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The paper describes the results of a study whose main aim was to find the interrelationship between pupils' school grades in Czech language (native), mathematics, and physics and pupils' cognitive predispositions to problem-solving in science and mathematics diagnosed by the Lawson Classroom Test of Scientific Reasoning and the Culture of Problem Solving test. A total of 180 pupils from the Czech Republic aged 14-15 took part in this study. The results show that pupils with better grades in the monitored subjects achieve better results in both tests. It also turns out that there are generally statistically insignificant differences between the results of pupils assessed by grades 1 or 2 and between those assessed by grades 3 or 4. Pupils' performance in the two tests might help to strengthen the objectivization of grading at school. They might also help identify the indicators important for developing problem-solving skills. The research specifically points to the need to develop algebraic thinking, the conception of infinity, spatial imagination, geometric imagination in the plane, proportional reasoning, and the ability to control variables.

Gaming the system is a persistent problem in Computer-Based Learning Platforms. While substantial progress has been made in identifying and understanding such behaviors, effective interventions remain scarce. This study uses a method of causal moderation known as Fully Latent Principal Stratification to explore the impact of two types of interventions--gamification and manipulation of assistance access on the learning outcomes of students who tend to game the system. The results indicate that gamification does not consistently mitigate these negative behaviors. One gamified condition had a consistently positive effect on learning regardless of students' propensity to game the system, whereas the other had a negative effect on gamers. However, delaying access to hints and feedback may have a positive effect on the learning outcomes of those gaming the system. This paper also illustrates the potential for integrating detection and causal methodologies within educational data mining to evaluate effective responses to detected behaviors.

Literature has established that some learners encountered difficulties solving first order ordinary differential equations (ODEs). The use of error analysis in teaching ODEs is believed to make essential contribution towards calculus knowledge development. This paper therefore focuses on analyzing pre-service teachers' (PSTs) errors and misconceptions apropos of first order ODEs. The paper analyzed the nature of errors made in a test which was written by PSTs on the above topic. The test comprised various types of first order differential equations such as ODEs with separable variables, exact ODEs, ODEs that needed integrating factors, linear ODEs, and homogeneous ODEs. The purpose was to investigate the challenges faced by PSTs in various types of ODEs and the nature of misconceptions that they had in each particular type. This is a qualitative study that involved 63 PSTs who wrote a test on ODEs after being taught the topic for two weeks. The authors marked the work in order to ascertain the misconceptions and errors exhibited by the participants in the test. The PSTs' performance in the test was analyzed using the SOLO taxonomy and the Newman's theory mistake analysis. The study established that the topic was rather difficult for PSTs due to various reasons that included, among others, knowledge gaps in integration rules, algebraic computations and, in rare cases, differentiation, as well as misapplication of the rules of natural logarithms. This research therefore recommends that mathematics teacher educators ought to rather focus on the concept of integration and basic algebra before introducing the topic on ODEs to teachers on training.

The aim of this paper is to review some studies conducted with different learning areas in which the schemes of different participants emerge. Also it is about to show how mathematical proofs are handled in these studies by considering Harel and Sowder's classification of proof schemes with specific examples. As a result, it was seen that the examined studies we readdressed in the learning areas of Analysis, Geometry, Algebra, Linear Algebra, Elementary Number Theory, Probability, Combinatorics, and MIX. Students in early grades tend more towards external and empirical proof schemes. On the other hand, the characteristics of the proof schemes become more sophisticated as the participants' profiles change to pre-service teachers or as they become more specializing in mathematics. Some results are as follows: the academic achievement levels, genders, and grade levels of the participants in the studies examined in this paper have indicated that they have similar traces with the schemes they use. In addition, it has been determined that new perspectives such as examining Harel and Sowder's classification with new lenses, revealing the overlooked roles of some dynamics in proof, or improving the framework provide an important research area in terms of revealing students' potentials.

[This paper is part of the Focused Collection on Instructional labs: Improving traditions and new directions.] This paper presents a historical analysis of the development, implementation, research, and assessment of an evidence-based introductory algebra-based physics course. The course is laboratory based and taught with an inquiry-based pedagogy. The course has remained unique and has been taught consistently for over 20 years. It is taught predominantly to health science majors and is completely laboratory based without a lecture and without a required text. Students learn by working through a guided inquiry manual in groups, doing experiments to explore the nature of the world around them. They develop both quantitative and qualitative models based on their experiments. The focus is as much on critical thinking, modeling, and thinking like a scientist, as on physics content. I discuss the course throughout the years, presented in the context of the field of physics education research historically and the state of our department locally. The results of multiple forms of assessment are presented chronologically. The assessments were designed to answer research questions about the students' conceptual understanding and thinking skills, the effects of class size expansion, and questions about learning assistants' pedagogical content knowledge. One finding was that the conceptual understanding of students in the inquiry-based course was significantly higher than students taught traditionally but not significantly different from students taught by other research-informed pedagogies. However, we found that students taught in the inquiry-based format showed more evidence of the application of thinking skills as assessed by our thinking skills rubric in free-response exam problems. We have demonstrated that it is possible to expand a laboratory-based, inquiry-based physics course from sections of 24 students to sections of 60 students with the help of learning assistants and we have developed and validated a set of questions that can be used to measure learning assistants' pedagogical content knowledge or for learning assistant training purposes.

Educational research has reported different benefits related to the use of practice tests. In the case of the teaching and learning of mathematics, evidence has been found that the use of practice tests is associated with an improved performance in standardized tests. However, it is less known about the emotions that students experience during such practice tests. This paper reports on a study on the use of practice test in mathematics instruction at the undergraduate level, which focuses on exploring students' emotions during a practice test for linear algebra. 78 students answered a questionnaire one day after having participated in an oral practice test on linear algebra. The results suggest that before the practice test nervousness was predominant among students, but this emotion decreases as the activity progresses.

The present study explored 285 11th-grade students' preconceptions, misconceptions, and errors in solving mathematics tasks by graphical method. A descriptive-explorative study design was adopted. Cluster sampling was used to select students from sampled secondary schools in eastern and central Uganda. Students' paper and pen solution sketches together with the task-based interviews were used to identify students' preconceptions, misconceptions, and errors in linear programming (LP). Students' responses were analyzed thematically and interpreted as students' learning gaps. The results indicated that students lacked proficiency in relating basic algebraic concepts and procedures to the mathematical language with which LP is conveyed. Generally, most students could not adequately use their previous knowledge and connect it to the learning and solving of LP tasks. Besides applying wrong mathematical algebraic concepts, students had difficulties interpreting and writing correct models (inequalities) from LP word problems. Misconceptions and errors were common and peculiar to and in individual student's solution sketches especially in applying the concepts of equations and inequalities to graphically solve and optimize LP tasks. Students held extremely weak concept images of graphing equations, and inequalities and their linkage to optimizing feasible regions. This research provides insight into the learning of mathematics word problems(LP) and recommends that mathematics educators should effectively apply students' preconceptions, misconceptions, and errors as opportunities for enhancing students' LP conceptual changes. For mathematical proficiency, suitable learning approaches, methods, and strategies should be adapted to address specific individual student's flawed conceptual and procedural knowledge and understanding. These approaches may guide educators in helping students to construct the connections between the old and the new knowledge.

This paper examines Black Algebra I educators' perceptions of their experiences in a professional learning community, "Algebra I Academy," designed specifically to equip Black Algebra I educators with liberatory pedagogical practices for their instruction with Black students taking Algebra I. Utilizing survey and focus group data from Black Algebra I educators who participated in the Algebra I Academy, findings from this study indicate that the Algebra I Academy had a positive effect on Black Algebra I educators by creating a sense of community with fellow Black Algebra I educators, providing a space for Black Algebra I educators to reimagine who they are as Black math educators, and by offering a collaborative space for Black Algebra I educators to learn and apply new, more liberatory, Algebra I pedagogical practices. More universally, this study highlights the need and value-add of educator learning communities that are racially affinity-based, professional learning spaces that are responsive to the historical and contemporary socio-racial contexts of educators' lives in and outside of schooling, and attentive to the social and emotional, as well as pedagogical, needs of educators.

The study of students' use of representations is one of the main topics of physics education research and is guided by the overarching field of semiotics. In this paper we compare two semiotic frameworks, one coming from didactics of mathematics and one from physics education research; "the theory of registers of semiotic representations" and "social semiotics," using the networking of theories methodology. A group of first year university students were audio and video recorded as they discussed concepts relating to thermal energy, a study that will be further explored in an upcoming paper. We find that analyzing the recorded data using two different semiotic perspectives provides a wider interpretation of students' representational use, a descriptive approach to how students use the representations, and an approach to the cognitive aspects of the construction of knowledge. By comparing the theoretical constructs they employ, and how they are employed in the analysis process, we identify constructs that both frameworks have in common, but also where they differ. We have found that each semiotic theory provides a different perspective regarding students' representational use. We also propose that comparing different theories may provide a space for complementing the constructs of each theory and providing a bigger picture to understand students' representational use in physics and other science, technology, engineering, and mathematics education areas.

Physics and mathematics are interrelated as part of the science, technology, engineering, and mathematics (STEM) disciplines. The learning of science is supported by mathematical skills and knowledge. The aim of this paper is to determine the cognitive obstacles of in-service undergraduate physics student-teachers' understanding of the concept of complex numbers which is part of linear algebra. A case study is presented involving 10 undergraduate student-teachers at a university in Zimbabwe studying for a Bachelor of Science Education Honours Degree in physics. Data were generated from the 10 participants' answers to structured activity sheets and interviews. Action, process, object, schema (APOS) theory was used to explore the possible ways that students may follow to understand the concepts of complex numbers and how they concur with the preliminary genetic decomposition. It was observed that most of the participants were operating at the action level, with a few operating at the process and object levels of understanding. Recommendations are made in this study that instructors should pay more attention to the prerequisite concepts and the "met afters" so that students can encapsulate processes into object understanding of division of complex numbers and polar form.

Recent research has boosted the inclusion of introductory group theory into secondary and undergraduate mathematics education due to manifold potentials, e.g., with regards to the promotion of students' abstract thinking. However, in addition to research on cognitive processes, learners' affective characteristics have largely remained unexplored in the context of teaching and learning group theory to date. In this paper, we contribute to closing this gap: We report on an empirical study investigating n=143 students' affective characteristics within a two-weeks course program--the Hildesheim teaching concept. In our study, this concept was used to introduce pre-service primary teachers into group theory. A multiple linear regression analysis reveals that neither mathematics-specific ability self-concept nor subject interest are significant predictors of the achieved conceptual understanding of group theory after the intervention indicating that group theory is not reserved for only the mathematically interested students or students with a high mathematics-specific self-concept.

This paper aims to show how through plausible reasoning financial mathematics can be taught at the university level, the work is based on a model designed by García (2019), who created it to teach linear algebra in engineering careers, using technology, of all this model, only the design with methodological procedure is adapted. In this grade The theories corresponding to money management will be developed over time, allowing you to obtain a solid foundation in the management and application of simple and compound interest in different financial applications, which will be the prerequisite to continue your studies in financial evaluation of projects , in which he will use these tools for financial decision making. In addition, this course will implement the use of spreadsheets, to facilitate and expedite the respective calculations, thus giving the student a broad overview and useful resource for their future work performance as a professional.

This study explores student flexibility in mathematics by examining the relationship between accuracy and strategy use for solving arithmetic and algebra problems. Core to procedural flexibility is the ability to select and accurately execute the most appropriate strategy for a given problem. Yet the relationship between strategy selection and accurate execution is nuanced and poorly understood. In this paper, this relationship was examined in the context of an assessment where students were asked to complete the same problem twice using different approaches. In particular, we explored (a) the extent to which students were more accurate when selecting standard or better-than-standard strategies, (b) whether this accuracy-strategy use relationship differed depending on whether the student solved a problem for the first time or the second time, and (c) the extent to which students were more accurate when solving algebraic versus arithmetic problems. Our results indicate significant associations between accuracy and all of these aspects--we found differences in accuracy based on strategy, problem type, and a significant interaction effect between strategy and assessment part. These findings have important implications both for researchers investigating procedural flexibility as well as secondary mathematics educators who seek to promote this capacity among their students.

Algebraic thinking is a method of solving math problems that stresses the significance of general connections. Excellent algebraic thinking necessitates strong symbolization and generalization ability. Students aged 7 to 15 are at the Piaget thinking stage's formal operational stage. Teachers, especially those working with secondary school students, must be aware of how kids think and reason algebraically. A detailed literature review provides an overview of research on algebraic thinking. The goal of this study was to compile a list of full-text papers that presented empirical research on algebraic thinking. The "algebraic thinking" search phrase was used to search the ERIC and Scopus databases. A total of 36 studies were included in the review. The educational levels, participants, nations, research methodologies, study objectives, data collecting tools, and analytic approaches have all been considered in studies on algebraic thinking. The number of studies published has risen over time. 2019 was the year with the most studies. The majority of the research was carried out in the United States of America. The majority of the participants in the study were elementary and secondary school pupils. Teachers' knowledge, elements impacting algebraic thinking, relations, and comprehension, as well as measuring categories, were determined when the study was grouped according to the study's topic. The algebraic thinking exam was the most popular data gathering instrument. The qualitative technique was used in the study of algebraic thinking. The most common method was found to be qualitative analysis. While inferential statistics are preferred in quantitative techniques, latent class analysis, cluster analysis, and test development analysis are used depending on the study design. According to the results, it was stated that in-service or pre-service teacher training is needed for the development of algebraic thinking and non-routine activities such as games should be used in the classroom. In addition, it has been determined that teaching strategies such as geometry representation, multiple representation strategies, mental computational activity also improve algebraic thinking.

We provide a detailed description of a purposefully sampled tutoring session during which a student with a learning disability displayed common tendencies we have seen in our work on algebra teaching. The student struggled with solving equations in general and especially with distribution and knowing how to distribute terms and what steps to take in the correct order. The tutor responded by helping the student offload information, gesturing while speaking with the student, and asking questions strategically to both support and challenge the student to think critically. The purpose of this paper is to provide, through a case study, an accessible description for teachers and researchers of how students with learning disabilities interact with algebra and how teachers can support and challenge these students in this context.

In this paper, we report the analysis of thought processes used by Pre-Service Teachers' (PSTs') through clinical interviews as they solved an algebra task involving a linear pattern. The PST's were asked about a mathematical model they had constructed to describe a pattern problem. Our analysis suggests that conflict factors arise due to incompatibility in participants' personal concept definition and the formal concept definition of continuity. We identified how personal concept definitions of the participants differed and how this difference affected their decision on whether a graph was continuous or not.

This paper reflects on the outcome of lesson study in teaching the concept of algebraic equations utilizing quasi-variables. It also concurrently examines the integration of Ignatian values and social issues in learning the said concept. This study aimed to establish a culture of planning, collaboration, and reflection in developing the understanding and relevance of mathematical concepts in grade school through lesson study. The study showed how the process of lesson study was done given the following phases: planning phase, implementation phase, and post-lesson reflection and discussion phase. Emphasis on the planning phase was given on the details of the lesson design which aimed to integrate Ignatian values in the discussion while developing algebraic thinking from quasi-variable thinking delivered in the implementation phase. Findings highlighted on three statements: i) Collaborative lesson planning nurtures a deeper sense of scholarship and collegiality; ii) Building algebraic thinking from quasi-variable (arithmetic) thinking is a viable strategy for understanding the concept of algebraic equation; and iii) Looking into the "big picture" and responding to relevant social issues could strengthen meaning -- integration of Ignatian values. Strong collaboration and communication among teachers in creating detailed lesson design enabled more meaningful learning among pupils. Research revealed the significant role of lesson study in creating meaningful strategies and activities which provided efficient structure in developing a chosen lesson topic. It does not only focus on the nature of the topic but also include making meaningful connections to the real world and integrate values.

The acquisition of procedural and conceptual knowledge is imperative for the development of problem solving skills in mathematics. However, while there are mixed research findings on the relationship between the two domains of knowledge in some branches of mathematics, the relationship between learners' procedural and conceptual knowledge of algebra has not been well explored. This research paper examined the relationship between Grade 11 learners' procedural and conceptual knowledge of algebra. Data for the study was collected using an algebra test administered to 181 grade 11 learners in Gauteng province, South Africa. Descriptive statistics and Pearson's correlation coefficient were used to analyse the data in SPSS. The study revealed that the learners have low levels of both procedural and conceptual knowledge of algebra. However, they displayed better procedural knowledge than the conceptual knowledge of algebra. In addition, a statistically significant moderate positive linear relationship was found between the learners' procedural and conceptual knowledge of algebra.

This paper concerns with a product of circles induced by the quaternionic product considered in a projective manner. Several properties of this composition law are derived and on this way we arrive at some special numbers as roots or powers of unit. We extend this product to cycles as oriented circles and to pairs of circles by using the algebra of octonions. Three applications of the given products are proposed. [ABSTRACT FROM AUTHOR]

This research paper aims to characterize Mathematical Reasoning (MR) in teaching and learning of mathematics in high-school education. To achieve this goal and reveal the status of Mathematical Reasoning as a concept, we analyze the content of curricula and official textbooks of the initial and second year of high school in Morocco. Our analytical framework focuses on the commognitive perspective, exploiting the different components of MR presented in literature. The results obtained from this study using a quantitative approach show that MR occupies a central place in mathematics education at Moroccan high school, but the use of some structural and procedural aspects is still too limited.

This paper sought to explore the Knowledge of Algebra for Teaching and the algebra difficulties of In-field and Out-of-field Junior High School mathematics teachers using the expanded KAT framework. The study employed the descriptive survey design and involved the participation of 374 mathematics teachers using an achievement test instrument. The study projected School Algebra Knowledge as the prevailing knowledge domain and revealed that the two categories of Junior High School mathematics teachers possess knowledge that falls below average for five (5) out of the seven (7) algebra knowledge domains and also for the overall Knowledge of Algebra for Teaching. However, In-field mathematics teachers showed higher knowledge as compared to Out-of-field mathematics teachers in six (6) out of the seven (7) algebra knowledge domains as well as the overall Knowledge of Algebra for Teaching. Also, the research revealed that mathematics teachers with 5 or more years of teaching experience have higher Knowledge of Algebra for Teaching as compared to those with below 5 years of teaching experience. The study finally identified eight major algebra difficulties among Junior High School mathematics teachers. The findings of the study have implications for teacher preparation, policy and practice.

Nowadays, researchers are very interested in studying various Diophantine equations due to their importance in Cryptography, Chemistry, Knot Theory, Astronomy, Geometry, Trigonometry, Biology, Algebra, Electrical Engineering, Economics, and Astrology. The present paper is about the non-negative integer solution of the exponential Diophantine equation nx + 43y = z², where are non-negative integers, is a positive integer with nx + 43y = z², where n = 2 (mod 129) and n + 1 and is not a perfect square. The authors use the famous Catalan conjecture for this purpose. Results of the present paper indicate that 2, 3, 0, and 3 are the only required values of and respectively, that satisfy the exponential Diophantine equation, where are non-negative integers, is a positive integer with nx + 43y = z², where n = 2 (mod 129) and n + 1 and is not a perfect square. The present technique of this paper proposes a new approach to solving the Diophantine equations, which is the main scientific contribution of this study, and it is very beneficial, especially for researchers, scholars, academicians, and people interested in the same field. [ABSTRACT FROM AUTHOR]

The School of Engineering of the Polytechnic of Porto (ISEP) has embraced the DrIVE-MATH project, since September 2017. Active-learning (AL) techniques were implemented in several Math courses, namely Linear Algebra and Analytic Geometry, Probability and Statistics, Statistical Models, Computational Mathematics, and Differential and Integral Calculus I. In this paper, we will share the strengths, weaknesses, opportunities and threats of the implementation of the active-learning (AL) environment in these courses. We will detail the courses' plans, emphasizing the syllabus, pedagogical methodologies, assessment methods, students' perceptions, and other related issues. Several questionnaires were posed to the students enrolled in these Math courses during the last three academic years. The statistical analysis of the gathered data provided valuable indications of students' perceptions on the effectiveness of several AL methods, on the development of their own essential (soft+hard) skills. These skills will be a valuable resource to their future professional and personal lives. The 5th Industrial Revolution is just around the corner.

We present a case of one teacher's engagement in project-based learning for algebra I students. This teacher was a member of a cohort of mathematics teachers and career technical educators who participated in a two-week intensive summer institute investigating autonomous vehicles. During the academic year, the follow up support for these educators includes classroom support and monthly meetings where teachers give a formal presentation on their lessons. This paper presents the first of nine presentations that will be given by the mathematics educators during the 2020-2021 academic year. While her students loved the lesson, she reveals that the lesson will have to serve as an algebra I curriculum addon as she does not perceive that this activity will adequately prepare her students for the state mandated algebra I examination.

In this paper, we discuss some extensions of the Maligranda–Orlicz lemma. It deals with the problem of constructing a norm in a subspace of the space of bounded functions, for which it becomes a normed algebra so that the norm introduced is equivalent to the initial norm of the subspace. This is done by satisfying some inequality between these norms. We show in this paper how this inequality is relevant to the study of operator equations in Banach algebras. In fact, we study how to equip a subspace of the space of bounded functions with a norm equivalent to a given one so that it is a normed algebra. We give a general condition for the construction of such norms, which allows us to easily check whether a space with a given norm is an algebra with a pointwise product and the consequences of such a choice for measures of noncompactness in such spaces. We also study quasi-normed spaces. We introduce a general property of measures of noncompactness that allows the study of quadratic operator equations, prove a fixed-point theorem suitable for such problems, and complete the whole with examples and applications. [ABSTRACT FROM AUTHOR]

In this paper, we give a simple sufficient condition for the eigenvalue-separation properties of real tridiagonal matrices T. This result is much more than the statement that the pertinent eigenvalues are distinct. Its derivation is based on recurrence formulae satisfied by the polynomials made up by the minors of the characteristic polynomial det(xE - T) that are proven to form a Sturm sequence. This is a new result, and it proves the simple spectrum property of a symmetric tridiagonal matrix studied in a Grünbaum paper. Two numerical examples underpin the theoretical findings. The style of the paper is expository in order to address a large readership. [ABSTRACT FROM AUTHOR]

Consider an infinite-dimentional Banach space denoted as X, and designate ∂(X) as the algebra of all bounded linear operators on X. Moreover, let s (A) denote the spectrum of ..., and ...(A)) indicate the boundary of s (A). A map ... is termed a ρ-spectrum if ... (A) for all A ... In this paper, we characterize all surjective maps f1 and f2 on ρ(X) satisfying ... = (AB) for all A,B(X). [ABSTRACT FROM AUTHOR]

In this paper, we investigate the necessary and sufficient conditions for solving a dual split quaternion matrix equation A X B   =   C , and present the general solution expression when the solvability conditions are met. As an application, we delve into the necessary and sufficient conditions for the existence of a Hermitian solution to this equation by using a newly defined real representation method. Furthermore, we obtain the solutions for the dual split quaternion matrix equations A X   =   C and X B   =   C . Finally, we provide a numerical example to demonstrate the findings of this paper. [ABSTRACT FROM AUTHOR]

The notion of a transposed Poisson n -Lie algebra has been developed as a natural generalization of a transposed Poisson algebra. It was conjectured that a transposed Poisson n -Lie algebra with a derivation gives rise to a transposed Poisson (n + 1) -Lie algebra. In this paper, we focus on transposed Poisson n -Lie algebras. We have obtained a rich family of identities for these algebras. As an application of these formulas, we provide a construction of (n + 1) -Lie algebras from transposed Poisson n -Lie algebras with derivations under a certain strong condition, and we prove the conjecture in these cases. The notion of a transposed Poisson -Lie algebra has been developed as a natural generalization of a transposed Poisson algebra. It was conjectured that a transposed Poisson -Lie algebra with a derivation gives rise to a transposed Poisson -Lie algebra. In this paper, we focus on transposed Poisson -Lie algebras. We have obtained a rich family of identities for these algebras. As an application of these formulas, we provide a construction of -Lie algebras from transposed Poisson -Lie algebras with derivations under a certain strong condition, and we prove the conjecture in these cases. [ABSTRACT FROM AUTHOR]

In this paper, we introduce the concept and representations of modified λ-differential Hom-Lie algebras. We then develop the cohomology of modified λ-differential Hom-Lie algebras with coefficients in a suitable representation. As applications, abelian extensions and skeletal modified λ-differential Hom-Lie 2-algebras are characterized in terms of cohomology groups. [ABSTRACT FROM AUTHOR]

In this paper, we introduce the concept of a Quasi B-algebra, building upon the foundational work on Post algebras by G. Epstein and the investigation of semi B-algebras. We systematically explore the properties of Quasi B-algebras, establishing equivalent conditions for the transition from a semi B-algebra to a Quasi B-algebra. [ABSTRACT FROM AUTHOR]

This is a noticeably short biography and introductory paper on multiplier Hopf algebras. It delves into questions regarding the significance of this abstract construction and the motivation behind its creation. It also concerns quantum linear groups, especially the coordinate ring of Mq(n) and the observation that K [Mq(n)] is a quadratic algebra, and can be equipped with a multiplier Hopf ∗-algebra structure in the sense of quantum permutation groups developed byWang and an observation by Rollier–Vaes. In our next paper, we will propose the study of multiplier Hopf graph algebras. The current paper can be viewed as a precursor to this upcoming work, serving as a crucial intermediary bridging the gap between the abstract concept of multiplier Hopf algebras and the well-developed field of graph theory, thereby establishing connections between them! This survey review paper is dedicated to the 78th birthday anniversary of Professor Alfons Van Daele. [ABSTRACT FROM AUTHOR]

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Let K be a field and S = K[x1,..., xn] a standard polynomial ring over K. In this paper, we give new combinatorial algorithms to compute the smallest t-spread lexicographic set and the smallest t-spread strongly stable set containing a given set of t-spread monomials of S. Some technical tools allowing to compute the cardinality of t-spread strongly stable sets avoiding their construction are also presented. Such functions are also implemented in a Macaulay2 package, TSpreadIdeals, to ease the computation of well-known results about algebraic invariants for t-spread ideals. [ABSTRACT FROM AUTHOR]

Let D be a strongly double triangle subspace lattice on a nonzero complex reflexive Banach space. In this paper, we characterize the linear maps δ, τ: AlgD → AlgD satisfying δ(A)B+ Aτ(B) = 0 for any A, B ∈ AlgD with AB = 0. This result can be used to characterize linear maps derivable (centralized) at zero point and local centralizers on AlgD, respectively. [ABSTRACT FROM AUTHOR]

This paper proposes a systematic method for the identification of the load circuit parameters (say the $\boldsymbol{R}$ , $\boldsymbol{L}$ , and $\boldsymbol{C}$ elements) based only on the information of the instantaneous voltage and current measured at the point of common coupling (pcc). Geometric Algebra (GA) and concepts of differential geometry are used to produce a rigorous mathematical framework. The identification is formulated as a multidimensional geometrical problem that is solved conveniently by means of GA. Once the passive elements of the load have been identified, the active and reactive powers can be computed from first electromagnetic principles (Maxwell Equations). The theory is general and is verified with linear and nonlinear circuits. The paper shows single-phase circuits but the theory can be extended to three-phase circuits. The method is easy to program and has shown to be very robust for all tested cases. Because of its generality, the method presented will find applications beyond electric circuits. [ABSTRACT FROM AUTHOR]

Important connections in representation theory arise from resolving a finite-dimensional algebra by an endomorphism algebra of a generator-cogenerator with finite global dimension; for instance, Auslander's correspondence, classical Schur–Weyl duality and Soergel's Struktursatz. Here, the module category of the resolution and the module category of the algebra being resolved are linked via an exact functor known as the Schur functor. In this paper, we investigate how to measure the quality of the connection between module categories of (projective) Noetherian algebras, B, and module categories of endomorphism algebras of generator-relative cogenerators over B which are split quasi-hereditary Noetherian algebras. In particular, we are interested in finding, if it exists, the highest degree n so that the endomorphism algebra of a generator-cogenerator provides an n-faithful cover, in the sense of Rouquier, of B. The degree n is known as the Hemmer–Nakano dimension of the standard modules. We prove that, in general, the Hemmer–Nakano dimension of standard modules with respect to a Schur functor from a split highest weight category over a field to the module category of a finite-dimensional algebra B is bounded above by the number of non-isomorphic simple modules of B. We establish methods for reducing computations of Hemmer–Nakano dimensions in the integral setup to computations of Hemmer–Nakano dimensions over finite-dimensional algebras, and vice-versa. In addition, we extend the framework to study Hemmer–Nakano dimensions of arbitrary resolving subcategories. In this setup, we find that the relative dominant dimension over (projective) Noetherian algebras is an important tool in the computation of these degrees, extending the previous work of Fang and Koenig. In particular, this theory allows us to derive results for Schur algebras and the BGG category \mathcal {O} in the integral setup from the finite-dimensional case. More precisely, we use the relative dominant dimension of Schur algebras to completely determine the Hemmer–Nakano dimension of standard modules with respect to Schur functors between module categories of Schur algebras over regular Noetherian rings and module categories of group algebras of symmetric groups over regular Noetherian rings. We exhibit several structural properties of deformations of the blocks of the Bernstein-Gelfand-Gelfand category \mathcal {O} establishing an integral version of Soergel's Struktursatz. We show that deformations of the combinatorial Soergel's functor have better homological properties than the classical one. [ABSTRACT FROM AUTHOR]

In this paper, we make use of the simultaneous decomposition of eight quaternion matrices to study the solvability conditions and general solutions to a system of two-sided coupled Sylvester-type quaternion matrix equations A i X i C i + B i X i + 1 D i = Ω i , i = 1 , 2 , 3 , 4. We design an algorithm to compute the general solution to the system and give a numerical example. Additionally, we consider the application of the system in the encryption and decryption of color images. [ABSTRACT FROM AUTHOR]

Let A be a unital A-algebra containing a non-trivial projection. In this paper, we prove that if a map Ω: A → A such that Ω([K, F]A ⊙ D) = [Ω(K), F]A ⊙ D + [K, Ω(F)]A ⊙ D + [K, F]A ⊙ Ω(D), where [K, F]A = KF - FKA and K ⊙ F = KAF + FKA for all K, F, D ∈ A, then Ω is an additive A-derivation. Furthermore, we extend its results on factor von Neumann algebras, standard operator algebras and prime A-algebras. Additionally, we provide an example illustrating the existence of such maps. [ABSTRACT FROM AUTHOR]

The goal of the present paper is to provide a cohomology theory and crossed modules of modified Rota–Baxter pre-Lie algebras. We introduce the notion of a modified Rota–Baxter pre-Lie algebra and its bimodule. We define a cohomology of modified Rota–Baxter pre-Lie algebras with coefficients in a suitable bimodule. Furthermore, we study the infinitesimal deformations and abelian extensions of modified Rota–Baxter pre-Lie algebras and relate them with the second cohomology groups. Finally, we investigate skeletal and strict modified Rota–Baxter pre-Lie 2-algebras. We show that skeletal modified Rota–Baxter pre-Lie 2-algebras can be classified into the third cohomology group, and strict modified Rota–Baxter pre-Lie 2-algebras are equivalent to the crossed modules of modified Rota–Baxter pre-Lie algebras. [ABSTRACT FROM AUTHOR]

Quantum groups occupy a significant position in both mathematics and physics, contributing to progress in these fields. It is interesting to obtain new quantum groups by the quantization of Lie bialgebras. In this paper, the quantization of the rank two Heisenberg–Virasoro algebra by Drinfel'd twists is presented, Lie bialgebra structures of which have been investigated by the authors recently. [ABSTRACT FROM AUTHOR]

In this paper, we give another definition of Ruston elements and almost Ruston elements, which is equivalent to the definitions given by Mouton and Raubenheimer in the case that the homomorphism has a closed range and Riesz property. For two homomorphisms, we consider the preserver problems of Fredholm theory and Fredholm spectrum theory. In addition, we study the spectral mapping theorems of Fredholm (Weyl, Browder, Ruston, and almost Ruston) elements relative to a homomorphism. Last but not least, the dependence of Fredholm theory on three homomorphisms is considered, and meanwhile, the transitivity of Fredholm theory relative to three homomorphisms is illustrated. Furthermore, we consider the Fredholm theory relative to more homomorphisms. [ABSTRACT FROM AUTHOR]

In this paper, we introduce and study the concept of hyper-instability as a strong version of multiplicative instability. This concept provides a powerful tool to study the multiplicative instability of Banach algebras. It replaces the condition of the iterated limits in the definition of multiplicative instability with conditions that are easier to examine. In particular, special conditions are suggested for Banach algebras that admit bounded approximate identities. Moreover, these conditions are preserved under isomorphisms. This enlarges the class of studied Banach algebras. We prove that many interesting Banach algebras are hyper-unstable, such as C-algebras, Fourier algebras, and the algebra of compact operators on Banach spaces, each under certain conditions. [ABSTRACT FROM AUTHOR]

Convolution plays a pivotal role in the domains of signal processing and optics. This paper primarily focuses on studying the weighted convolution for quaternion linear canonical cosine transform (QLCcT) and its application in multiplicative filter analysis. Firstly, we propose QLCcT by combining quaternion algebra with linear canonical cosine transform (LCcT), which extends LCcT to Hamiltonian quaternion algebra. Secondly, we introduce weighted convolution and correlation operations for QLCcT, accompanied by their corresponding theorems. We also explore the properties of QLCcT. Thirdly, we utilize these proposed convolution structures to analyze multiplicative filter models that offer lower computational complexity compared to existing methods based on quaternion linear canonical transform (QLCT). Additionally, we discuss the rationale behind studying such transforms using quaternion functions as an illustrative example. [ABSTRACT FROM AUTHOR]

One of the most relevant topics in web theory is linearization. A particular class of linearizable webs is the Grassmannizable web. Akivis gave a characterization of such a web, showing that Grassmannizable webs are equivalent to isoclinic and transversally geodesic webs. The obstructions given by Akivis that characterize isoclinic and transversally geodesic webs are computed locally, and it is difficult to give them an interpretation in relation to torsion or curvature of the unique Chern connection associated with a web. In this paper, using Nagy's web formalism, Frölisher—Nejenhuis theory for derivation associated with vector differential forms, and Grifone's connection theory for tensorial algebra on the tangent bundle, we find invariants associated with almost-Grassmann structures expressed in terms of torsion, curvature, and Nagy's tensors, and we provide an interpretation in terms of these invariants for the isoclinic, transversally geodesic, Grassmannizable, and parallelizable webs. [ABSTRACT FROM AUTHOR]

In this paper, we define a cohomology theory of a modified λ -differential left-symmetric algebra. Moreover, we introduce the notion of modified λ -differential left-symmetric 2-algebras, which is the categorization of a modified λ -differential left-symmetric algebra. As applications of cohomology, we classify linear deformations and abelian extensions of modified λ -differential left-symmetric algebras using the second cohomology group and classify skeletal modified λ -differential left-symmetric 2-algebra using the third cohomology group. Finally, we show that strict modified λ -differential left-symmetric 2-algebras are equivalent to crossed modules of modified λ -differential left-symmetric algebras. [ABSTRACT FROM AUTHOR]

In this paper, we provide some properties of k-potent elements in algebras obtained by the Cayley–Dickson process over Z p . Moreover, we find a structure of nonunitary ring over Fibonacci quaternions over Z 3 and we present a method to encrypt plain texts, by using invertible elements in some of these algebras. [ABSTRACT FROM AUTHOR]

In this paper we investigate left ideals as codes in twisted skew group rings. The considered rings, which are in most cases algebras over a finite field, allow us to retrieve many of the well-known codes. The presentation, given here, unifies the concept of group codes, twisted group codes and skew group codes. [ABSTRACT FROM AUTHOR]

In this paper, by using the notion of fuzzy points and equality algebras, the notions of fuzzy point equality algebra, equality-subalgebra, and ideal were established. Some characterizations of fuzzy subalgebras were provided by using such concepts. We defined the concepts of (∈, ∈) and (∈, ∈ ∨ q)-fuzzy ideals of equality algebras, discussed some properties, and found some equivalent definitions of them. In addition, we investigated the relation between different kinds of (α, β)-fuzzy subalgebras and (α, β)-fuzzy ideals on equality algebras. Also, by using the notion of (∈, ∈)-fuzzy ideal, we defined two equivalence relations on equality algebras and we introduced an order on classes of X, and we proved that the set of all classes of X by these order is a poset. [ABSTRACT FROM AUTHOR]

In this paper, we construct a symbol calculus yielding short exact sequences for the dual Toeplitz algebra generated by all bounded dual Toeplitz operators on the Hardy space associated with the polydisk D n in the unitary space C n , that have been introduced and well studied in our earlier paper (Benaissa and Guediri in Taiwan J Math 19: 31–49, 2015), as well as for the C*-subalgebra generated by dual Toeplitz operators with symbols continuous on the associated hypertorus T n . [ABSTRACT FROM AUTHOR]