64,994 research outputs found

    A Hierachical Evolutionary Algorithm for Multiobjective Optimization in IMRT

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    Purpose: Current inverse planning methods for IMRT are limited because they are not designed to explore the trade-offs between the competing objectives between the tumor and normal tissues. Our goal was to develop an efficient multiobjective optimization algorithm that was flexible enough to handle any form of objective function and that resulted in a set of Pareto optimal plans. Methods: We developed a hierarchical evolutionary multiobjective algorithm designed to quickly generate a diverse Pareto optimal set of IMRT plans that meet all clinical constraints and reflect the trade-offs in the plans. The top level of the hierarchical algorithm is a multiobjective evolutionary algorithm (MOEA). The genes of the individuals generated in the MOEA are the parameters that define the penalty function minimized during an accelerated deterministic IMRT optimization that represents the bottom level of the hierarchy. The MOEA incorporates clinical criteria to restrict the search space through protocol objectives and then uses Pareto optimality among the fitness objectives to select individuals. Results: Acceleration techniques implemented on both levels of the hierarchical algorithm resulted in short, practical runtimes for optimizations. The MOEA improvements were evaluated for example prostate cases with one target and two OARs. The modified MOEA dominated 11.3% of plans using a standard genetic algorithm package. By implementing domination advantage and protocol objectives, small diverse populations of clinically acceptable plans that were only dominated 0.2% by the Pareto front could be generated in a fraction of an hour. Conclusions: Our MOEA produces a diverse Pareto optimal set of plans that meet all dosimetric protocol criteria in a feasible amount of time. It optimizes not only beamlet intensities but also objective function parameters on a patient-specific basis

    The future of laboratory medicine - A 2014 perspective.

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    Predicting the future is a difficult task. Not surprisingly, there are many examples and assumptions that have proved to be wrong. This review surveys the many predictions, beginning in 1887, about the future of laboratory medicine and its sub-specialties such as clinical chemistry and molecular pathology. It provides a commentary on the accuracy of the predictions and offers opinions on emerging technologies, economic factors and social developments that may play a role in shaping the future of laboratory medicine

    The Promise of Health Information Technology: Ensuring that Florida's Children Benefit

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    Substantial policy interest in supporting the adoption of Health Information Technology (HIT) by the public and private sectors over the last 5 -- 7 years, was spurred in particular by the release of multiple Institute of Medicine reports documenting the widespread occurrence of medical errors and poor quality of care (Institute of Medicine, 1999 & 2001). However, efforts to focus on issues unique to children's health have been left out of many of initiatives. The purpose of this report is to identify strategies that can be taken by public and private entities to promote the use of HIT among providers who serve children in Florida

    Urban pollution and ecosystem services

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    Urban pollutants can degrade and inhibit ecological functions and processes. Those natural processes provide vital benefits and services to humans. The ‘services’ range from food and water provision, to aesthetics, cultural benefits, health and recreation opportunities, and also climate regulation (including water and air quality regulation and flood regulation). These services are referred to collectively as ecosystem services (ES). To understand the impacts of urban pollution, and the opportunities for mitigating its effects, it is important to explore the relationship between pollution and ES. This can lead to better decision-making for urban infrastructure and spaces and can provide increased opportunities for gaining multiple ES from urban environments

    An Inpatient Rehabilitation Interprofessional Care Pathway for Traumatic Hip Fracture: A Pilot Quality Improvement Project

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    Background: Each year over 300,000 older adults are hospitalized for hip fracture. The impact of the cost of hip fracture on the US health care system is estimated to be as high as 9billion,withthetypicalcostofahipfractureepisodearound9 billion, with the typical cost of a hip fracture episode around 30,000. Formalized pathways have been developed and successfully utilized for many patient presentations, including hip fracture, in the acute setting. Although this research is important to the comprehensive care of the elderly hip fracture patient, very little research exists that outlines evidence-based best-practice for patients in the post-acute recovery period. Purpose: The primary aim of this project was to develop an evidence-based, comprehensive, coordinated, and interprofessional care pathway for hip fracture patients in the acute rehabilitation setting to improve the percentage of patients discharging to community settings by 20% from current baseline by the end of the pilot period. Methods: The design of this project was an observational cohort study. Descriptive statistics will be used to compare intervention groups to controls, including frequencies and distributions. Results: The hip fracture tool itself had inconclusive results, the impacts of the effects on team work and enhanced coordination of the care team was realized through reducing institutionalized days for hip fracture patients in acute rehabilitation

    Training a Feed-forward Neural Network with Artificial Bee Colony Based Backpropagation Method

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    Back-propagation algorithm is one of the most widely used and popular techniques to optimize the feed forward neural network training. Nature inspired meta-heuristic algorithms also provide derivative-free solution to optimize complex problem. Artificial bee colony algorithm is a nature inspired meta-heuristic algorithm, mimicking the foraging or food source searching behaviour of bees in a bee colony and this algorithm is implemented in several applications for an improved optimized outcome. The proposed method in this paper includes an improved artificial bee colony algorithm based back-propagation neural network training method for fast and improved convergence rate of the hybrid neural network learning method. The result is analysed with the genetic algorithm based back-propagation method, and it is another hybridized procedure of its kind. Analysis is performed over standard data sets, reflecting the light of efficiency of proposed method in terms of convergence speed and rate.Comment: 14 Pages, 11 figure

    Urban and extra-urban hybrid vehicles: a technological review

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    Pollution derived from transportation systems is a worldwide, timelier issue than ever. The abatement actions of harmful substances in the air are on the agenda and they are necessary today to safeguard our welfare and that of the planet. Environmental pollution in large cities is approximately 20% due to the transportation system. In addition, private traffic contributes greatly to city pollution. Further, “vehicle operating life” is most often exceeded and vehicle emissions do not comply with European antipollution standards. It becomes mandatory to find a solution that respects the environment and, realize an appropriate transportation service to the customers. New technologies related to hybrid –electric engines are making great strides in reducing emissions, and the funds allocated by public authorities should be addressed. In addition, the use (implementation) of new technologies is also convenient from an economic point of view. In fact, by implementing the use of hybrid vehicles, fuel consumption can be reduced. The different hybrid configurations presented refer to such a series architecture, developed by the researchers and Research and Development groups. Regarding energy flows, different strategy logic or vehicle management units have been illustrated. Various configurations and vehicles were studied by simulating different driving cycles, both European approval and homologation and customer ones (typically municipal and university). The simulations have provided guidance on the optimal proposed configuration and information on the component to be used

    HPN Summer 2011 Download Full PDF

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