Dissertations / Theses on the topic 'Action Stars'

Contact between numerical simulations and observations of stellar magnetism is sought, with an emphasis on those stars that are the most readily observed and those that may have magnetic activity cycles: the Sun, F-type, and B-type stars. Two approaches are taken in studying stellar dynamos and dynamics, utilizing three-dimensional MHD simulations run on massively parallel supercomputers with the full spherical geometry and employing a new compressible code in the spherical wedge geometry. A 3-D MHD simulation of the solar dynamo that utilizes the Anelastic Spherical Harmonic (ASH) code is presented. This simulation self-consistently exhibits four prominent aspects of solar magnetism: activity cycles, polarity cycles, the equatorward field migration, and grand minima. The ASH framework and this simulation's ability to capture many aspects of the solar dynamo represent a first step toward a more complete model of the Sun's global-scale magnetic activity and its cycles. The dynamics and dynamos of F-type stars are studied through global-scale ASH simulations, with significant contact made between the observed differential rotation and magnetic cycle periods of these stars and those achieved in the simulations. Separately, ASH simulations of core convection in the massive B-type stars show that generation of superequipartition magnetic fields with peak strengths above 1 MG is possible within their cores, which has implications for the evolution of these stars as well as for the properties of their remnants. The internal waves excited by overshooting convection and rotation in these star's radiative exteriors are assessed for their asteroseismic signatures. The results of 3-D compressive MHD simulations of the solar near-surface shear layer with the Compressible Spherical Segment (CSS) code are shown, with such layers arising in the coupled dynamics of ASH and CSS as well as in a more rapidly rotating, thin convective envelope of an F-type star.

In this thesis we study the properties of strongly-coupled large-N conformal field theories (CFT’s) using AdS/CFT correspondence. Chapter 1 serves as an introduction. In Chapter 2 we study the shear viscosity of strongly-coupled large-N conformal field theories. We find that it is affected by \(R^2\) corrections to the AdS action and present an example of 4D theory in which the the conjectured universal lower bound on viscosity-to-entropy ratio \(\eta/s > 1/4 \pi\) is violated by 1/N corrections. This fact proves that there is no universal lower bound of \(1/4 \pi\) on viscosity-to-entropy ratio and may be relevant for the studies of QCD quark-gluon plasma for which this ratio is experimentally found to be close to \(1/4 \pi\). In Chapter 3 we study the formation of the electron star in 4D AdS space. We show that in a gravity theory with charged fermions a layer of charged fermion fluid may form at a finite distance from the charged black hole. We show that these “electron stars” are candidate gravity duals for strongly interacting fermion systems at finite density and finite temperature. Entropy density for such systems scales as \(s \sim T^{2/z}\) at low temperatures as expected from IR criticality of electron stars solutions.
Physics

How can an idea that critiques the global capitalist system persist? How can a concept that opposes growth as indicator of wealth gather more and more supporters inside and outside of academia? How can a radical theory that challenges almost any societal structure convince us that it is something we must pursue? The Degrowth movement is often referred to as utopia, and not without good reason, as it is a relatively new concept that certainly still has its flaws. This thesis aims to start the Degrowth dialogue outside the ivory tower of academia. We use qualitative data gained from five focus groups to determine which components of Degrowth need the most clarification to make a movement evolve into a genuine theory. Our findings, brought forward by engaged discussions during the focus groups, showed potential for improvements of the Degrowth theory in the areas of education, societal norms and values as well as governmental policies and regulations. These insights allowed us to more specifically address the ambiguities of degrowth and counter them with opinions from experts to make Degrowth more accessible.

Dans le 1er chapitre nous etudions l'action hamiltonien ne d'un goupe de lie g sur une variete de jacobi (m. Lambda ,e) en donnant des exemples d'actions admettant des applications moments coadjoints equivariants. Dans le 2eme chapitre, nous etudions l'action d'un groupe de lie g, connexe sur une variete bi-hamiltonienne (m,lambda ,lambda ). L'homomorphisme r : tm -> tm associe a la structure (m,lambda ,lambda ) est un operateur de recursion pour les systemes dynamiques dx/dt = x::(m)(x) ou x::(m) est un champ fondamental de l'action de g sur (m,lambda ,lambda ). Le dernier chapitre est consacre a l'etude des *-produits sur la variete bi-hamiltonienne (m,lambda ,lambda ). Apres avoir donne un theoreme d'existence, nous determinons un lien entre les *-produits d'un point sur (m,lambda ,lambda ), (m,lambda ) et d'autre part sur (m,lambda ) dans un cas particulier de structures bi-hamiltonienne que nous appelons c-tangentiellement exacte. Enfin nous considerons une variete de poisson reguliere tangentiellement exacte et nous donnons une condition d'existence de *-produits tangentiels invariants par l'action d'un groupe de lie

One of the most powerful aspects of conducting polymers is their ability to be nanostructured through innovative, synthetically manipulated, transformations, such as to tailor-make the polymers for specialized applications. In the exponentially increasing wide field of nanotechnology, some special attention is being paid to innovative hybrid dendrimer-core based polymeric smart materials. Star copolymers are a class of branched macromolecules having a central core with multiple linear polymer chains extending from the core. This intrinsic structural feature yields a unique 3D structure with extended conjugated linear polymer chains, resulting in star copolymers, which have higher ionic conductivities than their corresponding non-star conducting polymer counterparts. In this study an in-depth investigation was carried out into the preparation and characterization of specialized electronic &lsquo
smart materials&rsquo
. In particular, the preparation and characterization of novel conducting dendrimeric star copolymers which have a central poly(propylene imine) (PPI) dendrimer core with conducting polypyrrole (PPy) chains extending from the core was carried out. This involved, first, the preparation of a series of dendrimeric polypyrrole poly(propylene imine) star copolymers (PPI-co-PPy), using generations 1 to 4 (G1 to G4) PPI dendrimer precursors. The experimental approach involved the use of both chemical and electrochemical synthesis methods. The basic procedure involved a condensation reaction between the primary amine of a diamino functional PPI dendrimer surface and 2-pyrrole aldehyde, to afford the pyrrole functionalized PPI dendrimer (PPI-2Py). Polymerization of the intrinsically contained monomeric Py units situated within the dendrimer backbone was achieved via two distinctly different routes: the first involved chemical polymerization and the second was based on potentiodynamic oxidative electrochemical polymerization. The star copolymers were then characterized using various sophisticated analytical techniques, in-situ and ex-situ. Proton nuclear magnetic resonance spectroscopy (1HNMR) and Fourier transform infrared spectroscopy (FTIR) were used to determine the structures. Scanning electron microscopy (SEM) was used to determine the morphology. Themogravimetric analysis (TGA) was used to study the thermal stability of the prepared materials. X-ray diffraction analysis (XRD) was used to study the structural make-up of phases, crystallinity and amorphous content. Hall effect measurements were carried out to determine the electrical conductivity of the chemically prepared star copolymers. The PPI-co-PPy exhibited improved thermal stability compared to PPI-2Py, as confirmed by TGA. SEM results showed that the surface morphology of the functionalized dendrimer and star copolymer differed. The surface morphology of the chemically prepared star copolymers resembled that of a flaky, waxy material, compared to the ordered morphology of the electrochemically grown star copolymers, which resembled that of whelk-like helixes. In the case the electrochemically grown star copolymers, SEM images recorded at higher magnifications showed that the whelk-like helixes of the star copolymers were hollow tubes with openings at their tapered ends, and had an average base diameter of 2.0 &mu
m. X-ray diffraction analysis of the first generation star copolymer G1PPI-co-PPy revealed a broadly amorphous structure associated with PPy, and crystalline peaks for PPI. Cyclic voltammetry (CV), square wave voltammetry (SWV) and electrochemical impedance spectroscopy (EIS) techniques were used to study and model the electrochemical reactivity of the star copolymer materials. Electrochemical impedance spectroscopy data showed that the G1PPI-co-PPy exhibited slightly higher ionic conductivity than pristine PPy in lithium perchlorate. The second generation star copolymer G2PPI-co-PPy electrochemically deposited on a platinum (Pt) electrode had a lower electrochemical charge transfer resistance compared to electrodeposited polypyrrole (PPy) on a Pt electrode, and bare Pt. The decrease in charge transfer resistance was attributed to an increase in the conjugation length of the polymer as a result of the linking of the highly conjugated PPy to the PPI dendrimer. Bode impedimetric analysis indicated that G2PPI-co-PPI was a semiconductor, with a maximum phase angle shift of 45.3°
at 100 MHz. The star copolymer exhibited a 2- electron electrochemistry and a surface coverage of 99%. Results of Hall effect measurements showed that the star copolymer is a semiconducting material, having a conductivity of 0.7 S cm-1, in comparison to the 1.5 S cm-1 of PPy. To the best of my knowledge, these new star copolymers have not been reported in the open literature. Their properties make them potentially applicable for use in biosensors.

This thesis draws the line of a rise and a fall, an ironic pattern whereby the English stage of the long eighteenth century, in its relation to Shakespeare in particular, first acquired powerful influence, and then, through the very effects of that power, lost it. It also shows what contemporary literary criticism might learn from the activities that constitute this arc of evolution. My first chapter interrogates the relationship between text and performance in vernacular writings about acting and editing from the death of Betterton in 1710 to the rise of Garrick in the middle decades of the century. From the status of a distinct tradition, performance comes to rely on text as a basis for the intimate, personal engagement with Shakespeare believed necessary to the work of the sentimental actor. Such a reliance grants the performer new potential as a literary critic, but also prepares a fall. The performer becomes another kind of reader, and so is open to accusations of reading badly. My second chapter analyses the evolving definition of Shakespeare as a dramatic author from Samuel Johnson onwards. An untheatrical definition of the dramatic (Johnson's) is answered by one which recognises the power and vitality of the stage, especially in its representation of sympathetic character (Montagu and Kenrick). Yet that very recognition leads to a set of altered critical priorities in which the theatre is, once more, relegated (Morgann and Richardson). My third and fourth chapters consider the practices and critical implications of theatrical performance of Shakespeare during Garrick's career. I focus on the acting of emotion, the portrayal of what Aaron Hill called 'the very Instant of the changing Passion', and show that performance of this time, attentive to the striking moment and the transitions that power it, required from the actor both attention to the text and preternatural control over his own emotions. In return, it allowed Garrick and others to claim a special affinity with Shakespeare and to capture the public's attention, both in the theatre and outside it. Yet this situation, that of 'twin stars', does not last. French and German responses to English acting, the concern of my last chapter, show its decline particularly well. They also, however, show the power that existed in such a union between page and stage, and equal weight is given in both my third and my fourth chapter to how the theatrical-literary insights of eighteenth-century critical culture might also illuminate modern approaches.

The bulk of the stellar growth over cosmic time is dominated by IR-luminous galaxies at cosmic noon (z = 1-2), many of which harbor a hidden active galactic nucleus (AGN). We use state-of-the-art infrared color diagnostics, combining Spitzer and Herschel observations, to separate dust-obscured AGNs from dusty star-forming galaxies (SFGs) in the CANDELS and COSMOS surveys. We calculate 24 mu m counts of SFGs, AGN/star-forming "Composites," and AGNs. AGNs and Composites dominate the counts above 0.8 mJy at 24 mu m, and Composites form at least 25% of an IR sample even to faint detection limits. We develop methods to use the Mid-Infrared Instrument (MIRI) on JWST to identify dust-obscured AGNs and Composite galaxies from z similar to 1-2. With the sensitivity and spacing of MIRI filters, we will detect >4 times as many AGN hosts as with Spitzer/IRAC criteria. Any star formation rates based on the 7.7 mu m PAH feature (likely to be applied to MIRI photometry) must be corrected for the contribution of the AGN, or the star formation rate will be overestimated by similar to 35% for cases where the AGN provides half the IR luminosity and similar to 50% when the AGN accounts for 90% of the luminosity. Finally, we demonstrate that our MIRI color technique can select AGNs with an Eddington ratio of lambda(Edd) similar to 0.01 and will identify AGN hosts with a higher specific star formation rate than X-ray techniques alone. JWST/MIRI will enable critical steps forward in identifying and understanding dust-obscured AGNs and the link to their host galaxies.

This thesis examines an intermittent uncanniness that emerges in cultural responses to new image technologies, most recently in some impressions of the digital actor. The history of image technologies is punctuated by moments of fleeting strangeness: from Maxim Gorky's reading of the cinematographic image in terms of 'cursed grey shadows', to recent renderings of the computer-generated cast of Final Fantasy: The Spirits Within as silicon-skinned mannequins. It is not merely the image's unfamiliar and new aesthetics that render it uncanny. Rather, the image is received within a cultural framework where its perceived strangeness speaks allegorically of what it means to be human at that historical moment. In various ways Walter Benjamin, Anson Rabinbach and N. Katherine Hayles have claimed that the notion and the experience of 'being human' is continuously transformed through processes related to different stages of modernity including rational thought, industrialisation, urbanisation, media and technology. In elaborating this argument, each of the four chapters is organized around the elucidation of a particular motif: 'dummy', 'siren', 'doppelg??nger' and 'resurrection'. These motifs circulate through discourses on different categories of digital actor, from those conceived without physical referents to those that are created as digital likenesses of living or dead celebrities. These cultural responses suggest that even while writers on the digital actor are speculating about the future, they are engaging with ideas about life, death and identity that are very old and very ambivalent.

L’évolution des galaxies reste assez mal comprise. La densité de formation piquant entre 1
The evolution of galaxies is something that is still not well understood. The cosmic star formation rate density peaks between 1 < z < 3. It is therefore important to investigate the high-z Universe and the mechanisms which triggers or quenches star-formation in galaxies. In this thesis I investigate the effects of AGN feedback by studying high-z radio galaxies (HzRGs). For a sample of 25 HzRGs at 1 < z < 5.2, I add new ALMA data and determine the star formation rates (SFR) by multi-wavelength spectral energy distribution fitting. The ALMA data reveals that the mm continuum emission can be complicated, with contributions from several thermal dust emission components and/or synchrotron emission. The new estimated SFRs are 7 times lower than in previous studies. We might therefore be observing the effect of the AGN suppressing the growth of the host galaxy. For one source I explore the possibilities of constraining the gas Physics of the host galaxy and the halo gas by combining MUSE and ALMA data cubes. Quiescent ionized halo gas is detected, which coincide with a molecular gas reservoir detected with ALMA in [C I]. These observations probe the complex multi-phase halo gas and show the power of multi-wavelength observations

Supermassive black holes, black holes with masses <106 Msun, are found at the centers of all massive galaxies. These massive black holes grew from smaller seed black holes through accretion events. Accreting black holes are very bright in the radio through very hard X-ray spectral regimes. Due to the location of these accreting black holes at the centers of galaxies, they are referred to as active galactic nuclei (AGN). It is understood that AGN are an important phase of galaxy evolution; however, the role of AGN in massive galaxy formation is very poorly constrained. Here, the unique tool of multi-wavelength population synthesis modeling is used to study the average properties of AGN and their host galaxies with a focus on host galaxy star formation and the role of black hole growth in galaxy evolution. Knowledge of the AGN population from deep X-ray surveys is combined with theoretical AGN spectral energy distributions to predict various observables of the AGN population in wavelength regions from the far infrared to very hard X-rays. Comparison of the model predictions to observations constrains the model input parameters and allows for the determination of average properties of the AGN population. Particular attention is paid to a special class of AGN known as Compton thick AGN. These AGN are deeply embedded in gas and dust such that the column density obscuring the line of sight to the central engine of the AGN exceeds 1/σT ~ 10²⁴ cm⁻², where σT is the Thomson cross-section of the electron---a column density comparable to that of the human chest. Theoretical and simulational evidence suggest that these Compton thick AGN may be recently triggered, rapidly accreting AGN, making them of special interest to researchers. I found that Compton thick AGN are likely to contribute ~20% of the peak of the cosmic X-ray background (XRB) at ~30 keV and demonstrated that a significant portion of Compton thick AGN may be accreting very rapidly. Moreover, Compton thick AGN do not appear to follow the orientation based unified model of AGN. According to the unified model, AGN exhibit a range of obscuration levels due to a dusty 'torus' which, depending on the orientation of the torus to the observer's line of sight, may obscure the central engine of the AGN. Upon further investigation into the stellar populations of AGN host galaxies, it appears that the unified model holds in general at z < 1, but not at z > 1. I found that this is likely due to the dominant triggering mechanism of AGN switching from major mergers at z > 1.5 to secular processes by z ~ 1.

La phase initiale (de quelque fractions de seconde à quelques minutes) de la polymérisation catalytique des oléfines est encore peu comprise. Elle est pourtant reconnue comme une étape cruciale pour contrôler la morphologie de la particule de polymère et pour garantir la performance optimale du catalyseur et une certaine stabilité thermique du procédé. Ce travail présente l'étude et l'optimisation d'un mini réacteur à lit fixe pour mener des polymérisations catalytiques en phase gaz avec des durées très faibles (minimum 0.1s) dans des conditions proches à celles utilisées industriellement. La possibilité de suivre la température du gaz et de récupérer les particules de polymère pour les caractériser permet de décrire d'une façon complète le comportement du catalyseur au début de la réaction. L'étude a été limitée à la polymérisation de l'éthylène (avec un catalyseur métallocène supporté sur silice) et l'attention a été particulièrement mise sur la relation entre transfert de chaleur de la particule et performance du catalyseur. Il a été montré que des températures trop élevées peuvent être responsable localement de la modification du comportement du site active et de l'altération des propriétés des polymères. Un choix adéquat des conditions de réaction permet de suivre indirectement l'évolution de la température des particules en mesurant celle de la phase gaz. Dans un deuxième temps différents métallocènes ont été utilisés pour étudier l'influence des conditions de réaction, de la préparation du catalyseur et des propriétés du support sur l'activité, les propriétés du polymère et la morphologie des particules au temps court. Une attention particulière a été portée sur l'évolution des sites actifs et sur la cristallisation des chaînes de polymère dans un support poreux en évolution. Une activité élevée a été mesurée dans les premières cinq secondes et les températures de fusion et cristallisation des polymères ont été utilisées comme sondes pour mesurer l'avancement de la fragmentation du support. Les résultats ainsi obtenus peuvent non seulement clarifier certains aspects clé du début de la polymérisation mais aussi être utilisés comme donnés de départ pour modéliser la particule en croissance et contribuer à réduire l'écart qui est actuellement présent entre comportement réel du catalyseur et prédictions des modèles
The early stages (from less than 1s to few minutes) of catalytic olefin polymerization are still fairly understood even if they are nowadays recognized to be crucial for the determination of the morphology of the polymer particle, the optimization of the whole catalyst performance and the thermal stability of the process. In this work we will present how we studied and optimized a specially conceived packed bed reactor to perform gas phase catalytic olefin polymerizations as short as 0.1s under industrially relevant conditions. The possibility to measure the reactor temperature and to recover unaltered the polymer particles allows to take a complete picture of the catalyst behavior at the reaction start-up. The study will be restrained to ethylene polymerization with silica supported metallocenes and special attention will be given to the relation between heat transfer from the growing particle and catalyst performance. It will be seen how particle temperature evolution can be followed indirectly by measuring the gas phase temperature .In the second part of this work different metallocene complexes will be used to study the influence of process conditions, catalyst preparation method and support properties on the evolution of reaction rate, and polymer MWD during the first reaction seconds. Special attention will be given to the active site evolution during the transient phase and it will be shown that temperature excursions can be responsible for a local variation in active site behavior thus altering the properties of the formed polymer. The last section will be dedicated to the study of the peculiar crystallization behavior of the polymer chains in an evolving inorganic support. It will be shown how the melting and crystallization temperatures of the polymers can be used as “sensors” to measure the degree of fragmentation of the support particle. The results obtained in this work allow to gain a deeper understanding of the key parameters for the polymerization start-up and can be used as input for single particle models thus allowing to reduce the gap actually present between real catalyst behavior and model predictions

The bi-directional dc/dc converter is a very popular and effective tool for alternative energy applications. One way it can be utilized is to charge and discharge batteries used in residential solar energy systems. In the day, excess power from the PV panels is used to charge the batteries. During the night, the charged batteries will power the dc bus for loads in the house such as home appliances. The dual active bridge (DAB) converter is very useful because of its high power capability and efficiency. Its symmetry is effective in transferring power in both directions. However, the DAB converter has drawbacks in the start-up stage. These drawbacks in boost mode include high in-rush current during start-up, and the fact that the high side voltage cannot be lower than the low side voltage. A popular existing method to alleviate this problem is the use of an active clamp and a flyback transformer in the circuit topology to charge the high side before the converter is switched into normal boost operation. The active clamp not only helps eliminate the transient spike caused by the transformer leakage, but also continues to be used during steady state. However, this method introduces a new current spike occurring when the converter transitions from start-up mode to boost mode. To alleviate this new setback, an additional transitional stage is proposed to significantly reduce the current spike without the use of any additional components. The converter is current-fed on the low side, and voltage-fed on the high side. A simple phase shift control is used in buck mode and PWM control is used during the boost mode for both the start-up mode and the normal boost operation. This thesis discusses the performance results of a 48-400 V dc/dc converter with 1000 W power output.
Master of Science

The present quasi-naturalistic study used socio-cultural theory (Wertsch, 1998), picture theory (Mitchell, 1994) and the use of historical agency as a second-order concept (Lee & Ashby, 2000; Seixas & Morton, 2013) as a way of examining the historical thinking of high school seniors as they investigated second-wave feminism. Existing literature reflects the ways in which students understand historical agency (Barton, 1997; Winter, 2001; Peck, Poyntz, & Seixas, 2011), but has yet to examine its use as a conceptual tool to dissect controversial issues in history, such as feminism. The main research question was: in what ways do high school seniors employ historical agency as an analytical lens in examining second wave feminism? Supporting research questions included: (1) In what ways do high school seniors make sense of historical agency as a tool for taking informed action? (2) How do high school seniors use historical context to evaluate individual, collective or institutional choices and their consequences? (3) How do high school seniors define gender and feminism in the context of examining the struggle for women’s political, social and/or economic equality? Data included students’ responses to a questionnaire, notes and audio-recording transcripts from a historical thinking exercise that used historic photographs, and audio-recordings and transcripts of semi-structured interviews. Results indicated that participants understand the complexities surrounding historical agency including an actor’s choice and their challenges. Participants were also able to use historical agency as a conceptual tool to investigate gender, controversial issues, and change over time. Still, participants struggled with historical context and causation and relied heavily upon a narrative of progress. Further consideration of students’ use of historical agency might offer new insight into supporting a more inclusive history curriculum that highlights historical agency and women’s history in more authentic ways.

An important question in extragalactic astronomy concerns the distribution of black hole accretion rates of active galactic nuclei (AGNs). Based on observations at X-ray wavelengths, the observed Eddington ratio distribution appears as a power law, while optical studies have often yielded a lognormal distribution. There is increasing evidence that these observed discrepancies may be due to contamination by star formation and other selection effects. Using a sample of galaxies from the Sloan Digital Sky Survey Data Release 7, we test whether or not an intrinsic Eddington ratio distribution that takes the form of a Schechter function is consistent with previous work suggesting that young galaxies in optical surveys have an observed lognormal Eddington ratio distribution. We simulate the optical emission line properties of a population of galaxies and AGNs using a broad, instantaneous luminosity distribution described by a Schechter function near the Eddington limit. This simulated AGN population is then compared to observed galaxies via their positions on an emission line excitation diagram and Eddington ratio distributions. We present an improved method for extracting the AGN distribution using BPT diagnostics that allows us to probe over one order of magnitude lower in Eddington ratio, counteracting the effects of dilution by star formation. We conclude that for optically selected AGNs in young galaxies, the intrinsic Eddington ratio distribution is consistent with a possibly universal, broad power law with an exponential cutoff, as this distribution is observed in old, optically selected galaxies and X-rays.

Studies of central black holes (BHs) in nearby galaxies revealed tight correlation between the BH mass the host galaxy bulge mass, indicating a link between BH and star formation (SF) in the host galaxy. Luminous active galactic nuclei (AGN) are powered by mass accretion onto supermassive BHs. Observations of the AGNs and the SF in their host galaxies are required to understand their relation and how they establish this BH mass-galaxy bulge mass correlation over a wide range of cosmic lookback times. This thesis presents a survey of 24 μm-selected luminous AGN and their host galaxies up to z ~ 3.2. It focuses on the foreground and background broad line (Type-1) and narrow line (Type-2) AGNs of 30 massive galaxy cluster fields with total survey area of 5.2 deg², using the multi-wavelength dataset from the ultraviolet (UV) to far infrared (FIR) from the Local Cluster Substructure Survey. The AGN sample is nearly complete to a 1 mJy flux cutoff at 24 μm, and is optical-spectroscopically identified. With this dataset and the accompanying MMT/Hectospec spectroscopy survey, the properties of AGNs such as BH masses, BH accretion rates, and total luminosities, can be readily determined. Particularly, the Herschel data (100, 160, 250, 350, and 500 μm) sample the FIR peak of sources in our sample, and provide constraints on the star formation rates (SFR) in the host galaxies. For the Type 1 AGN sample, most of the systems are at z > 0.6 with luminosities > 10^45 ergs/s. Out of the 205 Type-1 AGNs, 107 are detected in at least two Herschel bands. We use AGN, stellar, and SF galaxy templates to decompose their spectral energy distributions (SEDs) from the UV to the FIR, and estimate their IR SF luminosities, AGN luminosities, and their host galaxy stellar masses. The SED decomposition reveals that a high level of SF is ubiquitous for our 24 μm-selected Type-1 AGN sample. For sources at z < 1, the stellar components from SED decomposition provide direct constraints on the stellar mass. For sources at z > 1, the BH mass-bulge stellar mass correlation is used for indirect constraints on the stellar mass. We carried out a similar analysis on the 85 Type-2 AGNs and their host galaxies up to z ~ 0.8, out of which 55 are detected in at least two Herschel bands. We reach the same conclusion as for the Type 1 AGN sample. That is, 1) These AGN host galaxies are very massive, and the vast majority of these galaxies have specific star formation rates (SSFR) consistent with those of main-sequence, star-forming galaxies rather than starbursting galaxies; 2) Most of these AGNs accrete at a rate close to 10% of Eddington; 3) We also find a strong correlation between the IR luminosity of the SF component and the AGN total luminosity, for both Type 1 and Type 2 AGNs. However, we show that the correlation could arise just because the BH mass (and hence AGN total luminosity) and the SF are both correlated with the galaxy mass, rather than requiring a causal connection between the observed rates of SF and the nuclear activity.

Seven very luminous galaxies were examined to determine the contribution of active nuclei to their luminosity, the nature of their stellar population, and the validity of previous measurements of their H₂ content. Spectra of the 2.3 μm bands of CO were used to measure the stellar velocity dispersion, and hence the mass in the central regions. The bolometric luminosity, ionizing continuum luminosity, CO index, and 2.2 μm luminosity were also determined. Models of young stellar populations were compared to the observed properties of the galaxies. It was found that four of the seven galaxies have properties which are inconsistent with those of stellar populations. The active nuclei of these four galaxies produce more than half the total light of the galaxies, but less than one-third of the 2.2 μm light. The galaxies containing AGN also have young stellar populations. There is no evidence for the existence of active nuclei in the other three galaxies. The stellar populations that dominate the starlight in the galaxies have a wide range of properties. Stellar populations range in age from 10 to 65 Myr. The timescale for star formation ranges from 5 Myr to 100 Myr. The local initial mass function is ruled out for one of the four galaxies for which stellar population analysis could be done. The molecular gas masses for some very luminous galaxies determined from the ¹²CO J = 1 → 0 line are in error. The previously determined molecular gas masses are larger than the dynamical masses. The I(CO)/M(H₂) conversion factor found for Milky Way giant molecular clouds is evidently not correct for some very luminous infrared galaxies.

Thesis (Ph.D.)--Indiana University, Dept. of Instructional Systems Technology, 2007.
Source: Dissertation Abstracts International, Volume: 68-09, Section: A, page: 3811. Adviser: Thomas M. Duffy. Title from dissertation home page (viewed May 8, 2008).

Background: Although clinicians encounter antimycobacterial treatment in Human mmunodeficiency (HIV)-infected children as one of the most common treatments coadministered with antiretroviral treatment (ART), quantitative data on the extent of antimycobacterial treatment among HIV-infected children at the time of commencement of ART and at different times during ART is scarce. The baseline risk factors associated with being on both ART and antimycobacterial treatments are not known and it remains to be elucidated how the different exposure factors impact on the antimycobacterial treatment-free survival of children who begin ART without antimycobacterial treatment.Objectives: To describe the prevalence of antimycobacterial treatment among children at the time of starting ART and the antimycobacterial treatment-free survival after starting ART. Design: A retrospective cohort study based on record reviews at the Harriet Shezi children&lsquo
s clinic (HSCC).Population: HIV-infected children less than fifteen years of age presumed ART naï
ve started on ART at HSCC.Analysis: A descriptive analysis of the prevalence of antimycobacterial treatment at time of start of ART was done. Kaplan Meier (KM) survival curves were used to determine the antimycobacterial treatment-free survival and logistic regression was used to analyze the association between baseline factors and future antimycobacterial treatment among children who had no antimycobacterial treatment at time of start of ART. Results: The prevalence of antimycobacterial treatment at the time of starting ART was 518/1941 (26.7%, 95% confidence interval (CI): 24.7-28.7). Among children who started ART without antimycobacterial treatment, the KM cumulative probability of antiretroviral and antimycobacterial (ART/antimycobacterial) co-treatment in the first 3 months of starting ART was 4.6% (95% CI: 4.1- 5.2), in the first 12 months it was 18.1% (95% CI: 17.0-19.2) and in the first 24 months of starting ART it was 24% (95% CI: 21.9-25.1). Survival analysis suggested that children with high baseline viral load, advanced World Health Organization (WHO) stage of disease, very low normalized weight for age (waz) and very young age (less than one year) at start of ART had significantly reduced antimycobacterial treatment-free survival (log rank p <
0.05) in the first two years of starting ART. In the logistic regression model, age less than one year {Odds ratio (OR): 3.7 (95% CI: 2.2-6.0
p <
0.0001)} and very low weight for age Z-score (waz <
-3) {OR
2.2 (95% CI: 1.4-3.6
p = 0.0015)} were the two critical risk factors independently associated with future antimycobacterial treatment. Conclusions: Antimycobacterial treatment is extremely common among HIV-infected children at the time of starting ART and early after starting ART and the incremental risk of being on ART/antimycobacterial co-treatment decreases with time on ART. The results emphasize the need for a heightened and careful alertness for mycobacterial events especially among children starting ART with severe malnutrition and those who start ART at age less than one year. The results further suggest that it is probably optimal to start ART in children before their nutritional status has deteriorated severely in the course of the HIV disease so that they get protection against mycobacterial events by early ART.

L’élaboration de prophéties autoréalisatrices est fréquente dans le domaine sportif. L’objet de la thèse est de mesurer leurs impacts sur des prises décision en situation motrice tout en vérifiant la persistance dans le temps de cet impact. Cette production est l’une des premières à tester l’effet des attentes par l’action motrice. Pour cela, nous procédons à une recherche quasi-expérimentale menée auprès de 285 étudiants en STAPS (Sciences & Techniques des Activités Physiques et Sportives) volontaires. Ces derniers sont soumis à un jeu de type Faucon versus Colombe révélant des conduites motrices rationnelles ou risquées. L’expérience consiste à donner à chaque sujet des attentes positives, neutres négatives avant d’analyser leurs stratégies et le score correspondant. Une Analyse Factorielle des Correspondances (AFC) renforcée régressions logistiques (Tri2) tend à montrer que les attentes positives sont significativement liées à des stratégies motrices antagonistes et à un score moyen (p<0.01). A contrario, les interactions de coopération associées à score élevé émanent plutôt des attentes négatives (p<0.01). L’absence d’attentes (indifférence) entraîne les sportifs dans une spirale de l’échec alors que des attentes négatives tendent à favoriser une phase d’observation prudente – type Tit for Tat – traduisant une forme d’intelligence motrice. Positives négatives, l’effet des attentes est donc bien réel et il en va du rôle de l’entraîneur que d’apprendre à les manier
No abstract

We present; 0 4 resolution extinction-independent distributions of star formation and dust in 11 star-forming galaxies (SFGs) at z. =. 1.3-3.0. These galaxies are selected from sensitive blank-field surveys of the 2 x 2' Hubble Ultra-Deep Field at gimel = 5 cm and 1.3 mm using the Karl G. Jansky Very Large Array and Atacama Large Millimeter/submillimeter Array. They have star formation rates (SFRs), stellar masses, and dust properties representative of massive main-sequence SFGs at z similar to 2. Morphological classification performed on spatially resolved stellar mass maps indicates a mixture of disk and morphologically disturbed systems; half of the sample harbor X-ray active galactic nuclei (AGNs), thereby representing a diversity of z similar to 2 SFGs undergoing vigorous mass assembly. We find that their intense star formation most frequently occurs at the location of stellar-mass concentration and extends over an area comparable to their stellar-mass distribution, with a median diameter of 4.2 similar to 1.8 kpc. This provides direct evidence of galaxy-wide star formation in distant blank-field-selected main-sequence SFGs. The typical galactic-average SFR surface density is 2.5Me circle dot yr(-1) kpc(-2), sufficiently high to drive outflows. In X-ray-selected AGN where radio emission is enhanced over the level associated with star formation, the radio excess pinpoints the AGNs, which are found to be cospatial with star formation. The median extinctionindependent size of main-sequence SFGs is two times larger than those of bright submillimeter galaxies, whose SFRs are 3-8 times larger, providing a constraint on the characteristic SFR (similar to 300Me yr(-1)) above which a significant population of more compact SFGs appears to emerge.

This investigation undertakes to re-centre the figure of the film star and their film appearances in the field of star study. To this end it uses Charlton Heston as its focus in a re-appraisal of existing methods of accounting for the star phenomenon in cinema. It also concomitantly re-assesses existing accounts of the significance of Charlton Heston as a film star. This thesis posits a robust method for identifying the specificities of the star’s contribution to a film’s meanings and effects across the body of their work by drawing on Andrew Britton’s understanding of the ‘star enactment’. Present approaches through which to engage with the details of a star’s performance are considered in detail and the weaknesses of those that seek to impose external schemas onto such discussions are highlighted. The difficulties with approaches that attempt to account for the star as a signifying phenomenon through the concepts of acting and performance are also considered. Existing methods which may allow for a fruitful investigation into the significance of the star enactment, such as the commutation test, are re- formulated in this study and their benefits are demonstrated through their application to key Heston star enactments. These new understandings are also made possible through the application of an ‘ekphrastic’ method of rendering film moments. Previous readings of Heston’s star figure are also re- appraised, and their conclusions questioned, through closer reference to the evidence of details from films. The fruitfulness of this method for analysing and commenting on film is thus demonstrated and Heston’s relationship to genre and its effect on performance style is also considered in order to be able to confidently assert the specific features of the Heston aesthetic.

Denna uppsats undersöker om högstadieelevers utsatthet för mobbning är en konsekvens av att de avviker från de normativa kategoriska tillhörigheterna, vilka definieras av den kulturellt idealiserade formen av maskulinitet respektive femininitet inom skolkontexten. Som teoretisk utgångspunkt används Messerschmidts structured action theory, som går ut på att individens handlingar och beteenden påverkas av och reproducerar den rådande sociala strukturen. I denna uppsats förstås den sociala strukturen som den ojämlika maktfördelningen mellan elever i skolkontexten, utifrån kön, klass och etnisk bakgrund. I vårt västerländska samhälle är det den vita heterosexuella medelklassmannen som besitter den största makten, och kallas för hegemonisk maskulinitet. Flickor kan nå upp till en normativ femininet som definieras utifrån liknande statusmarkörer. Elever som avviker från normen svensk, man och minst medelklassbakgrund besitter därför minst makt i skolkontexten, och har därmed en större risk att utsättas för mobbning än elever som når upp till hegemonisk maskulinitet och normativ femininitet i skolkontexten.Frågeställningarna i denna uppsats är om elever med få eller inga statusmarkörer har ett lägre självförtroende eller en sämre kamratanknytning, som ökar deras sannolikhet att utsättas för mobbning samt om Dan Olweus uppdelning av ”direkt” (fysisk) och ”indirekt” (psykosocial) mobbning är könsspecifika, men också har störst risk att drabba elever med få eller inga statusmarkörer. Få studier har forskat om dessa ”genusspecifika” former av mobbning även skiljer sig utifrån elevers kategoriska tillhörigheter. Forskare inom mobbningsfältet är vidare överens om att ett högt självförtroende och en stark kamratanknytning bör fungerar som ett vaccin mot mobbning. Dock har de använt sig av tvärsnittsdata som inte kan skönja tidsordningen för dessa samband.För att besvara dessa frågor har statistisk sekundärdata analyserats från ett urval av högstadieelever i Sverige, vilket har insamlats av Alkoholkommittén och Mobilisering mot narkotika. Datan har en longitudinell karaktär, vilket innebär att det går att besvara den första frågeställningen om tidsordningen i sambandet mellan självförtroende/ kamratanknytning och utsatthet för mobbning. I statistikprogrammet SPSS 16.0 används en binär logistisk regression för att analysera sambanden.Resultaten av dessa analyser har visat att elever med få eller inga statusmarkörer och med ett lågt självförtroende eller en svag kamratanknytning inte ökar deras sannolikhet att utsättas för mobbning. Dessutom visar resultaten att kön, klass och etnisk bakgrund inte påverkar risken för att utsättas för direkt eller indirekt mobbning. Omvänt säger resultaten att utsattheten för direkt och indirekt mobbning är könsneutrala, samt att ett högt självförtroende och en stark kamratanknytning inte fungerar som ett vaccin mot mobbning.

Laura Linney has an extensive education and experience in performance, which has influenced her to create a well-defined methodology when she approaches new roles. She uses a dialectical approach to performance. This approach has two parts as she outlined in a personal interview: phase one is her research, education, understanding of the script, and previous experiences working together to create a character, while phase two is her release of control over the character and the opportunity for the text (film or otherwise) and role to take on their own distinct personalities. This means that Linney eventually gives up agency over her characters in order for them to be effective and successful in the whole of a film. In effect, her characters are created by numerous influences within and outside her range of control. My intentions in this article are to prove that this dialectical methodology is prominent within all aspects of Laura Linney?s performances. In fact, I suggest that her utilization of this technique is what makes her a dynamic, effective, and unique actress. The dialectical nature of her performance techniques can be observed most effectively in specific breakthrough moments within her films. These moments exist most prominently in Linney?s films that are rooted in close character analysis like You Can Count On Me, The Savages, and the HBO mini-series John Adams. Close textual analyses of these scenes show a dramatic hiatus from the standard performance that she has used to help build a character. They show distinct differences between characters, which reinforces my point that each role is not only mandated by Linney?s creative power over her acting, but also a complete release of this control. They highlight how Linney allows herself to be directed and molded to develop deep, complex characters that work organically within the greater text of the film.

Robert Ryan (1909-1973) était de ces acteurs qui ne furent jamais starifiés. Pour autant, il ne resta pas non plus entièrement dans l’ombre de ses contemporains les plus reconnus. Rendu célèbre au cours de l’année 1947 par Crossfire (Feux croisés, Edward Dmytryk), il fut, depuis cette zone grise de la « non-starification », ce personnage de film noir à la fois névrosé et violent, tout aussi affirmatif que désorienté – mais pas uniquement. Aujourd’hui oublié comme la plupart des acteurs de cette catégorie, il apparut pourtant dans soixante-treize longs-métrages, parfois réalisés par des cinéastes de renoms tels que Jean Renoir, Nicholas Ray, Anthony Mann, Max Ophuls ou encore Fritz Lang, et sa carrière se prolongea au théâtre et à la télévision. En partant de quelques incarnations pour remonter vers ce qui faisait la singularité du jeu de Robert Ryan, puis en tentant d’inscrire l’acteur dans l’histoire esthétique du cinéma de son temps, le présent texte se penche sur l’un de ces Hollywood standby méconnus, qui firent pourtant office de matériaux essentiels aux films américains classiques
Robert Ryan (1909-1973) was one of those actors who never became a movie star. However, he was not completely in the shadow of his famous contemporaries. Celebrated for his part in Edward Dmytryk’s Crossfire (1947), he was this "non-star" actor playing neurotic, violent, affirmative and disorientated film noir characters, but he was not only that. If he has been forgotten today, like most actors of his kind, he nevertheless made seventy-three movies, sometimes directed by filmmakers such as Jean Renoir, Nicholas Ray, Anthony Mann, Max Ophuls or Fritz Lang, and he also had a career in theatre and television. Through the description of some of his roles, by analyzing the peculiarity of his acting style, and trying to place him within the aesthetic history of American cinema, the following text deals with one of those underrated "Hollywood standby", that were vital to the craft of American cinema

The purpose of this study was to report on the sustainability of school-based psycho-social support projects that have been initiated in a school in the Eastern Cape. More specifically, the study explored how insights into sustainable psycho-social support by teachers might inform knowledge on resilience in schools. The study forms part of the broad STAR (Supportive Teachers, Assets and Resilience) research project that has been ongoing since 2003. The current study utilised Interpretivism as metatheory and Participatory Reflection and Action (PRA) as methodological paradigm. A case study design was selected, with eight purposefully selected primary school teachers as participants, who have been involved in the STAR project since 2003. Two field visits were undertaken for data collection purposes. The participants took part in two PRA-based workshops, with the second workshop taking the form of a member checking session. In addition to the PRA-based workshops, I relied on observations, field notes, photographs, audio-recordings and a research diary as data collection and documentation strategies. Subsequent to thematic data analysis four main themes emerged. Firstly the importance of teamwork in sustaining psycho-social support initiatives was identified, with the various roles and responsibilities within the team, and school management acting as a silent partner emerging as sub-themes. Secondly, participants highlighted collaboration (with the University of Pretoria, community and other schools) as underlying reasons for sustaining support efforts. Thirdly, participants regarded acknowledgement by others as motivating factors, with reference to acknowledgement on multiple levels and acknowledgement resulting in self-confidence as sub-themes. Finally, participants focused on teacher identity as the determining factor for sustaining psycho-social support initiatives, referring to being in a caring profession, putting children first, being change agents in the community and being committed and dedicated. Based on the findings of the study, I can conclude that sustaining psycho-social support seemed to establish the school as a protective resource to promote resilience. The acknowledgement of teachers’ abilities and capabilities similarly had a positive effect on teachers’ identification and mobilisation of assets and resources in collaboration with community partners, which in turn positively impacted teachers’ confidence. Additional information available on a CD stored at the Merensky Library on Level 3
Dissertation (MEd)--University of Pretoria, 2010.
Educational Psychology
unrestricted

Practitioners of Forecast-based Action (FbA) argue that a humanitarian response able to utilize forecasts to accurately predict disaster, secure funding, and take action before the onset of a crisis will benefit donors and beneficiaries alike. In search of effective and efficient early-action regimes, a number of major humanitarian actors are developing FbA projects of various designs, predominantly in response to natural disaster and famine. While numerous organizations and institutions have expressed interest in developing FbA mechanisms, the tool has only been applied in a limited capacity to the humanitarian needs generated by armed conflict. This research seeks to understand whether a scalable FbA approach can be developed to stage principled, anticipatory humanitarian action in response to situations in which rigorous evaluations predict the likelihood of imminent armed conflict. The hypothesis is that the application of FbA to armed conflict is possible, but due to the complex political nature of conflict, implementing organizations should try to focus on creating mechanisms managed by humanitarian actors and, in so far as possible, be insulated from outside influence. This research is the first academic work to specifically investigate the application of FbA to armed conflict. Following an extensive review of current FbA mechanisms and conflict early warning practices, this research concludes that a conflict-centered FbA system akin to the automated FbA systems in use today to respond to natural disaster and famine is possible, but that the endeavor presents many practical and conceptual barriers to implementation. In particular, diffuse models such as the Start Fund offer a hopeful glimpse at a type of horizontal, member-driven FbA mechanism that is both highly context-sensitive and relatively insulated from outside influence. Such a design, however, features notable and inherent limitations in its ability to reliably and accurately predict the outbreak of conflict and respond in a manner that minimizes regretful actions.

Satisfying a campaign pledge to the National Education Association (NEA), President Jimmy Carter pushed for a federal Department of Education in 1978 and 1979. In the ensuing legislative battle, Carter confronted opposition from states’ rights, social, and religious conservatives that were beginning to form the nucleus of the New Right in the Republican Party. Using divisive racial and religious issues, these conservatives tried, and failed, to thwart the Department of Education project. Congressional testimony, the Carter administration’s internal documents, and newspaper editorials illustrate that the Department of Education battle foreshadowed the Reagan Revolution of 1980.

Les trous noirs supermassifs résident dans les centres de la plupart des galaxies massives et on observe des corrélations entre leurs masses et les propriétés de leurs galaxies hôtes. De plus, on observe des trous noirs de plus d’un milliard de masses solaires quelques centaines de millions d’années seulement après le Big Bang. Ces trous noirs supermassifs présents dans l’univers jeune ne sont que le sommet de l’iceberg de l’ensemble de la population de trous noirs, mais ils mettent en question notre compréhension de la formation et de la croissance des premiers trous noirs. Notre nouvelle méthode améliorant le calcul de la densité de colonne de H2 donne des probabilités pour former des graines massives de trous noirs qui sont plus d’un ordre de grandeur plus élevées que prédit précédemment. Nous trouvons que CR7 pourrait être le premier candidat à héberger un tel trou noir formé par effondrement direct et nous démentons l’existence initialement revendiquée d’une population stellaire massive primordial dans CR7. Nous calculons la densité des taux de fusion des trous noirs binaires des premières étoiles et leurs taux de détection avec aLIGO. Notre modèle démontre que les détections des ondes gravitationnelles à venir au cours des prochaines décennies permettront d’imposer des contraintes plus strictes sur les propriétés des premières étoiles et donc sur les scénarios de formation des premiers trous noirs. Nous développons un modèle analytique en 2D de la rétroaction des noyaux actifs de galaxie pour démontrer qu’un profil de disque plus réaliste réduit la quantité de gaz qui est éjectée du halo par rapport aux modèles 1D existants. La rétroaction empêche l’accretion de gaz sur le trou noir central pendant seulement ∼1 million d’année environ, ce qui permet une accretion de gaz presque continue dans le plan du disque. Avec cette thèse, je contribue à une meilleure compréhension de la formation et la croissance des premiers trous noirs supermassifs
Supermassive black holes reside in the centres of most massive galaxies and we observe correlations between their mass and properties of the host galaxies. Besides this correlation between a galaxy and its central black hole (BH), we see BHs more massive than one billion solar masses already a few hundred million years after the Big Bang. These supermassive BHs at high redshift are just the tip of the iceberg of the entire BH population, but they challenge our understanding of the formation and growth of the first BHs. Our improved method to calculate H2 self-shielding yields probabilities to form massive seed BHs that are more than one order of magnitude higher, than previously expected. We find that CR7 might be the first candidate to host such a direct collapse BH and we disprove the initially claimed existence of a massive metal-free stellar population in CR7. We calculate the merger rate density of binary BHs from the first stars and their detection rates with aLIGO. Our model demonstrates that upcoming detections of gravitational waves in the next decades will allow to put tighter constraints on the properties of the first stars and therefore on formation scenarios of the first BHs. We develop a 2D analytical model of active galactic nuclei-driven outflows to demonstrate that a more realistic disc profile reduces the amount of gas that is ejected out of the halo, compared to existing 1D models. The outflow prevents gas accretion on to the central BH for only about ∼1Myr, which permits almost continuous gas inflow in the disc plane. With this thesis, I contribute to a better understanding of the formation and growth of the first supermassive BHs

We present a detailed, multi-wavelength study of star formation (SF) and active galactic nucleus (AGN) activity in 11 near-infrared (IR) selected, spectroscopically confirmed massive (greater than or similar to 10(14)M(circle dot)) galaxy clusters at 1 < z < 1.75. Using new deep Herschel/PACS imaging, we characterize the optical to far-IR spectral energy distributions (SEDs) for IR-luminous cluster galaxies, finding that they can, on average, be well described by field galaxy templates. Identification and decomposition of AGNs through SED fittings allows us to include the contribution to cluster SF from AGN host galaxies. We quantify the star-forming fraction, dust-obscured SF rates (SFRs) and specific SFRs for cluster galaxies as a function of cluster-centric radius and redshift. In good agreement with previous studies, we find that SF in cluster galaxies at z greater than or similar to 1.4 is largely consistent with field galaxies at similar epochs, indicating an era before significant quenching in the cluster cores (r < 0.5 Mpc). This is followed by a transition to lower SF activity as environmental quenching dominates by z similar to 1. Enhanced SFRs are found in lower mass (10.1< logM(kappa)/M-circle dot < 10.8) cluster galaxies. We find significant variation in SF from cluster to cluster within our uniformly selected sample, indicating that caution should be taken when evaluating individual clusters. We examine AGNs in clusters from z = 0.5-2, finding an excess AGN fraction at z greater than or similar to 1, suggesting environmental triggering of AGNs during this epoch. We argue that our results-a transition from field-like to quenched SF, enhanced SF in lower mass galaxies in the cluster cores, and excess AGNs-are consistent with a co-evolution between SF and AGNs in clusters and an increased merger rate in massive halos at high redshift.

In industrialized economies such as the European countries unemployment rates are very responsive to the business cycle and significant shares stay unemployed for more than one year. To fight cyclical and long-term unemployment countries spend significant shares of their budget on Active Labor Market Policies (ALMP). To improve the allocation and design of ALMP it is essential for policy makers to have reliable evidence on the effectiveness of such programs available. Although the number of studies has been increased during the last decades, policy makers still lack evidence on innovative programs and for specific subgroups of the labor market. Using Germany as a case study, the dissertation aims at contributing in this way by providing new evidence on start-up subsidies, marginal employment and programs for youth unemployed. The idea behind start-up subsidies is to encourage unemployed individuals to exit unemployment by starting their own business. Those programs have compared to traditional programs of ALMP the advantage that not only the participant escapes unemployment but also might generate additional jobs for other individuals. Considering two distinct start-up subsidy programs, the dissertation adds three substantial aspects to the literature: First, the programs are effective in improving the employment and income situation of participants compared to non-participants in the long-run. Second, the analysis on effect heterogeneity reveals that the programs are particularly effective for disadvantaged groups in the labor market like low educated or low qualified individuals, and in regions with unfavorable economic conditions. Third, the analysis considers the effectiveness of start-up programs for women. Due to higher preferences for flexible working hours and limited part-time jobs, unemployed women often face more difficulties to integrate in dependent employment. It can be shown that start-up subsidy programs are very promising as unemployed women become self-employed which gives them more flexibility to reconcile work and family. Overall, the results suggest that the promotion of self-employment among the unemployed is a sensible strategy to fight unemployment by abolishing labor market barriers for disadvantaged groups and sustainably integrating those into the labor market. The next chapter of the dissertation considers the impact of marginal employment on labor market outcomes of the unemployed. Unemployed individuals in Germany are allowed to earn additional income during unemployment without suffering a reduction in their unemployment benefits. Those additional earnings are usually earned by taking up so-called marginal employment that is employment below a certain income level subject to reduced payroll taxes (also known as “mini-job”). The dissertation provides an empirical evaluation of the impact of marginal employment on unemployment duration and subsequent job quality. The results suggest that being marginal employed during unemployment has no significant effect on unemployment duration but extends employment duration. Moreover, it can be shown that taking up marginal employment is particularly effective for long-term unemployed, leading to higher job-finding probabilities and stronger job stability. It seems that mini-jobs can be an effective instrument to help long-term unemployed individuals to find (stable) jobs which is particularly interesting given the persistently high shares of long-term unemployed in European countries. Finally, the dissertation provides an empirical evaluation of the effectiveness of ALMP programs to improve labor market prospects of unemployed youth. Youth are generally considered a population at risk as they have lower search skills and little work experience compared to adults. This results in above-average turnover rates between jobs and unemployment for youth which is particularly sensitive to economic fluctuations. Therefore, countries spend significant resources on ALMP programs to fight youth unemployment. However, so far only little is known about the effectiveness of ALMP for unemployed youth and with respect to Germany no comprehensive quantitative analysis exists at all. Considering seven different ALMP programs, the results show an overall positive picture with respect to post-treatment employment probabilities for all measures under scrutiny except for job creation schemes. With respect to effect heterogeneity, it can be shown that almost all programs particularly improve the labor market prospects of youths with high levels of pretreatment schooling. Furthermore, youths who are assigned to the most successful employment measures have much better characteristics in terms of their pre-treatment employment chances compared to non-participants. Therefore, the program assignment process seems to favor individuals for whom the measures are most beneficial, indicating a lack of ALMP alternatives that could benefit low-educated youths.
Zur Verbesserung der Arbeitsmarktchancen arbeitsloser Personen und damit zur Bekämpfung von Arbeitslosigkeit werden innerhalb der Europäischen Union jedes Jahr beträchtliche Summen für Maßnahmen der aktiven Arbeitsmarktpolitik (AAP) aufgewendet. Vor diesem Hintergrund ergibt sich die Frage nach der Effektivität dieser Programme. Obwohl in den vergangenen Jahren zahlreiche empirische Evaluationsstudien durchgeführt und hierdurch wesentliche Erkenntnisse über die Wirksamkeit von AAP gewonnen wurden, bestehen noch stets unerforschte bzw. nur unzureichend erforschte Bereiche, wie zum Beispiel für innovative Programme oder für Untergruppen am Arbeitsmarkt. Hierin liegt der Beitrag der Dissertationsschrift. Am Beispiel von Deutschland werden neue Erkenntnisse zur Wirksamkeit der Existenzgründungsförderung, der geringfügigen Beschäftigung sowie der Programme für arbeitslose Jugendliche geliefert. Mit Einführung des Existenzgründungszuschusses (Ich-AG) im Rahmen der Hartz-Reformen, standen gründungswilligen Arbeitslosen, zusammen mit dem bereits seit Mitte der Achtziger Jahre bekannten Überbrückungsgeld, zwischen 2003 und 2006 zwei Förderprogramme zur Verfügung. Beide Programme umfassen eine monetäre Förderung während der Gründungsphase, um arbeitslosen Personen den Weg in die berufliche Selbständigkeit zu erleichtern. Die Analyse der beiden Programme zeigt deutlich, dass die intendierten Ziele, d.h. die Verbesserung der Beschäftigungschancen sowie der Einkommenssituation der Teilnehmer, erreicht wurden. Es zeigt sich weiter, dass beide Programme insbesondere effektiv für benachteiligte Gruppen am Arbeitsmarkt, wie z.B. Geringqualifizierte, sowie in Regionen mit eher schlechten ökonomischen Bedingungen sind. Aber auch die getrennte Analyse für Frauen zieht eine positive Bilanz. Hier erweist sich die Förderung als besonders wirksam, da die berufliche Selbständigkeit (im Gegensatz zur abh. Beschäftigung) anscheinend eine bessere Vereinbarkeit von Familie und Beruf ermöglicht. Abschließend lässt sich somit feststellen, dass die Förderung der beruflichen Selbständigkeit eine sinnvolle Strategie darstellt, da insbesondere bestehende Hürden für benachteiligte Gruppen am Arbeitsmarkt beseitigt und diese Personen langfristig in den Arbeitsmarkt integriert werden. Im nächsten Abschnitt der Dissertationsschrift wird die Aufnahme einer geringfügigen Beschäftigung während der Arbeitslosigkeit untersucht. In Deutschland können arbeitslose Personen bis zu 15 Stunden/Woche eine Beschäftigung aufnehmen, wobei ein Zuverdienst bis 165 Euro/Monat keine Auswirkung auf den Bezug von Arbeitslosengeld hat. Hierzu greifen arbeitslose Personen insbesondere auf die geringfügige Beschäftigung (genannt „Mini-Job“) zurück, da diese für die Arbeitslosen selbst abgabenfrei ist und Arbeitgeber nur einen reduzierten Beitrag zur Sozialversicherung sowie Einkommensteuer zahlen. Das erhöhte Einkommensniveau während der Arbeitslosigkeit sowie der enge Kontakt zum Arbeitsmarkt können unterschiedliche Wirkungen generieren. Es zeigt sich, dass die Aufnahme einer geringfügigen Beschäftigung grundsätzlich keinen signifikanten Einfluss auf die Arbeitslosigkeitsdauer hat, jedoch im Anschluss an die Arbeitslosigkeit zu längeren Beschäftigungsphasen führt. Die Untersuchung der Effektheterogenität zeigt, dass die geringfügige Beschäftigung während der Arbeitslosigkeit die Arbeitslosigkeitsdauer für Langzeitarbeitslose verkürzt und zu insgesamt stabileren Beschäftigungsphasen für diese Personengruppe führt. Das Ergebnis ist von hoher politischer Relevanz, da die Möglichkeit einer Zusatzbeschäftigung während der Arbeitslosigkeit anscheinend ein effektives Instrument zur Bekämpfung von Langzeitarbeitslosigkeit darstellt. Abschließend beschäftigt sich die Dissertationsschrift mit der Untersuchung der Effektivität von AAP zur Verbesserung der Arbeitsmarktchancen von arbeitslosen Jugendlichen. Jugendliche sind im Gegensatz zu Erwachsenen häufiger von Arbeitslosigkeit betroffen, da sie über geringere Such- bzw. Arbeitserfahrung verfügen. Die Bekämpfung von Jugendarbeitslosigkeit steht daher im Fokus der AAP. Vor diesem Hintergrund ist es erstaunlich, dass bisher nur wenig über die Wirksamkeit von AAP für arbeitslose Jugendliche bekannt ist bzw. für Deutschland hierzu noch überhaupt keine Erkenntnisse existieren. Die Dissertationsschrift liefert nun erstmalig Evidenz zur Wirksamkeit von AAP für arbeitslose Jugendliche in Deutschland. Die untersuchten Programme (außer Arbeitsbeschaffungsmaßnahmen) erhöhen die Beschäftigungswahrscheinlichkeit der Teilnehmer gegenüber den Nicht-Teilnehmern. Allerdings zeigt sich auch, dass arbeitslose Jugendliche ohne bzw. mit Hauptschulabschluss weniger von einer Programmteilnahme profitieren als Jugendliche mit einer höheren Schulbildung. Hier scheint noch Optimierungsbedarf zu bestehen, indem die Ausgestaltung der AAP stärker auf die Bedürfnisse von geringqualifizierten Jugendlichen eingehen sollte.

The two SCUBA HAlf-Degree Extragalactic Survey (SHADES) fields are amongst the richest places in the sky in terms of multi-wavelength coverage. They comprise an eastern section of the Lockman Hole (LH) and the central portion of the Subaru- XMM/Newton Deep Field (SXDF). In this thesis, I have obtained extremely deep, multi-frequency radio imaging of the SHADES fields using the GiantMetre-wave Radio Telescope (GMRT) and the Very Large Array (VLA), at 610MHz and 1.4GHz, respectively. These data are used to analyse the nature of the sub-milliJansky (sub-mJy) radio population, which has been hotly debated in the last few years: are they powered by star-forming or nuclear activity? To tackle the problem, I employ different approaches making use of the large variety of multi-wavelength data in the SHADES fields. I begin by analysing the spectral index, α610MHz 1.4GHz , of radio sources detected in the LH, to explore the dominant emission mechanism. Based on a robust 10 σ detection criterion, I find a constantmedian spectral index of α610MHz 1.4GHz ≈ −0.6 to −0.7 for sources between S1.4GHz ≈ 200 μJy and 10mJy. This result suggests that the galaxy population in the sub-mJy regime is powered by optically-thin synchrotron emission – starforming galaxies or lobe-dominated active galactic nuclei (AGN). Making use of X-ray observations in the LH, I show that the fraction of radio sources detected in the hard X-ray band (between 2 and 10 keV) decreases from 50 to 15 per cent between S1.4GHz ≈ 1mJy and . 100 μJy, which strongly suggests a transition from AGN to star-forming galaxies. Based on the deep, multi-wavelength coverage of the SXDF, I explore the behaviour of the far-infrared (FIR)/radio correlation as a function of redshift. I combine the q24 factor – the logarithmic flux density ratio between Spitzer 24-μm and VLA 1.4- GHz flux densities – with available photometric redshifts and find strong evidence that the correlation holds out to z ≈ 3.5. Based on M82-like k-corrections and using a high-significance (S1.4GHz > 300 μJy) radio sub-sample, I find a mean and scatter of q24 = 0.71 ± 0.47. Monte-Carlo simulations based on these findings show that fewer sources deviate from the correlation at fainter flux densities (i.e. fewer radioloud AGN). I predict that the radio-loud fraction drops from 50 per cent at ∼ 1mJy to zero at . 100 μJy. The validity of the FIR/radio correlation out to very high redshifts adds credibility to identifications of sub-millimetre (submm) galaxies (SMGs) made at radio wavelengths. Based on a sample of 45 radio-identified SMGs in the LH, I find a median radio spectral index of α610MHz 1.4GHz = −0.72 ± 0.07, which suggests that optically-thin synchrotron is the dominant radio emission mechanism. Finally, as anAppendix I include a theoretical treatment that constrains the average geometry of the dusty, torus-like structures believed to obscure a large fraction of the AGN population. I use the distribution of column densities (NH) obtained from deep ∼ 1Msec X-ray observations in the Chandra Deep Field South. I find that to reproduce the wide observed range of NH, the best torus model is given by a classical “donut”- shaped distribution with an exponential angular dependency of the density profile.

Les systèmes de recommandation visent à présélectionner et présenter en premier les informations susceptibles d'intéresser les utilisateurs. Ceci a suscité l'attention du commerce électronique, où l'historique des achats des utilisateurs sont analysés pour prédire leurs intérêts futurs et pouvoir personnaliser les offres ou produits (appelés aussi items) qui leur sont proposés. Dans ce cadre, les systèmes de recommandation exploitent les préférences des utilisateurs et les caractéristiques des produits et des utilisateurs pour prédire leurs préférences pour des futurs items. Bien qu'ils aient démontré leur précision, ces systèmes font toujours face à de grands défis tant pour le monde académique que pour l'industrie : ces techniques traitent un grand volume de données qui exige une parallélisation des traitements, les données peuvent être également très hétérogènes, et les systèmes de recommandation souffrent du démarrage à froid, situation dans laquelle le système n'a pas (ou pas assez) d'informations sur (les nouveaux) utilisateurs/items pour proposer des recommandations précises. La technique de factorisation matricielle a démontré une précision dans les prédictions et une simplicité de passage à l'échelle. Cependant, cette approche a deux inconvénients : la complexité d'intégrer des données hétérogènes externes (telles que les caractéristiques des items) et le démarrage à froid pour un nouvel utilisateur. Cette thèse a pour objectif de proposer un système offrant une précision dans les recommandations, un passage à l'échelle pour traiter des données volumineuses, et permettant d'intégrer des données variées sans remettre en question l'indépendance du système par rapport au domaine d'application. De plus, le système doit faire face au démarrage à froid utilisateurs car il est important de fidéliser et satisfaire les nouveaux utilisateurs. Cette thèse présente quatre contributions au domaine des systèmes de recommandation: (1) nous proposons une implémentation d'un algorithme de recommandation de factorisation matricielle parallélisable pour assurer un meilleur passage à l'échelle, (2) nous améliorons la précision des recommandations en prenant en compte l'intérêt implicite des utilisateurs dans les attributs des items, (3) nous proposons une représentation compacte des caractéristiques des utilisateurs/items basée sur les filtres de bloom permettant de réduire la quantité de mémoire utile, (4) nous faisons face au démarrage à froid d'un nouvel utilisateur en utilisant des techniques d'apprentissage actif. La phase d'expérimentation utilise le jeu de données MovieLens et la base de données IMDb publiquement disponibles, ce qui permet d'effectuer des comparaisons avec des techniques existantes dans l'état de l'art. Ces expérimentations ont démontré la précision et l'efficacité de nos approches
Recommender Systems aim at pre-selecting and presenting first the information in which users may be interested. This has raised the attention of the e-commerce, where the interests of users are analysed in order to predict future interests and to personalize the offers (a.k.a. items). Recommender systems exploit the current preferences of users and the features of items/users in order to predict their future preference in items.Although they demonstrate accuracy in many domains, these systems still face great challenges for both academia and industry: they require distributed techniques to deal with a huge volume of data, they aim to exploit very heterogeneous data, and they suffer from cold-start, situation in which the system has not (enough) information about (new) users/items to provide accurate recommendations. Among popular techniques, Matrix Factorization has demonstrated high accurate predictions and scalability to parallelize the analysis among multiple machines. However, it has two main drawbacks: (1) difficulty of integrating external heterogeneous data such as items' features, and (2) the cold-start issue. The objective of this thesis is to answer to many challenges in the field of recommender systems: (1) recommendation techniques deal with complex analysis and a huge volume of data; in order to alleviate the time consumption of analysis, these techniques need to parallelize the process among multiple machines, (2) collaborative filtering techniques do not naturally take into account the items' descriptions in the recommendation, although this information may help to perform more accurate recommendations, (3) users' and items' descriptions in very large dataset contexts can become large and memory-consuming; this makes data analysis more complex, and (4) the new user cold-start is particularly important to perform new users' recommendations and to assure new users fidelity. Our contributions to this area are given by four aspects: (1) we improve the distribution of a matrix factorization recommendation algorithm in order to achieve better scalability, (2) we enhance recommendations performed by matrix factorization by studying the implicit interest of the users in the attributes of the items, (3) we propose an accurate and low-space binary vector based on Bloom Filters for representing users/items through a high quantity of features in low memory-consumption, and (4) we cope with the new user cold-start in collaborative filtering by using active learning techniques. The experimentation phase uses the publicly available MovieLens dataset and IMDb database, what allows to perform fair comparisons to the state of the art. Our contributions demonstrate their performance in terms of accuracy and efficiency

Essa pesquisa se destina a discutir a crise de eficiência por qual passa o Poder Judiciário brasileiro, decorrente dos processos repetitivos, e as soluções processuais para buscar amenizá-la. Primeiramente far-se-á uma análise da situação atual dos tribunais nacionais, da carga de trabalho e dos efeitos da crise de eficiência na demora da prestação jurisdicional, bem como na sua influência maléfica nos direitos e garantias fundamentais ao acesso à justiça plena. Posteriormente, em busca de soluções, far-se-á uma análise comparada de instrumentos de agregação de demandas repetitivas dos Estados Unidos com os instrumentos correlatos do Brasil. Os institutos escolhidos para análise, diga-se, aqueles que se compreende serem os mais adequados no intento de solucionar as demandas repetitivas, subdividem-se em dois grupos: aqueles destinados a resolver processos oriundos da mesma questão de fato a coletivização e aqueles destinados a resolver processos envolvendo exclusivamente a mesma questão de direito vinculação de precedentes. Dessa maneira, de um lado estudar-se-á a class action, de modo a extrair dela os instrumentos necessários a fim de conferir aos institutos brasileiros de coletivização, particularmente à ação civil pública para tutela de direitos individuais homogêneos, maior eficiência para solução de conflitos repetitivos. Objetivando-se, sempre, imprimir eficácia, segurança jurídica e celeridade ao processo. De outro lado analisar-se-á o stare decisis, fazendo-se um paralelo com a jurisprudência vinculante e a experiência brasileira no manuseio da jurisprudência súmula vinculante, súmula persuasiva etc. A conclusão buscará encontrar na experiência dos institutos de agregação norteamericanos ensinamentos que possam contribuir de forma positiva com os institutos brasileiros de modo a conferir eficiência no manuseio das causas repetitivos, reduzindo, assim, o congestionamento do Poder Judiciário.
This research aims to discuss the efficiency crisis that affects the Judiciary Power in Brazil due to repetitive litigation and the procedural solutions thought to solve it. First of all, it will be analyzed the actual situation of Brazilian Courts: workloads delay in the jurisdictional answer, as well as the direct consequences of delay on the due process and right to one day in court. Secondly, in search of solutions, this research will do a compared analysis of the aggregation techniques for solving repetitive litigation in the United States and in Brazil. The techniques chosen for study, those that are thought to be the best ones in the aim of bringing efficiency to civil procedure, are subdivided into two groups: the ones destined to solving procedures born from the same transaction or occurrence preclusion mechanisms and secondly, the ones destined to solving procedures uniquely discussing the same question of law stare decisis. Therefore, the study shall be divided into three chapters: one for problematic, one for studding the class action and one for stare decisis. The class action will be compared with the Brazilian technique for solving mass tort cases (ação civil pública para tutela de interesses individuais homogêneos), suggesting modifications and improvements in the Brazilian legislation starting by the American class action study. Finally, stare decisis will be compared with the Brazilian experience with dealing with jurisprudence and mandatory case law. All of it in the aim of finding the best technique for solving repetitive litigation and improving the Brazilian procedural system, with efficiency and fairness

Active Galactic Nuclei (AGNs) are the most mystic objects in the universe. They are usually very far away from our Galaxy, which means that they are ancient objects. They are also luminous and have unique features in their spectra. Studying AGNs helps understanding the early universe and the evolution of galaxies. This Dissertation aims to research the structure of AGNs and the cooling function in the AGNs environment. I first investigate what optical/ultraviolet spectroscopic features would be produced by Broad-line Region (BLR) clouds crossing our line of sight to the accretion disk, the source of the optical/UV continuum. This research, prompted by recent X-ray observations, suggests that single cloud has little effect on the optical/UV spectrum. However, an ensemble of clouds produces a strong distinctive feature between the Lyman limit and Lyα. The extent of these features indicates the line-of-sight covering factor of clouds and may explain the ubiquitous AGN spectral break around 1100Å. I next study, considering the physical parameters of AGNs, how the gas cooling function changes at high temperature (T > 104 K) over a wide range of density (nH < 1012 cm−3) and metallicity (Z < 30Z⊙). I find that both density and metallicity change the ionization status of the gas. I provide numerical cooling functions by describing the total cooling as a sum of four parts: that due to H&He, the heavy elements, electron-electron bremsstrahlung, and grains. Finally, I also provide a function giving the electron fraction, which can be used to convert the cooling function into a cooling rate. Last, I extend the cooling-function study to the seldom-explored low-temperature range (T < 104 K). For primordial gas, gas lacking elements heavier than B, I find that radiative attachment and Compton recoil are important cooling processes when the gas kinetic temperature is lower than the temperature of the cosmic microwave background. I also find that collisional de-excitation of HD and H2 is not important above 1000K unlike claims of previous studies. For the dust-free solar case, we identify water as the dominant coolant in high density-environments. We also analyze the parameter ranges where metal, metal molecules, or all molecules, dominate the total cooling. We provide the density, above which the metal or metal molecules become the dominant coolants, as a function of temperature and metallicity. For the ISM case, with dust and depleted abundances, we find that dust does not directly cool the gas. Rather, dust modifies he cooling by affecting the chemistral balance. Similar to the high-temperature case, I also provide numerical cooling data.

There exists many astronomical objects that vary in brightness. Objects such as variable stars like the Cepheids that periodically expands and contracts their outer layers, or the active galactic nuclei (AGN) where accretion of matter into a black hole generates a often varying brightness. Several candidates for being such variable objects have been identified as a result of the Vanishing and Appearing Stuff during a Century of Observations (VASCO) project. These candidates were then narrowed down to a handful that showed variability towards the infrared part of the spectrum. This bachelor’s thesis then aims to look further into these candidates using various databases and catalogues taking data from several sky surveys (SDSS, 2MASS etc). This is done to get better overview of the objects lightcurve over a bigger part of the spectrum, to establish whether the variability is real or a result from errors and to form a hypothesis of what kind of objects they could be. The result obtained from the data from the surveys points towards all the objects being real variable objects. The hypothesis is that all the objects are AGN’s that vary in brightness.
Det existerar många olika astronomiska objekt som varierar i ljusstyrka. Allt från variabla stjärnor som Cepheiderna som periodvis expanderar och kontraherar dess yttre skikt, till aktiva galaxkärnor där ackretion av materia in i ett svart hål genererar en ofta varierande ljusstyrka. Ett flertal kandidater för just sådana varierande objekt har identifierats som ett resultat av VASCO projektet. Dessa kandidater har sedan skalats ner till en handfull mängd kandidater som visade variation mot den infraröda delen av spektrumet. Detta kandidatarbete siktar på att vidare undersöka dessa kandidater genom att använda diverse astronomiska databaser och kataloger för att få data från flera kartläggningsprojekt (t.ex. SDSS, 2MASS etc). Detta är gjort för att få en bättre överblick över objektens ljuskurvor över en större del av spektrumet, att fastställa ifall objekten är riktiga variabla objekt eller uppstått på grund av diverse fel, samt att framställa en hypotes för vad det är för typ av objekt de kan vara. Resultaten från undersökningarna pekar på att alla objekten är riktiga variabla objekt. Hypotesen är att alla av objekten är aktiva galaxkärnor som varierar i ljusstyrka.

Recommendation systems have been widely utilized in e-commerce settings to aid users through their shopping experiences. The principal advantage of these systems is their ability to narrow down the purchase options in addition to marketing items to customers. However, a number of challenges remain, notably those related to obtaining a clearer understanding of users, their profiles, and their preferences in terms of purchased items. Specifically, recommender systems based on collaborative filtering recommend items that have been rated by other users with preferences similar to those of the targeted users. Intuitively, the more information and ratings collected about the user, the more accurate are the recommendations such systems suggest. In a typical recommender systems database, the data are sparse. Sparsity occurs when the number of ratings obtained by the users is much lower than the number required to build a prediction model. This usually occurs because of the users’ reluctance to share their reviews, either due to privacy issues or an unwillingness to make the extra effort. Grey-sheep users pose another challenge. These are users who shared their reviews and ratings yet disagree with the majority in the systems. The current state-of-the-art typically treats these users as outliers and removes them from the system. Our goal is to determine whether keeping these users in the system may benefit learning. Thirdly, cold-start problems refer to the scenario whereby a new item or user enters the system and is another area of active research. In this case, the system will have no information about the new user or item, making it problematic to find a correlation with others in the system. This thesis addresses the three above-mentioned research challenges through the development of machine learning methods for use within the recommendation system setting. First, we focus on the label and data sparsity though the development of the Hybrid Cluster analysis and Classification learning (HCC-Learn) framework, combining supervised and unsupervised learning methods. We show that combining classification algorithms such as k-nearest neighbors and ensembles based on feature subspaces with cluster analysis algorithms such as expectation maximization, hierarchical clustering, canopy, k-means, and cascade k-means methods, generally produces high-quality results when applied to benchmark datasets. That is, cluster analysis clearly benefits the learning process, leading to high predictive accuracies for existing users. Second, to address the cold-start problem, we present the Popular Users Personalized Predictions (PUPP-DA) framework. This framework combines cluster analysis and active learning, or so-called user-in-the-loop, to assign new customers to the most appropriate groups in our framework. Based on our findings from the HCC-Learn framework, we employ the expectation maximization soft clustering technique to create our user segmentations in the PUPP-DA framework, and we further incorporate Convolutional Neural Networks into our design. Our results show the benefits of user segmentation based on soft clustering and the use of active learning to improve predictions for new users. Furthermore, our findings show that focusing on frequent or popular users clearly improves classification accuracy. In addition, we demonstrate that deep learning outperforms machine learning techniques, notably resulting in more accurate predictions for individual users. Thirdly, we address the grey-sheep problem in our Grey-sheep One-class Recommendations (GSOR) framework. The existence of grey-sheep users in the system results in a class imbalance whereby the majority of users will belong to one class and a small portion (grey-sheep users) will fall into the minority class. In this framework, we use one-class classification to provide a class structure for the training examples. As a pre-assessment stage, we assess the characteristics of grey-sheep users and study their impact on model accuracy. Next, as mentioned above, we utilize one-class learning, whereby we focus on the majority class to first learn the decision boundary in order to generate prediction lists for the grey-sheep (minority class). Our results indicate that including grey-sheep users in the training step, as opposed to treating them as outliers and removing them prior to learning, has a positive impact on the general predictive accuracy.