1. The complexity of porous structure of building materialsMarko Samec, 2011, doktorska disertacija Opis: This thesis seeks to establish the link between the structure (in a topological sense) of porous space and charged particle dynamics in porous matter, specifically in constituent elements of sustainable building materials such as clay, cement and soil. The work done is a combination of experimental research and modelling of analysed data using advanced and expanded network models to model pore structure and generalized conductivity model. The main outcome of this doctoral thesis is the demonstration that there is a correlation between the large scale structure of the pore space and the properties of the motion of charged particles through the pore space. This was achieved by conducting two experiments: the structure of pore space of selected porous materials (soil samples, clays, cements, clay-cement mixtures) was investigated using state-of-the-art X-ray computed microtomography, while the dynamics of charged particles in the samples was probed using low-frequency dielectric spectroscopy. The research done and described in the thesis is directed towards the advancement of understanding the transport phenomena and the structure of porous media which is of paramount importance for solving problems in building physics dealing with moist transport in building's envelope, the building-ground interaction, and in transport of contaminants in the vicinity of the repositories where the transfer of moist through soil can be the source of contamination. Ključne besede: porous matter, clay-water system, hydrating cement, fractional dynamics, dielectric response, X-ray computed tomography, image analysis, complex network Objavljeno: 11.05.2011; Ogledov: 3129; Prenosov: 117 Celotno besedilo (34,69 MB) |
2. Encyclopedia of complexity and systems scienceslovar, enciklopedija, leksikon, priročnik, atlas, zemljevid Opis: Encyclopedia of Complexity and Systems Science provides an authoritative single source for understanding and applying the concepts of complexity theory together with the tools and measures for analyzing complex systems in all fields of science and engineering. The science and tools of complexity and systems science include theories of self-organization, complex systems, synergetics, dynamical systems, turbulence, catastrophes, instabilities, nonlinearity, stochastic processes, chaos, neural networks, cellular automata, adaptive systems, and genetic algorithms. Examples of near-term problems and major unknowns that can be approached through complexity and systems science include: The structure, history and future of the universe; the biological basis of consciousness; the integration of genomics, proteomics and bioinformatics as systems biology; human longevity limits; the limits of computing; sustainability of life on earth; predictability, dynamics and extent of earthquakes, hurricanes, tsunamis, and other natural disasters; the dynamics of turbulent flows; lasers or fluids in physics, microprocessor design; macromolecular assembly in chemistry and biophysics; brain functions in cognitive neuroscience; climate change; ecosystem management; traffic management; and business cycles. All these seemingly quite different kinds of structure formation have a number of important features and underlying structures in common. These deep structural similarities can be exploited to transfer analytical methods and understanding from one field to another. This unique work will extend the influence of complexity and system science to a much wider audience than has been possible to date. Ključne besede: cellular automata, complex networks, computational nanoscience, ecological complexity, ergodic theory, fractals, game theory, granular computing, graph theory, intelligent systems, perturbation theory, quantum information science, system dynamics, traffic management, chaos, climate modelling, complex systems, dynamical sistems, fuzzy theory systems, nonlinear systems, soft computing, stochastic processes, synergetics, self-organization, systems biology, systems science Objavljeno: 01.06.2012; Ogledov: 1261; Prenosov: 7 Celotno besedilo (0,00 KB) |
3. The wavelet transform for BEM computational fluid dynamicsJure Ravnik, Leopold Škerget, Matjaž Hriberšek, 2004, izvirni znanstveni članek Opis: A wavelet matrix compression technique was used to solve systems of linear equations resulting from BEM applied to fluid dynamics. The governing equations were written in velocity-vorticity formulation and solutions of the resulting systems of equations were obtained with and without wavelet matrix compression. A modification of the Haar wavelet transform, which can transformvectors of any size, is proposed. The threshold, used for making fully populated matrices sparse, was written as a product of a user defined factor and the average value of absolute matrix elements values. Numerical tests were performed to assert, that the error caused by wavelet compression depends linearly on the factor , while the dependence of the error on the share of thresholded elements in the system matrix is highly non-linear. The results also showed that the increasing non-linearity (higher Ra and Re numbervalues) limits the extent of compression. On the other hand, higher meshdensity enables higher compression ratios. Ključne besede: fluid mechanics, computational fluid dynamics, boundary element method, wavelet transform, linear systems of equations, velocity vorticity formulation, driven cavity, natural convection, system matrix compression Objavljeno: 01.06.2012; Ogledov: 1003; Prenosov: 6 Celotno besedilo (0,00 KB) |
4. Inventory cost consequences of variability demand process within a multi-echelon supply chainFrancisco Campuzano Bolarín, Andrej Lisec, Francisco Cruz Lario Esteban, 2008, izvirni znanstveni članek Opis: The bullwhip effect (Lee et al, 1997a) is a known supply chain phenomenon where small variations in end item demand create oscillations that amplify throughout the chain. Different price elasticity of demand influence different changes of demand when prices of items are changing on the time horizon. The variance of the orders at the end user placed on suppliers or on manufacturer increases with the orders flow upstream in the logistics chain. This creates harmful consequences in inventory levels and all kind of inventory costs that may affect added value of activities along the logistics chain and finally affect Net Present Value of all activities in the chain. Traditional model of dynamic supply chain structures is used for this particular study, based on the seminal work of Forrester Diagrams (Forrester 1961). Simulation platform for supply chain management at stochastic demand developed by Campuzano (2006) has been used. VENSIM Simulation Software was previously used for developing these supply chain dynamic models. In the development platform generalised supply chain models are constructed graphically and also analytically. Our study here is to get a dipper insight into the processes in a logistics chain, measuring the inventory cost consequences due to variability demand amplification. Ključne besede: bullwhip effect, demand amplification, logistic chain, system dynamics Objavljeno: 05.06.2012; Ogledov: 629; Prenosov: 4 Celotno besedilo (0,00 KB) |
5. Combustion of municipal solid waste for power productionFilip Kokalj, Niko Samec, 2013, samostojni znanstveni sestavek ali poglavje v monografski publikaciji Ključne besede: gospodarjenje z odpadki, zgorevanje, waste management, municipal solid waste, integrated waste management system, waste-to-energy, thermal treatment, waste-to-energy plant, computational fluid dynamics Objavljeno: 10.07.2015; Ogledov: 482; Prenosov: 9 Celotno besedilo (0,00 KB) |
6. System dynamics model for policy scenarios of organic farming developmentMiroljub Kljajić, Andrej Škraba, Črtomir Rozman, Jernej Prišenk, Karmen Pažek, 2012, izvirni znanstveni članek Opis: This paper presents the system dynamics of organic farming development in order to support decision making. the model seeks answers to strategic questions related to the level of organically utilized area, levels of production and crop selection in long-term dynamic context. The model will be used for simulation of different policy scenarious for organic farming and their imapct on economic and developmental parameters of organic production atan aggregate level. Using the model, several policy scenarios were performed. Ključne besede: organic farming, system dynamics, simulation, model Objavljeno: 10.07.2015; Ogledov: 423; Prenosov: 2 Celotno besedilo (350,71 KB) |
7. A methodology for improving strategic decisions in social systems with a lack of informationAndrej Škraba, Carlos A. Legna Verna, 2010, izvirni znanstveni članek Opis: The design of strategies for social systems requires the use of qualitative information owing to the fact that quantitative information can be insufficient to solve the problems involved. The information that the specialists and the decision makers obtain is often incomplete and unreliable. Nevertheless, leaders have to make strategic decisions despite these deficiencies which should be based on the formal models (Kljajić et al. 2000; Škraba et al, 2003; Škraba et al 2007).
This paper describes a methodology elaborated to design the strategy of the city of Santa Cruz (on the Canary Islands). It has two main sections: the elaboration of a qualitative model and the use of System Dynamics. We combine them in a way that allows mixing qualitative and quantitative information to achieve a better understanding of the structure of the region, to know the tendencies of the present scenario and to estimate of the effects of alternative strategic decisions. We have obtained these results working with scarce quantitative information. This methodology may be applied to any social systems with similar characteristics. Ključne besede: qualitative models, system dynamics, social strategies Objavljeno: 10.07.2015; Ogledov: 182; Prenosov: 5 Celotno besedilo (668,60 KB) |
8. Simulation based group learningVladislav Rajkovič, Miroljub Kljajić, Andrej Škraba, Mirjana Kljajić Borštnar, 2007, izvirni znanstveni članek Ključne besede: group decision, learning model, system dynamics, feedback, experiment design Objavljeno: 10.07.2015; Ogledov: 307; Prenosov: 4 Celotno besedilo (0,00 KB) |
9. The periodicity of the anticipative discrete demand-supply modelDavorin Kofjač, Črtomir Rozman, Andrej Škraba, 2006, izvirni znanstveni članek Ključne besede: cobweb, hiperincursivity, system dynamics, anticipative system, nonlinear system, Farey tree, chaos Objavljeno: 10.07.2015; Ogledov: 272; Prenosov: 2 Celotno besedilo (0,00 KB) |
10. Methodology of system dynamics for decision support in agricultureMiroljub Kljajić, Andrej Škraba, Črtomir Rozman, 2012, izvirni znanstveni članek Ključne besede: system dynamics, modelling, complex systems, decision assessment, system approach, agriculture Objavljeno: 30.12.2015; Ogledov: 291; Prenosov: 6 Celotno besedilo (0,00 KB) |