System dynamics model Dotaz Zobrazit nápovědu
BACKGROUND: Alzheimer's disease is one of the most common mental illnesses. It is posited that more than 25% of the population is affected by some mental disease during their lifetime. Treatment of each patient draws resources from the economy concerned. Therefore, it is important to quantify the potential economic impact. METHODS: Agent-based, system dynamics and numerical approaches to dynamic modeling of the population of the European Union and its patients with Alzheimer's disease are presented in this article. Simulations, their characteristics, and the results from different modeling tools are compared. RESULTS: The results of these approaches are compared with EU population growth predictions from the statistical office of the EU by Eurostat. The methodology of a creation of the models is described and all three modeling approaches are compared. The suitability of each modeling approach for the population modeling is discussed. CONCLUSION: In this case study, all three approaches gave us the results corresponding with the EU population prediction. Moreover, we were able to predict the number of patients with AD and, based on the modeling method, we were also able to monitor different characteristics of the population.
- Klíčová slova
- Alzheimer’s disease, agent-based model, numerical model, population modeling, population prediction, system dynamics.,
- MeSH
- Alzheimerova nemoc diagnóza epidemiologie MeSH
- biologické modely MeSH
- lidé MeSH
- systémová analýza * MeSH
- teoretické modely * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
INTRODUCTION: Alzheimer's disease (AD) is a slowly progressing neurodegenerative brain disease with irreversible brain effects; it is the most common cause of dementia. With increasing age, the probability of suffering from AD increases. In this research, population growth of the European Union (EU) until the year 2080 and the number of patients with AD are modeled. AIM: The aim of this research is to predict the spread of AD in the EU population until year 2080 using a computer simulation. METHODS: For the simulation of the EU population and the occurrence of AD in this population, a system dynamics modeling approach has been used. System dynamics is a useful and effective method for the investigation of complex social systems. Over the past decades, its applicability has been demonstrated in a wide variety of applications. In this research, this method has been used to investigate the growth of the EU population and predict the number of patients with AD. The model has been calibrated on the population prediction data created by Eurostat. RESULTS: Based on data from Eurostat, the EU population until year 2080 has been modeled. In 2013, the population of the EU was 508 million and the number of patients with AD was 7.5 million. Based on the prediction, in 2040, the population of the EU will be 524 million and the number of patients with AD will be 13.1 million. By the year 2080, the EU population will be 520 million and the number of patients with AD will be 13.7 million. CONCLUSION: System dynamics modeling approach has been used for the prediction of the number of patients with AD in the EU population till the year 2080. These results can be used to determine the economic burden of the treatment of these patients. With different input data, the simulation can be used also for the different regions as well as for different noncontagious disease predictions.
- Klíčová slova
- Alzheimer’s disease, population modeling, prediction model, system dynamics,
- Publikační typ
- časopisecké články MeSH
We propose a new epidemiological model, based on the classical SIR model, taking additionally into account a switching prevention strategy. The model has two distinct thresholds that determine the beginning and the end of an intervention and two different transmission rates. We study the global dynamics of the proposed two-dimensional model.
- Klíčová slova
- Disease prevention, Endemic equilibrium, Public intervention, SIR model dynamics, Switching transmission rate,
- MeSH
- biologické modely * MeSH
- epidemie prevence a kontrola statistika a číselné údaje MeSH
- infekční nemoci epidemiologie přenos MeSH
- kontrola infekčních nemocí statistika a číselné údaje MeSH
- lidé MeSH
- lineární modely MeSH
- matematické pojmy MeSH
- počítačová simulace MeSH
- systémová biologie MeSH
- vakcinace statistika a číselné údaje MeSH
- výpočetní biologie MeSH
- základní reprodukční číslo prevence a kontrola statistika a číselné údaje MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The objective of this paper is the study of the dynamical properties analysis of an original specification of the classical Cournot heterogeneous model with optimal response; specifically, a new approach that considers ordinal utility instead of cardinal monetary amounts is proposed where the classical decision of quantity is disentangled from the decision on imitation. The analysis is performed by means of bifurcation diagrams, the 0-1 test for chaos, power spectral density, histograms, and trajectory analysis. For this purpose, a new perturbation parameter ε of the initial condition is introduced, and together with the intensity of choice parameter β determining the share of responders vs imitators, the system is researched. Depending on ε and β, extreme reach dynamics, and coexisting attractors, periodic and chaotic trajectories are investigated through massive simulations. Those dynamics represent alternation between stability, cycles and chaos in the market. As the dynamics are completely endogenous, it means that swings in economy are intrinsic to the system and that they may persist unless controlled.
- MeSH
- nelineární dynamika * MeSH
- Publikační typ
- časopisecké články MeSH
The structured population LPA model is studied. The model describes flour beetle (Tribolium) population dynamics of four stage populations: eggs, larvae, pupae and adults with cannibalism between these stages. We concentrate on the case of non-zero cannibalistic rates of adults on eggs and adults on pupae and no cannibalism of larvae on eggs, but the results can be numerically continued to non-zero cannibalism of larvae on eggs. In this article two-parameter bifurcations in LPA model are analysed. Various stable and unstable invariant sets are found, different types of hysteresis are presented and abrupt changes in dynamics are simulated to explain the complicated way the system behaves near two-parameter bifurcation manifolds. The connections between strong 1:2 resonance and Chenciner bifurcations are presented as well as their very significant consequences to the dynamics of the Tribolium population. The hysteresis phenomena described is a generic phenomenon nearby the Chenciner bifurcation or the cusp bifurcation of the loop.
- Klíčová slova
- Chenciner bifurcation, LPA model, Population dynamics, Strong 1:2 resonance, Two-parameter bifurcations,
- MeSH
- biologické modely * MeSH
- chování zvířat MeSH
- kanibalismus MeSH
- matematické pojmy MeSH
- nelineární dynamika MeSH
- populační dynamika statistika a číselné údaje MeSH
- Tribolium růst a vývoj fyziologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
This study delves into the intricate dynamics of tourism-induced water pollution through a systematic literature review, aiming to unravel complexities using a system dynamics (SD) modeling approach coupled with the PRISMA analysis methodology. Employing a comprehensive PRISMA analysis of 68 pertinent articles, the study establishes a metamodel for comprehending plastic pollution in water ecosystems resulting from tourism. The methodology emphasizes economic and environmental dimensions, causal conditions, and interventions, with a specific focus on the role of Information and Communication Technology (ICT). The results highlight integrated strategies as crucial in mitigating tourism-induced water pollution. These strategies advocate for the incorporation of environmental conservation and sustainable management practices. The study underlines the pivotal role of environmental education, awareness, and investments in protection as effective interventions. The findings offer valuable insights for policymakers and stakeholders in the tourism industry, emphasizing the necessity for proactive planning and management. The study advocates for knowledge-based decision-making to optimize tourism's environmental impacts and underscores the significance of quick and flexible responses to environmental challenges.
- Klíčová slova
- Microplastics, Plastics, System dynamics models, Tourism, Water pollution,
- Publikační typ
- časopisecké články MeSH
The current interest in systems biology is to gain a better understanding of how the complex dynamic behaviour of the cell emerges from mutual interactions of molecular species. When solving such a nontrivial goal, biological data have to be necessarily integrated with mathematical modelling and computer analysis. Since the key aspect of biological modelling is based on unifying several kinds of data captured in terms of large-scale biological networks, scalable and automatized methods are necessary to obtain novel predictions and understanding. In this review, we provide a brief description of the tool DiVinE adapted for automatized analysis of biological systems dynamics. The tool employs high-performance computing techniques to enable analysis of large models.
In the previous two articles (Theor. Popul. Biol. 49 (1996) 265-290; 55 (1999) 111-126), the population dynamics resulting from a two-prey-one-predator system with adaptive predators was studied. In these articles, predators followed the predictions of optimal foraging theory. Analysis of that system was hindered by the incorporation of the logistic description of prey growth. In particular, because prey self-regulation dependence is a strong stabilizing mechanism, the effects of optimal foraging could not be easily separated from the effects of bottom-up control of prey growth on species coexistence. In this article, we analyze two models. The first model assumes the exponential growth of both prey types while the second model assumes the exponential growth of the preferred prey type and the logistic growth of the alternative prey type. This permits the effect of adaptive foraging on two-prey-predator food webs to be addressed. We show that optimal foraging reduces apparent competition between the two prey types, promotes species coexistence, and leads to multiple attractors.
- MeSH
- ekosystém MeSH
- lidé MeSH
- populační dynamika * MeSH
- predátorské chování * MeSH
- teoretické modely * MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
An important problem in current computational systems biology is to analyze models of biological systems dynamics under parameter uncertainty. This paper presents a novel algorithm for parameter synthesis based on parallel model checking. The algorithm is conceptually universal with respect to the modeling approach employed. We introduce the algorithm, show its scalability, and examine its applicability on several biological models.
The Joint Model of the Contractile System of Muscle is a theoretical construction and the question is whether it may express adequately some aspects of the biological original. In addition to the previous results which presented preliminary calculations, simulation experiments have been performed with a dynamic version of the model. The relations found between the variables studied (length, shortening velocity, isotonic contraction load, shortening heat production rate and excess of effective activity), did not essentially differ from those established by preliminary calculations; the choice of appropriate parameter values and the introduction of some additional features in the system made it possible to obtain a better approximation of relations known from measurements on the biological object. The model discloses some relevant general aspects of the contractile system of "independent" generators of force and thus contributes to a specification of the relationships between molecular and macroscopic levels of contraction phenomena. Future development or correction of the concepts under consideration depend on more suitable empirical data and further simulation experiments.
