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Time and Frequency: Theory and Fundamentals

Description: From Abstract: "This is a tutorial Monograph describing various aspects of time and frequency (T/F). Included are chapters relating to elemental concepts of precise time and frequency; basic principles of quartz oscillators and atomic frequency standards; historical review, recent progress, and current status of atomic frequency standards; promising areas for developing future primary frequency standards; relevance of frequency standards to other areas of metrology including a unified standard concept; statistics of T/F data analysis coupled with the theory and construction of the NBS atomic time scale; an overview of T/F dissemination techniques; and the standards of T/F in the USA. The Monograph addresses both the specialist in the field as well as those desiring basic information about time and frequency."
Date: May 1974
Creator: Blair, Byron E.
Partner: UNT Libraries Government Documents Department

Microwave Spectral Tables: Volume 5. Spectral Line Listing

Description: From Abstract: "This volume is a listing of the spectral lines reported in Volume I, III, and IV of the Microwave Spectral Tables. These lines are listed according to ascending magnitude of frequency and should provide a steady reference."
Date: June 1968
Creator: Cord, Marian S.; Lojko, Matthew S. & Petersen, Jean D.
Partner: UNT Libraries Government Documents Department

Effect of the proximity of the wing first-bending frequency and the short-period frequency on the airplane dynamic-response factor

Description: Report presenting a study of the effect of the frequency of the lowest wing structural mode on the airplane center-of-gravity dynamic-response factor was made my employing simplified transfer functions.
Date: June 1958
Creator: Huss, Carl R. & Donegan, James J.
Partner: UNT Libraries Government Documents Department

Matrix method of determining the longitudinal-stability coefficients and frequency response of an aircraft from transient flight data

Description: From Summary: "A matrix method is presented for determining the longitudinal-stability coefficients and frequency response of an aircraft from arbitrary maneuvers. The method is devised so that it can be applied to time-history measurements of combinations of such simple quantities as angle of attack, pitching velocity, load factor, elevator angle, and hinge moment to obtain the over-all coefficients. Although the method has been devised primarily for the evaluation of stability coefficients which are of primary interest in most aircraft loads and stability studies, it can be used also, with a simple additional computation, to determine the frequency-response characteristics. The entire procedure can be applied or extended to other problems which can be expressed by linear differential equations."
Date: December 15, 1950
Creator: Donegan, James J. & Pearson, Henry A.
Partner: UNT Libraries Government Documents Department

Expected numbers of maxima and minima of a stationary random process with non-Gaussian frequency distribution

Description: Report presenting a method for calculating the expected number of maxima or minima of a random process with non-Gaussian frequency distribution from the statistical moments of the process and its first two derivatives. The effects of skewness and kurtosis can also be calculated provided the required moments are known.
Date: April 1957
Creator: Diederich, Franklin W.
Partner: UNT Libraries Government Documents Department

High-Frequency Voltage Measurement

Description: Fundamental principles and techniques used for voltage measurements primarily for frequencies in the upper audio- and radio-frequency ranges and including part of the ultrahigh frequency range.
Date: September 1, 1949
Creator: Selby, Myron C.
Partner: UNT Libraries Government Documents Department

The Detection of Short Circuits in Thermocouples by a Radio-Frequency Measurement of Inductance

Description: Abstract: "The development of a portable battery-operated instrument capable of detecting a short-circuit four or more inches from the hot junction of a five-foot-long thermocouple is described. The accuracy of measurement is inversely proportional to the length of the thermocouple and is not affected by changes in thermocouple temperature. A signal having a wave length much greater than the electrical length of the thermocouple is used to measure thermocouple inductance. The instrument consists of a radio-frequency ocillator, a bridge, five stages of amplification, and a director. Theoretical considerations are presented in support of a radio-frequency measurement."
Date: 1956
Creator: Morris, Peter R.
Partner: UNT Libraries Government Documents Department

Theoretical study of the lateral frequency response to gusts of a fighter airplane, both with controls fixed and with several types of autopilots

Description: Report presenting a theoretical approach to determine the lateral frequency response of a fighter airplane to side gusts and rolling gusts at a Mach number of 0.7 and an altitude of 30,000 feet. Frequency response and power spectral density were determined with the controls fixed and in combination with three different basic types of attitude autopilots.
Date: March 1956
Creator: Adams, James J. & Mathews, Charles W.
Partner: UNT Libraries Government Documents Department

A graphical method for plotting amplitude and phase angle of transfer functions of dynamic systems without factoring polynomials

Description: From Summary: "A method is presented for obtaining amplitude and single plots for rational algebraic functions of an imaginary variable. Application of the method is illustrated by an example in which the frequency response of an automatically controlled aircraft is plotted. The method involves the use of templets but does not require the factoring of polynomials."
Date: November 1951
Creator: Smith, Earl F.
Partner: UNT Libraries Government Documents Department

The calculation of modes and frequencies of a modified structure from those of the unmodified structure

Description: Report presenting a method that has been developed for the calculation of the natural coupled or uncoupled frequencies and modes of a structure with modifications directly from the known modes and frequencies of the unmodified structure. The method is advantageous when the modes and frequencies of the unmodified structure either are known or are required along with the modes and frequencies of the structure with various modifications.
Date: July 1950
Creator: Kruszewski, Edwin T. & Houbolt, John C.
Partner: UNT Libraries Government Documents Department

Frequency response of linear systems from transient data

Description: "Methods are presented that use general correlative time-response input and output data for a linear system to determine the frequency-response function of that system. These methods give an exact description of any linear system for which such transient data are available. Examples are shown of application of a method to both an underdamped and a critically damped exact second-order system, and to an exact first-order system with and without dead time. Experimental data for a turbine-propeller engine showing the response of engine speed to change in propeller-blade angle are presented and analyzed" (p. 547).
Date: April 1, 1949
Creator: Laverne, Melvin E. & Boksenbom, Aaron S.
Partner: UNT Libraries Government Documents Department

Probability and Frequency Characteristics of Some Flight Buffet Loads

Description: "The frequency characteristics and statistical properties of the buffet loads measured on the unswept wing and tail of a fighter airplane have been studied in the stall and in the shock regime. The results indicate that the wing loads in buffeting can be treated as the Gaussian response of a simple elastic system. The tail loads appear to represent a more complicated process" (p. 1).
Date: August 1956
Creator: Huston, Wilber B. & Skopinski, T. H.
Partner: UNT Libraries Government Documents Department

Theoretical Distribution of Slip Angles in an Aggregate of Face-Centered Cubic Crystals

Description: Note presenting an analysis of the relative frequency of occurrence of any given slip-line angle in a plastically deformed polycrystal composed of face-centered cubic crystals for the case of simple tension. The results are compared with those obtained for a polycrystal composed of crystals which have but a single mode of slip and with experimental results.
Date: August 1952
Creator: Hedgepeth, John M.
Partner: UNT Libraries Government Documents Department

Spectrum Policy in the Age of Broadband: Issues for Congress

Description: The convergence of wireless telecommunications technology and Internet protocols is fostering new generations of mobile technologies. This transformation has created new demands for advanced communications infrastructure and radio frequency spectrum capacity that can support high-speed, content-rich uses. This report considers the possibility of modifying spectrum policy: (1) to support national goals for broadband deployment by placing more emphasis on attracting new providers of wireless broadband services; and (2) to accommodate the wireless broadband needs of industries that are considered by many to be the economic drivers of the future, not only communications, but also areas such as energy, health care, transportation, and education.
Date: July 13, 2009
Creator: Moore, Linda K.
Partner: UNT Libraries Government Documents Department

Techniques for Estimating Magnitude and Frequency of Floods on Rural Unregulated Streams in New York State Excluding Long Island

Description: Abstract: Techniques are presented for estimating the magnitude and frequency of floods at ungaged sites on unregulated rural streams in New York, excluding Long Island. Discharge-frequency data and basin characteristics of 220 gaging stations in New York and adjacent states were used in multiple linear regression analysis to develop equations for floods that range in recurrence interval from 2 to 100 years. Separate equations were developed for northern, southeastern, and western regions of New York. Drainage area is the independent variable needed in all equations; other variables needed, depending on region, are main-channel slope, storage index, and mean annual precipitation. A method is given for obtaining improved discharge-frequency relationships qt gage sites by weighing log-Pearson Type III and regression estimates according to their variances. Basin characteristics, log-Pearson Type III statistics, and regression and weighted estimates of the discharge-frequency relationship are tabulated for the New York gaging stations used in the regression analysis.
Date: July 1979
Creator: Zembrzuski, Thomas J., Jr. & Dunn, Bernard
Partner: UNT Libraries Government Documents Department

Spectrum Policy in the Age of Broadband: Issues for Congress

Description: Report that discusses some of the commercial and federal radio frequency spectrum policy changes required by the Middle Class Tax Relief and Job Creation Act of 2012. It also summarizes new policy directions for spectrum management under consideration in the 112th Congress, such as the encouragement of new technologies that use spectrum more efficiently.
Date: August 29, 2012
Creator: Moore, Linda K.
Partner: UNT Libraries Government Documents Department