77 research outputs found
Replication code and pseudodata for the paper "Counterparty Risk: Implications for Network Linkages and Asset Prices"
No full textReplication package for: Grigoris, F., Hu, Y. and Segal, G. Counterparty Risk: Implications for Network Linkages and Asset Prices, Review of Financial Studies, forthcoming (DOI: 10.1093/rfs/hhac044). The compressed archive includes a README file, describing all pseudo data and code modules
The term structure of municipal bond yields, local economic conditions, and local stock returns
No full textThis study shows that the municipal yield curve is informative about local economic outcomes. Controlling for Treasury yields, a flatter municipal yield curve not only predicts deteriorating local economic conditions, such as higher unemployment rates and more macroeconomic uncertainty, but also signals greater risk for locally headquartered firms. An investment strategy that exploits this fact by buying (selling) the firms located in states where municipal yield curve is relatively flat (steep) earns an excess return that exceeds 5% per annum. These novel empirical results indicate that the municipal debt market provides valuable information about the trajectories and risks of local economies.Doctor of Philosoph
Text Extraction and Web Searching in a Non-Latin Language
No full textRecent studies of queries submitted to Internet Search Engines have shown that
non-English queries and unclassifiable queries have nearly tripled during the
last decade. Most search engines were originally engineered for English. They
do not take full account of inflectional semantics nor, for example, diacritics or
the use of capitals which is a common feature in languages other than English.
The literature concludes that searching using non-English and non-Latin based
queries results in lower success and requires additional user effort to achieve
acceptable precision.
The primary aim of this research study is to develop an evaluation methodology
for identifying the shortcomings and measuring the effectiveness of
search engines with non-English queries. It also proposes a number of solutions
for the existing situation. A Greek query log is analyzed considering the morphological
features of the Greek language. Also a text extraction experiment
revealed some problems related to the encoding and the morphological and
grammatical differences among semantically equivalent Greek terms. A first
stopword list for Greek based on a domain independent collection has been
produced and its application in Web searching has been studied. The effect of
lemmatization of query terms and the factors influencing text based image retrieval
in Greek are also studied. Finally, an instructional strategy is presented
for teaching non-English students how to effectively utilize search engines.
The evaluation of the capabilities of the search engines showed that international
and nationwide search engines ignore most of the linguistic idiosyncrasies
of Greek and other complex European languages. There is a lack of
freely available non-English resources to work with (test corpus, linguistic resources,
etc). The research showed that the application of standard IR techniques,
such as stopword removal, stemming, lemmatization and query expansion,
in Greek Web searching increases precision.
i
Structural health monitoring of adhesively-bonded hybrid joints by acoustic emission
No full textThe increasing use of Adhesively-bonded joints in industrial applications resulted in more attention to damage assessment in these joints. The aim of the present study is to characterize the damage in bi-material double-lap adhesively-bonded joints by Acoustic Emission (A E). Two different structural adhesives, representing a ductile (Methacrylate-based) and brittle (epoxy-based) types, were used to bond C F R P skins to a steel core. The fabricated joints were loaded in tension while damage evolution was monitored by A E . Due to the difference in the fracture nature of the adhesives "brittle vs. ductile", different damage mechanisms occurred in the specimens; including adhesive layer failure, steel deformation, adhesive/adherends interfacial debonding and delamination in the C F R P skin. In order to distinguish and classify these damage types by A E, the AE features of each damage mechanism were first obtained by conducting some standard tests on the individual constituent materials. Then, these AE reference patterns were used to train an ensemble decision tree classifier. Finally, the trained model classified the AE signals of the double-lap tests and the images captured by camera were utilized to verify AE results. This study demonstrates the potential of AE technique for damage characterization of the adhesively-bonded bi-material joints.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Structural Integrity & Composite
3-D pain drawings-mobile data collection using a PDA
No full textA large number of the adult population suffers from some kind of back pain during their lifetime. Part of the process of diagnosing and treating such back pain is for a clinician to
collect information as to the type and location of the pain that is being suffered.Traditional approaches to gathering and visualizing this pain data have relied on simple 2-D representations of the human body, where different types of sensation are recorded with various monochrome symbols. Although patients have been shown to prefer such drawings to traditional questionnaires, these pain drawings can be limited in their ability to accurately record pain. The work described in this paper proposes an alternative that uses a 3-D representation of the human body, which can be marked in color to visualize and record the pain data. This study has shown that the new approach is a promising development in this area of medical practice and has been positively received by patients and clinicians alike
Audience Evaluations of Contrasting Types of Literature Event: Author Readings and Poetry Slams
No full textIn den 1990er- und den frühen 2000er-Jahren hat die Anzahl der Literaturveranstaltungen stark zugenommen. Neben die klassische Autor*innenlesung traten neue Formate wie Lesebühne und Poetry Slam. Ausgangspunkt dieser explorativ ausgerichteten literatursoziologischen Pilotstudie – eine der ersten umfassenden Arbeiten über Literaturveranstaltungen im deutschsprachigen Raum – war die Frage danach, was Besucher*innen an unterschiedlichen Literaturveranstaltungen gefällt und warum. Um diese Frage zu beantworten, wurden die Wertungen und Wertmaßstäbe von Besucher*innen ausgewählter Literaturhauslesungen und Poetry Slams in München und Stuttgart der Jahre 2009/2010 untersucht, also Veranstaltungen zweier im Feld der Literaturveranstaltungen deutlich voneinander abgegrenzter Formate. Empirische Grundlage der Studie bilden ca. 1.500 Fragebogenbefragungen und ca. 100 Interviews bei/im Anschluss an 13 Veranstaltungen; die hieraus resultierenden quantitativen wie qualitativen Daten werden mithilfe verschiedener Methoden der empirischen Sozialforschung triangulär aufeinander bezogen. Um eine Grundlage für die Entwicklung von Untersuchungskorpus und Erhebungsinstrumenten zu schaffen, wird basierend auf Goffmans Rahmentheorie zunächst ein Modell der Bestandteile von Literaturveranstaltungen und Auftritten mit Literatur entwickelt sowie im Anschluss hieran eine Typologie der Literaturveranstaltungen, die zwischen Lesung, Lesebühne, Literaturlabor, Open Mike, Poetry Slam und Literaturfestival differenziert. Ausgehend hiervon, von Pierre Bourdieus Feldtheorie und einer sozialkonstruktivistischen Wertungstheorie wird anschließend die Geschichte des Literaturveranstaltungsfeldes seit den 1990er-Jahren dargestellt, aus der wiederum die zu untersuchenden Veranstaltungsformate und die voraussichtlich für Zuschauer*innenwertungen relevanten Wertmaßstäbe abgeleitet werden. Die Auswertung der Daten ist fokussiert auf mehrere Schwerpunkte, geht aber über diese hinaus: (1) Faktorenanalytisch werden acht distinkte Wertmaßstabsmuster herausgearbeitet, die in den Autor*innenlesungs- und Poetry-Slam-Publika vertreten sind. Sie zeigen ein Spannungsverhältnis von gegenstandsbezogener und selbstbezogener Rezeption auf, das die erwartete Differenz von bildungskulturell und populärkulturell geprägter Rezeption bei den beiden Formaten Lesung und Poetry Slam spezifiziert; zudem wird die formatsspezifische Bedeutung des Geselligkeitserlebens, von körperlicher Erfahrung und Authentizität ebenso untersucht wie die von Wertmaßstäben des sog. Kreativitätsdispositivs (Andreas Reckwitz) u.a.m. Die Wertmuster prägen das Wertungsverhalten der Publika deutlich und hängen stark vom Alter ab, aber auch von anderen in den Blick genommenen Aspekten. (2) Clusteranalytisch lassen sich vier Publikumsgruppen mit distinkten Präferenzstrukturen bestimmen, die entweder primär bei den untersuchten Autor*innenlesungen (abgrenzungsbewusste Hochkulturkonsument*innen und bildungskultureller Mainstream) oder bei den Poetry Slams (geschmacklich festgelegte und begeisterungsfähige Eventgänger*innen) zu finden sind. (3) Abschließend wird ein inferenzbasiertes Modell der Informationsverarbeitung herangezogen, um am Beispiel mehrerer Lesungsauftritte (F.C. Delius, Eva Menasse) und Poetry-Slam-Auftritte (Bumillo, Pauline Füg, Andy Strauß, „Der Kaiser“) zu zeigen, wie die konkrete Wertungspraxis durch die herausgearbeiteten Wertstrukturen einerseits und andererseits durch situationelle Besonderheiten, insbesondere die Salienz von Auftrittsaspekten, bedingt ist.
Anmerkung der Redaktion:
"Ergänzende Materialien zu dieser Publikation (Videos, Tabellen, Anhänge) stehen digital zur Verfügung. Sie werden in Kürze auf entsprechenden Fachrepositorien bereitgestellt und von hier aus verlinkt.“The number of literature events increased sharply during the 1990s and early 2000s. New formats, including poetry slams and author collective performances [Lesebühnen], became prominent, alongside classic author readings. This pilot study – located in both sociology and literary studies, exploratory, and one of the first comprehensive investigations of literature events in the German-language sphere – developed from the question of what audiences at diverse literature events like about them, and why. To answer this, value measurements and evaluations were collected, and examined, from responses to selected events at so called ‘houses of literature’ [Literaturhäuser] and at poetry slams in Munich and Stuttgart, 2009–2010. These two event formats differ decisively. The study’s empirical foundations are the c. 1500 questionnaires and the c. 100 interviews conducted during / following thirteen events. The quantitative and qualitative data resulting thereby is brought into triangular relation using various methods from empirical social research. Goffman’s frame analysis is utilized to create a foundation for the development of a data corpus to be investigated, and to forge data collection instruments. First, a model of the components of literature events and of literature-based performances is established. Subsequently, a typology of events is laid out, which differentiates between readings, author collective events, ‘literature laboratories’, open mikes, poetry slams, and literature festivals. Proceeding from this empirical foundation, from Pierre Bourdieu’s theory of social fields, and from a social constructivist theory of value, the history of the literature events field since the 1990s is presented. From this can be extrapolated which event formats are to be investigated, and which value-measurements will presumably be relevant to the audience members’ evaluations. Several priorities are set in the data evaluation stage, which also, however, goes beyond these foci: (1) Through factor analysis, eight distinct value-measurement patterns are identified, which are represented in audiences at author readings and at poetry slams. These demonstrate a strong contrast in audience receptions between those that are object-oriented and those that are self-oriented. This contrast, in relation to the different formats of classic reading and poetry slam, specifies the expected divergence between receptions shaped by pop culture and those shaped by what is commonly seen as highbrow culture. Moreover, aspects of the events’ format-specific significance include: convivial experience; bodily experience; authenticity; and value-measurements pertaining to Andreas Reckwitz’s creativity dispositif. Value patterns clearly impact on the audience members’ evaluation behavior – these depend strongly on age, but also on other aspects looked at. (2) Cluster analysis facilitates the definition of four audience groups with distinct preference structures. These groups can be found either primarily at the author readings examined – the first is ‘highbrow’ consumers, conscious of cultural demarcations, the second an educated, cultural mainstream – or in the two groups going to poetry slams, both experience-and-sensation oriented, the first with less flexible tastes, the second enthusiastic about the new. (3) In conclusion, an inference-based model for information processing is cultivated, to show – using the examples of further public readings (the authors F.C. Delius and Eva Menasse) and poetry slam performances (Bumillo, Pauline Füg, Andy Strauß, and Der Kaiser) – how the concrete praxis of valuation is conditioned by the value structures established, on the one hand, and by situational exceptions, particularly the salience of performance aspects, on the other.
Editor's note: "Supplementary materials to this publication (videos, tables, appendices) are available digitally. They will be made available shortly on appropriate subject repositories and linked from here."2022-02-2
Energy Efficient Spectrum Allocation and Mode Selection for D2D Communications in Heterogeneous Networks
No full textIn this paper, we consider a heterogeneous network consisting of both macro Base Station (MBS) and pico Base Stations (PBSs) in order to provide a spectrum allocation and mode selection in device-to-device (D2D) communications. A number of Component Carriers (CC) are considered available for allocation to the MBS and PBSs that are being utilized through carrier aggregation (CA) while mode selection decisions are made by each BS in order to balance between power consumption minimization and UE data rate requirements. A power minimization (energy-efficient) problem is formulated in order to provide a joint spectrum allocation and mode selection solution. This problem is solved using a state of the art optimization method known as proximal algorithm. First, a non-cooperative (centralized) solution is provided and second, a cooperative (distributed) employing distributed proximal algorithm is devised reducing the induced complexity. The cooperative solution is achieved by implementing distributed alternating direction method of multipliers (D-ADMM). Simulation results are carried out for all cases that reveal the energy efficient spectrum allocation and mode selection according under certain channels' conditions that can balance between achieving high data rate requirements and power minimization. Finally, useful insights are presented such as complexity, convergence, delay and actual implementation of such a solution for the future wireless networks. 2015 IEEE.Manuscript received September 15, 2019; revised January 13, 2020 and March 8, 2020; accepted March 16, 2020. Date of publication May 11, 2020; date of current version May 28, 2020. This work was supported in part by NPRP under Grant NPRP 6-1326-2-532 from the Qatar National Research Fund (a member of Qatar Foundation). The associate editor coordinating the review of this manuscript and approving it for publication was Prof. Pierluigi SALVO ROSSI. (Corresponding author: Fotis Foukalas.) Apostolos Galanopoulos is with Trinity College Dublin, Dublin D02 PN40, Ireland (e-mail: [email protected]).Scopu
Enhanced Bounding Surface Modeling of Sand Behaviour under Multiple Loading Cycles
No full textCyclic behaviour of soil has stimulated researchers for several decades to develop constitutive models that will be able make accurate predictions of soil behaviour and at the same time they will be simple to use. Constitutive models are considered to be more valid compared to empirical models, because they comprise by equations that have actual physical meaning. Bounding surface plasticity theory is widely used by researchers and one of the most well-known models is SANISAND, established by Dafalias and Manzari (2004), which is the base for the model presented in this work.The development of offshore industry during last years, have created the need for models that will be able to simulate soil behaviour under high-cyclic loading, since models like SANISAND were not able to capture the actual number of cycles until liquefaction. This can be done with the incorporation of an additional surface in multi-axial space; the memory surface, which keeps track of the stress history of soil, following the work of Corti (2016). In this thesis the validation of a new, multiple-surface model, that combines the aforementioned theories, was done. This was achieved by using the data base of Wichtmann and Triantafyllidis (2016), who conducted extensive laboratory testing for sand. This database includes monotonic and cyclic tests for sand under a variety of loading conditions and relative densities. Furthermore, this model was used in order to produce cyclic contour diagrams. These diagrams are practical tools that are often used in practice from offshore foundation designers and they can be constructed using a collection of undrained cyclic tests, either triaxial or DSS. Geo-Engineerin
The role of mud on the long-term morphological development of a tidal basin
No full textCivil Engineering and GeosciencesHydraulic EngineeringCivil Engineerin
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