Dissertation (PhD)--Stellenbosch University, 2000. / ENGLISH ABSTRACT: The use of helicopters has become almost universally accepted as the method of choice in the enumeration of large ungulates in Southern Africa. In most cases decisions affecting management of these populations are made based on a single count result. In all these instances the within technique variance is ignored, often leading to decisions based on type I or type II statistical errors where the within technique variance is misconstrued as the population change. Many studies have investigated the issue of accuracy of counting methods and a few have quoted precision values for various methods. Very few have, however, investigated power and those extant have approached the problem from a prospective point of view and predicted power values. This study has made use of replicated counts from 12 sites of the original 23 in four vegetation types of the then Transvaal Province. The study sites vary in terms of size and all counts were undertaken with an experienced, trained team in which only four observers were used. A comprehensive post hoc analysis of the results of the field surveys shows precision and power to vary widely according to species and vegetation type and concludes that gamecounting results are largely site specific. A decline in observations during the course of four hours of survey is demonstrated and although the exact cause cannot be determined, correction factors have been constructed for two vegetation types. Observers are shown to differ from one another in observation profile during the course of surveys. This study demonstrates, describes and quantifies the existence of several phenomena suspected to exist by experienced game counters, biologists and wildlife managers and makes proposals in terms of improving the data returned from expensive aerial surveys. / AFRIKAANSE OPSOMMING: In Suider-Afrika word die gebruik van 'n helikopter vir die tel van hoefdiere byna algemeen aanvaar as die metode wat voorkeur geniet. In meeste gevalle word besluitnemings rakende die bestuur van hierdie populasies gebaseer op die resultate van 'n enkele telling. In al die gevalle word tegniekverwante afwykings buite rekening gelaat en dit het die gevolg dat bestuursbesluite gebaseer word op tipe I en tipe II statistiese foute, en dit lei weer op hulle beurt dat tegniekverwante afwykings verkeerdelik geïnterpreteer word as die rede vir veranderings in die bevolkings. Verskeie studies het al die feitegeskil omtrent die akkuraatheid van telmetodes ondersoek en sommige het herhaalbaarheidswaardes vir die verskillende metodes aangehaal. Baie min het egter statistiese mag ondersoek en die wat dit wel gedoen het, het prospektiewe magsanalise as uitgangspunt gebruik en statistiese magwaardes voorspelom die probleem aan te spreek. Hierdie studie het gebruik gemaak van herhaalde tellings van 12 gebiede uit die oorspronklike 23 in vier veldtipes geleë in die ou Transvaal Provinsie. Die studiegebiede verskil in groottes. Alle tellings is deur 'n bekwaamde opgeleide span gedoen wat slegs vier waarnemers ingesluit het. 'n Omvattende post hoc analise van die resultate van die veldopnames dui aan dat herhaalbaarheid en statistiese mag baie varieer met betrekking tot spesies en veldtipes en word die gevolgtrekking gemaak dat wildtellingsresultate grootliks gebiedsgebonde is. In Afname in waarnemings gedurende die verloop van In vier uuropname, is waargeneem en alhoewel die ware oorsaak nie vasgestel kan word nie, is korreksiefaktore bereken vir twee veldtipes. Dit blyk dat waarnemers van mekaar verskil het met betrekking tot hul waarnemingsprofiele gedurende die verloop van die opnames. Hierdie studie dui aan, beskryf en kwantifiseer die bestaan van verskeie verskynsels wat vermoedelik bestaan het by ervare wildtelIers, bioloë en wildlewebestuurders en maak voorstelle met betrekking tot die verbetering van data wat tydens duur lugopnames ingesamel word.

No abstract available. / Thesis (M.Env.Dev.)-University of Natal, Pietermaritzburg, 2003.

A contagem de células vermelhas do sangue desempenha um papel importante no diagnóstico de animais silvestres e domésticos. Apesar da existência de muitas tecnologias em diferentes contadores automatizados para análise de sangue, quando se trata do sangue de animais silvestres ainda é difícil encontrar uma solução simples e economicamente viável para múltiplas espécies. O objetivo deste estudo é desenvolver um contador automático de células vermelhas. Amostras de sangue (1 jaguatirica - Leopardus pardalis, 1 macaco - Cebus apella, 1 quati - Nasua nasua, 62 cães - Canis familiaris e 5 cavalos - Equus caballus) foram analisadas usando três métodos: 1-contagem manual, 2-contagem automática por imagem e 3-contagem semiautomática por imagem; as amostras de cães e cavalos foram analisadas por um quarto método: 4-contagem automática por impedância. As contagens dos métodos 2 e 3 foram obtidas usando o contador de células vermelhas proposto. Os resultados foram comparados usando a correlação de Pearson e gráficos com diferentes métodos como valor de referência. As contagens dos métodos 1, 2 e 3 correlacionaram muito bem com as contagens do método 4 (r ≥ 0.94). As contagens produzidas pelo método 2 apresentaram alta correlação com o método 3 (r = 0.998). Os resultados indicam que o contador proposto pode ser usado como um método de contagem automática ou semiautomática em clínicas que usam o método manual para contagem de células vermelhas do sangue de animais. / A RBC count plays an important role in the diagnostic of wild and domestic animals. Despite the many technologies available in different automated hematology analyzers, when it comes to blood of wild animals it is still difficult to find an easy and affordable solution for multiple species. This study aims to develop an automatic red blood cell counter. Blood samples (1 ocelot - Leopardus pardalis, 1 monkey - Cebus apella, 1 coati - Nasua nasua, 62 dogs - Canis familiaris and 5 horses - Equus caballus) were analyzed using three methods: 1-manual count, 2automatic count by image and 3-semi-automatic count by image; blood from dogs and horses were also analyzed by a fourth method: 4-automatic count by impedance. The counts of methods 2 and 3 were produced by the proposed red blood cell counter. Results were compared using Pearson’s correlation and plots with different methods as the criterion standard. RBC counts of methods 1, 2 and 3 correlated very well with those on the method 4 (r ≥ 0.94). RBC counts produced by method 2 were highly correlated with method 3 (r = 0.998). The results indicate that the proposed method can be used as an automatic or semi-automatic counting method in clinics that are currently using the manual method for RBC assessment.

Le comptage des points rationnels est un problème classique en géométrie diophantienne. On s’intéresse à des majorations du nombre des points rationnels de hauteur bornée qui sont valables pour toute hypersurface arithmétique de degré fixé d’un espace projectif. Dans ce but, on construit une famille d’hypersurfaces auxiliaires qui contiennent tous les points rationnels de hauteur bornée mais ne contiennent pas le point générique de l’hypersurface initiale. Plusieurs outils géométriques sont développés ou adaptés dans le cadre de la géométrie d’Arakelov et de la géométrie diophantienne afin d’appliquer la méthode des déterminants par la langage de la géométrie d’Arakelov, notamment une majoration et une minoration explicite uniforme de la fonction de Hilbert-Samuel arithmétrique d’une hypersurface. Pour un schéma projectif réduit de dimension pure sur un anneau d’entiers algébriques, on donne une majoration du nombre des places sur lesquelles la fibre ne soit pas réduite. Cette majoration est utile pour la construction des hypersurfaces auxiliaires mentionnées au-dessus. De plus, la géométrie sur un corps fini joue un rôle important dans ce problème. Dans ce travail, l’un des ingrédients clé dans ce travail est une majoration effective liée à une fonction de comptage des multiplicités des points rationnels dans une hypersurface projective réduite définie sur un corps fini, qui donne une description de la complexité de son lieu singulier. Pour ce problème de comptage de multiplicités, l’outil principal est la théorie d’intersection sur un espace projectif. / Counting rational points is a classical problem in Diophantine geometry. We are interested inupper bounds for the number of rational points of bounded height of an arithmetic hypersurface with bounded degree in a projective space. For this propose, we construct a family of auxiliary hypersurfaces which contain all these rational points of bounded height but don’t contain the generic point of this hypersurface. Several tools of Arakelov geometry and Diophantine geometry are developed or adapted in this work in order to apply the determinant method by the approach of Arakelov geometry, especially a uniform explicit upper bound and a uniform explicit lower bound of the arithmetic Hilbert-Samuel function of a hypersurface. For a reduced pure dimensional projective scheme over a ring of algebraic integers, we give an upper bound of the number of places over which the fiber is not reduced any longer. This upper bound is useful for the construction of these auxilary hypersurfaces mentioned above. In addition, the geometry over a finite field plays an important role in this problem. One of the key ingredients in this work is an e_ective upper bound for a counting function of multiplicities of rational points in a reduced projective hypersurface defined over a finite field, which gives a description of the complexity of its singular locus. For this problem of counting multiplicities, the major tool is intersection theory on a projective space

Vyhledávání regulárních výrazů má ve vývoji softwaru nezastupitelné místo. Rychlost vyhledávání může ovlivnit použitelnost softwaru, a proto je na ni kladen velký důraz. Pro určité druhy regulárních výrazů mají standardní přístupy pro vyhledávání vysokou složitost. Kvůli tomu jsou náchylné k útokům založeným na vysoké náročnosti vyhledávání regulárních výrazů (takzvané ReDoS útoky). Regulární výrazy s omezeným opakováním, které se v praxi často vyskytují, jsou jedním z těchto druhů. Efektivní reprezentace a rychlé vyhledávání těchto regulárních výrazů je možné s použítím automatu s čítači. V této práci představujeme implementaci vyhledávání regulárních výrazů založeném na automatech s čítači v C++. Vyhledávání je implementováno v rámci RE2, rychlé moderní knihovny pro vyhledávání regulárních výrazů. V práci jsme provedli experimenty na v praxi používaných regulárních výrazech. Výsledky experimentů ukázaly, že implementace v rámci nástroje RE2 je rychleší než původní implementace v jazyce C#.

Fatigue analysis is a critical stage in the design of any structural component. Typically fatigue is analysed during post-processing, but as the size of the analysed component increases, the amount of data stored for the analysis increases simultaneously. This increases the computational and memory requirements of the system, intensifying the work load on the engineer. A continuum mechanics approach namely ’Continuous time fatigue model’, for fatigue analysis is available in a prior study which reduces the computational requirements by simultaneously computing fatigue along with the stress. This model implements a moving endurance surface in the stress space along with the damage evolution equation to compute high-cycle fatigue. In this thesis the continuous time fatigue model is compared with conventional model (ie.Cycle counting) to study its feasibility. The thesis also aims to investigate the continuous time fatigue model and an evolved version of the model is developed for non-proportional load cases to identify its limitations and benefits.

L'un des objectifs centraux de la biologie est de comprendre comment l'ADN, la séquence primaire, donne lieu à des traits observables. À cette fin, nous examinons ici des méthodes pour identifier les composants génétiques qui influencent les traits microbiens. Par « identifier », nous entendons l'élucidation à la fois l'état allélique et de la position physique de chaque variante causale d'un phénotype d'intérêt à la résolution des nucléotides de paires de bases. Nous nous sommes concentrés sur les études d'association génomique (genome-wide association studies; GWAS) en tant qu'approche générale d’étudier l'architecture génétique des traits. L'objectif global de cette thèse était d'examiner de manière critique les méthodologies GWAS et de les considérer en pratique dans des populations microbiennes fortement clonales et non- clonales (i.e. avec recombinaison fréquent). Le domaine de la GWAS microbienne est relativement nouveau par rapport aux quinze dernières années de la GWAS humaine, et en tant que tel, nous avons commencé par un examen de l'état de la GWAS microbienne. Nous avons posé deux questions principales : 1) Les méthodes GWAS humaines fonctionnent-elles facilement et sans modification pour les populations microbiennes ? 2) Et sinon, quels sont les problèmes méthodologiques centraux et les modifications nécessaires pour la GWAS microbienne? À partir de ces résultats, nous avons ensuite détaillé le déséquilibre de liaison (linkage disequilibrium; LD) comme principal obstacle dans la GWAS microbien, et nous avons présenté une nouvelle méthode, POUTINE, pour relever ce défi en exploitant les mutations homoplasiques pour briser implicitement la structure LD. Le reste de la thèse présente à la fois les méthodes traditionnelles GWAS (comptage des allèles) et POUTINE (comptage d’homoplasies) appliquées à une population hautement recombinogène de génomes de vibrions marins. Malgré une taille d'échantillon modeste, nous donnons un premier aperçu de l'architecture génétique de la résistance aux bactériophages dans une population naturelle, tout en montrant que les récepteurs des bactériophages jouent un rôle primordial. Ce résultat est en pleine cohérence avec des expériences en laboratoire de coévolution phage-bactérie. Il est important de noter que cette architecture met en évidence à quel point la sélection positive peut sculpter certains traits microbiens différemment de nombreux traits complexes humains, qui sont généralement soumis à une faible sélection purificatrice. Plus précisément, nous avons identifié des mutations à effet important à haute fréquence qui sont rarement observées dans les phénotypes complexes humains où de nombreuses mutations à faible effet contribuent à l'héritabilité. La thèse se termine par des perspectives sur les voies à suivre pour la GWAS microbienne. / One of the central goals of biology is to understand how DNA, the primary sequence, gives rise to observable traits. To this aim, we herein examine methods to identify the genetic components that influence microbial traits. By "identify" we mean the elucidation of both the allelic state and physical position of each causal variant of a phenotype of interest down to the base-pair nucleotide resolution. Our focus has been on genome-wide association studies (GWAS) as a general approach to dissecting the genetic architecture of traits. The overarching aim of this thesis was to critically examine GWAS methodologies and to consider them in practice in both strongly clonal and highly recombining microbial populations. The field of microbial GWAS is relatively new compared to the over fifteen years of human GWAS, and as such, we began this work with an examination of the state of microbial GWAS. We asked and attempted to answer two main questions: 1) Do human GWAS methods readily work without modification for microbial populations? 2) And if not, what are the central methodological problems and changes that are required for a successful microbial GWAS? Building from these findings, we then detailed linkage disequilibrium (LD) as the primary obstacle in microbial GWAS, and we presented a new method, POUTINE, to address this challenge by harnessing homoplasic mutations to implicitly break LD structure. The remainder of the thesis showcases both traditional GWAS methods (allele counting) and POUTINE applied to a highly recombining population of marine vibrio genomes. Despite a small sample size, we provide a first glimpse into the genetic architecture of bacteriophage resistance in a natural population and show that bacteriophage receptors play a primary role consistent with experimental populations of phage-bacteria coevolution. Importantly, this architecture highlights how strong positive selection can sculpt some microbial traits differently than many human complex traits, which are generally under weak purifying selection. Specifically, we identified common frequency, large-effect mutations that are rarely observed in human complex phenotypes where many low-effect mutations are thought to contribute to the bulk of heritability. The thesis concludes with perspectives on ways forward for microbial GWAS.

Relational data is characterised by the rich structure it encodes in the dependencies between the individual entities of a given domain. Statistical Relational Learning (SRL) combines first-order logic and probability to learn and reason over relational domains by creating parametric probability distributions over relational structures. SRL models can succinctly represent the complex dependencies in relational data and admit learning and inference under uncertainty. However, these models are significantly limited when it comes to the tractability of learning and inference. This limitation emerges from the intractability of Weighted First Order Model Counting (WFOMC), as both learning and inference in SRL models can be reduced to instances of WFOMC. Hence, fragments of first-order logic that admit tractable WFOMC, widely known as domain-liftable, can significantly advance the practicality and efficiency of SRL models. Recent works have uncovered another limitation of SRL models, i.e., they lead to unintuitive behaviours when used across varying domain sizes, violating fundamental consistency conditions expected of sound probabilistic models. Such inconsistencies also mean that conventional machine learning techniques, like training with batched data, cannot be soundly used for SRL models. In this thesis, we contribute to both the tractability and consistency of probabilistic inference in SRL models. We first expand the class of domain-liftable fragments with counting quantifiers and cardinality constraints. Unlike the algorithmic approaches proposed in the literature, we present a uniform combinatorial approach, admitting analytical combinatorial formulas for WFOMC. Our approach motivates a new family of weight functions allowing us to express a larger class of probability distributions without losing domain-liftability. We further expand the class of domain-liftable fragments with constraints inexpressible in first-order logic, namely acyclicity and connectivity constraints. Finally, we present a complete characterization for a statistically consistent (a.k.a projective) models in the two-variable fragment of a widely used class of SRL models, namely Markov Logic Networks.

International Telemetering Conference Proceedings / November 04-07, 1991 / Riviera Hotel and Convention Center, Las Vegas, Nevada / On the disscussion of custom real-time counting-measuring method, this paper presents a new method suitable for the working condition of non-man duty, which possesses the feature of 100ns counting-measuring accuracy and high fidelity. In addition, the concept of “Signal-time/digit converter” is proposed for the first time and the principle and working procedure of this method are introduced in brief.

We consider random fractals generated by random recursive constructions, prove zero-one laws concerning their dimensions and find their packing and Minkowski dimensions. Also we investigate the packing measure in corresponding dimension. For a class of random distribution functions we prove that their packing and Hausdorff dimensions coincide.