3,388 research outputs found
Machines Learning - Towards a New Synthetic Autobiographical Memory
Autobiographical memory is the organisation of episodes and contextual information from an individual’s experiences into a coherent narrative, which is key to our sense of self. Formation and recall of autobiographical memories is essential for effective, adaptive behaviour in the world, providing contextual information necessary for planning actions and memory functions such as event reconstruction. A synthetic autobiographical memory system would endow intelligent robotic agents with many essential components of cognition through active compression and storage of historical sensorimotor data in an easily addressable manner. Current approaches neither fulfil these functional requirements, nor build upon recent understanding of predictive coding, deep learning, nor the neurobiology of memory. This position paper highlights desiderata for a modern implementation of synthetic autobiographical memory based on human episodic memory, and proposes that a recently developed model of hippocampal memory could be extended as a generalised model of autobiographical memory. Initial implementation will be targeted at social interaction, where current synthetic autobiographical memory systems have had success
Seismic hazard disaggregation in performance-based earthquake engineering: occurrence or exceedance?
VeloElectric: Creating a Device that Harvests Energy From Bicycles
Long distance mountain bikers, bike-packers, and many bikers in developing countries rely on electrical devices for safety and communication. These specific groups of people operate in areas with little to no electricity, and often times have no power to sustain their devices. The purpose of this Cal Poly senior project, VeloElectric, was to design, build, and test a kinetic energy harvester for bicycles that can be used to charge common mobile devices via USB. This senior project team created a device that attaches directly to a bicycle and uses vibrations to generate energy, which in turn powers a variety of portable devices. The final product will be used by Professor Lynne Slivovsky on a bike ride from Canada to Mexico. This document contains information on the entire project during the 2014-2015 school year. The “Background” section summarizes research and case studies including dynamo chargers and an electromagnetic induction charger called the nPower PEG. The Pedl team used this information to generate initial design ideas such as using piezoelectrics and other kinetic energy harvesting devices. This research was also used to gain a better understanding of the current state of art for this type of product. The end of the background section provides details of the project management plan that was used through the course of the projects focusing heavily on the tasks completed during Spring quarter. Following the “Background” section is an explanation of the development of conceptual designs that lead to the final product. Conceptual designs included decision matrices to decide on a 3D printed exterior casing, Velcro straps for attachment, electromagnetic induction for energy generation, and a battery for energy storage. Diagrams, models and pictures of the end product are displayed and analyzed in the “Description of Final Design” section. This section shows the exterior casing that was created to house the inner casing, battery, and printed circuit board. The “Product Realization” section focuses on how a lathe was used to create the final inner casing, 3D printing for the exterior casing and inner casing caps, and simple soldering for the electrical components. The section also explains how the final prototype cost the team about 45. The “Design Verification” section discusses how the final iteration was tested and includes test descriptions and photos while documenting the results of these tests. Example tests include weight, bike transfer time, USB compatibility, and vibrational tolerance. The document concludes by discussing the progress that was made on the project throughout the year and the recommendations that the design team has for possible future teams assigned to this task
Interactions of C+(2PJ) with rare gas atoms: incipient chemical interactions, potentials and transport coefficients
Accurate interatomic potentials were calculated for the interaction of a singly charged carbon cation, C+, with a single rare gas atom, RG (RG = Ne–Xe). The RCCSD(T) method and basis sets of quadruple-ζ and quintuple-ζ quality were employed; each interaction energy was counterpoise corrected and extrapolated to the basis set limit. The lowest C+(2P) electronic term of the carbon cation was considered, and the interatomic potentials calculated for the diatomic terms that arise from these: 2Πand 2Σ+. Additionally, the interatomic potentials for the respective spin-orbit levels were calculated, and the effect on the spectroscopic parameters was examined. In doing this, anomalously large spin-orbit splittings for RG = Ar–Xe were found, and this was investigated using multi-reference configuration interaction calculations. The latter indicated a small amount of RG → C+ electron transfer and this was used to rationalize the observations. This is taken as evidence of an incipient chemical interaction, which was also examined via contour plots, Birge–Sponer plots and various population analyses across the C+-RG series (RG = He–Xe), with the latter showing unexpected results. Trends in several spectroscopic parameters were examined as a function of the increasing atomic number of the RG atom. Finally, each set of RCCSD(T) potentials was employed, including spin-orbit coupling to calculate the transport coefficients for C+ in RG, and the results were compared with the limited available data
Mindfulness based cognitive therapy for young people and their carers: A mixed-methods feasibility study
This is the author accepted manuscript. The final version is available from Springer Verlag via the DOI in this record.We aimed to evaluate whether Mindfulness Based Cognitive Therapy (MBCT) was feasible and acceptable for
young people, their parents and the clinicians working with them; whether a parallel course for parents was a useful
addition; and whether attendance at MBCT was associated with improved outcomes. The design was a mixed
methods service evaluation of an eight session MBCT programme for young people who were recovering from
depression. The course was a manualised eight session group intervention. Both young people (n=18) and parents
(n=21) completed validated measures before and after the course. Semi-structured interviews were completed with
some group participants and clinical staff working in the service. Care records were searched for additional contact
following the intervention. Qualitative data from young people, parents and clinicians suggested that MBCT was
acceptable and feasible, and provided strategies to cope. The parent course was reported to provide personal support
to parents and helped them cope with their child’s depression while also impacting the family, promoted shared
understanding of depression and strategies to combat it, and addressed intergenerational aspects of depression. 84%
of participants attended at least 6/8 sessions and 48% required no further intervention within the following year.
Young people had statistically significant improvements across all outcome measures, while parents had statistically
significant improvements in rumination, self-compassion and decentering.Daniel Racey completed this work whilst supported by an NIHR Academic Clinical Fellowship while Kelly
Blockley and Vashti Berry are supported by the National Institute for Health Research (NIHR) Collaboration for Leadership in Applied Health Research and Care South West Peninsula
The bright optical afterglow of the nearby gamma-ray burst of 29 March 2003
Many past studies of cosmological gamma-ray bursts (GRBs) have been limited
because of the large distance to typical GRBs, resulting in faint afterglows.
There has long been a recognition that a nearby GRB would shed light on the
origin of these mysterious cosmic explosions, as well as the physics of their
fireballs. However, GRBs nearer than z=0.2 are extremely rare, with an
estimated rate of localisation of one every decade. Here, we report the
discovery of bright optical afterglow emission from GRB 030329. Our prompt
dissemination and the brilliance of the afterglow resulted in extensive
followup (more than 65 telescopes) from radio through X-ray bands, as well as
measurement of the redshift, z=0.169. The gamma-ray and afterglow properties of
GRB 030329 are similar to those of cosmological GRBs (after accounting for the
small distance), making this the nearest known cosmological GRB. Observations
have already securely identified the progenitor as a massive star that exploded
as a supernova, and we anticipate futher revelations of the GRB phenomenon from
studies of this source.Comment: 13 pages, 4 figures. Original tex
Effect of paper quality on the response rate to a postal survey: A randomised controlled trial. [ISRCTN32032031]
BACKGROUND: Response rates to surveys are declining and this threatens the validity and generalisability of their findings. We wanted to determine whether paper quality influences the response rate to postal surveys METHODS: A postal questionnaire was sent to all members of the British Society of Gynaecological Endoscopy (BSGE). Recipients were randomised to receiving the questionnaire printed on standard quality paper or high quality paper. RESULTS: The response rate for the recipients of high quality paper was 43/195 (22%) and 57/194 (29%) for standard quality paper (relative rate of response 0.75, 95% CI 0.33–1.05, p = 0.1 CONCLUSION: The use of high quality paper did not increase response rates to a questionnaire survey of gynaecologists affiliated to an endoscopic society
FMRI resting slow fluctuations correlate with the activity of fast cortico-cortical physiological connections
Recording of slow spontaneous fluctuations at rest using functional magnetic resonance imaging (fMRI) allows distinct long-range cortical networks to be identified. The neuronal basis of connectivity as assessed by resting-state fMRI still needs to be fully clarified, considering that these signals are an indirect measure of neuronal activity, reflecting slow local variations in de-oxyhaemoglobin concentration. Here, we combined fMRI with multifocal transcranial magnetic stimulation (TMS), a technique that allows the investigation of the causal neurophysiological interactions occurring in specific cortico-cortical connections. We investigated whether the physiological properties of parieto-frontal circuits mapped with short-latency multifocal TMS at rest may have some relationship with the resting-state fMRI measures of specific resting-state functional networks (RSNs). Results showed that the activity of fast cortico-cortical physiological interactions occurring in the millisecond range correlated selectively with the coupling of fMRI slow oscillations within the same cortical areas that form part of the dorsal attention network, i.e., the attention system believed to be involved in reorientation of attention. We conclude that resting-state fMRI ongoing slow fluctuations likely reflect the interaction of underlying physiological cortico-cortical connections
Multilevel Delayed Acceptance MCMC with an Adaptive Error Model in PyMC3
This is the final version. Available from NeurIPS 2020 via the DOI in this recordUncertainty Quantification through Markov Chain Monte Carlo (MCMC) can be prohibitively expensive for target probability densities with expensive likelihood functions, for instance when the evaluation it involves solving a Partial Differential Equation (PDE), as is the case in a wide range of engineering applications. Multilevel Delayed Acceptance (MLDA) with an Adaptive Error Model (AEM) is a novel approach, which alleviates this problem by exploiting a hierarchy of models, with increasing complexity and cost, and correcting the inexpensive models on-the-fly. The method has been integrated within the open-source probabilistic programming package PyMC3 and is available in the latest development version. In this paper, the algorithm is presented along with an illustrative example.Turing AI fellowshipEngineering and Physical Sciences Research Council (EPSRC
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