京都大学 / 新制・課程博士 / 博士(工学) / 甲第23883号 / 工博第4970号 / 新制||工||1776(附属図書館) / 京都大学大学院工学研究科機械理工学専攻 / (主査)教授 蓮尾 昌裕, 教授 鈴木 基史, 教授 江利口 浩二 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

Classical orthogonal and oblique cutting are the fundamental material removal or machining processes to which other practical machining processes can be related in the study and modelling of the machining processes. In the last century, a large amount of research and development work has been done to study and understand the various machining processes with a view to improving the processes for further economic (cost and productivity) gains. However, many aspects of the cutting processes and cutting performance remains to be fully understood in order to increase the cutting capability and optimize the cutting processes; in particular, there is little study to understand the effects of the inevitable tool wear on the machining processes. This thesis includes an extensive literature review on the mechanics of cutting analysis. Considerable work has been carried out in past decades on the fundamental analysis of 'sharp' tool cutting. Although some work has been reported on the effects of tool flank wear on the cutting performance, there is a general lack of the fundamental study of the effects of the flank wear on the basic cutting or chip formation process. It has been well documented that tool flank wear results in an increase in the cutting forces. However, it was not known if this force increase is a result of the change in the chip formation process, and/or the rubbing or ploughing forces between the tool flank and the workpiece. In work carried out since the early 1980s, the effects of the so-called edge forces have been considered when the tool is not absolutely sharp. Little has been reported to further develop fundamental cutting theories to understand applications to more relevant the practical situation, i.e. to consider the tool wear effects. Based on the findings of the literature review, an experimental investigation is presented in the first part of the thesis to study the effects of tool flank wear on the basic cutting or chip formation process by examining the basic cutting variables and performance in the orthogonal cutting process with tool flank wear. The effects of tool flank wear on the basic cutting variables are discussed by a comprehensive analysis of the experimental data. It has been found that tool flank wear does not affect the basic cutting variables (i.e. shear angle, friction angle and shear stress). It is therefore deduced that the flank wear does not affect the basic chip formation process in the shear zone and in the tool-chip interface. The study also finds that tool flank wear causes an increase in the total cutting forces, as can be expected and such an increase is entirely a result of the rubbing or ploughing forces on the tool wearland. The significance of this finding is that the well-developed machining theories for 'sharp' tools can be used in modelling the machining processes when tool flank wear is present, rather than study the machining process and develop machining theories from scratch. The ploughing forces can be modelled for incorporation into the overall cutting force prediction. The experimental study also allows for the forces on the wearland (or wearland force) and edge forces to be separated from the total measured forces. The wearland force and edge force models are developed in empirical form for force prediction purpose. In addition, a database for the basic cutting variables or quantities is established for use in modelling the cutting forces. The orthogonal cutting force model allowing for the effects of flank wear is developed and verified by the experimental data. A comprehensive analysis of the mechanics of cutting in the oblique cutting process is then carried out. Based on this analysis, predictive cutting force models for oblique cutting allowing for the effects of flank wear are proposed. The wearland force and edge force are re-considered by analysing the oblique cutting process and the geometrical relation. The predictive force models are qualitatively and quantitatively assessed by oblique cutting tests. It shows that the model predictions are in excellent agreement with the experimental data. The modelling approach is then used to develop the cutting force models for a more general machining process, turning operation. By using the concept of an equivalent cutting edge, the tool nose radius is allowed for under both orthogonal and oblique cutting conditions. The wearland forces and edge forces are taken into consideration by the integration of elemental forces on the tool flank and the cutting edge, respectively. The cutting forces in turning operations are successfully predicted by using the basic cutting quantity database established in the orthogonal cutting analysis. The models are verified by turning operation tests. It shows that the model predictions are in excellent agreement with the experimental results both qualitatively and quantitatively. The major findings, research impacts and practical implications of the research are finally highlighted in the conclusion. The modelling approach considering the flank wear effects in the classical orthogonal and oblique cutting and turning operations can be readily extended to other machining operations, such as drilling and milling.

Image processing plays a key role in vision systems. Its function is to extract and enhance pertinent information from raw data. In robotics, processing of real-time data is constrained by limited resources. Thus, it is important to understand and analyse image processing algorithms for accuracy, speed, and quality. The theme of this thesis is an implementation and comparative study of algorithms related to various image processing techniques like edge detection, corner detection and thinning. A re-interpretation of a standard technique, non-maxima suppression for corner detectors was attempted. In addition, a thinning filter, Hall-Guo, was modified to achieve better results. Generally, real time data is corrupted with noise. This thesis also incorporates few smoothing filters that help in noise reduction. Apart from comparing and analysing algorithms for these techniques, an attempt was made to implement correlation-based optic flow

Thesis (Ph. D.)--University of Washington, 1997. / Vita. Includes bibliographical references (p. [153]-167).

Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2011. / ENGLISH ABSTRACT: This thesis forms part of the Control Surfaces in Confined Spaces (CoSICS) project conducted at Stellenbosch University. The aim of this project is reduction of control surface actuator footprints on the existing wing structures of commercial airliners such as the Airbus A320 and A330. This is achieved by reducing control surface hinge moments through the application of trailing edge tabs. This results in smaller actuator requirements. The first tier of the project focussed on the geometric optimisation of the tab applied to an aileron. This thesis focusses on the development of dynamic control of the aileron through either tab-only or concurrent tab and aileron actuation. In the effort to develop dynamic control, a fully coupled generalised dynamic model of the tab and aileron is derived and presented. Through linearisation of this model, linear controllers are developed. Two distinctly different controllers are presented; the first controller makes use of classical methods for control of the tab-only actuated aileron and the second controller makes use of modern control techniques such as full state feedback to facilitate controlled concurrent tab and aileron actuation. Each proposed controller is evaluated in terms of dynamic performance, robustness, disturbance rejection and noise immunity. Based on the controller development, a summary of dynamic actuator requirements is given. Practical verification of the model and the controller performance is then undertaken. The development of the necessary hardware and software is also presented. The concept of aileron control through tab-only actuation and concurrent tab and aileron actuation is then validated. Conclusion are then drawn about the accuracy of the theoretical model and the practical performance of the controllers. The thesis is concluded with recommendations for future work to increase the fidelity of the model. Important aspects about the practical implementation of the concept on commercial jetliners are also summarised. / AFRIKAANSE OPSOMMING: Hierdie tesis is deel van die Control Surfaces in Confined Spaces1 projek by Stellenbosch Universiteit. Die doel van hierdie projek behels die verkleining van die aktueerder spasie en ondersteunings struktuur vereistes, op die bestaande vlerk struktuur van kommersiële vliegtuie soos die Airbus A320 en Airbus A330. Dit is bereik deur die vermindering van die beheeroppervlak skarnier se draaimoment met behulp van aerodinamiese hulpvlakke. Kleiner aktueerders word dus benodig. Die eerste stadium van die projek fokus op die geometriese optimisering van die hulpvlak op ’n aileron. Hierdie tesis fokus op die ontwikkeling van dinamiese beheer van die aileron deur middel van hulpvlak aktueering alleenlik of met die gelyktydige aktueering van die hulpvlak en aileron. In die proses van onwikkeling is ’n volgekoppelde veralgemeende dinamiese model van die hulpvlak en aileron afgelei en voorgelê. Deur middel van linearisasie van die model is linieêre beheerders ontwikkel. Tans is twee verskillende beheerders ontwikkel. Die eerste beheerder is gebaseer op die klassieke metodes en maak staat op die aktueering van die hulpvlak alleenlik. Die tweede beheerder maak gebruik van moderne beheer tegnieke soos vol toestand terugvoer om gelyktydige hulpvlak en aileron aktueering te realiseer. Die beheerders is elk geëvalueer in terme van dinamiese gedrag, robuustheid, versteurings verwerping en ruis verwerping. Die beheerstelsel ontwikkeling lei tot ’n opsomming van die dinamiese aktueerder vereistes. Dit word gevolg deur praktiese verifikasie van die model en die beheerstelsel gedrag. ’n Opsomming van die ontwikkeling van nodige hardeware en sagteware word voorgelê. In hierdie proses is die konsep van beide hulpvlak alleenlike aktueering en gelyktydige hulpvlak en aileron aktueering bewys. Gevolgtrekkings word gemaak oor die akkuraatheid van die model en die praktiese gedrag van die beheerders. Die tesis word afgerond met voorstelle vir toekomstige werk wat die model se betroubaarheid kan verbeter. Verder word belangrike punte oor die praktiese aspekte van konsep implementering op kommersiële vliegtuie ook uitgelig.

Thesis (MScFor)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: One of the major objectives in plantation forestry is to achieve a high level of homogeneity of distribution and dimension of trees within the stand. Precise planting geometries, intensive silviculture and genetic selection are used to achieve this homogeneity. However, a natural variability is still introduced by micro-­‐site conditions and disturbances. A substantial source of variation is caused by edge effects of neighbouring stands or other land use forms. The edge effect causes trees at the stand edge to develop differently from trees in the interior of the stand. The overarching objective of this study is to simulate the edge effect based on average stand interior variables as typically received from an enumeration and spatial information on the current and historic stand neighbourhood. With re-­‐introducing this natural variance as well as its spatial pattern, we expect to derive improved planning information. A major aim is thus separating the effect of the edge interaction from the other factors contributing to stand variance and quantifying the result in terms of stand output. A methodology is introduced for quantifying interaction at stand edges between a given stand and its neighbouring stands over its lifetime. Transferring the edge interaction value from the edges to all the trees within the stand is then done by applying inverse distance weighting interpolation from the edges to the tree position within the stand. Once an edge interaction value has been calculated for each point, the extent of the edge effect is quantified. The spatial extent of the edge effect is derived empirically from an existing fully spatially mapped stand by means of breakpoint regression. The expected variance as a result of edge influence is then quantified by producing a set of models, which can reproduce the effect of the edge interaction on tree height, diameter and volume. The edge effect is treated as a dynamic interaction for which the temporal aspect needs to be considered, because the current spatial structure of a stand is influenced by its current neighbourhood, but also by the historic development of the neighbourhood in relation to the stand in question. Each stand therefore undergoes an edge effect which is completely unique to that stand, within a given time period. For this reason the presented methodology is a spatial-­‐temporal one, aimed at providing a way in which growth and yield forest modelling can be augmented by the inclusion of the edge effect in a practical way. To explicitly quantify edge effects, the natural variance had to be separated into a component explained by edge effect and a second component introduced by other factors such as micro site conditions and disturbance. The second component is treated as an unexplained residual variance. In order to provide a realistic simulation of a stand output at a finer, tree level, this second stand variance needs nonetheless to be quantified. The variance attributable to factors other than the edge effect is mimicked by generating a random number by means of a parameterised stochastic process based on the variance of the inner stand region, which is beyond the reach of the edge effect. In this way, a realistic spatial pattern of a plantation forest stand, taking into account the edge effect and combining it with the natural stand variance is achieved. This study, within the field of plantation forest management, aspires to land use optimization both in terms of productive capacity estimation and for the provision of information for effective land use management planning. It makes use of open source software resources namely the R framework and QGIS and explores aerial stereophotogrammetry as an option for data collection. / AFRIKAANSE OPSOMMING: Een van die hoofdoelwitte in plantasie bosbou praktyk is hoё vlakke van homogeniteit met betrekking tot die verspreiding en die dimensies van die bome in die plantasie opstand. Simetriese aanplantings, intensiewe bosboupraktyk en genetiese seleksie word gebruik om hierdie homogeniteit te verkry. Natuurlike verskille word egter nog steeds gevind as gevolg van groeiplek mikro toestande en ander versteurings in die opstand. Een van die hoofbronne van hierdie variasie is die randeffekte van buurplantasies en ander gebruike van grond. Hierdie randeffekte veroorsaak dat bome aan die rand van die opstand anders ontwikkel as die bome binne in die opstand. Die oorhoofse doelwit met hierdie navorsing is om die randeffekte te simuleer. Hierdie randeffekte is gegrond op die gemiddelde binneopstand boom veranderlikes soos afgelei uit die opmeting en uit ruimtelike inligting oor die huidige en geskiedkundige toestande in die omgewing. As hierdie natuurlike variasies asook die ruimtelike patrone weer in berekening gebring word, verwag ons om beter beplanningsinligting te bekom. ’n Belangrike doelwit tydens hierdie navorsing is dus om die effek van die rand-­‐interaksie te skei van die effek van ander faktore wat bydra tot variasies binne-­‐in die opstand en om die resultaat in terme van plantasie produksie te kwantifiseer. ’n Metodiek word voorgestel vir die kwantifisering van die interaksie op die rande tussen die opstand en die buuropstande tydens die leeftyd van die opstand. Die oorplasing van die rand interaksie waarde van die rand af na al die bome in die plantasie word dan gedoen deur om geweegde inverse afstand interpolasie vanaf die rand tot by die ligging van die boom, toe te pas. As die rand interaksie waarde vir elke punt bereken is, kan die omvang van die randeffek gekwantifiseer word. Die ruimtelike omvang van die rand effek is, met die gebruik van breekpunt regressie, empiries afgelei van ’n bestaande ten volle karteerde plantasie. Die verwagte variasie as gevolg van die randeffek word dan met die gebruik van ’n stel modelle gekwantifiseer, wat dan die effek van die rand interaksie op boomhoogte, deursnit en volume kan weergee. Die randeffek word as ’n dinamiese interaksie beskou waarvan die tydsaspek in ag geneem moet word, want die huidige ruimtelike struktuur van die plantasie word beïnvloed deur die huidige omgewing asook deur die historiese ontwikkeling van die omgewing met betrekking tot die opstand onder bespreking. Elke opstand ondergaan ’n randeffek wat uniek is aan daardie plantasie op die gegewe tydstip. Die doelwit is om ’n wyse te vind waarvolgens groei-­‐en-­‐opbrengs plantasie modellering deur die insluiting van randeffek op ’n praktiese wyse, aangevul kan word. Om hierdie rede is die aanbevole metodiek ruimtelik-­‐tydelik en gerig daarop om ’n wyse te vind waarvolgens groei-­‐en-­‐opbrengs modellering deur die insluiting van die randeffek, op ’n praktiese wyse aangevul kan word. Om randeffek eksplisiet te kwantifiseer, moes die natuurlike afwyking gedeel word in die komponent wat die gevolg is van die randeffek, en ’n tweede komponent wat die gevolg is van ander faktore soos mikroligging toestande en versteurings. Die tweede komponent word behandel as ’n onverklaarde oorblywende afwyking. Hierdie tweede plantasie afwyking moet nogtans kwantifiseer word om sodoende ’n realistiese simulasie van plantasie opbrengs op ’n fyner boom vlak te verkry. Die afwyking wat toegeskryf kan word aan faktore buiten die randeffek, word nageboots deur om ’n lukrake nommer (wat gebaseer word op die afwyking van die binne-­‐plantasie gebied wat buite die strekwydte van die randeffek is) deur middel van ‘n geparameteriseerde stogastiese proses te genereer. Sodoende word ’n realistiese ruimtelike patroon van ’n plantasie opstand verkry, wat die randeffek in ag neem en dit kombineer met die natuurlike plantasie afwyking.

Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Red Lapacho is timber species with largest market value, considered along with Mahogany, as 'green gold' in areas of natural forest logging. Therefore, the objective of this study was to analyze the different factors that influence the growth of this species, taking into consideration the spatial and temporal dependence inherent to the data. A census of Red Lapacho individuals was carried out in a natural fragment of Subtropical Deciduous Forest with approximately 13 hectares of area. Quantitative morphological and diameter increment data were obtained for each tree of this species. Competitors defined by Bitterlich plots were measured and identified, and a regular grid with infill points of soil sampling were also analyzed. Spatial patterns of distribution of Red Lapacho and its dimensions had completely spatial randomness patterns. Sampled species richness from competitors was of 60 species and the competition generated by them had a random spatial pattern as well. A model for the height – diameter relationship using Generalized Additive Mixed Models (GAMM) produced better results when the latent spatial pattern was included in the model. The spatial patterns of nutrient availability were influenced by relief of the area and distance from the edge of the forest and grassland environments. Anionic nutrients were strongly influenced by the spatial dynamics of the two vegetation types while cations were influenced mainly by pedogenesis. The spatio-temporal Bayesian diameter increment model developed for the Red Lapacho trees showed that there was considerable inter – annual variation in tree growth. The spatial variation in tree growth was closely related to the pedogenesis of the area under study, more specifically, lower increments were observed in areas where the soil had signals of water influence in tits formation. Using site proxies based on geocentric, phytocentric and dendrocentric approaches was able to take into consideration the spatial variation in the growth of Red Lapacho trees and, all approaches may be utilized in the development of growth models. / O Ipê – Roxo é uma das espécies de madeira com maior valor de mercado, sendo considerado, juntamente com o Mogno, o 'ouro verde' em áreas de exploração de florestas naturais. Assim sendo, o objetivo deste estudo foi analisar os diferentes fatores que influem no crescimento desta espécie, levando em consideração a dependência espacial e temporal inerente aos dados. Foi realizado um censo dos indivíduos de Ipê – Roxo em um fragmento natural de Floresta Estacional Decidual com aproximadamente 13 hectares. Foram levantados dados morfométricos e de incremento em diâmetro de cada uma das árvores desta espécie. Os competidores definidos por parcelas de Bitterlich foram medidos e identificados e, uma grade regular com pontos de preenchimento para amostras de solo foram avaliados. Os padrões espaciais de distribuição das árvores de Ipê – Roxo e suas dimensões se adequaram à completa aleatoriedade espacial. A riqueza de espécies amostradas como competidores foi de 60 espécies e a competição por estas gerada também teve padrão espacial aleatório. A modelagem da relação hipsométrica das árvores utilizando Generalized Additive Mixed Models (GAMM) obteve melhor ajuste quando o padrão espacial latente foi incluso no modelo. Os padrões espaciais de disponibilidade dos nutrientes foram afetados pelo relevo da área e pela distância da borda dos ambientes florestal e campestre. Nutrientes aniônicos foram fortemente influenciados pela dinâmica espacial entre os dois tipos vegetais enquanto cátions foram influenciados principalmente pelo processo pedogênico. O modelo espaço – temporal Bayesiano de incremento em diâmetro desenvolvido para as árvores de Ipê – Roxo mostrou que existe considerável variação inter - anual do crescimento. A variação espacial do crescimento também se mostrou relacionada com o processo pedogênico da área sob estudo, sendo que menores incrementos foram observados em áreas onde o solo apresentou sinais de hidromorfismo. A utilização de estimadores de sítio baseados em índices geocêntricos, fitocêntricos e dendrocêntricos foi capaz de levar em consideração a variação espacial do crescimento de árvores de Ipê – Roxo e, todos podem ser utilizados para a construção de modelos de crescimento.

I Sverige ställs allt högre krav på nya byggnader genom bestämmelser och lagar som påverkar energianvändningen. Byggnader kan värmas upp med hjälp av olika typer av distributionssystem såsom radiatorer och golvvärme. Värmebehovet hos byggnaden baseras på hur mycket värmeenergi som behövs för att uppnå termisk komfort. För att begränsa energianvändningen används isolering i syfte att minimera värmeförlusterna genom byggnadens klimatskärm. Denna undersökning syftar till att undersöka förluster som sker genom kantbalken vid användning av vattenburet golvvärmesystem och hur dessa förluster påverkas då grundkonstruktionen tilläggsisoleras på olika sätt. Kantbalken är den förstärkta del som finns under markplattan/platta på mark, tar upp krafter från bärande väggar och finns efter sidorna på byggnaden. Golvvärme är en uppvärmningsteknik där slingor placeras i grundkonstruktionen och förser byggnader med dess värmebehov. Golvvärmesystem installeras på olika sätt beroende på byggnaders förutsättningar och är ett energieffektivt uppvärmningssätt i kombination med värmepump. Undersökningen påbörjades genom att skapa en förenklad modell som behandlar en 2-dimensionell kantbalksutformning i COMSOL Multiphysics, som är ett program för modellering där statiska och dynamiska simuleringar genomförs i modeller med hjälp av finita-elementmetoden. Fyra modeller skapades med två olika CC-mått (centrumavstånd) och två olika golvmaterial. Därefter skapades tre fall med förbättrande åtgärder för att öka kantbalkens isolerförmåga. Dynamiska simuleringar genomfördes och hade tidsintervallet 365 dagar med varierande utetemperatur. När utetemperaturen varierade var effektbehovet hos golvvärmen olika vilket ledde till att golvvärmetemperaturen justerades efter utetemperaturen för att upprätthålla samma temperatur på golvytan. Resultaten visar att kantbalken står för cirka 50 % av markkonstruktionsförlusterna med installerat L-element. Vid komplettering av konstruktionen med två fall av tillläggsisolering framkom inga större förändringar i resultaten. Genom att byta ut L-elementet till ett U-element minskar dock värmeförlusterna genom kantbalken till ca 30 %. Markkonstruktionsförluster är de förluster som överförs från byggnaden till närliggande mark. / Through laws and regulations in Sweden, increasing demands regarding energy use are affecting new buildings. A building achieving thermal comfort is attaining its thermal needs and can be done so through several types of distribution systems such as radiators and underfloor heating. Insulation is used to limit the amount of energy lost through the building’s envelope whilst keeping up with the thermal needs. This study is meant to examine the thermal leakage around the edge beam installa-tion when using a waterborne underfloor heating system and different sets of insulation are installed in the ground-related construction. The edge beam is the reinforced part located around the perimeter of the building absorbing forces from supporting walls. The study started with creating and using a simplified model in COMSOL Multiphysics to look at a two-dimensional edge beam formation. COMSOL Multiphysics is a software used for modeling different static and dynamic simulations via the finite element method. Four models were created using two different CC-dimensions (center to center distance) and two different floor materials. After this, three cases were created with improved circumstances regarding the ability to isolate heat around the edge beam. Dynamic simulations were made and calculated a year’s worth of varying outdoor temperatures. When the outdoor temperature changes, the requirements of the underfloor heating output also change which leads to its temperature adapting due to the outdoor temperature. The results indicate the edge beam related heat losses make up of about 50 % of the ground-related construction losses in the model. When completing the design with two instances of additional insulation, no major changes were found in the results. However, replacing the L-shaped insulation around the edge beam with a U-shaped insulation reduces heat losses through the edge beam to about 30 %. Ground-related construction losses are the losses transferred from the building to adjacent ground.

L’interprétation du contenu de l’image est un objectif très important dans le traitement de l’image et la vision par ordinateur. Par conséquent, plusieurs chercheurs y sont intéressés. Une image contient des informations multiples qui peuvent être étudiés, telles que la couleur, les formes, les arêtes, les angles, la taille et l’orientation. En outre, les contours contiennent les structures les plus importantes de l’image. Afin d’extraire les caractéristiques du contour d’un objet, nous devons détecter les bords de cet objet. La détection de bords est un point clé dans plusieurs applications, telles que :la restauration, l’amélioration de l’image, la stéganographie, le filigrane, la récupération, la reconnaissance et la compression de l’image, etc. Toutefois, l’évaluation de la performance de la méthode de détection de bords reste un grand défi. Les images numériques sont parfois modifiées par une procédure légale ou illégale afin d’envoyer des données secrètes ou spéciales. Afin d’être moins visibles, la plupart des méthodes stéganographiques modifient les valeurs de pixels dans les bords/textures de parties de l’image. Par conséquent, il est important de détecter la présence de données cachées dans les images numériques. Cette thèse est divisée principalement en deux parties.La première partie discute l’évaluation des méthodes de détection des bords du filtrage, des contours et des angles. En effet, cinq contributions sont présentées dans cette partie : d’abord, nous avons proposé un nouveau plan de surveillance normalisée de mesure de la qualité. En second lieu, nous avons proposé une nouvelle technique pour évaluer les méthodes de détection des bords de filtrage impliquant le score minimal des mesures considérées. En plus, nous avons construit une nouvelle vérité terrain de la carte de bords étiquetée d’une manière semi-automatique pour des images réelles.En troisième lieu, nous avons proposé une nouvelle mesure prenant en compte les distances de faux points positifs pour évaluer un détecteur de bords d’une manière objective. Enfin, nous avons proposé une nouvelle approche de détection de bords qui combine la dérivée directionnelle et l’homogénéité des grains. Notre approche proposée est plus stable et robuste au bruit que dix autres méthodes célèbres de détection. La seconde partie discute la stéganalyse de l’image en couleurs, basée sur l’apprentissage automatique (machine learning). En effet, trois contributions sont présentées dans cette partie : d’abord, nous avons proposé une nouvelle méthode de stéganalyse de l’image en couleurs, basée sur l’extraction de caractéristiques de couleurs à partir de corrélations entre les gradients de canaux rouge, vert et bleu. En fait, ces caractéristiques donnent le cosinus des angles entre les gradients. En second lieu, nous avons proposé une nouvelle méthode de stéganalyse de l’image en couleurs, basée sur des mesures géométriques obtenues par le sinus et le cosinus des angles de gradients entre tous les canaux de couleurs. Enfin, nous avons proposé une nouvelle méthode de stéganalyse de l’image en couleurs, basée sur une banque de filtres gaussiens orientables. Toutes les trois méthodes proposées présentent des résultats intéressants et prometteur en devançant l’état de l’art de la stéganalyse en couleurs. / Interpretation of image contents is very important objective in image processing and computer vision. Wherefore, it has received much attention of researchers. An image contains a lot of information which can be studied such as color, shapes, edges, corners, size, and orientation. Moreover, contours include the most important structures in the image. In order to extract features contour of an object, we must detect the edges of that object. Edge detection results, remains a key point and very important step in wide range of applications such as: image restoration, enhancement, steganography, watermarking, image retrieval, recognition, compression, and etc. An efficient boundary detection method should create a contour image containing edges at their correct locations with a minimum of misclassified pixels. However, the performance evaluationof the edge detection results is still a challenging problem. The digital images are sometimes modify by a legal or illegal data in order to send special or secret data. These changes modify slight coefficient values of the image. In order to be less visible, most of the steganography methods modify the pixel values in the edge/texture image areas. Therefore, it is important to detect the presence of hidden data in digital images. This thesis is divided mainly into two main parts. The first part, deals with filtering edge detection, contours evaluation and corners detection methods. More deeply, there are five contributions are presented in this part: first, proposed a new normalized supervised edge map quality measure. The strategy to normalize the evaluation enables to consider a score close to 0 as a good edge map, whereas a score 1 translates a poor segmentation. Second, proposed a new technique to evaluate filtering edge detection methods involving the minimum score of the considerate measures. Moreover, build a new ground truth edge map labelled in semi-automatic way in real images. Third, proposed a new measure takes into account the distances of false positive points to evaluate an edge detector in an objective way. Finally, proposed a new approach for corner detection based on the combination of directional derivative and homogeneity kernels. The proposed approach remains more stable and robust to noise than ten famous corner detection methods. The second part, deals with color image steganalysis, based on a machine learning classification. More deeply, there are three contributionsare presented in this part: first, proposed a new color image steganalysis method based on extract color features from correlations between the gradients of red, green and blue channels. Since these features give the cosine of angles between gradients. Second, proposed a new color steganalysis method based on geometric measures obtained by the sine and cosine of gradient angles between all the color channels. Finally, proposed a new approach for color image steganalysisbased on steerable Gaussian filters Bank.All the three proposed methods in this part, provide interesting and promising results by outperforming the state-of-art color image steganalysis.

This dissertation is concerned with Sylvia Plath's late works. Engaging with critical discussion of what constitutes the corpus of Ariel, I show that an appreciation of the editorial history reveals the beginning of a third book (the last poems), and opens up those difficult texts to fresh enquiry. Recent work in Plath studies has focused on visual art. Kathleen Connors and Sally Bayley's Eye Rhymes examines Plath’s own artwork in ‘an attempt to answer the question, How did Plath arrive at Ariel? (1) I contribute to that discussion, but also ask the questions, How did Plath leave Ariel behind and arrive at the even more remarkable last poems, and how did visual art enable those journeys? I argue that Ariel’s characteristically lucid style is informed by the dismantling of depth perspective in Post-Impressionist painting, and by the colour theory and pedagogy of the Bauhaus teachers. My work is underpinned by an appreciation of Plath’s unique cultural moment in mid-century East Coast America. I show how Plath’s knowledge of the theories, practice and iconic images of visual art, from the old masters to the Post-Impressionists, offered new possibilities for stylistic development. Working with archival materials including annotated works from Plath’s personal library and drafts of her poems, as well as published material, I examine the synthesis of visual and literary influences. Demonstrating specific textual relations between Plath and the work of Emily Dickinson, T. S. Eliot and W. B. Yeats, as well as other poets, I show that Plath’s visual poetics combine influences from the modern poets with her New Critical training and with painting and sculpture. I offer new readings of rarely discussed poems, such as ‘Totem’, ‘The Munich Mannequins’ and ‘Child’, as well as fresh insights into the well known works, ‘Tulips’, ‘The Moon and the Yew Tree’, ‘Fever 103º’, and ‘Edge’.