Subsonic Aerodynamic Characteristics of Pyramidal Re-entry Shapes Incorporating Variable Geometry
Aerodynamic characteristics of pyramidal reentry shapes with variable geometry, at subsonic speeds
REENTRY BODY↗
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Static stability characteristics of cone and half-cone-pyramid configurations at Mach 6.83
Longitudinal and static stability characteristics of cone and half-cone with rectangular pyramid configurations
STATIC STABILITY↗
Developing parallel GeoFEST(P) using the PYRAMID AMR library
The PYRAMID parallel unstructured adaptive mesh refinement (AMR) library has been coupled with the GeoFEST geophysical finite element simulation tool to support parallel active tectonics simulations. Specifically, we have demonstrated modeling of coseismic and postseismic surface displacement due to a simulated Earthquake for the Landers system of interacting faults in Southern California. The new software demonstrated a 25-times resolution improvement and a 4-times reduction in time to solution over the sequential baseline milestone case. Simulations on workstations using a few tens of thousands of stress displacement finite elements can now be expanded to multiple millions of elements with greater than 98% scaled efficiency on various parallel platforms over many hundreds of processors. Our most recent work has demonstrated that we can dynamically adapt the computational grid as stress grows on a fault. In this paper, we will describe the major issues and challenges associated with coupling these two programs to create GeoFEST(P). Performance and visualization results will also be described.
adaptive mesh refinement (AMR)↗
Static stability and control characteristics of two large-dihedral right triangular pyramid lifting reentry configurations at a Mach number of 3.05
Static stability and control characteristics of dihedral right triangular pyramid lifting reentry vehicle configurations
REENTRY VEHICLE↗
Reflection coefficients of pyramidal and H- plane horns radiating into dielectric materials
Reflection coefficients of pyramidal and H-plane horns under free-space conditions and with horns radiating onto slabs of plexiglass or quartz
Cockrell, C. R.↗
Comparison of the solar concentrating properties of truncated hexagonal, pyramidal and circular cones
The concentrating properties of specularly reflecting pyramids, hexagons and circular cones are examined. The concentration factor is determined as a function of the coefficient of reflection and the shape and orientation of the incident sunlight. Reflector designs allowing multiple reflections for both normal and oblique incidence are considered.
Burkhard, D. G.↗
Residential solar-heating system uses pyramidal optics
Report describes reflective panels which optimize annual solar energy collection in attic installation. Subunits include collection, storage, distribution, and 4-mode control systems. Pyramid optical system heats single-family and multi-family dwellings.
Source record↗
Installation, operation, and maintenance for the pyramidal optics solar system installed at Yacht Cover, Columbia, South Carolina
Information concerning the installation, operation, and maintenance of the pyramidal Solar System for space heating and domestic hot water is presented. Principles of operation, sequence of installation, and procedures for the operation and maintenance of each subsystem making up the solar system are presented. Troubleshooting charts and maintenance schedules are presented.
Source record↗
Design data brochure for a pyramidal optical solar system
A pyramidal optics solar system for solar heating and domestic hot water is described. The system is made up of the collecting, storage, and distribution subsystems. System description, available accessories, installation arrangements, physical data, piping and wiring diagrams, and guide specifications are included.
Source record↗
Pyramidal-Reflector Solar Heater
Motor-driven reflector compensates for seasonal changes in Sun's altitude. System has flat-plate absorbers mounted on north side of attic interior. Skylight window on south-facing roof admits Sunlight into attic, lined with mirrors that reflect light to absorbers. Reflectors are inner surfaces of a pyramid lying on its side with window at its base and absorber plates in a cross-sectional plane near its apex.
Source record↗
A pentahedral pyramidal concentrator design for space solar array
A truncated pentahedral pyramidal solar concentrator configuration has been selected as the most favorable candidate capable of providing low-cost multi-hundred-kilowatts (kW) solar array in low earth orbit. This concentrator has the advantages of: commonality for applications using either gallium arsenide (GaAs) or silicon (Si) solar cells, cost effectiveness, structural simplicity, and compatibility with the Shuttle. Results of concentrator optical ray trace, benefit of radiator, deployment mechanism, array power, and cost analysis are discussed.
Hsu, L.↗
A GTD study of pyramidal horns for offset reflector antenna applications
An efficient computational method is demonstrated for determining the far-field patterns of reflectors illuminated by pyramidal horns. A uniform geometrical theory of diffraction (GTD) formulation is used to determine the near- and far-fields of the horn. The far-field patterns of the offset reflector are constructed using the physical optics (PO) formulation in conjunction with the Jacobi-Bessel expansion method. Many representative results are shown for the far-field patterns of the reflector. In particular, the concept of the optimum phase center for the best location of a horn illuminating a reflector is carefully studied and some useful observations are made.
Huang, J.↗
Study of the lithology, petrology and rock chemistry for the Pyramid Mountains, New Mexico
Rock and soil samples were collected at 24 sites within the Pyramid Mountains of southwestern New Mexico. The site locations are specified as 10-acre plots within the Section, Township, and Range land survey system. Hand specimen are described. The specimen were analyzed by X-ray fluorescence. The technique is designed to obtain good analysis for silica. The other elements are run so that matrix factor logic can be used to adjust the silica intensities, and to compensate for the element interaction.
Grant, S. K.↗
PIPS: A Procedure for Interactive Pyramid Segmentation
The Procedure for Interactive Pyramid Segementation was designed to identify regions of spatially connected and spectrally homogeneous pixels in multispectral image data, and to allow these regions to be interactively manipulated without the use of processing parameters. The objective is to provide the user with the capability to easily extract and identify regions corresponding to target objects of interest. The approach is to segment a multispectral image into a set of regions and to allow the analyst to interactively refine the segmentation by direct manipulation. The user can elect to: interactively display maps of the spatial distribution of regions for any designated image subset; display the statistics of a given region; and label, merge, or split regions.
Wharton, S. W.↗
Pyramidal Image-Processing Code For Hexagonal Grid
Algorithm based on processing of information on intensities of picture elements arranged in regular hexagonal grid. Called "image pyramid" because image information at each processing level arranged in hexagonal grid having one-seventh number of picture elements of next lower processing level, each picture element derived from hexagonal set of seven nearest-neighbor picture elements in next lower level. At lowest level, fine-resolution of elements of original image. Designed to have some properties of image-coding scheme of primate visual cortex.
Watson, Andrew B.↗
Using image pyramids for the visualization of large terrain data sets
Viewing terrain data from various remote sensors in three dimensions has proven to be a valuable tool for scientists in understanding a variety of problems. A technique is presented for using image pyramids in such visualization of large terrain data sets, providing up to two orders of magnitude performance enhancement over simpler techniques, while at the same time eliminating false high-frequency information, which causes animations to sparkle.
Stanfill, Daniel F., IV↗
Modified Mean-Pyramid Coding Scheme
Modified mean-pyramid coding scheme requires transmission of slightly fewer data. Data-expansion factor reduced from 1/3 to 1/12. Schemes for progressive transmission of image data transmitted in sequence of frames in such way coarse version of image reconstructed after receipt of first frame and increasingly refined version of image reconstructed after receipt of each subsequent frame.
Cheung, Kar-Ming↗
Low-Speed Static Stability and Control Characteristics of a Model of a Right Triangular Pyramid Reentry Configuration
An investigation of the low-speed static stability and control characteristics of a model of a right triangular pyramid reentry configuration has been made in the Langley free-flight tunnel. The investigation showed that the model had generally satisfactory longitudinal and lateral static stability characteristics. The maximum lift-drag ratio was increased from about 3 to 5 by boattailing the base of the model.
Paulson, John W.↗