578 research outputs found
Limitations of 2-D Field Structure Assumptions in Electrical Properties Tomography and its 3-D CSI-EPT Solution
No full textCSI-EPT is an Electrical Properties Tomography (EPT) reconstruction method that uses a Contrast Source Inversion (CSI) optimization approach to retrieve the conductivity and permittivity profiles of tissue based on -data. The method can handle variations in tissue profiles and was originally implemented for profile reconstructions in the midplane of a birdcage coil, where the RF field exhibits an E-polarized field structure [1]. Recently, CSI-EPT has been extended to a fully 3-D volumetric reconstruction method that is generally applicable (in- or outside the midplane) and no particular field structure or smoothness is assumed [2]. This is a major step towards turning CSI-EPT into a practical reconstruction method. Unfortunately, the computation times significantly increase (hours or even days, depending on the reconstruction domain of interest) and from this point of view a 2-D approach may be preferable. We show, however, that a 2-D approach is only warranted under very specific circumstances and having an E-polarized field structure is a necessary but not sufficient condition. In particular, we show that to obtain accurate tissue reconstructions based on 3-D -data, it is in general necessary to take all electromagnetic field components into account and a 2-D reconstruction approach will lead to reconstruction artefacts.Signal Processing System
Life in the Promised Land: an English Translation of Max von der Grün's Leben im Gelobten Land
No full textii, 122 p.Do not distribute at the request of the author 8/27/15
Self-reported adherence to physical activity recommendations compared to the IPAQ interview in patients with hypertension
No full textGlaube R Riegel,1 Giulia B Martins,1 Afonso G Schmidt,1 Marcela P Rodrigues,1 Gerson S Nunes,2 Vicente Correa Jr,1,2 Sandra C Fuchs,1 Flavio D Fuchs,1,2 Paula AB Ribeiro,1,3 Leila B Moreira1,4 1Postgraduate Studies Program in Cardiology, School of Medicine, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil; 2Cardiology Division, Hospital de Clínicas de Porto Alegre, Porto Alegre, RS, Brazil; 3Cardiology Division, University of Montreal Hospital Research Centre (CRCHUM), Montréal, QC, Canada; 4Pharmacology Department, Instituto de Ciências Básicas da Saúde (ICBS), Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil Background: Physical activity (PA) is recommended as adjuvant therapy to control blood pressure (BP). The effectiveness of simple recommendations is not clear. We aimed to assess the agreement between self-report of adherence to PA in clinical routine and International Physical Activity Questionnaire (IPAQ) interview and its association with BP control. Methods: A cross-sectional study was conducted with hypertensive outpatients. Adherence to recommendation to PA was assessed by the physician and IPAQ interview. A cutoff of 150 minutes/week was used to classify active or nonactive patients. High sitting time was considered >4 hours/day. A total of 127 individuals (SBP 144.9±24.4 mmHg/DBP 82.0±12.8 mmHg) were included. Results: A total of 69 subjects (54.3%) reported to be active to their physician, whereas 81 (63.8%) were classified as active by IPAQ (6.3% active in leisure time PA). Kappa test was 0.22 (95% CI, 0.06–0.37). The rate of BP control was 45.7%. There was no association with the reported PA assessed by both methods nor with sitting time. Our results demonstrated poor agreement between self-report adherence and IPAQ interview, and neither evaluation was associated with BP control. Conclusion: Our findings underpin evidences that a simple PA recommendation has low association with BP control in clinical settings. Keywords: blood pressure, exercise, treatment adherence, self-report, hypertension, physical activity counselin
Opacity in Tiberian Hebrew: Morphology, not Phonology
No full textThe phenomenon of phonological opacity has been the subject of much debate in recent years, with scholars opposed to the Optimality Theory (OT) research program arguing that opacity proves OT must be false, while the solutions proposed within OT, such as sympathy theory and stratal OT , have proved to be unsatisfying to many OT proponents, who have found these proposals to be inconsistent with the parallelist approach to phonological processes otherwise characteristic of OT. In this paper I reexamine one of the best known cases of opacity, that found in three processes of Tiberian Hebrew (TH), and argue that these processes only appear to be opaque, because previous analyses have treated them as pure phonology, rather than as an interaction between phonology and morphology. Once it is recognized that certain words of TH are lexically marked to end with a syllabic trochee, and that the goal of paradigm uniformity exerts grammatical pressure on phonology, the three processes no longer present a problem to parallelist OT. The results suggest the possibility that all crosslinguistic instances of apparent opacity can be explained in terms of the phonology-morphology interface and that purely phonological opacity does not exist. If this claim is true, then parallelist OT can be defended against its detractors without the need for additional mechanisms like sympathy theory and stratal OT.The definitive version of this paper was published in ZAS Papers in Linguistics 37 (2004) and is available at http://www.zas.gwz-berlin.de/192.htmlGreen, Antony D. (2004). Opacity in Tiberian Hebrew: Morphology, not phonology. In S. Fuchs and S. Hamann (Eds.), Papers in phonetics and phonology, 37, 37 – 70. Berlin: ZAS, Zentrum für Allgemeine Sprachwissenschaft, Sprachtypologie und Universalienforschun
Cello techniques and performing practices in the nineteenth and early twentieth centuries
Get PDFThis thesis comprises a study of cello performance practices throughout the nineteenth century and into the early decades of the twentieth. It is organised in terms of the increasing complexity of the concepts which it examines, as they are to be found in printed and manuscript music, instrumental methods and larger treatises, early recordings, concert reviews and pictures. Basic posture is considered along with different ways of holding the
bow. The development of the tail-pin shows that even when it was widely used, the older posture was still referred to as a model. Some implications for tone quality and tonal
projection are considered in the light of the shape of the arms. Some connections between the cellist's posture and that recommended by etiquette books are explored. The
functionality of the left hand and arm, and the development of modem scale fingerings, show that there was a considerable period of overlap between newer and older practices, with modern scale fingerings evolving over a long period of time. Similarly, views on the function of the right wrist in bowing are shown to change gradually, moving towards a more active upper arm movement with less extreme flexibility of the wrist. Two central expressive techniques especially associated with string playing arc considered in the context of the cello, namely vibrato and portamento. These topics are examined in the light of written indications in music, recommendations in cello treatises, and the practices evidenced in early recordings. The sources for this study can be brought into an overall
framework of a constant dialogue between `theory', as expressed in verbal instructions to the learner, or general a priori reflections about the cello, and `practice', manifested in performing editions and early recordings, or in individual acts of reception. A wide divergence is noted, both between theory and practice in general, and in terms of different styles of playing observable at any one time. It is suggested that tensions between practice
and critical disapproval can be resolved in terms of Lacanian discourse. Several test cases are used in order to compare several different recordings of the same works. The question of the musical character of the cello is discussed in terms of widespread assumptions about its gendered identity. A wide range of sources suggest that this moved from a straightforwardly `masculine' identity expressed through a controlling, elevated eloquence to a less clearly defined one, incorporating the 'feminine', with a greater stress on uninhibited emotional expression. Some performance implications for this change of view are pursued with respect to specific repertoires. Broad conclusions stress the importance of the diversity of performance practices as opposed to unifying generalisations
Dynamic behaviour of wave packets in turbulent jets
No full textThe present study proposes a data-driven strategy to extract the dynamics of wave-packets from low-speed velocity field measurements. The flow field under study is a subsonic turbulent round jet at Re = 33000, measured over a 20-nozzle-diameters domain in the axial direction using low-repetition-rate planar Particle Image Velocimetry. The turbulent features in the jet have been extracted by Proper Orthogonal Decomposition of the jet velocity field over the whole extension of the domain. The modes produced describe the evolution of the turbulent features in the axial and radial directions of the jet. The temporal evolution of turbulent flow structures and the associated pressure fluctuations, which are not directly accessible from the low-speed measurements, have been estimated using an advection-based Galerkin projection model. The extracted velocity/pressure modes describe a set of modulated waves in the axial direction, which shares many similarities with wave-packets already observed in literature. This behaviour suggests that the employed strategy is effective in retrieving the dynamics of wave-packets extending over the entire measurement domain, paving the way to the estimation of their sound emission from low-speed measurements.Wind Energ
Soap bubbles for large-scale PIV in industrial wind tunnels
No full textThis work evaluates the use of helium-filled soap bubbles (HFSB) for Particle Image Velocimetry (PIV) measurements at high Reynolds numbers (up to 3.2 million) in aeronautics. The measurements are performed in the Low Speed Tunnel (LST) of the German-Dutch Wind Tunnels (DNW) using a high-lift airfoil in close-to-stall conditions up to 70 m/s. Experiments using Di-ethylhexyl- sebacat (DEHS) particles are performed for a comparison of the two seeding techniques. The signal to noise ratio of HFSB images was two orders of magnitude larger than that of DEHS, which strongly reduced the unwanted effects of background reflections and light intensity spatial variations, compared to DEHS particle images. The mean velocity field obtained with HFSB exhibits differences typically within 1% of the free stream velocity, when compared to DEHS measurements.Flow Physics and TechnologyAerodynamic
Waterproef: Vier persoonlijke geschiedenissen van de waterbouw
No full textInterviews met een viertal emiritus hoogleraren in de waterbouwkunde over driekwart eeuw waterbouwkunde. Met een naschrift van Marcel Stive en Han VrijlingHydraulicCivil Engineering and Geoscience
Developing Reading Identities: Understanding Issues of Motivation within the Reading Workshop
Get PDFEmpirical evidence suggests a correlation between motivation and reading achievement as well as a decline in motivation as students progress through the grades. In order to address this issue, it is necessary to determine the instructional methods that promote motivation and identity development in reading. This study examines the motivation and the identity development of four fourth grade students as they experienced the reading workshop over the course of one year. Ford’s Motivational Systems Theory and Wenger’s Theory of Learning frame the study of student motivation and identity development within the reading workshop. Data related to motivation and identity development was collected weekly through student interviews, surveys, and conferences. A description of the context was gained through researcher observations and a teacher interview. Analysis of this data revealed that (1) Increased time spent reading self- selected books correlates positively to student motivation and identity development. (2) Increased responsive feedback from teachers and peers is correlated with increased motivation and reading identity development. (3) These elements form the crux of the reading workshop, which supports the notion that this model of instruction encourages motivation and identity development. (4) The correlation between motivation, identity development, and achievement is not evident in the context of this study. However, this correlation often emerges over time. This dissertation concludes with directions for future research, which may contribute to a further understanding of the relationship between student motivation, identity development and the reading workshop
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