Search results for "Gram"

Competition of electron-phonon mediated superconductivity and Stoner magnetism on a flat band

2018

The effective attractive interaction between electrons, mediated by electron-phonon coupling, is a well-established mechanism of conventional superconductivity. In metals exhibiting a Fermi surface, the critical temperature of superconductivity is exponentially smaller than the characteristic phonon energy. Therefore, such superconductors are found only at temperatures below a few kelvin. Systems with flat energy bands have been suggested to cure the problem and provide a route to room-temperature superconductivity, but previous studies are limited to only BCS models with an effective attractive interaction. Here we generalize Eliashberg's theory of strong-coupling superconductivity to syst…

Agent assisted interactive algorithm for computationally demanding multiobjective optimization problems

2015

We generalize the applicability of interactive methods for solving computationally demanding, that is, time-consuming, multiobjective optimization problems. For this purpose we propose a new agent assisted interactive algorithm. It employs a computationally inexpensive surrogate problem and four different agents that intelligently update the surrogate based on the preferences specified by a decision maker. In this way, we decrease the waiting times imposed on the decision maker during the interactive solution process and at the same time decrease the amount of preference information expected from the decision maker. The agent assisted algorithm is not specific to any interactive method or s…

Rural Renewal Program in the Aspect of Sustainable Development of Rural Areas in the Opinion of Respondents from the Opole Voivodeship

2018

Sustainable development has a complex nature and is represented by economic, social and ecological pillars. Connected with the concept of multifunctionality on the rural areas it translates by diverse economic activities carried out with respect for environmental aspects, with the development of social and cultural functions, and with the attention to ensure good living conditions for the inhabitants. Effective achievement of sustainable development goals needs constant and consistent raising of public awareness, as well as an increase in the public access to information and its participation in the decision-making process. The aim of the paper is to assess, basing on the respondents‘ opini…

What Can You Achieve in Eight Years? : A Case Study on Participation, Effectiveness, and Overall Impact of a Comprehensive Workplace Health Promotion…

2019

Objective: To investigate participation and effectiveness of a multiyear comprehensive workplace health promotion (WHP) program. Methods: Participation and effectiveness data came from employer and vendor systems. Health data came from health risk assessments (HRA) and biometric screenings. Participation and effectiveness were analyzed using descriptive analyses, T-tests and Mann-Whitney U tests where appropriate. Overall impact was assessed using the PIPE Impact Metric. Results: 86% of employees completed the HRA and 80% the biometrical screenings. Annual participation rate was 24%, and total reach was 58%. The portion of successful participants was 23% in 2010–2013 and 18% in 2014–2017. P…

Diaboliskie spēki Raiņa dramaturģijā

2013

Elektroniskā versija nesatur pielikumus

VAPOR-LIQUID EQUILIBRIUM CALCULATIONS USING THE TOPOLOGICAL TREATMENT OF MIXTURES.

1983

The Topological Treatment of mixtures is applied to several kinds of binary mixtures to obtain VLE diagrams. The excess Gibbs free energy, gE, is calculated as the product of a topological vector and an information vector. The pure compound topological description were obtained following the DARC system rules. A weighting function was introduced to obtain the topological description of a mixture. The information vector is calculated from experimental data. It is shown that for binary mixtures alcohol-alkane, the components of this vector varies linearly with the average number of carbon atoms of chemical compounds. This relationship allows prediction of the VLE diagram for any other system …

Operator (Quasi-)Similarity, Quasi-Hermitian Operators and All that

2016

Motivated by the recent developments of pseudo-Hermitian quantum mechanics, we analyze the structure generated by unbounded metric operators in a Hilbert space. To that effect, we consider the notions of similarity and quasi-similarity between operators and explore to what extent they preserve spectral properties. Then we study quasi-Hermitian operators, bounded or not, that is, operators that are quasi-similar to their adjoint and we discuss their application in pseudo-Hermitian quantum mechanics. Finally, we extend the analysis to operators in a partial inner product space (pip-space), in particular the scale of Hilbert space s generated by a single unbounded metric operator.

Modal analysis for random response of MDOF systems

1990

The usefulness of the mode-superposition method of multidegrees of freedom systems excited by stochastic vector processes is here presented. The differential equations of moments of every order are written in compact form by means of the Kronecker algebra; then the method for integration of these equations is presented for both classically and non-classically damped systems, showing that the fundamental operator available for evaluating the response in the deterministic analysis is also useful for evaluating the response in the stochastic analysis.

Polaroid-Type Operators

2018

In this chapter we introduce the classes of polaroid-type operators, i.e., those operators T ∈ L(X) for which the isolated points of the spectrum σ(T) are poles of the resolvent, or the isolated points of the approximate point spectrum σap(T) are left poles of the resolvent. We also consider the class of all hereditarily polaroid operators, i.e., those operators T ∈ L(X) for which all the restrictions to closed invariant subspaces are polaroid. The class of polaroid operators, as well as the class of hereditarily polaroid operators, is very large. We shall see that every generalized scalar operator is hereditarily polaroid, and this implies that many classes of operators acting on Hilbert s…

1973

The direct and the inverse problem of the light scattering from dilute polymer solutions is solved for GAUssian coils at the theta point. Theoretical scattering functions and their derivatives are analytically calculated for the general gamma distribution of molecular weights as a function of the non-uniformity and the weight average molecular weight, and also for various ratios of the statistical segment length of the coil to the wave length of the scattered light. The asymptote and the tangent of P are obtained by analysing the operator in the ZIMM equation and their mutual position is compared in the angle range 150° to 180°. The scattering envelopes of microgel systems are analytically …