113 research outputs found

    Challenges in Achieving Trajectory-Based Operations

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    In the past few years much of the global ATM research community has proposed advanced systems based on Trajectory-Based Operations (TBO). The concept of TBO uses four-dimensional aircraft trajectories as the base information for managing safety and capacity. Both the US and European advanced ATM programs call for the sharing of trajectory data across different decision support tools for successful operations. However, the actual integration of TBO systems presents many challenges. Trajectory predictors are built to meet the specific needs of a particular system and are not always compatible with others. Two case studies are presented which examine the challenges of introducing a new concept into two legacy systems in regards to their trajectory prediction software. The first case describes the issues with integrating a new decision support tool with a legacy operational system which overlap in domain space. These tools perform similar functions but are driven by different requirements. The difference in the resulting trajectories can lead to conflicting advisories. The second case looks at integrating this same new tool with a legacy system originally developed as an integrated system, but diverged many years ago. Both cases illustrate how the lack of common architecture concepts for the trajectory predictors added cost and complexity to the integration efforts

    Future of Interoperability (IR) Research

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    This presentation provides a forum for discussion about the work presented by the Interoperability (IR) focus area and the future of interoperability research. Of particular interest will be the direction IR research should take in future year

    Center-TRACON Automation System (CTAS) En Route Trajectory Predictor Requirements and Capabilities

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    This requirements framework document is designed to support the capture of requirements and capabilities for state-of-the-art trajectory predictors (TPs). This framework has been developed to assist TP experts in capturing a clear, consistent, and cross-comparable set of requirements and capabilities. The goal is to capture capabilities (types of trajectories that can be built), functional requirements (including inputs and outputs), non-functional requirements (including prediction accuracy and computational performance), approaches for constraint relaxation, and input uncertainties. The sections of this framework are based on the Common Trajectory Predictor structure developed by the FAA/Eurocontrol Cooperative R&D Action Plan 16 Committee on Common Trajectory Prediction. It is assumed that the reader is familiar with the Common TP Structure.1 This initial draft is intended as a first cut capture of the En Route TS Capabilities and Requirements. As such, it contains many annotations indicating possible logic errors in the CTAS code or in the description provided. It is intended to work out the details of the annotations with NASA and to update this document at a later time

    Women’s experiences of gestational breast cancer and their interactions with the health care system: a scoping review

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    Aim: To report the evidence of women's experiences following a diagnosis of gestational breast cancer (GBC) and their interactions with the healthcare system. Design: A systematic scoping review. Data Sources: This scoping review systematically searched Medline, CINAHL, Psych INFO, EMBASE and SCOPUS, in addition to six grey literature databases in October 2021. A 2020 PRISMA flow diagram depicting the flow of information. Review Methods: Guided by six steps in Arksey and OMalley's Framework (2005). One researcher completed the literature review, and four independently screened the titles and abstracts related to the eligibility criteria. Results: Totalling 25 articles, these studies comprise 2 quantitative, 20 qualitative, 1 mixed-method and 2 other documents, a book and debate. Thematic analysis was guided by Braun and Clarke (2006) to identify an overarching theme of adjustment that underpinned women's narratives and was reinforced by four major and several minor themes. The four major themes were: psychological impact, motherhood, treatment and communication. The relationship between the themes contextualizes the enormous complexity concerning women's experiences with GBC. Conclusion: Cancer management for GBC is complex and multifaceted. At a time of conflicting emotions for women, Multidisciplinary teams are well placed to provide support, normalize the woman's experience of motherhood, demonstrate an understanding of treatment effects, and communicate in a considerate and empathetic manner with information that is timely and relevant. GBC management involves doctors, nurses, midwives and many other healthcare professionals, which can add to the impost of diagnosis. Impact: This scoping review contributes to a better understanding of women's experience of GBC. The results may inform improvements in the support and communication for these women with GBC and their families

    Analysis of Air Traffic Track Data with the AutoBayes Synthesis System

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    The Next Generation Air Traffic System (NGATS) is aiming to provide substantial computer support for the air traffic controllers. Algorithms for the accurate prediction of aircraft movements are of central importance for such software systems but trajectory prediction has to work reliably in the presence of unknown parameters and uncertainties. We are using the AutoBayes program synthesis system to generate customized data analysis algorithms that process large sets of aircraft radar track data in order to estimate parameters and uncertainties. In this paper, we present, how the tasks of finding structure in track data, estimation of important parameters in climb trajectories, and the detection of continuous descent approaches can be accomplished with compact task-specific AutoBayes specifications. We present an overview of the AutoBayes architecture and describe, how its schema-based approach generates customized analysis algorithms, documented C/C++ code, and detailed mathematical derivations. Results of experiments with actual air traffic control data are discussed

    Survey and Method for Determination of Trajectory Predictor Requirements

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    A survey of air-traffic-management researchers, representing a broad range of automation applications, was conducted to document trajectory-predictor requirements for future decision-support systems. Results indicated that the researchers were unable to articulate a basic set of trajectory-prediction requirements for their automation concepts. Survey responses showed the need to establish a process to help developers determine the trajectory-predictor-performance requirements for their concepts. Two methods for determining trajectory-predictor requirements are introduced. A fast-time simulation method is discussed that captures the sensitivity of a concept to the performance of its trajectory-prediction capability. A characterization method is proposed to provide quicker, yet less precise results, based on analysis and simulation to characterize the trajectory-prediction errors associated with key modeling options for a specific concept. Concept developers can then identify the relative sizes of errors associated with key modeling options, and qualitatively determine which options lead to significant errors. The characterization method is demonstrated for a case study involving future airport surface traffic management automation. Of the top four sources of error, results indicated that the error associated with accelerations to and from turn speeds was unacceptable, the error associated with the turn path model was acceptable, and the error associated with taxi-speed estimation was of concern and needed a higher fidelity concept simulation to obtain a more precise resul

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    Definition and Demonstration of a Methodology for Validating Aircraft Trajectory Predictors

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    This paper presents a new methodology for validating an aircraft trajectory predictor, inspired by the lessons learned from a number of field trials, flight tests and simulation experiments for the development of trajectory-predictor-based automation. The methodology introduces new techniques and a new multi-staged approach to reduce the effort in identifying and resolving validation failures, avoiding the potentially large costs associated with failures during a single-stage, pass/fail approach. As a case study, the validation effort performed by the Federal Aviation Administration for its En Route Automation Modernization (ERAM) system is analyzed to illustrate the real-world applicability of this methodology. During this validation effort, ERAM initially failed to achieve six of its eight requirements associated with trajectory prediction and conflict probe. The ERAM validation issues have since been addressed, but to illustrate how the methodology could have benefited the FAA effort, additional techniques are presented that could have been used to resolve some of these issues. Using data from the ERAM validation effort, it is demonstrated that these new techniques could have identified trajectory prediction error sources that contributed to several of the unmet ERAM requirements

    Development of an evidence-based regimen of prednisolone to treat giant cell arteritis - the Norwich regimen

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    We have reviewed the literature to form a bespoke regimen for daily oral prednisolone (DP) in GCA. Initial DP in clinical trials is 40-60 mg daily, but relapse rates are 67-92%. Cumulative prednisolone (CP) of 3.2 and 3.9 g (at 6 months) resulted in a relapse rate of 83 and 67%, respectively; and 3 and 3.9 g (at 12 months) resulted in 92 and 82% relapse, respectively. CP was 6.2-7.1 g in the first year. Mean DP was 18.8 mg at 3 months and 6.6-7.4 mg at 12 months. The duration of treatment with prednisolone for GCA was 22-26 months. The CP to achieve discontinuation was 6.5-12.1 g. Using these data, the Norwich regimen starts DP at 1 mg/kg/day of lean body mass, discontinuing over 100 weeks. For the average UK woman, initial DP is 45 mg daily, reaching 21 mg daily by 12 weeks and 6 mg daily by 52 weeks. The CP for the average UK woman would be 6.5 g at 52 weeks and 7.4 g to discontinuation

    The role and scope of contemporary midwifery practice in Australia: A scoping review of the literature

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    Problem: Little is known about the breadth of midwifery scope within Australia, and few midwives work to their full scope of practice. Background: Midwives in Australia are educated and professionally accountable to work in partnership with childbearing women and their families, yet they are currently hindered from practicing within their full scope of practice by contextual influences. Aims: To perform a scoping review of the literature to map out the role and scope of contemporary midwifery practice in Australia To identify any key issues that impact upon working within the full scope of midwifery practice in the Australian context Methods: A scoping review of the literature guided by the Arksey and O’Malley’s five-stage methodological framework, and the ‘best fit’ framework synthesis using the Nursing and Midwifery Board of Australia’s Midwifery Standards for Practice. Findings: Key themes that emerged from the review included Partnership with women; The professional role of the midwife; and Contextual influences upon midwifery practice. Discussion: Tensions were identified between the midwifery scope of practice associated with optimal outcomes for women and babies supported by current evidence and the actual role and scope of most midwives employed in models of care in the current Australian public healthcare system. Conclusions: There is a mismatch between the operational parameters for midwifery practice in Australia and the evidence-based models of continuity of midwifery carer that are associated with optimal outcomes for childbearing women and babies and the midwives themselves
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