9,448 research outputs found
Use of steepest descent and various approximations for efficient computation of minimum noise aircraft landing trajectories
The following areas related to landing trajectory optimization research were discussed: (1) programming and modifying the steepest descent optimization procedure, (2) successfully iterating toward the optimum for a four-mile trajectory, (3) beginning optimization runs for a twenty-mile trajectory, and (4) adapt wind tunnel data for computer usage. Other related areas were discussed in detail in the two previous annual reports
Optimization and sensitivity studies of flight-path trajectories
The optimization of landing trajectories of the Boeing 737 is presented. The primary factor considered was the noise delivered to the population residing near an air terminal but passenger comfort, fuel consumption and time elapsed during the maneuver were also considered. A digital simulation of the aircraft, a noise model and a passenger comfort model, was completed. The digital simulation was made more efficient time-wise. A population model for an urban area was developed and the noise model was integrated into the population model. A steepest descent optimization algorithm was programmed. Some constant glide slope trajectories into an urban Airport were simulated and evaluated with respect to the performance index, and their ground track plotted
Ion composition in a noctilucent cloud
Ion composition at mesospheric altitudes was measured and compared between high and mid-latitude sites under summer daytime conditions. Rocket-borne measurements were made with pumped quadrupole ion mass spectrometers. The mid-latitude data were obtained at Wallops Island, Virginia on June 30, 1973, at 1510 LMT. Large quantities of hydronium cluster ions were observed through 109+, with maximum concentrations at 55+ and 73+. Also, cluster ions of nitric oxide were observed through 84+. The high latitude launch occurred at Kiruna, Sweden on August 2, 1973, at 0700 LMT following visual sighting of a noctilucent cloud on the prior evening. The data near mesopause shows cluster ions, but also a preponderance of heavy ions between 90 and 145 AMU, with groupings 18 AMU apart but unrelated to the more typical cluster ions. One possible set of consistent identifications leads to iron and iron oxide hydrates. These results may suggest the presence of metallic particulates and ions which form hydrated clusters ions
Using HCMM Thermal Data to Improve Classification of MSS Data
Spectral overlap between urban and rural land use/land cover categories can lead to unacceptable map accuracy levels in the classification of LANDSAT multispectral scanner (MSS) data. The four MSS bands used alone are not always adequate to distinguish among various land uses and cover types having similar spectral responses. The use of thermal data from the Heat Capacity Mapping Mission (HCMM) satellite as a means of improving MSS land cover classification accuracies for urban versus rural categories was investigated. The approaches used to integrate the HCMM data are described
Monitoring strip mining and reclamation with LANDSAT data in Belmont County, Ohio
The utility of LANDSAT digital data for mapping and monitoring surface mines in Belmont County, Ohio was investigated. Two data sets from 1976 and 1979 were processed to classify level 1 land covers and three strip mine categories in order to examine change over time and assess reclamation efforts. The two classifications were compared with aerial photographs. Results of the accuracy assessment show that both classifications are approximately 86 per cent correct, and that surface mine change detection (date-to-date comparison) is facilitated by the digital format of LANDSAT data
Accurate, rapid, temperature and liquid-level sensor for cryogenic tanks
Thermopiles measure ullage gas temperatures to within plus or minus 1.65 deg K between 20 and 300 deg K, and also serve as point liquid-level sensors. Thermopile technique measures smaller temperature differences by keeping the reference junctions inside the tank and near the temperature range of the measuring junction
An Ounce of Prevention
In conclusion, we have found that an educational and behavioral approach has been most effective in correcting maladaptive behavior in children, and complete success is only limited by our own creativity. We cannot advocate behavior modification for all children because neither we nor our children should adapt to an ineffective educational system. Improvement in programming in both academic and social skills must be of primary emphasis in prevention. We must concentrate our best minds and personnel in the preschool and primary school years. As the child learns to accept the consequences of his behavior, the necessary social skills to meet his needs, and the basic information for decision making, he will be able to approach adulthood with reasonable assurance of success
Quantifying the Structure of Misfolded Proteins Using Graph Theory
The structure of a protein molecule is highly correlated to its function. Some diseases such as cystic fibrosis are the result of a change in the structure of a protein so that this change interferes or inhibits its function. Often these changes in structure are caused by a misfolding of the protein molecule. To assist computational biologists, there is a database of proteins together with their misfolded versions, called decoys, that can be used to test the accuracy of protein structure prediction algorithms. In our work we use a nested graph model to quantify a selected set of proteins that have two single misfold decoys. The graph theoretic model used is a three tiered nested graph. Measures based on the vertex weights are calculated and we compare the quantification of the proteins with their decoys. Our method is able to separate the misfolded proteins from the correctly folded proteins
PH14-8Mo stainless steel honey comb core shear strength at elevated temperatures, 1 July 1968 - 1 July 1969
PH-8Mo stainless steel honeycomb sandwich cor
Roll diffusion bonding of titanium alloy panels
Roll diffusion bonding technique is used for fabricating T-stiffened panel assemblies from titanium alloy. The single unit fabrication exhibits excellent strength characteristics under tensile and compressive loads. This program is applied to structures in which weight/strength ratio and integral construction are important considerations
- …