The Stellar Dynamics of Omega Centauri

The stellar dynamics of Omega Centauri are inferred from the radial velocities of 469 stars measured with CORAVEL (Mayor et al. 1997). Rather than fit the data to a family of models, we generate estimates of all dynamical functions nonparametrically, by direct operation on the data. The cluster is assumed to be oblate and edge-on but mass is not assumed to follow light. The mean motions are consistent with axisymmetry but the rotation is not cylindrical. The peak rotational velocity is 7.9 km/s at 11 pc from the center. The apparent rotation of Omega Centauri is attributable in part to its proper motion. We reconstruct the stellar velocity ellipsoid as a function of position, assuming isotropy in the meridional plane. We find no significant evidence for a difference between the velocity dispersions parallel and perpendicular to the meridional plane. The mass distribution inferred from the kinematics is slightly more extended than, though not strongly inconsistent with, the luminosity distribution. We also derive the two-integral distribution function f(E,Lz) implied by the velocity data.Comment: 25 Latex pages, 12 Postscript figures, uses aastex, epsf.sty. Submitted to The Astronomical Journal, December 199

Detection of Planetary Transits Across a Sun-like Star

We report high precision, high cadence photometric measurements of the star HD 209458, which is known from radial velocity measurements to have a planetary mass companion in a close orbit. We detect two separate transit events at times that are consistent with the radial velocity measurements. In both cases, the detailed shape of the transit curve due to both the limb darkening of the star and the finite size of the planet is clearly evident. Assuming stellar parameters of 1.1 R_Sun and 1.1 M_Sun, we find that the data are best interpreted as a gas giant with a radius of 1.27 +/- 0.02 R_Jup in an orbit with an inclination of 87.1 +/- 0.2 degrees. We present values for the planetary surface gravity, escape velocity, and average density, and discuss the numerous observations that are warranted now that a planet is known to transit the disk of its parent star.Comment: 10 pages, 3 figures, accepted by ApJ Letter

A Hedonic Analysis of the Value of Parks and Green Spaces in the Dublin Area [on housing market]. ESRI WP331. November 2009

We use a hedonic house price model to estimate the value of green spaces and parks to homeowners in the Dublin area. Using a dataset of house sales between 2001 and 2006 and combining it with available data on the location of green spaces in Dublin it is possible to assess the different values assigned to green areas by homeowners. We find that the value of green space depends first of all on how far from the property it is located. We also find a difference in the values assigned to open access parks and green spaces. For every 10% increase in the share of green space and park area near a house, its average price increases by 7% to 9%. We also attempted to identify different individual parks and rank them according to their value, however due to spatial multicollinearity the results were mixed

Efficient Methods for Calculating Sample Entropy in Time Series Data Analysis

Recently, different algorithms have been suggested to improve Sample Entropy (SE) performance. Although new methods for calculating SE have been proposed, so far improving the efficiency (computational time) of SE calculation methods has not been considered. This research shows such an analysis of calculating a correlation between Electroencephalogram(EEG) and Heart Rate Variability(HRV) based on their SE values. Our results indicate that the parsimonious outcome of SE calculation can be achieved by exploiting a new method of SE implementation. In addition, it is found that the electrical activity in the frontal lobe of the brain appears to be correlated with the HRV in a time domain.Peer reviewe

Inclusive Intelligent Learning Management System Framework - Application of Data Science in Inclusive Education

Dissertation presented as the partial requirement for obtaining a Master's degree in Data Science and Advanced Analytics, specialization in Data ScienceBeing a disabled student the author faced higher education with a handicap which as experience studying during COVID 19 confinement periods matched the findings in recent research about the importance of digital accessibility through more e-learning intensive academic experiences. Narrative and systematic literature reviews enabled providing context in World Health Organization’s International Classification of Functioning, Disability and Health, legal and standards framework and information technology and communication state-of-the art. Assessing Portuguese higher education institutions’ web sites alerted to the fact that only outlying institutions implemented near perfect, accessibility-wise, websites. Therefore a gap was identified in how accessible the Portuguese higher education websites are, the needs of all students, including those with disabilities, and even the accessibility minimum legal requirements for digital products and the services provided by public or publicly funded organizations. Having identified a problem in society and exploring the scientific base of knowledge for context and state of the art was a first stage in the Design Science Research methodology, to which followed development and validation cycles of an Inclusive Intelligent Learning Management System Framework. The framework blends various Data Science study fields contributions with accessibility guidelines compliant interface design and content upload accessibility compliance assessment. Validation was provided by a focus group whose inputs were considered for the version presented in this dissertation. Not being the purpose of the research to deliver a complete implementation of the framework and lacking consistent data to put all the modules interacting with each other, the most relevant modules were tested with open data as proof of concept. The rigor cycle of DSR started with the inclusion of the previous thesis on Atlântica University Institute Scientific Repository and is to be completed with the publication of this thesis and the already started PhD’s findings in relevant journals and conferences

Espacios madrileños de memoria: aplicación de las nuevas tecnologías a la imagen

Actas de las Primeras Jornadas Imagen, Cultura y Tecnología celebradas del 1 al 5 de julio de 2002 en la Universidad Carlos III de Madri

Inclusive Intelligent Learning Management System Framework

Machado, D. S-M., & Santos, V. (2023). Inclusive Intelligent Learning Management System Framework. International Journal of Automation and Smart Technology, 13(1), [2423]. https://doi.org/10.5875/ausmt.v13i1.2423The article finds context and the current state of the art in a systematic literature review on intelligent systems employing PRISMA Methodology which is complemented with narrative literature review on disabilities, digital accessibility and legal and standards context. The main conclusion from this review was the existing gap between the available knowledge, standards, and law and what is put into practice in higher education institutions in Portugal. Design Science Research Methodology was applied to output an Inclusive Intelligent Learning Management System Framework aiming to help higher education professors to share accessible pedagogic content and deliver on-line and presential classes with a high level of accessibility for students with different types of disabilities, assessing the uploaded content with Web content Accessibility Guidelines 3.0, clustering students according to their profile, conscient feedback and emotional assessment during content consumption, applying predictive models and signaling students at risk of failing classes according to study habits and finally applying a recommender system. The framework was validated by a focus group to which experts in digital accessibility, information systems and a disabled PhD graduate.publishersversionpublishe

The fickleness of data: Estimating the effects of different aspects of acupuncture treatment on heart rate variability (HRV). Initial findings from three pilot studies

© 2014 Tony Steffert and David Mayor.Heart rate variability (HRV) is a measure of the interplay between sympathetic and parasympathetic influences on heart rate. Higher HRV is usually associated with relaxation and health benefits, lower HRV with stress/pathology. HRV is used increasingly in acupuncture research. Electroacupuncture (EA) and transcutaneous electrical acupoint stimulation(TEAS) are frequently used variants of manual acupuncture (MA).Peer reviewe

Does the cortical response to electroacupuncture depend on stimulation frequency? Results of a pilot EEG study first proposed at the AACP Conference in 2001

© 2013 Tony Steffert and David Mayor.EEG (electroencephalography) is a low-cost, accessible method of investigating electrical brain activity that is sensitive to rapid changes (unlike fMRI). Electroacupuncture (EA) and Transcutaneous Electrical Acupoint Stimulation (TEAS) are methods of acupuncture-like stimulation. This pilot crossover study, first proposed at the 2001 AACP Conference,1,2 explores the relationship between frequency of TEAS applied peripherally and frequencies of cortical electrical activity detected centrally.Peer reviewe

Expectation and experience of the ‘nonspecific’ effects of acupuncture: Developing and piloting a set of questionnaires

© 2013 David Mayor and Tony Steffert.32-item ‘EXPectation of feelings’ questionnaires were developed to explore the expected (EXPre) and reported (EXPost) incidence of ‘nonspecific’ (whole person) feelings in response to acupuncture-type interventions, in particular electroacupuncture (EA) and transcutaneous electrical acupoint stimulation (TEAS). They were tested on 204 participants familiar with acupuncture in three separate cohorts (Pilot, CPD, Students). Their validity and reliability were assessed, a cluster analysis conducted, and the association between expectation and experience analysed, along with those items most frequently found, association with other trait and state measures, and the influence of various aspects of treatments on reported feelings. Results are briefly reported in our poster. Methods and further detailed material are provided in the online background information.Peer reviewedFinal Published versio