30 research outputs found

    Regional Pole Placement Design Based Stabilization for Cart Inverted Pendulum System

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    The inverted pendulum has been considered as a benchmark control problem due to its nonlinearity and stabilization around the unstable equilibrium point. To achieve stabilization, it is well known that all the closed loop system poles should lie in left half of s-plane. In present work, different approaches have taken to shift the system poles to left half of the plane. At first Linear Quadratic Regulator (LQR) is used, where the desired pole locations can be achieved by suitably selecting weight matrix of cost function. With this guaranteed cost control scheme, one does not have to bother about specifying closed-loop poles. Next, a two loop PID is designed based on pole matching conditions. Where the closed loop with unknown controller coefficient characteristic equation is compared with desired characteristics, to find out the controller gains. In both the methods, one has to deal with point wise pole placing, which can be tricky sometimes. With the recent development of LMIs tool, regional pole placement is well suited to achieve the goal. At last, a regional pole placement controller is synthesized, where desired specifications are transformed into LMI regions. In present case, a conical sector of left half plane is taken so that stabilisation with better transient performance can be achieve

    Does stroke location predict walk speed response to gait rehabilitation?

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    Objectives Recovery of independent ambulation after stroke is a major goal. However, which rehabilitation regimen best benefits each individual is unknown and decisions are currently made on a subjective basis. Predictors of response to specific therapies would guide the type of therapy most appropriate for each patient. Although lesion topography is a strong predictor of upper limb response, walking involves more distributed functions. Earlier studies that assessed the cortico-spinal tract (CST) were negative, suggesting other structures may be important. Experimental Design: The relationship between lesion topography and response of walking speed to standard rehabilitation was assessed in 50 adult-onset patients using both volumetric measurement of CST lesion load and voxel-based lesion–symptom mapping (VLSM) to assess non-CST structures. Two functional mobility scales, the functional ambulation category (FAC) and the modified rivermead mobility index (MRMI) were also administered. Performance measures were obtained both at entry into the study (3–42 days post-stroke) and at the end of a 6-week course of therapy. Baseline score, age, time since stroke onset and white matter hyperintensities score were included as nuisance covariates in regression models. Principal Observations: CST damage independently predicted response to therapy for FAC and MRMI, but not for walk speed. However, using VLSM the latter was predicted by damage to the putamen, insula, external capsule and neighbouring white matter. Conclusions Walk speed response to rehabilitation was affected by damage involving the putamen and neighbouring structures but not the CST, while the latter had modest but significant impact on everyday functions of general mobility and gait

    A Randomized Controlled Evaluation of the Efficacy of an Ankle-Foot Cast on Walking Recovery Early After Stroke: SWIFT Cast Trial

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    Background. Timely provision of an ankle-foot orthosis (AFO) orthotist customized for individuals early after stroke can be problematic. Objective. To evaluate the efficacy of a therapist-made AFO (SWIFT Cast) for walking recovery. Methods.This was a randomized controlled, observer-blind trial. Participants (n = 105) were recruited 3 to 42 days poststroke.All received conventional physical therapy (CPT) that included use of “off-the-shelf” and orthotist-made AFOs. People allocated to the experimental group also received a SWIFT Cast for up to 6 weeks. Measures were undertaken before randomization, 6 weeks thereafter (outcome), and at 6 months after stroke (follow-up). The primary measure was walking speed. Clinical efficacy evaluation used analysis of covariance. Results. Use of a SWIFT Cast during CPT sessions wassignificantly higher (P < .001) for the SWIFT Cast (55%) than the CPT group (3%). The CPT group used an AFO in 26% of CPT sessions, compared with 11% for the SWIFT Cast group (P = .005). At outcome, walking speed was 0.42 (standard deviation [SD] = 0.37) m/s for the CPT group and 0.32 (SD = 0.34) m/s for the SWIFT Cast group. Follow-up walking speed was 0.53 (SD = 0.38) m/s for the CPT group and 0.43 (0.34) m/s for the SWIFT Cast group. Differences, after accounting for minimization factors, were insignificant at outcome (P = .345) and follow-up (P = .360). Conclusion and implications.SWIFT Cast did not enhance the benefit of CPT, but the control group had greater use of another AFO. However, SWIFT Cast remains a clinical option because it is low cost and custom-made by therapists who can readily adapt it during the rehabilitation period

    Current and Future Disease Burden From Ambient Ozone Exposure in India

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    Long‐term ambient ozone (O₃) exposure is a risk factor for human health. We estimate the source‐specific disease burden associated with long‐term O₃ exposure in India at high spatial resolution using updated risk functions from the American Cancer Society Cancer Prevention Study II. We estimate 374,000 (95UI: 140,000–554,000) annual premature mortalities using the updated risk function in India in 2015, 200% larger than estimates using the earlier American Cancer Society Cancer Prevention Study II risk function. We find that land transport emissions dominate the source contribution to this disease burden (35%), followed by emissions from power generation (23%). With no change in emissions by 2050, we estimate 1,126,000 (95UI: 421,000–1,667,000) annual premature mortalities, an increase of 200% relative to 2015 due to population aging and growth increasing the number of people susceptible to air pollution. We find that the International Energy Agency New Policy Scenario provides small changes (+1%) to this increasing disease burden from the demographic transition. Under the International Energy Agency Clean Air Scenario we estimate 791,000 (95UI: 202,000–1,336,000) annual premature mortalities in 2050, avoiding 335,000 annual premature mortalities (45% of the increase) compared to the scenario of no emission change. Our study highlights that critical public health benefits are possible with stringent emission reductions, despite population growth and aging increasing the attributable disease burden from O₃ exposure even under such strong emission reductions. The disease burden attributable to ambient fine particulate matter exposure dominates that from ambient O₃ exposure in the present day, while in the future, they may be similar in magnitude

    Air quality in Delhi during the Commonwealth Games

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    Air quality during the Commonwealth Games (CWG, held in Delhi in October 2010) is analyzed using a new air quality forecasting system established for the games. The CWG stimulated enhanced efforts to monitor and model air quality in the region. The air quality of Delhi during the CWG had high levels of particles with mean values of PM2.5 and PM10 at the venues of 111 and 238 μg m−3, respectively. Black carbon (BC) accounted for ~ 10% of the PM2.5 mass. It is shown that BC, PM2.5 and PM10 concentrations are well predicted, but with positive biases of ~ 25%. The diurnal variations are also well captured, with both the observations and the modeled values showing nighttime maxima and daytime minima. A new emissions inventory, developed as part of this air quality forecasting initiative, is evaluated by comparing the observed and predicted species-species correlations (i.e., BC : CO; BC : PM2.5; PM2.5 : PM10). Assuming that the observations at these sites are representative and that all the model errors are associated with the emissions, then the modeled concentrations and slopes can be made consistent by scaling the emissions by 0.6 for NOx, 2 for CO, and 0.7 for BC, PM2.5, and PM10. The emission estimates for particles are remarkably good considering the uncertainty in the estimates due to the diverse spread of activities and technologies that take place in Delhi and the rapid rates of change

    Extraction and estimation of antistatic agent glycerol monostearate in polypropylene by gas chromatography coupled with flame ionisation detector

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    153-157A new method has been developed for the estimation of an antistatic agent glycerol monostearate (GMS) in polypropylene (PP) over gas chromatography coupled with flame ionization detector (GC-FID). In the present work, selection of suitable sample specimen, sample weight, solvent mixture, extraction time, and temperature have been identified for the extraction of GMS in the PP resin. In-house polypropylene pellet has been used for study and the GMS extorted into n-hexane-ethyl acetate and quantified using GC-FID over 100% Dimethyl polysiloxane column. The method limit of detection is 1 mg/L and the limit of quantification is 5-750 mg/kg in PP resin with a correlation coefficient greater than 0.999. This method is accurate and has not found any interference with other co additives used in the propylene
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