Programs and Communities

Hybrid system models - those devised from two or more disparate sub-system models - provide a number of benefits in terms of conceptualization, development, and assessment of dynamical systems. The decomposition approach helps to formulate complex interactions that are otherwise difficult or impractical to express. However, hybrid model development and usage can introduce complexity that emerges from the composition itself.

To improve assurance of model correctness, sub-systems using disparate modeling formalisms must be integrated above and beyond just the data and control level; their composition must have model specification and simulation execution aspects as well. Poly-formalism composition is one approach to composing models in this manner.

This dissertation describes a poly-formalism composition between a Discrete EVent System specification (DEVS) model and a Cellular Automata (CA) model types. These model specifications have been chosen for their broad applicability in important and emerging domains. An agent-environment domain exemplifies the composition approach. The inherent spatial relations within a CA make it well-suited for environmental representations. Similarly, the component-based nature of agents fits well within the hierarchical component structure of DEVS.

This composition employs the use of a third model, called an interaction model, that includes methods for integrating the two model types at a formalism level, at a systems architecture level, and at a model execution level. A prototype framework using DEVS for the agent model and GRASS for the environment has been developed and is described. Furthermore, this dissertation explains how the concepts of this composition approach are being applied to a real-world research project.

This dissertation expands the tool set modelers in computer science and other disciplines have in order to build hybrid system models, and provides an interaction model for an on-going research project. The concepts and models presented in this dissertation demonstrate the feasibility of composition between discrete-event agents and discrete-time cellular automata. Furthermore, it provides concepts and models that may be applied directly, or used by a modeler to devise compositions for other research efforts.

Background: Vaccine-preventable diseases significantly influence the health and academic success of college students. Despite the known negative impact of these diseases, vaccination rates routinely fall short of national goals and recommendations. Although vaccination decisions are complex, a recommendation from a health care provider is one of the key motivators for individuals receiving a vaccine. Motivational interviewing (MI), a counseling approach primarily used to address substance abuse, can be applied to other health-related behaviors.

Local Problem: Despite previous quality improvement efforts aimed at increasing vaccine rates for influenza, human papillomavirus (HPV), and meningitis B (MenB), vaccinations at large university health centers have been well below benchmarks set by Healthy People 2020.

Methods: This study was guided by the Theory of Planned Behavior and included MI training and regular reinforcement for health care providers to address vaccine hesitancy with college students.

Results: Influenza vaccination rates improved, but HPV vaccine rates remained stable and MenB vaccine rates decreased compared with the previous year. Clinicians demonstrated a significant increase in knowledge of MI techniques after a targeted educational intervention. Repeat measures indicate the potential for sustained improvement when ongoing reinforcement is provided.

Conclusion: MI can be an effective part of a strategy to increase vaccination rates.

Purpose: This project examined the effectiveness of an online educational module on basic Motivational Interviewing (MI) techniques for Nurse Practitioners (NPs) providing obesity management to middle-aged women.

Background: Middle-aged women experience distinct physiological and psychosocial factors that contribute to weight gain and make obesity management especially challenging. The evidence supports the use of motivational interviewing (MI) interventions as a highly effective approach to obesity management in combination with standard medical weight loss programs. Educating NPs that provide medical weight loss on basic MI counseling techniques is necessary to facilitate the use of this intervention.

Methods: NP providers at a group of seven medical weight loss clinics in the southwestern United States completed an online MI educational module that was developed for this project. The module content covered basic MI counseling techniques. MI knowledge was assessed using a 6-item pre/post-test. Participants completed an 8-item course evaluation to provide additional feedback.

Results: Ten of the 13 NPs eligible participated in the project. The overall response to the project was positive as demonstrated by high scores on the course evaluation. The average post-test knowledge scores increased after completion of the module, however no statistical significance was noted.

Conclusions: The basic MI education module was beneficial for NPs providing obesity management and future research should focus on developing standardized MI weight loss interventions.