Donald R. Johnson

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In variational data assimilation, optimal ingestion of the observational data and optimal use of prior physical and statistical information involve the choice of numerous weighting, smoothing and tuning parameters which control the ltering and merging of divers sources of information. Generally these weights must be obtained from a partial and imperfect(More)
In Wahba et al. it was shown how the randomized trace method could be used to adaptively tune numerical weather prediction models via generalized cross validation (GCV) and related methods. In this paper a ''toy'' four-dimensional data assimilation model is developed (actually one space and one time variable), consisting of an equivalent barotropic(More)
A new method, smoothing spline ANOVA, for combining station records of surface air temperature to get the estimates of regional averages as well as gridpoint values is proposed. This method is closely related to the optimal interpolation (also optimal averaging) method. It may be viewed as a generalization of these methods from spatial interpolation methods(More)
OBJECT This study was conducted to compare the quality of life (QOL) in patients with neurogenic intermittent claudication (NIC) secondary to lumbar spinal stenosis (LSS). Using the 36-Item Short Form (SF-36) questionnaire, the authors compared the results obtained in patients treated with the X STOP Interspinous Process Decompression (IPD) System with(More)
Dedicated to the memory of Henry Fleming and his contributions to Meteorology and Mathematics. Abstract We consider the problem of ingesting scattered, noisy, heterogeneous data into an imperfect, evolving mathematical model for the purpose of prediction of a dynamical system. In particular we consider models which perform a three or four dimensional data(More)
The Trade Act of 1988 created the National Institute of Standards and Technology (NIST) from the National Bureau of Standards (NBS). In addition to explicitly defining and reconfirming the traditional measurement services, the law assigned new responsibilities to NIST to assist U.S. industry in capitalizing on new technologies developed in the U.S.(More)
This paper describes the beginning and evolution of microwave rotational spectroscopic research starting in 1954 at the National Bureau of Standards (NBS), located at that time in Washington, DC, through the present at NIST in Gaithersburg, MD. David Lide was hired in 1954 to start this research employing Stark modulated waveguide septum cells. When Donald(More)
Vertical atmospheric cross sections of upward, downward, and net infrared irradiance, infrared cooling, temperature , potential temperature, and water vapor through a jet stream have been constructed for Jan. 7 and 9, 1961, along a line from International Falls, Minn., t o Willemstad, Curacao. The profiles of irradiance and infrared cooling determined from(More)
Objective • Investigate new technologies for cost-effective machining of titanium (Ti) alloys. • Gain in-depth knowledge of the effects of process parameters using three-dimensional (3D) finite element mod-eling (FEM). • Study machining using a production tool with complicated geometry. • Investigate tool wear mechanisms and investigate new tool materials(More)