Precise computer controlled positioning of robot end effectors using force sensors

A major problem in space applications of robotics and docking of spacecraft is the development of technology for automated precise positioning of mating components with smooth motion and soft contact. To achieve the above objective, a design method was developed for optimally placing the closed-loop poles of a discretized robotic control system at exact prescribed locations inside the unit circle of the complex z-plane. The design method combines the merits of the pole placement and the linear quadratic design approaches. The proposed design procedure is based on the assignment of one real eigenvalue or two complex conjugate (or real) eigenvalues at each design step. The method involves solutions of simple algebraic equations and this is considered to be efficient for on-line or off-line computations. Also, two methods for the linearization of the nonlinear model of a robotic manipulator were presented. Since automatic control of multi-degree freedom robotic manipulators involves high nonlinear equations of systems, a pilot project was proposed involving the control of a one-dimensional system. This simple system can be readily implemented for testing the concepts and algorithms

An introduction to the interim digital SAR processor and the characteristics of the associated Seasat SAR imagery

Basic engineering data regarding the Interim Digital SAR Processor (IDP) and the digitally correlated Seasat synthetic aperature radar (SAR) imagery are presented. The correlation function and IDP hardware/software configuration are described, and a preliminary performance assessment presented. The geometric and radiometric characteristics, with special emphasis on those peculiar to the IDP produced imagery, are described

Fish fights over fish rights: Conflicts arising from re-allocation of fishing lots: perceptions from community fisheries in Cambodia

Disputes, Aquaculture, Cambodia,

Benchmarking the Performance of Time-Dependent Density Functional Methods

The performance of 24 density functionals, including 14 meta-generalized gradient approximation (mGGA) functionals, is assessed for the calculation of vertical excitation energies against an experimental benchmark set comprising 14 small- to medium-sized compounds with 101 total excited states. The experimental benchmark set consists of singlet, triplet, valence, and Rydbergexcited states. The global-hybrid (GH) version of the Perdew-Burke-Ernzerhoff GGA density functional (PBE0) is found to offer the best overall performance with a mean absolute error (MAE) of 0.28 eV. The GH-mGGA Minnesota 2006 density functional with 54% Hartree-Fock exchange (M06-2X) gives a lower MAE of 0.26 eV, but this functional encounters some convergence problems in the ground state. The local density approximation functional consisting of the Slater exchange and Volk-Wilk-Nusair correlation functional (SVWN) outperformed all non-GH GGAs tested. The best pure density functional performance is obtained with the local version of the Minnesota 2006 mGGA density functional (M06-L) with an MAE of 0.41 eV

Prédiction sélective des traitements pour le suivi d'objet

International audienceL'un des problèmes majeurs du suivi d'objet en vidéo est la dérive, c'est-à-dire la mauvaise localisation à un instant donné d'une entité désignée dans une image initiale. Les nombreux algorithmes de suivi visuel ou trackers sont tous susceptibles de dériver lorsqu'ils sont confrontés à diverses sources de nuisance (occultations, changements d'apparence ou d'illumination, mouvements irréguliers de la cible et de la caméra...) mais sont également caracté-risés par des niveaux de robustesse variés à ces phéno-mènes. L'approche proposée par notre travail est de s'ins-pirer d'une caractéristique de la vision naturelle, l'atten-tion visuelle, considérée ici comme un ensemble de mé-canismes prédictifs de sélection de l'information ou des ressources. Dans le problème étudié, son rôle est alors de combiner dynamiquement les trackers selon leur capacité à assurer globalement le suivi à partir de mesures d'auto-évaluation en ligne de leur comportement et de leur adé-quation au contexte. L'effort est porté sur la combinaison de trackers hétérogènes en coût de calcul et en structure fonctionnelle, et sur la capacité de les munir générique-ment de telles fonctions d'auto-évaluation. Mots Clef attention visuelle, vision par ordinateur, suivi d'objet, pré-diction de dérives, fusion Abstract One of the key problems in video object tracking is drift, this is the bad localization of an entity initially appointed in an image at a given moment. The numerous visual tracking algorithms or trackers are all likely to drift when they are confronted with diverse sources of disturbances (occlusions, appearance changes or illuminations, irregular movements of the target and the camera) but are also characterized by different levels of robustness in response to these phenomena. The approach proposed by our work is inspired by a characteristic of natural vision, visual attention , considered here as a set of predictive mechanisms of selection of the information or the resources. In the studied problem, its role is then to dynamically combine trackers according to their capacity to globally insure tracking from measures of on-line self-assessment of their behaviour and their adequacy to the context. In our combination of heterogeneous trackers, the efforts concern the cost of calculation , the functional structure, and the capacity to equip them generically with such self-assessment functions

A standardized transcutaneous electric acupoint stimulation for relieving tobacco urges in dependent smokers

The efficacy of acupuncture in smoking cessation, and its effect on the urge to smoke are unclear. We evaluated the effect of a standardized protocol of transcutaneous electric acupoint stimulations (TEAS) on alleviating the urge to smoke. Ninety-eight smokers were recruited in two double-blind studies. Participants abstained from smoking for 26 h, and were randomized to receive TEAS alternating between 2 and 100 Hz at four acupoints (LI4 and PC8, PC6 and TE5) at four different intensities (10, 5, Intermittent 5 or 0 mA). The urge to smoke was assessed by the Questionnaire of Smoking Urges (QSU-Brief). In Experiment 1, the 10 mA group (n = 20) was compared with the 5 mA group (n = 20); the increase in smoking urges did not differ significantly. Considering the possibility that 5 mA may be an active intervention, in Experiment 2, a true placebo (0 mA), and a proxy of placebo [Intermittent 5 mA (i5 mA)] were compared with 10 mA TEAS. In this experiment, 10 mA (n = 20) TEAS showed a tendency to alleviate smoking urges compared with 0 mA (n = 16), and i5 mA (n = 19) TEAS. Only when the data of smokers with Fagerstöm Test for Nicotine Dependence score ≥5 were analyzed that the difference between the 10 mA group and the control group (0 and i5 mA) became significant. Based on these preliminary findings, we conclude that TEAS applied on the skin may antagonize the increase in urge to smoke in abstinent-dependent smokers. It seems warranted to assess the efficacy of TEAS in smoking cessation clinical trials involving a larger population of dependent smokers

A Standardized Transcutaneous Electric Acupoint Stimulation for Relieving Tobacco Urges in Dependent Smokers

The efficacy of acupuncture in smoking cessation, and its effect on the urge to smoke are unclear. We evaluated the effect of a standardized protocol of transcutaneous electric acupoint stimulations (TEAS) on alleviating the urge to smoke. Ninety-eight smokers were recruited in two double-blind studies. Participants abstained from smoking for 26 h, and were randomized to receive TEAS alternating between 2 and 100 Hz at four acupoints (LI4 and PC8, PC6 and TE5) at four different intensities (10, 5, Intermittent 5 or 0 mA). The urge to smoke was assessed by the Questionnaire of Smoking Urges (QSU-Brief). In Experiment 1, the 10 mA group (n = 20) was compared with the 5 mA group (n = 20); the increase in smoking urges did not differ significantly. Considering the possibility that 5 mA may be an active intervention, in Experiment 2, a true placebo (0 mA), and a proxy of placebo [Intermittent 5 mA (i5 mA)] were compared with 10 mA TEAS. In this experiment, 10 mA (n = 20) TEAS showed a tendency to alleviate smoking urges compared with 0 mA (n = 16), and i5 mA (n = 19) TEAS. Only when the data of smokers with Fagerstöm Test for Nicotine Dependence score ≥5 were analyzed that the difference between the 10 mA group and the control group (0 and i5 mA) became significant. Based on these preliminary findings, we conclude that TEAS applied on the skin may antagonize the increase in urge to smoke in abstinent-dependent smokers. It seems warranted to assess the efficacy of TEAS in smoking cessation clinical trials involving a larger population of dependent smokers

Retrospective-Cost Adaptive Control of Uncertain Hammerstein-Wiener Systems with Memoryless and Hysteretic Nonlinearities

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/97108/1/AIAA2012-4449.pd