| | SLO | ENG | Piškotki in zasebnost

Večja pisava | Manjša pisava

Iskanje po katalogu digitalne knjižnice Pomoč

Iskalni niz: išči po
išči po
išči po
išči po
* po starem in bolonjskem študiju


1 - 10 / 37
Na začetekNa prejšnjo stran1234Na naslednjo stranNa konec
Evaluation of Green`s function for vertical point-load excitation applied to the surface of a semi-infinite elastic medium
Andrej Štrukelj, Tomaž Pliberšek, Andrej Umek, 2006, izvirni znanstveni članek

Opis: The topic of this paper is to show that the integrals of infinite extent representing the surface displacements of a layered half-space loaded by a harmonic, vertical point load can be reduced to integrals with finite integration range. The displacements are first expressed through wave potentials and the Hankel integral transform in the radial coordinate is applied to the governing equations and boundary conditions, leading to the solutions in the transformed domain. After the application of the inverse Hankel transform it is shown that the inversion integrands are symmetric/antimetric in the transformation parameter and that this characteristic is preserved for any number of layers. Based on this fact the infinite inversion integrals are reduced to integrals with finite range by choosing the suitable representation of the Bessel function and use of the fundamental rules of contour integration, permitting simpler analytical or numerical evaluation. A numerical example is presented and the results are compared to those obtained by the CLASSI program.
Ključne besede: civil engineering, soil mechanics, Green`s function, layered half-space, vertical point load
Objavljeno: 31.05.2012; Ogledov: 1590; Prenosov: 10
URL Povezava na celotno besedilo

An efficient k'-means clustering algorithm
Krista Rizman Žalik, 2008, izvirni znanstveni članek

Opis: This paper introduces k'-means algorithm that performs correct clustering without pre-assigning the exact number of clusters. This is achieved by minimizing a suggested cost-function. The cost-function extends the mean-square-error cost-function of k-means. The algorithm consists of two separate steps. The first is a pre-processing procedure that performs initial clustering and assigns at least one seed point to each cluster. During the second step, the seed-points are adjusted to minimize the cost-function. The algorithm automatically penalizes any possible winning chances for all rival seed-points in subsequent iterations. When the cost-function reaches a global minimum, the correct number of clusters is determined and the remaining seed points are located near the centres of actual clusters. The simulated experiments described in this paper confirm good performance of the proposed algorithm.
Ključne besede: algorithms, clustering analysis, k-means, cost-function, rival penalized mechanism, datasets
Objavljeno: 31.05.2012; Ogledov: 1405; Prenosov: 88
URL Povezava na celotno besedilo

Approximate expressions for the Green's functions of a semi-infinite, elastic medium
Tomaž Pliberšek, Andrej Umek, 2010, izvirni znanstveni članek

Opis: On the basis of an exact, discretized presentation of the Green's function components, their closed-form approximations are developed. Their accuracy is considered to be better than the tolerances in the intrusive measurements data for the identification of the mechanical characteristics of soils. The use of these approximate expressions is believed to considerably reduce the computational effort in soil-structure interaction problems and open up new possibilities for the non-intrusive identification of soils.
Ključne besede: elastodynamics, half-space, Green's function, approximate solutions
Objavljeno: 31.05.2012; Ogledov: 1382; Prenosov: 83
.pdf Celotno besedilo (220,92 KB)
Gradivo ima več datotek! Več...

A multidomain boundary element method for two equation turbulence models
Matjaž Ramšak, Leopold Škerget, 2005, izvirni znanstveni članek

Opis: The paper deals with the multidomain Boundary Element Method (BEM) for modelling 2D complex turbulent flow using low Reynolds two equation turbulence models. While the BEM is widely accepted for laminar flow this is the first case, where this method is applied for complex flow problems using ▫$k-epsilon$▫ turbulence model. The integral boundary domain equations are discretised using mixed boundary elements and a multidomain method also known as subdomain technique. The resulting system matrix is overdetermined, sparse, block banded and solved using fast iterative linear least squares solver. The simulation of turbulent flow over a backward step is in excellent agreement with the finite volume method using the same turbulent model.
Ključne besede: fluid mechanics, turbulent flow, boundary element method, incompressible viscous fluid, stream function-vorticity formulation, two equation turbulence model, backward facing step flow
Objavljeno: 01.06.2012; Ogledov: 1223; Prenosov: 65
URL Povezava na celotno besedilo

A multidomain boundary element method for unsteady laminar flow using stream function-vorticity equations
Matjaž Ramšak, Leopold Škerget, Matjaž Hriberšek, Zoran Žunič, 2005, izvirni znanstveni članek

Opis: The paper deals with the Boundary Element Method (BEM) for modelling 2D unsteady laminar flow using stream function-vorticity formulation of the Navier-Stokes equations. The numerical algorithm for solving a general parabolic diffusion-convection equation is based on linear mixed elements and a multidomain model also known as subdomain technique. Robustness, accuracy and economy of the developed numerical algorithm is shown on a standard case of steady backward facing step flow and a periodic flow past a circular cylinder test case.
Ključne besede: fluid mechanics, viscous fluid, unsteady laminar flow, boundary element method, multidomain model, stream function, vorticity formulation, backward facing step flow, flow past a cylinder
Objavljeno: 01.06.2012; Ogledov: 1449; Prenosov: 73
URL Povezava na celotno besedilo

Population size reduction for the differential evolution algorithm
Janez Brest, Mirjam Sepesy Maučec, 2008, izvirni znanstveni članek

Opis: This paper studies the efficiency of a recently defined population-based direct global optimization method called Differential Evolution with self-adaptive control parameters. The original version uses fixed population size but a method for gradually reducing population size is proposed in this paper. It improves the efficiency and robustness of the algorithm and can be applied to any variant of a Differential Evolution algorithm. The proposed modification is tested on commonly used benchmark problems for unconstrained optimization and compared with other optimization methods such as Evolutionary Algorithms and Evolution Strategies.
Ključne besede: differential evolution, control parameter, fitness function, global function optimization, self-adaptation, population size
Objavljeno: 01.06.2012; Ogledov: 1313; Prenosov: 73
URL Povezava na celotno besedilo

Performance comparison of self-adaptive and adaptive differential evolution algorithms
Janez Brest, Borko Bošković, Sašo Greiner, Viljem Žumer, Mirjam Sepesy Maučec, 2007, izvirni znanstveni članek

Opis: Differential evolution (DE) has been shown to be a simple, yet powerful, evolutionary algorithm for global optimization. for many real problems. Adaptation, especially self-adaptation, has been found to be highly beneficial for adjusting control parameters, especially when done without any user interaction. This paper presents differential evolution algorithms, whichuse different adaptive or self-adaptive mechanisms applied to the control parameters. Detailed performance comparisons of these algorithms on the benchmark functions are outlined.
Ključne besede: differential evolution, control parameter, fitness function, optimization, self-adaption
Objavljeno: 01.06.2012; Ogledov: 1347; Prenosov: 60
URL Povezava na celotno besedilo

Implementing activities within the framework of logistic and marketing functions and their influence on their level of integration
Darja Topolšek, 2010, izvirni znanstveni članek

Opis: Activities which are implemented in logistic and marketing function often intertwine or overlap in practice, what can often lead to double implementation. Within the framework of this article we will analyse the actual state of implementing activities in companies in correlation with the functional area. Logisticians often define integration within the frame of the aforementioned chain, yet they neglect the internal integration or the integration of particular departments or particular functions in the company. Defining internal integration and its level as well as the connection with the index of the actual implementation of activities is the basis of the research part of this article. The quantitative research part studies whether and to what extent the implementation of activities influences the level of internal integration between the logistic and marketing function. Research is based on quantitative analysis of results which were gained from the questionnaires and were filled out in Slovenian retail companies.
Ključne besede: logistic function, implementing activities, marketing function, internal integration, inter-functional relations
Objavljeno: 05.06.2012; Ogledov: 1069; Prenosov: 22
URL Povezava na celotno besedilo

Understanding the importance of internal integration and its implications for intercultural business communication
Darja Topolšek, Sara Orthaber, 2011, izvirni znanstveni članek

Opis: The extent to which relationships in organizations are co-operative depends on the level of internal integration between functional and departmental groups. These relationships become even more critical in international businesses as well as in geographically dislocated subsidiaries. Cultural characteristics and different factors which managr, facilitatr and/or hinder internal integration present the basis for studying internal integration of different functions. Therefore, the following paper discusses various theoriesof internal integration and its role in organizations. More specifically, it focuses on logistics and marketing functions and explores studies that have investigated and examined the levels of internal integration of logistics and marketing functions. With the objective to identify potential implications, high/low levels of internal integration may have on intercultural communication which occurs in international business practices, the most prominent cultural frameworks are presented to identify implications different levels of internal integration may have for intercultural communication, in particular between Slovenian companies and their foreign subsidiaries.
Ključne besede: internal integration, logistics function, marketing function, intercultural communication
Objavljeno: 05.06.2012; Ogledov: 1619; Prenosov: 13
URL Povezava na celotno besedilo

Iskanje izvedeno v 0.32 sek.
Na vrh
Logotipi partnerjev Univerza v Mariboru Univerza v Ljubljani Univerza na Primorskem Univerza v Novi Gorici