This thesis investigates the development of a low-cost passive acoustic system for localizing moving vessels to monitor areas where human activities such as fishing, snorkeling and poaching are restricted. The system uses several off-the-shelf sensors with unsynchronized clocks where the Time Difference of Arrival (TDOA) or time delay is extracted by cross-correlation of the signal between paired sensors. The cross-correlation function uses phase correlation or Phase Transform (PHAT) which whitens the cross-spectrum in order to de-emphasize dominant frequency components. Using the locations of pairs of sensors as foci, hyperbolic equations can be defined using the time delay between them. With three or more sensors, multiple hyperbolic functions can be calculated which intersect at a unique point: the boat's location. It is also found that increasing separation distances between sensors decreased the correlation between the signals. However larger separation distances have better localization capability than with small distances. Experimental results from the Columbia and Willamette Rivers are presented to demonstrate performance.

[pt] Neste trabalho estudamos o teorema de Dandelin sobre seções cônicas. Contamos sua história e apresentamos uma demonstração elementar adequada a alunos de Ensino Médio. Indicamos também como utilizar recursos computacionais no ensino das propriedades das seções cônicas. / [en] In this work we study Dandelin s Theorem about conic sections. We tell its history and present an elementary proof that is adequate for students at High School level. We also indicate how to use computational resources in the teaching of the properties of conic sections.

The aim of this study is to compare and contrast the use of hyperbole or exaggeration in spoken Czech and English language. The research is based on comparative approach to two samples accounting for 100 hyperbolic instances in Czech and 100 instances of hyperbole in English. The Czech sample has been randomly excerpted from the oral part of the Czech National Corpus ORAL2008, whereas the English sample has been randomly excerpted from the "spoken context-govern" and "spoken demographic" sections of The British National Corpus. The two samples are subject to analysis. Firstly, the formal realization of hyperbole is examined. Secondly, the occurrences are classified semantically (quantitative versus qualitative hyperbole) and, thirdly, the lexico-semantics is examined (hyperbolic source domains). By this, the present study tests the hypothesis of universal hyperbolic source domains by examining the situation in Czech and English. Finally, the occurrence of conventionalized instances of hyperbole as opposed to creative instances of hyperbolic nonce-usages is examined. Last but not least, it is the aim of this study to provide the overall frequency figures of hyperbole in both languages.

Submitted by Luanna Matias (lua_matias@yahoo.com.br) on 2015-05-15T18:43:17Z No. of bitstreams: 2 Dissertação - Vitor Rodrigues Braga de Souza - 2014.pdf: 2674878 bytes, checksum: c37a3227405eafd0a6bcd6cdfe2ddf04 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luanna Matias (lua_matias@yahoo.com.br) on 2015-05-15T19:28:34Z (GMT) No. of bitstreams: 2 Dissertação - Vitor Rodrigues Braga de Souza - 2014.pdf: 2674878 bytes, checksum: c37a3227405eafd0a6bcd6cdfe2ddf04 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-05-15T19:28:34Z (GMT). No. of bitstreams: 2 Dissertação - Vitor Rodrigues Braga de Souza - 2014.pdf: 2674878 bytes, checksum: c37a3227405eafd0a6bcd6cdfe2ddf04 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2014-09-26 / In the rst part of this work, we present all conical with their cartesian equations and their graphs. Then, we made an approach to concepts of linear algebra, vector spaces, linear transformations, eigenvalues and eigenvectors in order to build matrices of linear transformations able to rotate, translate or even make these conical shear. Constructed matrices, GeoGebra software for constructing graphs obtained by transformation matrices were used. Besides this geometric part, we discuss the quadratic forms in order to identify a conic analyzing only the coe cients of its quadratic form and the eigenvalues. The end result was an excellent visual material built from software GeoGebra applying the concepts of Linear Algebra. We can not fail to mention that the construction of the taper in GeoGebra techniques that replace the ruler, compass and the string used by the ancient Greeks were implemented. / Na primeira parte desse trabalho, apresentamos todas as cônicas com suas respectivas equações cartesianas e seus respectivos grá cos. Em seguida, zemos uma abordagem de conceitos de Álgebra Linear, espaços vetoriais, transformações lineares, autovalores e autovetores a m de, construir as matrizes de transformações lineares capazes de rotacionar, transladar ou até fazer o cisalhamento destas cônicas. Construídas as matrizes, foi utilizado o software GeoGebra para a construção dos grá cos obtidos pelas matrizes de transformação. Além dessa parte geométrica, abordamos as formas quadráticas no intuito de identi car uma cônica analisando apenas os coe cientes da sua forma quadrática e os autovalores associados. O resultado nal foi um excelente material visual construído a partir do software GeoGebra aplicando os conceitos de Álgebra Linear. Não podemos deixar de citar que foram implementadas técnicas de construção das cônicas no GeoGebra que substituem a régua, o compasso e o barbante utilizados pelos gregos antigos.

TITLE: Agebraic Curves in History and School AUTHOR: Bc. Tomáš Fabián DEPARTMENT: The Department of mathematics and teaching of mathematics SUPERVISOR: prof. RNDr. Ladislav Kvasz, Dr. ABSTRACT: The thesis includes a series of exercises for senior high school students and the first year of university students. In these exercises, students will increase their knowledge about conics, especially how to draw them. Furthermore, students can learn about two unfamiliar curves: Conchoid and Quadratrix. All these curves are afterwards used for solving other problems - some Apollonius's problems, Three impossible constructions etc. Most of the construction is done in GeoGebra software. All the tasks are designed for students to learn how to work with this software. The subject discussed is put into historical context, and therefore the exercises are provided with historical commentary. The thesis also includes didactic notes, important or interesting solutions of exercises, possible issues, mistakes and another relevant notes. KEYWORDS: conic, circle, ellipse, parabola, hyperbole, conchoid, quadratrix, trisecting an angle, squaring the circle, rectification of the circle, doubling a cube, Apollonius's problem, GeoGebra

TITLE: Agebraic Curves in History and School AUTHOR: Bc. Tomáš Fabián DEPARTMENT: The Department of mathematics and teaching of mathematics SUPERVISOR: prof. RNDr. Ladislav Kvasz, Dr. ABSTRACT: The thesis includes a series of exercises for senior high school students and the first year of university students. In these exercises, students will increase their knowledge about conics, especially how to draw them. Furthermore, students can learn about two unfamiliar curves: Conchoid and Quadratrix. All these curves are afterwards used for solving other problems - some Apollonius's problems, Three impossible constructions etc. Most of the construction is done in GeoGebra software. All the tasks are designed for students to learn how to work with this software. The subject discussed is put into historical context, and therefore the exercises are provided with historical commentary. The thesis also includes didactic notes, important or interesting solutions of exercises, possible issues, mistakes and another relevant notes. KEYWORDS: conic, circle, ellipse, parabola, hyperbole, conchoid, quadratrix, trisecting an angle, squaring the circle, rectification of the circle, doubling a cube, Apollonius's problem, GeoGebra

The present thesis contributes to the theory of generalized Minkowski spaces as a continuation of Minkowski geometry, i.e., the geometry of finite-dimensional normed spaces over the field of real numbers. In a generalized Minkowski space, distance and length measurement is provided by a gauge, whose definition mimics the definition of a norm but lacks the symmetry requirement. This seemingly minor change in the definition is deliberately chosen. On the one hand, many techniques from Minkowski spaces can be adapted to generalized Minkowski spaces because several phenomena in Minkowski geometry simply do not depend on the symmetry of distance measurement. On the other hand, the possible asymmetry of the distance measurement set up by gauges is nonetheless meaningful and interesting for applications, e.g., in location science. In this spirit, the presentation of this thesis is led mainly by minimization problems from convex optimization and location science which are appealing to convex geometers, too. In addition, we study metrically defined objects, which may receive a new interpretation when we measure distances asymmetrically. To this end, we use a combination of methods from convex analysis and convex geometry to relate the properties of these objects to the shape of the unit ball of the generalized Minkowski space under consideration.

<p>У Докторској дисертацији је извршена методичкa трансформација садржа-<br />ја&nbsp; аналитичке&nbsp; геометрије,&nbsp; у&nbsp; наставном&nbsp; систему&ndash; настава&nbsp; уз&nbsp; помоћ<br />рачунара,&nbsp; адекватним&nbsp; избором&nbsp; садржаја,&nbsp; израдом&nbsp; одговарајућих<br />генеричких органи-затора уз коришћење образовног софтвераGeoGebra и<br />Mathematica. Обрађен је дидактички систем настава уз помоћ рачунара,<br />анализом међусобне зависности фактора наставе, анализом дидактичких<br />принципа,&nbsp; класификацијом&nbsp; и&nbsp; приказом&nbsp; наставних&nbsp; метода,&nbsp; уз&nbsp; подесно<br />формиране&nbsp; генеричке&nbsp; организаторе.&nbsp; Експериментално&nbsp; истраживање&nbsp; је<br />потврдило могућност примене наставе уз помоћ рачунара, као и позитиван<br />утицај на реализацију циљева и задатака, на укупан образовни учинак и<br />подизање нивоа ефикасности савремене наставе.</p> / <p>U Doktorskoj disertaciji je izvršena metodička transformacija sadrža-<br />ja&nbsp; analitičke&nbsp; geometrije,&nbsp; u&nbsp; nastavnom&nbsp; sistemu&ndash; nastava&nbsp; uz&nbsp; pomoć<br />računara,&nbsp; adekvatnim&nbsp; izborom&nbsp; sadržaja,&nbsp; izradom&nbsp; odgovarajućih<br />generičkih organi-zatora uz korišćenje obrazovnog softveraGeoGebra i<br />Mathematica. Obrađen je didaktički sistem nastava uz pomoć računara,<br />analizom međusobne zavisnosti faktora nastave, analizom didaktičkih<br />principa,&nbsp; klasifikacijom&nbsp; i&nbsp; prikazom&nbsp; nastavnih&nbsp; metoda,&nbsp; uz&nbsp; podesno<br />formirane&nbsp; generičke&nbsp; organizatore.&nbsp; Eksperimentalno&nbsp; istraživanje&nbsp; je<br />potvrdilo mogućnost primene nastave uz pomoć računara, kao i pozitivan<br />uticaj na realizaciju ciljeva i zadataka, na ukupan obrazovni učinak i<br />podizanje nivoa efikasnosti savremene nastave.</p> / <p>In this doctoral dissertation, methodical transformation of content analytic<br />geometry, is carried out, in the educational system - a computer-assisted<br />teaching, by appropriate selection of content, making appropriate generic<br />organizers using educational software GeoGebra and Mathematica.<br />Didactic teaching system, computer-assisted teaching, was processed, by<br />analyzing the factors of teaching and didactic principles, classification and<br />presentation of teaching methods, with the adequately created generic<br />organizers. Experimental research has confirmed the apossibility of<br />computer-assisted teaching, as well as a positive impact on the realization<br />of goals and tasks, on the overall educational impact and raising the<br />efficiency of modern teaching.</p>

Sistemas diferenciais quadráticos planares estão presentes em muitas áreas da matemática aplicada. Embora mais de mil artigos tenham sido publicados sobre os sistemas quadráticos ainda resta muito a se conhecer sobre esses sistemas. Problemas clássicos, e em particular o XVI problema de Hilbert, estão ainda em aberto para essa família. Um dos objetivos dos pesquisadores contemporâneos é obter a classificação topológica completa dos sistemas quadráticos. Devido ao grande número de parâmetros (essa família possui doze parâmetros e, aplicando transformações afins e reescala do tempo, reduzimos esse número a cinco, sendo ainda um número grande para se trabalhar) usualmente subclasses são consideradas nas investigações realizadas. Quando características específicas são levadas em consideração, o número de parâmetros é reduzido e o estudo se torna possível. Nesta tese estudamos principalmente duas subfamílias de sistemas quadráticos: a primeira possuindo um nó triplo semielemental e a segunda possuindo uma selanó semi elemental finita e uma selanó semielemental infinita formada pela colisão de uma sela infinita com um nó infinito. Os diagramas de bifurcação para ambas as famílias são tridimensionais. A família tendo um nó triplo gera 28 retratos de fase topologicamente distintos, enquanto o fecho da família tendo as selasnós dentro do espaço de bifurcação de sua forma normal gera 417. Polinômios invariantes são usados para construir os conjuntos de bifurcação e os retratos de fase topologicamente distintos são representados no disco de Poincaré. Os conjuntos de bifurcação são a união de superfícies algébricas e superfícies cuja presença foi detectada numericamente. Ainda nesta tese, apresentamos todos os retratos de fase de um sistema diferencial conhecido como modelo do tipo SIS (sistema suscetívelinfectadosuscetível, muito comum na matemática aplicada) e a classificação dos sistemas quadráticos possuindo hipérboles invariantes. Ambos sistemas foram investigados usando de polinômios invariantes afins. / Planar quadratic differential systems occur in many areas of applied mathematics. Although more than one thousand papers have been written on these systems, a complete understanding of this family is still missing. Classical problems, and in particular Hilberts 16th problem, are still open for this family. One of the goals of recent researchers is the topological classification of quadratic systems. As this attempt is not possible in the whole class due to the large number of parameters (twelve, but, after affine transformations and time rescaling, we arrive at families with five parameters, which is still a large number), many subclasses are considered and studied. Specific characteristics are taken into account and this implies a decrease in the number of parameters, which makes possible the study. In this thesis we mainly study two subfamilies of quadratic systems: the first one possessing a finite semielemental triple node and the second one possessing a finite semielemental saddlenode and an infinite semielemental saddlenode formed by the collision of an infinite saddle with an infinite node. The bifurcation diagram for both families are tridimensional. The family having the triple node yields 28 topologically distinct phase portraits, whereas the closure of the family having the saddlenodes within the bifurcation space of its normal form yields 417. Invariant polynomials are used to construct the bifurcation sets and the phase portraits are represented on the Poincaré disk. The bifurcation sets are the union of algebraic surfaces and surfaces whose presence was detected numerically. Moreover, we also present the analysis of a differential system known as SIS model (this kind of systems are easily found in applied mathematics) and the complete classification of quadratic systems possessing invariant hyperbolas.

The results of mathematics level 3 have always been a problem at TVET colleges as this hampers the certification rate and the progress of the students to level 4. Students who did not do well in the current subject are not allowed to register that subject in the following level. Even though the students are allowed to progress to level 4 they won’t be certificated for both levels until they pass the remaining subject. The above challenges made the researcher to check during the marking and moderation of November / December examination the course of poor results for mathematics level 3. In the process of checking the researcher discovered that rectangular hyperbola is one of the topics that the students of mathematics level 3 are struggling with. This study therefore focuses on exploring the challenges faced by TVET Level 3 NCV students in understanding the hyperbolic function in mathematics. In addition to the literature review, an empirical investigation based on a qualitative approach and involving semi-structured interviews with the students of a TVET college in North West was conducted to collect data. The analysis of documents relevant to the study was also used as the other method. The study used participatory action research, where the researcher, collaborators and students work alongside each other to collect data and to improve practice and follow the spiral pattern of reflection, analysing the results and adapting the action. The research design and methodology was qualitative. This helped the researcher to understand the challenges students faced in the learning of rectangular hyperbola and also came up with ways to minimise those challenges. The data collection methods used was interviewing using semi-structured questions, pre-test and post-tests. During data collection different interventions (IN1 –IN3) was used depending on the understanding of the students. For ethical consideration, ethical clearance was obtained from UNISA. DHET, the principal of the college, collaborators, parents and students will also give written consent on forms which will be sent out explaining what we envisage. Since research was voluntary, an explanation was given that this was not compulsory and that participation was completely voluntary and that they could withdraw at any time. In this study, various methods to empower students were recommended. Recommendations are also made on what was found in this study, as are recommendations for further study. / Mathematics Education / M. Ed. (Mathematics Education)