1,250 research outputs found

    Poincar\'e Gauge Theory With Coupled Even And Odd Parity Dynamic Spin-0 Modes: Dynamic Equations For Isotropic Bianchi Cosmologies

    Full text link
    We are investigating the dynamics of a new Poincar\'e gauge theory of gravity model, which has cross coupling between the spin-0+^+ and spin-0−^- modes. To this end we here consider a very appropriate situation---homogeneous-isotropic cosmologies---which is relatively simple, and yet all the modes have non-trivial dynamics which reveals physically interesting and possibly observable results. More specifically we consider manifestly isotropic Bianchi class A cosmologies; for this case we find an effective Lagrangian and Hamiltonian for the dynamical system. The Lagrange equations for these models lead to a set of first order equations that are compatible with those found for the FLRW models and provide a foundation for further investigations. Typical numerical evolution of these equations shows the expected effects of the cross parity coupling.Comment: 13 pages, 2 figure

    CALIBRATION OF PRESSURE SENSORS FOR HAND GRIP MEASUREMENT

    Get PDF
    The purpose of this study was to assess the accuracy of grip force sensors. Methods: Several standard weights were used to calibrate the grip sensor in the static condition, The descriptive statistics and linear regression were used to present the accuracy and errors. Results: Results of this study showed a high level of sensing areas linear relationship under static loading. Conclusion: Data from this study showed high accuracy of the pressure sensor. The pressure sensor could te used for hand grip measurement

    Improving the Motion Performance for an Intelligent Walking Support Machine by RLS Algorithm

    Get PDF
    To make the old people and handicapped people move easily by themselves, an omni-directional walking support machine (WSM) has been developed. In our previous study, to improve the motion performance of the WSM, a digital acceleration control method has been developed to deal with the nonlinear friction. However, the design of the digital acceleration controller requires to know the exact plant parameters of the WSM which are variable due to center of gravity (COG) shift and load changes. The change of the plant parameters affects the motion performance of the digital acceleration control system. Therefore, in this paper, a discrete-time system identification method using recursive least squares (RLS) algorithm is proposed to online identify the WSM’s plant parameters for the digital acceleration controller. Simulations are executed and compared with the digital acceleration controller without using RLS algorithm, and the results demonstrate the feasibility and effectiveness of the proposed control method

    Baseline morning cortisol level as a predictor of pituitary-adrenal reserve: a comparison across three assays

    Get PDF
    The short ACTH stimulation test (250 μg) is the dynamic test most frequently used to assess adrenal function. It is possible that a single basal cortisol could be used to predict the dynamic response, but research has been hampered by the use of different assays and thresholds. OBJECTIVE: To propose a morning baseline cortisol criterion of three of the most commonly used modern cortisol immunoassays - Advia Centaur (Siemens), Architect (Abbott) and the Roche Modular System (Roche) - that could predict adrenal sufficiency. DESIGN: Observational, retrospective cross-sectional study at two centres. PATIENTS AND MEASUREMENTS: Retrospective analysis of the results of 1019 Short Synacthen tests (SSTs) with the Advia Centaur, 449 SSTs with the Architect and 2050 SSTs with the Roche Modular System assay. Serum cortisol levels were measured prior to injection of 250 μg Synacthen and after 30 min. Overall, we were able to collate data from a total of 3518 SSTs in 3571 patients. RESULTS: Using receiver-operator curve analysis, baseline cortisol levels for predicting passing the SST with 100% specificity were 358 nmol/l for Siemens, 336 nmol/l for Abbott and 506 nmol/l for Roche. Utilizing these criteria, 589, 158 and 578 SSTs, respectively, for Siemens, Abbott and Roche immunoassays could have been avoided. CONCLUSIONS: We have defined assay-specific morning cortisol levels that are able to predict the integrity of the hypothalamo-pituitary-adrenal axis. We propose that this represents a valid tool for the initial assessment of adrenal function and has the potential to obviate the need for dynamic testing in a significant number of patients
    • …
    corecore