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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.
431

Konstruktionsintegrierte Optimierung mit intelligenten Bauteilfeatures im Dünnblechbereich

Krauß, Alexander, Fischer, Uwe 28 September 2017 (has links) (PDF)
Globalisierung, gestiegener Konkurrenzdruck und ein effektiver Einsatz von Ressourcen zwingen die Unternehmen – nicht nur in der Automobilindustrie – zu einer permanenten Effizienzsteigerung im Entwicklungsprozess. Um schnell das optimale Design zu finden, kommen CAD- und CAE- Programme in einer frühen Entwicklungsphase des Bauteils zum Einsatz. Durch eine virtuelle Überprüfung und Verbesserung z.B. von Funktion, Gewicht und Lebensdauer können kostenintensive Prototypen und Versuche erheblich minimiert werden. In der Automobilindustrie rücken zudem akustische Eigenschaften immer mehr in den Fokus. Ein geringes Innenraumgeräusch oder der spezielle »Sound« eines Fahrzeuges sind klassenspezifische Qualitätsmerkmale, welche die Kaufentscheidung des Kunden stark beeinflussen (Zeller 2009). Bei der Konstruktion von Karosseriebauteilen muss dabei besonderes Augenmerk auf die Vermeidung von Resonanzeffekten gelegt werden. Moderne CAD-Programme – wie CATIA V5® der Fairma Dassault – bieten bereits die Möglichkeit im CAD-Workflow Bauteileigenschaften zu ermitteln. Somit verschmelzen zunehmend die Grenzen zwischen Berechnung und Konstruktion. Allerdings setzt jeder Teilbereich Erfahrung und Expertenwissen voraus, wodurch immer noch eine entsprechende Kaskadierung der Aufgaben im Entwicklungsprozess zu finden ist. Diese wird nachstehend erläutert.
432

Analýza ručně psaného projevu u pacientů postižených neurologickými onemocněními / Analysis of hand-written text of patients with neurological disorders

Galáž, Zoltán January 2014 (has links)
The master‘s thesis deals with the analysis of the hand-written text. There is a design and a realization of a system for the purpose of diagnosing a Parkinson’s desease based on the analysis of hand-written text. The system consists from several modules and it is programmed in the programming environment of MATLAB. The first module provides pre-processing of the records to adjust records to the form suitable for the segmentation. Afterwards, the records are divided into those with signals onto the surface of the tablet and those with the signals above the surface of the tablet. In the next module the records are segmented by the two-phase metod of automatic segmentation.High-level featuresare calculated from the extracted features. The results of the statistical analysis are exported in the form suitable for the classification process. The classification is performed by the proposed model made in the programming environment of RapidMiner. The output of designed system is the trained model capable of automatic classification of the Parkinson’s disease by the analysis of the hand-written text.
433

A multiscale framework for affine invariant pattern recognition and registration

Rahtu, E. (Esa) 23 October 2007 (has links)
Abstract This thesis presents a multiscale framework for the construction of affine invariant pattern recognition and registration methods. The idea in the introduced approach is to extend the given pattern to a set of affine covariant versions, each carrying slightly different information, and then to apply known affine invariants to each of them separately. The key part of the framework is the construction of the affine covariant set, and this is done by combining several scaled representations of the original pattern. The advantages compared to previous approaches include the possibility of many variations and the inclusion of spatial information on the patterns in the features. The application of the multiscale framework is demonstrated by constructing several new affine invariant methods using different preprocessing techniques, combination schemes, and final recognition and registration approaches. The techniques introduced are briefly described from the perspective of the multiscale framework, and further treatment and properties are presented in the corresponding original publications. The theoretical discussion is supported by several experiments where the new methods are compared to existing approaches. In this thesis the patterns are assumed to be gray scale images, since this is the main application where affine relations arise. Nevertheless, multiscale methods can also be applied to other kinds of patterns where an affine relation is present. An additional application of one multiscale based technique in convexity measurements is introduced. The method, called multiscale autoconvolution, can be used to build a convexity measure which is a descriptor of object shape. The proposed measure has two special features compared to existing approaches. It can be applied directly to gray scale images approximating binary objects, and it can be easily modified to produce a number of measures. The new measure is shown to be straightforward to evaluate for a given shape, and it performs well in the applications, as demonstrated by the experiments in the original paper.
434

Gait and Tremor Monitoring System for Patients with Parkinson’s Disease Using Wearable Sensors

Perumal, Shyam Vignesh 15 April 2016 (has links)
Typically, a Parkinson’s disease (PD) patient would display instances of tremor and bradykinesia (slowness of movement) at an early stage of the disease and later develop gait disturbances and postural instability. So, it is important to measure the tremor occurrences in subjects to detect the onset of PD. Also, it is equally essential to monitor the gait impairments that the patient displays, as the order at which the PD symptoms appear in subjects vary from one to another. The primary goal of this thesis is to develop a monitoring system for PD patients using wearable sensors. To achieve that objective, our work focused first on identifying the most significant features that would best distinguish between PD and normal healthy subjects. Here, the various gait and tremor features were extracted from the raw data collected from the wearable sensors and further analyzed using statistical analysis and pattern classification techniques to pick the most significant features. In statistical analysis, the analysis of variance (ANOVA) test was conducted to differentiate the subjects based on the values of the mean. Further, pattern classification was carried out using the Linear Discriminant Analysis (LDA) algorithm. The analysis of our results shows that the features of heel force, step distance, stance and swing phases contributed more significantly to achieving a better classification between a PD and a normal subject, in comparison with other features. Moreover, the tremor analysis based on the frequency-domain characteristics of the signal including amplitude, power distribution, frequency dispersion, and median frequency was carried out to identify PD tremor from different types of artifacts.
435

Etude contrastive des créoles de la Jamaïque et de la Martinique / Contrastive approach of Jamaican and Martinican creole languages

Arsenec, Nicole 16 December 2015 (has links)
Motivée par Mervyn ALLEYNE (1980) qui met en évidence certaines spécificités des langues afro-américaines à bases lexicales différentes (verbes sériels, clivage du prédicat, TMA…), cette étude contrastive adopte une perspective synchronique d’un point de vue fonctionnel et structural afin d’établir les caractéristiques communes et les traits distinctifs des langues créoles de la Jamaïque (JC) et de la Martinique (CM) au-delà de leurs bases lexicales anglaise (CBLA) et française (CBLF). Les spécificités dégagées en JC & CM ne fonctionnent ni en anglais, ni en français, mais dans des créoles de part et d’autre de l’Atlantique quelle que soit leur base lexicale (CBLE, CBLP, CBLH). Elles se trouvent également dans certaines langues africaines du substrat. Selon la méthode comparative élaborée par OBENGA (1993) pour définir une famille de langues, la comparaison aborde les domaines phonétique, phonologique, syllabique, morphologique, syntaxique et sémantique afin d’évaluer des similitudes structurelles en JC & CM. Cette étude permet de conclure qu’il s’agit d’une nouvelle famille de langues pour lesquelles les langues européennes s’avèrent déterminantes au niveau lexical, les langues africaines étant essentielles au niveau des structures phonologique, prosodique, syllabique, sémantique et morphosyntaxique. / This contrastive approach was impulsed by Mervyn ALLEYNE (1980) who pointed out, « Some Similarities of Afro-American » regardless of lexifier, like serial verbs, topicalization, TMA verbal system…In a synchronic perspective, the purpose of this research is to estabish structural and functional similarities between Jamaican Creole (JC) based on English lexicon (CBEL) and Martinican Creole (CM) based on French lexicon (CBFL) in order to identify distinctive features of Creole Languages.After a survey of the linguistic fields according to the method to determine a family of languages of Theophile OBENGA (1993), it becomes obvious that these specific structures are more than similar in these two Afro-American languages.Opposed to flexional languages like English and French, widely spread in West African languages, these characteristics are functioning in Creole Languages on both sides of the Atlantic Ocean, and can be considered as distinctive features. In this new family of languages, European languages are decisive at a lexical level, while African languages are essential for phonemic, prosodic, syllabic, semantic and morphosyntactic structures.
436

Autonomous facial expression recognition using the facial action coding system

de la Cruz, Nathan January 2016 (has links)
>Magister Scientiae - MSc / The South African Sign Language research group at the University of the Western Cape is in the process of creating a fully-edged machine translation system to automatically translate between South African Sign Language and English. A major component of the system is the ability to accurately recognise facial expressions, which are used to convey emphasis, tone and mood within South African Sign Language sentences. Traditionally, facial expression recognition research has taken one of two paths: either recognising whole facial expressions of which there are six i.e. anger, disgust, fear, happiness, sadness, surprise, as well as the neutral expression; or recognising the fundamental components of facial expressions as defined by the Facial Action Coding System in the form of Action Units. Action Units are directly related to the motion of specific muscles in the face, combinations of which are used to form any facial expression. This research investigates enhanced recognition of whole facial expressions by means of a hybrid approach that combines traditional whole facial expression recognition with Action Unit recognition to achieve an enhanced classification approach.
437

Implication relative des traits de haut niveau et de bas niveau des stimuli dans la catégorisation, chez l'homme et le singe / Relative contribution of low level and high level features of stimuli in categorization in humans and monkeys

Collet, Anne-Claire 12 February 2016 (has links)
Dans cette thèse, nous nous sommes proposé d'explorer les contributions relatives des caractéristiques de haut et de bas niveau des stimuli dans la catégorisation d'objet. Ce travail comporte trois études, chez l'homme et le singe. L'originalité de cette thèse réside donc dans la construction des stimuli. Notre première étude a visé à caractériser les corrélats neuraux de la reconnaissance d'images chez le singe en ECoG. Pour cela nous avons développé un protocole de catégorisation où les stimuli étaient des séquences visuelles dans lesquelles les contours des objets (information sémantique, caractéristique de haut niveau) étaient modulés cycliquement grâce à la technique SWIFT (créée par Roger Koenig et Rufin VanRullen) alors que la luminance, les contrastes et les fréquences spatiales (caractéristiques de bas niveau) étaient conservées. Grâce à une analyse en potentiels évoqués, nous avons pu mettre en évidence une activité électrophysiologique tardive en " tout ou rien " spécifique de la reconnaissance de la cible de la tâche par le singe. Mais parce que les objets sont rarement isolés en conditions réelles, nous nous sommes penchés dans une deuxième étude sur l'effet de congruence contextuelle lors de la catégorisation d'objets chez l'homme et le singe. Nous avons comparé la contribution du spectre d'amplitude d'une transformée de Fourier à cet effet de congruence chez ces deux espèces. Nous avons révélé une divergence de stratégie, le singe semblant davantage sensible à ces caractéristiques de bas niveau que l'homme. Enfin dans une dernière étude nous avons tenté de quantifier l'effet de congruence sémantique multisensorielle dans une tâche de catégorisation audiovisuelle chez l'homme. Dans cette étude nous avons égalisé un maximum de paramètres de bas niveau dans les deux modalités sensorielles, que nous avons toujours stimulées conjointement. Dans le domaine visuel, nous avons réutilisé la technique SWIFT, et dans le domaine auditif nous avons utilisé une technique de randomisation de snippets. Nous avons pu alors constater un gain multisensoriel important pour les essais congruents (l'image et le son désignant le même objet), s'expliquant spécifiquement par le contenu sémantique des stimuli. Cette thèse ouvre donc de nouvelles perspectives, tant sur la cognition comparée entre homme et primate non humain que sur la nécessité de contrôler les caractéristiques physiques de stimuli utilisés dans les tâches de reconnaissance d'objets. / In this thesis, we explored the relative contributions of high level and low level features of stimuli used in object categorization tasks. This work consists of three studies in human and monkey. The originality of this thesis lies in stimuli construction. Our first study aimed to characterize neural correlates of image recognition in monkey, using ECoG recordings. For that purpose we developped a categorization task using SWIFT technique (technique created by Roger Koenig and Rufin VanRullen). Stimuli were visual sequences in which object contours (semantic content, high level feature) were cyclically modulated while luminance, contrasts and spatial frequencies (low level features) remained stable. By analyzing evoked potentials, we brought to light a late electrophysiological activity, in an " all or none " fashion, specifically related to the target recognition in monkey. But because in real condition objects are never isolated, we explored in a second study contextual congruency effect in visual categorization task in humans and monkeys. We compared the contribution of Fourier transform amplitude spectrum to this congruency effect in the both species. We found a strategy divergence showing that monkeys were more sensitive to the low level features of stimuli than humans. Finally, in the last study, we tried to quantify multisensory semantic congruency effect, during a audiovisual categorization task in humans. In that experiment, we equalized a maximum of low level features, in both sensory modalities which were always jointly stimulated. In the visual domain, we used again the SWIFT technique, whereas in auditory domain we used a snippets randomization technique. We highlighted a large multisensory gain in congruent trials (i.e. image and sound related to the same object), specifically linked to the semantic content of stimuli. This thesis offers new perspectives both for comparative cognition between human and non human primates and for the importance of controlling the physical features of stimuli used in object recognition tasks.
438

An analysis of the metrical and morphological features of South African black males for the purpose of facial identification

Roelofse, M.M. (Michelle Marizan) 10 May 2007 (has links)
See Abstract on Page 3 of declaration: / Dissertation (MSc (Anatomy))--University of Pretoria, 2007. / Anatomy / unrestricted
439

Cremnophilous succulents of southern Africa : diversity, structure and adaptations

Van Jaarsveld, Ernst Jacobus 29 May 2012 (has links)
The vertical cliff-face habitat is renowned for many specifically adapted plant species that exhibit a high degree of local endemism. Over a period of nine years the succulents and bulbous succulents on cliff faces in South Africa and Namibia were systematically surveyed and documented. Distinction was made between succulents growing on cliffs as part of a wider habitat and those found only on cliffs (obligate cremnophytes). Most major cliff-face habitats in the study area were visited and all plants were documented. A check list and descriptions (including adaptive traits) of the 220 obligate cremnophilous taxa are provided. During the study some 45 new cremnophilous succulent taxa were discovered and named, representing almost 20% of the total and proving that cliff habitats are some of the least studied environments, not only in southern Africa but globally. Among the newly described cremnophilous taxa is the genus Dewinteria (Pedaliaceae). Using stem length, three basic cliff-face growth forms are identified - compact or cluster-forming ‘cliff huggers’, cliff shrublets or ‘cliff squatters’ and pendent ‘cliff hangers’. Compact growth (often tight clusters or mats) is mainly associated with the winter-rainfall Succulent Karoo and Thicket regions, especially Namaqualand. However, further north the same compact growth forms are associated with an increase in altitude such as the Drakensberg Escarpment and other northern mountains. Most pendent growth forms are associated with the eastern and southeastern summer-rainfall regions; a number of smaller pendent shrublets occur on the high quartzitic sandstone mountains of the Western Cape. The degree of specialisation varies from highly adapted (smaller percentage) to less specialised (often eco-forms), and some taxa have no obvious adaptations. This study revealed a general increase in succulence in most obligate cremnophilous succulent species (compared to closely related species in other habitats), a reflection of their xeric habitat, and plants tend to be more compact. Also, there is a shift in reproductive output, including an increase in vegetative reproduction (backup), wind-dispersed seed and enriched flowering associated with certain species. Most obligate cremnophilous succulent plants in the study area have cliff-adapted features, ensuring long-term survival. / Thesis (PhD)--University of Pretoria, 2012. / Plant Science / unrestricted
440

Kgegeo Dingwalong Tša Sepedi (Sepedi)

Maruma, Mamalatswa Walburga 16 June 2012 (has links)
In Sepedi, there is a problem of using irony instead of satire in reference to literary genres. The difference between the two concepts is that irony is a figure of speech and satire is a text type. To bring clarity on this issue, an attempt was made to give a thorough explanation of these concepts. In addition to this, emphasis was on the indication of how irony is employed in writing satire , explanation of structure of genres classified as irony, the correct name for such writings and an indication of how style differentiates those genres. Satire as a literary genre, like moral and didactical narratives has the aim of exposing evil in the society. In the light of this, an attempt was made to differentiate between satire as a literary genre and as a didactical narrative. In an attempt to clarify this, use was made of narratological model which emphasises content, plot and style in genre analysis. Irony as a figure of speech is embedded in the analysis of style in a text. This implies contrast which may be vertical or horizontal, depending on the position of words, sentences or morphemes in a sentence. When used vertically, it gives a meaning different from the reality, thus saying the opposite of what one means. To give a thorough explanation of the concept of satire, it was differentiated from moral stories by using two short stories namely, ‘Nna nka se je dipute…’ from Mantšhaotlogele (1985) by S.N. Nkadimeng and ‘Nka se sa boeletša’ from Medupi ya megokgo (1985) by D.L.M Mpepele. The two short stories were preferred in this study because of remarkable resemblances in respect of their content. They both outline the conflict between the child and a parent and they are similar in setting and milieu. The differences of these concepts as outlined in the summary of this work lies in their style. In his work, Nkadimeng stated the conflict in such a way that it is resolved by introducing a new character, the father in this case, who seemed to be passive all along. He intervenes in the conflict to act as the conscience of the mother, jolting her to her senses on time. Nkadimeng’s style is cool and calm, thus creates a pleasant atmosphere. Mpepele outlined the conflict until the parent acknowledges his wrong behaviour and confesses that he will never do it again. The father thus learned a hard way. Mpepele’s style is sharp, self – biting and spells out venom which effectively intercepts the lesson the father must learn. / Thesis (DLitt)--University of Pretoria, 2012. / African Languages / unrestricted

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