An algorithm for spectral factorization using random search techniques

An approximation method for the energy spectrum of a stationary stochastic dynamical system is presented, which allows approximate functional rational factorization.This paper is in three parts. The first deals with a theoretical problem of approximation in Hardy Spaces, whose main result is the following:Let S⁽ⁱⁿ⁾, S be positive functions belonging to L¹(R_gw), such that log S⁽ⁿ⁾ and log S belong to L¹(R_ω, dω/1 + ω²).Let h⁽ⁿ⁾, h be the outer functions of the Hardy Space H²(Π₊) such that S^(g) = |h⁽ⁿ⁾|² and S = |h|² on iR.If S⁽ⁿ⁾ n^→∝ S in L¹(R_ω), and log S⁽ⁿ⁾ n^→∝ log S in L¹(R_ω, dω/1 + ω²), then: h⁽ⁿ⁾ n^→∝ h in H²(Π₊).The second part describes an effective algorithm, using random search methods, and gives an almost sure convergence result for it.The third part treats numerically two examples, permitting comparison of this algorithm with others (whenever there are…): the first example is a problem of approximation for a nonrational process (turbulence) that was considered in Ref. 22: the second example is a problem of model reduction (automatic) considered in Ref. 4.     

Interhemispheric transfer after spontaneous recovery in 43 cases of severe closed head injury.

Examined the possibility of frequent callosal disconnection following closed head injury. Interhemispheric transfer was evaluated in 43 severe closed-head-injured patients (aged 18–51 yrs) using a wide-ranging battery of untimed behavioral tasks, after the period of spontaneous recovery. Only 1 S showed signs of callosal disconnection. Much effective interhemispheric transfer occurred in closed-head-injured Ss after the period of spontaneous recovery. More frequent occurrence of the disconnection syndrome in its acute phase is a possibility that cannot be excluded. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modeling of the Low-Frequency Noise in Thermal Lens Spectrometry

The low-frequency noise observed in thermal lens spectrometry (TLS) can be modeled by assuming that the heated region, constituted by the thermal lens gradient and associated convective stream, behaves as a weakly damped harmonic oscillator with a natural frequency, v_o, which is forced to move at an externally imposed pump frequency, v_p. Out-of-phase lower-frequency oscillations of the TLS signal can be produced both by transient events, such as the beginning of the TLS experiment and small changes in the pump beam stability, and by drift of boundary conditions, such as the temperature of the surroundings. A model is developed and checked using 1-(2-pyridylazo)-2-napthol (PAN) solutions in silicone oil. Consequences of analytical interest are drawn; e.g., the signal-to-noise ratio of the TLS experiments is improved by pumping at the resonance frequency, where v_p = v_o.     

Modelling and Characterizing a Screen-Printed Metallic Electrothermal Microactuator

A metallic electrothermal microactuator has been fabricated with screen-printing technology based on a sacrificial layer process. The actuator, printed on a standard 96% alumina, consists of two linked copper beams of different widths partially suspended above the substrate to which they are anchored. Energy-dispersive X-rays analyses demonstrate the harmlessness of the process with regard to the metallic layer. While increasing DC voltage between both anchors of the electrothermal microactuator, the deflection is optically measured using a calibrated CCD camera. The temperature distribution measured with an infrared camera in the actuator compares well with that calculated with finite element simulations.     

Concomitant use of liquid–liquid batch and continuous plug flow reactors for kinetic model discrimination. Application to the Rh/TPPTS catalysed reduction of the C–C double bond in dimethylitaconate

The biphasic catalytic reduction of the C–C double bond of dimethylitaconate with a water soluble rhodium/triphenylphosphinetrisulphonated sodium salt (TPPTS) complex is investigated. Kinetic studies in a well-mixed batch reactor provide kinetics parameters and an activation energy of 71 kJ mol⁻¹ but cannot discriminate between a first order or a complex kinetic model within the range of substrate concentration where the approximation of linear liquid/liquid partition is respected. Catalytic tests in the centrifugal partition chromatograph (CPC) reactor under steady-state operations in chemical regime and plug flow mode allow discriminating the kinetic models, the complex kinetic rate law being preferred.     

Conductometric biosensor based on glucose oxidase and beta-galactosidase for specific lactose determination in milk

This paper investigates the development of a biosensor associating two distinct enzymatic activities, that of the beta-galactosidase and that of the glucose oxidase, in order to apply it for the quantitative detection of lactose in milk. To eliminate interferences with glucose, a differential mode of measurement was used. Results show a linear calibration curve for lactose concentration between 60 and 800 μM (0.03 to 0.3 g/L). Tests with real commercial milk samples were carried out to validate the conductometric biosensor.     

Ionization of Acetylacetone in Me2SO—Water Mixtures. Reactivity—Selectivity Principle or Principle of Imperfect Synchronization?

Rate constants for the reversible deprotonation of acetylacetone were measured in carboxylate and amine buffers in water and in 50%, 90% and 95% Me₂SO at 20°C. The Brønsted plot for the carboxylate ions is curved in the Me₂SO—water mixtures, but straight in water. The curvature is in the direction predicted by the Reactivity—Selectivity Principle (RSP). However, the Brønsted plot for the reaction with primary amines is straight in all solvents. This suggests that the curvature observerd with the carboxylate ions is caused by loss of solvation of the base; this loss of solvation is ahead of bond formation in the transition state rather than being a manifestation of the RSP. (Note that all Brønsted plots are based on pK_a values measured in the respective solvents.) The intrinsic rate constant (k₀) for proton transfer increases with the addition of Me₂SO, and more so with the carboxylate buffers than with the amines. This increase in k₀ is attributed to delayed solvation of the developing enolate ion in the transition state; with the carboxylate buffers, an additional factor is the early loss of solvation of the base. The various solvation effects observed in this study can all be understood in the context of the Principle of Imperfect Synchronization (PIS).     

Générateur de machines séquentielles autotestables pour circuits intégrés spécifiques

This paper presents an original method using a ROM memory, of systematically synthesizing on-line and offline self-testing synchronous sequential machines (automata, sequencers,), for the design of compiled ASIC’S. Choices about state transition graph coding and circuit architecture are related to simplicity, compactness, operating rate and especially to testability. The on-line and off-line testing is based on an error detecting code of a recurrent type: in addition to useful data, the ROM memory contains redundant information which is distributed between two consecutive states. This method guarantees both present state coherence and past transition conformity. On-line testing is based in this type of coding, called distributed redundancy coding. Its fault coverage is given for different classes of hardware failures. Off-line testing, which is exhaustive, uses the distributed redundancy coding technique and consists in scanning all the possible graph transitions in memory address order.