From the bitsavers.org collection, a scanned-in computer-related document. mit :: ai :: aim :: AIM-877

Topics: myr, frequency, frequencies, pluto, lines, secular, spectra, amplitude, planets, neptune, solar...

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Fortuna Podcast Episode 9! Your favorite boys Marshal and Ant are back this week to talk about fake sponsors, shitty music, and Pax East. We also discuss Seth Rogan and James Franco's movie The Interview and comedies in general. We share stories of us playing sports as kids to get girls and how one of us was put in the penalty box a lot. Check us out on Tumblr: Fortuna-Podcast.tumblr.com Shouts out to Emergen-C for not sponsoring the podcast.

Topics: Podcast, film, movies, video, games, gaming, job, for, a, cowboy, the, interview, seth, rogan,...

It is well known that the solution of the diffusion equation for an electromagnetic field with a time harmonic term, e(sup iwt), is in the form of a traveling wave whose amplitude attenuates over distance into a conducting medium. As the attenuation is an increasing function of frequency, the high frequency components attenuate more rapidly than those of low ones upon entering a well conducting object. At the same time, the phase velocity of an individual component is also an increasing...

Topics: NASA Technical Reports Server (NTRS), ELECTROMAGNETIC FIELDS, ELECTROMAGNETIC PULSES, WAVE...

Fast amplitude variations due to atmospheric scintillation are the main concerns for the Deep Space Network (DSN) Ka-band downlink under clear weather conditions. A theoretical study of the amplitude scintillation variances for a finite aperture antenna is presented. Amplitude variances for weak scattering scenarios are examined using turbulence theory to describe atmospheric irregularities. We first apply the Kolmogorov turbulent spectrum to a point receiver for three different turbulent...

Topics: NASA Technical Reports Server (NTRS), AMPLITUDE MODULATION, SCINTILLATION, ATMOSPHERIC TURBULENCE,...

Resonances or near resonances are ubiquitous among the excited nonradial pulsation modes of variable stars and they must play an important role in determining their pulsational behavior. Here in a first step at nonlinear asteroseismology, we explore some of the consequences of resonances by means of the amplitude equation formalism. We show how parity and angular momentum constraints can be used to eliminate many of the possible nonlinear resonant couplings between modes (and multiplets of...

Topics: NASA Technical Reports Server (NTRS), AMPLITUDE MODULATION, WHITE DWARF STARS, RESONANCE, VARIABLE...

The ferroelectric reflectarray is a new type of scanning antenna under development for space and ground communications and radar applications at the NASA Glenn Research Center. The reflectarray offers tremendous cost, gain, and efficiency advantages in comparison to the state-of-the-art phased arrays, but there is an inherent intersymbol interference (ISI) problem with digital communication data streams processed through the array because of the way the reflectarray is operated. This...

Topics: NASA Technical Reports Server (NTRS), ANTENNA ARRAYS, MATHEMATICAL MODELS, REFLECTOR ANTENNAS,...

The development of an instrumentation radar that uses a chirp waveform to achieve high range resolution is described. Such range resolution capability is required for two reasons: (1) to evaluate the response of targets to the operational waveforms used in high-performance radars; and (2) to obtain a means of separating the individual mechanisms that comprise the target scattering response to better understand the scattering process. This particular radar was efficiently constructed from a...

Topics: DTIC Archive, Dybdal,Robert B, AEROSPACE CORP EL SEGUNDO CA ELECTRONICS RESEARCH LAB, *SCATTERING,...

This thesis investigated a hybrid system for computing a position, scale, rotation invariant (PSRI) feature set. Specifically, the low order ordinary moments of a set of objects were optically calculated. This process required the production of computer generated holograms with amplitude transmittance. The detour phase hologram, a binary method, was used to produce the appropriate wavefronts of the a certain form. Each wavefront was imaged onto the object plane. The Fourier transform of the...

Topics: DTIC Archive, Robinson, Vicky L, AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF...

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Jun 21, 2010
06/10

by
Cole, D. Q

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Techniques for controlling warpage and residual stresses in welded aluminum alloy structures for Saturn project

Topics: COMPUTER PROGRAMS, ENERGY SPECTRA, LEAST SQUARES METHOD, PULSE AMPLITUDE, CONSTRAINTS, MATRICES...

An improved method of measuring chromatic dispersion in an optical fiber or other device affords a lower (relative to prior such methods) limit of measurable dispersion. This method is a modified version of the amplitude-modulation (AM) method, which is one of the prior methods. In comparison with the other prior methods, the AM method is less complex. However, the AM method is limited to dispersion levels . 160 ps/nm and cannot be used to measure the symbol of the dispersion. In contrast, the...

Topics: NASA Technical Reports Server (NTRS), OPTICAL FIBERS, AMPLITUDE MODULATION, LIGHT (VISIBLE...

The finite element method (FEM) is a numerical algorithm for solving second order differential equations. It has been successfully used to solve many problems in atomic and molecular physics, including bound state and scattering calculations. To illustrate the diversity of the method, we present here details of two applications. First, we calculate the non-adiabatic dipole polarizability of Hi by directly solving the first and second order equations of perturbation theory with FEM. In the...

Topics: NASA Technical Reports Server (NTRS), FINITE ELEMENT METHOD, DIFFERENTIAL EQUATIONS, ATOMIC...

A two-dimensional model of a constant-density diffusion-controlled reaction between unmixed species initially occupying adjacent half-spaces is formulated and analyzed. An axisymmetric viscous vortex field satisfying the Navier-Stokes equations winds up the interface between the species as they diffuse together and react. A flame-sheet approximation of the rapid reaction is made using a mixture fraction dependent variable. The problem was originally proposed by F. Marble, who performed a local...

Topics: DTIC Archive, Rehm, Ronald G, NATIONAL INST OF STANDARDS AND TECHNOLOGY GAITHERSBURG MD, *VORTICES,...

"This paper focuses mainly on Bit Error Rate BER , Signal to Noise Ratio and different Rayleigh channels. We have designed four Rayleigh channels. This paper describes the comparative analysis of different digital modulation techniques like BPSK, QPSK, 8PSK, 16PSK and 16QAM for four Rayleigh channels which are designed. We also compare the convolution coding with different code rates i.e. 1 2, 1 3 and 2 3 code rate for various channels. Here we use MATLAB2009b software. by Parvesh Kumar...

Topics: Computer Engineering, M-ARY Modulation, Quadrature Amplitude Modulation, Phase Shift Keying (PSK),...

We present a CCD survey of variable stars in the Draco dwarf spheroidal galaxy. This survey, which has the largest areal coverage since the original variable star survey by Baade & Swope, includes photometry for 270 RR Lyrae (RRL) stars, 9 anomalous Cepheids (ACs), 2 eclipsing binaries, and 12 slow, irregular red variables, as well as 30 background QSOs. Twenty-six probable double-mode RRL starswere identified. Observed parameters, including mean V and I magnitudes, V amplitudes, and...

Topics: DTIC Archive, Kinemuchi, K, NAVAL OBSERVATORY FLAGSTAFF AZ, *GALAXIES, *VARIABLE STARS, AMPLITUDE,...

The requirement for higher ultrasound resolution needed for early detection of breast tumors is to compensate distorted ultrasonic wavefronts. We have found that two types of algorithms are necessary to fully deaberrate ultrasonic waves in breast. One is a global algorithm for isotropic scattering, an example of which is time delay correction (TDC). In the last year we found that applying (TDC) type algorithms to Zn vitro breast data suppressed scattered energy and folded it into the target...

Topics: DTIC Archive, Zhu, Qing, PENNSYLVANIA UNIV PHILADELPHIA, *SPATIAL DISTRIBUTION, *SCATTERING,...

Propagation of seismic waves in the nearfield where rock rheology is demonstrably nonlinear raises unique difficulties. Nonlinearity arises primarily in two forms at intermediate to large strains: (1) nonlinear elasticity, and (2) amplitude-dependent attenuation. The proper representation of nonlinear constitutive equations for rocks in the regime is a potentially important ingredient of quantitative source models. We have shown previously that nonlinear one-dimensional wave propagation can...

Topics: DTIC Archive, Minster, Jean-Bernard, SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA INST OF...

Vertical plane response of submersible vehicles in the proximity of a free surface in deep water is evaluated using a potential flow, strip theory solver. Two criteria, that are periscope submergence, and sail broaching are used to quantify the response. These criteria combined with the vehicle's response amplitude operators in regular sinusoidal waves along with a statistical description of the seaway lead to an assessment of an overall operability index for the vehicle. This thesis presents a...

Topics: DTIC Archive, Celikel, A. K., NAVAL POSTGRADUATE SCHOOL MONTEREY CA, *PARAMETRIC ANALYSIS,...

Circadian activity rhythms that have been eliminated by lesions of the suprachiasmatic nucleus (SCN) can be restored by fetal SCN grafts. Partial lesions of the host allow simultaneous expression of both donor and host rhythm. Because partial SCN ablation produces characteristic changes in activity rhythms that are similar to those that occur with age, including shortened period, reduced amplitude, and fragmentation, we investigated the extent to which fetal SCN grafts may be expressed by an...

Topics: DTIC Archive, Ralph, Martin R., TORONTO UNIV (ONTARIO) DEPT OF PSYCHOLOGY, *CIRCADIAN RHYTHMS,...

The current-voltage relation within narrow auroral current sheets is examined through the use of high-resolution data from the high altitude Dynamics Explorer 1 satellite. The north-south perpendicular electric field and the east-west magnetic field are shown for three cases in which there are large amplitude, oppositely directed paired electric fields and narrow current sheets. These data are shown to indicate that there is a linear 'Ohm's law' relationship between the current density and the...

Topics: DTIC Archive, Weimer,D R, IOWA UNIV IOWA CITY DEPT OF PHYSICS AND ASTRONOMY, *IONOSPHERE, *AURORAE,...

During 1986, most of our efforts have concerned a better understanding of seismic sources and propagation on local and regional sismograms and m sub b optimum determination. The influence of source depth on local seismograms (10 - 60 km) has been carried on by using synthetic seisograms. Pg and Sg waves amplitudes are less influenced than Rg waves amplitudes by depth variations. Rg waves amplitudes are clearly decreasing when depth increases. We need to apply such a discriminant on real cases....

Topics: DTIC Archive, Massinon, B, RADIOMANA PARIS (FRANCE), *SEISMOLOGY, *WESTERN EUROPE, AMPLITUDE, DATA...

Reduction of noise and vibrations within structural systems has been a long standing problem. Recent studies have indicated that waveguide absorbers have been effective in the reduction of noise and vibrations over a broad frequency range. A waveguide absorber is a structure along which vibrational waves can travel. If the waveguide absorber is treated with an energy dissipation scheme, the amplitudes of the waves will decrease as they travel along the waveguide absorber. the test structure...

Topics: DTIC Archive, Horne, III, Charles T, NAVAL POSTGRADUATE SCHOOL MONTEREY CA, *METAL PLATES,...

A microprocessor-base set-up is fabricated and tested for the single particle calibration of the plastic scintillator. The single particle response of the scintillator is digitized by an A/D converter, and a 8085 A based microprocessor stores the pulse heights. The digitized information is printed. Facilities for CRT display and cassette storing and recalling are also made available.

Topics: NASA Technical Reports Server (NTRS), COSMIC RAY SHOWERS, DIGITAL SYSTEMS, MICROPROCESSORS, PULSE...

The development of the free electron laser (FEL) as a source of coherent radiation continues toward the fulfillment of its potential for high power, high efficiency and short wavelength. New experiments toward fulfillment of the FEL's potential present new phenomenon to be studied by theoreticians and experimentalists. Two of these phenomenon in short wavelength FELs are the shift in phase velocity resonance and the reduction in gain. The first part of this thesis presents an argument for the...

Topics: DTIC Archive, Bice, Carl A, NAVAL POSTGRADUATE SCHOOL MONTEREY CA, *LASERS, PHASE VELOCITY,...

Bell System Technical Journal, 5: 2. April 1926 pp 292-307. Directive Diagrams of Antenna Arrays. (Foster, Ronald M.)

Topics: antennae, diagrams, array, phase, arrays, antenna, amplitude, directive, diagram, separation,...

Bell System Technical Journal, 51: 1. January 1972 pp 165-207. Waiting Time Jitter. (Duttweiler, D.L.)

Topics: jitter, stuffing, waiting, spectrum, experimental, filtered, frequency, input, amplitude,...

An experimental program has been conducted to study interactions between acoustics waves and two types of non-uniform average flow occurring in solid propellant rockets. Measurements in a resonance tube confirmed the existence of an energy loss associated with interactions between a longitudinal acoustic field and an average flow entering through a lateral boundary. The measured loss was approximately five times as large as that predicted by a simple one-dimensional analysis. However, due to...

Topics: DTIC Archive, Culick,F E C, CALIFORNIA INST OF TECH PASADENA GUGGENHEIM JET PROPULSION CENTER, *GAS...

From the bitsavers.org collection, a scanned-in computer-related document. wavetek :: 130 Aug72

Topics: frequency, dial, output, selector, wave, wavetek, amplitude, freq, transistor, triangle, frequency...

From the bitsavers.org collection, a scanned-in computer-related document. wavetek :: 5380B Nov83

Topics: frequency, span, display, signal, cursor, input, amplitude, mode, channel, spectrum, front panel,...

Bell System Technical Journal, 18: 3. July 1939 pp 404-437. The Application of Negative Feedback to Frequency-Modulation Systems. (Chaffee, J.G.)

Topics: feedback, modulation, frequency, output, amplitude, wave, signal, noise, system, disturbance,...

Bell System Technical Journal, 30: 3. July 1951 pp 564-587. A Photographic Method for Displaying Sound Wave and Microwave Space Patterns. (Kock, W.E.; Harvey, F.K.)

Topics: lens, wave, sound, pattern, microwave, fronts, scanning, phase, signal, amplitude, loud speaker,...

Bell System Technical Journal, 47: 7. Septemember 1968 pp 1397-1422. Networks. (Drazy, E.J.; MacLean, R.C.; Sheehey, R.E.)

Topics: delay, filter, networks, frequency, mhz, microwave, loss, amplitude, insertion, equalizers, channel...

Bell System Technical Journal, 48: 10. December 1969 pp 3243-3263. Amplitude Distributions of Television Channel Noise and a Model for Impulse Noise. (Fennick, J.H.)

Topics: noise, impulse, distribution, data, distributions, waveform, median, count, amplitude, density,...

Bell System Technical Journal, 48: 6. July-August 1969 pp 1967-1998. Amplitude and Phase Modulation In Resistive Diode Mixers. (Dragone, C.)

Topics: frequency, diode, converter, equivalent, behavior, amplitude, equation, circuit, modulation,...

In a fading channel, bit error rate for frequency-shift- keying signals is determined predominantly by the envelope amplitude fading statistics of the signal. The narrowband envelope amplitude distributions are measured from the TREX04 data (as a function of frequency) using M-sequence signals centered at 17 kHz with a 5 kHz bandwidth. The results do not fit the Rayleigh, Rician, Nakagami m-distributions. In contrast, we find that the data are fitted well by a K-distribution. We also analyze...

Topics: DTIC Archive, NAVAL RESEARCH LAB WASHINGTON DC, *UNDERWATER ACOUSTICS, *FREQUENCY SHIFT KEYERS,...

Methods to filter and to analyze measured data are described and the numerical results are validated with the generated data. A lowpass filter is used to eliminate the noise of the measured data. The methods of zero crossing, sine function and spectral analysis are applied to compute the amplitudes, periods and phase angles. The numerical results of the measured data are compared with those of different methods. When the measured data are sinusoidal, the results analyzed with the three methods...

Topics: DTIC Archive, Hong, Young S, NAVAL SURFACE WARFARE CENTER CARDEROCK DIV BETHESDA MD, *COMPUTER...

The paper presents the first ever research and experimental results regarding the combination of a software-defined multi-Gbps modem and a broadband high power space amplifier when tested with an extended form of the industry standard DVB-S2 and LDPC rate 9/10 FEC codec. The modem supports waveforms including QPSK, 8-PSK, 16-APSK, 32-APSK, 64-APSK, and 128-QAM. The broadband high power amplifier is a space qualified traveling-wave tube (TWT), which has a passband greater than 3 GHz at 33 GHz,...

Topics: NASA Technical Reports Server (NTRS), BROADBAND AMPLIFIERS, EXTREMELY HIGH FREQUENCIES, MODEMS,...

R&D Report 1967-50 : Pulse-code modulation for high-quality sound-signal distribution: Appraisal of system requirements D. Howorth, D.E.L. Shorter For technical and economic reasons, the present network of lines used for distributing sound signals to transmitters at audio frequencies will eventually have to be replaced by some telecommunication system operating at frequencies above the audible range. For the immediate future, programme channels based on the existing carrier telephony...

Topics: signal, noise, transmission, quantizing, modulation, sample, ratio, system, coding, amplitude,...

Noise generator catalog March 1967 - Elgenco, Inc.

Topics: khz, output, volts, rms, amplitude, gaussian, spectral, noise, model, mhz, amplitude probability,...

System, consisting of sample and hold digital-to-analog converter, clock circuit, sample delay circuit, initial condition circuit and interpolator circuit, improves accuracy of reconstructed analog signal without increasing sample rates.

Topics: NASA Technical Reports Server (NTRS), ACCURACY, ANALOG SIMULATION, BANDWIDTH, DELAY CIRCUITS,...

By and large four wheeler vehicles are one of the well known vehicles in city transport. Four wheeler vehicles are presented to vibrations because of unpredictable surface of streets. This influences the well being and in addition inconvenience of the driver and travelers. The motions are moved into the group of driver and traveler through the body tissues, organs and frameworks of the individual causing different impacts on the structures inside the body before it is hosed and scattered. From...

Topics: NVH TESTING, SEAT EFFECTIVE AMPLITUDE TEST SEAT, TRANSFER PATH OF VIBRATIONS TO THE STEERING WHEEL,...

The status of the Joint University Program is given. Brief synopsis of some areas of research follow. The study of spectrum efficient methods for transmitting weather information to aircraft has resulted in definition of an improved amplitude and phase modulation process which permits reutilization of voice channels for both voice and data. The system is being implemented for testing. Multisensor navigation systems introduce increased flexibility and performance for aviation, at the expense of...

Topics: NASA Technical Reports Server (NTRS), AIR TRANSPORTATION, GLOBAL POSITIONING SYSTEM, INERTIAL...

Bell System Technical Journal, 25: 3. July 1946 pp 532-536. Abstracts of Technical Articles by Bell System Authors.

Topics: amplitude, radar, piezoelectric, relative, dielectric, attenuation, fungi, transmission,...

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Feb 23, 2019
02/19

by
Hessel, Sidi

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vii, 134 pages : 26 cm

Topics: Joints -- Range of motion, Exercise for women, Stretching exercises, Posture, Articulations --...

Bell System Technical Journal, 42: 3. May 1963 pp 637-679. Numerical Computation of Phase from Amplitude at Optical Frequenciesincluded on pages 667-679. (Thomas, D.E.)

Topics: phase, amplitude, summation, frequencies, computation, slope, optical, frequency, attenuation,...

Two nonlinear shoaling models describing the shoaling of unidirectional surface gravity waves are developed. The models, based on variants of the Boussinesq equations for a sloping bottom are cast as a set of coupled evolution equations for the amplitudes and phases of the Fourier modes of the wave field. Resonant and near resonant triad interactions across the entire wind-wave frequency band (0.05-0.25 Hz) provide the mechanism for nonlinear cross spectral energy transfers and phase...

Topics: DTIC Archive, Freilich,Michael Harris, SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA SHORE...

A research program in semiconductor lasers and related phenomena resulted in new understanding relating to coherent single lobe laser arrays and to structures displaying near-diffraction-limited output. Using our molecular beam epitaxial reactor, we have demonstrated new unstable resonator geometry of semiconductor laser which potentially are capable of producing large aperature high power without the need for arrays. Typical powers of approx. 0.4 Watt were demonstrated in a single mode. Basic...

Topics: DTIC Archive, Lindsey,C, CALIFORNIA INST OF TECH PASADENA DEPT OF APPLIED PHYSICS, *ELECTROOPTICS,...

Improvements to VHF air/ground communications for civil aviation in the 118-137 MHz aeronautical mobile frequency band are systematically explored by means of a decision tree approach. Seven individual papers analyze in detail the operational and technical factors involved in making these improvements. Basic tradeoffs between analog and digital modulation are discussed to frame the problem. Near-term improvements utilizing various analog modulations with closer channel spacing are first...

Topics: DTIC Archive, Chen, Cheng-Hong, MITRE CORP BEDFORD MA, *AIR TRAFFIC CONTROL SYSTEMS, *COMMUNICATION...

Oscillation of fuel composition in ducted air flows with oscillatory injection of gaseous fuel was studied using temperature difference as scalar in flows involving radial injection of an oscillatory fuel jet and radial and axial injection of a steady air-fuel jet with oscillatory fuel composition into a ducted air stream. Local measurements of mean and oscillatory velocity and scalar in turbulent flow were carried out with flow rates, frequency and amplitude of imposed oscillations as...

Topics: DTIC Archive, Wen-Li, F, NAVAL COMMAND CONTROL AND OCEAN SURVEILLANCE CENTER RDT AND E DIV SAN...

This project is a fundamental study of the basic dynamical mechanisms involved, and the consequent theoretical modelling approaches needed, in the generation and propagation of internal solitary waves across the continental shelf and slope.

Topics: DTIC Archive, LOUGHBOROUGH UNIV (UNITED KINGDOM), *CONTINENTAL SHELVES, *CONTINENTAL SLOPES,...

LONG-TERM GOALS. To determine the mechanisms of generation, propagation, dissipation, mixing and decay of large amplitude internal waves formed by tidal flow past topography. OBJECTIVES. Our objectives are to use both acoustic remote sensing and in situ profile observations of large amplitude internal waves, together with highly resolved numerical simulation, so as to develop a predictive understanding of their behavior, with application to their generation by flow past topography, their...

Topics: DTIC Archive, RHODE ISLAND UNIV NARRAGANSETT GRADUATE SCHOOL OF OCEANOGRAPHY, *ACOUSTIC DETECTORS,...