System dynamics is a popular modeling technique which is widely used in the analysis and design of dynamic systems. It can be applied to complex social, managerial, economic, or ecological systems. It conveniently models interdependence, mutual interaction, information feedback, and circular causality. The NIAM (Nijssen’s Information Analysis Methodology) is a fact-based conceptual schema model...

The unsteady increase in using pharmaceutical opioids is a phenomenon that has existed in human societies for a long time. Furthermore, the ever-growing trend of addiction to opioids affects communities in various economic, social, and cultural aspects. Since abusing pharmaceutical opioids is a complex dynamic problem, it is extremely difficult to recognize the factors influencing this abuse. T...

The unsteady increase in using pharmaceutical opioids is a phenomenon that has existed in human societies for a long time. Furthermore, the ever-growing trend of addiction to opioids affects communities in various economic, social, and cultural aspects. Since abusing pharmaceutical opioids is a complex dynamic problem, it is extremely difficult to recognize the factors influencing this abuse. T...

OBJECTIVE To evaluate the complex dynamics involved in implementing electronic health information exchange (HIE) for public health reporting at a state health department, and to identify policy implications to inform similar implementations. MATERIALS AND METHODS Qualitative data were collected over 8 months from seven experts at New York State Department of Health who implemented web service...

Models for numerical simulations should be described in a coherent style. They are expected to have consistencies at the causal dependency level. However, System Dynamics causal loop diagrams can have inconsistencies. This diagram style’s arrows, concerning flow and stock relationships, can have the opposite direction of stock flow diagrams which can numerically simulate models. These inconsist...

Diagrammatic rules are developed for simplifying two-loop QED diagrams with propagators in a constant self-dual background field. This diagrammatic analysis, using dimensional regularization, is used to explain how the fully renormalized two-loop Euler-Heisenberg effective Lagrangian for QED in a self-dual background field is naturally expressed in terms of one-loop diagrams. The connection bet...

We determine the master integrals for vertex and propagator diagrams that appear in effective field theories containing heavy fields. The involve at least one line, standard lines include an arbitrary mass scale. evaluation is done analytically with modern techniques. employ methods of differential equations dimensional recurrence relations to evaluate said up two-loop order.