because of electricity subsidies, electricity price in iran is much lower than its real value, and the growth of electricity demand is much more than its rational rate, which in turn implies ever increasing investment in the electricity section by the government. therefore, the recent government policies are based on elimination of electricity subsidies, followed by commissioning complete elect...

background: nowadays the eutrophication of water bodies is enhanced due to discharge of effluents and runoffs. therefore, there is a demand for the management of natural and artificial lakes to prevent or postpone this problem. lakes eutrophication is a complex process. therefore computerized models are very important tools to describe this process. although there are several models for this, b...

conclusions the results indicated that the model, compared with other models, was user-friendly and the desired results were obtained by a minimal data. materials and methods the current paper developed a process model. first, a sketch of nitrate and ammonia storage, their specifications and parameters were set out and created on a page, and then, mathematical relations of each process were set...

This paper investigates the advantages of using Systems Thinking and System Dynamics in the analysis of health care systems. It demonstrates that the disappointing results observed in health care management are due to a lack of adoption of systemic methods to study these systems. The paper portrays the consequences and causes of policy resistance in health care systems and how they can be overc...

Model analysis in system dynamics (SD) entails articulating exactly how the structure of circular, feedback relations among variables in a system determines its performance through time. This article combines disruptive innovation (DI) theory with SD to show the use and benefits of model analysis with the pathway participation metric (PPM), implemented in the Digest® software. The model replica...

BACKGROUND In order to facilitate the collaborative design, system dynamics (SD) with a group modelling approach was used in the early stages of planning a new stroke unit. During six workshops a SD model was created in a multiprofessional group. AIM To explore to which extent and how the use of system dynamics contributed to the collaborative design process. METHOD A case study was conduct...

System Dynamics’ (SD) main aim is to study dynamic behavior of systems based on causal relations. The other purpose of the science is to design policies, both in initial values and causal relation, to change system behavior as we desire. Especially we are interested in making system’s behavior a convergent one. Although now SD is mainly used in situations of single policy maker, there are major...

In this research we concentrate on developing a system dynamics (SD) model for county cycle economy research. We analyze the causality of the county cycle economy system, set up a set of formulations based on the use of group method of data handling (GMDH), then build a system dynamics model to simulate the evolving process of this county system. Through this model and simulation, we get a seri...

We present SD-SQL Server, a prototype scalable distributed database system. It let a relational table to grow over new storage nodes invisibly to the application. The evolution uses splits dynamically generating a distributed range partitioning of the table. The splits avoid the reorganization of a growing database, necessary for the current DBMSs and a headache for the administrators. We illus...

System Dynamics modeling and Discrete Event Simulation both can be used to model corporate business decisions. However, there seems to be little dialog between the two communities of modelers. For instance, at the recent WinterSim simulation conference in Washington, DC, there were no presentations of System Dynamics models. Discussions held by the author with a number of practitioners in each ...