6,535 research outputs found

    Spectral Characterization of Suspected Acid Deposition Damage in Red Spruce (picea Rubens) Stands from Vermont

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    In an attempt to demonstrate the utility of remote sensing systems to monitor sites of suspected acid rain deposition damage, intensive field activities, coupled with aircraft overflights, were centered on red spruce stands in Vermont during August and September of 1984. Remote sensing data were acquired using the Airborne Imaging Spectrometer, Thematic Mapper Simulator, Barnes Model 12 to 1000 Modular Multiband Radiometer and Spectron Engineering Spectrometer (the former two flown on the NASA C-130; the latter two on A Bell UH-1B Iroquois Helicopter). Field spectral data were acquired during the week of the August overflights using a high spectral resolution spectrometer and two broad-band radiometers. Preliminary analyses of these data indicate a number of spectral differences in vegetation between high and low damage sites. Some of these differences are subtle, and are observable only with high spectral resolution sensors; others are less subtle and are observable using broad-band sensors

    TCMS operations and maintenance philosophy

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    The purpose is to describe the basic philosophies of operating and maintaining the Test, Control, and Monitor System (TCMS) equipment. TCMS is a complex and sophisticated checkout system. Operations and maintenance processes developed to support it will be based upon current experience, but will be focused on the specific needs of TCMS in support of Space Station Freedom Program (SSFP) and related activities. An overview of the operations and maintenance goals and philosophies are presented. The assumptions, roles and responsibilities, concepts and interfaces for operation, on-line maintenance, off-line support, and Operations and Maintenance (O&M) personnel training on all TCMS equipment located at KSC are described

    Sensor failure detection system

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    Advanced concepts for detecting, isolating, and accommodating sensor failures were studied to determine their applicability to the gas turbine control problem. Five concepts were formulated based upon such techniques as Kalman filters and a screening process led to the selection of one advanced concept for further evaluation. The selected advanced concept uses a Kalman filter to generate residuals, a weighted sum square residuals technique to detect soft failures, likelihood ratio testing of a bank of Kalman filters for isolation, and reconfiguring of the normal mode Kalman filter by eliminating the failed input to accommodate the failure. The advanced concept was compared to a baseline parameter synthesis technique. The advanced concept was shown to be a viable concept for detecting, isolating, and accommodating sensor failures for the gas turbine applications

    Sensor failure detection for jet engines

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    Revisions to the advanced sensor failure detection, isolation, and accommodation (DIA) algorithm, developed under the sensor failure detection system program were studied to eliminate the steady state errors due to estimation filter biases. Three algorithm revisions were formulated and one revision for detailed evaluation was chosen. The selected version modifies the DIA algorithm to feedback the actual sensor outputs to the integral portion of the control for the nofailure case. In case of a failure, the estimates of the failed sensor output is fed back to the integral portion. The estimator outputs are fed back to the linear regulator portion of the control all the time. The revised algorithm is evaluated and compared to the baseline algorithm developed previously

    Insights from quantitative and mathematical modelling on the proposed 2030 goal for gambiense human African trypanosomiasis (gHAT)

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    Gambiense human African trypanosomiasis (gHAT) is a parasitic, vector-borne neglected tropical disease that has historically affected populations across West and Central Africa and can result in death if untreated. Following from the success of recent intervention programmes against gHAT, the World Health Organization (WHO) has defined a 2030 goal of global elimination of transmission (EOT). The key proposed indicator to measure achievement of the goal is to have zero reported cases. Results of previous mathematical modelling and quantitative analyses are brought together to explore both the implications of the proposed indicator and the feasibility of achieving the WHO goal. Whilst the indicator of zero case reporting is clear and measurable, it is an imperfect proxy for EOT and could arise either before or after EOT is achieved. Lagging reporting of infection and imperfect diagnostic specificity could result in case reporting after EOT, whereas the converse could be true due to underreporting, lack of coverage, and cryptic human and animal reservoirs. At the village-scale, the WHO recommendation of continuing active screening until there are three years of zero cases yields a high probability of local EOT, but extrapolating this result to larger spatial scales is complex. Predictive modelling of gHAT has consistently found that EOT by 2030 is unlikely across key endemic regions if current medical-only strategies are not bolstered by improved coverage, reduced time to detection and/or complementary vector control. Unfortunately, projected costs for strategies expected to meet EOT are high in the short term and strategies that are cost-effective in reducing burden are unlikely to result in EOT by 2030. Future modelling work should aim to provide predictions while taking into account uncertainties in stochastic dynamics and infection reservoirs, as well as assessment of multiple spatial scales, reactive strategies, and measurable proxies of EOT

    HYTESS: A hypothetical turbofan engine simplified simulation

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    A users manual for a hypothetical turbofan engine simplified simulation is presented. This digital simulation exists as FORTRAN source code. The program is self-contained and was developed to offer those interested in engine dynamics and controls research an efficient, realistic, and easily used engine simulation. The engine is modeled using a state space formulation. Matrix elements within the linear state space structure are nonlinear functions of various engine variables

    Coping with pain in the hip or knee in relation to physical disability in community-living elderly people

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    __Objective__ To investigate the use of pain coping strategies by community-living older people with pain in the hip or knee and the mediating role of coping with pain in the relationship between the chronicity of pain and physical disability. __Methods__ A group of 157 people with pain 'in the last month' was identified. Coping with pain was assessed with the Pain Coping Inventory, physical disability with the Sickness Impact Profile, and household and sport activities with a validated structured interview method. __Results__ People with chronic pain used relatively more 'resting,' and 'reducing demands' as pain coping strategies. Pain chronicity made a significant contribution to physical disability; however, when corrected for other variables in a regression model, no significant partial correlation was found. __Conclusion__ We conclude that pain coping has a mediating role in the relationship between pain chronicity and physical disability. Less use of 'resting' and a physically active lifestyle are independently associated with less physical disability

    Weight loss, glycemic control, and cardiovascular disease risk factors in response to differential diet composition in a weight loss program in type 2 diabetes: a randomized controlled trial.

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    ObjectiveTo test whether a weight loss program promotes greater weight loss, glycemic control, and improved cardiovascular disease risk factors compared with control conditions and whether there is a differential response to higher versus lower carbohydrate intake.Research design and methodsThis randomized controlled trial at two university medical centers enrolled 227 overweight or obese adults with type 2 diabetes and assigned them to parallel in-person diet and exercise counseling, with prepackaged foods in a planned menu during the initial phase, or to usual care (UC; two weight loss counseling sessions and monthly contacts).ResultsRelative weight loss was 7.4% (95% CI 5.7-9.2%), 9.0% (7.1-10.9%), and 2.5% (1.3-3.8%) for the lower fat, lower carbohydrate, and UC groups (P < 0.001 intervention effect). Glycemic control markers and triglyceride levels were lower in the intervention groups compared with UC group at 1 year (fasting glucose 141 [95% CI 133-149] vs. 159 [144-174] mg/dL, P = 0.023; hemoglobin A1c 6.9% [6.6-7.1%] vs. 7.5% [7.1-7.9%] or 52 [49-54] vs. 58 [54-63] mmol/mol, P = 0.001; triglycerides 148 [134-163] vs. 204 [173-234] mg/dL, P < 0.001). The lower versus higher carbohydrate groups maintained lower hemoglobin A1c (6.6% [95% CI 6.3-6.8%] vs. 7.2% [6.8-7.5%] or 49 [45-51] vs. 55 [51-58] mmol/mol) at 1 year (P = 0.008).ConclusionsThe weight loss program resulted in greater weight loss and improved glycemic control in type 2 diabetes

    Електронний путівник і координатор (Завдання та функції інформаційного ресурсу Науково-видавничої ради НАН України «Наукові публікації і видавнича діяльність»)

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    Purpose: Physical activity (PA) is an important behavior when it comes to preventing or slowing down disablement caused by aging and chronic diseases. It remains unclear whether PA can directly prevent or reduce disability in activities of daily living (ADL). This article presents a meta-analysis of the association between PA and the incidence and progression of basic ADL disability (BADL). Methods: Electronic literature search and cross-referencing of prospective longitudinal studies of PA and BADL in community dwelling older adults (50+) with baseline and follow-up measurements, multivariate analysis and reporting a point estimate for the association. Results: Compared with a low PA, a medium/high PA level reduced the risk of incident BADL disability by 0.51 (95% CI: 0.38, 0.68; p < 001), based on nine longitudinal studies involving 17,000 participants followed up for 3–10 years. This result was independent of age, length of follow-up, study quality, and differences in demographics, health status, functional limitations, and lifestyle. The risk of progression of BADL disability in older adults with a medium/high PA level compared with those with a low PA level was 0.55 (95% CI: 0.42, 0.71; p < 001), based on four studies involving 8500 participants. Discussion: This is the first meta-analysis to show that being physically active prevents and slows down he disablement process in aging or diseased populations, positioning PA as the most effective preventive trategy in preventing and reducing disability, independence and health care cost in aging societies
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