Bluetooth low energy for autonomous human-robot interaction

© 2017 Copyright held by the owner/author(s).This demonstration shows how inexpensive, off-the-shelf, and unobtrusive Bluetooth Low Energy (BLE) devices can be utilized for enabling robots to recognize touch gestures, to perceive proximity information, and to distinguish between interacting individuals autonomously. The received signal strength (RSS) between the BLE device attached to the robot and BLE devices attached to the interacting individuals is used to achieve this. Almost no software configuration is needed and the setup can be applied to most everyday environments and robot platforms

Bose-Einstein Condensation in a CO_2-laser Optical Dipole Trap

We report on the achieving of Bose-Einstein condensation of a dilute atomic gas based on trapping atoms in tightly confining CO_2-laser dipole potentials. Quantum degeneracy of rubidium atoms is reached by direct evaporative cooling in both crossed and single beam trapping geometries. At the heart of these all-optical condensation experiments is the ability to obtain high initial atomic densities in quasistatic dipole traps by laser cooling techniques. Finally, we demonstrate the formation of a condensate in a field insensitive m_F=0 spin projection only. This suppresses fluctuations of the chemical potential from stray magnetic fields.Comment: 8 pages, 5 figure

Persistência dos efeitos da escarificação sobre a compactação de Nitossolo sob plantio direto em região subtropical úmida.

Avalia a persistência dos efeitos da escarificação sobre a compactação de Nitossolo Vermelho, manejado sob plantio direto (PD), na região subtropical úmida do Brasil. O experimento foi realizado em blocos ao acaso, com quatro repetições e seis tratamentos, constituídos pelo tempo de manutenção do solo sob PD após escarificação: PD contínuo por 24 meses após escarificação, realizada setembro de 2009; PD contínuo por 18 meses após escarificação, realizada em março de 2010; PD contínuo por 12 meses após escarificação, realizada em setembro de 2010; PD contínuo por seis meses após escarificação, realizada em março de 2011; plantio realizado em solo recém escarificado, em setembro de 2011; e PD contínuo e sem escarificação (testemunha). As espécies cultivadas na área foram: milho, safra 2009/2010; trigo, em 2010; soja, safra 2010/2011; centeio, em 2011; e milho, safra 2011/2012. Os efeitos dos tratamentos foram avaliados a partir de parâmetros físicos do solo e de parâmetros morfológicos e produtivos da cultura do milho, na safra 2011/2012. A escarificação do Nitossolo sob plantio direto, em região de clima subtropical úmido, não aumenta a produtividade de grãos de milho, e os seus efeitos sobre a estrutura do solo não persistem por mais de 18 meses

Efeito de iscas tóxicas sobre o parasitoide Diachasmimorpha longicaudata (Hymenoptera: Braconidae).

O objetivo do trabalho foi avaliar o efeito de iscas tóxicas sobre o parasitoide D. longicaudata por meio de testes por ingestão

Spin Motion in Electron Transmission through Ultrathin Ferromagnetic Films Accessed by Photoelectron Spectroscopy

Ab initio and model calculations demonstrate that the spin motion of electrons transmitted through ferromagnetic films can be analyzed in detail by means of angle- and spin-resolved core-level photoelectron spectroscopy. The spin motion appears as precession of the photoelectron spin polarization around and as relaxation towards the magnetization direction. In a systematic study for ultrathin Fe films on Pd(001) we elucidate its dependence on the Fe film thickness and on the Fe electronic structure. In addition to elastic and inelastic scattering, the effect of band gaps on the spin motion is addressed in particular.Comment: 4 pages, 5 figure

Autonomous and Intrinsically Motivated Robots for Sustained Human-Robot Interaction

A challenge in using fully autonomous robots in human-robot interaction (HRI) is to design behavior that is engaging enough to encourage voluntary, long-term interaction, yet robust to the perturbations induced by human interaction. It has been repeatedly argued that intrinsic motivations (IMs) are crucial for human development, so it seems reasonable that this mechanism could produce an adaptive and developing robot, which is interesting to interact with. This thesis evaluates whether an intrinsically motivated robot can lead to sustained HRI. Recent research showed that robots which ‘appeared’ intrinsically motivated raised interest in the human interaction partner. The displayed IMs resulted from ‘unpredictably’ asking a question or from a self-disclosing statement. They were designed with the help of pre-defined scripts or teleoperation. An issue here is that this practice renders the behavior less robust toward unexpected input or requires a trained human in the loop. Instead, this thesis proposes a computational model of IM to realize fully autonomous and adaptive behavior generation in a robot. Previous work showed that predictive information maximization leads to playful, exploratory behavior in simulated robots that is robust to changes in the robot’s morphology and environment. This thesis demonstrates how to deploy the formalism on a physical robot that interacts with humans. The thesis conducted three within-subjects studies, where participants interacted with a fully autonomous Sphero BB8 robot with two behavioral regimes: one realizing an adaptive, intrinsically motivated behavior and the other being reactive, but not adaptive. The first study contributes to the idea of the overall proposed study design: the interaction needs to be designed in such a way, that participants are not given any idea of the robot’s task. The second study implements this idea, letting participants focus on answering the question of whether the robots are any different. It further contributes ideas for a more ‘challenging’ baseline behavior motivating the third and final study. Here, a systematic baseline is generated and shows that participants perceive it as almost indistinguishable and similarly animated compared to the intrinsically motivated robot. Despite the emphasis on the design of similarly perceived baseline behaviors, quantitative analyses of post-interaction questionnaires after each study showed a significantly higher perception of the dimension ‘Warmth’ for the intrinsically motivated robot compared to the baseline behavior. Warmth is considered a primary dimension for social attitude formation in social cognition. A human perceived as warm (i.e. friendly and trustworthy) experiences more positive social interactions. The Robotic Social Attribute Scale (RoSAS) implements the scale dimension Warmth for the HRI domain, which has been validated with a series of still images. Going beyond static images, this thesis provides support for the use and applicability of this scale dimension for the purpose of comparing behaviors. It shows that participants prefer to continue interacting with the robot they perceive highest in Warmth. This research opens new research avenues, in particular with respect to different physical robots and longitudinal studies, which are ought to be performed to corroborate the results presented here. However, this thesis shows the general methods presented here, which do not require a human operator in the loop, can be used to imbue robots with behavior leading to positive perception by their human interaction partners, which can yield sustained HRI

Clean thermal decomposition of tertiary-alkyl metal thiolates to metal sulfides: Environmentally-benign, non-polar inks for solution-processed chalcopyrite solar cells

We report the preparation of Cu2S, In2S3, CuInS2 and Cu(In,Ga)S2 semiconducting films via the spin coating and annealing of soluble tertiary-alkyl thiolate complexes. The thiolate compounds are readily prepared via the reaction of metal bases and tertiary-alkyl thiols. The thiolate complexes are soluble in common organic solvents and can be solution processed by spin coating to yield thin films. Upon thermal annealing in the range of 200-400 ??C, the tertiary-alkyl thiolates decompose cleanly to yield volatile dialkyl sulfides and metal sulfide films which are free of organic residue. Analysis of the reaction byproducts strongly suggests that the decomposition proceeds via an SN1 mechanism. The composition of the films can be controlled by adjusting the amount of each metal thiolate used in the precursor solution yielding bandgaps in the range of 1.2 to 3.3 eV. The films form functioning p-n junctions when deposited in contact with CdS films prepared by the same method. Functioning solar cells are observed when such p-n junctions are prepared on transparent conducting substrates and finished by depositing electrodes with appropriate work functions. This method enables the fabrication of metal chalcogenide films on a large scale via a simple and chemically clear process.ope

Sequential doping of solid chunks of a conjugated polymer for body-heat-powered thermoelectric modules

Sequential doping of 1 mm3 sized cubes of regio-regular poly(3-hexylthiophene) (P3HT) with 2,3,5,6-tetrafluoro-tetracyanoquinodimethane is found to result in a doping gradient. The dopant ingresses into the solid material and after two weeks of sequential doping yields a 250 μm thick doped surface layer, while the interior of the cubes remains undoped. The doping gradient is mapped with energy dispersive x-ray spectroscopy (EDX), which is used to estimate a diffusion coefficient of 1 7 10-10 cm2 s-1 at room temperature. The cubes, prepared by pressing at 150 \ub0C, feature alignment of polymer chains along the flow direction, which yields an electrical conductivity of 2.2 S cm-1 in the same direction. A 4-leg thermoelectric module was fabricated with slabs of pressed and doped P3HT, which generated a power of 0.22 μW for a temperature gradient of 10.2 \ub0C generated by body heat