On the force feedback control of a manipulator with a compliant wrist force sensorÜber die druckrückführungs-steuerung eines manipulators mit einem nachgiebigen handgelenk-drucksensor

The force feedback algorithm is presented for the manipulator which consists of a high stiffness position servo system with six-degree of freedom and has a compliant six-component force sensor at its wrist. The obtained algorithm has the following three features. First, this algorithm gives the relation between the position and orientation of the wrist at the present step and that of the wrist to be attained at the next step. Second, an efficient calculation method to obtain each joint movement satisfying this relation is proposed. Third, this algorithm reduces the force feedback control to the position feedback control of each joint in case the force sensor is sufficiently compliant compared with its environment.     

Comparison of Eysenck's PEN and Lanyon's Psychological Screening Inventory in a group of American students.

Administered Eysenck's Psychoticism, Extraversion, and Neuroticism Inventory and the Psychological Screening Inventory (PSI) to 178 male and 297 female undergraduates. Included in the study was an 18-item Lie scale taken from the Eysenck Personality Inventory. A factorial analysis of the intercorrelations showed that 3 major factors could account for the bulk of correlations among the 9 differently labeled characteristics covered by the 2 inventories. These 3 factors were identified as Psychological Disturbance, Extraversion, and Defensiveness, respectively. The 1st factor was characterized by alienation, psychoticism, discomfort, and neuroticism. The 2nd factor was mainly identified by high loadings on Eysenck's Extraversion and the PSI Expression scales. The Defensiveness factor was mainly marked by the Lie scale and the PSI Defensiveness scale. The PSI Social Nonconformity scale loaded equally moderately on both the Psychological Disturbance and Defensiveness factors for both male and female groups. In the case of the male group, its highest loading was on the Extraversion factor. (16 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interactions between PVC Geomembranes and Compacted Clays

The interactions between plastic soils and polyvinyl chloride (PVC) geomembranes were studied using a direct shear device under as-compacted conditions. The PVC geomembranes had smooth or textured surfaces, and the soils were of plasticity index (PI) ranging from 35 to 100%. The peak and residual failure envelopes were expressed using Coulomb failure criteria. The adhesion and angle of friction increased for PIs up to 70% and subsequently recorded a decrease. The adhesion is larger for the peak strength compared to the residual strength, but it was the reverse for the angle of friction. The efficiency in terms of adhesion appeared more relevant than that of the angle of friction in expressing the interactions between geomembrane and cohesive soils. The smooth and textured geomembranes showed little difference in results at the residual state.     

Identification of cholesta-7,24-dien-3β-ol and desmosterol in hamster cauda epididymal spermatozoa

The sterol composition of hamster cauda epididymal spermatozoa was remarkably different from that of several other mammalian spermatozoa. Desmosterol and cholesta-7,24-dien-3β-ol account for as much as 90% of the total sterols. Cholesterol and desmosterol are the major components of mouse cauda epididymal spermatozoa, and rabbit, boar and bull ejaculated spermatozoa. Cholesta-7,24-dien-3β-ol was not detected. Furthermore, cholesterol was the main sterol in hamster caput epididymal spermatozoa, while only a trace amount of desmosterol was detected and cholesta-7,24-dien-3β-ol was hardly detected at all. The sterol content of cauda and caput epididymal spermatozoa was 0.17±0.05 μmol/10⁸ spermatozoa. During maturation, the desmosterol and cholesta-7,24-dien-3β-ol levels increase and the cholesterol level decreases. Cholesta-7,24-dien-3β-ol appears as a sterol in mature spermatozoa and seems to be a characteristic sterol of hamster cauda epididymal spermatozoa.     

Generalization bounds for non-stationary mixing processes

This paper presents the first generalization bounds for time series prediction with a non-stationary mixing stochastic process. We prove Rademacher complexity learning bounds for both average-path generalization with non-stationary \(\beta \)-mixing processes and path-dependent generalization with non-stationary \(\phi \)-mixing processes. Our guarantees are expressed in terms of \(\beta \)- or \(\phi \)-mixing coefficients and a natural measure of discrepancy between training and target distributions. They admit as special cases previous Rademacher complexity bounds for non-i.i.d. stationary distributions, for independent but not identically distributed random variables, or for the i.i.d. case. We show that, using a new sub-sample selection technique we introduce, our bounds can be tightened under the natural assumption of asymptotically stationary stochastic processes. We also prove that fast learning rates can be achieved by extending existing local Rademacher complexity analyses to the non-i.i.d. setting. We conclude the paper by providing generalization bounds for learning with unbounded losses and non-i.i.d. data.     

Lateral post-buckling analysis of thin-walled open section beams

Thin-walled beams with open sections are studied using a nonlinear model. This model is developed in the context of large displacements and small deformations, by accounting for bending-bending and bending-torsion couplings. The warping and shortening effects are considered in the torsion equilibrium equation. The governing coupled equilibrium equations obtained from Galerkin’s method are solved by a Newton–Raphson iterative process. It is established that the buckling loads are highly dependent on the pre-buckling deformations of the beam. The bifurcated branches are unstable and strongly influenced by shortening effects. Some comparisons are presented with the solutions commonly used in linear stability, like in the standard European steel code (Eurocode 3). The regular solutions appear to be very conservative, especially for I sections with large flanges.