2,303 research outputs found
Finding Meaning in the Two-Finger Banjo Style.
The two-finger banjo style languishes as a small footnote in the lexicon of old time banjo musicâvery important to a passionate (and lucky!) few, but not known by too many others. This research is a starting point to understanding the meaning of two-finger banjo; through a review of primary literature, interviews, witnessing performances, and individual investigation of playing two-finger banjo, I have been able to document some understandings about the style.
These understandings informed further appreciation of old time music, the old time music (and banjo) communities, and the art of making music in this wayâwhile describing the journey, I gained insights from scholars, folklorists, musicians, recordings, and made many discoveries that I documented in this thesis. I have concluded that one of the best ways to find meaning in any pursuit is by engaging with your community and connecting yourself to your art
How Useful are Educational Questions Generated by Large Language Models?
Controllable text generation (CTG) by large language models has a huge
potential to transform education for teachers and students alike. Specifically,
high quality and diverse question generation can dramatically reduce the load
on teachers and improve the quality of their educational content. Recent work
in this domain has made progress with generation, but fails to show that real
teachers judge the generated questions as sufficiently useful for the classroom
setting; or if instead the questions have errors and/or pedagogically unhelpful
content. We conduct a human evaluation with teachers to assess the quality and
usefulness of outputs from combining CTG and question taxonomies (Bloom's and a
difficulty taxonomy). The results demonstrate that the questions generated are
high quality and sufficiently useful, showing their promise for widespread use
in the classroom setting.Comment: Accepted to AIED Late Breaking Results 2023 - to be published in
their proceeding
Escape of the martian protoatmosphere and initial water inventory
Latest research in planet formation indicate that Mars formed within a few
million years (Myr) and remained a planetary embryo that never grew to a more
massive planet. It can also be expected from dynamical models, that most of
Mars' building blocks consisted of material that formed in orbital locations
just beyond the ice line which could have contained ~0.1-0.2 wt. % of H2O. By
using these constraints, we estimate the nebula-captured and catastrophically
outgassed volatile contents during the solidification of Mars' magma ocean and
apply a hydrodynamic upper atmosphere model for the study of the soft X-ray and
extreme ultraviolet (XUV) driven thermal escape of the martian protoatmosphere
during the early active epoch of the young Sun. The amount of gas that has been
captured from the protoplanetary disk into the planetary atmosphere is
calculated by solving the hydrostatic structure equations in the protoplanetary
nebula. Depending on nebular properties such as the dust grain depletion
factor, planetesimal accretion rates and luminosities, hydrogen envelopes with
masses >=3x10^{19} g to <=6.5x10^{22} g could have been captured from the
nebula around early Mars. Depending of the before mentioned parameters, due to
the planets low gravity and a solar XUV flux that was ~100 times stronger
compared to the present value, our results indicate that early Mars would have
lost its nebular captured hydrogen envelope after the nebula gas evaporated,
during a fast period of ~0.1-7.5 Myr. After the solidification of early Mars'
magma ocean, catastrophically outgassed volatiles with the amount of ~50-250
bar H2O and ~10-55 bar CO2 could have been lost during ~0.4-12 Myr, if the
impact related energy flux of large planetesimals and small embryos to the
planet's surface lasted long enough, that the steam atmosphere could have been
prevented from condensing. If this was not the case... (continued)Comment: 47 pages, 10 figures, 3 tables, submitted to PS
Turbulent Scalar Mixing in a Skewed Jet in Crossflow: Experiments and Modeling
Turbulent mixing of an inclined, skewed jet injected into a crossflow is investigated using MRI-based experiments and a high-fidelity LES of the same configuration. The MRI technique provides three-dimensional fields of mean velocity and mean jet concentration. The 30° skew of the jet relative to the crossflow produces a single dominant vortex which introduces spanwise asymmetries to the velocity and concentration fields. The turbulent scalar transport of the skewed jet is investigated in further detail using the LES, which is validated against the experimental measurements. Mixing is found to be highly anisotropic throughout the jet region. Isotropic turbulent diffusivity and viscosity are used to calculate an optimal value of the turbulent Schmidt number, which varies widely over the jet region and lies mostly outside of the typically accepted range 0.7 †Sct †0.9. Finally, three common scalar flux models of increasing complexity are evaluated based on their ability to capture the anisotropy and predict the scalar concentration field of the present configuration. The higher order models are shown to better represent the turbulent scalar flux vector, leading to more accurate calculations of the concentration field. While more complex models are better able to capture the turbulent mixing, optimization of model constants is shown to significantly affect the results
Validation of Immersed Boundary Simulations of Heart Valve Hemodynamics against In Vitro 4D Flow MRI Data
The immersed boundary (IB) method is a mathematical framework for
fluid-structure interaction problems (FSI) that was originally developed to
simulate flows around heart valves. Validation of FSI simulations around heart
valves against experimental data is challenging, however, due to the difficulty
of performing robust and effective simulations, the complications of modeling a
specific physical experiment, and the need to acquire experimental data that is
directly comparable to simulation data. In this work, we performed physical
experiments of flow through a pulmonary valve in an in vitro pulse duplicator,
and measured the corresponding velocity field using 4D flow MRI (4-dimensional
flow magnetic resonance imaging). We constructed a computer model of this
pulmonary artery setup, including modeling valve geometry and material
properties via a technique called design-based elasticity, and simulated flow
through it with the IB method. The simulated flow fields showed excellent
qualitative agreement with experiments, excellent agreement on integral
metrics, and reasonable relative error in the entire flow domain and on slices
of interest. These results validate our design-based valve model construction,
the IB solvers used and the immersed boundary method for flows around heart
valves
Making judgements about students making work : lecturersâ assessment practices in art and design.
This research study explores the assessment practices in two higher education art and design departments. The key aim of this research was to explore art and design studio assessment practices as lived by and experienced by art and design lecturers. This work draws on two bodies of pre existing research. Firstly this study adopted innovative methodological approaches that have been employed to good effect to explore assessment in text based subjects (think aloud) and moderation mark agreement (observation). Secondly the study builds on existing research into the assessment of creative practice. By applying thinking aloud methodologies into a creative practice assessment context the authors seek to illuminate the âin practiceâ rather than espoused assessment approaches adopted. The analysis suggests that lecturers in the study employed three macro conceptions of quality to support the judgement process. These were; the demonstration of significant learning over time, the demonstration of effective studentship and the presentation of meaningful art/design work
Cryopreserved homograft valves in the pulmonary position: Risk analysis for intermediate-term failure
AbstractObjective: The purpose of this study was to examine the durability of cryopreserved homografts used to replace the âpulmonaryâ valve and to identify factors associated with their late deterioration. Methods: We reviewed our entire experience (1985-1997) with 331 survivors in whom cryopreserved homograft valves (pulmonary, n = 304; aortic, n = 27) were used to reconstruct the pulmonary outflow tract. Median age was 14 years (range, 2 daysâ62 years). Operations included Ross operation (n = 259), tetralogy of Fallot (n = 41), truncus arteriosus (n = 14), Rastelli operation (n = 11), and others (n = 6). Median follow-up was 3.8 years (range, 0.2â11.2 years); late echographic follow-up was complete for 97% of patients. Homograft failure was defined as the need for explantation and valve-related death; homograft dysfunction was defined as a pulmonary insufficiency grade 3/4 or greater and a transvalvular gradient of 40 mm Hg or greater. Results: Homograft failure occurred in 9% (30 of 331 patients; Kaplan-Meier); freedom from failure was 82% ± 4% at 8 years. Homograft dysfunction occurred in 12% (39 of 331 patients), although freedom from dysfunction was 76% ± 4% at 8 years. For aortic homografts, this was 56% ± 11%, compared to 80% ± 4% for pulmonary homografts (P = .003). For patients aged less than 3 years (n = 38), this was 51% ± 12%, compared with 87% ± 4% for older patients (P = .0001). By multivariable analysis, younger age of homograft donors, non-Ross operation, and later year of operation were associated with homograft failure; younger age of homograft donors, later year of operation, and use of an aortic homograft were associated with homograft dysfunction. Conclusions: Homograft valves function satisfactorily in the pulmonary position at mid-term follow-up. The pulmonary homograft valve appears to be more durable than the aortic homograft valve in the pulmonary position. (J Thorac Cardiovasc Surg 1999;117:141-7
The stability of personality traits in adolescence and young adulthood
Models of economic decision-making usually assume that personality is stable over time. We assess the validity of this assumption over an eight-year time frame in adolescence and young adulthood using nationally representative panel data from Australia. Our study shows that unconditional mean-level changes in personality traits are smallâwith the exception of conscientiousness which increases by 0.38 SDâbecause most individuals do not change their scores in a statistically reliable way during adolescence and young adulthood, or changes occur in equal proportions in opposite directions. Controlling for systematic panel attrition and multiple hypothesis testing, we demonstrate that personality traits do not systematically respond to the majority of common one-off family-, income-, and health-related shocks. However, a small number of life eventsâmarriage, family members detained in jail, leaving the workforce and long-term health problemsâare associated with subsequent changes in personality. In particular, youth who experience long-term health problems including bodily pain increase their external locus of control by 0.5â0.9 SD, an economically meaningful change when expressed in terms of hourly wage penalty
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