1. Systems approach to tourismTadeja Jere Lazanski, 2017, izvirni znanstveni članek Opis: Background and Purpose: The complexity of the tourism system, as well as modelling in a frame of system dynamics, will be discussed in this paper. The phaenomenon of tourism, which possesses the typical properties of global and local organisations, will be presented as an open complex system with all its elements, and an optimal methodology to explain the relations among them. The approach we want to present is due to its transparency an excellent tool for searching systems solutions and serves also as a strategic decisionmaking assessment. We will present systems complexity and develop three models of a complex tourism system: the first one will present tourism as an open complex system with its elements, which operate inside of a tourism market area. The elements of this system present subsystems, which relations and interdependencies will be explained with two models: causalloop diagram and a simulation model in frame of systems dynamics.
Design/methodology/approach: Systems methodology will be shown as the appropriate one, when we discuss complex systems challenges. For illustration, systems approach and systems methodology will be applied to tourism models. With building a qualitative causalloop diagram we will describe the tourism system complexity in forms of system%s elements relations. Mutual influences among the elements will be presented with positive and negative loops, which forms circles of reinforcement and balance. This will help us to discuss the problem categorically. The final model will follow the causalloop diagram. This will be a simulation model in a frame of system dynamics as an illustration of the discussed methodology.
Results: The methodology offers the solution of effective and holistic promotion of complex tourism system transformation, which has the potential to go beyond the myth of sustainable tourism and create significant shifts in the approach and acting of the participants (elements of the system) involved. Systems approach brings to tourism and the society, in general, broader dimensions of thinking, the awareness interdependency, interconnectivity, and responsibility for the behaviour of a system, which can be observed by feedback loops.
Conclusions: Findings about meaningfulness of systems thinking presented in the paper, are rarely presented to tourism society systemically and with the aim of designing sustainable complex tourism system. They show new approach, systems awareness and teaches thinking %out of the box%. Consequently, the sustainable behaviour is achieved: tourism supply and demand meet on responsible base and they connect to responsible stakeholders. Ključne besede: systems approach, complexity, tourism system, modelling, system dynamics Objavljeno: 22.01.2018; Ogledov: 450; Prenosov: 103 Celotno besedilo (625,68 KB) Gradivo ima več datotek! Več...

2. Assessing the impact of prices fluctuation on demand distortion within a multiechelon supply chainFrancisco Campuzano Bolarín, Antonio Guillamón Frutos, Andrej Lisec, 2011, pregledni znanstveni članek Opis: Price fluctuation is a practice commonly used by companies to stimulate demand and a main cause of the Bullwhip effect. Assuming a staggered step demand pattern that responds elastically to retailer’s price fluctuation, and by using a supply chain management dynamic model, we will analyse the impact of these fluctuations on the variability of the orders placed along a traditional multilevel supply chain. Subsequently, the results obtained will serve to propose a forecasting model enabling to calculate the potential variability of orders placed by each echelon on the basis of the price pattern used. Finally, under the hypothesis of an environment of collaboration between the different members of the chain, we propose a predictive model that makes it possible to quantify the distortion of the orders generated by each level. Ključne besede: bullwhip effect, systems dynamics, price fluctuation, supply chain management Objavljeno: 01.06.2017; Ogledov: 603; Prenosov: 268 Celotno besedilo (560,46 KB) Gradivo ima več datotek! Več...

3. 
4. Statistical Properties of Timedependent SystemsDiego Fregolente Mendes De Oliveira, 2012, doktorska disertacija Opis: In the dissertation I have dealt with timedependent (nonautonomous) systems,
the conservative (Hamiltonian) as well as dissipative, and investigated their dynamical
and statistical properties. In conservative (Hamiltonian) timedependent systems the
energy is not conserved, whilst the Liouville theorem about the conservation of the phase
space volume still applies. We are interested to know, whether the system can gain
energy, and whether this energy can grow unbounded, up to infinity, and we are
interested in the system's behaviour in the mean, as well as its statistical
properties. An example of such a system goes back to the 1940s, when Fermi proposed
the acceleration of cosmic rays (in the first place protons) upon the collisions
with moving magnetic domains in the interstellar medium of our Galaxy,
and in other galaxies. He then proposed a simple mechanical onedimensional model,
the socalled FermiUlam Model (FUM), where a point particle is moving between two
rigid walls, one being at rest and the other one oscillating. If the oscillation
is periodic and smooth, it turned out in a nontrivial way, which is, in the
modern era of understanding the chaotic dynamical systems, well understood,
namely that the unbounded increasing of the energy (the socalled Fermi
acceleration) is not possible, due to the barriers in form of invariant tori,
which partition the phase space into regions, between which the transitions are
not possible. The research has then been extended to other simple dyanamical
systems, which have complex dynamics. The first was socalled bouncer model,
in which a point particle bounces off the oscillating platform in a gravitational
field. In this simple system the Fermi acceleration is possible. Later
the research was directed towards twodimensional billiard systems. It turned
out that the Fermi acceleration is possible in all such systems, which are at least
partially chaotic (of the mixed type), or even in a system that is integrable
as static, namely in case of the elliptic billiard. (The circle billiard
is an exception, because it is always integrable, as the angular momentum
is conserved even in timedependent case.) The study of timedependent systems
has developed strongly worldwide around the 1990s, in particular in 2000s,
and became one of the central topics in nonlinear dynamics. It turned out,
quite generally, but formal and implicit, in the sense of mathematical
existence theorems, that in nonautonomous Hamilton systems the energy can
grow unbounded, meaning that the system ``pumps" the energy from the environment
with which it interacts. There are many open questions: how does the energy
increase with time, in particular in the mean of some representative ensemble
of initial conditions (typically the phase space of twodimensional timedependent
billiards is fourdimensional.) It turned out that almost everywhere the power laws
apply, empirically, based on the numerical calculations, but with various
acceleration exponents. If the Fermi acceleration is not posssible, like e.g.
in the FUM, due to the invariant tori, then after a certain time of acceleration
stage the crossover into the regime of saturation takes place, whose
characteristics also follow the power laws. One of the central themes in
the dissertation is the study of these power laws, their critical exponents,
analytical relationships among them, using the scaling analysis
(Leonel, McClintock and Silva, Phys. Rev. Lett. 2004). Furthermore, the central
theme is the question, what happens, if, in a nonautonomous Hamilton system
which exhibits Fermi acceleration, we introduce dissipation, either
at the collisions with the walls (collisional dissipation) or
during the free motion (inflight dissipation, due to the viscosity
of the fluid or the drag force etc.). Dissipation typically transforms
the periodic points into point attractors and chaotic components into
chaotic attractors. The Fermi acceleration is always suppressed.
We are interested in the phase portraits of Ključne besede: nonlinear dynamics, dynamical systems, conservative and dissipative
systems, timedependent systems, Fermi acceleration, billiards, kicked systems, chaos, chaotic and periodic attractors, bifurcations, boundary crisis Objavljeno: 19.09.2012; Ogledov: 2356; Prenosov: 101 Celotno besedilo (16,09 MB) 
5. Nonlinear time series analysis of the human electrocardiogramMatjaž Perc, 2005, strokovni članek Opis: We analyse the human electrocardiogram with simple nonlinear time series analysis methods that are appropriate for graduate as well as undergraduate courses. In particular, attention is devoted to the notions of determinism and stationarity in physiological data. We emphasize that methods of nonlinear time series analysis can be successfully applied only if the studied data set originates from a deterministic stationary system. After positively establishing the presence of determinism and stationarity in the studied electrocardiogram, we calculate the maximal Lyapunov exponent, thus providing interesting insights into the dynamics of the human heart. Moreover, to facilitate interest and enable the integration of nonlinear time series analysis methods into the curriculum at an early stage of the educational process, we also provide userfriendly programs for each implemented method. Ključne besede: dynamic systems, chaotic systems, nonlinear dynamics, electrocardiogram, human electrocardiogram, nonlinear analyses Objavljeno: 07.06.2012; Ogledov: 1838; Prenosov: 73 Povezava na celotno besedilo 
6. Visualizing the attraction of strange attractorsMatjaž Perc, 2005, strokovni članek Opis: We describe a simple new method that provides instructive insights into the dynamics of chaotic timecontinuous systems that yield strange attractors as solutions in the phase space. In particular, we show that the norm of the vector field component that is orthogonal to the trajectory is an excellent quantity for visualizing the attraction of strange attractors, thus promoting the understanding of their formation and overall structure. Furthermore, based on the existence of zero orthogonal field strengths in planes that form lowdimensional strange attractors, we also provide an innovative explanation for the origin of chaotic behaviour. For instructive purposes, we first apply the method to a simple limit cycle attractor, and then analyse two paradigmatic mathematical models for classical timecontinuous chaos. To facilitate the use of our method in graduate as well as undergraduate courses, we also provide userfriendly programs in which the presented theory is implemented. Ključne besede: dynamic systems, chaotic systems, nonlinear dynamics, attractors, strange attractors Objavljeno: 07.06.2012; Ogledov: 1696; Prenosov: 56 Povezava na celotno besedilo 
7. Thoughts out of noiseMatjaž Perc, 2006, izvirni znanstveni članek Opis: We study the effects of additive Gaussian noise on the behaviour of a simple spatially extended system, which is locally modelled by a nonlinear twodimensional iterated map describing neuronal dynamics. In particular, we focus on the ability of noise to induce spatially ordered patterns, i. e. the socalled noiseinduced pattern formation. For intermediate noise intensities, the spatially extended system exhibits ordered circular waves, thereby clearly manifesting the constructive role of random perturbations. The emergence of observed noiseinduced patterns is explained with simple arguments that are obtained by analysing the typical spatial scale of patterns evoked by various diffusion coefficients. Since discretetime systems are straightforward to implement and require modest computational capabilities, the present study describes one of the most fascinating and visually compelling examples of noiseinduced selforganization in nonlinear systems in an accessible way for graduate or even advanced undergraduate students attending a nonlinear dynamics course. Ključne besede: dynamic systems, chaotic systems, nonlinear dynamics, nonlinear systems, noise, nonlinear analyses Objavljeno: 07.06.2012; Ogledov: 1071; Prenosov: 27 Povezava na celotno besedilo 
8. Proximity to periodic windows in bifurcation diagrams as a gateway to coherence resonance in chaotic systemsMarko Gosak, Matjaž Perc, 2007, izvirni znanstveni članek Opis: We show that chaotic states situated in the proximity of periodic windows in bifurcation diagrams are eligible for the observation of coherence resonance. In particular, additive Gaussian noise of appropriate intensity can enhance the temporal order in such chaotic states in a resonant manner. Results obtained for the logistic map and the Lorenz equations suggest that the presented mechanism of coherence resonance is valid beyond particularities of individual systems. We attribute the findings to the increasing attraction of imminent periodic orbits and the ability of noise to anticipate their existence and use a modified wavelet analysis to support our arguments. Ključne besede: chaotic systems, spatial resonance, coherence resonance, nonlinear systems, noise, spatial dynamics, mathematical models, bifurcation diagrame Objavljeno: 07.06.2012; Ogledov: 1693; Prenosov: 96 Povezava na celotno besedilo 
9. Transition from Gaussian to Levy distributions of stochastic payoff variations in the spatial prisoner's dilemma gameMatjaž Perc, 2007, izvirni znanstveni članek Opis: We study the impact of stochastic payoff variations with different distributions on the evolution of cooperation in the spatial prisoner's dilemma game. We find that Gaussiandistributed payoff variations are most successful in promoting cooperation irrespective of the temptation to defect. In particular, the facilitative effect of noise on the evolution of cooperation decreases steadily as the frequency of rare events increases. Findings are explained via an analysis of local payoff ranking violations. The relevance of results for economics and sociology is discussed. Ključne besede: stochastic systems, spatial resonance, stochastic payoff variations, nonlinear systems, noise, spatial dynamics, mathematical models, prisoner's dilemma Objavljeno: 07.06.2012; Ogledov: 1481; Prenosov: 74 Povezava na celotno besedilo 
10. Spatial coherence resonance in neuronal media with discrete local dynamicsMatjaž Perc, 2006, izvirni znanstveni članek Opis: We study effects of spatiotemporal additive noise on the spatial dynamics of excitable neuronal media that is locally modelled by a twodimensional map. We focus on the ability of noise to enhance a particular spatial frequency of the media in a resonant manner. We show that there exists an optimal noise intensity for which the inherent spatial periodicity of the media is resonantly pronounced, thus marking the existence of spatial coherence resonance in the studied system. Additionally, results are discussed in view of their possible biological importance. Ključne besede: physics, complex systems, dynamical systems, noise, spatial dynamics, chaos, chaotic systems, chaos control, resonance Objavljeno: 07.06.2012; Ogledov: 1649; Prenosov: 92 Povezava na celotno besedilo 