4,130 results
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2. Kindergarten children's symbolic number comparison skills relates to 1st grade mathematics achievement: Evidence from a two-minute paper-and-pencil test.
- Author
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Hawes, Zachary, Archibald, Lisa, Ansari, Daniel, and Nosworthy, Nadia
- Subjects
- *
MATHEMATICS , *MATHEMATICAL ability in children , *MATHEMATICAL ability testing , *LONGITUDINAL method , *SYMBOLISM of numbers , *ARITHMETIC , *KINDERGARTEN , *CHILDREN - Abstract
Abstract Basic numerical skills provide an important foundation for the learning of mathematics. Thus, it is critical that researchers and educators have access to valid and reliable ways of assessing young children's numerical skills. The purpose of this study was to evaluate the concurrent, predictive, and incremental validity of a two-minute paper-and-pencil measure of children's symbolic (Arabic numerals) and non-symbolic (dot arrays) comparison skills. A sample of kindergarten children (M age = 5.86, N = 439) were assessed on the measure along with a number line estimation task, a measure of arithmetic, and several control measures. Results indicated that performance on the symbolic comparison task explained unique variance in children's arithmetic performance in kindergarten. Longitudinal analyses demonstrated that both symbolic comparison and number line estimation in kindergarten were independent predictors of 1st grade mathematics achievement. However, only symbolic comparison remained a unique predictor once language skills and processing speed were taken into account. These results suggest that a two-minute paper-and-pencil measure of children's symbolic number comparison is a reliable predictor of children's early mathematics performance. Highlights • We tested the validity and reliability of a recently developed Numeracy Screener. • Performance on the symbolic comparison task predicted kindergarten children's arithmetic performance. • Performance on the symbolic comparison task in kindergarten predicted school mathematics achievement one year later. • The Numeracy Screener may be a useful tool for early mathematics researchers and educators alike. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
3. Invited paper: estimation of motion from a pair of range images: a review
- Author
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Sabata, Bikash and Aggarwal, J.K.
- Subjects
Dynamics ,Analysis ,Machine Vision ,Mathematics ,Methods ,Image Motion ,Time and Motion Study - Published
- 1991
4. Some remarks on pragmatics in the language of mathematics: Comments to the paper "At Least One Black Sheep: Pragmatics and Mathematical Language" by Luca San Mauro, Marco Ruffino and Giorgio Venturi.
- Author
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Ranta, Aarne
- Subjects
- *
PRAGMATICS , *MATHEMATICS , *LANGUAGE & languages - Abstract
I agree wholeheartedly with the authors of "At Least One Black Sheep: Pragmatics and Mathematical Language" on their main thesis that the language of mathematics is permeated by phenomena that belong to pragmatics. I also agree with what they take to be the opposite view, which is presented in Mohan Ganesalingam's monograph The Language of Mathematics (2013). I think that the conflict is to a large extent terminological and has to do with what is meant by pragmatics. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
5. Another modification from two papers of Ghodousian and Khorram and Khorram et al.
- Author
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Abbasi Molai, Ali and Khorram, Esmaile
- Subjects
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MATHEMATICS , *ALGORITHMS , *MATHEMATICAL optimization , *LINEAR programming - Abstract
Abstract: In this paper, we focus on the proposed algorithms to solve a linear programming problem with the convex combination of the max–min and the max–average composition and the max–star composition, respectively. They have been proposed by Ghodousian and Khorram [A. Ghodousian, E. Khorram, Solving a linear programming problem with the convex combination of the max–min and the max–average fuzzy relation equations, Appl. Math. Comput. 180 (2006) 411–418] and Khorram et al. [E. Khorram, A. Ghodousian, A. Abbasi Molai, Solving linear optimization problems with max–star composition equation constraints, Appl. Math. Comput. 179 (2006) 654–661], respectively. Firstly, we show that the “Tabular method algorithm” in the first paper and the “First procedure” in the second paper may not lead to the optimal solutions of the two models in some cases. Secondly, we generalize the proposed algorithm by Abbasi Molai and Khorram [A. Abbasi Molai, E. Khorram, A modified algorithm for solving the proposed models by Ghodousian and Khorram and Khorram and Ghodousian, Appl. Math. Comput. 190 (2007) 1161–1167] to solve the two models. In fact, it modifies the presented algorithms in the two papers. Finally, some numerical examples are given to illustrate the purposes. [Copyright &y& Elsevier]
- Published
- 2008
- Full Text
- View/download PDF
6. Some remarks on Arslan’s 2011 paper
- Author
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Hamedani, G.G. and Volkmer, Hans W.
- Subjects
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KOLMOGOROV complexity , *MATHEMATICAL proofs , *MATHEMATICS , *ELECTRONIC data processing , *PROOF theory , *INFORMATION theory - Abstract
Abstract: It is shown that the main theorem of Arslan’s paper (Theorem 2, 2011), as stated, is incorrect. Under additional conditions, we present a short proof of the corrected version of the theorem. We also give a proof of a theorem of Rao and Shanbhag (1991) , employed by Arslan, without the use of the Kolmogorov Consistency Theorem. [Copyright &y& Elsevier]
- Published
- 2013
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7. How does building arguments relate to the development of understanding?: A response to the last three papers
- Author
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Speiser, Bob
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MATHEMATICS , *DEBATE - Abstract
In mathematics, for professionals, the most compelling way to back a statement is to prove it. This could even be true, as recent research indicates, for 9-year-olds (or for even younger learners), given appropriate conditions in the early grades. In this article, based on data drawn from the three preceding papers, I explore some ways in which the building of an argument can emerge in step with the development of understanding. [Copyright &y& Elsevier]
- Published
- 2002
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8. A correction to the paper “On minima of radially symmetric functionals of the gradient”
- Author
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Cellina, A. and Perrotta, S.
- Subjects
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NONLINEAR statistical models , *MATHEMATICAL models , *MATHEMATICS , *SIMULATION methods & models - Abstract
Abstract: We prove a theorem for the existence of solutions to a variational problem, under assumptions that do not require the convexity of the integrand. [Copyright &y& Elsevier]
- Published
- 2008
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9. Some remarks on a paper by L. Carlitz
- Author
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Dominici, Diego
- Subjects
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POLYNOMIALS , *ALGEBRA , *MATHEMATICS , *MATHEMATICAL analysis - Abstract
Abstract: We study a family of orthogonal polynomials which generalizes a sequence of polynomials considered by L. Carlitz. We show that they are a special case of the Sheffer polynomials and point out some interesting connections with certain Sobolev orthogonal polynomials. [Copyright &y& Elsevier]
- Published
- 2007
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10. Some sixth-order variants of Ostrowski root-finding methods
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Chun, Changbum and Ham, YoonMee
- Subjects
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PAPER , *EQUATIONS , *ALGEBRA , *MATHEMATICS - Abstract
Abstract: In this paper, we present some sixth-order class of modified Ostrowski’s methods for solving nonlinear equations. Per iteration each class member requires three function and one first derivative evaluations, and is shown to be at least sixth-order convergent. Several numerical examples are given to illustrate the performance of some of the presented methods. [Copyright &y& Elsevier]
- Published
- 2007
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11. A game-theoretic implication of the Riemann hypothesis.
- Author
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Ewerhart, Christian
- Subjects
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RIEMANN hypothesis , *NASH equilibrium , *PLEONASM , *MATHEMATICS - Abstract
The Riemann hypothesis (RH) is one of the major unsolved problems in pure mathematics. In the present paper, a parameterized family of non-cooperative games is constructed with the property that, if RH is true, then any game in the family admits a unique Nash equilibrium. We argue that this result is not degenerate. Indeed, neither is the conclusion a tautology, nor is RH used to define the family of games. • The Riemann Hypothesis (RH) is a famous open problem in mathematics. • This paper constructs generalized difference-form contests related to RH. • These contests admit a unique Nash equilibrium if RH holds true. • We argue that the result is not degenerate in any obvious way. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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12. A note on a paper by Su Ke and He Zhen
- Author
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Liu, Zhenhai and Migórski, Stanisław
- Subjects
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MONOTONE operators , *BANACH spaces , *NONLINEAR evolution equations , *OPERATOR theory , *MATHEMATICS - Abstract
Abstract: In this note we show that a multivalued bounded quasimonotone operator of type between a reflexive Banach space and its dual is pseudomonotone. Hence we deduce that a result of Su Ke and He Zhen [Su Ke, He Zhen, Solutions of nonlinear evolution inclusions, J. Math. Anal. Appl. 313 (2006) 84–97] follows from a theorem of Bian and Webb [W. Bian, J.R.L. Webb, Solutions of nonlinear evolution inclusions, Nonlinear Anal. 37 (1999) 915–932]. [Copyright &y& Elsevier]
- Published
- 2009
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13. A note on a paper by E. Khorram and A. Ghodousian
- Author
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Zimmermann, Karel
- Subjects
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MATHEMATICAL functions , *MATHEMATICAL optimization , *ALGORITHMS , *MATHEMATICS - Abstract
Abstract: The aim of this short note is to show on a numerical example that one of the two optimization algorithms proposed in [E. Khorram, A. Ghodousian, Linear objective function optimization with fuzzy relation equation constraints regarding max-av composition, Appl. Math. Comput. 173 (2006) 872–886] may not lead to the optimal solution in some cases. Besides it will be pointed out that the other algorithm (correct, but unfortunately ineffective for larger problems) proposed in [E. Khorram, A. Ghodousian, Linear objective function optimization with fuzzy relation equation constraints regarding max-av composition, Appl. Math. Comput. 173 (2006) 872–886] can be extended to a wider class of non-convex optimization problems. [Copyright &y& Elsevier]
- Published
- 2007
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14. A note correcting the proof of a lemma in a recent paper
- Author
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Peng, Mingshu
- Subjects
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OSCILLATION theory of differential equations , *LINEAR differential equations , *LINEAR systems , *EQUATIONS , *MATHEMATICS - Abstract
A nonoscillation criterion for a second-order linear difference equation is established correcting a result in [1]. [Copyright &y& Elsevier]
- Published
- 2003
- Full Text
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15. Scalable DPG multigrid solver for Helmholtz problems: A study on convergence.
- Author
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Badger, Jacob, Henneking, Stefan, Petrides, Socratis, and Demkowicz, Leszek
- Subjects
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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
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16. Realization of systems with CCD-based measurements
- Author
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Looze, Douglas P.
- Subjects
- *
MATHEMATICS , *SCIENCE , *PAPER , *CYBERNETICS - Abstract
Abstract: This paper considers systems that have a measurement that is computed from the post-processing of a short duration image. The measurement can be regarded as the integral of a linear function of the state variables of the system. The input to the system is assumed to be generated with a zero-order hold whose sampling frequency is the same as that of the measurement. The paper presents a discrete-time finite dimensional state variable model for such systems. [Copyright &y& Elsevier]
- Published
- 2005
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17. Comment to the paper “Synthesis of myrcene by pyrolysis of β-pinene: Analysis of decomposition reactions” by M.B. Kolicheski et al. [J. Anal. Appl. Pyrol. 80 (2007) 92–100]
- Author
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Stolle, A. and Ondruschka, B.
- Subjects
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CHEMICAL reactions , *MATHEMATICS , *MATHEMATICAL statistics , *REACTION mechanisms (Chemistry) - Abstract
Abstract: The authors presented in their paper a theoretical route describing the formation of myrcene (2) in dependence of the reaction temperature during the production from β-pinene (1) [M.B. Kolicheski, L.C. Cocco, D.A. Mitchell, M. Kaminski, J. Anal. Appl. Pyrol. 80 (2007) 92]. Pyrolysis experiments carried out seem to correlate with the mathematical model. Initial reaction schemes for the formation of 2 as well as for decomposition reactions were presented. However, reconsideration of the data reviled, serious interpretation flaws regarding content and reaction mechanisms were found. [Copyright &y& Elsevier]
- Published
- 2008
- Full Text
- View/download PDF
18. Dual-mode floating-point multiplier architectures with parallel operations
- Author
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Akkaş, Ahmet and Schulte, Michael J.
- Subjects
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READY-reckoners , *HARDWARE , *PAPER testing , *MATHEMATICS - Abstract
Abstract: Although most modern processors have hardware support for double precision or double-extended precision floating-point multiplication, this support is inadequate for many scientific computations. This paper presents the architecture of a quadruple precision floating-point multiplier that also supports two parallel double precision multiplications. Since hardware support for quadruple precision arithmetic is expensive, a new technique is presented that requires much less hardware than a fully parallel quadruple precision multiplier. With this architecture, quadruple precision multiplication has a latency of three cycles and two parallel double precision multiplications have latencies of only two cycles. The multiplier is pipelined so that two double precision multiplications can begin every cycle or a quadruple precision multiplication can begin every other cycle. The technique used for the dual-mode quadruple precision multiplier is also applied to the design of a dual-mode double precision floating-point multiplier that performs a double precision multiplication or two single precision multiplications in parallel. Synthesis results show that the dual-mode double precision multiplier requires 43% less area than a conventional double precision multiplier. The correctness of all the multipliers presented in this paper is tested and verified through extensive simulation. [Copyright &y& Elsevier]
- Published
- 2006
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19. Enveloping monoidal quandles
- Author
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Kamada, Seiichi and Matsumoto, Yukio
- Subjects
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MONODROMY groups , *GROUP theory , *PAPER , *MATHEMATICS - Abstract
A quandle is a set with a self-distributive binary operation satisfying a certain condition. Here we construct a monoid (a semi-group with the identity) associated with a quandle. This monoid has a structure of a quandle, which contains the original quandle as a sub-quandle. We call it the enveloping monoidal quandle. The purpose of this paper is to introduce the notion of the enveloping monoidal quandle, and to investigate it. [Copyright &y& Elsevier]
- Published
- 2005
- Full Text
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20. Distinguished representatives for equivalent labelled stratified graphs and applications
- Author
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Ţăndăreanu, Nicolae
- Subjects
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SET theory , *AGGREGATED data , *PAPER , *MATHEMATICS - Abstract
Abstract: The concept of labelled stratified graph (LSG) was introduced in Ţăndăreanu (Knowledge Inform. Syst. 2(4) (2000) 438) in connection with that of knowledge base with output (KBO). The aim of this paper is to present a distinct facet of this concept. We prove several algebraic properties for LSGs and we conclude that a LSG can be used independently of a KBO. In order to realize this aim we define a partial order on the set of all LSGs over a labelled graph G, an equivalence relation on and a partial order on the factor set. The set endowed with becomes a join semilattice with greatest element. Each equivalence class contains an unique LSG, which is named distinguished representative of C. This is the least element of. Particularly we obtain the distinguished representative for the supremum of two classes (DRS) and the greatest distinguished LSG (the least LSG of the greatest element of, denoted GD). Two applications are presented, one for DRS and one for GD. Several opens problems are briefly exposed in the last section. [Copyright &y& Elsevier]
- Published
- 2004
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21. On the Hurwitz stability of noninteger Hadamard powers of stable polynomials.
- Author
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Białas, Stanisław, Białas-Cież, Leokadia, and Kudra, Michał
- Subjects
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POLYNOMIALS , *MATHEMATICS - Abstract
Consider a polynomial f (z) = a n z n +... + a 1 z + a 0 of positive coefficients that is stable (in the Hurwitz sense), i.e., every root of f lies in the open left half-plane of C. Due to Garloff and Wagner [J. Math. Anal. Appl. 202 (1996)], the p th Hadamard power of f : f [ p ] (z) : = a n p z n +... + a 1 p z + a 0 p is stable if p is a positive integer number. However, it turns out that f [ p ] does not need to be stable for all real p > 1. A counterexample is known for n = 8 and p = 1.139. On the other hand, f [ p ] is stable for n = 1 , 2 , 3 , 4 , and every p > 1. In this paper we fill the gap by showing that f [ p ] is stable for n = 5 and constructing counterexamples for n ≥ 6. Moreover, by means of Rouché's Theorem, we give some stability conditions for polynomials and two examples that complete and illustrate the results. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
22. The matter of math: Guiding the blind to touch the Pythagorean theorem.
- Author
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Due, Brian L.
- Abstract
Science teaching relies heavily on visual illustrations and visually organized assignments as methods of teaching and proving concepts like the Pythagorean theorem. As Visually Impaired Persons (VIPs) cannot see, they derive no benefit from the use of such illustrations alone. Often, material objects are used to help VIPs understand mathematical concepts by means of tactile and haptic perception. In this paper, I will show the practices employed in the pursuit of transforming a visually available material object into something of specific scientific relevance for tactile and haptic exploration. This article thus emphasizes the matter – in the original sense of materiality – of math. Based on video-recorded data, this paper provides an in-depth interactional analysis of a single case in which a VIP engages in a mathematics learning situation with an assistant. This research is based on and contributes to ethnomethodology and conversation analysis by critically examining how objects are used to teach VIPs in math classes. The research has implications for a broadened understanding of how learning mathematics is not just a matter of logics, verbal descriptions or the visual analysis of charts and diagrams, but can also inherently involve the tangible materiality of mathematical representations. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
23. Maxima of the Q-index of non-bipartite C3-free graphs.
- Author
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Liu, Ruifang, Miao, Lu, and Xue, Jie
- Subjects
- *
BIPARTITE graphs , *GRAPH theory , *TRIANGLES , *MATHEMATICS - Abstract
A classic result in extremal graph theory, known as Mantel's theorem, states that every non-bipartite graph of order n with size m > ⌊ n 2 4 ⌋ contains a triangle. Lin, Ning and Wu [Comb. Probab. Comput. 30 (2021) 258-270] proved a spectral version of Mantel's theorem for given order n. Zhai and Shu [Discrete Math. 345 (2022) 112630] investigated a spectral version for fixed size m. In this paper, we prove Q -spectral versions of Mantel's theorem. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
24. Boundedness criteria for a class of indirect (and direct) chemotaxis-consumption models with signal-dependent sensitivity in high dimensions.
- Author
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Chiyo, Yutaro, Sugawara, Kazuma, and Yokota, Tomomi
- Subjects
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CHEMOTAXIS , *MATHEMATICS - Abstract
This paper is concerned with an indirect chemotaxis-consumption model with sensitivity function χ (v). Frassu and Viglialoro (Appl. Math. Lett.; 2022; 132; 108108) showed global existence and boundedness in the case that χ is a constant. However, there is a room for improvement of the main claim. This paper improves the result and extends it in the case that χ depends on v. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
25. On the edge dimension and the fractional edge dimension of graphs.
- Author
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Yi, Eunjeong
- Subjects
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GRAPH connectivity , *PLANAR graphs , *GEODESICS , *GRAPH labelings , *MATHEMATICS - Abstract
Let G be a graph with vertex set V (G) and edge set E (G) , and let d (u , w) denote the length of a u − w geodesic in G. For any vertex v ∈ V (G) and any edge e = x y ∈ E (G) , let d (e , v) = min { d (x , v) , d (y , v) }. For any distinct edges e 1 , e 2 ∈ E (G) , let R { e 1 , e 2 } = { z ∈ V (G) : d (z , e 1) ≠ d (z , e 2) }. Kelenc, Tratnik and Yero [Discrete Appl. Math. 251 (2018) 204-220] introduced the notion of an edge resolving set and the edge dimension of a graph: A vertex subset S ⊆ V (G) is an edge resolving set of G if | S ∩ R { e 1 , e 2 } | ≥ 1 for any distinct edges e 1 , e 2 ∈ E (G) , and the edge dimension , edim (G) , of G is the minimum cardinality among all edge resolving sets of G. For a function g defined on V (G) and for U ⊆ V (G) , let g (U) = ∑ s ∈ U g (s). A real-valued function g : V (G) → [ 0 , 1 ] is an edge resolving function of G if g (R { e 1 , e 2 }) ≥ 1 for any distinct edges e 1 , e 2 ∈ E (G). The fractional edge dimension , edim f (G) , of G is min { g (V (G)) : g is an edge resolving function of G }. Note that edim f (G) reduces to edim (G) if the codomain of edge resolving functions is restricted to { 0 , 1 }. In this paper, we introduce and study the fractional edge dimension of graphs, and we obtain some general results on the edge dimension of graphs. We show that there exist two non-isomorphic graphs on the same vertex set with the same edge metric coordinates. We construct two graphs G and H such that H ⊂ G and both edim (H) − edim (G) and edim f (H) − edim f (G) can be arbitrarily large. We show that a graph G with edim (G) = 2 cannot have K 5 or K 3 , 3 as a subgraph, and we construct a non-planar graph H satisfying edim (H) = 2. It is easy to see that, for any connected graph G of order at least three, 1 ≤ edim f (G) ≤ | V (G) | 2 ; we characterize graphs G satisfying edim f (G) = 1 and examine some graph classes satisfying edim f (G) = | V (G) | 2 . We also determine the fractional edge dimension for some classes of graphs. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
26. Paving the cowpath in research within pure mathematics: A medium level model based on text driven variations.
- Author
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Heuer, Karl and Sarikaya, Deniz
- Subjects
- *
SOFTWARE architecture , *MATHEMATICS , *GRAPH coloring , *ARCHITECTURAL design , *PAVEMENTS - Abstract
In this paper we show how simple text-driven variations of given statements in mathematics can lead to interesting new problems and push forward a whole theory around simple initial questions. We exemplify this in two cases. Case 1 deals with problem-posing activities suitable for pupils and case 2 is a rational reconstruction of the organisation of mathematical knowledge within problems of graph colorings. Mathematicians learn to systematically look for subsequent problems around a given problem. We argue that this toy-model captures a nontrivial part of professional mathematical research within the pure fields and conjecture that it even grasps high level developments in mathematics. By doing this, we implicitly encourage a very simplistic view on criteria, so to speak a "cowpath" approach to progress in mathematics. The term "cowpath" is borrowed from architecture and software design, where it is commonly used. While we can contemplate which pathways are ideal, we may also just plant grass and see where people choose to walk. Those pathways are also self-enforcing, since we are less hesitant to walk on those rather than criss-cross the landscape. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
27. Corrigendum to "Log-concavity of some independence polynomials via a partial ordering" [Discrete Math. 342 (1) (2019) 18–28].
- Author
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Bautista-Ramos, César, Guillén-Galván, Carlos, and Gómez-Salgado, Paulino
- Subjects
- *
POLYNOMIALS , *MATHEMATICS , *DEFINITIONS - Abstract
A flaw in the main definition of the original paper has been corrected. Other typos have been fixed. An error in a lemma proof has been amended. With these changes, all the results in the aforementioned paper are now valid. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
28. Decomposition of planar graphs with forbidden configurations.
- Author
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Li, Lingxi, Lu, Huajing, Wang, Tao, and Zhu, Xuding
- Subjects
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PLANAR graphs , *MATHEMATICS - Abstract
A (d , h) -decomposition of a graph G is an ordered pair (D , H) such that H is a subgraph of G of maximum degree at most h and D is an acyclic orientation of G − E (H) with maximum out-degree at most d. In this paper, we prove that for l ∈ { 5 , 6 , 7 , 8 , 9 } , every planar graph without 4- and l -cycles is (2 , 1) -decomposable. As a consequence, for every planar graph G without 4- and l -cycles, there exists a matching M , such that G − M is 3-DP-colorable and has Alon-Tarsi number at most 3. In particular, G is 1-defective 3-DP-colorable, 1-defective 3-paintable and 1-defective 3-choosable. These strengthen the results in [Discrete Appl. Math. 157 (2) (2009) 433–436] and [Discrete Math. 343 (2020) 111797]. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
29. Structuralism and the conformity of mathematics and nature.
- Author
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Stemeroff, Noah
- Subjects
- *
CALCULUS of variations , *CONFORMITY , *APPLIED mathematics , *STRUCTURALISM , *MATHEMATICS - Abstract
Structuralists typically appeal to some variant of the widely popular 'mapping' account of mathematical representation to suggest that mathematics is applied in modern science to represent the world's physical structure. However, in this paper, I argue that this realist interpretation of the 'mapping' account presupposes that physical systems possess an 'assumed structure' that is at odds with modern physical theory. Through two detailed case studies concerning the use of the differential and variational calculus in modern dynamics, I show that the formal structure that we need to assume in order to apply the mapping account is inconsistent with the way in which mathematics is applied in modern physics. The problem is that a realist interpretation of the 'mapping' account imposes too severe of a constraint on the conformity that must exist between mathematics and nature in order for mathematics to represent the structure of a physical system. • This paper presents a critique of the 'mapping' account of mathematical representation. • The 'mapping' account requires that physical systems possess an assumed structure. • This structure is at odds with modern physical theory. • I argue that a realist interpretation of the account imposes a severe constraint on the conformity between math and nature. • The argument is defended through two case studies concerning the differential and variational calculus. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
30. Comment on "FPGA realization of fractional order neuron" [Appl. Math. Model. 81 (2020) 372–385].
- Author
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AbdelAty, A.M., Fouda, M.E., and Eltawil, A.M.
- Subjects
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MATHEMATICAL errors , *LAPLACIAN operator , *MATHEMATICS , *NEURONS , *FRACTIONAL calculus , *TRANSFER functions - Abstract
• Corrected transfer functions of Al-Alaoui and Tustin based discretizations of the Laplacian operator are discussed. • The updated MAPLE code that generates the discretized transfer functions is provided. • The corrected bode plots of the discretized transfer functions are illustrated. This paper points out a number of mathematical inaccuracies in the recent paper "FPGA Realization of Fractional Order Neuron" by S.A. Malik and A.H. Mir. The comments in this paper pertain mainly with the errors presented in Section 3 of that paper referencing the discretization of the fractional operator. Proposed corrections to the formulas and figures are presented along with a sample Maple code to verify the results. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
31. Characterizing touchscreen actions in technology-enhanced embodied learning for mathematics instruction in K-12 setting – A systematic review (2010–2023).
- Author
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Yeung, Wing-Leung and Ng, Oi-Lam
- Subjects
- *
ELECTRONIC textbooks , *TOUCH screens , *INTERACTIVE learning , *COGNITIVE styles , *MATHEMATICS , *NUMBER concept , *SCIENCE databases - Abstract
Touchscreen devices have become prominent in a variety of educational contexts due to their use of hands-on and interactive learning styles, and particularly for their direct engagement, rapid orientation, and multi-touch affordances, which textbooks and oral instruction may not always provide. As such, over the past decade, both the number of touchscreen applications for mathematics learning and the body of research examining their efficacy have increased. Yet, there are still few existing systematic reviews of how these touchscreen-based mathematics applications promote K-12 student learning. In response, this paper provides an in-depth examination of extant studies which adopt practices that utilize touchscreen technology for K-12 mathematics teaching and learning. The Web of Science database was searched for research published between 2010 and 2023, and 34 papers were chosen to review the empirical bases of touchscreen-based mathematics learning. These articles were analyzed based on the educational contexts found, touchscreen actions prompted, and the mathematical meanings elicited from these actions. Most significantly, we propose a touchscreen action matrix that characterizes the actions performed on the touchscreen platform and presents the mathematical meanings derived from these action categories. We hope that this review and characterization provide guidance for researchers, designers, and educators in eliciting mathematical knowing with action-based design in touchscreen medium. • 34 studies of touchscreen-based mathematics applications are systematically reviewed. • Most apps target number concepts via gamified environments at the early primary level. • We proposed a 2 × 2 touchscreen action matrix to characterize actions on touchscreens. • Number of Input, Temporality, Spatiality & Speed are the four dimensions of interest. • We present findings of how mathematical meanings are elicited from touch taxonomies. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
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32. A scoping review of research into mathematics classroom practices and affect.
- Author
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Murphy, Steve and Ingram, Naomi
- Subjects
- *
MATHEMATICS , *CLASSROOMS , *STUDENT engagement , *MOTIVATION (Psychology) , *STUDENTS - Abstract
Despite much research exploring affect within a mathematics context, poor student engagement in mathematics persists internationally. There is limited research examining mathematics classroom practice and students' affect, with the potential to inform teachers' practice. This scoping review analysed this limited literature. Of 250 papers analysed, only 26 papers adequately described classroom practices, considered students' affective state in response to the practice, and considered mathematics learning outcomes. Collectively, these explore very few of the practices used in mathematics classrooms, highlighting the need for more and improved practice-focussed research to better inform efforts to improve student engagement in mathematics. • Despite extensive mathematics affect research the problem of poor student engagement in mathematics persists internationally. • This scoping review demonstrates there is limited research examining classroom practices, affect and mathematics outcomes. • Improved focus on classroom practice in research examining mathematics and affect is required. • The explanatory model presented describes the interaction of students' affect, classroom practices, and mathematical learning. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
33. Fuzzy closure relations.
- Author
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Ojeda-Hernández, Manuel, Cabrera, Inma P., Cordero, Pablo, and Muñoz-Velasco, Emilio
- Subjects
- *
FUZZY systems , *FUZZY logic , *MATHEMATICS - Abstract
The concept of closure operator is key in several branches of mathematics. In this paper, closure operators are extended to relational structures, more specifically to fuzzy relations in the framework of complete fuzzy lattices. The core of the work is the search for a suitable definition of (strong) fuzzy closure relation, that is, a fuzzy relation whose relation with fuzzy closure systems is one-to-one. The study of the properties of fuzzy closure systems and fuzzy relations helps narrow down this exploration until an appropriate definition is settled. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
34. Approximation methods with inertial term for large-scale nonlinear monotone equations.
- Author
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Ibrahim, A.H., Kumam, P., Rapajić, S., Papp, Z., and Abubakar, A.B.
- Subjects
- *
MATHEMATICS - Abstract
In recent years, systems of nonlinear equations have attracted widespread attention and have been extensively studied. The recent designed Fletcher-Reeves (FR) type methods of Papp and Rapajić [Appl. Math. Comput. 269 (2015) 816–823] [27] are efficient in solving large-scale monotone nonlinear equations due to the simple iterative form. In this paper, we propose an accelerated variant of these FR-type methods for approximating the solutions of nonlinear equations involving monotone and Lipschitz continuous mappings. Under suitable assumptions, we prove that the sequence generated by the new algorithm converges globally. Some numerical results are reported to illustrate the computational performance of the new methods. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
35. Ability grouping in contests
- Author
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Xiao, Jun
- Subjects
Economics ,Mathematics - Abstract
Keywords All-pay; Contest; Mixing; Tracking Abstract This paper considers a planner who can group participants into different competitions for performance ranking and design prize structure in each competition in order to maximize the weighted total performance subject to a positive performance requirement. There are possible spillovers in each competition, because a participant may benefit from others' performance in the same competition. We show that, whatever the type-specific weights are, separating -- assigning participants with the same ability together -- is superior to mixing -- assigning participants with different abilities together. Moreover, we also characterize the associated optimal prize structures. Author Affiliation: Department of Economics, University of Melbourne, Australia Article History: Received 7 December 2021; Revised 17 September 2022; Accepted 8 November 2022 (miscellaneous) Manuscript handled by Editor Andrés Carvajal (footnote)[white star] The author would like to thank Vijay Krishna and John Morgan for encouragement and comments on the early drafts. The comments from Associate Editor Jörg Franke and three referees helped to improve the paper's content and exposition. Financial support from the University of Melbourne is greatly appreciated. Byline: Jun Xiao [jun.xiao@unimelb.edu.au]
- Published
- 2023
- Full Text
- View/download PDF
36. Exact and heuristic solution approaches for the bid construction problem in transportation procurement auctions with a heterogeneous fleet.
- Author
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Hammami, Farouk, Rekik, Monia, and Coelho, Leandro C.
- Subjects
- *
HEURISTIC , *TRANSPORTATION , *MATHEMATICS , *TRUCKLOAD shipping , *ARCHITECTURE - Abstract
• The first paper to address the bid construction problem with heterogeneous fleet. • An efficient MIP formulation with symmetry-breaking constraints. • Exact and heuristic approaches based on adaptive large neighborhood search. • The heuristic provides optimal or near-optimal solutions to benchmark instances. • Instances with up to 500 contracts are solved with a gap lower than 2.53%. This paper solves the bid construction problem (BCP) for heterogeneous truckload operations. Exact and heuristic solution methods are proposed to solve the BCP. The heuristic framework is based on a destroy-repair principle coupled with local search procedures. A heuristic variant integrating a post-optimization method considering solutions obtained during the heuristic search is also proposed. The exact approach uses CPLEX to solve an adapted arc-based mathematical formulation with our best heuristic solution as an initial solution. Computational results show that the proposed methods perform very well in terms of CPU time and solution quality for existing and new sets of instances. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
37. Asymptotical stability and spatial patterns of a spatial cyclic competitive system
- Author
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Gao, Meng and Li, Zizhen
- Subjects
- *
DIFFERENTIAL equations , *LINEAR systems , *NUMERICAL analysis , *MATHEMATICS - Abstract
Abstract: A integro-differential equation (IDE) model of a cyclic competitive system is analyzed. Linear stability analysis are performed about the spatial constant solutions, and conditions are derived under which they are stable or unstable. Spatial patterns along with the instability of the nontrivial equilibrium are also observed. [Copyright &y& Elsevier]
- Published
- 2006
- Full Text
- View/download PDF
38. Fuzzy closure structures as formal concepts.
- Author
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Ojeda-Hernández, Manuel, Cabrera, Inma P., Cordero, Pablo, and Muñoz-Velasco, Emilio
- Subjects
- *
RESIDUATED lattices , *FUZZY systems , *MATHEMATICS , *ORDERED sets - Abstract
Galois connections seem to be ubiquitous in mathematics. They have been used to model solutions for both pure and application-oriented problems. Throughout the paper, the general framework is a complete fuzzy lattice over a complete residuated lattice. The existence of three fuzzy Galois connections (two antitone and one isotone) between three specific ordered sets is proved in this paper. The most interesting part is that fuzzy closure systems, fuzzy closure operators and strong fuzzy closure relations are formal concepts of these fuzzy Galois connections. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
39. The set of anti-Gaussian quadrature rules for the optimal set of quadrature rules in Borges' sense.
- Author
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Petrović, Nevena Z., Pranić, Miroslav S., Stanić, Marija P., and Tomović Mladenović, Tatjana V.
- Subjects
- *
GAUSSIAN quadrature formulas , *ORTHOGONAL polynomials , *SENSES , *MATHEMATICS - Abstract
Laurie in [Math. Comp., 65(1996), pp. 739–747] introduced anti-Gaussian quadrature rule, that gives an error equal in magnitude but of opposite sign to that of the corresponding Gaussian quadrature rule. Guided by that idea, in this paper we consider a set of anti-Gaussian quadrature rules for the optimal set of quadrature rules in Borges' sense (see [Numer. Math., 67(1994), pp. 271–288]), as well as the corresponding class of multiple orthogonal polynomials. The main properties of such quadrature rules and multiple orthogonal polynomials are proved and numerical methods for their constructions are presented. Some numerical examples are also included. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
40. Complete signed graphs with largest maximum or smallest minimum eigenvalue.
- Author
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Ghorbani, Ebrahim and Majidi, Arezoo
- Subjects
- *
EIGENVALUES , *REGULAR graphs , *COMPLETE graphs , *MATHEMATICS - Abstract
In this paper, we deal with extremal eigenvalues of the adjacency matrices of complete signed graphs. The complete signed graphs with maximal index (i.e. the largest eigenvalue) with n vertices and m ≤ ⌊ n 2 / 4 ⌋ negative edges have been already determined. We address the remaining case by characterizing those with m > ⌊ n 2 / 4 ⌋ negative edges. We also identify the unique signed graph with maximal index among complete signed graphs whose negative edges induce a tree of diameter at least d for any given d. This extends a recent result by Li, Lin, and Meng [Discrete Math. 346 (2023), 113250] who established the same result for d = 2. Finally, we prove that the smallest minimum eigenvalue of complete signed graphs with n vertices whose negative edges induce a tree is − n 2 − 1 − 1 + O (1 n). [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
41. Conceptualizing reasoning practices in the context of sociomathematical issues.
- Author
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Chorney, Sean, Evans, Kyle R., and Staples, Megan
- Subjects
- *
MATHEMATICS education , *SOCIAL context , *MATHEMATICS , *APPROXIMATE reasoning , *FAIRNESS - Abstract
In this conceptual paper, we explore a framework of reasoning practices for decision-making in context. We extend prior work related to socioscientific issues (SSI) (Sadler et al., 2007) to consider the applicability of this framework to sociomathematical issues, specifically using the context of fairness in political (re)districting. We illustrate the usefulness of the SSI framework for sociomathematical issues drawing on student work and reflections from two undergraduate courses. We conclude by suggesting adjustments to reasoning practices of the SSI framework that might uniquely reflect the nature of sociomathematical reasoning. We discuss implications of our findings for conceptualizing reasoning practices that include mathematical perspectives within social and political contexts and for mathematics education generally. • Reasoning about a societal issue consists of intertwining personal, practical, contextual, and mathematical meaning. • A framework based on Sadler, Barab & Scott's (2007) analysis of reasoning practices regarding socioscientific issues is useful for analyzing emergent student reasoning in the context of redistricting, a sociomathematical issue. • Students reason in multiple, sophisticated ways about the fairness of specific maps and redistricting processes. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
42. An exploratory mixed methods study about teacher candidates' descriptions of children's confusion, productive struggle, and mistakes in an elementary mathematics methods course.
- Author
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Kalinec-Craig, Crystal and Rios, Anthony
- Subjects
- *
STUDENT teachers , *LEARNING , *TEACHER education , *PARENT-teacher conferences , *SENTIMENT analysis , *MATHEMATICS - Abstract
Recognizing and describing children's mathematical thinking in humanizing ways, especially when students engage in confusion, productive struggle, and mistakes, is a complex and challenging process. This paper describes an exploratory, mixed-methods study about how elementary teacher candidates (TCs) describe children's thinking as a right to exercise and to value their humanity when learning mathematics. The study analyzed transcripts from 64 TCs' summative assessments, which consisted of mock parent-teacher conferences (MPTC). Findings suggest that TCs described children's confusion, productive struggle, and mistakes (RotL 1 and 2) as: a teacher's observation, an opportunity for students to correct or clarify their thinking, an opportunity for teachers to adjust instruction or provide support, and as a normal part of the learning process. More importantly, some TCs reassured children that learners have fundamental rights when learning mathematics, especially when feeling confused and claiming a mistake. Implications for research and teacher education are discussed. Keywords: Elementary, teacher education, mathematics, mixed methods, rehumanizing, Torres' rights of the learner • Topic modeling and sentiment analysis helps to quantify and describe valence that arises from large amounts of text. • 32 TCs identified children's confusion, generalized struggle, and mistakes (Torres' RotL 1 and 2) in their MPTC across 50 instances. • Some TCs described children's confusion and mistakes as rights to exercise, a potential rehumanizing stance. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
43. User-preference based decomposition in MOEA/D without using an ideal point.
- Author
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Qi, Yutao, Li, Xiaodong, Yu, Jusheng, and Miao, Qiguang
- Subjects
MATHEMATICAL optimization ,ALGORITHMS ,MATHEMATICAL analysis ,OPERATIONS research ,MATHEMATICS - Abstract
Abstract This paper proposes a novel decomposition method based on user-preference and developed a variation of the decomposition based multi-objective optimization algorithm (MOEA/D) targeting only solutions in a small region of the Pareto-front defined by the preference information supplied by the decision maker (DM). This is particularly advantageous for solving multi-objective optimization problems (MOPs) with more than 3 objectives, i.e., many-objective optimization problems (MaOPs). As the number of objectives increases, the ability of an EMO algorithm to approximate the entire Pareto front (PF) is rapidly diminishing. In this paper, we first propose a novel scalarizing function making use of a series of new reference points derived from a reference point specified by the DM in the preference model. Based on this scalarizing function, we then develop a user-preference-based EMO algorithm, namely R-MOEA/D. One key merit of R-MOEA/D is that it does not rely on an estimation of the ideal point, which may impact significantly the performances of state-of-the-art decomposition based EMO algorithms. Our experimental results on multi-objective and many-objective benchmark problems have shown that R-MOEA/D provides a more direct and efficient search towards the preferred PF region, resulting in competitive performances. In an interactive setting when the DM changes the reference point during optimization, R-MOEA/D has a faster response speed and performance than the compared algorithms, showing its robustness and adaptability to changes of the preference model. Furthermore, the effectiveness of R-MOEA/D is verified on a real-world problem of reservoir flood control operations. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
44. A dynamic multiobjective evolutionary algorithm based on a dynamic evolutionary environment model.
- Author
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Zou, Juan, Li, Qingya, Yang, Shengxiang, Zheng, Jinhua, Peng, Zhou, and Pei, Tingrui
- Subjects
ALGORITHMS ,FOUNDATIONS of arithmetic ,ALGEBRA ,MATHEMATICS ,CLONES (Algebra) - Abstract
Abstract Traditional dynamic multiobjective evolutionary algorithms usually imitate the evolution of nature, maintaining diversity of population through different strategies and making the population track the Pareto optimal solution set efficiently after the environmental change. However, these algorithms neglect the role of the dynamic environment in evolution, leading to the lacking of active guieded search. In this paper, a dynamic multiobjective evolutionary algorithm based on a dynamic evolutionary environment model is proposed (DEE-DMOEA). When the environment has not changed, this algorithm makes use of the evolutionary environment to record the knowledge and information generated in evolution, and in turn, the knowledge and information guide the search. When a change is detected, the algorithm helps the population adapt to the new environment through building a dynamic evolutionary environment model, which enhances the diversity of the population by the guided method, and makes the environment and population evolve simultaneously. In addition, an implementation of the algorithm about the dynamic evolutionary environment model is introduced in this paper. The environment area and the unit area are employed to express the evolutionary environment. Furthermore, the strategies of constraint, facilitation and guidance for the evolution are proposed. Compared with three other state-of-the-art strategies on a series of test problems with linear or nonlinear correlation between design variables, the algorithm has shown its effectiveness for dealing with the dynamic multiobjective problems. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
45. Reduced-order multiple observer for Takagi–Sugeno systems with unknown inputs.
- Author
-
Lungu, Mihai
- Subjects
MULTIVARIABLE control systems ,MATHEMATICAL models ,ALGORITHMS ,MATHEMATICS ,ALGEBRA - Abstract
Abstract The paper discusses a niche area problem — the design of reduced-order multiple observers which can achieve the finite-time state reconstruction for Takagi–Sugeno multiple models with unknown inputs. The new reduced-order multiple observer obtained in this paper is only the second ever designed, the author of this paper continuing his work started one year ago with the introduction of the reduced-order multiple observer concept. The obtaining of the new reduced-order multiple observer is achieved by combining two classical reduced-order observers for linear time-invariant multivariable systems with unknown inputs and a full-order multiple observer for Takagi–Sugeno systems. The main innovative idea behind the design of the reduced-order multiple observer for Takagi–Sugeno systems described by the multiple models is the split of the multiple model into two subsystems: an unknown-input-free subsystem and an unknown-input-depending subsystem. The unknown-input-free subsystem is brought to the form of a standard multiple model and, in this situation, any algorithm to design full-order multiple observers can be used in the design of reduced-order multiple observers. The steps of the design procedure have been summarized and software implemented; then, the validation of the suggested algorithm has been done for two concrete cases associated to the motion of an aircraft during its landing Highlights • Paper discusses a niche area problem-design of reduced-order multiple observers. • The reduced-order observer designed is only the second one ever obtained. • The steps of the design procedure have been summarized and software implemented. • The observer's performances are compared with the ones of other observers. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
46. The Relationship between the School Resources index; Gender; Age and Mathematics Achievement in TIMSS 2019 survey: Multilevel analysis.
- Author
-
Boulifa, Khalid and Kaaouachi, Abdelali
- Subjects
GENDER ,STATISTICAL software ,MULTILEVEL models ,INTEGRATED software ,MATHEMATICS ,ACHIEVEMENT - Abstract
Factors affecting academic achievement were widely analyzed and compared. This paper studies the effect of some context variables, including Gender, Age and School Resources (namely, General School Resources index ?GSR? and Resources for Mathematics Instruction ?RMI?) on the performance in Mathematics of the Moroccan?s fourth-grade students that participated on the TIMSS 2019 survey. The data collection method uses secondary data from this survey. Two statistical software packages are used (R Core Team, 2017 and SPSS 20) to treat data and apply multilevel modeling. The results of this modeling show that the variance explained at the school level is 39.41 [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
47. Existential monadic second order logic of undirected graphs: The Le Bars conjecture is false.
- Author
-
Popova, S.N. and Zhukovskii, M.E.
- Subjects
- *
UNDIRECTED graphs , *GRAPH theory , *GEOMETRIC vertices , *MATHEMATICAL variables , *MATHEMATICS - Abstract
Abstract In 2001, J.-M. Le Bars disproved the zero-one law (that says that every sentence from a certain logic is either true asymptotically almost surely (a.a.s.), or false a.a.s.) for existential monadic second order sentences (EMSO) on undirected graphs. He proved that there exists an EMSO sentence ϕ such that P (G n ⊨ ϕ) does not converge as n → ∞ (here, the probability distribution is uniform over the set of all graphs on the labeled set of vertices { 1 , ... , n }). In the same paper, he conjectured that, for EMSO sentences with 2 first order variables, the zero-one law holds. In this paper, we disprove this conjecture. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
48. Application of lidar and measure correlate predict method in offshore wind resource assessments.
- Author
-
Sharma, Pramod Kumar, Warudkar, Vilas, and Ahmed, Siraj
- Subjects
- *
ANALYTICAL mechanics , *PROBABILITY theory , *SKEPTICISM , *UNCERTAINTY , *MATHEMATICS - Abstract
Abstract Currently, wind data measurement using lidars or other remote sensing instruments are increasing. Lidar measures the wind data over the full wind turbine, but it is not available for a complete period. This paper investigates the application of measure-correlate-predict technique to short-term lidar measurements in order to extrapolate wind shear index. The wind shear exponent from lidar measurements was compared from mast measurements because lidar and mast have a different measurement methodology. The short-term measurement campaign was conducted at Dhanushkodi to analyze the wind data. This paper discussed the application of measure-correlate-predict method to evaluate the performance of the measure-correlate-predict to extrapolate the short term wind shear exponent. A quantitative analysis of the measure-correlate-predict method has been made. The new approach of measuring wind shear exponent using lidar and measure-correlate-predict was used to test the measured data. The six metrics used to evaluate the MCP predictions in the present analysis. The five parameters used to compare the predicted distribution with the actual long-term wind data. The shear measured by lidar over a height range from 10 m to 220 m. Subsequently, the mast data and the MCP method are used to extrapolate the lidar measurement to get the long-term shear exponent. The reference wind data is used by the wind shear exponent from 10 m to 100 m from the met mast. Due to the reduction of error in the wind shear exponent measurement, the uncertainty can sufficiently reduce in the estimation of wind shear exponent. Comparison of the two correlations signifies that the LR method shows in linear relations that have higher intercepts and lower slopes. A difference is found for shear exponent in the range of 0.13–0.28. Highlights • The wind shear exponent from lidar was compared using mast measurement. • The observation from the mast and lidar at Dhanushkodi are used for the comparison. • The measure-correlate-predict technique is applied to provide longer wind statics than the sample period. • The LR method shows the higher intercepts with a difference is found for shear exponent in the range of 0.13–0.28. • The observations show that the LR method result in the best estimates of the normalized biased. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
49. On the existence of a global minimum in inverse parameters identification by Self-Optimizing inverse analysis method.
- Author
-
Yun, Gun Jin and Shang, Shen
- Subjects
- *
INVERSE problems , *PARAMETERS (Statistics) , *PARTIAL differential equations , *MATHEMATICS , *MATHEMATICAL optimization - Abstract
Abstract In this paper, a mathematical proof of the existence of a global minimum of Self-Optim (Self-Optimizing Inverse Analysis Method) cost functional is presented based upon weak-solution theory of partial differential equations. The Self-Optim provides single global minimum rather than having multiple global minima corresponding to unrealistic solutions of the inverse problem. Furthermore, discrete approximation of the inverse problem and computational methods for the cost functional are proposed and the proof is numerically verified. This paper provides a rigorous mathematical foundation for applications of the Self-Optim method to various inverse problems in mechanics. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
50. Set-membership nonlinear regression approach to parameter estimation.
- Author
-
Perić, Nikola D., Paulen, Radoslav, Villanueva, Mario E., and Chachuat, Benoît
- Subjects
- *
NONLINEAR regression , *MATHEMATICS , *GEOMETRY , *REGRESSION analysis , *ALGEBRA - Abstract
Highlights • The paper contributes set-membership regression (SMR), a new approach to nonlinear parameter estimation under measurement uncertainty. • Links between SMR and both guaranteed parameter estimation and classical statistical inference are investigated. • Several approaches to describing tight enclosures of the SMR regions using complete- search methods are developed. • Case studies are presented to illustrate various theoretical and computational aspects of SMR. Abstract This paper introduces set-membership nonlinear regression (SMR), a new approach to nonlinear regression under uncertainty. The problem is to determine the subregion in parameter space enclosing all (global) solutions to a nonlinear regression problem in the presence of bounded uncertainty on the observed variables. Our focus is on nonlinear algebraic models. We investigate the connections of SMR with (i) the classical statistical inference methods, and (ii) the usual set-membership estimation approach where the model predictions are constrained within bounded measurement errors. We also develop a computational framework to describe tight enclosures of the SMR regions using semi-infinite programming and complete-search methods, in the form of likelihood contour and polyhedral enclosures. The case study of a parameter estimation problem in microbial growth is presented to illustrate various theoretical and computational aspects of the SMR approach. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
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