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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.
61

Números figurados e as sequências recursivas : uma atividade didática envolvendo números triangulares e quadrados

Chiconello, Luis Alexandre 11 March 2013 (has links)
Made available in DSpace on 2016-06-02T20:29:21Z (GMT). No. of bitstreams: 1 5050.pdf: 4225946 bytes, checksum: eef403ca886d7a47c3c8886fee5bc0f4 (MD5) Previous issue date: 2013-03-11 / Financiadora de Estudos e Projetos / The shortage of activities regarding recursive defined sequences, allied to the importance of this theme to young students has been contested in at least twenty years of experience teaching Mathematics. The elaboration of a learning product, in a form of sheets of activities which gradually lead the student to the understanding of the concept of recursion, the pattern recognition, conjectures tests and formulas acquisition, could be inferred by the application of these sheets of activities in two high school classrooms in a technical state school. The data attained from these activities applications were analyzed and compared to the previously formed hypothesis (previous analysis) which were formed during the elaboration of the sheets of activities. The investigation method used was the Didactical Engineering. The students did the activities in groups of two or three students .They were participative and felt challenged in doing every step (lessons) proposed in the sheets. It was verified that the teaching material developed works, as it reached its main goals, the biggest one, the students learning. It is believed that the material developed may be useful to other teachers who may wish to develop the theme proposed in their classrooms, even adapting them to their students needs. This work brought to this author a great profession evolution which began with the theme choice, passed through the development of the material, the application in the classes and finally in the reflection of everything that was done and that is recorded in these notes. / A escassez de atividades envolvendo sequências definidas recursivamente, aliada à importância desse tema para jovens estudantes, foi constatada em pelo menos vinte anos de experiência dando aulas de matemática. A elaboração de um produto de ensino, na forma de folhas de atividades que gradativamente levam o estudante à compreensão do conceito de recursividade, reconhecimento de padrões, testes de conjecturas e obtenção de fórmulas, pôde ser aferida através da aplicação dessas folhas de atividades em duas salas do ensino médio de uma escola técnica estadual. Os dados obtidos dessas aplicações foram analisados e comparados com as hipóteses levantadas (análises prévias), sendo estas feitas durante a elaboração das folhas de atividades. A metodologia de investigação usada foi a Engenharia Didática. Os alunos fizeram as atividades em grupos de dois ou três, foram participativos e se sentiram bastante estimulados em realizar todas as etapas (lições) propostas nas folhas. Constatou-se que o material de ensino produzido funciona, pois atingiu seus objetivos principais, sendo o maior deles o aprendizado do aluno. Acredita-se que o material elaborado possa ser útil a outros professores que desejarem desenvolver o tema proposto em suas aulas, podendo mesmo adaptá-los à realidade de suas turmas. Este trabalho trouxe, para esse autor, uma grande evolução profissional que se iniciou na escolha do tema, passou pela elaboração do material construído, pela aplicação nas turmas e finalmente pela reflexão de tudo que foi feito e que se encontra registrado nessas notas.
62

Se souvenir et revenir : approche théorique et méthodologique des stratégies de déplacement récursif et de leurs conséquences populationnelles / Remembering and coming back : a theoretical and methodological approach to recursive movement strategies and their population-level consequences

Riotte-Lambert, Louise 18 October 2016 (has links)
Les patrons récursifs de déplacement, où l’individu revient à des sites déjà visités, sont très répandus. L’utilisation de la mémoire, supposée être avantageuse lorsque l’environnement est prévisible, pourrait être sous-jacente à l’émergence de ces patrons. Cependant, notre compréhension de l’interface mémoire-déplacement a jusqu'à présent été limitée par un manque de méthodes adaptées et d’investigation théorique des avantages de l’utilisation de la mémoire et des patrons qui en émergent. Au cours de cette thèse j’ai cherché à combler en partie ces manques. Je propose ici trois nouveaux cadres d'analyse des patrons récursifs de déplacement. Le premier délimite les zones les plus fréquemment revisitées par un individu, le deuxième détecte la périodicité dans les revisites de sites connus, et le troisième définit formellement et quantifie la routine de déplacement en termes de répétitivité de la séquence de déplacement, et propose un algorithme pour détecter les sous-séquences répétées. A l'aide d'un modèle individu-centré, nous montrons que l'utilisation de la mémoire dans un environnement prévisible est très avantageuse énergétiquement comparée à une stratégie de recherche sans mémoire, y compris en situation de compétition, et qu'elle mène à l'émergence de domaines vitaux stables et à la ségrégation spatiale entre individus. L'utilisation de la mémoire invalide plusieurs hypothèses très courantes faites par les études populationnelles, en menant à une forte déplétion de l’environnement, à une augmentation de la taille de la population à l’équilibre, et à une relation non linéaire entre la taille de population totale et l’intensité de compétition localement ressentie par les individus. Ainsi, ma thèse contribue à une meilleure compréhension des conséquences de la mémoire sur la valeur sélective des individus, sur les patrons de déplacement, et sur la démographie des populations. Elle propose des méthodes innovantes pour quantifier et caractériser les patrons récursifs de déplacement pouvant émerger de son utilisation. Ces méthodes devraient ouvrir de nouvelles opportunités de comparaisons entre individus de différentes populations ou espèces qui permettront le test d'hypothèses sur les pressions de sélection favorisant l'utilisation de la mémoire. / Recursive movement patterns, by which an individual returns to already visited sites, are very common. Memory use, hypothesized to be advantageous when the environment is predictable, could underlie the emergence of these patterns. However, our understanding of the memory-movement interface has been limited by two knowledge gaps. We still lack appropriate methodologies and theoretical knowledge of the advantages of memory use and of the patterns that emerge from it. During this PhD project, I aimed at filling in some of these gaps. I present here three new frameworks for the analysis of recursive movement patterns. The first one delimits the areas most frequently revisited by an individual, the second one detects periodic revisit patterns, and the third one formally defines and quantifies routine movement behaviour in terms of movement sequence repetitiveness, and presents an algorithm that detects the sub-sequences that are repeated. Using an individual-based model, we show that memory use, when the environment is predictable, is very energetically advantageous compared to foraging strategies that do not use memory, including in a situation of competition, and that it leads to the emergence of stable Home Ranges and spatial segregation between individuals. Memory use invalidates several hypotheses very commonly made in population studies, by leading to a stronger environmental depletion, to a higher equilibrium population size, and to a nonlinear relationship between the total population size and the individually-experienced intensity of competition. Therefore, my PhD thesis contributes to a better understanding of the consequences of memory use for the fitness of individuals, for movement patterns, and for population dynamics. It offers innovative methodologies that quantify and characterize recursive movement patterns that can emerge from its use. These methods should open new opportunities for the comparison of the movements of individuals from different populations and species, and thus the testing of hypotheses about the pressures that select for memory use.
63

Swedish-English Verb Frame Divergences in a Bilingual Head-driven Phrase Structure Grammar for Machine Translation / Skillnader i verbramar mellan svenska och engelska i en tvåspråkig HPSG-grammatik för maskinöversättning

Stymne, Sara January 2006 (has links)
In this thesis I have investigated verb frame divergences in a bilingual Head-driven Phrase Structure Grammar for machine translation. The purpose was threefold: (1) to describe and classify verb frame divergences (VFDs) between Swedish and English, (2) to practically implement a bilingual grammar that covered many of the identified VFDs and (3) to find out what cases of VFDs could be solved and implemented using a common semantic representation, or interlingua, for Swedish and English. The implemented grammar, BiTSE, is a Head-driven Phrase Structure Grammar based on the LinGO Grammar Matrix, a language independent grammar base. BiTSE is a bilingual grammar containing both Swedish and English. The semantic representation used is Minimal Recursion Semantics (MRS). It is language independent, so generating from it gives all equivalent sentences in both Swedish and English. Both the core of the languages and a subset of the identified VFDs are successfully implemented in BiTSE. For other VFDs tentative solutions are discussed. MRS have previously been proposed as suitable for semantic transfer machine translation. I have shown that VFDs can naturally be handled by an interlingual design in many cases, minimizing the need of transfer. The main contributions of this thesis are: an inventory of English and Swedish verb frames and verb frame divergences; the bilingual grammar BiTSE and showing that it is possible in many cases to use MRS as an interlingua in machine translation.
64

Portfolio of original compositions : dynamic audio composition via space and motion in virtual and augmented environments

Pecino Rodriguez, Jose Ignacio January 2015 (has links)
Electroacoustic music is often regarded as not being sufficiently accessible to the general public because of its sound-based abstract quality and the complexity of its language. Live electronic music introduces the figure of the performer as a gestural bodily agent that re-enables our multimodal perception of sound and seems to alleviate the accessibility dilemma. However, live electronic music generally lacks the level of detail found in studio-based fixed media works, and it can hardly be transferred outside the concert hall situation (e.g. as a video recording) without losing most of its fresh, dynamic and unpredictable nature. Recent developments in 3D simulation environments and game audio technologies suggest that alternative approaches to music composition and distribution are possible, presenting an opportunity to address some of these issues. In particular, this Portfolio of Compositions proposes the use of real and virtual space as a new medium for the creation and organisation of sound events via computer-simulated audio-sources. In such a context, the role of the performer is sometimes assumed by the listener itself, through the operation of an interactive-adaptive system, or it is otherwise replaced by a set of automated but flexible procedures. Although all of these works are sonic centric in nature, they often present a visual component that reinforces the multimodal perception of meaningful musical structures, either as real space locations for sonic navigation (locative audio), or live visualisations of physically-informed gestural agents in 3D virtual environments. Consequently, this thesis draws on general game-audio concepts and terminology, such as procedural sound, non-linearity, and generative music; but it also embraces game development tools (game engines) as a new methodological and technological approach to electroacoustic music composition. In such context, space and the real-time generation, control, and manipulation of assets combine to play an important role in broadening the routes of musical expression and the accessibility of the musical language. The portfolio consists of six original compositions. Three of these works–Swirls, Alice - Elegy to the Memory of an Unfortunate Lady, and Alcazabilla–are interactive in nature and they required the creation of custom software solutions (e.g. SonicMaps) in order to deal with open-form musical structures. The last three pieces–Singularity, Apollonian Gasket, and Boids–are based on fractal or emergent behaviour models and algorithms, and they propose a non-interactive linear organisation of sound materials via real-time manipulation of non-conventional 3D virtual instruments. These original instrumental models exhibit strong spatial and kinematic qualities with an abstract and minimal visual representation, resulting in an extremely efficient way to build spatialisation patterns, texture, and musical gesture, while preserving the sonic-centric essence of the pieces.
65

Ungeordnete Zahlpartitionen mit k Parts, ihre 2^(k - 1) Typen und ihre typspezifischen erzeugenden Funktionen

Lösch, Manfred 27 May 2014 (has links)
Die 2^(k – 1) Typen der ungeordneten Zahlpartitionen mit k Parts (k-Partitionen) werden hier mit Hilfe der geordneten Partitionen von k definiert. Für jeden Typ gibt es eine erzeugende Funktion der geschlossenen Form mit eindeutiger Nummerierung. Die bekannte erzeugende Funktion der k-Partitionen ist die Summe dieser 2^(k – 1) typspezifischen erzeugenden Funktionen. Die Expansion dieser typspezifischen erzeugenden Funktionen in (unendlich lange) Potenzreihen ist rekursiv möglich. Untersucht werden Zerlegungen von erzeugenden Funktionen der einfachen Typen in erzeugende Funktionen anderer Typen. Damit lassen sich Bijektionen zwischen den Partitionen verschiedener Typen aufspüren. Die typspezifischen Betrachtungen werden auf die geordneten Partitionen und auf ihre erzeugenden Funktionen ausgeweitet.:1. Kurze Vorbetrachtung 2. Die Typen der ungeordneten k-Partitionen 3. Konstruktion einer typspezifischen GF (generating function) 4. Nummerierung und Symbolik für typspezifische GF’s 5. Die Summe aller typspezifischen GF’s 6. Multiplizieren elementarer Potenzreihen, Erzeugungsformeln 7. Rekursives Expandieren typspezifischer GF’s 8. Zahlen, die in k-Partitionen aller 2^(k – 1) Typen zerlegbar sind 9. Die Konjugierten der typspezifischen k-Partitionen 10. GF-Zerlegungen 10.1 Zerlegung der GF des Typs r = 2 10.2 Zerlegung der GF des Typs r = 3 11. Die typspezifischen GF’s der geordneten Partitionen 12. Literaturverzeichnis 13. Nachwort
66

Ungeordnete Zahlpartitionen mit k Parts, ihre 2^(k - 1) Typen und ihre typspezifischen erzeugenden Funktionen

Lösch, Manfred 06 December 2012 (has links)
Jede ungeordnete Zahlpartition mit k Parts (k-Partiton) hat einen Typ, der mittels einer geordneten Partition von k definiert werden kann. Es können somit 2^(k - 1) Typen definiert werden. Pro Typ gibt es eine eindeutig nummerierbare erzeugende Funktion der geschlossenen Form. Mit Rekursionen können diese Funktionen in (unendlich lange) Potenzreihen expandiert werden. Mit diesen erzeugenden Funktionen lassen sich Bijektionen zwischen den Partitionsmengen verschiedener Typen aufspüren.:1. Kurze Vorbetrachtung 2. Typen der ungeordneten k-Partitionen 3. Konstruktion der GF (generating function) des allgemeinen Typs 4. Nummerierung der konstruierten GF 5. Weitere Analysen zur konstruierten GF 6. Die konjugierten der typspezifischen k-Partitionen 7. Vereinfachte GF-Symbolik 8. Eine programmierbare Basis-GF 9. Dekomposition von Q(x, k) in typspezifische GF''s 10. Rekursives Expandieren typspezifischer GF''s 11. GF-Zerlegungen und Bijektionen 12. Zahlen, die in k-Partitionen aller Typen zerlegbar sind 13. Referenzen
67

Composable, Sound Transformations for Nested Recursion and Loops

Kirshanthan Sundararajah (16647885) 26 July 2023 (has links)
<p>    </p> <p>Programs that use loops to operate over arrays and matrices are generally known as <em>regular programs</em>. These programs appear in critical applications such as image processing, differential equation solvers, and machine learning. Over the past few decades, extensive research has been done on composing, verifying, and applying scheduling transformations like loop interchange and loop tiling for regular programs. As a result, we have general frameworks such as the polyhedral model to handle transformations for loop-based programs. Similarly, programs that use recursion and loops to manipulate pointer-based data structures are known as <em>irregular programs</em>. Irregular programs also appear in essential applications such as scientific simulations, data mining, and graphics rendering. However, there is no analogous framework for recursive programs. In the last decade, although many scheduling transformations have been developed for irregular programs, they are ad-hoc in various aspects, such as being developed for a specific application and lacking portability. This dissertation examines principled ways to handle scheduling transformations for recursive programs through a unified framework resulting in performance enhancement. </p> <p>Finding principled approaches to optimize irregular programs at compile-time is a long-standing problem. We specifically focus on scheduling transformations that reorder a program’s operations to improve performance by enhancing locality and exploiting parallelism. In the first part of this dissertation, we present PolyRec, a unified general framework that can compose and apply scheduling transformations to nested recursive programs and reason about the correctness of composed transformations. PolyRec is a first-of-its-kind unified general transformation framework for irregular programs consisting of nested recursion and loops. It is built on solid theoretical foundations from the world of automata and transducers and provides a fundamentally novel way to think about recursive programs and scheduling transformations for them. The core idea is designing mechanisms to strike a balance between the expressivity in representing the set of dynamic instances of computations, transformations, and dependences and the decidability of checking the correctness of composed transformations. We use <em>multi-tape </em>automata and transducers to represent the set of dynamic instances of computations and transformations, respectively. These machines are similar yet more expressive than their classical single-tape counterparts. While in general decidable properties of classical machines are undecidable for multi-tape machines, we have proven that those properties are decidable for the class of machines we consider, and we present algorithms to verify these properties. Therefore these machines provide the building blocks to compose and verify scheduling transformations for nested recursion and loops. The crux of the PolyRec framework is its regular string-based representation of dynamic instances that allows to lexicographically order instances identically to their execution order. All the transformations considered in PolyRec require different ordering of these strings representable only with <em>additive </em>changes to the strings. </p> <p>Loop transformations such as <em>skewing </em>require performing arithmetic on the representation of dynamic instances. In the second part of this dissertation, we explore this space of transformations by introducing skewing to nested recursion. Skewing plays an essential role in producing easily parallelizable loop nests from seemingly difficult ones due to dependences carried across loops. The inclusion of skewing for nested recursion to PolyRec requires significant extensions to representing dynamic instances and transformations that facilitate <em>performing arithmetic using strings</em>. First, we prove that the machines that represent the transformations are still composable. Then we prove that the representation of dependences and the algorithm that checks the correctness of composed transformations hold with minimal changes. Our new extended framework is known as UniRec, since it resembles the unimodular transformations for perfectly nested loop nests, which consider any combination of the primary transformations interchange, reversal, and skewing. UniRec opens possibilities of producing newly composed transformations for nested recursion and loops and verifying their correctness. We claim that UniRec completely subsumes the unimodular framework for loop transformations since nested recursion is more general than loop nests. </p>
68

Applications of Integer Quadratic Programming in Control and Communication

Axehill, Daniel January 2005 (has links)
The main topic of this thesis is integer quadratic programming with applications to problems arising in the areas of automatic control and communication. One of the most widespread modern control principles is the discrete-time method Model Predictive Control (MPC). The main advantage with MPC, compared to most other control principles, is that constraints on control signals and states can easily be handled. In each time step, MPC requires the solution of a Quadratic Programming (QP) problem. To be able to use MPC for large systems, and at high sampling rates, optimization routines tailored for MPC are used. In recent years, the range of application of MPC has been extended from constrained linear systems to so-called hybrid systems. Hybrid systems are systems where continuous dynamics interact with logic. When this extension is made, binary variables are introduced in the problem. As a consequence, the QP problem has to be replaced by a far more challenging Mixed Integer Quadratic Programming (MIQP) problem. Generally, for this type of optimization problems, the computational complexity is exponential in the number of binary optimization variables. In modern communication systems, multiple users share a so-called multi-access channel, where the information sent by different users is separated by using almost orthogonal codes. Since the codes are not completely orthogonal, the decoded information at the receiver is slightly correlated between different users. Further, noise is added during the transmission. To estimate the information originally sent, a maximum likelihood problem involving binary variables is solved. The process of simultaneously estimating the information sent by multiple users is called multiuser detection. In this thesis, the problem to efficiently solve MIQP problems originating from MPC is addressed. Two different algorithms are presented. First, a polynomial complexity preprocessing algorithm for binary quadratic programming problems is presented. By using the algorithm, some, or all, binary variables can be computed efficiently already in the preprocessing phase. In simulations, the algorithm is applied to unconstrained MPC problems with a mixture of real and binary control signals. It has also been applied to the multiuser detection problem, where simulations have shown that the bit error rate can be significantly reduced by using the proposed algorithm as compared to using common suboptimal algorithms. Second, an MIQP algorithm tailored for MPC is presented. The algorithm uses a branch and bound method where the relaxed node problems are solved by a dual active set QP algorithm. In this QP algorithm, the KKT-systems are solved using Riccati recursions in order to decrease the computational complexity. Simulation results show that both the QP solver and the MIQP solver proposed have lower computational complexity than corresponding generic solvers. / <p>Report code: LiU-TEK-LIC-2005:71.</p>
69

A symptom as part of a recursive process of interaction in a black family

Mashiane, Selema 03 1900 (has links)
This study is an endeavour to demonstrate the applicability of constructivist epistemology in different contexts. The black family is presented as one of such contexts. The study is further a demonstration of the role of a symptom as part of a recursive process of interaction in the context of a black family. It reflects an orientation rooted in cybernetics, ecology and systems theory. Therapy is presented as a context through which the therapist becomes incorporated and, therefore, adopting and speaking the language of the family's particular form of symptomatic communication in order to engender change. A literature study presenting a conceptual framework is presented. A case study presenting the research data is presented. Transcripts from video-taped sessions with the family are presented in the addendum. The implications of constructivist framework for the field of family therapy in the context of a black family are, therefore, outlined. / Social work / M.A. (Mental Health)
70

The self of the therapist as recursion : connecting the head and the heart

Valkin, Constance Beryl 12 1900 (has links)
The theoretical and methodological assumptions of this research imply a move away from a positivist empiricist approach with its reliance on the real, the measurable and the predictable towards an interactive and collaborative methodology situated in a constructivist and social epistemology. This thesis comprises a recursive intervention in the researching therapist's life. The author sets out on a voyage of self-research to investigate her "choreography of coexistence" (Maturana & Varela, 1987, p.248), due to curiosity about personal and professional impact. The purpose is to create a map of relational modes that in itself creates shifts: in the therapist. This invention-orientated research creates the context of the researcher and moves through processes: the writing of autobiography, detailed contextual description, the interpreting of feedback, and deconstruction. The contents that pour forth are many different narratives tracking the evolvement of the self in the original family, through further definition in new relationships and the expansion of roles in many professional systems both with clients and colleagues. " Extracts from conversations provide new perspectives and feedback about impact. Thus a continual 'provoking of voices' becomes a thesis theme that highlights the researcher's structure, organisation and interpersonal processes. An emancipatory and developmental process is documented through the researching therapist's positioning as actor, observer and then critic in relationship to the data. Patterns and themes emerge that facilitate both self- differentiation and connectedness and many new head-heart connections. This new knowledge could enable the professional's skilful and intuitive use of self. The self comes into being as it reflects itself, ·so a recursive process evolves where looking at the self operates on the products of its own operations. This is an active process, where the researching therapist constructs an experiential reality. Given the accountability that accrues from constructing such a reality, a focus on pragmatic, aesthetic and ethical criteria is incorporated. This research, like the practice of therapy, is a departure from attempts to demonstrate what is already known to modes of research that are recursive and improvisational. / Psychology / D. Litt. et Phil.

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