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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
391

The influence of interfaces on the understanding of Mathematics in secondary schools in Afghanistan

Mojadadi, Abdul Rahman January 2010 (has links)
<p>he focus of this research is to establish whether there is a difference in the way the genders perceive the visualization of mathematics, with specific reference to set theory. The influence of the computing experience of students on their perceptions was also investigated. Interfaces were created for the teaching of set theory for learners in the first class of secondary school. Since the mother tongue of most the pupils is Dari the interface was made available in both Dari and English. The interfaces were used to gather the data for the researc</p>
392

The Twentieth-century Canon: An Analysis of Luigi Dallapiccola's Canonic Works from his 'Quaderno musicale di Annalibera'

Ravensbergen, Jacqueline 10 August 2012 (has links)
The compositional technique of cross partitioning is one of Luigi Dallapiccola's most used twelve-tone devices. Through a detailed analysis of three contrapuntal canonic movements from Dallapiccola's Quaderno Musicale di Annalibera, I examine his use of cross partitioning as a motivic tool and as a referential collection. The development of the BACH motive and the derivation of tone-row statements reflects on Dallapiccola's extensive use of cross partitioning and his compositional principles used to achieve a sense of polarity. Upon a preliminary analysis based on set-theory analysis set out by Joseph Straus I draw an interpretive analysis through Alegant's cross partitioning model as well as develop my own set of parameters for interpretation in regards to polarity which is based on intervallic stability.
393

The influence of interfaces on the understanding of Mathematics in secondary schools in Afghanistan

Mojadadi, Abdul Rahman January 2010 (has links)
<p>he focus of this research is to establish whether there is a difference in the way the genders perceive the visualization of mathematics, with specific reference to set theory. The influence of the computing experience of students on their perceptions was also investigated. Interfaces were created for the teaching of set theory for learners in the first class of secondary school. Since the mother tongue of most the pupils is Dari the interface was made available in both Dari and English. The interfaces were used to gather the data for the researc</p>
394

A theory of objects and visibility. A link between relative analysis and alternative set theory

O'Donovan, Richard 07 July 2011 (has links) (PDF)
The theory presented here stemmed from years of teaching analysis at pre-university level first using the concept of infinitesimal as defined in nonstandard analysis by Robinson, then the concept of ultrasmall as defined in our joint work with Hrbacek and Lessmann presented in the appendix. This research led to the question : If one has finite yet ultralarge quantities, is it possible to avoid infinite quantities ? The alternative set theory of Vopěnka is a theory of finite sets including classes that can be infinite. The theory of objects is a merger of certain axioms of Vopěnka with axioms that determine levels of visibility as in relative analysis. We took as first principle : $x\subseteq y\Rightarrow x\sqsubseteq y$, which specifies that if object $x$ is included in object $y$, then $x$ "appears" at the level of $y$. This statement would be false with infinite quantities and is in fact a characterisation of finite sets : this is a well-known theorem of nonstandard analysis. The introduction of this principle as starting point is making a strong point that all objects will be finite - in the usual sense of the word. The other founding axiom is Gordon and Andreev's axiom schema : If $\Phi$ is a formula, and if $\Phi(\emptyset)$ is true and that $\Phi(x)$ and $\Phi(y)$ imply $\Phi(x\cup\{y\})$, then $\Phi(x)$ is true for all $x$. An emphasis is made on the concept of contextual formulae. This concept is one of our contributions to relative analysis of Hrbacek and determines an equivalence to well-formed formulae. We show that the resulting system is relatively consistent with Hrbacek's FRIST and Péraire's RIST which are conservative extensions of ZFC. The theory of objects extends set theory of Zermelo and Fraenkel without choice and with negation of the infinity axiom. Integers and rationals are defined and endowed with an ultraproximity relation. A draft of a construction of "numeric grains" is presented : these numbers could prove to have properties sufficiently similar to real numbers to allow to perform analysis.
395

A Fuzzy Based Decision Support System For Locational Suitability Of Settlements / Odunpazari, Eskisehir Case Study

Ercan, Ismail 01 February 2006 (has links) (PDF)
Spatial Decision Making as a branch of decision making science deals with geographically related data in order to achieve complex spatial decision problems. Fuzzy set theory is one of the methods that can be used to come up with these types of problems. On the other hand, Geographical Information Systems (GIS) is one of the most powerful tools that we can use to accomplish spatial decision problems. Selection of the suitable site or land-use for the real estate is also a spatial decision making problem. When we consider the initial dynamics of the suitably located property from the point of view of value and potential we observe that the &ldquo / good location&rdquo / is the dominating factor. This study reports on the development of a kind of decision support system for locational suitability of settlements that integrates the fuzzy set (FZ) theory, a rule-based system (RBS) and GIS. This study is thought as the assistant for the property managers that are buyers and sellers. It can function as the property consultant for the buyers when they are looking for a property to buy and also it helps the real estate agencies to sell their properties. On the other hand, different scenarios of the potential areas according to the different user&rsquo / s preferences are depicted and they are joined and compared with the results of the vulnerability to earthquake hazards&rsquo / of the same area. Odunpazari - Eskisehir area is selected for implementation of the case study because of the data availability. As a result of this study, it can be said that most suitable property changes depending on the people&rsquo / s preferences. In addition, it is seen that most of the buildings that are locationally suitable are highly vulnerable to the earthquake hazards.
396

Critical Sets in Latin Squares and Associated Structures

Bean, Richard Winston Unknown Date (has links)
A critical set in a Latin square of order n is a set of entries in an n×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 m×2^α (m odd, α>=2) and m×2^α+1 (m odd, α>=2 and α≠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÷ 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.
397

Critical Sets in Latin Squares and Associated Structures

Bean, Richard Winston Unknown Date (has links)
A critical set in a Latin square of order n is a set of entries in an n×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 m×2^α (m odd, α>=2) and m×2^α+1 (m odd, α>=2 and α≠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÷ 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.
398

Critical Sets in Latin Squares and Associated Structures

Bean, Richard Winston Unknown Date (has links)
A critical set in a Latin square of order n is a set of entries in an n×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 m×2^α (m odd, α>=2) and m×2^α+1 (m odd, α>=2 and α≠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÷ 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.
399

Systémy kompaktních množin v deskriptivní teorii / Collections of compact sets in descriptive set theory

Vlasák, Václav January 2011 (has links)
1 Title: Collections of compact sets in descriptive set theory Author: Václav Vlasák Department: Department of Mathematical Analysis Supervisor: Doc. RNDr. Miroslav Zelený, Ph.D. Author's e-mail address: vlasakmm@volny.cz Abstract: This work consists of three articles. In Chapter 2, we dissert on the connections between complexity of a function f from a Polish space X to a Polish space Y and complexity of the set C(f) = {K ∈ K(X); f K is continuous}, where K(X) denotes the space of all compact subsets of X equipped with the Vietoris topology. We prove that if C(f) is analytic, then f is Borel; and assuming ∆1 2-Determinacy we show that f is Borel if and only if C(f) is coanalytic. Similar results for projective classes are also presented. In Chapter 3, we continue in our investigation of collection C(f) and also study its restriction on convergent sequences (C(f)). We prove that C(f) is Borel if and only if f is Borel. Similar results for projective classes are also presented. The Chapter 4 disserts on HN -sets, which form an important subclass of the class of sets of uniqueness for trigonometric series. We investigate the size of these classes which is reflected by the family of measures called polar which annihilate all the sets belonging to the given class. The main aim of this chapter is to answer in...
400

Reconnaissance de formes basée sur l'approche possibiliste dans les images mammographiques / Shape recognition based on possibilistic approach in mammographic images

Hmida, Marwa 09 December 2017 (has links)
Face à l'augmentation significative du taux de mortalité par cancer du sein chez les femmes ainsi que la croissance continue du nombre de mammographies réalisées chaque année, le diagnostic assisté par ordinateur devient de plus en plus impératif pour les experts. Dans notre travail de thèse, une attention particulière est accordée aux masses mammaires vu qu'elles représentent le signe de cancer du sein le plus couramment observé en mammographies. Néanmoins, ces images présentent un très faible contraste, ce qui fait que les frontières entre les tissus sains et les masses sont mal définies. C'est ainsi qu'il est difficile de pouvoir discerner avec précision ces masses et de leur définir un contour unique. En outre, la complexité et la grande variabilité des formes des masses mammaires rendent les tâches de diagnostic et de classification difficiles. Dans ce cadre, nous proposons un système d'aide au diagnostic dont le but est la segmentation de masses dans les régions d'intérêt et par la suite la classification de ces masses en deux catégories : bénignes et malignes. La première étape de segmentation est une étape assez délicate vu que les étapes postérieures à savoir la caractérisation et la classification y sont dépendantes. En effet, une mauvaise segmentation peut entrainer une mauvaise prise de décision. Un tel cas peut survenir en raison de l'incertitude et l'imprécision émanant de l'image mammographique. C'est pour cette raison que nous proposons une définition de contours flous permettant de prendre en compte ces types d'imperfections. Ces contours flous sont introduits dans l'énergie d'un contour actif pour modifier son mouvement et aboutir à une délimitation exacte des masses. Une fois les régions d'intérêt sont segmentées, nous présentons une méthode de classification de masses basée sur la théorie des possibilités qui permet de modéliser les ambigüités inhérentes aux connaissances exprimées par l'expert. En outre, cette méthode utilise essentiellement les descripteurs de forme pour caractériser les masses et décider de leur degré de gravité vu que la forme des masses constitue un bon indicateur de gravité.La validation et l'évaluation de ces deux méthodes sont réalisées en utilisant les régions d'intérêt contenant des masses extraites de la base MIAS. Les résultats obtenus sont très intéressants et les comparaisons effectuées ont mis en évidence leurs performances. / In view of the significant increase in breast cancer mortality rate among women as well as the continuous growth in number of mammograms performed each year, computer-aided diagnosis is becoming more and more imperative for experts. In our thesis work, special attention is given to breast masses as they represent the most common sign of breast cancer in mammograms. Nevertheless, mammographic images have very low contrast and breast masses possess ambiguous margins. Thus, it is difficult to distinguish them from the surrounding parenchymal. Moreover, the complexity and the large variability of breast mass shapes make diagnostic and classification challenging tasks.In this context, we propose a computer-aided diagnosis system which firstly segments masses in regions of interests and then classifies them as benign or malignant. Mass segmentation is a critical step in a computer-aided diagnosis system since it affects the performance of subsequent analysis steps namely feature analysis and classification. Indeed, poor segmentation may lead to poor decision making. Such a case may occur due to two types of imperfection: uncertainty and imprecision. Therefore, we propose to deal with these imperfections using fuzzy contours which are integrated in the energy of an active contour to get a fuzzy-energy based active contour model that is used for final delineation of mass.After mass segmentation, a classification method is proposed. This method is based on possibility theory which allows modeling the ambiguities inherent to the knowledge expressed by the expert. Moreover, since shape and margin characteristics are very important for differentiating between benign and malignant masses, the proposed method is essentially based on shape descriptors.The evaluation of the proposed methods was carried out using the regions of interest containing masses extracted from the MIAS base. The obtained results are very interesting and the comparisons made have demonstrated their performances.

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