This study is concerned with the feasibility of the equation of motion considering dynamic relative displacement between support points. It provides an experimental result of a testing frame structure under dynamic relative displacement and simulation of the dynamic behavior using the equation. The results showed that the simulation could represent the dynamic behavior of the frame under relative displacement between support points and it could be concluded that the analytical method could...
Topics: Equation of Motion, Inertial Force, Relative Displacement, Non-Linear Dynamic Response Analysis
Modal analysis helps to determine the system frequencies and to obtain the eigen modes of various structural members subjected to vibration. In this research, modal analysis and harmonic analysis of a cantilever beam with different sections of same weight and material i.e., rectangle, T-section and I-section are carried out using ANSYS software to see the mode shapes and to observe the dynamic response of the cantilever beam and to identify the best configuration of the beam.
Topics: Modal Analysis, Mode Shapes, Natural Frequencies, Harmonic Analysis, Dynamic Response & Ansys
99
99
Jul 31, 2017
07/17
by
© IASET
texts
eye 99
favorite 0
comment 0
As the seismic load acting on a structure is a function of the self-weight of the structure, these structures are made comparatively light and flexible, which have relatively low natural damping. Results make the structures more vibration prone. New generation high rise building is equipped with an artificial damping device for vibration control through energy dissipation. A tuned mass damper is a device consisting of a mass, a spring, and a damper that is attached to a structure in order to...
Topics: dampers, dynamic response, flexibility, frequency, spring, Time history, Tuned mass
135
135
May 30, 2011
05/11
by
Griffin, T. P.; Naylor, G. R.; Haskell, W. D.; Breznik, G. S.; Mizell, C. A
texts
eye 135
favorite 0
comment 0
This paper presents an on-line mass spectrometer designed to monitor for cryogenic leaks on the Space Shuttle. The topics include: 1) Hazardous Gas Detection Lab; 2) LASRE Test Support; 3) Background; 4) Location of Systems; 5) Sample Lines for Gas Detection; 6) Problems with Current Systems; 7) Requirements for New System (Nitrogen and Helium Background); and 8) HGDS 2000. This paper is in viewgraph form.
Topics: THERMODYNAMICS, ACOUSTIC PROPAGATION, NOISE REDUCTION, THERMAL BUCKLING, FABRICATION, DYNAMIC...
240
240
May 23, 2011
05/11
by
Reddy, D. R.; Lafe, O.; Cheng, A. H-D
texts
eye 240
favorite 0
comment 0
Using global interpolation functions (GIF's), boundary element solutions are obtained for two- and three-dimensional viscous flows. The solution is obtained in the form of a boundary integral plus a series of global basis functions. The unknown coefficients of the GIF's are determined to ensure the satisfaction of the governing equations at selected collocation points. The values of the coefficients involved in the boundary integral equations are determined by enforcing the boundary conditions....
Topics: KALMAN FILTERS, MULTISENSOR FUSION, GRAVIMETRY, ATTITUDE (INCLINATION), DYNAMIC RESPONSE, LINE OF...
232
232
Jun 13, 2011
06/11
by
Vinnikov, Konstantin Y.; Cavalieri, Donald J.; Parkinson, Claire L
texts
eye 232
favorite 0
comment 0
For more than three decades now, satellite passive microwave observations have been used to monitor polar sea ice. Here we utilize sea ice extent trends determined from primarily satellite data for both the Northern and Southern Hemispheres for the period 1972(73)-2004 and compare them with results from simulations by eleven climate models. In the Northern Hemisphere, observations show a statistically significant decrease of sea ice extent and an acceleration of sea ice retreat during the past...
Topics: DYNAMIC STRUCTURAL ANALYSIS, ROTOR DYNAMICS, TURBOMACHINERY, DYNAMIC RESPONSE, ROTATING SHAFTS, GAS...
229
229
May 27, 2011
05/11
by
Lin, Shu; Zhang, Yu; Nakamura, Eric B.; Uehara, Gregory T
texts
eye 229
favorite 0
comment 0
Block codes have trellis structures and decoders amenable to high speed CMOS VLSI implementation. For a given CMOS technology, these structures enable operating speeds higher than those achievable using convolutional codes for only modest reductions in coding gain. As a result, block codes have tremendous potential for satellite trunk and other future high-speed communication applications. This paper describes a new approach for implementation of the synchronization function for block codes....
Topics: AEROACOUSTICS, CYLINDRICAL BODIES, DYNAMIC RESPONSE, FAR FIELDS, FLUTTER, NONLINEARITY,...
236
236
Jul 11, 2010
07/10
by
Brune, G. W.; Weber, J. A.; Johnson, F. T.; Lu, P.; Rubbert, P. E
texts
eye 236
favorite 0
comment 0
A method of predicting forces, moments, and detailed surface pressures on thin, sharp-edged wings with leading-edge vortex separation in incompressible flow is presented. The method employs an inviscid flow model in which the wing and the rolled-up vortex sheets are represented by piecewise, continuous quadratic doublet sheet distributions. The Kutta condition is imposed on all wing edges. Computed results are compared with experimental data and with the predictions of the leading-edge suction...
Topics: CONTROL THEORY, DYNAMIC RESPONSE, SCALE MODELS, COMPLEXITY, COORDINATION, DECISION MAKING,...
1,040
1.0K
Jul 11, 2010
07/10
by
Coleman, R. G.; Johnson, F. T.; Lu, P
texts
eye 1,040
favorite 0
comment 0
For abstract, see N75-32026.
Topics: CONTROL THEORY, DYNAMIC RESPONSE, AUTOMATIC CONTROL, CONTROLLABILITY, DECISION MAKING, DYNAMIC...
882
882
Jun 15, 2011
06/11
by
Tindle, E. L.; Manning, L. A.; Sadin, S. R.; Edsinger, L. E.; Weissman, P. R.; Swenson, B. L
texts
eye 882
favorite 0
comment 0
For abstract, see Vol. 1
Topics: ARTIFICIAL SATELLITES, SPACE SHUTTLES, TETHERING, COMPUTER PROGRAMS, DYNAMIC RESPONSE, EQUATIONS OF...
276
276
Jun 27, 2010
06/10
by
Jaffe, P
texts
eye 276
favorite 0
comment 0
Planar and nonplanar dynamic stability coefficient using biplanar wind tunnel, free flight system
Topics: FOURIER-BESSEL TRANSFORMATIONS, IMAGES, SAMPLING, SCATTERING AMPLITUDE, THEOREM PROVING, AIRY...
189
189
Jul 26, 2010
07/10
by
Weir, Lois J.; Reddy, D. R
texts
eye 189
favorite 0
comment 0
Flow through a high-speed, nominally two-dimensional inlet is characterized by highly complex, three-dimensional flow phenomena including strong secondary flows and shock/boundary layer interactions. Experimental and analytical data are presented for a Mach 5 mixed compression inlet that exhibits such three-dimensional flow characteristics. The two-dimensional inlet model, designed to provide performance information in the Mach 3 to 5 speed range for an over-under turbojet plus ramjet...
Topics: DYNAMIC STRUCTURAL ANALYSIS, DYNAMIC CONTROL, DYNAMIC RESPONSE, INTERNATIONAL COOPERATION, NASTRAN,...
275
275
Jul 23, 2010
07/10
by
Creighton, Tom; Haddad, Rafael; Hendrich, Louis; Hensley, Doug; Morgan, Louise; Russell, Mark; Swift, Jerr
texts
eye 275
favorite 0
comment 0
The acquisition costs determined for the NASA family of commute airplanes are presented. The costs of the baseline designs are presented along with the calculated savings due to the commonality in the family. A sensitivity study is also presented to show the major drivers in the acquisition cost calculations. The baseline costs are calculated with the Nicolai method. A comparison is presented of the estimated costs for the commuter family with the actual price for existing commuters. The cost...
Topics: DYNAMIC RESPONSE, INTEGRATED CIRCUITS, LASER OUTPUTS, PHOTOMETERS, HIGH ELECTRON MOBILITY...
921
921
May 21, 2011
05/11
by
Scott, Robert C.; Pototzky, Anthony S
texts
eye 921
favorite 0
comment 0
High speed linear aerodynamic theories like piston theory and Newtonian impact theory are relatively inexpensive to use for flutter analysis. These theories have limited areas of applicability depending on the configuration and the flow conditions. In addition, these theories lack the ability to capture viscous, shock, and real gas effects. CFD methods can model all of these effects accurately, but the unsteady calculations required for flutter are expensive and often impractical. This paper...
Topics: AIRCRAFT CONTROL, DYNAMIC RESPONSE, ENGINE CONTROL, GROUND EFFECT (AERODYNAMICS), THRUST,...
260
260
May 22, 2011
05/11
by
Litt, Jonathan; Wong, Edmond; Simon, Donald L
texts
eye 260
favorite 0
comment 0
A prototype Lisp-based soft real-time object-oriented Graphical User Interface for control system development is presented. The Graphical User Interface executes alongside a test system in laboratory conditions to permit observation of the closed loop operation through animation, graphics, and text. Since it must perform interactive graphics while updating the screen in real time, techniques are discussed which allow quick, efficient data processing and animation. Examples from an...
Topics: CONTROL THEORY, DYNAMIC LOADS, END EFFECTORS, FEEDBACK, MANIPULATORS, ROBOTICS, COMPUTERIZED...
337
337
May 23, 2011
05/11
by
Tartabini, P. V.; Striepe, S. A.; Powell, R. W
texts
eye 337
favorite 0
comment 0
Mars trajectory design options were examined that would accommodate a premature termination of a nominal manned opposition class mission for opportunities between 2010 and 2025. A successful abort must provide a safe return to Earth in the shortest possible time consistent with mission constraints. In this study, aborts that provided a minimum increase in the initial vehicle mass in low Earth orbit (IMLEO) were identified by locating direct transfer nominal missions and nominal missions...
Topics: SPLINE FUNCTIONS, ACTUATORS, DONNELL EQUATIONS, RESONANT FREQUENCIES, DYNAMIC RESPONSE,...
288
288
Sep 20, 2010
09/10
by
Brinker, David J.; Flood, Dennis J
texts
eye 288
favorite 0
comment 0
The development of an advanced photovoltaic power system that would have application for a manned lunar base is currently planned under the Surface Power element of Pathfinder. Significant mass savings over state-of-the-art photovoltaic/battery systems are possible with the use of advanced lightweight solar arrays coupled with regenerative fuel cell storage. The solar blanket, using either ultrathin GaAs or amorphous silicon solar cells, would be integrated with a reduced-g structure....
Topics: CONTROLLERS, DYNAMIC CONTROL, FLEXIBLE BODIES, STRUCTURAL DESIGN, DYNAMIC RESPONSE, FEEDBACK...
357
357
Jun 27, 2010
06/10
by
Kockarts, G., et al
texts
eye 357
favorite 0
comment 0
No Abstract Available
Topics: DYNAMIC RESPONSE, FUEL FLOW, MATHEMATICAL MODELS, RAMJET ENGINES, FEEDBACK CONTROL, LAPLACE...
502
502
Jun 2, 2011
06/11
by
Green, Mike; Davies, Carol B; Prabhu, Dinesh; Palmer, Grant; Loomis, Mark P.; Venkatapathy, Ethiraj; Kontinos, Dean; Henline, William; Polsky, Susan; Papadopoulos, Periklis
texts
eye 502
favorite 0
comment 0
The X-34 vehicle will provide the first flight demonstration under NASA's Reusable Launch Vehicle (RLV) program of a fully reusable launch vehicle. Under a fixed-price contract with NASA, Orbital Sciences Corporation (OSC) i s to provide a Mach 8 suborbital RLV technology demonstrator. The vehicle i s 18.3 meters in length, has a wingspan of 8.4 meters, and is powered by a single LOX-kerosene engine. The X-34 i s carried below an L-101 1 aircraft to an altitude in excess of 9 kilometers, where...
Topics: DESIGN ANALYSIS, FLUID DYNAMICS, DYNAMIC STRUCTURAL ANALYSIS, PIEZOELECTRIC ACTUATORS,...
287
287
Jun 13, 2011
06/11
by
Litt, Jonathan S
texts
eye 287
favorite 0
comment 0
A new linear point design technique is presented for the determination of tuning parameters that enable the optimal estimation of unmeasured engine outputs such as thrust. The engine s performance is affected by its level of degradation, generally described in terms of unmeasurable health parameters related to each major engine component. Accurate thrust reconstruction depends upon knowledge of these health parameters, but there are usually too few sensors to be able to estimate their values....
Topics: AEROELASTICITY, DYNAMIC RESPONSE, FLIGHT TESTS, FLUTTER, SPECTRAL METHODS, SPECTRUM ANALYSIS, F-18...
282
282
Jun 20, 2010
06/10
by
Higdon, D. T
texts
eye 282
favorite 0
comment 0
Approximation method for determining response of nonlinear dynamic systems to random disturbances
Topics: APPROXIMATION, DYNAMIC RESPONSE, NONLINEAR SYSTEM, RANDOM LOAD, COVARIANCE, DYNAMIC RESPONSE,...
413
413
Jul 5, 2010
07/10
by
Clevenson, S. A
texts
eye 413
favorite 0
comment 0
No Abstract Available
Topics: AIRCRAFT CONTROL, DYNAMIC RESPONSE, FLIGHT TESTS, TRANSFER FUNCTIONS, AIRCRAFT STABILITY,...
143
143
May 23, 2011
05/11
by
Deere, Karen A.; Asbury, Scott C
texts
eye 143
favorite 0
comment 0
A translating throat single expansion-ramp nozzle (SERN) concept was designed to improve the off-design performance of a SERN with a large, fixed expansion ratio. The concept of translating the nozzle throat provides the SERN with a variable expansion ratio. An experimental and computational study was conducted to predict and verify the internal performance of this concept. Three nozzles with expansion ratios designed for low, intermediate, and high Mach number operating conditions were tested...
Topics: ROTARY WING AIRCRAFT, CONTROL SYSTEMS DESIGN, FLIGHT CONTROL, MIMO (CONTROL SYSTEMS), DYNAMIC...
The response of small tunnel thrusters to triangular and square wave changes in applied voltages to the thruster motor is studied. Previous mathematical models have attempted to identify the dynamic characteristics in thruster responses in order to minimize limit cycling in underwater vehicle position control. These experiments validate the effect of fluid inertia in the tunnel for long and shorter period commands. Additionally, the presence of a transient lag between changes in propeller speed...
Topics: Thrusters, Dynamic response, Autonomous underwater vehicles (AUV)
401
401
Jul 26, 2010
07/10
by
Lieblein, Seymou
texts
eye 401
favorite 0
comment 0
No Abstract Available
Topics: AIRCRAFT LANDING, FIGHTER AIRCRAFT, FLIGHT TESTS, TURBOCOMPRESSORS, AIRCRAFT PERFORMANCE, APPROACH...
284
284
Jul 6, 2010
07/10
by
Wright, P. E
texts
eye 284
favorite 0
comment 0
Requirements and development of standards for occupational medicine support of personnel in the Lunar Receiving Laboratory (LRL) are outlined. Considered are proper personnel performance and exclusion of people prone to develop a serious illness within the quarantine area. Occupational medicine report for the LRL consists of examination procedures covering laboratory work, periodic examinations, immunizations, health maintenance, preventive practices, medical standards, and waiver authority.
Topics: CALIBRATING, ENERGY BANDS, SPECTROGRAPHS, WAVELENGTHS, DYNAMIC RESPONSE, OPTICAL MEASUREMENT, STARS
266
266
May 22, 2011
05/11
by
Defacio, Brian; Kim, S.-H.; Vannevel, A
texts
eye 266
favorite 0
comment 0
The squeezed states or Bogoliubov transformations and wavelets are applied to two problems in nonrelativistic statistical mechanics: the dielectric response of liquid water, epsilon(q-vector,w), and the bubble formation in water during insonnification. The wavelets are special phase-space windows which cover the domain and range of L(exp 1) intersection of L(exp 2) of classical causal, finite energy solutions. The multiresolution of discrete wavelets in phase space gives a decomposition into...
Topics: AEROSPACE SYSTEMS, AIRCRAFT ENGINES, DYNAMIC STRUCTURAL ANALYSIS, LIFE (DURABILITY), PROPULSION...
705
705
May 28, 2011
05/11
by
Chen, Philip T.; Thomson, Shaun; Woronowicz, Michael S
texts
eye 705
favorite 0
comment 0
Molecular and particulate contaminants generated from the operations of a propulsion system may impinge on spacecraft critical surfaces. Plume depositions or clouds may hinder the spacecraft and instruments from performing normal operations. Firing thrusters will generate both molecular and particulate contaminants. How to minimize the contamination impact from the plume becomes very critical for a successful mission. The resulting effect from either molecular or particulate contamination of...
Topics: SPRINGS (ELASTIC), ANGLE OF ATTACK, DYNAMIC PRESSURE, SWEEP ANGLE, RECTANGULAR PLANFORMS,...
179
179
Jul 12, 2010
07/10
by
Dressler, R. F
texts
eye 179
favorite 0
comment 0
The transient and steady thermal convection in microgravity is described. The approach is applicable to many three dimensional flows in containers of various shapes with various thermal gradients imposed. The method employs known analytical solutions to two dimensional thermal flows in simpler geometries, and does not require recourse to numerical calculations by computer.
Topics: ANTENNA COMPONENTS, DEGREES OF FREEDOM, DYNAMIC RESPONSE, FLEXIBLE BODIES, SPACE SHUTTLE ORBITERS,...
785
785
May 27, 2011
05/11
by
Hansen, C. Frederic
texts
eye 785
favorite 0
comment 0
Approximations are presented for the thermodynamic and transport properties of high-temperature air. Compressibility, enthalpy, entropy, the specific heats, the speed of sound, the coefficients of viscosity and thermal conductivity, and the Prandtl number for air are tabulated from 500 to 15,000 K over a range of pressures from 0.0001 to 100 atmospheres.
Topics: COMPUTATIONAL FLUID DYNAMICS, DYNAMIC RESPONSE, DIFFERENTIAL EQUATIONS, AERODYNAMIC COEFFICIENTS,...
232
232
Jun 3, 2011
06/11
by
Weiser, Erik S.; SaintClair, Terry L.; Nemeth, Michael P
texts
eye 232
favorite 0
comment 0
The use of foam insulation on the External Tank (ET) was necessitated by the potentially hazardous build up of ice on the vehicle prior to and during launch. This use of foam was initiated on the Saturn V rocket, which, like the Space Shuttle, used cryogenic fuel. Two major types of foam have been used on the ET. The first type is NCFI 24-124, an acreage material that is automatically sprayed on in a controlled environment. It replaced CPR 488 in 1998 and has been used since that time. The...
Topics: DESIGN ANALYSIS, PAYLOADS, DYNAMIC RESPONSE, SPACE SHUTTLE ORBITERS, CLEARANCES, RAPID PROTOTYPING
1,431
1.4K
Jun 19, 2010
06/10
by
Perelman, Ya. I
texts
eye 1,431
favorite 0
comment 0
Galerkin method for solutions of structural mechanics problems and theory of elasticity
Topics: CALCULUS OF VARIATIONS, STRUCTURAL DYNAMICS, VARIATIONAL CALCULUS, DYNAMIC RESPONSE, DYNAMIC...
321
321
May 30, 2011
05/11
by
Walthall, Charles L.; Loechel, Sara; Halthore, Rangasay
texts
eye 321
favorite 0
comment 0
The BOREAS RSS-3 team collected and processed helicopter-based measurements of atmospheric conditions to estimates of aerosol optical thickness and atmospheric water vapor. The automatic sun-tracking photometer for helicopters was deployed during all three 1994 IFCs at numerous tower and auxiliary sites in both the NSA and the SSA. Six spectral channels (440, 540, 613, 670, 870, and 1030 nm) were chosen to span the visible and NIR wavelengths and to avoid gaseous absorption. One additional...
Topics: SPACEBORNE EXPERIMENTS, OPTIMAL CONTROL, DATA TRANSMISSION, DYNAMIC RESPONSE, VIBRATION ISOLATORS,...
Bell System Technical Journal, 44: 10. December 1965 pp 2409-2431. Transient Motion of Circular Elastic Plates Subjected to Impulsive and Moving Loads. (Weiner, R.S.)
Topics: plate, loading, elastic, pressure, transient, deflection, wave, circular, sweeping, function,...
Bell System Technical Journal, 46: 2. February 1967 pp 319-356. Dynamic Response of Systems of Mutually Synchronized Oscillators. (Brilliant, M.B.)
Topics: response, frequency, station, filters, bilateral, unilateral, system, disturbance, phase, jitter,...
Bell System Technical Journal, 47: 2. February 1968 pp 227-259. Organic Synchronization: Design of the Controls and Some Simulation Results. (Candy, J.C.; Karnaugh, M.)
Topics: delay, frequency, buffer, controls, buffers, control, organic, synchronization, transmission,...
244
244
Jun 21, 2010
06/10
by
Bamberger, M.; Boeck, F
texts
eye 244
favorite 1
comment 0
Portable emergency oxygen generator based on reaction of alkali peroxides with water vapor for self-rescue from carbon monoxide poisoning
Topics: DYNAMIC RESPONSE, HONEYCOMB STRUCTURES, IMPACT LOADS, STATIC LOADS, ENERGY DISSIPATION, IMPACT...
385
385
Jul 6, 2010
07/10
by
Okda, J
texts
eye 385
favorite 0
comment 0
To express the noise reducing effect of a muffler in terms of the difference in the sound power levels radiated from the tailpipe exit with and without the muffler in the system, equations are deduced by means of the four-terminal constants (A B C D) of the equivalent electrical network of the whole muffler system. Measured curves are in good agreement with those obtained by graphical methods so far as the sound wave in the chamber can be regarded as a plane wave. In the higher frequency range...
Topics: HARMONIC MOTION, HUMAN REACTIONS, OPERATOR PERFORMANCE, RANDOM VIBRATION, DYNAMIC RESPONSE, MAN...
377
377
Jul 26, 2010
07/10
by
Umland, Jeffrey W.; Inman, Daniel J
texts
eye 377
favorite 0
comment 0
The vibration of an experimental flexible space truss is controlled with internal control forces produced by several proof mass actuators. Four candidate control law strategies are evaluated in terms of performance and robustness. These control laws are experimentally implemented on a quasi free-free planar truss. Sensor and actuator dynamics are included in the model such that the final closed loop is self-equilibrated. The first two control laws considered are based on direct output feedback...
Topics: AERODYNAMIC FORCES, UNSTEADY AERODYNAMICS, BUCKLING, COMPUTER GRAPHICS, DAMPING, DIVERGENCE,...
308
308
Jul 21, 2010
07/10
by
Springer, H.; Ecker, H.; Gunter, E. J
texts
eye 308
favorite 0
comment 0
The influence of bearing misalignment upon the dynamic characteristics of statistically indeterminant rotor bearing systems is investigated. Both bearing loads and stability speed limits of a rotor may be changed significantly by magnitude and direction of bearing misalignment. The useful theory of short journal bearings is introduced and simple analytical expressions, governing the misalignment problem, are carried out. Polar plots for the bearing load capacities and stability maps, describing...
Topics: ANTIFRICTION BEARINGS, STIFFNESS, SWIRLING, HYDROSTATIC PRESSURE, ROTARY STABILITY, ROTORS, DYNAMIC...
472
472
Jul 11, 2010
07/10
by
Hickox, C. E
texts
eye 472
favorite 1
comment 0
A study to investigate the hydraulic atomization characteristics of several novel injector designs for use in liquid propellant rocket engines is presented. The injectors were manufactured from a series of thin stainless steel platelets through which orifices were very accurately formed by a photoetching process. These individual platelets were stacked together and the orifices aligned so as to produce flow passages of prescribed geometry. After alignment, the platelets were bonded into a...
Topics: CONFERENCES, DYNAMIC RESPONSE, SCALE MODELS, CONTROL THEORY, DECISION MAKING, OPTIMAL CONTROL,...
750
750
Jul 11, 2010
07/10
by
Peasley, Q. D
texts
eye 750
favorite 0
comment 0
The exact coefficients for the explicit forms of the associated Legendre functions Pm for integer values of m,n=0,1,2,...25 are presented in tabular form together with two cross-referenced listings of the zeroes for these functions rounded to five decimal places. The unfactored coefficients and the interger coefficients are presented in adjacent columns for each function. The greatest common factor and divisor have been removed and listed separately for the integer coefficients.
Topics: DYNAMIC RESPONSE, EQUATIONS OF MOTION, MECHANICAL DEVICES, SUSPENSION SYSTEMS (VEHICLES), BANDS,...
295
295
May 31, 2011
05/11
by
Cavalieri, Donald J.; Markus, Thorsten; Ivanoff, Alvar
texts
eye 295
favorite 0
comment 0
As part of NASA's EOS Aqua sea ice validation program for the Advanced Microwave Scanning Radiometer (AMSR-E), Landsat 7 Enhanced Thematic Mapper (ETM) images were acquired to develop a sea ice concentration data set with which to validate AMSR-E sea ice concentration retrievals. The standard AMSR-E Arctic sea ice concentration product will be obtained with the enhanced NASA Team (NT2) algorithm. The goal of this study is to assess the accuracy to which the NT2 algorithm, using DMSP Special...
Topics: ROTARY WINGS, HARMONIC FUNCTIONS, DYNAMIC MODELS, HORIZONTAL FLIGHT, SYSTEM IDENTIFICATION,...
313
313
Jul 11, 2010
07/10
by
Briehl, D.; Reck, G. M
texts
eye 313
favorite 0
comment 0
In order to verify the ultraviolet absorption technique used in the Global Atmospheric Sampling Program, two flight experiments were conducted employing several techniques, both in situ and remote, for measuring atmospheric ozone. The first experiment used the NASA CV-990 equipped with an ultraviolet absorption ozone monitor and an ultraviolet spectrophotometer, a balloon ozonesonde, and a Dobson station for determining and comparing the ozone concentration data. A second experiment compared...
Topics: DYNAMIC RESPONSE, SOLID ROCKET PROPELLANTS, SPACE SHUTTLE BOOSTERS, VISCOELASTICITY, BOOSTER...
282
282
May 23, 2011
05/11
by
Kossentini, Faouzi; Chung, Wilson C.; Smith, Mark J. T
texts
eye 282
favorite 0
comment 0
This paper introduces an extension of entropy-constrained residual vector quantization (VQ) where intervector dependencies are exploited. The method, which we call conditional entropy-constrained residual VQ, employs a high-order entropy conditioning strategy that captures local information in the neighboring vectors. When applied to coding images, the proposed method is shown to achieve better rate-distortion performance than that of entropy-constrained residual vector quantization with less...
Topics: MAGNETOHYDRODYNAMICS, ENERGY LEVELS, STELLAR MASS, MAGNETIC FIELDS, VELOCITY DISTRIBUTION, DYNAMIC...
474
474
May 23, 2011
05/11
by
Krozel, Jimmy; Peters, Mark E.; Hunter, Georg
texts
eye 474
favorite 1
comment 0
With a Free Flight policy, the emphasis for air traffic control is shifting from active control to passive air traffic management with a policy of intervention by exception. Aircraft will be allowed to fly user preferred routes, as long as safety Alert Zones are not violated. If there is a potential conflict, two (or more) aircraft must be able to arrive at a solution for conflict resolution without controller intervention. Thus, decision aid tools are needed in Free Flight to detect and...
Topics: COMPUTATIONAL FLUID DYNAMICS, LOADS (FORCES), AEROSPACE INDUSTRY, DYNAMIC STRUCTURAL ANALYSIS,...
281
281
May 27, 2011
05/11
by
Fieno, Danie
texts
eye 281
favorite 0
comment 0
The lethargy-dependent equations of the consistent Pl approximation to the Boltzmann transport equation for slowing down neutrons have been used as the basis of an IBM 704 computer program. Some of the effects included are (1) linearly anisotropic center of mass elastic scattering, (2) heavy element inelastic scattering based on the evaporation model of the nucleus, and (3) optional variation of the buckling with lethargy. The microscopic cross-section data developed for this program covered...
Topics: LIQUID SLOSHING, DAMPING, BAFFLES, CYLINDRICAL TANKS, TRANSLATIONAL MOTION, AIRCRAFT STABILITY,...
210
210
Jun 9, 2011
06/11
by
Maestrello, Luci
texts
eye 210
favorite 0
comment 0
The control of shock noise or screech from a jet near a flexible structure is discussed. The pressure from the supersonic jet consists of a shock with spiral and flapping nonaxisymmetric modes superimposed on broadband response. This shock induces a nonlinear-nonstationary loading problem associated with acoustic wave generation and propagation coupled with structural vibration. Control of the shock is achieved by placing a ring at the nozzle lip oscillating at the shock fundamental frequency....
Topics: AEROELASTICITY, CONSERVATION LAWS, DYNAMIC PRESSURE, STIFFENING, TURBULENT FLOW, THREE DIMENSIONAL...
241
241
May 23, 2011
05/11
by
Garg, A.; Noebe, R. D.; Darolia, R
texts
eye 241
favorite 0
comment 0
Small additions of Hf to conventionally processed NiAl single crystals result in the precipitation of a high density of cuboidal G-phase along with a newly identified silicide phase. Both of these phases form in the presence of Si which is not an intentional alloying addition but is a contaminant resulting from contact with the ceramic shell molds during directional solidification of the single-crystal ingots. The morphology, crystal structure and Orientation Relationship (OR) of the silicide...
Topics: MAGNETIC FIELD RECONNECTION, BUBBLES, SOLAR MAGNETIC FIELD, FIELD ALIGNED CURRENTS, MAGNETIC FIELD...
Control systems were investigated in which the engine regulators and the attitude stabilizer blend well together. The engine initially studied was of the 280-hp Artouste turboprop type. Three simple configurations were analyzed by means of root locus procedures: (1) intergral control in the rpm feedback loop and proportional control in the temperature feedback loop; (2) proportional control in the rpm feedback loop and integral control in the temperature feedback loop; and (3) integral control...
Topics: DTIC Archive, Albachten, Hugh, MINNEAPOLIS-HONEYWELL REGULATOR CO MN AERONAUTICAL DIV,...
