Wavelength conversion for FM light using light injection induced frequency shift in DFB-LD

A novel wavelength conversion is described. Wavelength conversion of frequency-modulated (FM) light is achieved by combining the lasing frequency shift induced by external light in a DFB-LD and the FM-IM conversion function of a Mach-Zehnder optical filter. In the experiment, 1534 nm FM light is converted to 1550 nm light.<>     

Non-unitary master equation for the internal state of ions traversing solids

We present a new method describing the time development of the internal state of fast highly charged ions subject to collisions and to spontaneous radiative decay during transport through solids. Our method describes both the build-up of coherences and the decoherence of the open quantum system due to the interaction with its environment. The dynamics of the reduced density matrix is governed by a Lindblad master equation that can be solved by Monte Carlo sampling techniques. In practice, the standard Lindblad equation can be of limited value because it describes strictly unitary time transformations of the reduced density matrix. We have developed a generalized non-unitary Lindblad form (and its Monte Carlo implementation) for the evolution in finite subspaces in which the coupling to the complement is taken into account. We use the radiative decay of a free hydrogenic atom in vacuum as a simple test case. We present an application for Kr³⁵⁺ ions traversing carbon foils with varying thickness and compare our results with experiments.     

EFFECT OF IRON CATALYST ON THE COMPOSITION OF OIL FROM COAL LIQUEFACTION

The effect of two iron catalysts, red mud and CGS S-G, as well as C0-Mo/AI₂O3 and Ni-Mo/Al₂03 commercial catalysts on the composition of oil derived from the liquefaction of Japanese subbituminous coal have been investigated comparatively by conventional autoclave experiments at 440 and 450^°C under initial hydrogen pressure of 85kg/cm² G with tetralin to coal weight ratio of 3. From the results obtained at 450^°C, total conversion and the yield of gas revealed almost same level with four catalysts, but the oil product from molybdenum catalysts showed higher yield than that from iron catalysts. CGS S-G catalyst also showed higher yield of oil product than red mud catalyst. Reaction behavior of two iron catalysts were also tested by solvent recycle mode experiments.     

Establishing Specificity in Psychotherapy: A Meta-Analysis of Structural Equivalence of Placebo Controls.

Placebo treatments in psychotherapy cannot adequately control for all common factors, which thereby attenuates their effects vis-à-vis active treatments. In this study, the authors used meta-analytic procedures to test one possible factor contributing to the attenuation of effects: structural inequalities between placebo and active treatments. Structural aspects of the placebo included number and duration of sessions, training of therapist, format of therapy, and restriction of topics. Results indicate that comparisons between active treatments and structurally inequivalent placebos produced larger effects than comparisons between active treatments and structurally equivalent placebos: moreover, the latter comparison produced negligible effects, indicating that active treatments were not demonstrably superior to well-designed placebos. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Two-chip MPEG-2 video encoder

Our two-chip, real time, MPEG-2, simple-profile-at-main-level encoder supports NTSC 4:2:0 video signals with only three external memories. We have developed a compact encoder chip set. The key features of this chip set are a low encoding delay based on a simple profile at main level; wide-range motion estimation, which it performs using a hierarchical search; a flexible, macroblock level pipeline architecture based on RISC CPUs; and three small peripherals with no glue logic: a VRAM, synchronous DRAM, and FIFO DRAM     

Dynamic Assignment of Gaussian Components in Modelling Speech Spectra

In this paper, we describe a parametric mixture model for modelling the resonant characteristics of the vocal tract where Gaussian distributions are used to model spectral frequency regions. A mixtures of Gaussian (MoG) based parametrisation scheme is used for modelling a smoothed representation of the spectra. This smoothing procedure removes all signal periodicity from the spectra allowing highly natural analysis, manipulation and synthesis of speech. The goal of this parametrisation scheme is to ease the correspondence between the resonant characteristics of the vocal tract and the parametric distributions and modelling the spectrum with an appropriate number of parameters. Previously, a maximum likelihood (ML) approach to this parametrisation scheme was introduced. However, this approach has inherent local optima problems. Noting that, a relatively small class of Gaussian densities can approximate a large class of distributions, we propose a new scheme whereby starting with a large number of distributions in the mixture, we systematically reduce their number and re-approximate the densities in the mixture based on a distance criterion. The Kullback-Leibler (KL) distance was found to allow optimal MoG solutions to the spectra. Furthermore, a fitness measure based on KL information is used to provide a figure for estimating the model order in representing formant-like features. The proposed model is subjectively evaluated and is shown to reduce the number of Gaussian with an appreciable loss in the quality of the re-synthesised speech.     

Finding and Quantitative Evaluation of Minute Flaws on Metal Surface Using Hairline

A method to detect minute flaws on metal parts is proposed to remove defective parts before assembling in a factory. The input grayscale images of metal parts are directly used to recognize flaws without any image conversion to shorten recognition time. The recognition problem to find flaws and detect their position on the metal parts is converted to another problem that searches for the maximum peak and the variables producing the peak. Then, the recognition problem can be treated as an optimization problem, and this conversion allows us to utilize high genetic algorithm performances in optimization. The effectiveness and problems of the proposed method are studied on the standing points of recognition speed and quantitative recognition ability. Based on the analysis, we furthermore improved our system to increase the flaw detection rate; the lighting direction was changed to find the best lighting condition that can emphasize the contrast between the metal surface and the flaw by using the reflection character of the hairline on the metal, which is resulted by a polishing process     

Creep properties and microstructural evolution of austenitic TEMPALOY steels

The steam parameters in the new high efficiency fossil fuel power plants are continuously increasing, requiring new advanced materials with enhanced creep strength able to operate on the most severe temperature and pressure conditions. For super-heater and re-heater applications, TEMPALOY AA-1 steel, an evolution of 18Cr10NiNbTi alloy, has been developed through the addition of 3%Cu and B, significantly enhancing the creep resistance, while offering typical corrosion properties of 18%Cr steels. This paper describes Tenaris’ tubular products in the field of austenitic grades for applications in Ultra Super Critical power plants: the production route and the main microstructural and mechanical properties of TEMPALOY AA-1 and TEMPALOY A-3 steels, including the effect of shot blasting on steam-oxidation resistance, their creep–rupture properties and their microstructural evolution during temperature exposure are presented.