This paper investigates the diffusion of system dynamics as research paradigm. It deals with the question whether the diffusion of system dynamics is influenced by network externalities. Assuming the existence of such network externalities the so called penguin and bandwagon effect must be considered regarding the diffusion. Based on a system dynamics model considering network externalities lev...

background and purpose : there has been no report in which preoperative evaluation of adc for prediction of post therapeutic outcome was presented. the aim of our study was to retrospectively evaluation the use of the apparent diffusion coefficient (adc) for the prediction of malignancy and the outcome of malignant astrocytic tumors. methods: we reviewed mri of 26 male and 14 female patients wi...

Achieving the Millennium Development Goals has proven to be a real challenge. Providing evidence on cost-effective interventions did not prove to be sufficient to secure the trust of national authorities, health care providers and patients. Introducing change in a health system requires a good understanding of the relationships between the actors of the system. Social network analysis can provi...

Abstract The problem of dynamic reconstruction of an unknown coordinate in a system of nonlinear equations describing the process of innovation diffusion from results of observations of phase state is considered. An algorithm for solving this problem, which is stable with respect to informational noises and computational errors, is suggested. The algorithm is based on the principle of auxiliary...

In this paper we describe G/G/R+s multi- repairmen machining system with balking. The system consists of M operating machines, S spare machines, R permanent and s additional repairmen. Assuming the discrete flow of machines by continuous one, the diffusion approximation technique for the machine repair system has developed. The system will be in normal working mode if there is M operating machi...

background hepatic fibrosis is a typical complication of chronic liver diseases resulting in cirrhosis that remains a major public health problem worldwide. liver biopsy is currently the gold standard for diagnosing and staging hepatic fibrosis. percutaneous liver biopsy; however, is an invasive procedure with risks of complications. therefore, there is need for alternative non-invasive techniq...

The present paper is aimed to study an exact analysis of the free vibrations of a simply supported, homogeneous, transversely isotropic, cylindrical panel based on three-dimensional generalized theories of thermoelastic diffusion. After applying the displacement potential functions in the basic governing equations of generalized thermoelastic diffusion, it is noticed that a purely transverse mo...

The machine repair problem with spares and additional repairman is analyzed. The interfailure and repair times of the units are general identical and independently distributed. The failure and repair rates are assumed to be state dependent. Using diffusion approximation technique, we obtain the queue size distribution under steady state. The average number of failed units, average number of ope...

The Cellular Automata method has been used to simulate the pattern formation of the Schlögl model as a bistable Reaction-Diffusion System. Both microscopic and macroscopic Cellular Automata approaches have been considered and two different methods for obtaining the probabilities in the microscopic approach have been mentioned. The results show the tendency of the system towards the more sta...

We consider a system of coupled reaction-diffusion equations that models the interaction between multiple types of chemical species, particularly the interaction between one messenger RNA and different types of non-coding microRNAs in biological cells. We construct various modeling systems with different levels of complexity for the reaction, nonlinear diffusion, and coupled reaction and diffus...