Information-theoretic measures as a generic approach to human-robot interaction : Application in CORBYS project

Permission to make digital or hard copies of part or all of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the first page. Copyrights for third-party components of this work must be honored. For all other uses, contact the Owner/AuthorThe objective of the CORBYS project is to design and implement a robot control architecture that allows the integration of high-level cognitive control modules, such as a semantically-driven self-awareness module and a cognitive framework for anticipation of, and synergy with, human behaviour based on biologically-inspired information-theoretic principles. CORBYS aims to provide a generic control architecture to benefit a wide range of applications where robots work in synergy with humans, ranging from mobile robots such as robotic followers to gait rehabilitation robots. The behaviour of the two demonstrators, used for validating this architecture, will each be driven by a combination of task specific algorithms and generic cognitive algorithms. In this paper we focus on the generic algorithms based on information theoryFinal Accepted Versio

The Removal of Artificially Generated Polarization in SHARP Maps

We characterize the problem of artificial polarization for the Submillimeter High Angular Resolution Polarimeter (SHARP) through the use of simulated data and observations made at the Caltech Submillimeter Observatory (CSO). These erroneous, artificial polarization signals are introduced into the data through misalignments in the bolometer sub-arrays plus pointing drifts present during the data-taking procedure. An algorithm is outlined here to address this problem and correct for it, provided that one can measure the degree of the sub-array misalignments and telescope pointing drifts. Tests involving simulated sources of Gaussian intensity profile indicate that the level of introduced artificial polarization is highly dependent upon the angular size of the source. Despite this, the correction algorithm is effective at removing up to 60% of the artificial polarization during these tests. The analysis of Jupiter data taken in January 2006 and February 2007 indicates a mean polarization of 1.44%+/-0.04% and 0.95%+/-0.09%, respectively. The application of the correction algorithm yields mean reductions in the polarization of approximately 0.15% and 0.03% for the 2006 and 2007 data sets, respectively.Comment: 19 pages, 7 figure

Extrasolar Asteroid Mining as Forensic Evidence for Extraterrestrial Intelligence

The development of civilisations like ours into spacefaring, multi-planet entities requires significant raw materials to construct vehicles and habitats. Interplanetary debris, including asteroids and comets, may provide such a source of raw materials. In this article we present the hypothesis that extraterrestrial intelligences (ETIs) engaged in asteroid mining may be detectable from Earth. Considering the detected disc of debris around Vega as a template, we explore the observational signatures of targeted asteroid mining (TAM), such as unexplained deficits in chemical species, changes in the size distribution of debris and other thermal signatures which may be detectable in the spectral energy distribution (SED) of a debris disc. We find that individual observational signatures of asteroid mining can be explained by natural phenomena, and as such they cannot provide conclusive detections of ETIs. But, it may be the case that several signatures appearing in the same system will prove harder to model without extraterrestrial involvement. Therefore signatures of TAM are not detections of ETI in their own right, but as part of "piggy-back" studies carried out in tandem with conventional debris disc research, they could provide a means of identifying unusual candidate systems for further study using other SETI techniques.Comment: 15 pages, 2 figures, accepted for publication in the International Journal of Astrobiolog

Modeling working memory: An interference model of complex span

This article introduces a new computational model for the complex-span task, the most popular task for studying working memory. SOB-CS is a two-layer neural network that associates distributed item representations with distributed, overlapping position markers. Memory capacity limits are explained by interference from a superposition of associations. Concurrent processing interferes with memory through involuntary encoding of distractors. Free time in-between distractors is used to remove irrelevant representations, thereby reducing interference. The model accounts for benchmark findings in four areas: (1) effects of processing pace, processing difficulty, and number of processing steps; (2) effects of serial position and error patterns; (3) effects of different kinds of item-distractor similarity; and (4) correlations between span tasks. The model makes several new predictions in these areas, which were confirmed experimentall

"Chest Pain Typicality" in Suspected Acute Coronary Syndromes and the Impact of Clinical Experience

BACKGROUND: Physicians rely upon chest pain history to make management decisions in patients with suspected acute coronary syndromes, particularly where the diagnosis is not immediately apparent through ECG and troponin testing. OBJECTIVE: To establish the discriminatory value of 'typicality of chest pain' and the effect of clinician experience, for the prediction of acute myocardial infarction and presence of significant coronary artery disease. METHODS: Prospective single-center observational study undertaken in a U.K. General Hospital emergency department. We recruited consecutive adults with chest pain and a non-diagnostic ECG, for whom the treating physician determined delayed troponin testing was necessary. Using their own clinical judgment, physicians recorded whether the chest pain described was typical or atypical for acute coronary syndrome. Physicians were defined as "experienced" or "novice" according to postgraduate experience. Acute myocardial infarction was adjudicated using a high-sensitivity troponin (hs-cTn) assay, while coronary artery disease was adjudicated angiographically. RESULTS: Overall, 912 patients had typicality of chest pain assessed, of whom 114/912 (12.5%) had an acute myocardial infarction and 157/912 (17.2%) underwent angiography. In patients undergoing angiography, 90/157 (57.3%) had hs-cTn elevation, of whom 60 (66.7%) had significant coronary artery disease. 67/157 (42.7%) patients had angiography without hs-cTn elevation, of these 31 (46.2%) had significant coronary artery disease. For the diagnosis of acute myocardial infarction, chest pain typicality had an area under the curve (AUC) of 0.54 (95%CI 0.49-0.60). For the prediction of significant coronary artery disease with hs-cTn elevation AUC: 0.54 (0.40-0.67), and without hs-cTn elevation AUC: 0.45 (0.31-0.59). When assessed by experienced physicians, specificity for the diagnosis of acute myocardial infarction was higher at 65.8% (63.1%-68.7%) vs. 55.4% (53.9%-56.8%) for novices. CONCLUSIONS: Subjective interpretation of 'typicality of chest pain' is of limited discriminatory value in the assessment of suspected acute coronary syndromes, in the context of a non-diagnostic ECG. Greater clinical experience improves accuracy as a rule-in tool but does not improve overall discriminatory ability

Detection of FeO towards SgrB2

We have observed the J=5-4 ground state transition of FeO at a frequency of 153 GHz towards a selection of galactic sources. Towards the galactic center source SgrB2, we see weak absorption at approximately the velocity of other features towards this source (62 km s$^{-1}$ LSR). Towards other sources, the results were negative as they were also for MgOH(3-2) and FeC(6-5). We tentatively conclude that the absorption seen toward SgrB2 is due to FeO in the hot ($\sim$ 500 K) relatively low density absorbing gas known to be present in this line of sight. This is the first (albeit tentative) detection of FeO or any iron--containing molecule in the interstellar gas. Assuming the observed absorption to be due to FeO, we estimate [FeO]/[SiO] to be of order or less than 0.002 and [FeO]/[H$_{2}$] of order $3 10^{-11}$. This is compatible with our negative results in other sources. Our results suggest that the iron liberated from grains in the shocks associated with SgrB2 remains atomic and is not processed into molecular form.Comment: 1 postscrit figure,10 page

What are the most effective behaviour change techniques to promote physical activity and/or reduce sedentary behaviour in inactive adults? : A systematic review protocol

This is an Open Access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/ The version of record, Howlett N, Trivedi D, Troop NA, et al, 'What are the most effective behaviour change techniques to promote physical activity and/or reduce sedentary behaviour in inactive adults? A systematic review protocol', BMJ Open, Vol 5(8), 2015; 5:e008573, is available online via doi: 10.1136/bmjopen-2015-008573 Published by MBJ Publishing Group Limited.Large proportions of the population are not meeting recommended levels of physical activity and have increasingly sedentary lifestyles. Low levels of physical activity are predictive of poor health outcomes and time spent sedentary is related to a host of risk factors independently of physical activity levels. Building an evidence base of the best approaches to intervene in the lifestyles of inactive individuals is crucial in preventing long-term disease, disability and higher mortality ratesPeer reviewedFinal Published versio

A test of interference versus decay in working memory:Varying distraction within lists in a complex span task

We tested two competing explanations of the effect of processing on working memory. According to decay models, memory representations decay during processing and can be rehearsed or refreshed in the free time between processing steps. Alternatively, one interference-based model assumes that processing involves encoding of distractor representations in working memory, and free time is used to remove distractors. In several experiments the demand from distractor processing was varied within lists, such that one burst of processing following an item on the list was either particularly demanding or particularly undemanding. The exceptional distractor burst had its greatest effect on the list item that immediately preceded it (a local effect), and it affected items that had not yet been presented as well as preceding items. Both findings are predicted by a computational interference model of working memory, and together are problematic for the viewpoint that refreshing offsets decay.</p

Relationship between Diffusion, Selfdiffusion and Viscosity

We investigate the experimental limits of validity of the Stokes-Einstein equation. There is an important difference between diffusion and self-diffusion. There are experimental evidences, that in the case of self-diffusion the product D /T is constant and the equation is still valid. However, comparison of existing experimental data on viscosity and diffusion coefficients D of small, fast moving ions unambiguously show that the product D /T depends strongly on temperature T. The temperature dependence of diffusion coefficient declines from that of viscosity. Therefore, the Stokes-Einstein equation is not valid in this case