Subsonic flight test evaluation of a propulsion system parameter estimation process for the F100 engine

Integrated engine-airframe optimal control technology may significantly improve aircraft performance. This technology requires a reliable and accurate parameter estimator to predict unmeasured variables. To develop this technology base, NASA Dryden Flight Research Facility (Edwards, CA), McDonnell Aircraft Company (St. Louis, MO), and Pratt & Whitney (West Palm Beach, FL) have developed and flight-tested an adaptive performance seeking control system which optimizes the quasi-steady-state performance of the F-15 propulsion system. This paper presents flight and ground test evaluations of the propulsion system parameter estimation process used by the performance seeking control system. The estimator consists of a compact propulsion system model and an extended Kalman filter. The extended Laman filter estimates five engine component deviation parameters from measured inputs. The compact model uses measurements and Kalman-filter estimates as inputs to predict unmeasured propulsion parameters such as net propulsive force and fan stall margin. The ability to track trends and estimate absolute values of propulsion system parameters was demonstrated. For example, thrust stand results show a good correlation, especially in trends, between the performance seeking control estimated and measured thrust

Credit report accuracy and access to credit

Data that credit-reporting agencies maintain on consumers' credit-related experiences play a central role in U.S. credit markets. Analysts widely agree that the data enable these markets to function more efficiently and at lower cost than would otherwise be possible. Despite the great benefits of the current system, however, some analysts have raised concerns about the accuracy, timeliness, completeness, and consistency of consumer credit records and about the effects of data problems on the availability and cost of credit. ; In this article, the authors expand on the available research by quantifying the effects of credit record limitations on the access to credit. Using the credit records of a nationally representative sample of individuals, the authors examine the possible effects of data problems on consumers by estimating the changes in consumers' credit history scores that would result from "correcting" the problems in their credit records. Moreover, the authors report results for consumer groups segmented by strength of credit history (credit history score range), depth of credit history (number of credit accounts in a credit record), and selected demographic characteristics.Credit cards

An overview of consumer data and credit reporting

For some time, the Board of Governors of the Federal Reserve System has sought to obtain more detailed and timely information on the debt status, loan payment behavior, and overall credit quality of U.S. consumers. For decades, information of this type has been gathered by credit reporting companies primarily to assist creditors in evaluating the credit quality of current and prospective customers. To evaluate the potential usefulness of these data, the Federal Reserve Board engaged one of the three national consumer reporting companies to supply the credit records, without personal identifying information, of a nationally representative sample of individuals. This article describes the way the credit reporting companies compile and report their data and gives background on the regulatory structure governing these activities. This description is followed by a detailed look at the information collected in credit reports. Key aspects of the data that may be incomplete, duplicative, or ambiguous as they apply to credit evaluation are highlighted in the analysis. The article concludes with a discussion of steps that might be taken to address some of the issues identified. ; Also identified as FRB Philadelphia Payment Cards Center Discussion Paper 03-03Credit cards ; Consumer behavior

Changes in the distribution of banking offices

The past twenty years have been marked by major structural and regulatory changes in the banking industry. This article explores the relationships between these changes and the distribution of "brick and mortar" banking offices between 1975 and 1995. The analysis explores how population shifts, deregulation, and mergers, acquisitions, and failures may have influenced changes in the number and location of banking offices. Special attention is given to changes in banking office distributions across neighborhoods grouped by the median income of their residents and their central city, suburban, or rural location.Banks and banking ; Banking structure

Three dimensional origin of Godel spacetimes and black holes

We construct Godel-type black hole and particle solutions to Einstein-Maxwell theory in 2+1 dimensions with a negative cosmological constant and a Chern-Simons term. On-shell, the electromagnetic stress-energy tensor effectively replaces the cosmological constant by minus the square of the topological mass and produces the stress-energy of a pressure-free perfect fluid. We show how a particular solution is related to the original Godel universe and analyze the solutions from the point of view of identifications. Finally, we compute the conserved charges and work out the thermodynamics.Comment: 11 pages, 5 figures, twocolumn revtex style, reference added, acknowledgments correcte

First Description of the Nest and Eggs of the Moss-Backed Tanager (Buthraupis [Bangsia] Edwardsi)

This is the published version. Copyright Central Ornithology Publication Offic

KYRT1, a Disarmed Version of a Highly Tumorigenic \u3cem\u3eAgrobacterium Tumefaciens\u3c/em\u3e Strain Identified as Chry5

Disarmed A. tumefaciencs strain KYRT1, derived from a highly tumorigenic strain identified as A. tumefaciens strain Chry5. Disarming is accomplished by inactivation of plasmid pTiChry5 T-DNA sequences by, for example, deletion of sequences comprising the T-DNA right border. Methods of making transgenic plants using the novel A. tumefaciens strains are also provided