378 research outputs found
Music composition in the 21st Century: exploring concertgoersā aesthetic response to AI-generated music.
Masters degree. University of KwaZulu-Natal, Durban.We live in the information age where digitisation and computational technology have become integral
and indispensable to our daily activities. Artificial intelligence (AI), quantum computing, and other such
technologies increasingly impact and disrupt our lives as we connect with our world. Within the arts, a
field once dominated by human creation, we now experience a penetration of AI and deep learning
technologies. The researcher, a practising musician, became interested in how our ubiquitous
interaction with AI technology affects our decision-making and how it relates specifically to the field of
music composition. The manifestation of AIās impact on music-making was met with the researcherās
excitement and trepidation. Given the researcherās apprehension, he proposed investigating (1) the
quality of AI creativity in the field of music composition and (2) how transparency of this AI creative
employment affects aesthetic judgement. He designed his research using a mixed methods approach,
comprising a quantitative phase in the form of an online questionnaire (based on the original
AESTHEMOS instrument), followed by a qualitative phase of in-depth interviews. The researcherās
objectives were twofold: (1) to establish if a sample of concertgoers could discern aesthetically between
compositions generated by humans and AI and (2) how knowledge of AI use during the compositional
process affects our aesthetic appreciation of the artefacts. The researcher partly hypothesised that
participants could not discern aesthetically between human and AI-generated compositions because of
current available AI technology (through machine and deep learning). However, when AI employment is
disclosed, aesthetic responses to compositions yield a negative response. To test his hypothesis, the
researcher engaged thirty concertgoers in Amsterdam, The Netherlands, to evaluate aesthetically five
symphonic works via an online questionnaire. During the follow-up interview process, the AI generation
of two of the five compositions was disclosed, and general attitudes toward AI creativity was probed.
Using data analytic tools such as the Mann-Whitney U test, the researcher confirmed his hypothesis
and concluded that participants interact aesthetically with AI-generated compositions if they appear to
be human-composed. Transparency of AI involvement, however, affects the aesthetic value of AIgenerated
compositions. As AI weaves itself deeper into the human story, the familiarity of AI creativity
will profoundly affect our notion of creativity, meaning and art creation of the future
Correction for respiration artifact in pulmonary blood pressure signals of ventilated patients
Objective. To develop an algorithm that corrects pulmonary artery pressure signals of ventilated patients for the respiration artifact. The algorithm should test the validity of the pulmonary pressure signal and differentiate between the cyclic respiration artifact and true measurement artifacts. Methods. The shape of each pulmonary pressure beat is described by eight characteristic features, including mean pressure value and the systolic and diastolic timing and pressure values. The features are corrected for the respiration artifact by fitting them in a least-squares sense on the first and second harmonica of the ventilator frequency. The corrected features are used by a signal validation algorithm, which adds a validity flag to each pressure beat. The validation algorithm rejects pressure beats with sudden changes in their shape but adapts itself when the changes persist. Results. The performance of the correction and validation technique was evaluated using pulmonary artery pressure signals of 30 patients who were scheduled for open heart surgery. The algorithm correctly recognized as invalid data those pressure signals disturbed by coagulation, surgical manipulations, or flushes of the pressure line. The algorithm marked on average 77 Ā± 11 % of the pulmonary pressure beats as valid. Conclusions. The validation algorithm marked sufficient pressure beats as valid to update a trend display every 5 sec. The correction algorithm enabled the validation algorithm to differentiate between true measurement artifacts and the respiration artifact
Selective feature preserved elastic surface registration in complex geometric morphology
Deforming a complex generic shape into a representation of another complex shape is investigated. An initial study is done on the effect of cranial shape variation on masticatory induced stress. A finite element analysis is performed on two different skull geometries. One skull geometry has a prognathic shape, characterised by jaws protruding forward, while the other has a non-prognathic form. Comparing the results of the initial nite element analyses, the effect of an undesired variation in shape and topology on the resulting stress field is observed. This variation in shape and topology can not be attributed to the cranial shape variation that is investigated. This means that the variation in the masticatory induced stress field that is due to the relative degree in prognathism can not be quantified effectively. To best compare results, it would be beneficial to have a computational domain for the different skull geometries that have one-to-one correspondence. An approach to obtain a computational domain that represents various geometries with the exact same mesh size and connectivity between them does exist. This approach involves deforming a generic mesh to represent different target shapes. This report covers an introductory study to register and deform a generic mesh to approximately represent a complex target geometry. Various procedures are investigated, implemented and combined to specifically accommodate complex geometries like that of the human skull. A surface registration procedure is implemented and combined with a feature registration procedure. Feature lines are extracted from the surface representation of each skull as well as the generic shape. These features are compared and an initial deformation is applied to the generic shape to better represent the corresponding features on the target. Selective feature preserved elastic surface registration is performed after the initial feature based registration. Only the registration to surfaces of featureless areas and matched feature areas are allowed along with user selected areas during surface registration. The implemented procedures have various aspects that still require improvement before the desired study regarding prognathism's effect on masticatory induced stress could truly be approached pragmatically. Focus is only given to the use of existing procedures while the additional required improvements could be addressed in future work. It is however required that the resulting discretised domain obtained in this initial study be of sufficient quality to be used in a finite element analysis (FEA). The implemented procedure is illustrated using the two original skull geometries. Symmetric versions of these geometries are generated with a one-to-one correspondence map between them. The skull representations are then used in a finite element analysis to illustrate the appeal of having computational domains with a consistent mapping between them. The variation in the masticatory induced stress field due to the variation in cranial shape is illustrated using the consistent mapping between the geometries as part of this example.Dissertation (MEng)--University of Pretoria, 2011.Mechanical and Aeronautical Engineeringunrestricte
An adequate strategy for the thermodilution technique in patients during mechanical ventilation
The application of the thermodilution method in conditions associated with variations in blood flow implies a misuse of the Stewart Hamilton equation. Therefore, we studied the reliability of the thermodilution method for the estimation of mean cardiac output (CO) during mechanical ventilation in patients (n=9). Variation of the injection moment in the ventilatory cycle elicited a cyclic variation of CO estimates. This variation was not the same for all patients neither in phase nor in amplitude. Therefore, no specific phase in the ventilatory cycle could be selected for an accurate estimation of mean CO. Averaging CO estimates randomly distributed in the ventilatory cycle led to an improvement of accuracy with the square root of the number of observations. The averaging of CO estimates spread equally over the ventilatory cycle led to a much better result, e.g., the variation in the average of two estimates equally spread in the ventilatory cycle was similar to the variation in the average of four random estimates. We conclude that averaging of 3 or 4 estimates spread equally over the ventilatory cycle is an adequate strategy to estimate mean cardiac output in patients reliably
The influence of conversational content on college studentsā safe sex intentions:A mixed method approach
Even though health campaign designers are advised to specifically focus on triggering conversations between people about health issues, there is still a lot unknown about what aspects of a conversation may contribute to safe sex behavior and intentions. Empirical research in this field so far has mainly focused on conversational occurrence rather than conversational content, and where content is taken into account, this mostly concerns self-reports. In this mixed method study, we looked into the quantitative effects of real-life conversations about safe sex, triggered by a safe sex message, on college studentsā intentions related to safe sex. We then used a qualitative analysis to try and identify content-related aspects that may be related to the quantitative effects. Two weeks after filling in a questionnaire on their safe sex-related intentions, participants (N = 24) were instructed to watch and talk about a safe sex video with a conversation partner of choice, followed by filling in a questionnaire. The conversational data were analyzed qualitatively. The results suggest that the conversations increased safe sex-related intentions compared to pretest scores, and that content-related aspects such as conversational valence, type of communication behavior and behavioral determinants were related to these effects. Thus, our findings provide enhanced insight into the social norms and behavioral patterns related to safe sex, and indicate that it is important to look at conversational content in detail rather than to focus on mere conversational occurrence or quantitative effects
Quality and denoising in real-time functional magnetic resonance imaging neurofeedback: A methods review
First published: 25 April 2020Neurofeedback training using real-time functional magnetic resonance imaging
(rtfMRI-NF) allows subjects voluntary control of localised and distributed brain activity.
It has sparked increased interest as a promising non-invasive treatment option in
neuropsychiatric and neurocognitive disorders, although its efficacy and clinical significance
are yet to be determined. In this work, we present the first extensive review
of acquisition, processing and quality control methods available to improve the quality
of the neurofeedback signal. Furthermore, we investigate the state of denoising
and quality control practices in 128 recently published rtfMRI-NF studies. We found:
(a) that less than a third of the studies reported implementing standard real-time
fMRI denoising steps, (b) significant room for improvement with regards to methods
reporting and (c) the need for methodological studies quantifying and comparing the
contribution of denoising steps to the neurofeedback signal quality. Advances in
rtfMRI-NF research depend on reproducibility of methods and results. Notably, a systematic
effort is needed to build up evidence that disentangles the various mechanisms
influencing neurofeedback effects. To this end, we recommend that future
rtfMRI-NF studies: (a) report implementation of a set of standard real-time fMRI denoising
steps according to a proposed COBIDAS-style checklist (https://osf.io/kjwhf/),
(b) ensure the quality of the neurofeedback signal by calculating and reporting
community-informed quality metrics and applying offline control checks and (c) strive
to adopt transparent principles in the form of methods and data sharing and support
of open-source rtfMRI-NF software. Code and data for reproducibility, as well as an
interactive environment to explore the study data, can be accessed at https://github.
com/jsheunis/quality-and-denoising-in-rtfmri-nf.LSHāTKI, Grant/Award Number: LSHM16053āSGF; Philips Researc
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