34,687 research outputs found
Robot Display and Control program (ROBDAC)
The ROBOT display and control program (ROBDAC) to be written for the Adage 340 computer is designed to communicate with the Univac 1110 computer with the aid of the graphic support communications programs. ROBDAC and the Adage computer act as an input/output device for the program ROBOT, which is run on the Univac 1110. ROBDAC controls the input to ROBOT by displaying images of the inputs, providing an editing technique for these inputs, shipping the input data to the Univac, and then commanding ROBOT to start execution. The output is done in a similar manner after receiving the output data from the Univac. This data will be displayed numerically as well as by plotted graphs. All of the input/output will be done interactively with practically 'finger tip' control. A general program flow diagram of ROBDAC is included
Performance limitations of subband adaptive filters
In this paper, we evaluate the performance limitations of subband adaptive filters in terms of achievable final error terms. The limiting factors are the aliasing level in the subbands, which poses a distortion and thus presents a lower bound for the minimum mean squared error in each subband, and the distortion function of the overall filter bank, which in a system identification setup restricts the accuracy of the equivalent fullband model. Using a generalized DFT modulated filter bank for the subband decomposition, both errors can be stated in terms of the underlying prototype filter. If a source model for coloured input signals is available, it is also possible to calculate the power spectral densities in both subbands and reconstructed fullband. The predicted limits of error quantities compare favourably with simulations presented
A first order iteration process for simultaneous equations
First order iteration process for solutions of simultaneous equation
Use of similarity parameters for examination of geometry characteristics of high-expansion- ratio axial-flow turbines
Similarity parameters used for examining geometry characteristics of axial flow turbines with high expansion rati
Microstructure of interpass rolled wire + arc additive manufacturing Ti-6Al-4V components
Mechanical property anisotropy is one of the issues that are limiting the industrial adoption of additive manufacturing (AM) Ti-6Al-4V components. To improve the deposits’ microstructure, the effect of high-pressure interpass rolling was evaluated, and a flat and a profiled roller were compared. The microstructure was changed from large columnar prior beta grains that traversed the component to equiaxed grains that were between 56 and 139 μm in size. The repetitive variation in Widmanstätten alpha lamellae size was retained; however, with rolling, the overall size was reduced. A “fundamental study” was used to gain insight into the microstructural changes that occurred due to the combination of deformation and deposition. High-pressure interpass rolling can overcome many of the shortcomings of AM, potentially aiding industrial implementation of the process.EPSRC, AirBu
Investigation of low current gas tungsten arc welding using split anode calorimetry
Most previous split anode calorimetry research has applied high weld currents which exhibit
pseudo Gaussian distributions of arc current and power density. In this paper we investigate low
current arcs and show that both the current and power distributions have minima in the centre –
varying significantly from the expected Gaussian profile. This was postulated due to the
formation of the arc with the copper anode and the tungsten cathode. Furthermore, a number of
parameters were varied including the step size between measurements, anode thickness and
anode surface condition as well as cathode type and tip geometry. The step size between
measurements significantly influenced the distribution profile and the anode thickness needed to
be above 7 mm to obtain consistent results
Supercharged topping rocket propellant feed system
A rocket propellant feed system utilizing a bleed turbopump to supercharge a topping turbopump is presented. The bleed turbopump is of a low pressure type to meet the cavitation requirements imposed by the propellant storage tanks. The topping turbopump is of a high pressure type and develops 60 to 70 percent of the pressure rise in the propellant
Determining the Nonperturbative Collins-Soper Kernel From Lattice QCD
At small transverse momentum , transverse-momentum dependent parton
distribution functions (TMDPDFs) arise as genuinely nonperturbative objects
that describe Drell-Yan like processes in hadron collisions as well as
semi-inclusive deep-inelastic scattering. TMDPDFs naturally depend on the
hadron momentum, and the associated evolution is determined by the
Collins-Soper equation. For the corresponding
evolution kernel (or anomalous dimension) is nonperturbative and must be
determined as an independent ingredient in order to relate TMDPDFs at different
scales. We propose a method to extract this kernel using lattice QCD and the
Large-Momentum Effective Theory, where the physical TMD correlation involving
light-like paths is approximated by a quasi TMDPDF, defined using equal-time
correlation functions with a large-momentum hadron state. The kernel is
determined from a ratio of quasi TMDPDFs extracted at different hadron momenta.Comment: 9 pages, 2 figures; v2: extended the review of TMDPDF commonalities,
version submitted to PRD; v3: minor changes, journal versio
Portable, high intensity isotopic neutron source provides increased experimental accuracy
Small portable, high intensity isotopic neutron source combines twelve curium-americium beryllium sources. This high intensity of neutrons, with a flux which slowly decreases at a known rate, provides for increased experimental accuracy
Automatic holographic droplet analysis for liquid fuel sprays
The basic scheme for automated holographic analysis involves an optical system for reconstruction of the three dimensional real image of the droplet field, a spatial scanning system to transport a digitizing X-y image sensor through the real image, and processing algorithms for droplet recognition which establish the droplet sizes and positions. The hardware for system demonstrated includes the expanded and collimated beam from a 5 mW helium-neon laser for hologram reconstruction, an imaging lens for magnification of the real image field, and a video camera and digitizer providing 512-by-512 pixel resolution with 8-bit digitization. A mechanical stage is used to scan the hologram in three dimensional space, maintaining constant image magnification. A test droplet hologram is used for development and testing of the image processing algorithms
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