An SPICE compatible model for multiple coupled nonuniform lossless transmission lines (TL's) is presented. The method of the modeling is based on the steplines approximation of the nonuniform TLs and quasi-TEM assumptions. Using steplines approximation the system of coupled nonuniform TLs is subdivided into arbitrary large number of coupled uniform lines (steplines) with different characteristi...

in this paper mathematical extensions and generalizations of the pearl-reed model for'growth with saturation are discussed. the derived differential equation are of bernoulli and riccati type that owing to their special forms could be explicitely integrated resulting in closed form solutions. the asymptotic bahaviour of the system in each case is briefly examined and the results are compar...

this paper provides a fuzzy based decision support system (dss) for risk analysis in e-tourism ( electronic tourism ) investment. in general term, e-tourism is the use of information and communication technology (ict) in tourism which may allow operating tourism in least variable cost, least time and increased work efficiency. it is worth noting that there are many factors that affect the deve...

data envelopment analysis (dea) is a managerial powerful tool for assess the performance of decision making units (dmus). nowadays, multi-objective dea models are an attractive technique for evaluation quantity and quality aspects of performance analysis. but these models are in static. in this paper, we want to present a proposed fuzzy dynamic multi-objective dea model in which data are changi...

Abstract Critical infrastructure (CIs) such as power grids link a plethora of physical components from many different vendors to the software systems that control them. These are constantly threatened by sophisticated cyber attacks. The need improve cybersecurity CIs, through holistic system modeling and vulnerability analysis, cannot be overstated. This is challenging since CI incorporates com...

in more recent years, it has become increasingly recognized that r&d; (research and development) is a key driver of economic growth, a source of innovation and change, and as such stimulates improvements in productivity and economic competitiveness. it is closely associated with knowledge and flexibility, two factors that have gained new significance as a source of competitiveness in an increas...

the primary focus of the present study is to review organization analysis models from the standpoint of marketing and to propose an appropriate model for information centers and entities. a detailed literature review is made concerning marketing concepts, principles and services with respect to information organizations. the second stage deals with review and study of information entities, thei...

this paper is concerned with global analysis of a delay sveir epidemiological model in a population of varying size. by using lyapunov stability method and lasalle’s invariance principle for delay systems, we prove that when there is no endemic equilibrium, the disease free equilibrium is globally asymptotically stable, otherwise the endemic equilibrium is globally stable.