1. How to test the reliability of instruments used in mirotremor horizontal-to-vertical spectral ratio measurementsIzidor Tasič, Franc Runovc, 2010, izvirni znanstveni članek Opis: The reliability of a horizontal-to-vertical spectral ratio (HVSR) curve depends on the results obtained by a verified seismological system. Seismic microzonation provides the basis for a site-specific risk analysis and it can be evaluated using the microtremor HVSR method, where the data are recorded using modern seismological systems. Changes in the transfer function of seismological systems affect the HVSR curve and, consequently, also its interpretation, if these changes are not detected and taken into consideration while performing the microtremor spectral calculations. The reliability of the seismic microzonation performed by such a procedure becomes questionable. An algorithm is developed with a two references system, where the influence of the transfer function on the HVSR curve by the tested system can be evaluated without any a-priori knowledge regarding the transfer functions of any of the systems. This approach is applied to a Lennartz Le-3D/5s seismometer and to a TROMINO seismological system, where two Streckeisen STS2 seismometers are used as the reference systems. Ključne besede: seismic microzonation, horizontal-to-vertical spectral ratio method, ambient vibrations, microtremor, seismic system transfer function, reliability and calibration of seismic systems Objavljeno v DKUM: 11.06.2018; Ogledov: 808; Prenosov: 51 Celotno besedilo (201,91 KB) Gradivo ima več datotek! Več... |
2. Green's function for tangentialy loaded horizontaly layered half-spaceTomaž Pliberšek, Andrej Umek, 2008, izvirni znanstveni članek Opis: The topic of this paper is a novel evaluation of the integral representation of the surface Greenćs function for a layered half-space, loaded on its surface by a harmonic tangential point force. The equations of motions are reduced to wave equations by the introduction of wave potentials. The Hankel transform is applied to them and they are consecutively solved leading to the integral representation of surface displacements. They are consecutively evaluated by the proposed three step procedure. First the singularity is extracted. It is further noted that so obtained integrals, after suitably chosen branch cuts and analytic continuation of integrands are introduced, can be evaluated by contour integration for an arbitrary number of layers. They are, therefore, expressed by number of residues at the poles of integrand and the integrals along finite portions of the branch cuts. The latter ones can easily be evaluated to any desired accuracy leading to a closed form solution. Some numerical results corroborating the presented approach are given. Ključne besede: elastodynamics, elastic wave propagation, Green`s function, horizontaly layered half-space, horizontal point load Objavljeno v DKUM: 05.06.2018; Ogledov: 962; Prenosov: 76 Celotno besedilo (329,66 KB) Gradivo ima več datotek! Več... |
3. Innovative solution principles of wave problems in horizontaly layered mediasAndrej Štrukelj, Andrej Umek, Tomaž Pliberšek, 2006, izvirni znanstveni članek Opis: The paper presents engineeringly reasonable transformation of surface displacements of horizontally layered half-space. The latter shows in the half-space present types of waves. It is shown that surface waves are expressed through residuums in poles of the integrand and the volume waves are expressed as integrals along corresponding branch cuts. The singularity which always appears in the basic singular solution in elastodynamics is in this case exactly excluded. In the second part of the paper the behaviour of Stonely waves is investigated in greater detail. It is shown that in the case of layers of finite thickness their appearance and velocities depends not onlyon the material characteristics of neighbouring layers but also on their thickness. Ključne besede: geomechanics, horizontally layered halfspace, volume waves, surface waves, Green`s function, Stonely waves Objavljeno v DKUM: 17.05.2018; Ogledov: 1108; Prenosov: 56 Celotno besedilo (613,03 KB) Gradivo ima več datotek! Več... |
4. Green's function for an elastic layer loaded harmonically on its surfaceTomaž Pliberšek, Andrej Štrukelj, Andrej Umek, 2005, izvirni znanstveni članek Opis: The Green's function in surface displacement plays an important role in soil structure interaction. In evaluating the Green's function, several difficulties occur because it is formulated in the infinite integral form. This paper outlines a method of analyzing the steady-state dynamic response of an elastic layer subjected to general point load excitation. It is assumed that the load is applied at the surface. The application Hankel integral transform, to the governing differential equations and boundary conditions yields the response displacements at the surface in integral representation. It will be shown that these semi-infinite integrals can be reduced to the integral with the finite range of integration, which can be efficiently taken numerically. The numerical results are presented, which show the efficiency of the developed procedure. Ključne besede: civil engineering, geomechanics, soil-structure interaction, layered halfspace, Green's function, elastodynamics Objavljeno v DKUM: 15.05.2018; Ogledov: 1218; Prenosov: 83 Celotno besedilo (375,59 KB) Gradivo ima več datotek! Več... |
5. Representation of Boolean functions with ROBDDsAleš Časar, Robert Meolic, samostojni znanstveni sestavek ali poglavje v monografski publikaciji Opis: This paper describes data structures and algorithms for representation of Boolean functions with reduced ordered binary decision diagrams (ROBDDs). A hash table is used for quick search. Additional information about variables and functions is stored in binary trees. Manipulations on functions are based on a recursive algorithm of ITE operation. The primary goal of this article is describe programming technics needed to realize the idea. For the first time here recursive algorithms for composing functions and garbage collection with a formulae counter are presented. This is better than garbage collection in other known implementations. The results of the tests show that the described representation is very efficient in applications which operate with Boolean functions. Ključne besede: Reduced Ordered Binary Decision Diagram, Boolean function, logic functions, logic design verification, hash table Objavljeno v DKUM: 02.02.2018; Ogledov: 2034; Prenosov: 50 Celotno besedilo (323,32 KB) |
6. How public relations impact on a company's effectivenessDamjana Jerman, Goran Vukovič, Bruno Završnik, 2008, izvirni znanstveni članek Opis: The role of public relations is dealing with the identification of organization's strategic public and developing communications programs for building solid, open and trusting relations with them. Many companies have taken a limited view of the impact that public relations can have on company's overall effectiveness. This paper consists of two parts: the theoretical framework for the role of public relations in the overall effectiveness of the company and an empirical analysis based on the primary data collected. We classified and analyzed different public relations factors (i.e. factors related to managing and implementing public relations) that influences the effectiveness of the company. We explored the correlation between public relations and a company's effectiveness and argued that public relations factors play a critical role in that effectiveness. We used linear regression and we found a significant linier relationship between the independent variable (public relations) and the dependent variable (company effectiveness). Ključne besede: public relations, public relations function, company's effectiveness, strategy, public relations agency Objavljeno v DKUM: 30.11.2017; Ogledov: 978; Prenosov: 297 Celotno besedilo (469,21 KB) Gradivo ima več datotek! Več... |
7. Implementation aspects of a BDD package supporting general decision diagrams : Revisited slides of a lecture given at JKU Linz on September 19th 2016Robert Meolic, 2016, predavanje na tuji univerzi Opis: General decision diagram is a loose term for a superset of different types of decision diagrams - we are interested in joining BDDs, FDDs, and different types of suppressed DDs, e.g. ZBDDs. I will present: The current state of our BDD package Biddy (functionalities and details about the original implementation aspects). Our ideas for efficient implementation of ZBDDs (which could be used for all types of suppressed DDs).New type od decision diagrams called ZFDD (somehow symmetric to ZBDD). A rough draft about the implementation of a package supporting general decision diagrams. Ključne besede: Binary Decision Diagram, Zero-suppressed Binary Decision Diagram, Boolean function, Algorithm, BDD package, Biddy Objavljeno v DKUM: 26.10.2017; Ogledov: 2624; Prenosov: 103 Celotno besedilo (1,07 MB) |
8. Suitability of the double Langevin function for description of anhysteretic magnetization curves in NO and GO electrical steel gradesSimon Steentjes, Martin Petrun, G. Glehn, Drago Dolinar, Kay Hameyer, 2017, izvirni znanstveni članek Opis: This paper compares the match obtained using the classical Langevin function, the tanh function as well as a recently by the authors proposed double Langevin function with the measured anhysteretic magnetization curve of three different non-oriented electrical steel grades and one grain-oriented grade. Two standard non-oriented grades and a high-silicon grade (Si content of 6.5%) made by CVD are analyzed. An excellent match is obtained using the double Langevin function, whereas the classical solutions are less appropriate. Thereby, problems such as those due to propagation of approximation errors observed in hysteresis modeling can be bypassed. Ključne besede: polarization, magnetization measurement, magnetic materials, hysteresis models, Langevin function, electrical steel, saturation Objavljeno v DKUM: 03.08.2017; Ogledov: 922; Prenosov: 391 Celotno besedilo (652,05 KB) Gradivo ima več datotek! Več... |
9. Rigid body dynamics in optimization of the machine tool vibroisolationRadomir Slavković, Aleksandar Veg, Nedeljko Dučić, Nikola Slavković, Jelena Baralić, Ivan Milićević, 2015, izvirni znanstveni članek Opis: Modern design of the machine tool treats the suspending parts as a crucial element of the effective vibration isolation. Therefore the suspending items are specifically developed and subjected to extensive tests before being applied on real objects. These elements ensure accurate levelling and appropriate vibration damping. Usually selection of inadequate support element causes intensive disturbing effects in machining. The paper presents dynamics analysis of the machine tool suspended on flexible mountings. The overall analysis is conceived on a rigid body dynamics. This method enables selection of an optimal supporting configuration. Further on such an effective suspension design prevents a need for expensive monitoring of the dynamic characteristics of the mechanical system, i.e. machine tool and supports. The paper explores dynamics of a real, flexibly supported machine tool. Results are obtained with the assistance of the "SUPPORT" software. Finally the theoretical and computational statements are approved throughout extensive site measurements on the machine tool body with appropriate instrumentation. Ključne besede: dynamics analysis, experiment, machine tool, software, transfer function Objavljeno v DKUM: 12.07.2017; Ogledov: 765; Prenosov: 370 Celotno besedilo (2,13 MB) Gradivo ima več datotek! Več... |
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