The effect of pitch tracking on automatic dialect identification

Pitch tracking is one of the most important research topics in the recognition and identification area. This study concerns the effect of the pitch tracking technique used on the accuracy and speed of automatic dialect identification. This effort was carried out using the TIMIT database. The pitch tracking procedures investigated are the Boersma algorithm, the iterative adaptive inverse filtering approach, and the summation of residual harmonics method. All else being equal, the summation of residual harmonics provided the highest accuracy as well as the fastest performance of the three methods.     

An augmented Lagrangian relaxation for analytical target cascading using the alternating direction method of multipliers

Analytical target cascading is a method for design optimization of hierarchical, multilevel systems. A quadratic penalty relaxation of the system consistency constraints is used to ensure subproblem feasibility. A typical nested solution strategy consists of inner and outer loops. In the inner loop, the coupled subproblems are solved iteratively with fixed penalty weights. After convergence of the inner loop, the outer loop updates the penalty weights. The article presents an augmented Lagrangian relaxation that reduces the computational cost associated with ill-conditioning of subproblems in the inner loop. The alternating direction method of multipliers is used to update penalty parameters after a single inner loop iteration, so that subproblems need to be solved only once. Experiments with four examples show that computational costs are decreased by orders of magnitude ranging between 10 and 1000.     

Thiol compounds as corrosion inhibitors of carbon steel (XC 38) in sodium chloride medium

The study of thio compounds as inhibitors against the corrosion of a carbon steel (XC 38) in contact with 3% sodium chloride using a rotating disk electrode was performed. Stationary and transient measurements were carried out. Inhibition efficiency was estimated from both current-potential characteristics and gravimetric measurements. With the most efficient inhibitor, orthoaminothiophenol (OATP), the inhibition mechanism was studied. Interpretation of the results implies the formation of a thick and compact inhibitor film. The OATP acts by considerably reducing the active area without modifying the mechanism of anodic and cathodic processes.     

Electropolymerisation de monomere 3-amino-1,2,4-triazole sur une electrode de cuivre et effet du polymere sur la corrosion de l'electrode en milieu NaCl 3%

Résumé L'electropolymérisation d'un nouveau polymére a partir de 3-amino-triazole (ATA) est réalisée. L'électrolyte support était de L'eau distillée avec un mélange de méthanol et de KOH. Le microscope électronique à balayage (MEB), la voltammétrie cyclique et le chronoampérométrie ont été utilisées pour caractériser le nouveau polymere. Ces mêmes techniques ont été employees pour étudier la nature du mécanisme d'inhibition de la corrosion du cuivre en milieu NaCl 3% par suite de la formation du polymere. L'électropolymérisation in situ du monomére donne lieu à un polymère isolant. Le traitement thermique du polymère améliore son homogénéité et son adhérence à l'électrode. Un mécanisme de la formation du poly-ATA est proposé. La formation du polymere aboutit à une diminution des courants cathodique et anodique. Les vitesses des réactions de réduction de l'óxygène et de dissolution du cuivre ont été remarquablement diminuées.

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The electrochemical polymerization of a new polymer is described. The monomer used was 3-amino-1,2,4-triazole (ATA) and the supporting medium was distilled water/methyl alcohol containing KOH. Scanning electronic microscopy (SEM), cyclic voltammetry and chronoamperometry were used, to characterize the new polymer. The same techniques were also used to study the nature of corrosion inhibition processes caused by the formation of the polymer on copper in NaCl 3%. The in-situ electropolymerization of the monomer gives an insulating polymer. Heat treatment of the polymer improves its homogeneity and adherence to the copper electrode on which it is formed. A mechanism for the formation of the poly-ATA is proposed. The formation of the polymer gives rise to a decrease in both anodic and cathodic currents. The rates of oxygen reduction and copper dissolution reactions are considerably decreased.

     

Effect of a Bulk Forming Laxative on the Bioavailability of Carbamazepine in Man

The influence of a bulk forming laxative consisting of 3.5g. Ispaghula Husk (Plantago seeds) on the bioavailability of Carbamazepine from commercial tablets was studied in four healthy male volunteers. The drug was administered as a single oral dose of 200 mg. Evaluation of the absorption was done by means of the plasma concentration measurements. Seven blood samples were collected over a 24-h period following carbamazepine administration and the drug plasma concentrations were determined by HPLC. The data were statistically analyzed by the t-test for paired observations and were subjected to a stripping computer program to obtain the relevant bioavailability values.     

Molybdenum Oxide Nanosheets with Tunable Plasmonic Resonance: Aqueous Exfoliation Synthesis and Charge Storage Applications

Herein, a simple aqueous‐exfoliation strategy is introduced for the fabrication of a series of MoO_3?x nanosheets (where x stands for oxygen vacancies) using two commercial molybdenum oxide precursors, MoO₂ and MoO₃. The nanosheets offer a localized surface plasmon resonance (LSPR) effect which is dependent on the structure and local environment of the nanosheets. The LSPR can be efficiently tuned by changing the weight ratio between the molybdenum oxide precursor(s) and/or by solar light irradiation using a low‐energy UV lamp (36 W). For the pristine MoO_3?x nanosheets, the highest LSPR signal is obtained for nanosheets prepared using 80% MoO₂. On the contrary, after solar light irradiation, the nanosheets prepared using pure MoO₃ offer the highest LSPR response. The nanosheets also show an outstanding rate capability when used as binder‐free supercapacitor electrodes in an acidified Na₂SO₄ electrolyte. The electrodes exhibit discharge capacities of 110 and 75 C g^?1 at a scan rate of 20 and 1000 mV s^?1, respectively. The MoO_3?x nanosheets can likewise be used as a negative electrode material for lithium‐ion batteries. The efficient eco‐friendly synthesis and the ability to tune the photochemical and electrochemical properties of the nanosheets make this approach interesting to many energy‐related research fields.     

On the conditional acceptance of iterates in SAO algorithms based on convex separable approximations

We reflect on the convergence and termination of optimization algorithms based on convex and separable approximations using two recently proposed strategies, namely a trust region with filtered acceptance of the iterates, and conservatism. We then propose a new strategy for convergence and termination, denoted filtered conservatism, in which the acceptance or rejection of an iterate is determined using the nonlinear acceptance filter. However, if an iterate is rejected, we increase the conservatism of every unconservative approximation, rather than reducing the trust region. Filtered conservatism aims to combine the salient features of trust region strategies with nonlinear acceptance filters on the one hand, and conservatism on the other. In filtered conservatism, the nonlinear acceptance filter is used to decide if an iterate is accepted or rejected. This allows for the acceptance of infeasible iterates, which would not be accepted in a method based on conservatism. If however an iterate is rejected, the trust region need not be decreased; it may be kept constant. Convergence is than effected by increasing the conservatism of only the unconservative approximations in the (large, constant) trust region, until the iterate becomes acceptable to the filter. Numerical results corroborate the accuracy and robustness of the method.     

Quantifying variability of batching equipment using effective process times

Process time variability plays a key role in the cycle time of wafers. Several sources of variability can be distinguished. However, identification and measurement of all individual sources is almost impossible. Therefore, in previous work, a new method has been proposed to measure effective process times (EPT) for single-lot machines. The EPT incorporates the various sources of variability. From the measured EPT realizations, the mean and the corresponding coefficient of variation can be computed for queueing performance analysis. This paper follows up on previous work. The EPT quantification approach is generalized toward batching equipment. The batching types of operations are commonly present in the semiconductor industry. The paper proposes a transformation algorithm that transforms lot events into batch events. This enables one to use the previously developed single-lot algorithm also for batch machine workstations. An industry case illustrates the approach using operational data of furnace workstations.     

Characterization of operational time variability using effective process times

Operational time variability is one of the key parameters determining the average cycle time of lots. Many different sources of variability can be identified such as machine breakdowns, setup, and operator availability. However, an appropriate measure to quantify variability is missing. Measures such as overall equipment effectiveness (OEE) used in the semiconductor industry are entirely based on mean value analysis and do not include variances. The main contribution of this paper is the development of a new algorithm that enables estimation of the mean effective process time t/sub e/ and the coefficient of variation c/sub e//sup 2/ of a multiple machine workstation from real fab data. The algorithm formalizes the effective process time definitions as known in the literature. The algorithm quantifies the claims of machine capacity by lots, which include time losses due to down time, setup time, and other irregularities. The estimated t/sub e/ and c/sub e//sup 2/ values can be interpreted in accordance with the well-known G/G/m queueing relations. Some test examples as well as an elaborate case from the semiconductor industry show the potential of the new effective process time algorithm for cycle time reduction programs.     

A micro-accelerometer MDO benchmark problem

Many optimization and coordination methods for multidisciplinary design optimization (MDO) have been proposed in the last three decades. Suitable MDO benchmark problems for testing and comparing these methods are few however. This article presents a new MDO benchmark problem based on the design optimization of an ADXL150 type lateral capacitive micro-accelerometer. The behavioral models describe structural and dynamic effects, as well as electrostatic and amplification circuit contributions. Models for important performance indicators such as sensitivity, range, noise, and footprint area are presented. Geometric and functional constraints are included in these models to enforce proper functioning of the device. The developed models are analytical, and therefore highly suitable for benchmark and educational purposes. Four different problem decompositions are suggested for four design cases, each of which can be used for testing MDO coordination algorithms. As a reference, results for an all-in-one implementation, and a number of augmented Lagrangian coordination algorithms are given.