67 research outputs found
Automatic morphological parsing of Old Irish verbs using finite-state transducers
No full textThe topic of this paper constitutes the main part of a recently finished Ph.D. project carried out by the author which investigates how computational methods can be employed to map cognate verb forms in Early Irish (ca. 7th–12th centuries A.D.) and Modern Irish (ca. 1200 onwards). This paper discusses the development of a finite-state morphological transducer using foma (Hulden, 2009) for the Old Irish language (ca. 7th–9th centuries A.D.), focusing on verbs. Two main challenges are discussed. First, different practices of word segmentation have significant repercussions for the encoding of dependencies both on and beyond the word level. A second challenge is complex verb stem formation and considerable stem allomorphy. This has been tackled by operating with “monolithic stem” entries for each verb lemma, i.e., synchronic, invariable hard-coded stems, representing a semi-surface-level base form
Automatic morphological analysis and interlinking of historical Irish cognate verb forms
Get PDFThe main aim of the author’s research project is to use computational approaches
to gain more insight into the historical development of Irish verbs. One of the objectives is to investigate how a link between the electronic Dictionary of the Irish
language (eDIL),1 covering the period c. 700–c. 1700, but focussing on Early Irish
(7th–12th centuries), and the nascent Foclóir Stairiúil na Gaeilge ‘The Historical
Dictionary of Irish’,
2 covering the period 1600–2000, could be implemented. Such
a link will be hugely beneficial for scholars operating at the intersection of the medieval and modern period (see Table 1), who currently lack a comprehensive lexical resource for the “intermediate” early modern period.This paper stems from research carried out during a
Government of Ireland Postgraduate Scholarship (GOIPG/2017/1808) funded by
the Irish Research Council. The author would also like to acknowledge the
anonymous reviewer for helpful feedback and the editors for seeing this publication through.Peer reviewe
Boundary Layer Separation: Diagnostics and Control
No full textThe research presented in this thesis focuses on boundary layer separation and, more specifically, on the related physical mechanisms, such as laminar to turbulent transition, with a vision towards effective separation control. The work is divided in three parts, each corresponding to a different separation scenario. The supporting data is experimental, obtained by means of particle image velocimetry. The first and major part regards the phenomenon of laminar separation bubbles. The spatial and temporal response characteristics of a flat plate laminar separation bubble to impulsive forcing are first investigated in order to shed light on the processes of flapping and bursting. The impulsive disturbance is introduced twodimensionally with a dielectric barrier discharge plasma actuator. The disturbance develops into a wave packet that causes rapid shrinkage of the bubble in both upstream and downstream directions. This is followed by bubble bursting, during which the bubble elongates significantly, while vortex shedding strength in the aft portion of the bubble is reduced. Duration of the recovery of the bubble to its unperturbed state is independent of the forcing amplitude. At the same time, linear stability analysis shows that the growth rate and the frequency of the most unstable mode decreases for increasing forcing amplitude. Throughout recovery, growth rates are directly proportional to the shape factor, indicating that bursting and flapping mechanisms are driven by altered stability characteristics due to variations in incoming disturbances. It is found that the stability of the flow changes only when disturbances interact with the shear layer breakdown and reattachment processes, supporting the notion of a closed feedback loop
Ideam Generalem Nutritionis Solidarum & Fluidarum Corporis Humani Partium
No full textquod ... præside ...Francisco Josepho de Oberkamp ... publico ac solenni eruditorum examini submittit author Theodorus Ernest. Jos. Moers Agrippinas ...Vorlageform des Erscheinungsvermerks: Heidelbergæ, typis Joannis Jacobi Hæner, Typogr. Aul. Academ.Heidelberg, Univ., Diss., 174
I commenti di Taleleo e Teodoro di Ermopoli a C. 2.4.29: un raffronto in tema di transazione
No full textThalelaeus’ and Theodorus’ commentaries on a short rescript by Diocletianus and Maximianus give the
author a chance to compare the teaching techniques of the antecessores and scholastikoi and also their
different level of depth in the study of Justinianic law
El intelecto agente en el siglo XIV / "Intellectum agens" in the 14th Century
No full textIn this paper we study the agent intellect in the XIV century. This work is divided into 3 different parts: Averroism (Ioannes de Janduno, Marsilius Paduanus, Paulus ofVenice andan anonymous author). Nominalism (Gulielmus of Ockham and Ioannes Buridanus), eclecticism (Theodorus Metochites and Petrus of Ailly) and reductionism (Nicolas Oresmes). Potencialism (Aegidius Romanus, Radulfus Brito, Walter Burley andan another anonymous author).</jats:p
The near-wake of discrete roughness elements on swept wings: Tomographic PTV measurements
No full textThis work presents the first reported experimental characterization of the flow field in the direct vicinity of discrete roughness elements (DRE), in a swept wing boundary layer. High magnification tomographic Particle Tracking Velocimetry (3D-PTV) measurements are used to acquire time-averaged velocity and standard deviation fields in a 3D volume directly aft of the DRE elements. The collected data detail the near-element flow topology, providing information on the developing wake and emerging flow structures, their organization and amplitude evolution. A transient growth behaviour is identified in the element wake, while onset and growth of crossflow instabilities is observed further downstream. As such, the near element flow is confirmed to be a fundamental part of the receptivity process, contributing in setting the initial amplitudes for the crossflow instability evolution.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.AerodynamicsWind Energ
The effects of surface cooling on the stability of a flat-plate boundary layer in subsonic flow
No full textThe transition behaviour of a boundary layer with zero pressure gradient in a low-subsonic freestream is examined for a set of wall temperatures below the freestream temperature. Solutions of the boundary layer provided by both an incompressible and a compressible numerical flow solver are compared to wind tunnel measurements on a uniformly cooled section of a flat plate. The compressible solver features a temperature dependence of the fluid properties, which proves to be crucial for modeling the stability of a thermal boundary layer. Thermal images of the surface show that the spanwise-averaged transition front moves downstream with decreasing wall-to-freestream temperature ratio. At the streamwise station where no frictional heating due to turbulent structures is observed, T-S waves are detected in the measured velocity fluctuation profiles. The experimental data show good correspondence with the numerical linear stability predictions here. Further downstream, where streaks of transition occur, T-S waves can no longer be distinguished, and it is likely that non-linear effects have overtaken the boundary layer flow here. The absolute amplitude and the amplitude growth rate of the velocity perturbations both decrease with the wall temperature in the region where T-S waves are seen, and even more in the non-linear region. It is concluded that uniform surface-cooling stabilizes the boundary layer on a flat plate in an incompressible freestream, but a variable-fluid property solver is required to model the stability characteristics.Aerospace Engineerin
Application of Acoustic Metamaterials in Boundary Layer Instability Control
No full textTo achieve delay of laminar-to-turbulent transition of boundary layers, the application of acoustic metamaterial concepts is investigated. This is done analytically, numerically and experimentally by studying the interaction between a Helmholtz resonator and a TS wave. A Helmholtz resonator can serve as a meta-atom in a metamaterial. The desired wall controller property of a metamaterial to suppress TS waves is evaluated. This study shows that TS wave attenuation is achieved if the wall-normal velocity from a metamaterial is in-phase with the TS wave pressure. TS wave amplification is obtained if the pressure and velocity are more than (approximately) 90 degrees out of phase. The p-v phase relation corresponding to a Helmholtz resonator only remains in the amplification regime. Therefore, the conclusion is drawn that a single Helmholtz resonator can only amplify TS waves. If an acoustic metamaterial concept is found where pressure and wall-normal velocity are in-phase, this can be useful in boundary layer instability control.Aerospace Engineering | Aerodynamics and Wind Energ
Theodorus Boilas Muzalon, Contra Beccum
No full textThe RAP online database offers the first comprehensive catalogue of polemical literature related to the schism between the Roman Catholic and Orthodox Churches from the 9th to the 16th century and can be described as an ideal continuation of the *Clavis Patrum*.
Each entry identifies the work (often unpublished or newly discovered in manuscript catalogs), lists its various titles (since medieval texts often lack stable titles), provides incipit and explicit (with possible variations), and examines the manuscript tradition and foliation (by reviewing catalogs or manuscripts, verifying dates, folios, etc.). It also includes relevant bibliography (critical editions and studies), identifies the author (using prosopographical studies, dictionaries, repertories, sigillography, etc.), and provides essential biographical details. Each work is classified by literary genre (e.g., treatise, dialogue), the corresponding Byzantine term, and the main polemical themes (e.g., Filioque, Azymes, Purgatory), and is assigned a unique RAP identification number
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