TY  - JOUR
AU  - Barát, János
TI  - On the number of edges in a K5-minor-free graph of given girth
JF  - DISCRETE MATHEMATICS
J2  - DISCRETE MATH
VL  - 347
PY  - 2024
IS  - 7
SP  - 114042
SN  - 0012-365X
DO  - 10.1016/j.disc.2024.114042
UR  - https://m2.mtmt.hu/api/publication/34831192
ID  - 34831192
LA  - English
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Goswami, Angshuman Robin
TI  - Generalizing the concept of bounded variation
JF  - AEQUATIONES MATHEMATICAE
J2  - AEQUATIONES MATH
VL  - 2024
PY  - 2024
SN  - 0001-9054
DO  - 10.1007/s00010-024-01050-8
UR  - https://m2.mtmt.hu/api/publication/34822769
ID  - 34822769
AB  - Let [a,b]\subseteq \mathbb {R} [ a , b ] ⊆ R be a non-empty and non singleton closed interval and P=\{a=x_0<\cdots <x_n=b\} P = { a = x 0 < ⋯ < x n = b } is a partition of it. Then f:I\rightarrow \mathbb {R} f : I → R is said to be a function of r -bounded variation, if the expression \sum \nolimits ^{n}_{i=1}|f(x_i)-f(x_{i-1})|^{r} ∑ i = 1 n | f ( x i ) - f ( x i - 1 ) | r is bounded for all possible partitions like P . One of the main results of the paper deals with the generalization of the classical Jordan decomposition theorem. We establish that for r\in ]0,1] r ∈ ] 0 , 1 ] , a function of r -bounded variation can be written as the difference of two monotone functions. While for r>1 r > 1 , under minimal assumptions such a function can be treated as an approximately monotone function which can be closely approximated by a nondecreasing majorant. We also prove that for 0<r_1<r_2 0 < r 1 < r 2 , the function class of r_1 r 1 -bounded variation is contained in the class of functions satisfying r_2 r 2 -bounded variations. We go through approximately monotone functions and present a possible decomposition for f:I(\subseteq \mathbb {R}_+)\rightarrow \mathbb {R} f : I ( ⊆ R + ) → R satisfying the functional inequality f(x)\le f(x)+(y-x)^{p}\quad (x,y\in I \text{ with } x<y \text{ and } p\in ]0,1[ ). f ( x ) ≤ f ( x ) + ( y - x ) p ( x , y ∈ I with x < y and p ∈ ] 0 , 1 [ ) . A generalized structural study has also been done in that specific section. On the other hand, for \ell [a,b]\ge d ℓ [ a , b ] ≥ d , a function satisfying the following monotonic condition under the given assumption will be termed as d -periodically increasing f(x)\le f(y)\quad \text{ for } \text{ all }\quad x,y\in I\quad \text{ with }\quad y-x\ge d. f ( x ) ≤ f ( y ) for all x , y ∈ I with y - x ≥ d . We establish that in a compact interval any function satisfying d -bounded variation can be decomposed as the difference of a monotone and a d -periodically increasing function. The core details related to past results, motivation, structure of each and every section are thoroughly discussed below.
LA  - English
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Pituk, Mihály
AU  - Stavroulakis, John Ioannis
TI  - Characterization of shadowing for linear autonomous delay differential equations
JF  - CZECHOSLOVAK MATHEMATICAL JOURNAL
J2  - CZECH MATH J
VL  - 2024
PY  - 2024
SP  - 1
EP  - 8
PG  - 8
SN  - 0011-4642
DO  - 10.21136/CMJ.2024.0191-23
UR  - https://m2.mtmt.hu/api/publication/34780182
ID  - 34780182
LA  - English
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Backes, Lucas
AU  - Dragičević, Davor
AU  - Pituk, Mihály
TI  - Shadowing, Hyers–Ulam stability and hyperbolicity for nonautonomous linear delay differential equations
JF  - COMMUNICATIONS IN CONTEMPORARY MATHEMATICS
J2  - COMMUN CONTEMP MATH
VL  - 2024
PY  - 2024
SN  - 0219-1997
DO  - 10.1142/S0219199724500123
UR  - https://m2.mtmt.hu/api/publication/34765170
ID  - 34765170
AB  - It is known that hyperbolic nonautonomous linear delay differential equations in a finite dimensional space are Hyers–Ulam stable and hence shadowable. The converse result is available only in the special case of autonomous and periodic linear delay differential equations with a simple spectrum. In this paper, we prove the converse and hence the equivalence of all three notions in the title for a general class of nonautonomous linear delay differential equations with uniformly bounded coefficients. The importance of the boundedness assumption is shown by an example.
LA  - English
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Gyarmati, László
AU  - Edvy, László
AU  - Mihálykó, Lajos Csaba
AU  - Mihálykóné Orbán, Éva
TI  - Decision support for sports selection based on performance measurement applying the generalized Thurstone method
JF  - INTERNATIONAL JOURNAL OF SPORTS SCIENCE AND COACHING
J2  - INT J SPORT SCI COACHING
PY  - 2024
SN  - 1747-9541
DO  - 10.1177/17479541241240609
UR  - https://m2.mtmt.hu/api/publication/34762107
ID  - 34762107
AB  - In this article, a new complex method is presented that supports decision-making in sports selection. The method consists of two different parts. The first one is the creation of the framework, that is the assessment of the opinions of trainers about the significance of some attributes in special sports. As a result, weights are constructed based on a generalized 7-option Thurstone method. The second part of the process involves assessing athletes’ performance from various perspectives. Finally, the calculated weights are combined with the performance of the athletes. The scores we obtain quantifiably indicate which sport is most likely to be recommended for a given individual. Moreover, the method developed allows us to quantifiably measure the strength of individual athletes and compare them across age groups equally. A computer program has been developed that implements the evaluation process in addition to this the evaluation results are also presented in this article. By extending this method, it can not only be used for sports selection but also for making various complex decisions where there are numerous possible outcomes to choose from. As a result of this research, we present a generalized set of criteria for the evaluation and describe the results obtained with the method. We explain the relationship between coaching decisions and the recommendations of the method and provide a method for determining the direction of future development for individual athletes.
LA  - English
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Kosztyán, Zsolt Tibor
AU  - Harta, Péter
AU  - Szalkai, István
TI  - The effect of autonomous team role selection in flexible projects
JF  - COMPUTERS AND INDUSTRIAL ENGINEERING
J2  - COMPUT IND ENG
VL  - 190
PY  - 2024
SP  - 110079
SN  - 0360-8352
DO  - 10.1016/j.cie.2024.110079
UR  - https://m2.mtmt.hu/api/publication/34746881
ID  - 34746881
N1  - Megjelenés: 2024. március
LA  - English
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Horváth, László
TI  - A method for proving refinements of inequalities related to convex functions on intervals
JF  - MATHEMATICAL INEQUALITIES & APPLICATIONS
J2  - MATH INEQUAL APPL
VL  - 2024
PY  - 2024
IS  - 1
SP  - 85
EP  - 102
PG  - 18
SN  - 1331-4343
DO  - 10.7153/mia-2024-27-06
UR  - https://m2.mtmt.hu/api/publication/34684457
ID  - 34684457
LA  - English
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Horváth, László
TI  - Necessary and sufficient conditions for discrete inequalities of Jensen–Steffensen type with applications
JF  - JOURNAL OF INEQUALITIES AND APPLICATIONS
J2  - J INEQUAL APPL
VL  - 2024
PY  - 2024
IS  - 1
SN  - 1025-5834
DO  - 10.1186/s13660-023-03073-2
UR  - https://m2.mtmt.hu/api/publication/34482796
ID  - 34482796
AB  - In this paper we give a necessary and sufficient condition for the discrete Jensen inequality to be satisfied for real (not necessarily nonnegative) weights. The result generalizes and completes the classical Jensen–Steffensen inequality. The validity of the strict inequality is studied. As applications, we first give the form of our result for strongly convex functions, then we study discrete quasi-arithmetic means with real (not necessarily nonnegative) weights, and finally we refine the inequality obtained.
LA  - English
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Barát, János
AU  - Blázsik, Zoltán
TI  - Improved upper bound on the Frank number of 3-edge-connected graphs
JF  - EUROPEAN JOURNAL OF COMBINATORICS
J2  - EUR J COMBIN
VL  - 118
PY  - 2024
PG  - 6
SN  - 0195-6698
DO  - 10.1016/j.ejc.2023.103913
UR  - https://m2.mtmt.hu/api/publication/34478194
ID  - 34478194
AB  - In an orientation  of the graph , an arc  is deletable if and only if  is strongly connected. For a 3-edge-connected graph , the Frank number is the minimum 
 for which  admits  strongly connected orientations such that for every edge  of  the corresponding arc is deletable in at least one of the 
 orientations. Hörsch and Szigeti conjectured the Frank number is at most 3 for every 3-edge-connected graph . We prove an upper bound of 5, which improves the previous bound of 7.
LA  - English
DB  - MTMT
ER  - 

TY  - JOUR
AU  - Diblík, J
AU  - Pituk, Mihály
AU  - Szederkényi, Gábor
TI  - Large time behavior of nonautonomous linear differential equations with Kirchhoff coefficients
JF  - AUTOMATICA
J2  - AUTOMATICA
VL  - 161
PY  - 2024
PG  - 5
SN  - 0005-1098
DO  - 10.1016/j.automatica.2023.111473
UR  - https://m2.mtmt.hu/api/publication/34463676
ID  - 34463676
N1  - Brno University of Technology, Faculty of Civil Engineering, Veveří 331/95, Brno, 602 00, Czech Republic            
            Department of Mathematics, University of Pannonia, Egyetem út 10, Veszprém, H-8200, Hungary            
            HUN-REN-ELTE Numerical Analysis and Large Networks Research Group, Budapest, Hungary            
            Faculty of Information Technology and Bionics, Pázmány Péter Catholic University, Práter 50/a, Budapest, H-1083, Hungary            
            Systems and Control Laboratory, HUN-REN Institute for Computer Science and Control (SZTAKI), Kende u. 13-17, Budapest, H-1111, Hungary            
            Export Date: 5 February 2024            
            CODEN: ATCAA            
            Correspondence Address: Szederkényi, G.; Faculty of Information Technology and Bionics, Práter 50/a, Hungary; email: szederkenyi@itk.ppke.hu
LA  - English
DB  - MTMT
ER  -