [D. Kečkić, Z. Lazović, Acta Sci. Math., 83(3-4):629-655, 2017]. Following the pure algebraic approach by Keckic and Lazovic, in the author’s paper [S. Ivkovic, Banach J. Math. Anal., 17:51, 2023] we extended further this theory to axiomatic semi-Fredholm and semi-Weyl theory in unital C*- algebras. However, recently, in [S. Ivković, arXiv:2306.01133] we developed another approach to axiomatic Fredholm theory in unital C*-algebras which is based on the theory of Hilbert modules and is equivalent to the algebraic approach by Kečkić and Lazović. In this paper, we extend further that new Hilbert-module approach from Fredholm theory to semi-Fredholm and semiWeyl theory in unital C*-algebras. Hence, we provide new proofs to the results in [S. Ivkovic, Banach J. Math. Anal., 17:51, 2023]. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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22. Roadmap of the Multiplier Method for Partial Differential Equations.
- Author
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Alvarez-Valdez, Juan Arturo and Fernandez-Anaya, Guillermo
- Subjects
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PARTIAL differential equations , *ABSTRACT algebra , *MATHEMATICAL physics , *GROUP theory , *NOETHER'S theorem - Abstract
This review paper gives an overview of the method of multipliers for partial differential equations (PDEs). This method has made possible a lot of solutions to PDEs that are of interest in many areas such as applied mathematics, mathematical physics, engineering, etc. Looking at the history of the method and synthesizing the newest developments, we hope to give it the attention that it deserves to help develop the vast amount of work still needed to understand it and make the best use of it. It is also an interesting and a relevant method in itself that could possibly give interesting results in areas of mathematics such as modern algebra, group theory, topology, etc. The paper will be structured in such a manner that the last review known for this method will be presented to understand the theoretical framework of the method and then later work done will be presented. The information of four recent papers further developing the method will be synthesized and presented in such a manner that anyone interested in learning this method will have the most relevant information available and have all details cited for checking. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
23. Harary index, binding number and toughness of graphs.
- Author
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Mingqiang An
- Subjects
- *
MATHEMATICS - Abstract
Given a connected (molecular) graph G, its Harary index H(G) is defined by the reciprocal sum of the distances between all unordered pairs of vertices of G. Lower bounds on the graph vulnerability parameters binding number and toughness have been often used to determine that the graph has a certain property. Recently, Yatauro [Discrete Appl. Math. 338 (2023) 56-68] gave a sharp upper bound of W (G) (Wiener index) to ensure that G has a determined lower bound (greater than or equal to 1) for the binding number or toughness. In this paper, we supply an upper bound on H(G) to ensure that G has a determined lower bound (between 0 and 1) for the binding number or toughness, and show that these bounds are best possible in some sense. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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24. On the uniqueness of a meromorphic function and its higher difference operator under the purview of two shared sets.
- Author
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Mallick, Sanjay and Basak, Pratap
- Subjects
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MEROMORPHIC functions , *DIFFERENCE operators , *MALAYS (Asian people) , *MATHEMATICS - Abstract
In the paper, we investigate the uniqueness problem of a meromorphic function and its difference operator to the most general setting via two shared set problems and thus improve a recent result of Chen–Chen (Bull Malays Math Sci Soc 35(3): 765-774, 2012). [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
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25. Harary and hyper-Wiener indices of some graph operations.
- Author
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Balamoorthy, S., Kavaskar, T., and Vinothkumar, K.
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DIVISOR theory , *MATHEMATICS - Abstract
In this paper, we obtain the Harary index and the hyper-Wiener index of the H-generalized join of graphs and the generalized corona product of graphs. As a consequence, we deduce some of the results in (Das et al. in J. Inequal. Appl. 2013:339, 2013) and (Khalifeh et al. in Comput. Math. Appl. 56:1402–1407, 2008). Moreover, we calculate the Harary index and the hyper-Wiener index of the ideal-based zero-divisor graph of a ring. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
26. Theta lifts to certain cohomological representations of indefinite orthogonal groups.
- Author
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Miyazaki, Takuya and Saito, Yohei
- Subjects
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AUTOMORPHIC forms , *CUSP forms (Mathematics) , *MATHEMATICS - Abstract
Howe and Tan (Bull Am Math Soc 28:1–74, 1993) investigated a degenerate principal series representation of indefinite orthogonal groups O (b + , b -) and explicitly described its composition series. In particular it contains a unique unitarizable irreducible submodule Π , which is isomorphic to a cohomological representation. In this paper we construct orthogonal automorphic forms locally corresponding to Π as theta liftings of holomorphic Mp 2 (R) cusp forms by using the Borcherds' method (Invent Math 132:491–562, 1998). We propose a special choice of Schwartz functions to define the liftings, which yields precise descriptions of their Fourier expansions. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
27. OPTICAL ART OF A PLANAR IDEMPOTENT DIVISOR GRAPH OF COMMUTATIVE RING.
- Author
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AUTHMAN, MOHAMMED N., MOHAMMAD, HUSAM Q., and SHUKER, NAZAR H.
- Subjects
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COMMUTATIVE rings , *DIVISOR theory , *IDEMPOTENTS , *GRAPH coloring , *PLANAR graphs , *MATHEMATICS - Abstract
The idempotent divisor graph of a commutative ring R is a graph with a vertex set in R* = R-{0}, where any distinct vertices x and y are adjacent if and only if x.y = e, for some non-unit idempotent element e^2 = e ∈ R, and is denoted by Л(R). Our goal in this work is to transform the planar idempotent divisor graph after coloring its regions into optical art by depending on the reflection of vertices, edges, and planes on the x or y-axes. That is, we achieve Op art solely through pure mathematics in this paper. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
28. Understanding Geometric Pattern and its Geometry Part 11 - Using Anatolian Seljuk Architecture as a Source of Inspiration for Students' Projects in Mathematics.
- Author
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Majewski, Mirosław
- Subjects
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STUDENT projects , *STONE carving , *GEOMETRY , *CLASSROOM activities , *HIGH school students , *MATHEMATICS - Abstract
In recent decades, with the continuous changes in the mathematics curriculum, many geometry-related topics were neglected or removed from our classroom activities. Thus, some teachers pursue these topics as independent students' projects. There is also a growing interest in various courses and workshops dealing with practical geometric pattern design. The author has taught courses and conducted workshops on geometry and pattern design at the Istanbul Design Center for many years. Participants in these events were high school and university students, artists, and architects. In this paper, we will discuss selected concepts of geometry used by Seljuk architects in designing the famous Seljuk geometric mosaics and stone carvings. We will show how these geometric concepts were used in selected examples from mosques, tombs, hans, and madrasas. We will also demonstrate using geometry software, e.g., Geometer's Sketchpad or GeoGebra, for constructing geometric patterns. [ABSTRACT FROM AUTHOR]
- Published
- 2024
29. Mark Burgin's Contribution to the Foundation of Mathematics.
- Author
-
Lev, Felix M.
- Subjects
- *
QUANTUM field theory , *QUANTUM electrodynamics , *MATHEMATICS - Abstract
In this paper, I attempt to describe Mark Burgin's results in non-Diophantine mathematics, which are important for the foundation of mathematics and its application in quantum field theory. In particular, the elimination of divergences in quantum electrodynamics is described. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
30. Importance of Understanding the Physical System in Selecting Separation of Variables Based Methods to Solve the Heat Conduction Partial Differential Equation.
- Author
-
Florio, Laurie A.
- Subjects
- *
HEAT conduction , *DIFFERENTIAL equations , *HEAT equation , *RANDOM forest algorithms , *PHENOMENOLOGICAL theory (Physics) , *MATHEMATICS - Abstract
Separation of variables is a common method for producing an analytical based solution to partial differential equations. Despite the wide application of this method, often the physical phenomena described by the differential equations are not adequately involved in the discourse over the appropriate methods to solve a given problem, particularly in mathematics curricula. However, as mathematics is the tool to better understanding of the physical world, the meaning of the differential equation, boundary conditions, and initial conditions cannot be detached from the methods used to solve the differential equations. Failure to recognize the physical conditions being studied can lead to solution methods that are invalid or unphysical. This paper demonstrates how awareness of the physical nature of the system being investigated and its relationship to the mathematics can guide the selection of the relevant solution methods. To illustrate the importance of the comprehension of the physical meaning behind the mathematical equations and representations and the need to avoid rote application a solution technique, the logic behind the selection of the appropriate solution techniques for the one-dimensional transient heat conduction equation is considered under different imposed conditions which lead to different trends in system operation. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
31. Scalable DPG multigrid solver for Helmholtz problems: A study on convergence.
- Author
-
Badger, Jacob, Henneking, Stefan, Petrides, Socratis, and Demkowicz, Leszek
- Subjects
- *
MULTIGRID methods (Numerical analysis) , *BENCHMARK problems (Computer science) , *DEGREES of freedom , *THEORY of wave motion , *HELMHOLTZ equation , *MATHEMATICS - Abstract
This paper presents a scalable multigrid preconditioner targeting large-scale systems arising from discontinuous Petrov–Galerkin (DPG) discretizations of high-frequency wave operators. This work is built on previously developed multigrid preconditioning techniques of Petrides and Demkowicz (Comput. Math. Appl. 87 (2021) pp. 12–26) and extends the convergence results from O (10 7) degrees of freedom (DOFs) to O (10 9) DOFs using a new scalable parallel MPI/OpenMP implementation. Novel contributions of this paper include an alternative definition of coarse-grid systems based on restriction of fine-grid operators, yielding superior convergence results. In the uniform refinement setting, a detailed convergence study is provided, demonstrating h and p robust convergence and linear scaling with respect to the wave frequency. The paper concludes with numerical results on hp -adaptive simulations including a large-scale seismic modeling benchmark problem with high material contrast. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
32. APPLICATION OF HE’S FREQUENCY FORMULA TO NONLINEAR OSCILLATORS WITH GENERALIZED INITIAL CONDITIONS.
- Author
-
Jian-Gang Zhang, Qing-Ru Song, Jian-Qiang Zhang, and Fang Wang
- Subjects
- *
DUFFING equations , *NONLINEAR systems , *NONLINEAR oscillators , *RELIABILITY in engineering , *ENGINEERS , *MATHEMATICS - Abstract
This paper focuses on the vibration periodic property of Duffing oscillator with generalized initial conditions. Firstly, the undamped case is solved by Ji-Huan He’s frequency formulation; Secondly, the formulation is extended to the damped case. Numerical verification shows that the frequency formulation is mathematically simple and physically insightful and practically applicable. This paper paves a novel way for engineers to use the formulation to study nonlinear vibration system with ease and reliability. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
33. ON QUANTUM HERMITE-JENSEN-MERCER INEQUALITIES.
- Author
-
BUDAK, HÜSEYIN and KARA, HASAN
- Subjects
- *
VARIATIONAL inequalities (Mathematics) , *INTEGRALS , *MATHEMATICS , *STATISTICS - Abstract
A. M. Mercer prove a new version of well-known Jensen inequality which is called Jensen-Mercer inequality [16]. By using Jensen-Mercer inequality, Kian andMoslehian establish a new variant of Hermite-Hadamard inequality which is called Hermite-Jensen-Mercer inequality [15]. In this paper, we extend the Hermite-Jensen-Mercer inequality for quantum integrals by utilizing Jensen-Mercer inequality. Then we investigate the connections between our results and those in earlier works. Moreover we give some examples to illustrate the main results in this paper. This is the first paper focusing on Hermite-Jensen-Mercer inequalities for quantum integrals. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
34. The Solipsist's First Paper.
- Author
-
Sixta, Sabrina
- Subjects
- *
MATHEMATICS - Published
- 2022
- Full Text
- View/download PDF
35. A relation-theoretic set-valued version of Prešić-Ćirić theorem and applications.
- Author
-
Shukla, Satish, Rai, Shweta, and Shukla, Rahul
- Subjects
- *
METRIC spaces , *MATHEMATICS - Abstract
In this paper, we establish a relation-theoretic set-valued version of the fixed point result of Ćirić and Prešić (Acta Math. Univ. Comen. LXXVI(2):143–147, 2007) on metric spaces endowed with an arbitrary binary relation. The results of this paper, generalize and unify the fixed point results of Ćirić and Prešić (Acta Math. Univ. Comen. LXXVI(2):143–147, 2007), Shukla and López (Quaest. Math. 45(3):1–16, 2019), and Shukla and Radenović (An. Ştiinţ. Univ. 'Al.I. Cuza' Iaşi, Mat. 63(2):339–350, 2017) in product spaces. Some examples are provided that justify and establish the importance of our results. As applications of our main result, we have established the existence of solutions to differential inclusion problems and the weak asymptotical stability and a global attractivity of the equilibrium point of a difference inclusion problem. The use of arbitrary binary relations in our results permits us to apply the results to the differential inclusion problems and difference inclusion problems with weaker assumptions than those used in the papers mentioned above. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
36. Mathematical Methods for an Accurate Navigation of the Robotic Telescopes.
- Author
-
Savanevych, Vadym, Khlamov, Sergii, Briukhovetskyi, Oleksandr, Trunova, Tetiana, and Tabakova, Iryna
- Subjects
- *
TELESCOPES , *ROBOTICS , *SIGNAL-to-noise ratio , *NAVIGATION , *STANDARD deviations , *IDENTIFICATION - Abstract
Accurate sky identification is one of the most important functions of an automated telescope mount. The more accurately the robotic telescope is navigated to the investigated part of the sky, the better the observations and discoveries made. In this paper, we present mathematical methods for accurate sky identification (celestial coordinates determination). They include the automatic selection of the reference stars, preliminary and full sky identification, as well as an interaction with international databases, which are a part of the astrometric calibration. All described methods help to receive accurately calculated astrometric data and use it for the positional calibration and better navigation of the automated telescope mount. The developed methods were successfully implemented in the Collection Light Technology (CoLiTec) software. Through its use, more than 1600 small solar system objects were discovered. It has been used in more than 700,000 observations and successful sky identifications, during which, five comets were discovered. Additionally, the accuracy indicators of the processing results of the CoLiTec software are provided in the paper, which shows benefits of the CoLiTec software and lower standard deviation of the sky identification in the case of low signal-to-noise ratios. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
37. Benefits of Risk-Taking in Teaching Mathematics.
- Author
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KIRMIZI, Mehmet, QUANSAH, Abigail, and BUBER, Zafer
- Subjects
- *
MATHEMATICS education , *TEACHING methods , *MATHEMATICS students , *MATHEMATICS , *EDUCATIONAL outcomes , *GRADUATE students - Abstract
In this paper, we, a group of graduate students in mathematics education, discuss some of the metacognitive benefits of the non-traditional teaching methods we observed employed by one of our professors. This professor's methods challenge the common belief that well-managed class time is key for positive learning outcomes. Instead, he orients his teaching to share the exploration and sense-making phases of doing mathematics. The goal of his teaching is to share the idea that learning mathematics is a process of "refining our mathematical thinking". We argue that this approach to teaching helps students see that mathematics is a human endeavor, appreciate the cycles of learning mathematics and the importance of struggle throughout the process, and gain some insight on what it means to be an expert in mathematics. We encourage teachers and professors to move away from obsessing about structured, well-organized class time, and to instead move towards having flexible and risk-oriented class time. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
38. Sharing Four Biscuits Between Three People: An Illustrative Example of How Mathematics is Intertwined with Human Values.
- Author
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Sumpter, Lovisa and Sumpter, David
- Subjects
- *
VALUES (Ethics) , *BISCUITS , *MACHINE learning , *PHILOSOPHERS , *MATHEMATICIANS , *MATHEMATICS - Abstract
Despite convincing arguments by mathematicians, philosophers, sociologists and machine learning practitioners to the contrary, there remains a widespread notion amongst many members of the general public (and some practitioners) that mathematics is neutral, that it is free from human values. One reason why this notion persists is that we lack clear-cut examples that demonstrate how mathematics and values are intertwined. In this paper, we offer one such example. In particular, we show that when sharing four biscuits between three people, several possible mathematical and ethical frameworks can be used. We demonstrate that different solutions--hiding one biscuit, arbitrarily sharing the extra biscuit, randomizing allocation, dividing the extra biscuit into three parts, and successively dividing it into smaller and smaller parts--involve different mathematical methods and evoke different human values. We discuss the construction of quantum biscuit splitting devices and the use of machine learning to divide biscuits. We argue that the multitude of different mathematically-correct solutions to this problem (each with its own ethical justification) might influence the values held by practicing mathematicians. The example we propose here has been used in teaching to help students understand why mathematics cannot be cleanly separated from human values. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
39. Finding Your Mathematical Roots: Inclusion and Identity Development in Mathematics.
- Author
-
McGuire, Linda
- Subjects
- *
IDENTITY (Psychology) , *SCIENTIFIC knowledge , *GENEALOGY , *UPPER level courses (Education) , *MATHEMATICS , *CONSTRUCTION projects - Abstract
This paper details a semester-long course project that has been successfully adapted for use in mathematics courses ranging from introductory level, generaleducation classes to advanced courses in the mathematics major. Through creating aspirational mathematical family trees and writing mathematical autobiographies, this assignment is designed to help battle belonging uncertainty, to challenge students to self-situate in relation to the history of mathematical and scientific knowledge, and to make visible a student's developing identity in mathematics and, more broadly, in STEM. The construction and scaffolding of the project, assignments, examples of student work, foundational readings, assessment and outcomes, and adaptation strategies for various classroom settings are discussed in detail. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
40. Some existence and uniqueness results for a solution of a system of equations.
- Author
-
KHANTWAL, DEEPAK and PANT, RAJENDRA
- Subjects
- *
EQUATIONS , *METRIC spaces , *MATHEMATICS - Abstract
This paper presents some existence and uniqueness results for a solution of a system of equations. Our results extend and generalize the well-known and celebrated results of Boyd and Wong [Proc. Amer. Math. Soc. 20 (1969)], Matkowski [Dissertations Math. (Rozprawy Mat.) 127 (1975)], Proinov [Nonlinear Anal. 64 (2006)], Ri [Indag. Math. (N. S.) 27 (2016)] and many others. We also present some illustrative examples to validate our results. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
41. La relación entre ansiedad y rendimiento académico en los estudiantes ecuatorianos de 15 años.
- Author
-
MENESES-BUCHELI, KARLA, YÁNEZ-ARCOS, ANDREA, ZEVALLOS-POLO, DIANA, and CARRANZA-VILLARROEL, CARLOS
- Abstract
Anxiety is a state of mind of intense worry that can affect students' performance both positively and negatively. Internationally, recent studies show high percentages of students diagnosed with anxiety and depression. This paper seeks to quantitatively analyze how anxiety is related to academic performance in Ecuadorian students. An Ordinary Least Squares (OLS) model with school fixed effects estimates an educational production function. The results confirm that, up to certain levels of anxiety, students' scores improve. However, once anxiety levels are elevated -a threshold that is higher for male students-scores are negatively affected. These findings are relevant for two reasons. First, during adolescence, experiences and interpersonal relationships impact personality construction and influence the development of cognitive, non-cognitive and emotional skills. Second, given the current post-pandemic situation, in which anxiety is a frequent scenario. This research concludes that it is necessary to reflect on the importance of rethinking pedagogical processes in schools and to analyze strategies to introduce mental health in the school curriculum. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
42. Neutrosophic -Structures in Semimodules over Semirings.
- Author
-
Muhiuddin, Ghulam, Abughazalah, Nabilah, Elavarasan, Balasubramanian, Porselvi, Kasi, and Al-Kadi, Deena
- Subjects
- *
TWENTY-first century , *STRUCTURAL frames , *MATHEMATICS , *SYMMETRY - Abstract
The study of symmetry is a fascinating and unifying subject that connects various areas of mathematics in the twenty-first century. Algebraic structures offer a framework for comprehending the symmetries of geometric objects in pure mathematics. This paper introduces new concepts in algebraic structures, concentrating on semimodules over semirings and analysing the neutrosophic structure in this context. We explore the properties of neutrosophic subsemimodules and neutrosophic ideals after defining them. We discuss, utilizing neutrosophic products, the representations of neutrosophic ideals and subsemimodules, as well as the relationship between neutrosophic products and intersections. Finally, we derive equivalent criteria in terms of neutrosophic structures for a semiring to be fully idempotent. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
43. DisCrit noticing: Theorizing at the intersections of race and ability in mathematics education.
- Author
-
Yeh, Cathery
- Subjects
- *
RACE , *MATHEMATICS education , *CRITICAL race theory , *INTERSECTIONALITY , *MATHEMATICS , *ABLEISM - Abstract
While there is increased attention to power, privilege, and access in mathematics education, conversations around race and disability are often left out of the conversation. Disability in mathematics continues to be studied with a lens that focuses on behavior, rather than attending to the situated and sociopolitical context in which teaching and learning takes place. This paper specifically calls on the importance of an intersectional analysis of ability and the need for explicit conversation on the interwoven nature of race and disability to uncover exclusionary practices of hyper‐labeling, hyper‐surveilling, and hyper‐punishing for those outside notions of normalcy. Drawing on sociopolitical perspectives informed by Disability Critical Race Theory (DisCrit) and DisCrit Classroom Ecology, I share a framework of DisCrit noticing to consider the interwoven nature of racism and ableism in mathematics classrooms, provide a context to develop preservice teacher DisCrit noticing during mathematics methods, and a case example to highlight implications and transformative possibilities for (re)organizing classrooms through the DisCrit noticing framework. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
44. Framed mapping class groups and the monodromy of strata of abelian differentials.
- Author
-
Calderon, Aaron and Salter, Nick
- Subjects
- *
ABELIAN groups , *MATHEMATICS , *RIEMANN surfaces , *MONODROMY groups , *GROUP theory - Abstract
This paper investigates the relationship between strata of abelian differentials and various mapping class groups afforded by means of the topological monodromy representation. Building off of prior work of the authors, we show that the fundamental group of a stratum surjects onto the subgroup of the mapping class group which preserves a fixed framing of the underlying Riemann surface, thereby giving a complete characterization of the monodromy group. In the course of our proof we also show that these “framed mapping class groups” are finitely generated (even though they are of infinite index) and give explicit generating sets. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
45. Some combinatorial identities containing central binomial coefficients or Catalan numbers.
- Author
-
Feng Qi, Da-Wei Niu, and Dongkyu Lim
- Subjects
- *
CATALAN numbers , *BINOMIAL coefficients , *MATHEMATICS - Abstract
In the article, by virtue of Maclaurin's expansions of the arcsine function and its square and cubic, the authors (1) give a short proof of a sum formula of a Maclaurin's series with coefficients containing reciprocals of the Catalan numbers; (2) establish four sum formulas for finite sums containing the ratio or product of two central binomial coefficients or the Catalan numbers. The instant proof simplifies discussions in the journal papers: College Math. J. 43 (2012), no. 2, 141-146; Amer. Math. Monthly 121 (2014), no. 3, 267-267; Amer. Math. Monthly 123 (2016), no. 4, 405-406; Elem. Math. 71 (2016), no. 3, 109-121; and Mathematics 5 (2017), no. 3, Article 40, 31 pages. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
46. Well-Posedness of a Class of Radial Inhomogeneous Hartree Equations.
- Author
-
Almuthaybiri, Saleh, Ghanmi, Radhia, and Saanouni, Tarek
- Subjects
- *
SOBOLEV spaces , *EQUATIONS , *NONLINEAR equations , *MATHEMATICS - Abstract
The present paper investigates the following inhomogeneous generalized Hartree equation i u ˙ + Δ u = ± | u | p − 2 | x | b (I α ∗ | u | p | · | b) u , where the wave function is u : = u (t , x) : R × R N → C , with N ≥ 2 . In addition, the exponent b > 0 gives an unbounded inhomogeneous term | x | b and I α ≈ | · | − (N − α) denotes the Riesz-potential for certain 0 < α < N . In this work, our aim is to establish the local existence of solutions in some radial Sobolev spaces, as well as the global existence for small data and the decay of energy sub-critical defocusing global solutions. Our results complement the recent work (Sharp threshold of global well-posedness versus finite time blow-up for a class of inhomogeneous Choquard equations, J. Math. Phys. 60 (2019), 081514). The main challenge in this work is to overcome the singularity of the unbounded inhomogeneous term | x | b for certain b > 0 . [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
47. Holomorphic H{o}rmander-type functional calculus on sectors and strips.
- Author
-
Haase, Markus and Pannasch, Florian
- Subjects
- *
CALCULUS , *HOLOMORPHIC functions , *MULTIPLIERS (Mathematical analysis) , *MATHEMATICS - Abstract
In this paper, the abstract multiplier theorems for 0-sectorial and 0-strip type operators by Kriegler and Weis [Math. Z. 289 (2018), pp. 405–444] are refined and generalized to arbitrary sectorial and strip-type operators. To this end, holomorphic Hörmander-type functions on sectors and strips are introduced, with even a finer scale of smoothness than the classical polynomial scale. Moreover, we establish alternative descriptions of these spaces involving Schwartz and "holomorphic Schwartz" functions. Finally, the abstract results are combined with a result by Carbonaro and Dragičević [Duke Math. J. 166 (2017), pp. 937–974] to obtain an improvement—with respect to the smoothness condition—of the known Hörmander-type multiplier theorem for general symmetric contraction semigroups. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
48. A remark about asymptotic stability in Duffing equations: lateral stability in Comb-drive finger MEMS.
- Author
-
Núñez, D. and Murcia, L.
- Subjects
- *
DUFFING equations , *FINGERS , *MATHEMATICS - Abstract
In this short paper we tackle two subjects. First, we provide a lower bound for the first eigenvalue of the antiperiodic problem for a Hill's equation based on L p -conditions, and as a consequence, we introduce an adjusted statement of the main result about the asymptotic stability of periodic solutions for the general Duffing equation in (Torres in Mediterr. J. Math. 1(4):479–486, 2004) (Theorem 4). This appropriate version of the result arises because of one subtlety in the proof provided in (Torres in Mediterr. J. Math. 1(4):479–486, 2004). More precisely, the lower bound of the first antiperiodic eigenvalue associated with Hill's equations of potential a (t) employed there may be negative, thus the conclusion is not completely attained. Hence, the adjustments considered here provide a mathematically correct result. On the other hand, we apply this result to obtain a lateral asymptotic stable periodic oscillation in the Comb-drive finger MEMS model with a cubic nonlinear stiffness term and linear damping. This fact is not typical in Comb-drive finger devices, thus our results could provide a new possibility; a new design principle for stabilization in Comb-drive finger MEMS. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
49. Domination parameters of the splitting graph of a graph.
- Author
-
Deepalakshmi, J., Marimuthu, G., Somasundaram, A., and Arumugam, S.
- Subjects
- *
PARAMETERS (Statistics) , *MATHEMATICS , *RATIONAL numbers , *INTEGERS , *MATHEMATICAL constants - Abstract
Let G = (V;E) be a graph of order n and size m: The graph Sp(G) obtained from G by adding a new vertex v0 for every vertex v 2 V and joining v0 to all neighbors of v in G is called the splitting graph of G: In this paper, we determine the domination number, the total domination number, connected domination number, paired domination number and independent domination number for the splitting graph Sp(G):. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
50. Dynamics of a periodic-parabolic Lotka–Volterra competition-diffusion system in heterogeneous environments.
- Author
-
Xueli Bai, Xiaoqing He, and Wei-Ming Ni
- Subjects
- *
REACTION-diffusion equations , *SPATIAL analysis (Statistics) , *LOTKA-Volterra equations , *MATHEMATICS , *EIGENVALUES - Abstract
The effects of spatial heterogeneity on the dynamics of reaction-diffusion models have been studied extensively. In particular, global dynamics of general spatially heterogeneous (but temporally static) Lotka–Volterra competition-diffusion systems were completely clarified by He and Ni in 2016. However, the evolutionary impacts of temporal periodicity combined with spatial heterogeneity in population ecology remain a challenging issue. In this work, we consider a population model of two competing species in a both spatially varying and temporally periodic environment, where the two species only differ in their random dispersal rates but are otherwise ecologically identical. In a pioneering 2001 work on this model by Hutson et al., by constructing various choices of resource functions and dispersal rates of the two species, the authors demonstrated that all the following three types of dynamics are possible: (i) stable coexistence of the two species; (ii) the slower diffuser invades the faster one but not vice versa; (iii) the faster diffuser invades the slower one but not vice versa. This is in drastic contrast with the spatially heterogeneous but temporally static case, where Dockery et al. showed in 1998 that the slower diffuser always wipes out the faster one. In this paper, we completely and explicitly characterize the asymptotic stability of both semitrivial periodic solutions in terms of the two dispersal rates and the resource function, when either dispersal rate is sufficiently small or large. In particular, the direction of selection on the dispersal rate during the evolution can be elucidated in these instances. Some novel analytical methods are developed to investigate asymptotic behaviors of the underlying time-periodic parabolic eigenvalue problem and its adjoint problem. We hope that these methods are of independent interest in the area of time-periodic parabolic equations. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
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