A critical set in a Latin square of order n is a set of entries in an n x n array which can be embedded in precisely one Latin square of order n, with the property that if any entry of the critical set is deleted, the remaining set can be embedded in more than one Latin square of order n. The number of critical sets grows super-exponentially as the order of the Latin square increases. It is difficult to find patterns in Latin squares of small order (order 5 or less) which can be generalised in the process of creating new theorems. Thus, I have written many algorithms to find critical sets with various properties in Latin squares of order greater than 5, and to deal with other related structures. Some algorithms used in the body of the thesis are presented in Chapter 3; results which arise from the computational studies and observations of the patterns and subsequent results are presented in Chapters 4, 5, 6, 7 and 8. The cardinality of the largest critical set in any Latin square of order n is denoted by lcs(n). In 1978 Curran and van Rees proved that lcs(n)<=n2-n. In Chapter 4, it is shown that lcs(n)<=n2-3n+3. Chapter 5 provides new bounds on the maximum number of intercalates in Latin squares of orders mX2^alpha (m odd, alpha>=2) and mX2^alpha+1 (m odd, alpha>=2 and alpha not equal to 3), and a new lower bound on lcs(4m). It also discusses critical sets in intercalate-rich Latin squares of orders 11 and 14. In Chapter 6 a construction is given which verifies the existence of a critical set of size n2 divided by 4 + 1 when n is even and n>=6. The construction is based on the discovery of a critical set of size 17 for a Latin square of order 8. In Chapter 7 the representation of Steiner trades of volume less than or equal to nine is examined. Computational results are used to identify those trades for which the associated partial Latin square can be decomposed into six disjoint Latin interchanges. Chapter 8 focusses on critical sets in Latin squares of order at most six and extensive computational routines are used to identify all the critical sets of different sizes in these Latin squares.

A critical set in a Latin square of order n is a set of entries in an n x n array which can be embedded in precisely one Latin square of order n, with the property that if any entry of the critical set is deleted, the remaining set can be embedded in more than one Latin square of order n. The number of critical sets grows super-exponentially as the order of the Latin square increases. It is difficult to find patterns in Latin squares of small order (order 5 or less) which can be generalised in the process of creating new theorems. Thus, I have written many algorithms to find critical sets with various properties in Latin squares of order greater than 5, and to deal with other related structures. Some algorithms used in the body of the thesis are presented in Chapter 3; results which arise from the computational studies and observations of the patterns and subsequent results are presented in Chapters 4, 5, 6, 7 and 8. The cardinality of the largest critical set in any Latin square of order n is denoted by lcs(n). In 1978 Curran and van Rees proved that lcs(n)<=n2-n. In Chapter 4, it is shown that lcs(n)<=n2-3n+3. Chapter 5 provides new bounds on the maximum number of intercalates in Latin squares of orders mX2^alpha (m odd, alpha>=2) and mX2^alpha+1 (m odd, alpha>=2 and alpha not equal to 3), and a new lower bound on lcs(4m). It also discusses critical sets in intercalate-rich Latin squares of orders 11 and 14. In Chapter 6 a construction is given which verifies the existence of a critical set of size n2 divided by 4 + 1 when n is even and n>=6. The construction is based on the discovery of a critical set of size 17 for a Latin square of order 8. In Chapter 7 the representation of Steiner trades of volume less than or equal to nine is examined. Computational results are used to identify those trades for which the associated partial Latin square can be decomposed into six disjoint Latin interchanges. Chapter 8 focusses on critical sets in Latin squares of order at most six and extensive computational routines are used to identify all the critical sets of different sizes in these Latin squares.

32 Reunión Latinoamericana de Matemática Educativa (Relme), evento desarrollado en la Universidad de Medellín, Colombia, del 2 al 6 de Junio de 2018. / El trabajo de investigación tiene como objetivo determinar la incidencia de la evaluación actitudinal en la formación de los alumnos de Matemática Discreta de la Universidad Peruana de Ciencias Aplicadas, en el modelo educativo basado en competencias. Se trabajó con todas las secciones de Matemática Discreta del ciclo 2018-1 para la aplicación del modelo. Para la comparación se han considerado los resultados de cinco ciclos anteriores, antes de que se aplicara el modelo, a los cuales se les denomina resultados históricos del curso. Con los resultados obtenidos en este primer ciclo podremos ajustar el modelo, y obtener luego resultados satisfactorios. / The aim of the research work is to determine the incidence of attitudinal evaluation in the training of Discrete Mathematics students of the Peruvian University of Applied Sciences, in the competency-based educational model. We worked with all the Discrete Mathematics sections of cycle 2018-1 for the application of the model. For the comparison, the results of five previous cycles have been considered, before the model was applied, which are called historical course results. With the results obtained in this first cycle we can adjust the model, and then obtain satisfactory results.

Submitted by ANA KARLA PEREIRA RODRIGUES (anakarla_@hotmail.com) on 2017-08-29T16:22:32Z No. of bitstreams: 1 arquivototal.pdf: 1866226 bytes, checksum: e3b8717f65b0ca3de6fc9c38cc41f7e2 (MD5) / Approved for entry into archive by Viviane Lima da Cunha (viviane@biblioteca.ufpb.br) on 2017-08-30T11:44:43Z (GMT) No. of bitstreams: 1 arquivototal.pdf: 1866226 bytes, checksum: e3b8717f65b0ca3de6fc9c38cc41f7e2 (MD5) / Made available in DSpace on 2017-08-30T11:44:43Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 1866226 bytes, checksum: e3b8717f65b0ca3de6fc9c38cc41f7e2 (MD5) Previous issue date: 2016-05-27 / I show this thesis linear recurrences starting with a brief historical review of the main authors of some problems of linear recurrences. Analyze elementary sequences, positional formulas, recursive methods, arithmetic and geometric progressions. Later, I will distinguish what are relations of relapses and recurrences following equations with the explanation of the solution of a recurrence, exposed in some instances and also the rst recurrence settings and second orders with their ratings. Soon after I'll discuss brie y the respect of some types of third-order recurrences and also see some generalizations to higher order. Treat, nishing this work, applications of recurrences using the foundations mentioned above and problems involving combinatorial. / Mostrarei nesta dissertação as recorrências lineares começando com um breve comentário histórico sobre os principais autores de alguns problemas de recorrências lineares. Analisarei sequências elementares, fórmulas posicionais, métodos recursivos, progressões aritméticas e geométricas. Posteriormente, diferenciarei o que são relações de recorrências e equações de recorrências seguindo com a explicação da solução de uma recorrência, exposta em alguns exemplos e também as de nições de recorrências de primeira e segunda ordens com suas classi cações. Logo após discorrerei, brevemente, à respeito de alguns tipos de recorrências de terceira ordem e veremos também algumas generalizações para ordem superior. Tratarei, nalizando neste trabalho, aplicações das recorrências utilizando as fundamentações referidas anteriormente e problemas envolvendo combinatória.

Today there exist few non-smooth multi-domain simulation tools using time-discretized Lagrangian mechanics for circuits.The main goal is to show that itis possible to use a semi-implicit, parameter free non-smooth variational timestepper to simulate the circuits with time-steps proportional to the system timescales.This is demonstrated by implementing and performing extensive numericaltests for various types of electrical, mechanical and hydraulic components anddemonstrate that the components are stable, with the correct behavior whenthe system is solved using a modified block pivot solver.Simulation results shows that piecewise linear models are enough for thesimple switching circuits in this thesis. / Idag finns det få simulatorer för icke-släta multidomän kretsar som bygger på tidsdiskretisering av Lagranges ekvationer. Huvudmålet är att visa att det är möjligt att använda en semi-implicit, parameter fri icke-slät diskret lösare för att simulera kretsar med tidssteg proportionella mot systemens tidsskalor. Detta visas genom att implementera olika typer av elektriska, mekaniska och hydrauliska komponenter samt att visa att komponenterna är stabila och har rätt beteende när systemet simuleras av en modifierad block pivot lösare. Simulerings resultaten visar att icke-släta Newton metoder med styckvis-linjära komponenter och komplementära villkor är tillräkligt för att simulera brytande komponponenter i de simulerande kretsarna.

Mobile Ad hoc network routing protocols have been divided in several different categories such as Reactive and Proactive Routing Protocol. The performances of these categories are evaluated in different scenario with TCP variants. We present a comprehensive TCP performance evaluation study to understand the nature of the TCP performance in different scenarios with variable amount of payload and number of nodes. The traffic consists of three different packet sizes i.e. 512, 1000, 1500 bytes each. Three different routing protocols (AODV, DSR and TORA) are to be evaluated with three different TCP variants (Tahoe, Reno and New Reno) in three different scenarios having 3, 5 and 8 nodes. The performances parameters on the basis of which routing protocols are to be graded are mainly throughput, congestion window and delay. Conclusions are drawn based on the simulation results and the comparisons between them have been elaborated. / N.W.F.P PAKISTAN. Mobile no: 0092-3339173438

A Hamilton cycle in a graph is a cycle that passes through every vertex of the graph. A graph is called Hamiltonian if it contains such a cycle. In this thesis we investigate two classes of graphs, defined by local criteria. Graphs in these classes, with a simple set of exceptions K, were proven to be Hamiltonian by Asratian, Broersma, van den Heuvel, and Veldman in 1996 and by Asratian in 2006, respectively. We prove here that in addition to being Hamiltonian, graphs in these classes have stronger cyclic properties. In particular, we prove that if a graph G belongs to one of these classes, then for each vertex x in G there is a sequence of cycles such that each cycle contains the vertex x, and the shortest cycle in the sequence has length at most 5; the longest cycle in the sequence is a Hamilton cycle (unless G belongs to the set of exceptions K, in which case the longest cycle in the sequence contains all but one vertex of G); each cycle in the sequence except the first contains all vertices of the previous cycle, and at most two other vertices. Furthermore, for each edge e in G that does not lie on a triangle, there is a sequence of cycles with the same three properties, such that each cycle in the sequence contains the edge e.

The Goldbach conjecture states that every even number greater than 2 can be written as a sumof two prime numbers. This thesis will go through the necessary theory and the backgroundto the problem at hand. Some numerical results connected to the Goldbach conjecture suchas displaying Goldbach partitions will be presented visually and interpretations of what theseresults yield will be made. How the Goldbach partitions behave for large even numbers will bestudied as well as patterns within these results. The tendencies in the graphical results supportthat the Goldbach conjecture could be true.

A star edge coloring is any edge coloring which is both proper and contains no cycles or path of length four which are bicolored, and the star chromatic index of a graph is the smallest number of colors for which that graph can be star edge colored. Star edge coloring is a relatively new field in graph theory, and very little is known regarding upper bounds of the star chromatic index of most graph types, one of these families being multipartite graphs. We investigate a method for obtaining upper bounds on the star chromatic index of complete multipartite graphs. The basic idea is to decompose such graphs into smaller complete bipartite graphs and applying known upper bounds for such graphs.This method has also been implemented and we present a hypothesis based on simulations.

This study attempts to improve forecasts of solar energy production (SEP), so that energy trading companies can propose more accurate bids to Nord Pool. The aim ismake solar energy a more lucrative business, and therefore lead to more investments in this green energy form. The model that is introduced is a hidden Markov model (HMM) that we call a Time-dynamic Markov-chain (TDMC). The TDMC is presented in general, but applied to the energy sector SE4 in south of Sweden. A simple linear regression model is used to compare with the performance of the TDMC model. Regarding the mean absolute error (MAE) and the root-mean-square error (RMSE), the TDMC model outperforms a simple linear regression; both when the training data is relatively fresh and also when the training data has not been updated in over 300 days. A paired t-test also shows a non-significant deviation from the true SEP per day, at the 0.05 significance level, when simulating the first two months of 2023 with the TDMC model. The simple linear regression model, however, shows a significant difference from reality, in comparison.