User evaluation of an interactive learning framework for single-arm and dual-arm robots

The final publication is available at link.springer.comSocial robots are expected to adapt to their users and, like their human counterparts, learn from the interaction. In our previous work, we proposed an interactive learning framework that enables a user to intervene and modify a segment of the robot arm trajectory. The framework uses gesture teleoperation and reinforcement learning to learn new motions. In the current work, we compared the user experience with the proposed framework implemented on the single-arm and dual-arm Barrett’s 7-DOF WAM robots equipped with a Microsoft Kinect camera for user tracking and gesture recognition. User performance and workload were measured in a series of trials with two groups of 6 participants using two robot settings in different order for counterbalancing. The experimental results showed that, for the same task, users required less time and produced shorter robot trajectories with the single-arm robot than with the dual-arm robot. The results also showed that the users who performed the task with the single-arm robot first experienced considerably less workload in performing the task with the dual-arm robot while achieving a higher task success rate in a shorter time.Peer ReviewedPostprint (author's final draft

Transient Cenozoic tectonic stages in the southern margin of the Caribbean plate : U-Th/He thermochronological constraints from Eocene plutonic rocks in the Santa Marta massif and Serranía de Jarara, northern Colombia

We use U-Th/(He) zircon and apatite thermochronology and Al in hornblende geobarometry from Eocene granitoids of the Sierra Nevada de Santa Marta and Guajira uplifted massifs in northern Colombia to elucidate the exhumation history of the northern South America continental margin and its bearing to Cenozoic Caribbean- South American plate interactions. Aluminium in hornblende geobarometry from the Eocene Santa Marta batholith yields pressures between 4.9±0.6kbar and 6.4±0.6kbar, which indicate that at least, 14.7-19.2km of unroofing took place since 56-50Ma in the northwestern Sierra Nevada de Santa Marta. In the Guajira Peninsula, calculated pressures for the Eocene Parashi stock are 2.3±0.6kbar and 3±0.6kbar. Stratigraphic considerations pertaining to Oligocene conglomerates from the Guajira area suggest that 6.9-9km of crust was lost between 50Ma and ca. 26Ma. U-Th/He zircon and apatite thermochronology from granitoids in the Sierra Nevada de Santa Marta shows the existence of major exhumation events in the Late Eocene (ca. 45-40Ma), Late Oligocene (ca. 25Ma) and Miocene (ca. 15Ma). The Guajira region records the Late Eocene to Early Oligocene (35-25Ma) event, but it lacks evidence for the Miocene exhumation phase. These differences reflect isolation of the Guajira region from the Sierra Nevada de Santa Marta and the Andean chain due to extensive block rotation and transtensional tectonics that affected the region during post-Eocene times. The post-Eocene events correlate in time with an increased convergence rate and the frontal approach of North and South America. It is suggested that the two major tectonic mechanisms that govern exhumation in these Caribbean massifs are: 1) subduction of the Caribbean plate, and 2) post Eocene changes in plate convergence obliquity and rates that caused the South American continental margin blocks to override the Caribbean plate. Temporal correlation with other Caribbean and Northern Andean events allows to resolve the regional Cenozoic plate tectonic reorganizations experienced by the South American, Caribbean and Pacific plates at a regional scale

Diabetes Mellitus in a Patient With Lafora Disease: Possible Links With Pancreatic β-Cell Dysfunction and Insulin Resistance

Lafora disease (LD) is a rare autosomal recessive disorder characterized by progressive myoclonic epilepsy followed by continuous neurological decline, culminating in death within 10 years. LD leads to accumulation of insoluble, abnormal, glycogen–like structures called Lafora bodies (LBs). It is caused by mutations in the gene encoding glycogen phosphatase (EPM2A) or the E3 ubiquitin ligase malin (EPM2B/NHLRC1). These two proteins are involved in an intricate, however, incompletely elucidated pathway governing glycogen metabolism. The formation of EPM2A and malin signaling complex promotes the ubiquitination of proteins participating in glycogen metabolism, where dysfunctional mutations lead to the formation of LBs. Herein, we describe a 13-years-old child with LD due to a NHLRC1 (c.386C > A, p.Pro129His) mutation, who has developed diabetes mellitus and was treated with metformin. We discuss how basic mechanisms of LD could be linked to β-cell dysfunction and insulin resistance

A Novel and More Efficient Way to Grind Punching Tools

ABSTRACT A simulation model of punch grinding has been developed which calculates the instantaneous material-removal rate, arc length of contact and temperature based on the kinematic relationships between wheel and workiece and determines the optimum machine parameters to reduce cycle time and achieve a constant-temperature no-burn situation. Two basic outputs of the simulation model include arc length of contact and specific material-removal rate. A thermal model is included in the simulation to calculate maximum grinding zone temperature rise. A novel method is developed to constrain this temperature rise in the simulation. The thermal model inputs a constant value of specific grinding energy and the energy partition, which represents the fraction of the grinding energy conducted as heat to the workpiece. The simulation-based optimization can lead to a drastic reduction of grinding cycle time. Moreover, the limitation of maximum grinding zone temperature rise below the transitional temperature can help to avoid generation of workpiece thermal damage, which includes thermal softening, residual tensile stress, and rehardening burn. The grindability of high speed steel (HSS) is also discussed in terms of power consumption, specific grinding energy and undeformed chip thickness

Benchmarks for the Forward Observables at RHIC, the Tevatron-run II and the LHC

We present predictions on the total cross sections and on the ratio of the real part to the imaginary part of the elastic amplitude (rho parameter) for present and future pp and pbar p colliders, and on total cross sections for gamma p -> hadrons at cosmic-ray energies and for gamma gamma-> hadrons up to sqrt{s}=1 TeV. These predictions are based on an extensive study of possible analytic parametrisations invoking the biggest hadronic dataset available at t=0. The uncertainties on total cross sections, including the systematic errors due to contradictory data points from FNAL, can reach 1.9% at RHIC, 3.1% at the Tevatron, and 4.8% at the LHC, whereas those on the rho parameter are respectively 5.4%, 5.2%, and 5.4%.Comment: 11 pages, 2 figures, 4 tables, RevTeX

Transdisciplinarity: towards an epistemology of what matters

This chapter explores the adoption of a transdisciplinary approach to knowledge by a doctor of professional studies research programme at Middlesex University in London. This programme is designed for senior professionals in a range of sectors who wish to bring about change, of varying degrees of magnitude, in practices and attitudes in their contexts. Its research pedagogy combines professional and academic knowledge to meet challenges posed by the temporal limitations of rapidly shifting local and global contexts. It proposes that conceptualising practice, through a transdisciplinary lens, opens up significant possibilities for both articulating and navigating the complexities inherent in any cultural ecology and the positioning of the researcher in that context. This enhances the research process’s potency to influence attitudes, focus and impact including the concept of agential knowing in identifying and attending to what matters

How can the Odderon be detected at RHIC and LHC

The Odderon remains an elusive object, 33 years after its invention. The Odderon is now a fundamental object in QCD and CGC and it has to be found experimentally if QCD and CGC are right. In the present paper, we show how to find it at RHIC and LHC. The most spectacular signature of the Odderon is the predicted difference between the differential cross-sections for proton-proton and antiproton-proton at high s and moderate t. The experiment can be done by using the STAR detector at RHIC and by combining these future data with the already present UA4/2 data. The Odderon could also be found by ATLAS exeperiment at LHC by performing a high-precision measurement of the real part of the hadron elastic scattering amplitude at small t.Comment: 14 pages, 16 figures, two typographical errors corrected and acknowledgments adde

P-P Total Cross Sections at VHE from Accelerator Data

Comparison of P-P total cross-sections estimations at very high energies - from accelerators and cosmic rays - shows a disagreement amounting to more than 10 %, a discrepancy which is beyond statistical errors. Here we use a phenomenological model based on the Multiple-Diffraction approach to successfully describe data at accelerator energies. The predictions of the model are compared with data On the basis of regression analysis we determine confident error bands, analyzing the sensitivity of our predictions to the employed data for extrapolation. : using data at 546 and 1.8 TeV, our extrapolations for p-p total cross-sections are only compatible with the Akeno cosmic ray data, predicting a slower rise with energy than other cosmic ray results and other extrapolation methods. We discuss our results within the context of constraints in the light of future accelerator and cosmic ray experimental results.Comment: 26 pages aqnd 11 figure

Odderon in Gauge/String Duality

At high energies, elastic hadronic cross sections, such as $pp, \overline p p, \pi^{\pm} p$, are dominated by vacuum exchange, which in leading order of the $1/N_c$ expansion has been identified as the BFKL Pomeron or its strong AdS dual the closed string Reggeized graviton \cite{Brower:2006ea}. However the difference of particle anti-particle cross sections are given by a so-called Odderon, carrying C = -1 vacuum quantum numbers identified in weak coupling with odd numbers of exchanged gluons. Here we show that in the dual description the Odderon is the Reggeized Kalb-Ramond field ($B_{\mu\nu}$) in the Neveu-Schwartz sector of closed string theory. To first order in strong coupling, the high energy contribution of Odderon is evaluated for ${\cal N} = 4$ Super Yang-Mills by a generalization of the gravity dual analysis for Pomeron in Ref. \cite{Brower:2006ea}. The consequence of confinement on the Odderon are estimated in the confining QCD-like $AdS^5$ hardwall model of Polchinski and Strassler \cite{Polchinski:2001tt}.Comment: 69 pages, 6 figures. Title change to better reflect the content of the paper. More discussion added in the Comments section. To be published in JHE