5,760 research outputs found

    Integrated Navigation System: Not a Sum of Its Parts

    Get PDF
    Similar to the evolutionary process for living organisms, marine navigation systems are becoming increasingly complex and sophisticated. Both by design and function, shipboard and shore-based navigation systems are no longer individual equipment components operating independently. Instead, the trend is toward integration, data fusion and synergy. One example of this are new Performance Standards being considered by IMO to achieve a “harmonized” presentation of all navigation-related information on the display of an integrated navigation system (INS). Unlike a dedicated display for ECDIS or radar, the new INS displays will be a task-oriented composite presentations that enable the mariner to configure the display for an operational situation by selecting specific chart, radar, radar plotting aids (ARPA) and AIS information that is required for the task-at-hand. This paper gives a brief overview of the trend toward the development of INS. In addition to a brief summary of IMO performance standards for navigation equipment/systems, specific mention is made about a BSH (Germany) report on the “Functional Scope and Model of INS.” A discussion is provided about the challenges of providing navigation safety information that goes beyond traditional boundaries of products and services. Currently, many agencies continue to produce individual products and services on a component basis. Hydrographic offices grapple with trying to provide multiple products and services for paper charts, raster navigational charts (RNCs) and electronic navigational charts (ENCs) while a same time, Coast Guard and Maritime Safety agencies focus on improving Aids-to-Navigation (AtoN), Vessel Traffic Services (VTS), AIS networks -- and more recently, port security. In some respects, the continued concentration on separate products and services represents an organizational reluctance to change. This in turn, results in a fragmented, sub-optimal approach to the safety-of-navigation caused by the inability to provide mariners with “seamless” information at reasonable cost. In particular, hydrographic offices must be willing to recognize that chart information can no longer be considered to be separate, individual products. When it comes to the provision and use of chart-related information for use in an INS, the focus needs to shift to what information is actually desired, how it will be provided, what other information it will be used with, and whether it is truly up-todate

    The Nonreligious – Nonspiritual Scale (NRNSS): Measuring Everything from Atheists to Zionists

    Get PDF
    Although hundreds of measures of personal religiousness and spirituality exist, none are capable of reliably and validly assessing individuals who identify as nonreligious and nonspiritual. There is a need to develop a valid and reliable measure of (non)religiousness and (non)spirituality. This article discusses these problems, and presents the development and initial validation of a 17-item Nonreligious-Nonspiritual Scale (NRNSS) across three studies. The NRNSS exhibited high internal consistency (α \u3e .94) and high test-retest reliability (r = .92). Two exploratory and one confirmatory factor analysis of the NRNSS supported the hypothesized two-factor solution: (a) institutional religiousness and (b) individualistic spirituality. The NRNSS also demonstrated convergent validity through theoretically-expected correlations with established measures of religiousness and spirituality (the Cross-Cultural Dimensions of Religiosity, Humanistic Morality, and Traditional Religious Morality scales). In summary, the NRNSS may work as an initial attempt to address the limitations of other scales for capturing how religious/nonreligious/nonspiritual individuals are

    On the Receiving End: Discrimination Toward the Non-Religious in the United States [post-print]

    Get PDF
    The present study examines perceived discrimination faced by religious ‘nones’. After distinguishing between atheists, agnostics, and ‘nones’ who are deists or theists, we use nationally representative data from the 2008 American Religious Identification Survey (ARIS) to study the contexts in which these various types of religious ‘nones’ have reported experiencing discrimination. The strongest predictor of such discrimination was not theological atheism or agnosticism but self-identifying as an atheist or agnostic when asked what one\u27s religion is. Context-specific predictors of discrimination are age, region of the country, rural versus urban location, parents’ religious identifications, educational attainment, ethnicity and race. Results are consistent with the view that people who hold more pronounced views are more likely to report discrimination

    Chronic Elbow Dislocation Treated with Open Reduction and Lateral Ulnar Collateral Ligament Reconstruction

    Get PDF
    In the United States, chronic unreduced elbow dislocations are rare injuries. We report the successful short-term outcome of a chronic elbow dislocation treated with open reduction and lateral ulnar collateral ligament reconstruction using a split semitendinosus allograft in a figure-of-8 technique without use of hinged external fixation. The authors have obtained the patient’s written informed consent for print and electronic publication of the case report

    Type and Timing of Rehabilitation Following Acute and Subacute Spinal Cord Injury: A Systematic Review

    Get PDF
    Objectives: The objective of this study was to conduct a systematic review of the literature to address the following clinical questions: In adult patients with acute and subacute complete or incomplete traumatic SCI, (1) does the time interval between injury and commencing rehabilitation affect outcome?; (2) what is the comparative effectiveness of different rehabilitation strategies, including different intensities and durations of treatment?; (3) are there patient or injury characteristics that affect the efficacy of rehabilitation?; and (4) what is the cost-effectiveness of various rehabilitation strategies? Methods: A systematic search was conducted for literature published through March 31, 2015 that evaluated rehabilitation strategies in adults with acute or subacute traumatic SCI at any level. Studies were critically appraised individually and the overall strength of evidence was evaluated using methods proposed by the GRADE (Grades of Recommendation Assessment, Development and Evaluation) working group. Results: The search strategy yielded 384 articles, 19 of which met our inclusion criteria. Based on our results, there was no difference between body weight–supported treadmill training and conventional rehabilitation with respect to improvements in Functional Independence Measure (FIM) Locomotor score, Lower Extremity Motor Scores, the distance walked in 6 minutes or gait velocity over 15.2 m. Functional electrical therapy resulted in slightly better FIM Motor, FIM Self-Care, and Spinal Cord Independence Measure Self-Care subscores compared with conventional occupational therapy. Comparisons using the Toronto Rehabilitation Institute Hand Function Test demonstrated no differences between groups in 7 of 9 domains. There were no clinically important differences in Maximal Lean Test, Maximal Sidewards Reach Test, T-shirt Test, or the Canadian Occupational Performance Measure between unsupported sitting training and standard in-patient rehabilitation. Conclusion: The current evidence base for rehabilitation following acute and subacute spinal cord injury is limited. Methodological challenges have contributed to this and further research is still needed. © 2017, © The Author(s) 2017

    Flight Test of the F/A-18 Active Aeroelastic Wing Airplane

    Get PDF
    Successful flight-testing of the Active Aeroelastic Wing airplane was completed in March 2005. This program, which started in 1996, was a joint activity sponsored by NASA, Air Force Research Laboratory, and industry contractors. The test program contained two flight test phases conducted in early 2003 and early 2005. During the first phase of flight test, aerodynamic models and load models of the wing control surfaces and wing structure were developed. Design teams built new research control laws for the Active Aeroelastic Wing airplane using these flight-validated models; and throughout the final phase of flight test, these new control laws were demonstrated. The control laws were designed to optimize strategies for moving the wing control surfaces to maximize roll rates in the transonic and supersonic flight regimes. Control surface hinge moments and wing loads were constrained to remain within hydraulic and load limits. This paper describes briefly the flight control system architecture as well as the design approach used by Active Aeroelastic Wing project engineers to develop flight control system gains. Additionally, this paper presents flight test techniques and comparison between flight test results and predictions

    Development and Testing of Control Laws for the Active Aeroelastic Wing Program

    Get PDF
    The Active Aeroelastic Wing research program was a joint program between the U.S. Air Force Research Laboratory and NASA established to investigate the characteristics of an aeroelastic wing and the technique of using wing twist for roll control. The flight test program employed the use of an F/A-18 aircraft modified by reducing the wing torsional stiffness and adding a custom research flight control system. The research flight control system was optimized to maximize roll rate using only wing surfaces to twist the wing while simultaneously maintaining design load limits, stability margins, and handling qualities. NASA Dryden Flight Research Center developed control laws using the software design tool called CONDUIT, which employs a multi-objective function optimization to tune selected control system design parameters. Modifications were made to the Active Aeroelastic Wing implementation in this new software design tool to incorporate the NASA Dryden Flight Research Center nonlinear F/A-18 simulation for time history analysis. This paper describes the design process, including how the control law requirements were incorporated into constraints for the optimization of this specific software design tool. Predicted performance is also compared to results from flight
    • 

    corecore