Evaluating the effect of accuracy ratios on the percent of calibrations which are out of tolerance

The standard practice in calibration laboratories across the country, including the Measurement Standards and Calibration Laboratory (MSCL) at the Johnson Space Center, is to use accuracy ratios to determine if instruments are in-tolerance rather than computing the actual uncertainty associated with the instruments. In the past, the accepted practice was to use an accuracy ratio of 10:1, but then state of the art advanced to the point where the 10:1 ratio could no longer be maintained, and the ratio was arbitrarily lowered to 4:1. It is now becoming increasingly difficult to maintain the 4:1 accuracy ratio, and in some cases 1:1 is the best that can be achieved. However, the effect of using these small accuracy ratios on the number of mistakes made in classifying instruments as in or out of tolerance is completely unknown. In order to assess the effect of using accuracy ratios in calibration, a simulation program was written to compute the proportion of instruments determined to be out of tolerance which were actually in, denoted by alpha, and the proportion of instruments determined to be in-tolerance which were actually out, denoted by beta. This was done for accuracy ratios of 1:1 and 10:1, for one to five progressive calibrations, under varying standard and instrument conditions. Selected results are presented and explained

Relating multitemporal meteorological satellite data to climatological data for Africa

The questions of surface-atmosphere interaction and effects of land surface changes have been investigated by studying the energy balance over Africa. The energy and mass balance model being developed is an adaptation of the Lettau climatonomy model. The climatonic approach is a systems approach which encompasses: (1) a process, (2) an input to the process (forcing function), (3) an output from the process (response function), (4) feedback, and (5) control or management of the system. Steady-state climate is described and parametrized using a series of one-dimensional differential continuity and balance equations for energy and mass

Estimating equilibrium real interest rates in real-time

We use a range of simple models and 22 years of real-time data vintages for the U.S. to assess the difficulties of estimating the equilibrium real interest rate in real time. Model specifications differ according to whether the time-varying equilibrium real rate is linked to trend growth, and whether potential output and growth are defined by the CBO?s estimates or treated as unobserved variables. Our results reveal a high degree of specification uncertainty, an important one-sided filtering problem, and considerable imprecision due to data uncertainty. Also, the link between trend growth and the equilibrium real rate is shown to be quite weak. Overall, we conclude that statistical estimates of the equilibrium real rate will be difficult to use reliably in practical policy applications. --real-time-data,time-varying parameter,Kalman filter,trend growth

Review Of Marche Des Arts Du Spectacle Africain (Masa \u2797)

A panoply of over fifty dance, music, and theatre events from twenty African countries was performed at seven different venues, including indoor and outdoor theatres, clubs, concert halls, courtyards, gardens, and a sports stadium. The Moroccan company Ballet-Théâtre Zinoun presented Psyché Ou La Légende D\u27Adonis, a revisiting of the Adonis legend in which the balletic movement vocabulary and neoclassical choreographic techniques were interspersed with scenes in which a narrator alternated the words of Arab poets with riffs on his soprano saxophone

The demand for M2, opportunity cost, and financial change

An analysis of the recent weakness in M2 growth that attempts to measure the opportunity cost of the aggregate more accurately and that explores the potential effects of the thrift industry restructuring on the adjustment of money demand to its long-run equilibrium level.Money supply ; Savings and loan associations

Static Footprint Local Forces, Areas, and Aspect Ratios for Three Type 7 Aircraft Tires

The National Tire Modeling Program (NTMP) is a joint NASA/industry effort to improve the understanding of tire mechanics and develop accurate analytical design tools. This effort includes fundamental analytical and experimental research on the structural mechanics of tires. Footprint local forces, areas, and aspect ratios were measured. Local footprint forces in the vertical, lateral, and drag directions were measured with a special footprint force transducer. Measurements of the local forces in the footprint were obtained by positioning the transducer at specified locations within the footprint and externally loading the tires. Three tires were tested: (1) one representative of those used on the main landing gear of B-737 and DC-9 commercial transport airplanes, (2) a nose landing gear tire for the Space Shuttle Orbiter, and (3) a main landing gear tire for the Space Shuttle Orbiter. Data obtained for various inflation pressures and vertical loads are presented for two aircraft tires. The results are presented in graphical and tabulated forms