Tesi sul tema "Reflection of objects"

I have studied two magnetic properties of superconductors using different neutron scattering techniques. Due to their magnetic moment and lack of electrical charge, neutrons can provide an extremely sensitive probe into magnetism on a small scale. Unusual magnetic structures have previously been observed in the non-superconducting PrBa₂Cu₃O₆+_δ, in particular showing a coupling between the rare-earth and the Cu-O₂ planes. For comparison, I have used elastic neutron scattering to measure the temperature dependent magnetic structure of the high-T_c superconductor NdBa₂Cu₃O₇, and its nonsuperconducting reduced form NdBa₂Cu₃O₆. The magnetic structures of both the Nd and Cu sub-lattices are presented. Measurements are shown for single crystals of both the oxygenated and reduced form, and also for a non-stoichiometric single crystal with Nd substituted on the Ba sites. I present a quantitative analysis of the magnetic moments, with account taken of the instrumental resolution including sample mosaicity and intrinsic peak shapes. No evidence was found for any coupling of the type seen in PrBa₂Cu₃O₆+_δ. Many of the underlying properties of superconductors are evidenced in the way magnetic fields are excluded in the different states. I have used polarized neutron reflectometry to measure the magnetic field profile in thin film superconductors. I present measurements for pure niobium and preliminary measurements for YBa₂Cu₃O₇. The samples studied are much thicker than those previously measured, to provide a closer match to the bulk superconductor properties and allow meaningful measurements of the higher field states. For niobium, the applied field dependence is measured for fields covering the Meissner and mixed states, and models are compared for these states and the surface superconductivity state.

The interfacial behaviour of several surfactant mixtures containing zwitterionic surfactants has been studied employing surface tension measurements and neutron reflection experiments. The mixing of surfactants at air-liquid interface could not be well understood using the pesudophase approximation and the regular solution model. By introducing the expansion of excess free energy to analysis the surface tension and neutron reflection data simultaneously, it is found that the mixing deviates strongly from ideal and the excess free energy is asymmetric. It is observed that the presence of ionic surfactant at solid-liquid interface enhanced the adsorption of zwitterionic surfactants. The configuration of the surfactant molecule in the inner layer adjacent to the surface is invoked to explain the underlying mechanism. Maxima in the adsorption just above the CMC occurred at all three compositions studied for the mixed system SDS with dodecyl dimethylammonium propanesulfonate (DSB). The neutron reflection experiments suggest that the phenomenon may result in part from the mixture and in part from ion segregation in the micelles. Structural studies on a series of dodecyl dimethylammonium acetate with different inter-charge spacer revealed that the configuration of the surfactants changes dramatically as the headgroup gets larger. Combined with the higher pKa value, it is highly possible that the carboxybetaine with longer spacer is adsorbed in its undissociated form, and the headgroup is oriented towards the air. This configuration might explain why the saturated monolayer structure is favoured over the micellization.

Czochralski (Cz) silicon wafers are used almost exclusively for the fabrication of VLSI devices. Such silicon contains excess oxygen which precipitates as oxide particles either when the initial ingot is grown or subsequently during the wafer device fabrication. Such oxide particles can produce reduced device performance or failure if they occur within the active device regions. However, they can be used to improve the device performance by a process known as internal oxide gettering. The wafers are given a series of preanneal treatments to produce controlled precipitation in which a surface zone of the wafer to a depth of typically in the range of 10 to 50 μm is denuded of oxide particles, while the remainder of the wafer contains large numbers of well formed particles. The devices are fabricated in the surface denuded zone and harmful contaminating metal impurities are attracted during the heat treatment stages away from the device regions to precipitate at the underlying oxide particles or their associated dislocations. In this way device yields can be significantly increased. Because of the importance of these oxide particles and the oxygen precipitation process for VLSI fabrication, considerable efforts have been made to develop methods to assess the numbers and distributions of such particles within the wafers. The number density range of most interest is 10⁷ to 10¹⁰ cm^-3, and the particle size range is typically 30 to 300 nm. The method that has mostly been used is surface etching followed by optical microscopy to obtain etch pit densities. Transmission electron microscopy is a research method used for obtaining detailed information concerning a small number of individual particles. However, because these methods are destructive, much attention has been given during the last few years to the development of infra-red microscopy methods to directly image the particles within the silicon wafers. Although the particles are smaller than the resolution of these methods, individual particles can nevertheless be imaged. This is because the particles are mostly further apart than the resolution limit, and the sensitivity can be sufficient high that adequate contrast occurs. The contrast arises from scattering or absorption of the light by the particle. Infra-red imaging methods developed include infra-red microscopy (IRM), laser scattering tomography (LST), optical precipitate profiler (OPP) and scanning infra-red microscopy (SIRM), all described more fully in Chapter 2. The SIRM has been developed and used to investigate a variety of semiconductor specimens in the Materials Department, Oxford University, during the last ten years. The SIRM has a good performance and flexibility making it especially suitable as a research instrument. Although all of these infra-red imaging methods have been successful to different degrees in assessing oxide particles in Cz silicon wafers, their performance has at least initially been assessed by comparing the number densities and distributions thus obtained with the corresponding results produced by etch pit studies. Furthermore, no serious attempt has yet been made to develop a rigorous theory of the imaging process and to compare the predictions with the experimental images. One of the main objectives of the present work is to do this or at least to make a significant start to such a project based on the SIRM. The outline of an ideal project which aims at a full understanding of the imaging process and the contrast mechanisms is as follows. The performance of the present Oxford SIRM should be improved and the number of imaging modes increased. The improved performance, i.e. better lateral and depth resolutions and higher sensitivity, would enable smaller particles and higher number densities to be imaged, and hence better quantitative data obtained. The larger number of imaging modes would enable the optimum method to be used to image different types of particle. A rigorous theory should be developed that can describe the imaging process and the contrast mechanisms. First, the illumination system should be studied, and in particular the structure of the focussed probe within the specimen and how the structure changes on focussing deeper into the specimen. Second, the interaction of the light with the specimen should be investigated and especially how light is scattered by individual oxide particles in silicon for the case of the particle size being smaller than the light wavelength. Third, the detection system should be considered. For example, for the reflection confocal SIRM, how the light back scattered by the particles is collected by the probe forming lens and imaged at a pin-hole aperture placed in the front of the detector. Well designed experiments are required to determine the imaging properties of the different modes and comparisons should be made between the experimental and theoretical data. The successful conclusion of such a project would enable SIRM images of the particles to be more fully interpreted and hence more detailed information obtained concerning the particles. Furthermore, the images expected from different types of particle could be more closely predicted, e.g. whether they are detectable or not, and hence materials projects could be better planned at the outset. In this thesis we describe the methods that are presently being used to assess oxide particles in bulk silicon (Chapter 2). We review the literature on scanning optical microscopy covering both visible and infra-red light, present some considerations regarding the design of a high performance and versatile SIRM, and describe the various microscope modes that have been or could be used to image particles in semiconductors with infra-red light (Chapter 3). We give a detailed rigorous theoretical analysis of the energy distributions in the probe for the case when the light is focussed by a high numerical aperture lens from air into silicon (Chapters 4, 5). Numerically computed distributions are obtained to illustrate how the probe changes under different conditions, e.g. different focussing depths (Chapter 6). The relationship between the penetration depth of the probe and the spherical aberration coefficient arising from the silicon specimen is determined (Chapter 7). The classical theory of light scattering is applied to individual spherical silicon dioxide particles embedded in silicon. Numerical results are presented and a contrast mechanism is proposed to describe how the scattered intensity depends on particle size (Chapter 8). A formal solution relevant to the reflection confocal SIRM is given to treat the backward propagation of light using a model which takes into account the polarisation state of the incident light, the spherical aberration introduced by the silicon wafer, the polarisation state of the scattered light and the size of the pin-hole (Chapter 9). Experimental results are obtained for most of the imaging modes described in Chapter 3, specimens being selected so that the wide range of the imaging capabilities of the SIRM is shown, and experimental contrast values are compared with theoretical values (Chapter 10). Finally, overall conclusions are drawn and suggestions are made for completing the work started here (Chapter 11).

Abstract Interacting many-body problems are central to most fields of physics. In condensed matter physics, the systems of interest consists of a number of bodies on the order of Avogadro's constant, ~10²³. The precise modeling of such systems is usually impossible. Under certain circumstances however, even these problems can become tractable. One such circumstance is that of a Fermi liquid. At sufficiently low temperatures, in describing the dynamics of a system of interacting fermions, it is possible to forgo description of the fermions themselves, and instead concentrate on the collective excitations of the entire fermion system. These collective excitations are called quasiparticles. In this thesis we study two phenomena related to the motion of objects in a Fermi liquid. First, we study the transmission of transverse oscillations through a thin film of normal Fermi liquid. The dynamics of normal Fermi liquid are described by Landau's Fermi liquid theory. Landau's theory predicts the existence of new modes of sound under conditions where sound ordinarily would not propagate. Using the equations of motion for the Fermi liquid quasiparticles, we calculate the linear response of a Fermi liquid film to the transverse oscillations of a planar substrate under a wide range of conditions. We present the linear response in terms of the film's acoustic impedance and study the effects of quasiparticle collisions and of the Fermi liquid interactions. The second phenomenon we study is the supercritical motion of a wire in a superfluid Fermi liquid. The prevailing assumption is that if the velocity of an object moving in a superfluid Fermi liquid surpasses a characteristic critical velocity, the object experiences a sudden onset of viscous forces. This viscosity is caused by the escape of quasiparticles, produced by pair breaking on the surface of the object, into the surrounding superfluid. We study Andreev reflection of the quasiparticles by the surrounding superfluid flow field, and modifications to the flow caused by pair breaking, as possible mechanisms for low-dissipation motion above the critical velocity
Original publications The original publications are not included in the electronic version of the dissertation. Kuorelahti, J. A., Tuorila, J. A., & Thuneberg, E. V. (2016). Fermi liquid theory applied to a film on an oscillating substrate. Physical Review B, 94(18). https://doi.org/10.1103/physrevb.94.184103 Kuorelahti, J. A., & Thuneberg, E. V. (2018). Two-parameter boundary condition applied to transverse acoustic impedance of a Fermi liquid. Journal of Physics: Conference Series, 969, 12010. https://doi.org/10.1088/1742-6596/969/1/012010 http://jultika.oulu.fi/Record/nbnfi-fe2018060425173 Kuorelahti, J. A., Laine, S. M., & Thuneberg, E. V. (2018). Models for supercritical motion in a superfluid Fermi liquid. Physical Review B, 98(14). https://doi.org/10.1103/physrevb.98.144512 http://jultika.oulu.fi/Record/nbnfi-fe2018112148794

Um dos problemas técnicos que ocorrem nos revestimentos cerâmicos é a possibilidade de duas peças serem da mesma cor sob a luz do dia, mas de cores diferentes sob outra iluminação. Tal fenômeno é chamado metamerismo. O presente trabalho teve como objetivo realizar um estudo sobre a influência de variáveis do processo de fabricação de revestimentos cerâmicos na ocorrência do fenômeno de metamerismo, tendo como objeto de estudo uma peça monoporosa de esmalte branco-brilhante, e um porcelanato mate. Para tanto, avaliou-se o efeito da variação de iluminante, correlacionado com as seguintes características dos revestimentos cerâmicos investigados: i) tipologia de esmalte; ii) base, engobe esmaltes; iii) variação de camada; iv) utilização de quartzo, caulim e zirconita; v) variação de corantes. Os resultados mostraram que esmaltes, como o branco-brilhante, se destacam no aparecimento da característica metamérica, tanto mais quanto mais espessa a camada. Já, quando se aumenta a camada do mate, este fenômeno ameniza. A zirconita, por ser um opacificante, ameniza a reflexão da luz, gerando uma diminuição do metamerismo. O quartzo promove o metamerismo, já que influencia no aparecimento do brilho. Quanto aos corantes, pigmentos que amenizam o reflexo da luz, como o preto e cinza, possuem um valor metamérico baixo, já pigmentos que tendem ao reflexo maior da luz, promovem o metamerismo. Com base nisso, o suporte do porcelanato esmaltado que se apresenta em uma base cinza, possui um valor metamérico menor que a base da monoporosa, que possui uma cor bege. Ficou evidenciada a influência das curvas espectrais e do reflexo no aparecimento do metamerismo, podendo ser um ponto crucial para que empresas trabalhem em cima deste problema, a fim de ser um diferencial para seus clientes no mercado competitivo como o de hoje.
One of several problems that occur in ceramic tiles, is the possibility that two objects are the same color in the light of day, but of different colors in a different light. This phenomenon, in which two colors are similar under a light source but different under another, is called metamerism. Seeking a study on this phenomenon was analyzed the influence of some variables on the metamerism in a white enamel-bright monoporosity, and a matte porcelain. Some of the variables selected for the study of the influence of the media, and enamel on engobe metamerism, the addition of opacifier material, in suspension and bright enamels in different percentages, the analysis with the addition of pure colors and mixtures of the same in glazes; variations in the enamel layer, among other factors. Before, it was noticed that the enamel provide a high spectral curve, ie, materials that reflect the highly light, tend to influence the onset of this phenomenon. Thus, materials that influence the formation of brightness as quartz help this phenomenon to emerge since opacifying materials that have the feature to break it brightness, ie, which have lower spectral curves, decreases the appearance of this phenomenon. In the matter of color is the same as explained above, ie, pigments that mitigate the reflection of light as the black and gray, have a low value metameric because colors tend to reflect more light, raise this value. On this basis, the support of porcelain enamel that comes in on a gray metameric has a value less than the base of monoporosity, which has a beige color. Having knowledge of these factors, it is clear the influence of spectral curves and reflex formed by these variables in the emergence of this phenomenon and may be a crucial point for companies to work upon this problem, in order to be a differentiator for its customers in competitive market which is today.

A wide variety of tectonic settings are juxtaposed at the southern margins of the Iberian Peninsula. The regional geology comprises an Atlantic passive margin in western Iberia, the convergent eastern part of the Azores-Gibraltar plate boundary zone between Africa and Eurasia, and an orogenic arc (the Betic-Rif mountains) surrounding an extensional basin (the Alboran Sea). The complex tectonic history of the southern Iberian margins is recorded in its sediments and structure, and these were investigated in this study using multichannel seismic reflection techniques in conjunction with other marine geophysical data. Multichannel seismic reflection and well data from the Gulf of Cadiz have shown that the earliest sediments are Triassic evaporites, followed by Jurassic carbonates, which form rotated fault blocks in the Gulf of Cadiz. Backstripping and thermal modelling has indicated that a rifting event took place in the Late Jurassic, which stretched the crust by ~20-50%. Gravity modelling, and mapping of stretching factors, has suggested that two zones of thinning underlie the Gulf of Cadiz, which are related to the original rifting event. Backstripped subsidence curves indicate passive margin thermal subsidence until the Miocene, when westward-directed thrusting and loading from the Betic-Rif mountain belt is reflected in a typical foreland basin tectonic subsidence signature of accelerated subsidence with time. A giant, chaotic body of allochthonous sediment was emplaced into the central Gulf of Cadiz as westward migration of the Gibraltar Arc led to oversteepening of the margin west of the Gibraltar Straits, while the Alboran Sea was simultaneously undergoing active extension. These allochthonous deposits are composed mainly of Triassic evaporites and Palaeogene shales. In the Gulf of Cadiz and Seine Abyssal Plains this body has the appearance of an accretionary wedge, but a 300 km long northern lobe of the body extends into the Horseshoe Abyssal Plain. This lobe is interpreted as being a cumulative mass wasting feature, formed by the gravity-driven downslope transport of large allochthonous masses as debris flows and slides and slumps, encouraged by a regional gradient and a pre-existing trough in the Horseshoe Abyssal Plain. The total volume of sediments involved was of the order of 72 000 km 3 , and the time of emplacement has been estimated as being Tortonian on the basis of seismic correlation with core data at DSDP site 135. This chaotic unit has formed a series of longitudinal diapiric ridges in the northern Gulf of Cadiz, which have been interpreted to act as a transport system for gas generated in the lower slope area to migrate to the upper slope where gas-related features are seen. Gas hydrates are present beneath the lower continental slope, as inferred from a bottom-simulating reflection on seismic reflection profiles.

The discovery of the existence of the cell membrane has led to a search for its organization on a molecular scale. The advent of artificial lipid bilayers and the development of electron microscopy in the 1930's provided direct visual evidence for the existence of the cell membrane and drove forward models of membrane structure based its known composition of proteins, lipids and carbohydrates. The fluid mosaic model of membrane structure, based on thermo- dynamics and newly developed protein structural studies of the time, placed integral globular membrane proteins within a fluid phospholipid bilayer. This model allowed for the association of proteins into groups and the possible mobility of proteins within the lipid bilayer. At the the same time fluorescence microscopy demonstrated movement of proteins in the plane of the lipid bilayer. Since then experimental techniques have been developed that show protein complexes of varying sizes do exist and so this gives us the opportunity to ask how receptor proteins fit into the molecular organization of the cell membrane. This thesis presents an investigation into how the epidermal growth factor receptor (EGFR) organizes in the cell membrane of colorectal carcinoma cells. First a new cell line for studying the receptor by stably expressing the epidermal growth factor receptor conjugated to enhanced green fluorescent protein (EGFR-eGFP) in SW620 cells was developed. This is an interest- ing cell line because it originates from a colonic adenocarcinoma that during the process of metastasis has lost the ability to express the EGFR. It therefore provided an environment for the expression of the fluorescent form of the receptor more in keeping with its natural environment. The technique of total internal reflection fluorescence (TIRF) microscopy was used to visualize the fluorescently tagged receptor in the cell membrane. This technique uses the principles of total internal reflection to excite fluorescence in molecules located only 100 nm into the cell. Because sources of fluorescence from outside the illuminated area are minimized individual fluorescent molecules can be imaged. The spots in the images, produced by the fluorophores, were detected using a single molecule detection and tracking algorithm. The intensities of these detected spots were analysed and compared with that from a single molecule of enhanced green fluorescent protein (eGFP). This gave an estimate of the number of receptors contained within each receptor complex. Before ligand binding most of the receptors were found to be located in complexes containing up to eight molecules and most frequently they were found in complexes of two molecules. Larger complexes of receptors were found to have formed after activation of the receptor by its ligand.

The thesis argues that we can maintain that the so-called History of David’s Rise (HDR) existed independently before the deuteronomistic work, by identifying its beginning in I Samuel 16. 14 and ending in II Samuel 5. 3. Additionally, the thesis proposes that the source was first composed during Hezekiah’s reign with a view to persuading the northerners to embrace Hezekiah’s one Israel policy, and then went through two major redactions – one in the late exilic period and the other in the post-exilic period. These later redactions were prompted not only by the political situations of the time, but also by the literary milieu. In other words, a growing interest in narratives and the emergence of the ‘Jewish novelistic impulse’ in the Neo-Babylonian and Persian period triggered the creation of more extensive narratives about Saul and David. These historical-critical arguments are preceded in the thesis by a methodological argument that a traditio-historical issue is inevitably related to a literary understanding of the larger whole. The background for this two-foci research is the wild disagreement on the issue, and the confusion around the methodology that has been aggravated by an unnecessary tension between different approaches. The thesis therefore discusses the methodological issues as carefully as possible, so that it might be transparent what actually happens when one does biblical criticism. This gives the thesis the features of a case study, but the thesis also hopes to present a satisfactory and attractive view on a particular traditio-historical issue in its own right. The study hopes to be an experiment of self-reflective biblical criticism that is serious but open. Since the thesis has two different but essentially related theses, the conclusion is established in two stages – methodological and historical. Chapter 1 shows that a literary understanding of the whole is foundational to traditio-historical discussions, and Chapter 2 demonstrates that literary understanding is always open to revision, and so are historical answers, as the latter are inevitably related to the former. Chapter 3 asks what is the most appropriate understanding of the whole HDR at this point, and the answer provides the last two chapters with the foundation by which various evidences can be measured. Chapter 4 revisits the initial question, and provides a provisional answer. And Chapter 5, after discussing the relationship between the materials in the books of Samuel, confirms the conclusion reached in the previous chapter, and elaborates further implications.

The adsorption and the aggregation behaviour of poly(ethylene oxide-b-propylene oxide- b-ethylene oxide) copolymers (EPE) and their mixtures with surfactants of different ionic characters: sodium dodecyl sulphate (SDS), dodecyltrimethylammonium chloride (DTAC) and tetraethylene glycol monooctyl ether (C₈E₄), have been investigated using surface tension and neutron reflection measurements. The first part of the thesis is concerned with the adsorption properties of EPE copolymers at the air-solution interface. The surface tension curves for the copolymers show two breaks similar to those published for Pluronic 3 surfactants (commercially available EPE copolymers). Earlier explanations of this behaviour are inconsistent with the neutron reflection results. The adsorption isotherms obtained by neutron reflection have two steps, one at low concentrations leading to a plateau followed by a substantial rise up to the CMC. The low-concentration breakpoint is attributed to two different effects, the depletion of copolymer molecules in the bulk of the solution and the composition polydispersity. In general, the structure of the adsorbed layer can be described in terms of four layers. The outermost layer is always water free and contains only PO units. The EO residues form tails, which extend into the solution over a distance shorter than the fully extended length. Depending on the conditions, some PO is also found in this tail region. The second part of the thesis is concerned with the effect of mixing EPE copolymers with surfactants of different ionic characters. The formation of mixed micelles and mono layer between EPE 3000-14 and ionic surfactants show a surprisingly strong attractive interaction, which is attributed to a dehydration mechanism. In the mixed micelle formation, in particular, the loss of hydration water molecules found in the micelle core of the copolymer would lead to a substantial gain in entropy. The surface compositions from neutron reflection generally disagree with the predictions of Pseudophase Separation Model. It is believed that changes of hydration upon mixing may be responsible for the deviations as it is not taken into account by the Pseudophase Separation Model. From the neutron reflection studies, DTAC appears to accumulate preferably in the uppermost part of the mixed interfacial layer, while SDS would rather stay in the aqueous phase region. In the C₈E₄/EPE 3000-14 system, the mixed micellization results in strong repulsive interaction, which is attributed to a further hydration of the copolymer micelle core by the incorporation of the solvated C₈E₄ headgroups. However at the air-solution interface, both C₈E₄ and EPE 3000-14 are found to mix ideally. The difference between mixed micelle and mono layer formation observed for such a system is believed to be associated with the structure of the two states. The orientation of the copolymer molecules in the interfacial layer is such that the contact of PO groups with water molecules is significantly reduced. C₈E₄ molecules appeared to adsorb preferentially within the uppermost part of the interfacial layer rich in PO groups.

Cratonic basins cover more than 10% of Earth's continental surface area, yet their origin remains enigmatic. In this thesis a suite of new and legacy geophysical and geological data are integrated to constrain the origin of the Parnaíba basin, a cratonic basin in Northeast Brazil. These data include a 1400 km long, deep (20 s two-way travel time) seismic reflection profile, five +/- 110 km offset wide-angle split-spread receiver gathers, gravity anomaly, and well data. In the centre of the basin, the depth to pre-Paleozoic basement is ~ 3.3 km, a zone of midcrustal reflectivity (MCR) can be traced laterally for ~ 250 km at depths between 17-25 km and Moho depth is ~ 42 +/- 2 km. Gravity and P-wave modelling suggests that the MCR represents the upper surface of a high density (2985 kg m³) and V_p (6.7 - 7.0 km s^-1) lower crustal body, likely of magmatic origin. Backstripping of well data shows a concave up decreasing tectonic subsidence, similar in form to that commonly observed in rift-type basins. It is shown, however, that the seismic and gravity data are inconsistent with an extensional origin. It is shown that an intrusive body in the lower crust that has loaded and flexed the surface of the crust, combined with sediment loading, provides a satisfactory fit to the observed gravity anomaly, sediment thickness and basin shape. A buried load model is also consistent with seismic data, which suggest that the Moho is as deep or deeper beneath the basin centre than its flanks and accounts for at least part of the tectonic subsidence through a viscoelastic stress relaxation that occurs in the lithosphere following load emplacement. Comparative analysis of the Michigan and Congo basins shows gravity data from these basins is also consistent with a lower crustal mass excess, while subsidence analysis shows viscoelastic stress relaxation may also contribute to their early subsidence histories. However, unlike Parnaíba, both of these basins appear to have been subjected to secondary tectonic processes that obscure the primary 'cratonic basin' subsidence signals. Parnaíba basin, therefore, offers an excellent record for the investigation of cratonic basin formation.

The largest earthquakes on Earth take place on the megathrusts of subduction zones, but the slip behavior of megathrusts is variable. This thesis considers why by conducting local, regional and global studies of the interrelationships between the structure and seismogenic behavior of subduction zones. New marine geophysical data collected from the collision zone between the Louisville Ridge seamount chain with the Tonga-Kermadec trench constrain overthrusting and subducting plate structure. Mo'unga seamount is identified beneath the outer-forearc, which calibrates the association of residual bathymetric anomalies and subducting relief, implies an E-W geometry for the subducted ridge and suggests the 200 km wide Louisville seismic gap is modulated by the sediment filled flexural moat. Spectral averaging is then applied along the Tonga-Kermadec margin and along strike variations in overthrusting plate structure are verified by wide-angle seismic transects. The remnant Tonga-Ridge occupies the inner fore-arc and residual free-air gravity anomalies constrain its latitudinal extent (north of 30.5°S), width (110±20 km) and strike (~005° south of 25°S). Plate tectonic reconstructions suggest the Lau Ridge is unmodified by subduction related erosion, <200 km of the Tonga Ridge has been eroded, and neither ridge ever occupied the southern Kermadec arc. Crustal thickness variations are thus inherited, reflecting the Cenozoic tectonic evolution of the Tonga-Kermadec-Hikurangi margin. Spectral averaging is finally applied to all subduction zones on Earth. Part one develops a global catalogue of subducting relief, which is compared with seismological and geodetic inferences of fault-slip behavior. Most seamounts are aseismic, relatively undeformed and observations are not consistent with mechanical models proposing full-decapitation. Aseismic ridges are also associated with megathrust complexity, but are of a larger wavelength and contrasting mode of isostatic compensation. Part two shows almost all intra-margin along-strike transitions in seismogenic behavior are related to pre-existing crustal structure. A paired forearc anomaly is interpreted consisting of a trench-parallel ridge landward of the deep-sea-terrace basin. The ridge crest correlates with the down-dip limit of coseismic slip and strong interplate coupling, the up- dip limit of tremor epicentres, and is interpreted as defining the boundary between the velocity-weakening and seismogenic portion of the subduction interface and the down-dip frictional transition zone. Paired anomalies may be attributed to unrecovered interseismic elastic strain, the preferential subduction erosion of the outer-forearc and/or underplating beneath the inner forearc.

As técnicas de programação e os mecanismos de linguagens de programação destinados ao desenvolvimento de aplicações de alta confiabilidade são agrupadas sob a denominação de tolerância a falhas em software. A área de tolerância a falhas abrange uma serie de técnicas com funcionalidades e aplicabilidade bem definidas, permitindo que seja considerada um domínio próprio - o domínio de tolerância a falhas. O conteúdo de informação desse domínio não é auto-suficiente, uma vez que atua sobre outros domínios. Seu objetivo é garantir as funcionalidades das aplicações desenvolvidas em outros domínios. Ao conjugar o domínio de tolerância a falhas a um outro domínio, ou seja, ao domínio de uma aplicação, o primeiro passa a se responsável pelos requisitos não-funcionais da aplicação. Os requisitos não funcionais de uma aplicação, a exemplo de confiabilidade e segurança, são cruciais em muitas aplicações e exigem métodos e conhecimentos que são distintos do domínio da aplicação. O modelo de orientação a objetos incentiva o desenvolvimento de aplicações através da composição de objetos, cada qual com a sua estrutura e comportamento específicos. Cada particular composição de objetos forma um conjunto que deve observar um comportamento que atenda aos requisitos da aplicação, de forma confiável. Com o objetivo de aumentar a confiabilidade da aplicação e de minimizar o efeito de possíveis falhas do sistema, são propostos objetos tolerantes a falhas. Objetos tolerantes a falhas são objetos responsáveis por serviços críticos da aplicação e que possuem mecanismos que garantem a confiabilidade e disponibilidade destes serviços. Comportamentos tolerantes a falhas de objetos são obtidos por redundância de componentes, incluindo replicacão e diversidade. O gerenciamento da redundância é executado de forma independente do domínio da aplicação e exercido em um meta-nível, através de técnicas de reflexão computacional. A adoção de reflexão computacional no modelo de orientação a objetos permite organizar as atividades de tolerância a falhas sem interferir no aspecto estrutural dos objetos do domínio da aplicação. Os controles que devem ser exercidos pelos meta-objetos sobre os objetos da aplicação são realizados em um meta-nível, de forma a separar as funcionalidades especificas da aplicação daquelas pertinentes ao domínio de tolerância a falhas. Estes meta-objetos, são organizados na forma de um framework, denominado MOTF - Meta-objetos para Tolerância a Falhas. O projeto de MOTF é um framework que apóia o desenvolvimento de aplicações tolerantes a falhas, compreendendo múltiplas classes que definem as funcionalidades exigidas por diversas técnicas de tolerância a falhas. Adota uma arquitetura reflexiva, na qual o meta-nível é dedicado as atividades de detecção e recuperação de erros através da monitoração de objetos da aplicação, localizados no nível base. Características de tolerância a falhas podem ser adicionadas a objetos considerados críticos pela aplicação, assim distribuindo, e não centralizando, a propriedade de tolerar falhas entre objetos da aplicação. Incorporando os princípios de reflexão computacional ao modelo de orientação a objetos dois benefícios principais se salientam: promover a reutilização de objetos tolerantes a falhas e garantir a invulnerabilidade do objeto do domínio da aplicação, ao separar as ações pertinentes ao domínio da aplicação das específicas do sistema tolerante a falhas.
Software fault-tolerance encompasses all techniques and programming languages' mechanisms intended to support the development of high reliability software. We can consider the faulttolerance area a proper domain of knowledge composed by well-defined techniques used to guarantee the reliability of applications related to other domains. Therefore, the fault-tolerance domain acts over other domains. When the fault-tolerance domain is merged into an application domain it becomes responsible for the non-functional requirements of the application. Among those requirements, reliability and safety are crucial ones and they use methods and concerns not related to the application domain. The object-oriented approach to software development allows a software to be decomposed into a set of components - the objects. Each object has its own structure and behavior. The view of a system as composed by interacting objects can be quite convenient in expressing different degrees of fault tolerance. We can distinguish between critical and non-critical objects and we may even distinguish between critical and non-critical operations within a single object. The objective of this research is the exploitation of object-oriented approach to increase reliability and decrease the effects of failures based on the provision of fault-tolerant objects. Fault-tolerant objects are abstractions of high reliability components and are designed to support several fault-tolerance strategies. Furthermore, computational reflection is adopted to organize faulttolerant activities at a meta-level and to provide transparent interfacing among fault-tolerant and non-fault-tolerant objects. A fault-tolerant object can be defined as an object that represents a single interface to redundant services and whose behavior is controlled by a metaobject. Possible behaviors of fault-tolerant objects include replication or diversity and the associated metaobject adds a specific fault-tolerant behavior to its referent object without interfering in its internal structure. MOTF - Metaobjects for Fault Tolerance is a framework intended to support the development of fault-tolerant applications. This framework consists of reusable meta-level classes. Each meta-level class implements a fault-tolerant service, and metaobjects are used as monitoring agents of fault-tolerant objects. The reflective object-oriented architecture promotes reusability and hides the programming of fault-tolerant mechanisms from the application.

É crescente, nos últimos anos, a utilização da tecnologia de orientação a objetos para a construção de sistemas complexos. A aceitação de que tal tecnologia, alem de facilitar a modularização e proporcionar maior reusabilidade, permitindo uma visão unificada dos sistemas, tem encorajado sua utilização na construção de sistemas operacionais, onde recursos do sistema e aplicações do usuário passam a ser modelados em termos da mesma abstração. Na realidade, esta nova tecnologia de desenvolvimento de software, aliada a evolução do hardware, da tecnologia de comunicações e a necessidade de um incremento qualitativo, principalmente no que diz respeito a ambientes de programação e interfaces, está provocando o surgimento de uma nova geração de sistemas operacionais, mais dinâmicos, mais flexíveis e capazes de suportar de forma transparente a presença de processamento cooperativo, distribuído ou não, heterogêneo ou não. Todavia, ainda que a literatura científica demonstre a aceitação do paradigma de orientação a objetos como um enfoque promissor a ser adotado na nova geração de sistemas operacionais, o estado atual da tecnologia de implementação e gerenciamento de objetos esta aquém da consolidação. Este trabalho surgiu neste contexto com o objetivo de contribuir na busca de um modelo apropriado ao gerenciamento de objetos e capaz de proporcionar a existência de um modelo uniforme, tanto para o nível do sistema operacional como para o nível da aplicação. O resultado da pesquisa desenvolvida foi o surgimento de um modelo estrutural orientado a objetos e baseado nas idéias da reflexão computacional, não somente como disciplina de implementação, mas como modelo conceitual para a implementação de sistemas operacionais multiprocessados.
The use of object-oriented technology for the construction of complex systems has been increasing in recent years. The assumption that such technology, besides facilitating modularization, increases reusability and maintainability, providing a unified view of the systems, has encouraged its use in building operating systems, where the system resources and the user's applications come to be modeled in terms of the same abstraction. Actually this new technology for development of software, associated with the evolution of hardware, as well as communication technology and the need for qualitative enhancement, mainly concerning programming and interface environments, is giving rise to a new generation of operating systems, more dynamic, more flexible and capable of maintaining, in a transparent way, the presence of cooperative processing, distributed or non-distributed, heterogeneous or homogeneous. However, although the scientific literature shows an acceptance of the object-oriented paradigm as a promising focus(insight) to be adopted in the new generation of operating systems, the current state of technology for object management is still far from being one of consolidation. This project has emerged in this context, with the aim of contributing to the search for an appropriate model for office management that is able to provide a uniform model, not only on the operating system level, but also on the application level. The result of the research is a new object-oriented structural model, based on the concepts of computational reflection, both as an implementation discipline and as a conceptual model for the utilization of multiprocessor operating systems. These features are very useful in developing operating systems which contain components, including resources and applications that are modeled in the same way, using object-oriented abstraction.

This thesis is concerned with a methodology for the detection of shallow (of order 1 metre) objects buried in soil using seismic waves. Possible objects of interest include infrastructure, archaeological artefacts and ordinance. A mathematical analysis of an idealised system is performed to gain understanding of both seismic wave propagation and the generation of these waves by surface sources. The mathematical techniques used in the existing analysis of a point vertical source are applied to the desired problem of a point horizontal surface traction. Results are displayed in a graphically concise form. An experimental methodology, capable of forming two-dimensional images through the ground, is described. The use of shear waves is shown preferable. The advantages and implementation of using time extended, rather than impulsive, excitation signals are described. Additional signal processing techniques, such as generalised cross-correlation functions, are also detailed. Simple numerical simulations are undertaken with the aim of both validating the post-processing algorithms and evaluating its robustness against non-ideal conditions. Simulated time histories are created by defining signals in the frequency domain and then modifying their amplitude and phase to replicate attenuation and propagation. Non-ideal conditions focus mainly on variation in the wavespeed as a function of depth. Simulations indicate that the imaging method fails for sufficiently large variations of wavespeed, particularly for objects buried below significant discontinuities in material properties. As shear waves are used for the imaging method, a source was designed and constructed to preferentially generate shear waves and was verified using field experimentation. The imaging methodology is applied to data from three experimental sites and is able to detect the target objects with some success. Problems, however, remain with the measurement of a wavespeed that is consistent and indicative of the propagation speed at depth, and in consistently obtaining a sufficiently large reflected wave from the object.

Data visualization is used in order to analyze and perceive patterns in data. One of the use cases of visualization is to graphically represent and compare simulation results. At Ericsson Research, a visualization platform, based on JavaFX 2 is used to visualize simulation results. Three configuration files are required in order to create an application based on the visualization tool: XML, FXML, and CSS. The current problem is that, in order to set up a visualization application, the three configuration files must be written by hand which is a very tedious task. The purpose of this study is to reduce the amount of work which is required to construct a visualization application by providing a serialization function which makes it possible to save the layout (FXML) of the application at run-time based solely on the scene graph. In this master’s thesis, possible frameworks that might ease the implementation of a generic FXML serialization have been investigated and the most promising alternative according to a number of evaluation metrics has been identified. Then, using a design science research method, an algorithm is proposed which is capable of generic object/bean serialization to FXML based on a number of features or requirements. Finally, the implementation results are evaluated through a set of test cases. The evaluation is composed of an analysis of the serialization results & tests and a comparison of the expected result and the actual results using unit testing and test coverage measurements. Evaluation results for each serialization function show that the results of the serialization are similar to the original files and hence the proposed algorithm provides the desired serialization functionality for the specific features of FXML needed for this platform, provided that the tests considered every aspect of the serialization functionality.
Datavisualisering används för att analysera och uppfatta mönster i data. Ett användningsfall för visualisering är att grafiskt representera och jämföra simuleringsresultat. På Ericsson Research har en visualiseringplattform för att visualisera simuleringsresultat utvecklats som baserats på JavaFX 2. Tre konfigurationsfiler krävs för att skapa en applikation baserad på denna visualiseringsplattform: XML, FXML och CSS. Det nuvarande problemet är att för att utveckla en ny applikation så måste de tre konfigurationsfilerna skrivas för hand vilket är kräver mycket utvecklingstid. Syftet med denna studie är att minska mängden arbete som krävs för att konstruera en visualiseringapplikation genom att tillhandahålla en serialiseringsfunktion som gör det möjligt att spara applikationens layout till en FXML-fil medan programmet exekverar enbart genom att extrahera information ur det grafiska gränsnittets scengraf. I detta examensarbete har ett antal mjukvarubibliotek eller API: er som kan underlätta utvecklandet av en generisk FXML serialiseringsfunktion analyserats och de mest lovande alternativen enligt ett antal utvärderingsmetriker har identifierats. Med hjälp av en iterativ, design-orienterad forskningsmetod har en algoritm designats som är kapabel till att serialisera generiska Java-objekt, eller Java-bönor till FXML. Den föreslagna algoritmen har sedan utvärderats genom automatiserade mjukvarutester. Utvärderingen består av: analys av serialiseringsresultat, design av testfall, samt jämförelse av förväntade resultat och de faktiska resultaten med hjälp av enhetstest och uppmätt kodtäckning. Utvärderingen visar att serialiseringsalgoritmen ger resultat som motsvarar de ursprungliga FXML-filerna som utformats för att verifiera olika delar av FXML standarden. Därmed anses den föreslagna serialiseringsalgoritmen uppfylla de delar av FXML-specifikationen som kravställts och beaktats i detta examensarbete.

Esta pesquisa reporta-se ao problema descrito na literatura científica como o “fracasso do ensino do cálculo”. Propusemos conhecer as noções que alunos da disciplina Cálculo Diferencial e Integral apresentam sobre limite, e também como a qualidade dessa noção ou conceito afeta a elaboração de noções sobre derivadas e integrais. Para obter essas noções, objetos de aprendizagem foram criados e disponibilizados online, em páginas de um site com domínio privado, mas de acesso aberto. Cada objeto de aprendizagem foi elaborado contendo uma situação-problema referente aos applets de cada página e um espaço de registro de respostas. Os applets abordam situações que permitem o estudo de limites, derivadas e integrais; foram elaborados no Geogebra. Os espaços de registro de respostas foram elaborados com tecnologia Google e incorporados à página do site. A metodologia consistiu na aplicação de atividades na disciplina Cálculo Diferencial e Integral. Nelas interagiram alunos e OA. As aplicações foram realizadas nas três unidades da disciplina. Para a complementação e investigação, foram feitas entrevistas inspiradas no método clínico piagetiano. Tanto os registros de respostas, quanto as entrevistas, foram autorizadas com a assinatura do termo de consentimento livre e esclarecido. Fundamenta-se a análise das respostas na Epistemologia Genética; em especial, na abstração reflexionante. A escolha deu-se devido ao caráter explicativo dessa teoria da gênese do conhecimento matemático. Os resultados demonstram que conhecimentos foram construídos em situação de interação entre alunos e OA. Várias noções foram registradas. Constatou-se, inclusive, conceituação de limite, de derivada e integral definida. Foi possível, a partir dos conhecimentos e noções apresentadas, estabelecer relações lógicas entre esses conhecimentos e, posteriormente, observar grupos com desenvolvimento cognitivo compatíveis com as relações lógicas apresentadas. O OA, com tecnologia Geogebra e Google, mostrou-se como um importante instrumento nos processos de desenvolvimento e aprendizagem do conceito de limite e dos demais conceitos da disciplina Cálculo Diferencial e Integral. Mostrou-se também como um importante instrumento para a avaliação no ambiente escolar a partir dos registros coletados.
This research refers to the problem described in the scientific literature as the "failure of calculus teaching". We propose to know the notions that students of the discipline Differential and Integral Calculus present on limit, and also how the quality of this notion or concept affects the elaboration of notions about derivatives and integrals. To get these notions, learning objects were created and made available online, on pages of a privately-owned, but open-access site. Each learning object was elaborated containing a problem situation regarding the applets of each page and a space of record of answers. The applets approach situations that allow the study of boundaries, derivatives and integrals; Were developed in Geogebra. Response log spaces were crafted using Google technology and embedded into the site page. The methodology consisted of the application of activities in the discipline Differential and Integral Calculus. In them they interacted students and OA. The applications were carried out in the three units of the discipline. For the complementation and investigation, interviews were made inspired by the Piagetian clinical method. Both the response records and the interviews were authorized with the signing of the informed consent form. It is based the analysis of the answers in the Genetic Epistemology; In particular, in reflective abstraction. The choice was due to the explanatory character of this theory of the genesis of mathematical knowledge. The results demonstrate that knowledge was built in a situation of interaction between students and OA. Several notions were recorded. It was also found a concept of limit, derivative and definite integral. It was possible, based on the knowledge and notions presented, to establish logical relations between these knowledges and, later, to observe groups with cognitive development compatible with the presented logical relations. The OA, with Geogebra and Google technology, proved to be an important instrument in the development and learning processes of the concept of boundary and other concepts of the Differential and Integral Calculus discipline. It was also shown as an important instrument for the evaluation in the school environment from the collected records.

Magister Artium - MA
The creative project is a mini-thesis. It is made up of a collection of poems, titled This Family of Things. The collection consists mainly of narrative and descriptive poems which explore the relationship between people and objects and objects and space. The poems explore the day-today experiences of a mother and her young son. The poems exhibit certain elements of the narrative poem. The poems tell a story, and there are two distinct characters and instances of dialogue. This mini-thesis also includes a reflective essay in which I discuss the functionality of objects in poetry. In the essay, I discuss the potentially of objects in creative work. I discuss to what extent objects illuminate space and how objects can potentially disrupt space. I also discuss the separation of objects and things. I discuss creative influences and the various processes involved in the formulation of the creative project.

This work concerns with dynamic evolution of applications written in Java. It investigates existing solutions implemented in both Java and other programming languages. Following part analyses complete substitution of object in running application in various situations. A framework for dynamic updating of Java-based applications is designed. The framework is implemented and is used in illustrative application. Finally, achieved results are evaluated and additional possible enhancements are stated.

In the development of autonomous vehicles, replacing the driver and its perceptive abilities is one of many technical challenges. As a part in solving these challenges, Light Detection And Ranging (LiDAR) is a promising technology. In short, LiDAR works by using lasers to detect objects in its vicinity by detecting the light that reflects on them. With knowledge of the reflective properties of an object, a prediction can be made regarding whether a certain LiDAR unit will be able to detect the object or not. When making this prediction, the common description of reflectance is often insufficient. Instead, a more complete description is given by the Bidirectional Reflectance Distribution Function (BRDF) of a surface, which describes reflection on the surface while taking the incident and reflected direction into consideration. In this thesis, an experimental setup was built with the capabilities of measuring the BRDF while taking incident and reflected polarization into account. Program software was written in Python and integrated with the hardware, providing a user interface for simple control of the setup. The BRDF was measured on a total of 6 samples; 2 reference samples and 4 samples taken from the hood of 4 different cars. Conclusively, the setup provided useful information about the reflective and polarization properties of the samples. These measurements can help in predicting whether or not a surface can be detected by a given LiDAR unit, and can also be helpful when designing new LiDAR units by providing useful information about the surfaces they are required to detect.

Os frameworks orientado a objetos oferecem um grande potencial para aumentar a produtividade e a qualidade no desenvolvimento de software. Um framework e uma infra-estrutura ou esqueleto de uma família de aplicações pertencentes a um domínio determinado. Basicamente, aplicações especificas são construídas especializando as classes do framework para fornecer a implementação de alguns métodos, enquanto a maior parte da funcionalidade da aplicação e herdada. Esta característica permite a reutilização tanto do código quanto o projeto das aplicações do domínio, o qual representa um beneficio muito significativo a respeito de outras tecnologias de reutilização. Entretanto, começar a utilizar um framework para construir aplicações especificas e complicado para um usuário que não seja o projetista do framework. Compreender um framework é frequentemente muito mais difícil que compreender bibliotecas de componentes que podem ser reutilizados independentemente. Neste caso, e suficiente compreender sua interface externa. No caso dos frameworks, para aproveitar ao Máximo as possibilidades de reutilização que oferece, e necessário compreender o projeto interno de suas classes, como essas classes colaboram entre si, bem como a forma na qual instancias dessas classes colaboram em tempo de execução. Compreender estes aspectos uma tarefa reconhecidamente complexa e demorada, sendo este e um dos fatores mais limitantes da tecnologia para ser de utilidade efetiva na produção de software. Neste trabalho, apresenta-se uma abordagem reflexiva para a construção de ferramentas de apoio a compreensão de frameworks. Esta abordagem e suportada por Luthier, um framework projetado, e implementado em Smalltalk-80, para a construção de ferramentas de analise dinâmica e visualização de programas orientados a objetos. Luthier introduz três contribuições importantes: Utilização de técnicas de reflexão computacional baseadas no conceito de gerenciadores de meta-objetos, o qual suporta a implementação de metaarquiteturas de meta-objetos especializadas para a análise de aplicações. Controle interativo do grau de detalhe das visualizações (zoom semântico) através do suporte explícito de escalas de abstração. As escalas de abstração são controladas por objetos denominados abstratores. Um abstrator permite encapsular em objetos específicos algoritmos de derivação de abstracões, filtragem e seleção de informação, bem como o controle do nível de detalhe mostrado pelas visualizações. Esta separação de funcionalidade permite implementar complexas funcionalidades de análise de programas, sem a necessidade de modificar as classes que implementam visualizações ou a representação da informação. Suporte de uma estratégia de análise orientada pela visualização da arquitetura. Esta abordagem divide o processo de compreensão em duas fases iterativa: 1) compreensão dos principais aspectos estruturais do framework a partir de da recuperação e visualização da arquitetura,; 2) análise detalhada do comportamento de instâncias envolvidas em pontos específicos da arquitetura, os quais são selecionados pelo usuário a partir da visualização arquitetônica. Luthier fornece suporte flexível para construção de ferramentas de visualização dinamicamente adaptáveis para diferentes funcionalidades de análise, através de quatro subframeworks: LuthierMOPs. o qual fornece o suporte adaptável de meta-objetos para captura de informação das aplicações analisadas; LuthierBooks que fornece suporte genérico de gerenciamento de hiperdocumentos para a representação da informação capturada e gerenciamento de livros persistentes de projeto; LuthierAbstractors, que prove suporte genérico para a derivação de abstrações da informação coletada e escalas de abstração dinamicamente variáveis; e LuthierViews, extensão do framework MVC para a construção de visualizações da informação coletada, com capacidades de manipulação direta e zooming utilizando visualizações alternativas, as quais podem ser dinamicamente selecionadas pelo usuário. Com o suporte fornecido por Luthier, uma ferramenta, especialmente projetada para apoiar a compreensão de frameworks a partir da analise de exemplos, foi desenvolvida. Esta ferramenta fornece um conjunto de visualizações estruturais, com capacidade de animação de fluxo de controle do framework, bem como visualizações alternativas de subsistemas e padrões de projeto. Estas abstrações são reconhecidas através da análise da informação coletada dos exemplos analisados. Através das visualizações providas, o usuário pode explorar um dado framework através de mecanismos de navegação entre diferentes representações visuais, bem como filtragem e consulta acerca de informação relevante a ser visualizada. Este mecanismos são integrados com mecanismos de zoom semântico que habilitam a visualização da informação em diferentes níveis de abstração. Através da representação de hiperdocumento, a ferramenta suporta a construção manual, bem como a geração automática em alguns casos, de livros persistentes de documentação, com capacidade de edição, de importação de diagramas produzidos pelas visualizações, e de navegação sobre diferentes livros e o código fonte do framework. Esta características habilita a geração de documentação durante o processo de compreensão, facilidade não disponível, habitualmente, nas ferramentas de compreensão desenvolvidas até hoje. A capacidade de Luthier para a construção de ferramentas foi testada com a construção de outras ferramentas, como por exemplo, depuradores visuais e de coleta de métricas. A viabilidade e eficácia da abordagem foi testada através de experimentos, os quais mostraram que grupos utilizando a ferramenta de apoio produziram aplicações com maior nível de reutilização do framework que grupos de usuários não utilizando a ferramenta.
Object-oriented frameworks are a powerful reuse technique for building applications in a given domain. A framework works as a template or skeleton for building applications, being composed of a set of classes abstracting the general characteristics of an application domain. Building a specific application requires the specialization of some classes that provide the implementation of methods that will complete the necessary behaviour, while the global control structure is given by the framework. Frameworks offer a great potential to increase the productivity and quality in software development. However, starting to use a framework to build a specific application is complicated for any user other than a framework designer. Understanding a framework is frequently much harder than understanding libraries of components that can be reused independently. To adequately reuse isolated classes of a class library, it is sufficient to understand their external interface. In case of a framework, in contrast, to take full advantage of the services provided, it is necessary to understand the way its classes collaborate, as well as the internal design of some of them. These classes code the complex behaviour of a network of instances dynamically created. Therefore, it is often needed not only to understand how the classes are organized in static inheritance hierarchies, but also how instances collaborate at runtime. This work presents a reflective approach for the construction of tools for framework comprehension. This approach is supported by Luthier, a framework designed, and implemented in Smalltalk-80, which provides a flexible support for building tools for the dynamic analysis and visualization of object-oriented programs. Luthier introduces three important contributions: The use of computational reflection techniques, based on the concept of meta-object managers, which support the implementation of specialized meta-object-based metaarchitectures for the dynamic analysis of applications Support for building visualizations with different levels of abstraction under interactive control of the user (semantic zoom) through the explicit support of abstraction scales. Abstraction scales are controlled by objects called abstractors, which allow the encapsulation, in specific objects, of algorithms for abstraction derivation, filtering and information selection, as well as the interactive control of the detail level to be shown by visualizations. This separation of concerns enables the implementation of complex program analysis functionalities without the need of modifying classes implementing visualizations or information representation. Support for an architecture-driven analysis strategy. This approach divides the understanding process in two iterative phases: I) comprehension of the global structural and behavioural aspects of the framework from the recovery and visualization of its architecture.; 2) detailed analysis of specific instances involved in particular points of the architecture, selected by the user form the architectural view. Luthier provides a flexible support for the construction of visualization tools dynamically adaptable to different analysis functionalities through four sub-frameworks: LuthierMOPs, which provides an adaptable support of meta-objects for information gathering from the analyzed applications; LuthierBooks, which provides generic support for hyperdocument management to represent captured information and management of persistent design books: LuthierAbstractors, which provides generic support for the derivation of abstractions and dynamically variable abstraction-scales: and LuthierViews. extension of the MVC framework for the construction visualizations of the captured information, with capabilities of direct manipulation and zooming using alternative visualizations, dynamically selected by the user. With the support provided by Luthier a tool, specially designed to support framework comprehension from analysis of examples, was developed. This tool provides a set of structural visualizations with control-flow animation capabilities, as well as alternative visualizations of subsystems and design patterns, recognized through the analysis of information gathered from examples. Through these visualizations the user can explore a given framework by using mechanisms for navigating among different visual representations, as well as information filtering and queries about relevant information to be visualized. These functionalities are fully integrated with semantic zoom mechanisms that enable information visualization at different levels of abstraction. With the hyperdocument support, the tool allows for manual construction, as well as automatic generation in some cases, of persistent documentation books. These books offers editing capabilities, importation of diagrams from visualizations, as well as navigation through different books and through the source code of the analyzed framework.. These characteristics allows the support of additional documentation generation during the comprehension process, facility which is not normally available in current understanding tools. The capabilities for tool construction supported by Luthier were tested through the development of different tools, such as, visual debuggers and metrics collectors. The viability of the approach was tested through experiments. These experiments suggest that users using the understanding tool produce applications with a greater re-use level than groups of users not using it.

A manutenção de software a uma realidade presente em todos os sistemas de computação, gerando a necessidade de novas versões que alterem as funcionalidades existentes no software ou adicionem novas. Particularmente, sistemas de tempo-real nem sempre podem ser descontinuados tomando-se indisponíveis para realizar a instalação de uma nova versão. Tais sistemas evidenciam a necessidade de substituição de componentes, representados por funções, procedimentos, módulos ou objetos, durante o processo de execução do programa ou sistema. Outrossim, apos ser realizada a substituição da versão, o componente não pode apresentar falha sob pena de comprometer o fornecimento dos seus serviços. Portanto. constata-se a importância de novas técnicas de manutenção de software que não prejudiquem a sua disponibilidade e confiabilidade. A abordagem aqui proposta a utilizar uma arquitetura reflexiva aliada a técnicas típicas do domínio da tolerância a falhas para promover a separação entre as atividades de substituição e validação de componentes e as funcionalidades executadas pelo pr6prio componente. No decorrer deste trabalho são apresentados diversos cenários de sistemas que podem se beneficiar da troca dinâmica de componentes e abordadas varias facetas do problema de substituição. A proposta a apoiada por um estudo de caso, implementado na linguagem de programação Java e seus diferentes protocolos de reflexão computacional.
Software maintenance is a present reality in all computational systems. This demands the frequent installation of new versions. Usually, real-time systems cannot be interrupted to install a new version. For such systems, the replacement of components, represented by functions, procedures, modulus or objects, must be performed during the execution of the program or system. Even when the old version has been replaced, the new one should not contain faults that could invalidate its services. Therefore, we need new software maintenance techniques that can mantain the system availability and realibility. The approach proposed here consists in using a reflective architecture along with techniques which are typical of the fault tolerant domain. The procedure is carried out by keeping a clear separation between validation activities and the functions executed by the component itself. We present several scenarios to which the dynamical exchange of components can be applied. Different aspects of the replacing issue are also addressed. The proposal is supported by a specific application which has been implemented in the Java language and its different protocols of computational reflection.

Mass spectrometry imaging (MSI) is a powerful tool that provides mass-specific surface images with micron or sub-micron spatial resolutions. In a microscope MSI experiment, large sample surfaces are illuminated with a defocused laser or primary ion beam, enabling all surface molecules to be desorbed and ionised simultaneously before being electrostatically projected onto a position-sensitive imaging detector at the end of a time-of-flight mass analyser. Traditionally only the image of one mass-to-charge ratio can be obtained in a single acquisition, which limits its applicability. However, the development of event-triggered sensors, such as CMOS-based cameras, revives the microscope MSI method by allowing multi-mass imaging. Therefore, the challenges facing microscope have MSI shifted to improving its mass resolution, effective mass range, and mass accuracy. This thesis proposes effective solutions to each of them, and thus significantly improves the performance and applicability of microscope MSI. To increase the mass range, two modified post-extraction differential acceleration (PEDA) techniques, double-field PEDA and time-variable PEDA, were used to demonstrate mass-resolved stigmatic imaging over a broad m/z range. In double-field PEDA, a potential energy cusp was introduced into the ion acceleration region of an imaging mass spectrometer, creating two m/z foci that were tuned to overlap at the detector plane. This resulted in two focused m/z distributions that stretched the mass-resolved window with m/Δm >= 1000 to 165 Da without any loss in image quality; a range that doubled the 65 Da achieved under similar conditions using the original PEDA technique. In time-variable PEDA, a dynamic pulsed electric field was used to maximize the effective mass range of PEDA. By simultaneously focusing ions between 300 to 700 m/z using an exponentially rising voltage pulse, time-variable PEDA provides an effective mass range more than six times wider than the original PEDA method. Although reflectrons are widely used to improve the mass resolving power of ToF-MS, incorporating them in a microscope MSI instrument is novel. A reflectron MSI instrument was designed and implemented. Simulations demonstrated that one-stage gridless reflectrons were more compatible with the spatial imaging goal of the microscope MSI instrument than the gridded reflectrons. Preliminary experimental results showed that coupling the gridless reflectron with single-field PEDA achieved a mass resolution above 8,000 m/Δm while keeping a spatial resolution of 20 um. In conclusion, the gridless reflectron was able to triple the mass resolving power without losing any spatial imaging power. The poor mass accuracy hurdle was overcome by machine learning algorithms, which can construct clinical diagnostic models that recognise the peak pattern of biological mass spectra and classify them accurately without knowing the actual mass of each peak. After a proof of concept "experiment", where the mass spectra of dye molecules were classified by various learning algorithms, three pairs of datasets (ovarian cancer, prostate cancer, chronic fatigue and their respective controls) were used to build classifiers that accurately distinguish blood samples from controls. Possible biomarkers were also discovered by evaluating the importance of each m/z feature, which may assist further studies.

This dissertation engages with contemporary interpretations of Nietzsche and Heidegger on the issue of self-knowing with respect to the notions of honesty and authenticity. Accounting for the two philosophers' developing conceptions of these notions allows a response to interpreters who conceive the activity of self-knowing as a primarily personal problem. The alternative accounts proposed take as a point of departure transitional texts that reveal both thinkers to be engaged in processes of revision. The reading of honesty in Chapters 1 and 2 revolves around Nietzsche's groundwork on prejudice in Morgenröthe (1880-81), where he first problematizes the moral-historical forces entailed in actuating the 'will to truth'. The reading of authenticity in Chapters 3 and 4 revolves around Heidegger's lectures on what motivates one's thinking in Was heißt Denken? (1951-52). The lectures call into question his previous formal suppositions on what calls forth one's 'will-to-have-a-conscience', in an interpretation of Parmenides on the issue of thought's linguistic determination, discussed further in the context of Unterwegs zur Sprache (1950-59). Chapter 5 shows how Heidegger's confrontation with Nietzsche contributed to his ongoing revisions to the notion of authenticity, and to the attending conceptions of critique and its authority. Particular attention is given to the specific purposes to which distinct Nietzschean foils are put near the confrontation's beginning--in Heidegger's lectures on Nietzsche's second Unzeitgemässe Betrachtung (1938), and in the monograph entitled Besinnung (1939) which they prepare--and near its end, in the interpretation of Also Sprach Zarathustra (1883-85) presented in the first half of Was heißt Denken? Chapter 6 recapitulates the developments traced from the vantage point of the retrospective texts Die Zollikoner Seminare (1959-72) and the fifth Book of Die fröhliche Wissenschaft (1887). Closing remarks are made in relation to recent empirical research on the socio-environmental structures involved in determining self-identity.

Free-space optics (FSO), or wireless optical communications, has received extensive research due to its promise of practically limitless bandwidths. However, FSO has challenges yet to be met for a cost effective realisation. This D.Phil thesis explores a solution using a ferro-electric liquid crystal spatial light modulator (FLC SLM) and binary phase holograms to significantly reduce the hardware complexity of an FSO system with auto-alignment and turbulence compensation. The theory of binary phase hologram is presented and extended to obtain a new algorithm that is suitable for a FLC SLM. The algorithm is able to be used in a demonstration system to broadcast data streams to multiple receivers, showing the capability of using FLC SLM to form any beam configuration. An FSO transmitter is then developed that uses retro-reflectors as markers for the receivers. The transmitter combines an imaging system with the FLC SLM as a reconfigurable beam steering system for acquiring the retro-reflector location. The FLC SLM is also used to reduce aberrations in the optics, resulting in a significant increase in the transmitted beam power density. The accuracy of the acquisition is measured to give a small steering error without the use of a closed loop controller. An optical turbulence simulator, using the principals of binary phase hologram, is constructed to simulate optical beam propagation in turbulent conditions. The simulator accurately produces aberrations that have the same statistics with the theoretical prediction. Analysis of the phase distortion due to turbulence is performed and a wavefront sensorless turbulence compensation method based on the FLC SLM gives significant reduction in calculated bit error rates. New scintillation index derivation for multiple optical beams is described and then used to demonstrate further decrease in bit error rates.

This thesis explores the transformation of the mirror's symbolic role in the poetry and visual art of late nineteenth-century Paris. For centuries the mirror has been associated with both truth and artifice, whether in religion, popular culture, art, or theories of aesthetics. In the context of nineteenth-century literature, M.H. Abrams uses the mirror to represent the age-old idea of the artist as an objective reflector of the world, juxtaposing this with the nineteenth-century notion of the artist as a subjective lamp. However, this thesis shows that, far from being abandoned as a symbol of artistic expression, the mirror motif was reclaimed and reinterpreted by Baudelaire and his artistic and poetic successors. The thesis argues that their works highlight the distortions and ambiguities that the mirror can produce, using it as a motif to challenge and alter our mode of vision. This thesis focuses on the visual and poetic culture of Paris between 1850 and 1900, when mirrors were increasingly visible in a range of public and private settings. Building on Walter Benjamin's descriptions of Paris as a city of mirrors and a locus of multiple, shifting gazes, the thesis examines how the perceptual experiences of modernity feed into the development of the mirror's symbolic role. Through a series of close readings, the thesis analyses the dynamics of mirror-vision and explores the shared preoccupations of art and poetry in their treatment of subjectivity, vision, and self-reflexive artistic practices. The thesis is arranged into three sections, examining texts by Charles Baudelaire, Henri de Régnier, Jules Laforgue, Stéphane Mallarmé, and Marie Krysinska, and artworks by Edgar Degas, Edouard Manet, Henri de Toulouse-Lautrec, Berthe Morisot, and Mary Cassatt. The first section assesses Baudelaire's works as a turning point for the mirror's symbolic significance, particularly examining how Baudelaire reinterprets the association between mirrors and femininity. The second section explores this latter connection in the art and poetry of Baudelaire's late nineteenthcentury successors. The third section examines the mirror's appearance in various ambiguous or ill-defined spaces, assessing how this affects the reader's or viewer's perceptions. I conclude that in the art and poetry of this period, the mirror becomes an emblem of self-reflexivity. Through works that prioritise mobility, multiplicity, and fragmentation, these artists and poets subvert the mirror's associations with mimesis in order to expose the dynamic uncertainty of vision and artistic representation.

This thesis examines organizational programmes designed to manage racial identities in the South African workplace. It focuses on race-based affirmative action (AA) programmes. The AA debate has become a proxy for a more fundamental contest over the political boundaries of legitimate action and discourse. Notwithstanding pockets of resistance, there is consensus (amongst business leaders) on the need for AA policies. This is explained, in part, by post-1994 shifts in the boundaries of legitimacy. Rejection of AA is no longer a legitimate course of action. The AA controversy seems to be serving as a litmus test for the state of race relations in SA. The political transition has been accompanied by attempts to reconstitute political identities. It is suggested that the language of Africanism is providing the conceptual grammar with which to understand these processes. Race has become the primary axis through which an African identity, apposite to the 1990s, is being theorized. In the face of economic uncertainty and inequality the temptation is to naturalize identities. Hence the appeal of strictly defined race-based AA programmes. Despite the moral lexicon which has sprung up around AA, many companies are arguing that AA makes good business sense. It is needed to meet changes in the demographic profile of the consumer and supplier markets. The political and legislative imperative to implement AA means that companies need to make sense of it economically. This is not to suggest that managers are simply having to make a leap of faith with regards to AA. The issue is more complex: whilst many are making a virtue out of necessity, this necessity may prove to have its virtues. AA programmes cannot be understood in isolation from the economic 'realities' that enable, shape and constrain them. Given these adverse economic conditions, AA will, in all likelihood, have limited individual impact. At most, its gains will be modest. It will not eliminate the apartheid legacy of racial and gender inequalities, nor can it alone overcome the effects of other economic forces. AA needs to be located within a broader policy agenda aimed at promoting economic equity. It is in this respect that it has the potential to be an effective policy tool.

The Gorringe Bank region is located at the eastern end of the Azores-Gibraltar plate boundary, which plate kinematic studies show to progressively change from extension at the Azores, through pure right lateral strike slip at the Gloria fault to compression at Gibraltar. The region is dominated by high relief (4-5 km), highly deformed, uncompensated, ENE-WSW trending seamounts and intervening abyssal plains with basin sediment thicknesses in excess of 4 km and minimal surface deformation. Gorringe Bank, which was formed by overthrusting of the African plate upon the Eurasian plate at about 10 Ma along the plate boundary, is supported in part by exure of the Eurasian plate, as indicated by pre-loading sediments and basement to the north which are tilted towards Gorringe Bank. Broken plate models show the Eurasian plate to have an elastic thickness of about 35 km which is in agreement with that expected for the crustal age (130-135 Ma) at the time of loading. Coral Patch Ridge was formed by a combination of thrust faulting and whole crustal buckling resulting from the past 20 Ma compression and was partially uplifted before deposition of an olistostrome in the Middle Miocene. Recent compressional deformation is distributed over a wide region, as indicated by the dispersed shallow seismicity and has a trend which rotates from approximately N45oE to N70oE from west to east across the region, near perpendicular to westward verging plate motion vectors. The majority of extensional and strike-slip deformation is explained by a regional strike-slip strain ellipse model, including an antithetic NNE-SSW strike slip fault between Gettysburg and Hirondelle seamounts which marks the boundary between the Eastern and Western Horseshoe Basins. Isostatic models for the Madeira-Tore Rise, which initially formed at the Mid Atlantic Ridge, give an elastic thickness of approximately 15 km indicating that significant material was added to the Rise as it moved away from the Ridge.

Les utilisateurs s'attendent à ce que les logiciels soient à la fois continuellement disponibles et mis-à-jour à la volée. L'introduction de nouvelles fonctionnalités et l'intégration de correctifs ne doit pas perturber la bonne marche d'une application. Les développeurs bénéficient aussi de la modification dynamique des logiciels en adaptant le code à de nouvelle situations ou bien an exécutant des analyses dynamiques à des fins de monitorage, de déboguage et d’optimisation. Les langages de programmation doivent donc fournir aux développeurs des mécanismes qui améliorent l'adaptabilité logicielle. Dans le même temps, l'augmentation de la taille et de la complexité des logiciels requièrent des applications faites de nombreux composants développés par différents groupes. Dans ce contexte chaque composant doit être convenablement protégé des autres. Les langages de programmation doivent donc aussi fournir des mécanismes qui améliorent l'encapsulation. Le besoin de supporter des adaptations dynamiques d'un côté, et le besoin d'avoir des composants convenablement confinés d'un autre, poussent la conception des langages de programmation dans deux directions opposées: soit plus de flexibilité, soit plus de contrôle. Cette dissertation étudie cette tension dans le contexte des langages orientée-objet dynamiquement typés via deux mécanismes qui promeuvent l'adaptabilité logicielle: la réflexion et les méthodes d’extension. Pour chacun de ces mécanismes, nous démontrons leur utilité, leurs effets néfastes sur l'encapsulation et proposons des solutions qui conservent leurs forces tout en maintenant l'encapsulation
Users expect modern software to be both continually available and updated on the fly. Introduction of new features and integration of bug fixes should not trouble the smooth running of an application. Developers also benefit from dynamic modifications of software by adapting code to new unanticipated situations or by running dynamic analyses to get feedback about the behavior of running applications for monitoring, debugging and optimization purposes. Programming languages should thus provides developers with mechanisms that improve software adaptability. At the same time, the increasing size and complexity of software call for applications made up of many interacting components developed by different parties. In this context, each component needs to be properly protected from other ones. Programming languages should thus provide developers with mechanisms that improve encapsulation. The need for dynamic adaptations on the one hand and the need for properly confined components on the other hand pulls programming language design in two opposite directions: either more flexi-bility or more control.This dissertation studies this tension in the context of dynamically-typed object-oriented languages with two language mechanisms that promote software adaptability: reflection and extension meth-ods. For both mechanisms, we demonstrate their usefulness, their harmful effect on encapsulation and propose solutions to retain their power while maintaining encapsulation

This thesis critically appraises the theological legitimacy of theories of divine action (TDAs) posited by four principal contributors to the VO/CTNS series "Scientific Perspectives on Divine Action." Wesley Wildman is chosen for his staunch apophaticism; Robert Russell because of his appeal to objective and noninterventionist divine action and his ontology of quantum indeterminism; John Polkinghorne because of his reliance on kenotic theology to underpin free-process theodicy and his ontology of chaotic systems; and William Stoeger for his interpretation of primary/secondary cause. This engagement broadly matches what Philip Clayton, in the series' final volume, labels an "evangelical-theist or orthodoxtheist" (e-t/o-t) theological perspective. This is a perspective Clayton argues the project otherwise lacks. The thesis proposes that, from this (e-t/o-t) perspective, each of these individuals' contributions to the series proves theologically difficult in some degree. It argues that Wildman's apophatic rejection of Revelation and personal analogy and his reliance on the anthropology of the Modern Secular Interpretation of Humanity (MSIH) is too stark and, ultimately, too anthropocentric. Russell's theory of noninterventionist objective special divine action (NIODA) is theologically difficult in the context of creatio ex nihilo, because it rests on the problematic distinction between 'general' and 'special' divine action (GDA/SDA), and a problematic ontology of quantum indeterminism. John Polkinghorne might be expected to provide the kind of theological perspective Clayton says is absent, but aspects of his approach rest on a theologically problematic interpretation of kenosis and a 'free-process' analogy that entails a developmentalist and process-theological metaphysical interpretation of evil. This thesis determines that conflicts at the heart of the VO/CTNS series' debate revolve around two primary tensions. The first tension concerns the scope of 'methodological-naturalism'. The second tension concerns the philosophical nature of 'cause'. Mapping the linguistic, historical, philosophical, and sociological background influences that impact all theological perspectives in the VO/CTNS series at an intentionally broad scale provides the deep context needed to establish not only 'how?' but also 'why?' these tensions culminated in the series' marginalisation of the traditional (e-t/o-t) perspective on divine action. The thesis therefore concludes that Clayton is correct to assert that the (e-t/o-t) theological perspective is missing from the VO/CTNS series. The thesis also concludes, however, that when these tensions are adequately contextualised, that marginalisation proves philosophically unnecessary as well as theologically undesirable and that Clayton's own demand for theological 'traction' through scientific constraint is too metaphysically restrictive. Methodological-naturalism prohibits, at least in practice, a 'theology of nature', permitting only a 'natural theology' in some key respects. This much broader background context also allows us to recognise the influences of what Charles Taylor calls "cross pressures" that have driven secularisation. These tensions clash conspicuously in the "problem of evil" which cannot be bracketed off from the task of theological reflection on the series. Contextualising these tensions in relation to both 'evil' and the VO/CTNS series' methodological ambitions, highlights the significance of sociological as well as rational influences on individual choices of theological perspective. The meaning of 'cause' and the scope of methodological-naturalism together form a philosophical and theological locus for the series. Closer investigation of this locus reveals that Russell's and Polkinghorne's contributions to the VO/CTNS series suggest a univocal interpretation of 'cause' and 'freedom' that departs from both the "two languages" perspective of Stoeger's Catholicism and Protestant neo-Orthodoxy. This, raises the important question whether some perspectives in the series represent what, by Nancey Murphy's criteria, represents an ipso facto change of theological tradition. A change that marks an important distinction between Russell's and Polkinghorne's perspective on divine action and the (e-t/o-t) theological perspective that Polkinghorne, especially, might be thought by some to have represented. Having demonstrated that Clayton is, in fact, correct to argue that the (e-t/o-t) theological perspective is indeed missing in the VO/CTNS series, the thesis seeks a more overtly theological perspective on divine action by engaging positively with Vernon White. In view of the various demands for any theologically adequate (e-t/o-t) TDA; now more fully clarified in the broad perspective provided by earlier chapters; it finds White's TDA of universal special divine action (USDA) theologically credible and convincing. That is because White's perspective embodies the three elements that this thesis concludes are vital for any adequate theological perspective on divine action: the need to mind three kinds of gap; the ontological gap between immanent creation and the transcendent Creator; the immanent gap between methodologicalnatural 'data' and the full gamut of human experience; and, finally, the gaps that exist, as Rowan Williams so evocatively phrases things, at "the edge of words". Discussion of divine action demands a careful accounting of the way we use language. Neither univocal nor equivocal speech can disclose divine action "well". What is required instead, is careful and painstaking attention to the work we are asking words to perform in representing divine action truthfully. Attention to the meaning of words like 'model', 'cause', 'methodological-natural', and 'freedom'. The thesis concludes that, with these three elements in place and correctly aligned, the strengths and weaknesses of the VO/CTNS series come more clearly into view and that, far from signalling a "crisis" for contemporary theology, this broader context shows the route to a credible TDA from the (e-t/o-t) perspective, if navigated with proper methodological care, remains navigable for anyone wishing, still, to travel that way. Chapter Outline Since we cannot map what cannot be recognised or represented, chapter 1 queries the role of language per se for representing, truthfully, Divinity and transcendence. Tensions prove to be inherent to the way we use words, and their capacity to intimate transcendence is illustrated by juxtaposing Rowan Williams' exploration of "the edge of words" with Nicholas Saunders bleak assessment that the VO/CTNS signifies a "crisis" for contemporary theology. This chapter suggests why Saunders may have been driven to such a bold, if negative, viewpoint, concluding that, however unavoidably provisional and partial language remains, it is metaphysically possible to ground the claim that speech about God can be truthful. It then tentatively explores how best to frame that speech, investigating the role of certain tropes and a tension that resides in the semantic fluidity of "critical-realism". This flexibility means that the apparently univocal use of the word 'model' may mask differing epistemologies of the word for the scientist and the theologian. The ambiguity in the relationship between model and metaphor is then employed to evaluate the role that "causal joint" plays in framing the science-theology debate over divine action.

E-government services in the form of information systems (IS) artifacts create a new arena for co-creation that governments aim to leverage. Design of and knowledge about IS artifacts in value co-creation in e-government can thereby be considered valuable for the future development of e-government. How IS artifacts are used in value co-creation and co-destruction and how the artifacts are developed is however not well understood. This thesis addresses the problem of how to design for and understand value co-creation in e-government. To address the problem stated, three research questions are posed. (i) How can IS artifacts be designed to enable value co-creation in e-government and what aspects can inhibit value being co-created through the designed artifacts? (ii) How can boundary object theory facilitate the understanding of IS artifacts used in value co-creation and co-destruction in e-government? (iii) How can retrospectives in design science contribute to research on value co-creation in e-government? Two artifacts in the form of instantiations are designed and evaluated. Design science research methodology is used in two different projects at Swedish municipalities. Secondary analysis is used to identify aspects that inhibit value being co-created through the designed IS artifacts. From these inhibitors, core aspects for public value co-creation are derived. Thereafter, this thesis delves further into how IS artifacts are used in collaborations between citizens, private businesses, and government agencies in order to co-create value. Two case studies are carried out at Swedish government agencies and sociomaterial boundary object theory is used to enhance understanding. The thesis research process ends with a retrospective evaluation of the performed research, using critical realism as its philosophical foundation and guidance. The result includes one configurable process model that enables value co-creation by facilitating shared understanding between collaborating parties; one mobile service that enables value co-creation through citizen sourcing; aspects that inhibit the realization of co-created value; and four core aspects that need to be considered when designing artifacts for value co-creation. That IS artifacts can be regarded as boundary objects when you aim to study and understand value co-creation and co-destruction between communities in e-government. Descriptions of how IS artifacts, viewed as sociomaterial boundary objects, are used in value co-creation processes between governments, citizens, and businesses and outcomes in terms of value co-creation and co-destruction. The benefit of performing critical realism-guided retrospectives in design science in order to complement prescriptive knowledge with explanatory and critical knowledge is motivated. It is showed that the design of artifacts generates knowledge through the design efforts, regardless of whether they also yield utility. This thesis contributes to e-government research and practice with knowledge on how to design artifacts that enable value co-creation. Establishes sociomaterial boundary object theory as a theoretical lens that offers a tool to evaluate and design IS artifacts that enable value co-creation and with knowledge on how IS artifacts are used in value co-creation. The thesis also motivates the usefulness of retrospective evaluation in design science. Suggestions for future research include further developing design science retrospectives.

At the time of the doctoral defense, the following paper was unpublished and had a status as follows: Paper 6: Manuscript.

In this research paper, it evaluates the benefits achievable from static testing framework by analyzing and transforming the JUnit3.8 source code and static execution of transformed code. Static structure enables us to analyze the code statically during creation and execution of test cases. The concept of research is by now well established in static analysis and testing development. The research approach is also increasingly affecting the static testing process and such research oriented work has proved particularly valuable for those of us who want to understand the reflective behavior of JUnit3.8 Framework.

JUnit3.8 Framework uses Java Reflection API to invoke core functionality (test cases creation and execution) dynamically. However, Java Reflection API allows developers to access and modify structure and behavior of a program.  Reflection provides flexible solution for creating test cases and controlling the execution of test cases. Java reflection helps to encapsulate test cases in a single object representing the test suite. It also helps to associate each test method with a test object. Where reflection is a powerful tool to perform potential operations, on the other hand, it limits static analysis. Static analysis tools often cannot work effectively with reflection.

In order to avoid the reflection, Static Testing Framework provides a static platform to analyze the JUnit3.8 source code and transform it into non-reflective version that emulates the dynamic behavior of JUnit3.8. The transformed source code has possible leverage to replace reflection with static code and does same things in an execution environment of Static Testing Framework that reflection does in JUnit3.8. More besides, the transformed code also enables execution environment of Static Testing Framework to run test methods statically. In order to measure the degree of efficiency, the implemented tool is evaluated. The evaluation of Static Testing Framework draws results for different Java projects and these statistical data is compared with JUnit3.8 results to measure the effectiveness of Static Testing Framework. As a result of evaluation, STF can be used for static creation and execution of test cases up to JUnit3.8 where test cases are not creating within a test class and where real definition of constructors is not required. These problems can be dealt as future work by introducing a middle layer to execute test fixtures for each test method and by generating test classes as per real definition of constructors.

A abordagem de linha de produtos de software oferece benefícios ao desenvolvimento de software como economia, qualidade e desenvolvimento rápido, pois se baseia em reuso de arquitetura de software mais planejado e direcionado a um domínio específico. Neste contexto, o gerenciamento da variabilidade é uma questão chave e desafiadora, já que esta atividade auxilia a identificação, projeto e implementação dos novos produtos derivados da linha de produtos de software. O objetivo deste trabalho é definir um processo de gerenciamento de variabilidade de linha de produtos de software. Este processo, denominado GVLPS, identifica a variabilidade, extraindo as variantes a partir de diagramas de casos de uso e modelando-as através de features, especifica a variabilidade identificada e utiliza como suporte, na criação de variantes, um mecanismo de variabilidade baseado em modelos de objetos adaptáveis e em reflexão. A aplicação do processo é realizada através de um estudo de caso sobre o software de um veículo espacial hipotético, o Lançador de Satélites Brasileiro (LSB).
The Software Product Line approach offers benefits such as savings, large-scale productivity and increased product quality to the software development because it is based on software architecture reuse which is more planned and aimed to a specific domain. The management of variability is a key and challenging issue, since this activity helps identifying, designing and implementing new products derived from software products line. This work defines a process for the variability management of software product line, called GVLPS. After modeling the variability, extracting the variants from use case diagrams and features, the next step is to specify the variability that was identified. Finally, the proposed process uses a variability mechanism based on adaptive object model and reflection as support in the creation of variants. The proposed process uses as case study the software system of a hypothetic space vehicle, the Brazilian Satellites Launcher (LSB).

This thesis concentrates on physically based simulation of fluids followed by its photorealistic visualization. It describes one form of Smooth Particle Hydrodynamics methods for viscoelastic fluid simulation and includes its extension for multiple interacting fluids. It also deals with SPH boundary problem and investigates its solution by fixed boundary particles. For visualization of fluids there is a method of Ray Tracing described in detail and it's extended with light absorption in transparent materials. In connection with this method there is also discussed a problem of infinite total reflections and some solution techniques are offered. To extract the surface of the fluid there is used a Marching cubes method and its discussed in terms of Ray Tracing.

The Dynamic Unity of Writing (DUW) offers an object oriented theory of writing, based on the idea of a dynamic unit, which is the simultaneous manifestation of distinct thought processes acting as one. This thesis demonstrates how writing, while grounded in consciousness, fulfills the four characteristics of a dynamic unit: that in its unity of action, writing is a basic level structure; that writing is more than the sum of its parts; that it is observable only in a context of operation; and, that writing exhibits a pattern of correlation across elements. This theory blends the four elements of the DUW (self, technology, style, and process) as an approach to understanding the roles of exigence and emergence in textual coherence and in both a writer’s and writing’s development. As a self-reflective tool, the DUW offers a framework through which writers can self-identify areas of intervention where further development of an element or elements of writing can result in an improvement of writing skills.