Renormalization Group-Based Transport Modeling of Premixed Turbulent Combustion: I. Incompressible Deflagration Model

A new method for numerical modeling of premixed turbulent combustion is introduced based on the thin flame model. Applications are given, e.g., to flames in turbulent flow in channels and over backward facing steps.     

Network Observability Analysis through Measurement Jacobian Matrix Reduction

A method of observability analysis for the state estimation in power systems is presented. The method is based on a symbolic reduction of the measurement Jacobian matrix without its actual computation. The algorithm is characterized as being extremely simple and fast. The results of the algorithm application in the Energy Management System (EMS) of a large electric utility are given.     

Daytime operation of a pure rotational Raman lidar by use of a Fabry-Perot interferometer

We propose to use a Fabry-Perot interferometer (FPI) in a pure rotational Raman lidar to isolate return signals that are due to pure rotational Raman scattering from atmospheric nitrogen against the sky background. The main idea of this instrumental approach is that a FPI is applied as a frequency comb filter with the transmission peaks accurately matched to a comb of practically equidistant lines of a pure rotational Raman spectrum (PRRS) of nitrogen molecules. Thus a matched FPI transmission comb cuts out the spectrally continuous sky background light from the spectral gaps between the PRRS lines of nitrogen molecules while it is transparent to light within narrow spectral intervals about these lines. As the width of the spectral gaps between the lines of the PRRS of nitrogen molecules is -114 times the width of an individual spectral line, cutting out of the sky background from these gaps drastically improves the signal-to-background ratio of the pure rotational Raman lidar returns. This application of the FPI enables one to achieve daytime temperature profiling in the atmosphere with a pure rotational Raman lidar in the visible and near-UV spectral regions. We present an analysis of application of the FPI to filtering out the pure rotational Raman lidar returns against the solar background. To demonstrate the feasibility of the approach proposed, we present temperature profiles acquired during a whole-day measurement session in which a Raman lidar equipped with a FPI was used. For comparison, temperature profiles acquired with Vaisala radiosondes launched from the measurement site are also presented.     

Fluctuation-dissipation theorem and models of learning

Advances in statistical learning theory have resulted in a multitude of different designs of learning machines. But which ones are implemented by brains and other biological information processors? We analyze how various abstract Bayesian learners perform on different data and argue that it is difficult to determine which learning-theoretic computation is performed by a particular organism using just its performance in learning a stationary target (learning curve). Based on the fluctuation-dissipation relation in statistical physics, we then discuss a different experimental setup that might be able to solve the problem.     

An easy way to Pd–Zn nanoalloy with defined composition from a heterobimetallic Pd(μ–OOCMe)4Zn(OH2) complex as evidenced by XAFS and XRD

The heterobimetallic lantern complex Pd(μ-OOCMe)₄Zn(OH₂) was found to be readily reduced with H₂ under fairly mild conditions (150–250 °C, 5–10% H₂/He) both in the carbon-supported and crystalline states to afford a Pd–Zn nanoalloy as evidenced by the ICP elemental analysis, EXAFS, XANES and XRD data.      

Set-Valued Means of Random Particles

Planar images of powder particles or sand grains can be interpreted as figures, i.e., equivalence classes of directlycongruent compact sets. The paper introduces a concept of set-valuedmeans and real-valued variances for samples of such figures. Inobtaining these results, the images are registered to have similarlocations and orientations. The method is applied to find a mean figure of a sample of polygonal particles.     

Nonlinear Convective Flows in a Laterally Heated Two-Layer System with a Temperature-Dependent Heat Release/Consumption at the Interface

Nonlinear convective flows developed under the joint action of buoyant and thermocapillary effects in a laterally heated two-layer system filling the closed cavity, have been investigated. The influence of a temperature-dependent interfacial heat release/consumption on nonlinear steady and oscillatory regimes, has been studied. It is shown that sufficiently strong temperature dependence of interfacial heat sinks and heat sources can change the sequence of bifurcations and lead to the development of specific oscillatory regimes in the system.     

Effect of Orthorhombicity on the Electronic Structure and Superconducting Properties of High- $$T_c$$ T c Cuprate Family

Journal of Superconductivity and Novel Magnetism - Electronic structure in the normal state and properties in the superconducting state of the orthorhombic phase in HTSC cuprates are studied within...     

Framework for Scalable File System Metadata Crawling and Differencing

Identifying file systems metadata changes such as which files have been added, modified or removed from the file system has many usages. In this paper we present a framework we developed for identifying those changes in increasing speeds. Our framework which is composed of crawling, hashing, and scheduling components, allows to scale the crawl to multiple client workstations that operate in parallel on the same file system in a non-overlapping fashion. Experiments carried using real-world data indicate performance improvement (speedup) of up to 36X using our framework compared to legacy crawling utilities such as Linux’s ‘find’.