Search results for "process"
showing 10 items of 22310 documents
Non-linear systems under parametric alpha-stable LÉVY WHITE NOISES
2005
In this study stochastic analysis of nonlinear dynamical systems under a-stable, multiplicative white noise has been performed. Analysis has been conducted by means of the Ito rule extended to the case of α-stable noises. In this context the order of increments of Levy process has been evaluated and differential equations ruling the evolutions of statistical moments of either parametrically and external dynamical systems have been obtained. The extended Ito rule has also been used to yield the differential equation ruling the evolution of the characteristic function for parametrically excited dynamical systems. The Fourier transform of the characteristic function, namely the probability den…
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.
Stealth dicing with Bessel beams and beyond
2016
In the context of laser cutting of transparent materials, we investigate glass cleaving with Bessel beams and report that a modification of the beam with 3 main lobes drastically enhances cleavability and reduces defects.
Bounds for Bessel functions
1989
We establish lower and upper bounds for the Bessel functionJ v (x) and the modified Bessel functionI v(x) of the first kind. Our chief tool is the differential equation satisfied by these functions.
Regularity of a Degenerated Convolution Semi-Group Without to Use the Poisson Process
2011
We translate in semi-group theory our regularity result for a degenerated convolution semi-group got by the Malliavin Calculus of Bismut type for Poisson processes.
Improved Quadratic Time-frequency Distributions for Detecting Inter-turn Short Circuits of PMSMs in Transient States
2020
This paper aims to improve quadratic time-frequency distributions to adapt condition monitoring of electrical machines in transient states. Short-Time Fourier transform (STFT) has been a baseline signal processing technique for detecting fault characteristic frequencies. However, limits of window sizes due to loss of frequency- or time-resolution, make it hard to capture rapid changes in frequencies. Within this study, Choi-Williams and Wigner-Ville distributions are proposed to effectively detect peaks at characteristic frequencies while still maintaining low computation time. The improved quadratic time-frequency distributions allow for generating spectrograms of a longer lasting data sig…
A comparison between two feature selection algorithms
2017
This article provides a comparison of two feature selection algorithms, Information Gain Thresholding and Koller and Sahami's algorithm in the context of text document classification on the Reuters Corpus Volume 1 dataset. The algorithms were evaluated by testing the performance of classifiers trained on the features they select from a given dataset. Results show that Koller and Sahami's algorithm consistently outperforms Information Gain Thresholding by capturing interactions between features and avoiding redundancy among features, although it achieves its gains through increased complexity and longer running time.
Poliolefiny a środowisko
2002
Przedstawiono znaczenie, rozwój metod otrzymywania, kierunki zastosowania i perspektywy rozwoju poliolefin (polietylenu i polipropylenu), materiałów dominujących w światowej produkcji i zużyciu tworzyw sztucznych. Scharakteryzowano oddziaływania tych polimerów na środowisko, kolejno w etapie ich wytwarzania, wykorzystywania i utylizacji odpadów poużytkowych. Scharakteryzowano także kierunki badań prowadzonych w Instytucie Chemii Uniwersytetu Opolskiego w zakresie syntezy, charakterystyki, a przede wszystkim temo- i fotooksydacyjnej degradacji oraz starzenia atmosferycznego poliolefin.
Regional differences in Italian students' performance: a simulation model
2017
This work presents the first results of a research project seeking to build a simulation model able to reproduce the differences of Italian students’ performance at regional level. A preliminary qualitative cause-and-effect model defines the main variable involved in the inter-generational skill formation processes, as well as their interplay with the job market context and the triggering of motivational forces for new skill acquisition. Such model was designed according to a system dynamics perspective, considered suitable for capturing the interrelatedness of key variables and for providing useful simulation tools to conduct and communicate future scenario analyses. Keywords: regional…
Performance Management in Local Government: The Application of System Dynamics to Promote Data Use
2014
The purpose of this article is to demonstrate how system dynamics can be used to enrich performance management in local government, focusing specifically on how the development of conceptual and simulation system dynamic models can foster a shared view of the relevant system among stakeholders to overcome factors that limit data use. Responding to this purpose, we present a normative case study on how key drivers can be used to foster a shared view of the residential refuse collection system for supporting policy and process changes. A major finding from our research, however, is that performance management cannot overlook the broader forces of citizenship outcomes that impact the community.