514 research outputs found

    Active Control for Object Perception and Exploration with a Robotic Hand

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    We present an investigation on active control for intelligent object exploration using touch with a robotic hand. First, uncertainty from the exploration is reduced by a probabilistic method based on the accumulation of evidence through the interaction with an object of interest. Second, an intrinsic motivation approach allows the robot hand to perform intelligent active control of movements to explore interesting locations of the object. Passive and active perception and exploration were implemented in simulated and real environments to compare their benefits in accuracy and reaction time. The validation of the proposed method were performed with an object recognition task, using a robotic platform composed by a three-fingered robotic hand and a robot table. The results demonstrate that our method permits the robotic hand to achieve high accuracy for object recognition with low impact on the reaction time required to perform the task. These benefits make our method suitable for perception and exploration in autonomous robotics

    Learning to Teach About Ideas and Evidence in Science : The Student Teacher as Change Agent

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    A collaborative curriculum development project was set up to address the lack of good examples of teaching about ideas and evidence and the nature of science encountered by student teachers training to teach in the age range 11-16 in schools in England. Student and teacher-mentor pairs devised, taught and evaluated novel lessons and approaches. The project design required increasing levels of critique through cycles of teaching, evaluation and revision of lessons. Data were gathered from interviews and students' reports to assess the impact of the project on student teachers and to what extent any influences survived when they gained their first teaching posts. A significant outcome was the perception of teaching shifting from the delivery of standard lessons in prescribed ways to endeavours demanding creativity and decision-making. Although school-based factors limited newly qualified teachers' chances to use new lessons and approaches and therefore act as change-agents in schools, the ability to critique curriculum materials and the recognition of the need to create space for professional dialogue were durable gains

    Inclusive Dielectron Cross Sections in p+p and p+d Interactions at Beam Energies from 1.04 to 4.88 GeV

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    Measurements of dielectron production in p+p and p+d collisions with beam kinetic energies from 1.04 to 4.88 GeV are presented. The differential cross section is presented as a function of invariant pair mass, transverse momentum, and rapidity. The shapes of the mass spectra and their evolution with beam energy provide information about the relative importance of the various dielectron production mechanisms in this energy regime. The p+d to p+p ratio of the dielectron yield is also presented as a function of invariant pair mass, transverse momentum, and rapidity. The shapes of the transverse momentum and rapidity spectra from the p+d and p+p systems are found to be similar to one another for each of the beam energies studied. The beam energy dependence of the integrated cross sections is also presented.Comment: 15 pages and 16 figure

    Equilibrium random-field Ising critical scattering in the antiferromagnet Fe(0.93)Zn(0.07)F2

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    It has long been believed that equilibrium random-field Ising model (RFIM) critical scattering studies are not feasible in dilute antiferromagnets close to and below Tc(H) because of severe non-equilibrium effects. The high magnetic concentration Ising antiferromagnet Fe(0.93)Zn(0.07)F2, however, does provide equilibrium behavior. We have employed scaling techniques to extract the universal equilibrium scattering line shape, critical exponents nu = 0.87 +- 0.07 and eta = 0.20 +- 0.05, and amplitude ratios of this RFIM system.Comment: 4 pages, 1 figure, minor revision

    How a spin-glass remembers. Memory and rejuvenation from intermittency data: an analysis of temperature shifts

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    The memory and rejuvenation aspects of intermittent heat transport are explored theoretically and by numerical simulation for Ising spin glasses with short-ranged interactions. The theoretical part develops a picture of non-equilibrium glassy dynamics recently introduced by the authors. Invoking the concept of marginal stability, this theory links irreversible `intermittent' events, or `quakes' to thermal fluctuations of record magnitude. The pivotal idea is that the largest energy barrier b(tw,T)b(t_w,T) surmounted prior to twt_w by thermal fluctuations at temperature TT determines the rate rq1/twr_q \propto 1/t_w of the intermittent events occurring near twt_w. The idea leads to a rate of intermittent events after a negative temperature shift given by rq1/tweffr_q \propto 1/t_w^{eff}, where the `effective age' twefftwt_w^{eff} \geq t_w has an algebraic dependence on twt_w, whose exponent contains the temperatures before and after the shift. The analytical expression is verified by numerical simulations. Marginal stability suggests that a positive temperature shift TTT \to T' could erase the memory of the barrier b(tw,T)b(t_w,T). The simulations show that the barrier b(tw,T)b(tw,T)b(t_w,T') \geq b(t_w,T) controls the intermittent dynamics, whose rate is hence rq1/twr_q \propto 1/t_w. Additional `rejuvenation' effects are also identified in the intermittency data for shifts of both signs.Comment: Revised introduction and discussion. Final version to appear in Journal of Statistical Mechanics: Theory and Experimen

    “Am I also going to die, doctor?” A systematic review of the impact of in-hospital patients witnessing a resuscitation of another patient

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    Background: There is a growing interest in the impact of family-witnessed resuscitation. However, evidence about the effect of hospitalised patients witnessing other patients' resuscitations is limited. Aim: The aim of this systematic review is to explore the existing evidence related to the impact on patients who witness resuscitation attempts on other patients in hospital settings. Methods: The databases BNI, CINAHL, EMBASE, MEDLINE and PsycINFO were searched with the terms 'patient', 'inpatient', 'resuscitation', 'CPR', 'cardiopulmonary resuscitation' and 'witness'. The search strategy excluded the terms 'out-of-hospital', 'family' and 'relative'. The inclusion criteria were: studies related to patients exposed to a resuscitation attempt performed on another patient; quantitative and qualitative design; and physiological or psychological outcome measures. No limitations of date, language or settings were applied. Results: Five of the 540 identified studies were included: two observational studies with control groups and three qualitative studies with interviews and focus groups. Articles were published between 1968 and 2006 and were mostly rated to have a low quality of evidence. Quantitative results of the observational studies showed an increased heart rate in the study group witnessing a resuscitation (p = 0.05), increased systolic blood pressure (p < 0.01) and increased anxiety (p < 0.01). The qualitative studies highlighted the coping strategies adopted by exposed patients in response to witnessing resuscitation, including denial and dissociation. Conclusions: Our findings suggest that patients may find witnessing resuscitation to be a stressful experience. However, the evidence is sparse and mainly of poor quality. Further research is needed in order to better understand the impacts of patients witnessing a resuscitation of another patient and to identify effective support systems. © European Society of Cardiology 2017
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