On visual servoing based on efficient second order minimization

This paper deals with the Efficient Second order Minimization (ESM) and the image-based visual servoing schemes. In other words, it deals with the minimization based on the pseudo-inverse of the mean of the Jacobians or on the mean of Jacobian Pseudo-inverses. Chronologically, it has been noticed in Tahri and Chaumette (2003) [22] that ESM generally improves the system behavior when compared with the system in which only the simple Jacobian Pseudo-inverses are used. Subsequently, a mathematical explanation has been given in Malis (2004) [12]. In this paper, the proofs given by Malis are discussed and it will be shown that there is a limitation to the validity of the ESM. We will also show that the use of ESM does not necessarily ensure a better system behavior, especially in the situations where large rotational motions are involved. Further, a new appropriate formula of the ESM is proposed and validated using several kinds of features.     

Robust image-based visual servoing using invariant visual information

This paper deals with the use of invariant visual features for visual servoing. New features are proposed to control the 6 degrees of freedom of a robotic system with better linearizing properties and robustness to noise than the state of the art in image-based visual servoing. We show in this paper that by using these features the behavior of image-based visual servoing in task space can be significantly improved. Several experimental results are provided and validate our proposal.     

Involvement of trihydroxyconjugated bile salts in cholesterol assimilation by bifidobacteria

BACKGROUND: We assessed diurnal variation in the direction of mood switches in a sample of outpatients with rapid-cycling bipolar disorder who were on stable medication regimens. We predicted that patients would be more likely to switch from depression into mania or hypomania during the daytime hours and from mania/hypomania into depression overnight. METHOD: Fifteen patients with rapid-cycling bipolar disorder completed self-rated mood scales twice a day: once shortly after awakening and once at bedtime. Using 3 months of data for each patient, we performed categorical analyses (McNemar chi-square) to study the direction of mood switches between each day's morning and evening rating and between each evening rating and the subsequent morning rating. RESULTS: As predicted, switches that occurred between the morning and evening ratings were more likely to be from depression into mania/ hypomania or euthymia (64.3%) than in the opposite direction (35.6%; p < .0001). Similarly, switches that occurred between the evening rating and the next morning's ratings were more likely to be from mania/hypomania or euthymia into depression (64.8%) than in the opposite direction (35.2%; p < .0001). CONCLUSION: Extended wakefulness, exposure to light, increased activity, and/or endogenous rhythms could contribute to the elevation of mood during the course of the day. Sleep, darkness, reduced activity, and/or endogenous rhythms could contribute to the tendency to switch into depression overnight. Clinicians should attend to the time of day that clinical assessments are performed in patients with rapid-cycling bipolar disorder. Potential therapeutic implications include the use of light or activity during depression and use of induced sleep or exposure to darkness during mania/hypomania.     

Nouvelle expression temporelle de ľimpédance interne des conducteurs à section rectangulaire

In this paper, a new time domain internal impedance formula for characterizing the skin effect in interconnects of rectangular cross section is proposed. The comparison with the simulation results of a method involving frequency domain exact formula validates the present model and illustrates its accuracy. We have also shown the lack of precision of the formulations based on conductor losses varying as √ f In order to predict the responses of lossy planar transmission lines, the used methods are the time domain — frequency domain transformation (tdfd) and the finite difference time domain algorithm (fdtd). Theses techniques of analysis are applied to the mtl equations under quasi — tem approximation.     

Une méthode ďétude des lignes de transmission dans un milieu non homogène multicouche en présence ďun champ électromagnétique externe

A new simple time-domain method for simulating the coupling between an electromagnetic plane wave and a planar transmission line in a multilayered inhomogeneous medium is proposed. The approach is based upon the modified telegrapher’s equations. The originality of this approach comes from the fact that the calculation of the distributed sources takes into account the electromagnetic field in each layer. The calculation of this field in the multilayered medium is performed by means of the physical optic concept. A finite difference time domain (FDTD) algorithm is used to solve the transmission line equations. The comparison between our results and other theoretical and measured results validates the proposed simulation approach. It has also been demonstrated that neglecting the effect of inhomogeneous medium results in erroneous simulations.     

Classification of Honey According to Geographical and Botanical Origins and Detection of Its Adulteration Using Voltammetric Electronic Tongue

Main possible honey fraud is the addition of various sugar syrups. But, there are also other types of fraud, such as deception on the geographical and/or botanical origin product. Providing a product of the hive with full authenticity is therefore crucial for the preservation of beekeeping. In this pursuit, voltammetric electronic tongue (VE-tongue) was employed to classify honey samples from different geographical and botanical origins. Furthermore, VE-tongue was used to detect adulterants such as glucose syrup (GS) and saccharose syrup (SS) in honey. The data obtained were analyzed by three-pattern recognition techniques: principal component analysis (PCA), support vector machines (SVMs), and hierarchical cluster analysis (HCA). These methods enabled the classification of 18 honeys of different geographical origins and 7 honeys of different botanical origins. Excellent results were obtained also in the detection of adulterated honey. Therefore, this simple method based on VE-tongue could be useful in the honey packaging and commercialization industry.     

Remediation of hexavalent chromium by consortia of indigenous bacteria from tannery waste-contaminated biotopes in Fez,Morocco

Bioremediation is a promising, safe and economical technology widely used to clean up both soils and wastewaters containing Cr(VI). Most work uses pure microbial cultures. Little research has been done with mixed microbial cultures. In this study, consortia of indigenous bacteria isolated from a polluted site have been used to study the effect of different conditions such as Cr(VI) concentration, metal ions, electron donors and pH on Cr(VI) reduction by the consortia. We also evaluate the microbial ability to detoxify repeatedly and continuously in a non-modified medium. Results show that consortia of indigenous bacteria are resistant to greater than 200 mg/L Cr(VI). However, mixed cultures exhibited decreasing diversity with increasing levels of chromate. The consortia show high Cr(VI) removal capacity under various conditions and exhibit an ability for continuous reduction of Cr(VI) up to three consecutive inputs. The consortia may be appropriate for environmental applications for Cr(VI) remediation.     

Numerical simulation of the resistance braze welded assembly of a copper Inconel 601 ground electrode and a steel shell

Abstract

The ground electrode of spark plugs are assembled to a steel shell through a resistance braze-welding technique. Two types of currents can be used in that aim: AC or DC. Based on the current type, two different kinds of models were built. The first one is a 3-D magnetodynamic-thermal model, specially suited for AC current. The magnetodynamic and thermal FE analyses are weakly coupled to calculate the temperature distribution during the process. For the second model dedicated to DC currents, the temperature distribution during the process is obtained through a fully coupled 3-D electrokinetic-thermal modeling. The temperature distributions are then used to simulate the mechanical phenomena. The results of the different models are compared. The effects on the welded zone of the frequency (50 Hz and 5000 Hz), the regulation mode (current or voltage), and the spacing between copper and Inconel 601 coating are discussed.     

Analyse temporelle des lignes de transmission non uniformes avec effet de peau

This paper deals with a computational approach, based upon centered points finite-difference time-domain technique, for evaluating voltages and currents along nonuniform planar transmission lines terminated with arbitrary loads. To improve the accuracy of the method, the skin effect has been included into the algorithm by means of the approximation of the conductor internal impedance. Some configurations of nonuniform planar lines have been analyzed in order to show different aspects of the efficiency of this computational procedure.