7,264 research outputs found

    Iterative Path Optimisation for Personalised Dressing Assistance using Vision and Force Information

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    We propose an online iterative path optimisation method to enable a Baxter humanoid robot to assist human users to dress. The robot searches for the optimal personalised dressing path using vision and force sensor information: vision information is used to recognise the human pose and model the movement space of upper-body joints; force sensor information is used for the robot to detect external force resistance and to locally adjust its motion. We propose a new stochastic path optimisation method based on adaptive moment estimation. We first compare the proposed method with other path optimisation algorithms on synthetic data. Experimental results show that the performance of the method achieves the smallest error with fewer iterations and less computation time. We also evaluate real-world data by enabling the Baxter robot to assist real human users with their dressing

    An intersection-movement-based stochastic dynamic user optimal route choice model for assessing network performance

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    Different from traditional methods, this paper formulates the logit-based stochastic dynamic user optimal (SDUO) route choice problem as a fixed point (FP) problem in terms of intersection movement choice probabilities, which contain travelers’ route information so that the realistic effects of physical queues can be captured in the formulation when a physical-queue traffic flow model is adopted, and that route enumeration and column generation heuristics can be avoided in the solution procedure when efficient path sets are used. The choice probability can be either destination specific or origin–destination specific, resulting into two formulations. To capture the effect of physical queues in these FP formulations, the link transmission model is modified for the network loading and travel time determination. The self-regulated averaging method (SRAM) was adopted to solve the FP formulations. Numerical examples were developed to illustrate the properties of the problem and the effectiveness of the solution method. The proposed models were further used to evaluate the effect of information quality and road network improvement on the network performance in terms of total system travel time (TSTT) and the cost of total vehicle emissions (CTVE). Numerical results show that providing better information quality, enhancing link outflow capacity, or constructing a new road can lead to poor network performance.postprin

    Morphology, Temperature, and Field Dependence of Charge Separation in High-Efficiency Solar Cells Based on Alternating Polyquinoxaline Copolymer

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    Charge separation and recombination are key processes determining the performance of organic optoelectronic devices. Here we combine photoluminescence and photovoltaic characterisation of organic solar cell devices with ultrafast multi-pulse photocurrent spectroscopy to investigate charge generation mechanisms in the organic photovoltaic devices based on a blend of an alternating polyquinoxaline copolymer with fullerene. The combined use of these techniques enables the determination of the contributions of geminate and bimolecular processes to the solar cell performance. We observe that charge separation is not a temperature-activated process in the studied materials. At the same time, the generation of free charges shows a clear external-field and morphology dependence. This indicates that the critical step of charge separation involves the non-equilibrium state that is formed at early times after photoexcitation, when the polaronic localisation is not yet complete. This work reveals new aspects of molecular level charge dynamics in the organic light-conversion systems.We thank Maxim Pschenichnikov for useful discussions, and Ergang Wang for providing TQ1. This work was supported by the Netherlands Organization for Scientific Research (NWO) through the “Stichting voor Fundamenteel Onderzoek der Materie” (FOM). A.A.B. also acknowledges a VENI grant from NWO. A.A.B. is currently a Royal Society University Research Fellow. Photovoltaics research at Linköping was supported by the Swedish Research Council (VR), the European Commission Marie Skłodowska-Curie actions, the Swedish Energy Agency, and the Knut and Alice Wallenberg foundation (KAW).This is the author accepted manuscript. The final version is available from the American Chemical Society via http://dx.doi.org/10.1021/acs.jpcc.5b1080

    The color of smiling: computational synaesthesia of facial expressions

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    This note gives a preliminary account of the transcoding or rechanneling problem between different stimuli as it is of interest for the natural interaction or affective computing fields. By the consideration of a simple example, namely the color response of an affective lamp to a sensed facial expression, we frame the problem within an information- theoretic perspective. A full justification in terms of the Information Bottleneck principle promotes a latent affective space, hitherto surmised as an appealing and intuitive solution, as a suitable mediator between the different stimuli.Comment: Submitted to: 18th International Conference on Image Analysis and Processing (ICIAP 2015), 7-11 September 2015, Genova, Ital

    Novel SNPs polymorphism of bovine CACNA2D1 gene and their association with somatic cell score

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    Mastitis is a major cause of economic loss in dairy cattle. In this study, the bovine CACNA2D1 gene was taken as a candidate gene for mastitis resistance. The objective of this study was to identify single nucleotide polymorphisms (SNPs) in the bovine CACNA2D1 gene and evaluate the association of these SNPs with mastitis in cattle. Through DNA sequencing and PCR-RFLP analysis, three mutations C367400T, A496561G and G519663A were detected in the cattle CACNA2D1 gene. Altogether 240 dairy cattle of three breeds (Holstein, Simmental, and Sanhe cattle) were genotyped and allele frequencies were determined. The effects of CACNA2D1 polymorphisms on somatic cell score (SCS) were analyzed and a significant association was found between G519663A and SCS. The mean of genotype GG was significantly lower than those of genotypes AG and AA. The results of this research will be useful in further studies to determine the role of the CACNA2D1 gene in mastitis resistance and further work will be necessary to investigate whether the CACNA2D1 gene play a role in defending the host from mastitis.Key words: Association analysis, CACNA2D1 gene, dairy breeds, mastitis, somatic cell score

    Evolution of Wurtzite Structured GaAs Shells Around InAs Nanowire Cores

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    GaAs was radially deposited on InAs nanowires by metal–organic chemical vapor deposition and resultant nanowire heterostructures were characterized by detailed electron microscopy investigations. The GaAs shells have been grown in wurtzite structure, epitaxially on the wurtzite structured InAs nanowire cores. The fundamental reason of structural evolution in terms of material nucleation and interfacial structure is given

    Polarization and temperature dependence of photoluminescence from zincblende and wurtzite InP nanowires

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    We use polarization-resolved and temperature-dependent photoluminescence of single zincblende (ZB) (cubic) and wurtzite (WZ) (hexagonal) InPnanowires to probe differences in selection rules and bandgaps between these two semiconductor nanostructures. The WZ nanowires exhibit a bandgap80meV higher in energy than the ZB nanowires. The temperature dependence of the PL is similar but not identical for the WZ and ZB nanowires. We find that ZB nanowires exhibit strong polarization parallel to the nanowire axis, while the WZ nanowires exhibit polarized emission perpendicular to the nanowire axis. This behavior is interpreted in terms of the different selection rules for WZ and ZB crystal structures.A.M., L.V.T., T.B.H., H.E.J., L.M.S., and J.M.Y.-R. acknowledge support from the Institute for Nanoscale Science and Technology of the University of Cincinnati and the National Science Foundation through Grant Nos. EEC/NUE 0532495 and ECCS 0701703. The Australian authors acknowledge support from the Australian Research Council. Y.K. acknowledges support by the Korean Science and Engineering Foundation KOSEF through Grant No. F01- 2007-000-10087-0
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