Near Optimal Channel Assignment for Interference Mitigation in Wireless Mesh Networks

In multi-radio multi-channel (MRMC) WMNs, interference alleviation is affected through several network design techniques e.g., channel assignment (CA), link scheduling, routing etc., intelligent CA schemes being the most effective tool for interference mitigation. CA in WMNs is an NP-Hard problem, and makes optimality a desired yet elusive goal in real-time deployments which are characterized by fast transmission and switching times and minimal end-to-end latency. The trade-off between optimal performance and minimal response times is often achieved through CA schemes that employ heuristics to propose efficient solutions. WMN configuration and physical layout are also crucial factors which decide network performance, and it has been demonstrated in numerous research works that rectangular/square grid WMNs outperform random or unplanned WMN deployments in terms of network capacity, latency, and network resilience. In this work, we propose a smart heuristic approach to devise a near-optimal CA algorithm for grid WMNs (NOCAG). We demonstrate the efficacy of NOCAG by evaluating its performance against the minimal-interference CA generated through a rudimentary brute-force technique (BFCA), for the same WMN configuration. We assess its ability to mitigate interference both, theoretically (through interference estimation metrics) and experimentally (by running rigorous simulations in NS-3). We demonstrate that the performance of NOCAG is almost as good as the BFCA, at a minimal computational overhead of O(n) compared to the exponential of BFCA

A Process Improvement Study on a Military System of Clinics to Manage Patient Demand and Resource Utilization Using Discrete-Event Simulation, Sensitivity Analysis, and Cost-Benefit Analysis

Inefficiencies in the healthcare system are a growing concern. Long wait-times are a concern at military clinics because it takes servicemembers away from performing their duties. Managing wait-times are particularly challenging due to frequent relocations of servicemembers and variable patient demands that are less likely to be experienced by civilian clinics. Military clinics must be capable to meet increasing demand when servicemembers require a Deployment Health Assessment; it also needs to be capable of handling an instantaneous surge of walk-ins when a medical incident occurs in the local area. It must be able to meet these demands in a fiscally austere environment. Existing research primarily focuses on stand-alone clinics, whereas this research takes a novel approach of examining a system of clinics, in which some resources are shared. This research evaluates the impacts of variable staffing levels on total wait-time for the system of clinics at baseline demand and when demand increases, using discrete-event simulation, sensitivity analysis, and cost-benefit analysis. This research finds misallocated resources; the wait-time of alternative systems are sensitive to deployment and medical incident demands; and hiring an optometrist while removing an occupational medicine doctor provides the highest savings in baseline, deployment, and medical incident demand environments

The Trajectory of Coping with Trauma: Meaning Making as a Factor in Determining the Trauma Outcome for Combat Veterans

Specific ways in which an individual makes meaning following a stressful life event have been conceptualized as contributing to the emergence of Posttraumatic Stress Disorder (PTSD). However, little is known about how meaning making impacts the trauma trajectory and how that transition affects the outcomes of PTSD, Posttraumatic Growth (PTG), or resiliency. In this study, 166 combat veterans nationwide completed self-report surveys that were analyzed using a multivariate Structural Equation Modeling (SEM) method to create a model of how PTSD, PTG, and resiliency are impacted based upon meaning making. The results suggest that following a stressful life event, individuals who maintain intact world beliefs are more likely to be resilient. Individuals who experience a shattering of their world beliefs are hypothesized to report symptoms of PTSD. Likewise, individuals who experience a shattering of world beliefs and engage in avoidance coping are more likely to experience PTSD. However, individuals who experience a shattering of world beliefs but then make meaning from their experience are more likely to report an experience of PTG. Limitations and future directions of this research are also discussed in relation to the field\u27s movement toward outlining factors that positively impact PTG following deployment

Dynamic fault tolerant grid workflow in the water threat management project

Achieving fault tolerance is an inevitable problem in distributed systems, with it becoming more challenging in decentralized, heterogeneous, and dynamic-environment systems such as a Grid. When deploying applications requires time-criticality, how to allocate resources for jobs in a fault-tolerant manner is an important issue for the delivery of the services. The Water Threat Management project is a research to find solutions for the contamination incidents problems in urban water distribution systems, and it involves the development of the cyberinfrastructure in a Grid environment. To handle such urgent events properly, the deployment of the system demands real-time processing without the failure. Our approach of integrating a fault-tolerant framework into a Water Threat Management system provides fault tolerance at the queuing stage rather than the job-execution stage by scheduling jobs in fault-tolerant ways. This includes the development of the batch queuing system in the Cyberaide Shell project. In addition, we present a dynamic workflow in the Water Threat Management system that can reduce the queue wait time in the changing environment

Survey on wireless technology trade-offs for the industrial internet of things

Aside from vast deployment cost reduction, Industrial Wireless Sensor and Actuator Networks (IWSAN) introduce a new level of industrial connectivity. Wireless connection of sensors and actuators in industrial environments not only enables wireless monitoring and actuation, it also enables coordination of production stages, connecting mobile robots and autonomous transport vehicles, as well as localization and tracking of assets. All these opportunities already inspired the development of many wireless technologies in an effort to fully enable Industry 4.0. However, different technologies significantly differ in performance and capabilities, none being capable of supporting all industrial use cases. When designing a network solution, one must be aware of the capabilities and the trade-offs that prospective technologies have. This paper evaluates the technologies potentially suitable for IWSAN solutions covering an entire industrial site with limited infrastructure cost and discusses their trade-offs in an effort to provide information for choosing the most suitable technology for the use case of interest. The comparative discussion presented in this paper aims to enable engineers to choose the most suitable wireless technology for their specific IWSAN deployment

National Aeronautics and Space Administration (NASA)/American Society for Engineering Education (ASEE) Summer Faculty Fellowship Program, 1989, volume 1

The 1989 Johnson Space Center (JSC) National Aeronautics and Space Administration (NASA)/American Society for Engineering Education (ASEE) Summer Faculty Fellowship Program was conducted by Texas A and M University and JSC. The 10-week program was operated under the auspices of the ASEE. The program at JSC, as well as the programs at other NASA Centers, was funded by the Office of University Affairs, NASA Headquarters, Washington, D.C. The objectives of the program, which began nationally in 1964 and at JSC in 1965, are: (1) to further the professional knowledge of qualified engineering and science faculty members; (2) to stimulate an exchange of ideas between participants and NASA; (3) to enrich and refresh the research and teaching activities of participants' institutions; and (4) to contribute to the research objective of the NASA Centers