25 Matching Results

Search Results

Criteria for Determination of Material Control and Accountability System Effectiveness

Description: The Nevada Test Site (NTS) is a test bed for implementation of the Safeguards First Principles Initiative (SFPI), a risk-based approach to Material Control & Accountability (MC&A) requirements. The Comprehensive Assessment of Safeguards Strategies (COMPASS) model is used to determine the effectiveness of MC&A systems under SFPI. Under this model, MC&A is divided into nine primary elements. Each element is divided into sub-elements. Then each sub-element is assigned two values, effectiveness and contribution, that are used to calculate the rating. Effectiveness is a measure of subelement implementation and how well it meets requirements. Contribution is a relative measure of the importance, and functions as a weighting factor. The COMPASS model provides the methodology for calculation of sub-element and element ratings, but not the actual criteria. Each site must develop its own criteria. For the rating to be meaningful, the effectiveness criteria must be objective and based on explicit, measurable criteria. Contribution (weights) must reflect the importance within the MC&A program. This paper details the NTS approach to system effectiveness and contribution values, and will cover the following: the basis for the ratings, an explanation of the contribution “weights,” and the objective, performance based effectiveness criteria. Finally, the evaluation process will be described.
Date: March 1, 2008
Creator: Wright, John
Partner: UNT Libraries Government Documents Department

High-speed wind-tunnel tests of a 1/16-scale model of the D-558 research airplane basic longitudinal stability of the D-558-1

Description: Report presenting the results of testing on a model of the D-558-1 in order to determine its pitching-moment, lift, and drag characteristics with no nose-inlet flow, and with the tail removed and at a constant setting. Only a limited analysis is provided.
Date: May 12, 1948
Creator: Wright, John B.
Partner: UNT Libraries Government Documents Department

High-speed wind-tunnel tests of a 1/16-scale model of the D-558 research airplane: D-588-1 speed-reduction brake and symmetrical-profile wing characteristics

Description: Report presenting the results of pitching-moment, lift, and drag measurements on a model of the D-558-1 with speed reduction brakes and a symmetrical profile wing at a range of Mach numbers. Only a small decrement in Mach number is produced with no nose-inlet flow and the speed-reduction brakes deflected.
Date: June 15, 1948
Creator: Wright, John B.
Partner: UNT Libraries Government Documents Department

High-speed wind-tunnel tests of a 1/16-scale model of the D-558 research airplane: longitudinal stability and control of the D-558-1

Description: Report presenting the results of pitching-moment and lift measurements on a model of the D-558-1 airplane with no nose-inlet flow at several tail and elevator settings at a range of Mach numbers. Information about the stability, control, and downwash results is provided.
Date: July 8, 1948
Creator: Wright, John B.
Partner: UNT Libraries Government Documents Department

High-Speed Wind-Tunnel Tests of a 1/16-Scale Model of the D-558 Research Airplane Lift and Drag Characteristics of the D-558-1 and Various Wing and Tail Configurations

Description: Tests were made in the Langley 8-foot high-speed tunnel to investigate the aerodynamic characteristics of the D-558-1 airplane and various wing and tail configurations on the D-558-1 fuselage. The various wing and tail configurations were tested to determine the aerodynamic effects of aspect ratio and sweep for suitable use on the second phase of the D-558 project (D-558-2). The tests were conducted through a speed range from a Mach number of 0.40 to approximately 0.94.This part of the investigation includes the lift and drag results available for the configurations tested at this rate. The D-558-1 results indicated that the lift force break would occur at a Mach number of 0.85 with some reduction in lift at speeds above this Mach number. Tests indicated that the airplane will have satisfactory lift and drag characteristics up to and including its design Mach number of 0.85. The 35deg sweptback, 35deg swept-forward, and low-aspect-ratio (2.0) wing configurations all showed pronounced improvements in maintaining lift throughout the Mach number range tested and in increasing the critical speeds above the D-558-1 value &itical to critical Mach numbers on the order of 0.9. Insofar as lift and drag characteristics are concerned level flight at speeds approaching the velocity of sound appears practical if swept or low-aspect-ratio configurations similar to those tested are used.
Date: 1953
Creator: Wright, John B. & Loving, Donald L.
Partner: UNT Libraries Government Documents Department

Longitudinal stability and control characteristics at high subsonic speeds of two models of a transonic research airplane with wings and horizontal tails of aspect ratios 4.2 and 2

Description: Report discussing an investigation of two transonic research airplane models at a range of Mach numbers and Reynolds numbers. The main difference between the models was the aspect ratio of the horizontal tail. Results regarding the stability, control, incremental horizontal-tail characteristics, downwash, horizontal-tail load, stability factors, and a tailless configuration are provided.
Date: September 29, 1950
Creator: Luoma, Arvo A. & Wright, John B.
Partner: UNT Libraries Government Documents Department

On the Reversibility of Newton-Raphson Root-Finding Method

Description: Reversibility of a computational method is the ability to execute the method forward as well as backward. Reversible computational methods are generally useful in undoing incorrect computation in a speculative execution setting designed for efficient parallel processing. Here, reversibility is explored of a common component in scientific codes, namely, the Newton-Raphson root-finding method. A reverse method is proposed that is aimed at retracing the sequence of points that are visited by the forward method during forward iterations. When given the root, along with the number of iterations, of the forward method, this reverse method is aimed at backtracking along the reverse sequence of points to finally recover the original starting point of the forward method. The operation of this reverse method is illustrated on a few example functions, serving to highlight the method's strengths and shortcomings.
Date: July 1, 2008
Creator: Perumalla, Kalyan S.; Wright, John P. & Kuruganti, Phani Teja
Partner: UNT Libraries Government Documents Department