Dynamics of Wave Scintillation in Random Media

This paper concerns the asymptotic structure of the scintillation function in the simplified setting of wave propagation modeled by an Itô–Schrödinger equation. We show that the size of the scintillation function crucially depends on the smoothness of the initial conditions for the wave equation and on the size of the “array of detectors” where the wave fields are measured. In many practical settings, we show that the estimates are optimal and devise an equation for the appropriately rescaled scintillation function. The estimates are based on a careful analysis of Wigner transforms and of linear kinetic equations involving oscillatory integrals.     

多元分析方法在发电技术经济中的应用

本文综合运用因子分析 ,聚类分析等多元统计分析的方法 ,对我国不同地区发电技术水平进行综合分析与评价 ,并划分等级 .     

Blind separation of vibration signals and source change detection – Application to machine monitoring

The paper presents a new approach for machine vibration analysis and health monitoring combining blind source separation (BSS) and change detection in source signals. So, the problem is transferred from the original space of the measurements to the space of independent sources, where the reduced number of components is going to simplify the monitoring problem while the change detection methods are going to be applied for scalar signals. The assessment of the approach on a real machine is presented in this paper.     

On the entropy minimization problem in Statistical Mechanics

In many works on Statistical Mechanics and Statistical Physics, when deriving the distribution of particles of ideal gases, one uses the method of Lagrange multipliers in a formal way. In this paper we treat rigorously this problem for Bose–Einstein, Fermi–Dirac and Maxwell–Boltzmann entropies and present a complete study in the case of the Maxwell–Boltzmann entropy. Our approach is based on recent results on series of convex functions.     

A Characterization of Uniform Rotundity in Every Direction in Terms of Rough Convergence

We characterize uniform rotundity in every direction by means of rough convergence. This characterization still holds if we shift to rough statistical convergence. We also study the latter convergence in normed spaces.     

Assessment of statistical uncertainty in the quantitative analysis of solid samples in motion using laser-induced breakdown spectroscopy

Statistical uncertainty in the quantitative analysis of solid samples in motion by laser-induced breakdown spectroscopy (LIBS) has been assessed. For this purpose, a LIBS demonstrator was designed and constructed in our laboratory. The LIBS system consisted of a laboratory-scale conveyor belt, a compact optical module and a Nd:YAG laser operating at 532 nm. The speed of the conveyor belt was variable and could be adjusted up to a maximum speed of 2 m s^− 1. Statistical uncertainty in the analytical measurements was estimated in terms of precision (reproducibility and repeatability) and accuracy. The results obtained by LIBS on shredded scrap samples under real conditions have demonstrated that the analytical precision and accuracy of LIBS is dependent on the sample geometry, position on the conveyor belt and surface cleanliness. Flat, relatively clean scrap samples exhibited acceptable reproducibility and repeatability; by contrast, samples with an irregular shape or a dirty surface exhibited a poor relative standard deviation.     

Steepest entropy increase is justified by information theory. The relations between Ziegler’s principle, Onsager’s formalism and Prigogine’s principle

Evidence for Ziegler’s principle of maximum entropy production has been accumulated from different fields such as climatic studies, crystal growth, dynamics of ecosystems and cellular metabolism. However, Ziegler’s principle is still seen with scepticism by the scientific community. The reasons for this scepticism are the absence of an accepted theoretical justification as well as the fact that Ziegler’s principle formulation seems to contradict Prigogine’s principle of minimum entropy production. In this work we aim to provide a theoretical justification for Ziegler’s principle based on information theory, which is at the basis of Gibbs’ formalism for statistical physics. Similar approaches have previously been attempted, however we believe that the justification provided here is simpler and relies in less questionable hypotheses. Once Ziegler’s principle has been formulated as a consequence of information theory, its relations with Onsager’s formulation and Prigogine’s principle are explored.     

Capture of asymmetric top dipolar molecules by ions: Rate constants for capture of H2O, HDO, and D2O by arbitrary ions

The capture of rotationally state-selected and unselected asymmetric top polar molecules by ions is investigated. Analytical expressions (for all rotational states up to j = 2) of capture rate constants in the perturbed-rotor second-order limit are derived for application to low temperature conditions. Approximate analytical representations over wider temperature ranges are also given for rotationally unselected molecules. The capture of H₂O, D₂O, and HDO by arbitrary ions is chosen for demonstration of the approach. Capture rate constants for the about 60 reactions of H₂O with ions listed in the UMIST 2006 data base for astrochemistry are calculated, compared with experimental data, and represented in the format k_cap(T) ≈ c₁ + c₂(T/300 K)^−1/2. The parameters c₁ and c₂ can be predicted in a very simple way. The approach allows one to identify capture-controlled mechanisms and/or to trace experimental artifacts. The approach applies equally well to the capture of symmetric top and linear dipole molecules by arbitrary ions.     

Characterizing the origins of bottled water on the South Korean market using chemical and isotopic compositions

We analyzed the major elements and stable isotopes of oxygen, hydrogen, and carbon (dissolved inorganic carbon: DIC) in various types of bottled water (domestic and foreign) commercially available in South Korea to classify the water types and to identify their origins. Only marine waters and some sparkling waters could be discriminated by their physicochemical compositions. Oxygen and hydrogen isotopes made marine waters more distinguishable from other water types. The determination of the carbon isotope composition of DIC was clearly useful for distinguishing between naturally and artificially sparkling waters. In addition, statistical analysis also appeared to aid in the discrimination of bottled water types. Our results indicate that a method that combines chemical and stable isotope composition analysis with statistical analysis is the most useful for discriminating water types and characterizing the origins of bottled water.