Filled pauses are widely considered as a relatively consistent feature of an individual’s speech. However, acoustic consistency has only been observed within single-session recordings. By comparing... Show moreFilled pauses are widely considered as a relatively consistent feature of an individual’s speech. However, acoustic consistency has only been observed within single-session recordings. By comparing filled pauses in two recordings made >2.5 years apart, this study investigates within-speaker consistency of the vowels in the filled pauses uh and um, in both first language (L1) Dutch and second language (L2) English, produced by student speakers who are known to converge in other speech features. Results show that despite minor within-speaker differences between languages, the spectral characteristics of filled pauses in L1 and L2 remained stable over time. Show less
Westdijk, J.; Metz, B.; Spruit, N.; Tilstra, W.; Gun, J. van der; Hendriksen, C.; Kersten, G.F.A. 2017
Tomography is an imaging technique for reconstructing an object from projection images. Projection images are obtained by a scanner consisting of a radiation source and a detector. Due to... Show moreTomography is an imaging technique for reconstructing an object from projection images. Projection images are obtained by a scanner consisting of a radiation source and a detector. Due to imperfections in the scanner setup, measurement errors are introduced in the projections, which lead to errors in the reconstructed image. In this thesis we developed several techniques to make reconstruction algorithms more robust to these imperfections, such that errors in the projection data have a smaller effect on the reconstruction. We consider errors caused by: misalignment, low radiation dose, unknown background intensities and nonlinearities in the projection acquisition. The key concept that is used for correcting errors is consistency optimization of the projection data and the reconstruction. By using a forward projection model, projections from a reconstruction can be simulated. If the model (and the reconstruction) is accurate the simulated projections match the observed projections. Consistency is therefore a measure which we can use to estimate parameters of the model. For example, misalignment can be corrected for by introducing geometric parameters for the position of the detector and perturbations in the projection angles. Once the parameters correspond to the experiment the consistency is maximized and reconstruction errors are reduced. Show less
This research deals with investigating consistency of data across three altmetrics providers or aggregators: Altmetric.com, Mendeley and the Open Source software Lagotto (used by PLOS, CrossRef... Show moreThis research deals with investigating consistency of data across three altmetrics providers or aggregators: Altmetric.com, Mendeley and the Open Source software Lagotto (used by PLOS, CrossRef and others). The aim of this study is to explore if metrics for a same set of publications are consistent across them and if not, what are possible reasons that explain these differences. By consistency we mean having (reasonably) the same score for the same DOI per source across different altmetrics providers/aggregators. For a proper development of the altmetric research and practice, it is critical to understand any potential similarity or difference in metrics across different altmetric aggregators. For this purpose, a random sample of 30,000 Crossref (15,000) and WoS (15,000) DOIs from 2013 has been considered. The data collection has been done at the same date/time on July 23 2015 starting at 2 PM CEST using the Mendeley REST API, Altmetric.com dump file and the Lagotto open source application. Similar sources and metrics across these 3 providers have been analyzed and compared (Facebook, Twitter, Mendeley, CiteULike and Reddit). Show less
The studies in this thesis concentrate on memory for an emotional event, with a specific focus on completeness, consistency and accuracy of emotional memories and their predictors. In doing so,... Show moreThe studies in this thesis concentrate on memory for an emotional event, with a specific focus on completeness, consistency and accuracy of emotional memories and their predictors. In doing so, both field and laboratory studies were conducted. The results show that overall, memory for emotional events is fairly complete and consistent over time. Still, the human memory is sometimes incomplete and prone to inaccuracies and inconsistencies. Maybe an elephant never forgets, people occasionally do! Emotional state, psychiatric status and psychological variables, with the exception of (peri) traumatic dissociation, did not have a strong influence on completeness, consistency and accuracy of memory for emotional events. Show less
