154 research outputs found
Characterization of collective phenomena in cuprate superconductors by momentum-resolved electron energy loss spectroscopy
No full text"There exists a wide variety of strongly correlated electronic materials, including high temperature superconductors, exotic topological insulators, and charge density wave materials, that exhibit emergent behavior that cannot be understood through current theories of metals and insulators. These materials are classified by the low temperature ordered phases these materials take on, and there may be several ordered phases interacting over the various regions of phase space. High temperature superconductors, for example, may also exhibit Mott insulator, charge density wave, spin glass, and pseudogap phases in their phase diagram. The current consensus in describing most strongly correlated electron systems is, at best, qualitative, and understanding these ordered phases, the mechanisms that drive them, and their relation to related emergent phenomena is necessary for developing a microscopic understanding of this class of materials.
The electron-electron interactions that drive the collective electronic state can be described by the dynamic charge susceptibility, χ(q,ω). This quantity encodes information about the propagation of density fluctuations in a system—the collective ""sloshing"" of electrons—as mediated by bosonic excitations. In order to measure this quantity, we have developed a new experimental technique, momentum-resolved electron energy loss spectroscopy (M-EELS). As a part of this development, we derived the theoretical framework for describing the scattering cross section in terms of the imaginary part of the dynamic susceptibility, χ''(q,ω), and implemented the software and hardware stack necessary to perform this measurement. Using this technique, we are able to measure finite momentum charge dynamics at 2 meV energy scales.
We used M-EELS to investigate materials in the Bi2Sr2CaCu2O8+δ (Bi2212) family of cuprate high temperature superconductors. In studying optimally doped crystals, we have performed a full energy and momentum characterization of the low-energy dynamic susceptibility. Our measurement identifies known phonon modes, as previously seen in Raman scattering, infrared spectroscopy, and HR-EELS. Using a one-loop correction model, we have identified these modes as giving rise to the kinks in the electron spectral function as seen in ARPES, suggesting that these modes are related to the emergent phenomena exhibited in these materials. Furthermore, we observe a background in the optimally doped spectra that extends out to ∼1 eV, consistent with a marginal Fermi liquid description of these materials.
In addition, from our measurements of the static component of the charge susceptibility, we have discovered diffuse, short-range charge order in optimally doped Bi2212. Proximity to the charge order state is suspected to be important in unconventional superconductivity, and has previously been seen in many families of high temperature superconductors, including underdoped Bi2212. At underdoping, we observe sharp elastic peaks consistent with previous charge order observations. At optimal doping, we observe diffuse scattering at low temperatures that exhibits a quasielastic broadening. This is a signature of the emergence of fluctuating order on a time scale of 180 fs."Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2019-05-01The student, Sean Vig, accepted the attached license on 2017-03-08 at 11:34.The student, Sean Vig, submitted this Dissertation for approval on 2017-03-08 at 11:52.This Dissertation was approved for publication on 2017-03-09 at 09:53.DSpace SAF Submission Ingestion Package generated from Vireo submission #10580 on 2017-08-10 at 15:04:37Made available in DSpace on 2017-08-10T20:32:33Z (GMT). No. of bitstreams: 2
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Previous issue date: 2017-03-09Embargo set by: Colleen Fallaw for item 102714
Lift date: 2019-08-10T21:27:21Z
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VIG ISTVÁN: HORVÁT NYELVTAN: Budapest: ELTE, BTK Szláv Filológiai Tanszék, 2008. (Opera Slavica Budapestinensia, Linguae Slavicae). 356 o.
No full textVIG ISTVÁN: HORVÁT NYELVTAN
In the article, author presents and evaluates the work of István Vig, Horvát Nyelvtan (Croatian Grammar).Avtor v prispevku predstavlja in ocenjuje delo Istvána Viga Horvát Nyelvtan (Hrvaška slovnica)
What have we learned about mortgage default?
No full textBy the end of 2009, one out of every 11 mortgages was seriously delinquent or in foreclosure. Economists have devoted considerable energy over the past several years to understanding the underlying causes of this increase in defaults. One goal is to provide a guide to dealing with the existing problems. In addition, a better understanding may help avoid future problems. In “What Have We Learned About Mortgage Default?” Ronel Elul reviews recent research that has shed light on two areas: the extent to which securitization is responsible for the increase in default rates; and the relative contributions of negative equity, compared with “liquidity shocks,” in explaining mortgage default.Mortgage loans ; Default (Finance)
Securitization and mortgage default
No full textThe academic literature, the popular press, and policymakers have all debated securitization's contribution to the poor performance of mortgages originated in the run-up to the recent crisis. Theoretical arguments have been advanced on both sides, but the lack of suitable data has made it difficult to assess them empirically. The author examines this issue by using a loan-level data set from LPS Analytics, covering approximately two-thirds of the mortgages originated in 2005 and 2006, and including both securitized and nonsecuritized loans. ; The author finds evidence that privately securitized loans do indeed perform worse than observably similar, nonsecuritized loans. Moreover, this effect is strongest in prime mortgage markets, which have not been studied in the previous literature. For example, a typical prime loan becomes delinquent at a 20 percent higher rate if it is privately securitized, ceteris paribus. This is consistent with the existence of adverse selection; that is, that lenders used information not available to investors to securitize loans that were riskier than they otherwise appeared. By contrast, for subprime mortgages, the impact of private securitization is concentrated in low or no-documentation loans; this latter result is consistent with previous work such as Keys et al. (2009).Mortgage-backed securities ; Default (Finance)
Pratiques et représentations religieuses à Madagascar au temps de Lars Vig (missionnaire et ethnographe), 1875-1903. Textes et contexte
No full textReligious practices and representations in Madagascar in the time of Lars Vig (missionary and ethnographer), 1875-1903. Texts and context. Starting with a study of contemporary religious practices in Madagascar’s Highlands (published in 2006), the author takes a fresh look at the Norwegian Lutheran archives compiled by L. Vig and A. Valen, missionaries in Madagascar at the end of the nineteenth century (the nms Archives in Stavanger). In them we find the oldest descriptions of religious practices and representations in the region. The aim is to grasp the phases of the “encounter” and religious conversion as shown in the archives, and the modes of “conversation” and religious production that are always found at work these days in processes of affiliation and religious practices. The work consisted of identifying both the contents of certain texts and, at the same time, the context in which they were recorded. An examination of the collection brings to light the role of the informants and gives details about the Madagascan society in which Vig moved, his working methods and his experience. This work looks at various levels of texts, from fieldwork research to articles prepared for publication. This collection can be compared with the Madagascan Tribunal Archives from the same period, more recent missionary archives and current Madagascan writings
Pratiques et représentations religieuses à Madagascar au temps de Lars Vig (missionnaire et ethnographe), 1875-1903. Textes et contexte
No full textPratiques et représentations religieuses à Madagascar au temps de Lars Vig (missionnaire et ethnographe), 1875-1903. Textes et contexte. À partir d’une étude des pratiques religieuses contemporaines sur les Hautes Terres malgaches (publiée en 2006), l’auteur porte un regard nouveau sur les archives luthériennes norvégiennes constituées par L. Vig et A. Valen, missionnaires à Madagascar à la fin du xixe siècle (Archives nms de Stavanger). On y trouve les descriptions les plus anciennes de pratiques et de représentations religieuses pour cette région. Le but est de saisir les étapes de la « rencontre » et de la conversion religieuse que montrent ces archives, et les modes de « conversation » et de production religieuse, qu’on retrouve toujours à l’œuvre aujourd’hui dans les processus d’affiliations et de pratiques religieuses. Le travail a consisté à identifier en même temps le contenu de certains textes et le contexte dans lequel ceux-ci ont été recueillis. L’examen des fonds fait apparaître des personnages d’informateurs, et donnent des détails sur la société malgache que Vig côtoyait, sur ses méthodes de travail et son expérience. On y découvre les niveaux de textes élaborés entre recueils de terrain et maquettes de publication. Ce fonds peut être mis en regard des Archives des tribunaux malgaches de la même époque, d’archives missionnaires plus récentes et d’écrits malgaches actuels.Religious practices and representations in Madagascar in the time of Lars Vig (missionary and ethnographer), 1875-1903. Texts and context. Starting with a study of contemporary religious practices in Madagascar’s Highlands (published in 2006), the author takes a fresh look at the Norwegian Lutheran archives compiled by L. Vig and A. Valen, missionaries in Madagascar at the end of the nineteenth century (the nms Archives in Stavanger). In them we find the oldest descriptions of religious practices and representations in the region. The aim is to grasp the phases of the “encounter” and religious conversion as shown in the archives, and the modes of “conversation” and religious production that are always found at work these days in processes of affiliation and religious practices. The work consisted of identifying both the contents of certain texts and, at the same time, the context in which they were recorded. An examination of the collection brings to light the role of the informants and gives details about the Madagascan society in which Vig moved, his working methods and his experience. This work looks at various levels of texts, from fieldwork research to articles prepared for publication. This collection can be compared with the Madagascan Tribunal Archives from the same period, more recent missionary archives and current Madagascan writings
Stimulation of joint attention in children aged 17-30 months with positive screening rate of autism using VIG method
No full textNÁZEV PRÁCE: Stimulace sdílené pozornosti u dětí s pozitivním screeningem autismu ve věku 17-30 měsíců za využití metody VTI TITLE: Stimulation of joint attention in children aged 17-30 months with positive screening rate of autism using VIG method. AUTHOR: Mgr. Romana Straussová DEPARTMENT: Special Education SUPERVISOR: prof. RNDr. PhDr. Marie Vágnerová, CSc. ABSTRACT: The subject of this dissertation is research of the impact of the modified VIG intervention method applied in 16 families with children with Autism Spectrum Disorder (ASD), the children being at the age of 17-30 months when entering the project. The intervention and subsequent monitoring of the development took place during the years 2011- 16. The aim of the study was to determine whether it is possible to positively influence the development of a child with autism without the use of intensive therapy guided by a professional, using only parent behavioral training and with the support of attachment behavior. The subjects of research evaluation were the degree of the child's development and the father's and mother's experience with parental roles in relation to the child's disability. The results were surprisingly positive. 38 % (6 children) stepped out of the clinical to nonclinical, 25 % still show the picture of developmental dysphasia, 5..
Anatomy of the Beginning of the Housing Boom: U.S. Neighborhoods and Metropolitan Areas, 1993-2009
No full textWe provide novel estimates of the timing, magnitudes, and potential determinants of the start of the last housing boom across American neighborhoods and metropolitan areas (MSAs) using a rich new micro data set containing 23 million housing transactions in 94 metropolitan areas between 1993 and 2009. We also match transactions data with loan information, enabling us to observe household income and other demographics for each neighborhood. Five major findings are reported. First, the start of the boom was not a single, national event. Booms, which are defined by the global breakpoint in an area’s price appreciation series, begin at different times over a decade-long period from 1995-2006. Second, the magnitude of the initial jump in house price appreciation at the start of the boom is economically, not just statistically, significant. On average, log house prices are over four points higher during the first year of the boom relative to the previous twelve month period for both MSAs and neighborhoods. There is no evidence that price growth was trending up prior to the start of the boom. Third, local income is the only potential demand shifter found that also had an economically and statistically significant change around the time that local housing booms began. Contemporaneous local income growth is large enough to account for half or more of the initial jump in house price appreciation. While these estimates indicate that the beginning of the boom was fundamentally justified on average, they do not imply that what followed was rational. Fourth, there is important heterogeneity in that result. Income growth is large and jumps at the same time as house price appreciation in areas that boomed early and have inelastic supplies of housing, but not in late booming areas and those with elastic supply sides. Fifth and finally, none of the demand-shifters analyzed show positive pre-trends, but some such as the share of subprime lending, do lag the beginning of the boom. This suggests that key players in the lending market more responded to the boom, rather than caused it to start.
Stimulation of joint attention in children aged 17-30 months with positive screening rate of autism using VIG method
No full textNÁZEV PRÁCE: Stimulace sdílené pozornosti u dětí s pozitivním screeningem autismu ve věku 17-30 měsíců za využití metody VTI TITLE: Stimulation of joint attention in children aged 17-30 months with positive screening rate of autism using VIG method. AUTHOR: Mgr. Romana Straussová DEPARTMENT: Special Education SUPERVISOR: prof. RNDr. PhDr. Marie Vágnerová, CSc. ABSTRACT: The subject of this dissertation is research of the impact of the modified VIG intervention method applied in 16 families with children with Autism Spectrum Disorder (ASD), the children being at the age of 17-30 months when entering the project. The intervention and subsequent monitoring of the development took place during the years 2011- 16. The aim of the study was to determine whether it is possible to positively influence the development of a child with autism without the use of intensive therapy guided by a professional, using only parent behavioral training and with the support of attachment behavior. The subjects of research evaluation were the degree of the child's development and the father's and mother's experience with parental roles in relation to the child's disability. The results were surprisingly positive. 38 % (6 children) stepped out of the clinical to nonclinical, 25 % still show the picture of developmental dysphasia, 5..
Nyomárkay István: Rövid horvát és szerb nyelvtörténet (Kurze Geschichte des Kroatischen und des Serbischen): Budimpešta: ELTE Inštitut za slovansko in baltsko filologijo, 2007. Opera Slavica Budapestinensia. Linguae Slavicae. S. 292.
No full textNyomárkay István: Rövid horvát és szerb nyelvtörténet (A Brief History of Croatian and Serbian)
The author of the article presents the first history of Croatian and Serbian, written in Hungarian; its author is István Nyomárkay.Avtor prispevka predstavlja prvo zgodovino hrvaščine in srbščine, napisano v madžarščini; njen avtor je István Nyomárkay
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