Theory and measure of certain image norms in SAR

The principal properties of synthetic aperture radar SAR imagery of point and distributed objects are summarized. Against this background, the response of a SAR (Synthetic Aperture Radar) to the moving surface of the sea is considered. Certain conclusions are drawn as to the mechanism of interaction between microwaves and the sea surface. Focus and speckle spectral tests may be used on selected SAR imagery for areas of the ocean. The fine structure of the sea imagery is sensitive to processor focus and adjustment. The ocean reflectivity mechanism must include point like scatterers of sufficient radar cross section to dominate the return from certain individual resolution elements. Both specular and diffuse scattering mechanisms are observed together, to varying degree. The effect is sea state dependent. Several experiments are proposed based on imaging theory that could assist in the investigation of reflectivity mechanisms

Noise prediction technology for CTOL aircraft

The application of a new aircraft noise prediction program to CTOL noise prediction is outlined. Noise prediction is based on semiempirical methods for each of the propulsive system noise sources, such as the fan, the combustor, the turbine, and jet mixing, with noise-critical parameter values derived from the thermodynamic cycle of the engine. Comparisons of measured and predicted noise levels for existing CTOL aircraft indicate an acceptable level of accuracy

An alternative multi-mode SAR for RADARSAT

The RADARSAT project was asked by the Canadian government in the spring of 1986 to design for reduced costs and increased radar performance as compared to the well-known baseline design. Both the Project Office and Canadian industry (lead by SPAR Aerospace of Montreal) have undertaken to meet this request, with a proposal to cabinet to be submitted in the fall of 1986. One alternative SAR concept is outlined which is under consideration for a revised RADARSAT configuration. The radar system described uses two frequencies (C&L band) over four possible modes: near range swath; far range swath; wide swath; and high resolution. Good sensitivity, resolution, and coverage are obtained with modest power and data rates. The antenna systems are relatively simple. Indeed, no break-through technological developments are needed. The design allows several mode combinations for simultaneous data collection or performance enhancement. The principal parameters are described. A nominal mean altitude of 700 km is assumed

A solution to the problem of SAR range curvature

When synthetic aperture radar systems are pushed to attain finer resolution at larger ranges than was previously the case for remote sensing purposes, the geometric signal aberration known as range curvature arises. Known techniques for correcting range curvature are exact at only one selected range, thus forcing neighboring ranges to use the same correction as an approximation. A solution to the problem is proposed that is exact at all ranges, thus simplifying and improving the image processing for such systems

Transcriptional regulation of the hepatitis B virus large surface antigen gene

Hepatitis B virus (HBV) is a hepatotropic virus of highly restricted host range and tissue specificity. Although the mechanisms governing this tropism are not fully understood, it is likely that restrictions occur at multiple steps in the viral life cycle. The liver-specific regulation of HBV gene expression suggests that transcription may be an important factor in the hepatotropism of the virus. An analysis of tissue- or cell- line-specific regulation of the HBV promoters may elucidate the role of transcriptional regulation in the hepatotropism of the virus. The major aim of this project was to characterize the transcriptional regulation of the large surface antigen gene of hepatitis B virus. To achieve this, the regions of the HBV genome involved in the regulation of the expression of the large surface antigen gene were identified using a transient transfection system in mammalian cell lines. The transcriptional activities of the four HBV promoters were compared in the human differentiated hepatoma cell lines Hep3B, PLC/PRF/5, HepG2 and Huh7, a human dedifferentiated hepatoma cell line HepG2.1, and the nonhepatoma cell lines HeLa S3 and NIH 3T3. To determine the relative transcriptional activities of the four HBV promoters, reporter gene plasmids were generated such that the expression of the firefly luciferase gene was under the control of each of the HBV promoters in the context of the complete genome. The nucleocapsid promoter and large surface antigen promoter displayed higher relative activities in the differentiated hepatoma cell lines, indicating that these promoters are preferentially active in these cell lines. A series of large surface antigen promoter deletion plasmids were constructed to identify the important regulatory regions of the large surface antigen promoter. The deletion analysis demonstrated that the region responsible for the high relative activity in differentiated hepatoma cell lines is located between -90 and -76 relative to the transcription initiation site (-*■!) located at map position 2809. This sequence element contains the binding site (GTTAATCATTACT) for the liver-enriched transcription factor hepatocyte nuclear factor I, HNF1. A eukaryotic expression vector containing the HNFI cDNA under the control of the mouse metallothionein I promoter was cotransfected with the HBV promoter constructs in Huh7 and HepG2.1 cells, and the relative levels of activity were determined. The Huh7 cell line was used because it is one of the cell lines in which HBV replication and particle production can occur and may represent the tissue culture system closest to the natural environment for the HBV life cycle, the liver cell. The cloned transcription factor HNFI activated transcription from the large surface antigen promoter, but not from any of the other HBV promoters. Cotransfection experiments using the HNFI cDNA expression vector and large surface antigen promoter deletion constructs demonstrated that this transactivation was mediated through the HNFI binding site located between -90 and -76 in the large surface antigen promoter. A series of deletion mutants of the cDNA in the HNFI expression vector was generated to determine the transcriptional activation domain of the HNFI polypeptide. The major domain of the HNFI polypeptide involved in transcriptional activation of the large surface antigen promoter in the human hepatoma cell line HepG2.1 was mapped to a region rich in glutamine and proline residues (9 of 18 residues). To demonstrate directly that the HNFI polypeptide produced by the expression of the HNFI cDNA could bind the large surface antigen promoter HNFI recognition sequence, and to determine whether a protein present in the differentiated hepatoma cell line Huh7 bound the HNFI element, gel mobility shift analysis was performed. This analysis demonstrated that a protein present in nuclear extracts from Huh7 cells formed a specific complex with the HNFI binding site which had similar migration properties to the complex formed between exogenously expressed HNFI and the HNFI recognition sequence. DNase I footprinting analysis demonstrated the binding of a protein present in the differentiated hepatoma cell line Huh7 to the HNFI recognition sequence in the large surface antigen promoter. DNase I footprinting also showed that purified TATA binding protein binds the TATA box element located between -31 and -23 in the large surface antigen promoter. The analysis of synthetic promoter constructs suggested that the HNFI and TATA box elements were the only elements necessary for maximal activity from the large surface antigen promoter, and analysis of clustered point mutations in the large surface antigen minimal promoter region demonstrated that sequences between the HNFI and TATA box elements were not required for the HNF1- dependent activity of the large surface antigen promoter. These studies suggested that the liver-enriched transcription factor HNFI plays a critical role in the cell-line and tissue-specific regulation of the HBV large surface antigen promoter

Predicted airframe noise levels

Calculated values of airframe noise levels corresponding to FAA noise certification conditions for six aircraft are presented. The aircraft are: DC-9-30; Boeing 727-200; A300-B2 Airbus; Lockheed L-1011; DC-10-10; and Boeing 747-200B. The prediction methodology employed is described and discussed

Social gains from female education : a cross-national study

The authors explore the strength of female secondary education relative to, and in combination with, family planning and health programs in reducing fertility and infant mortality. They find that family planning and health programs do influence fertility and mortality, but that the impact of expanding female secondary enrollments appears to be much greater, especially in countries with low female secondary enrollment. Fertility and infant mortality are more elastic with respect to female secondary education than to family planning and health programs. Their simulations suggest the following. Doubling female secondary school enrollment (from 19 to 38 percent) in 1975 would have reduced the total fertility rate in 1985 from 5.3 to 3.9. Doubling the family planning service score (from 25 to 50 percent) in 1982 would have reduced the total fertility rate only from 5.5 to 5.0. Doubling female secondary school enrollment in 1975 from 19 to 38 would have reduced the infant mortality rate from 81 to 38. Halving the ratio of population per physician would have reduced the infant mortality rate only from 85 to 81. Doubling per capita GDP from $650 to$1,300 would have reduced the infant mortality rate only from 98 to 92. Doubling female secondary school enrollment (from 19 to 38) in 1975 would have lowered the number of births by 29 percent of the 1985 number. Doubling family planning services would have reduced it by 3.5 percent. Doubling female secondary school enrollment would have reduced infant deaths by 64 percent. Halving the ratio of population per physician would have reduced it only by 2.5 percent. Doubling per capita GDP has no effect on reducing infant deaths, all other factors being constant. Female education affects desired family size by raising the opportunity cost of a woman's time in economic activities, increasing demand for family planning, and promoting more effective contraceptive use.Health Monitoring&Evaluation,Early Child and Children's Health,Adolescent Health,Agricultural Knowledge&Information Systems,Education and Society

Company Health Dashboard

Company Health Dashboard is a web application that serves as a tool to display information in dynamic grid-like modules. This application displays viewer-friendly information on the televisions around the company office using Raspberry Pi devices. In order to benefit different types of users, the application divides the screen into multiple customizable modules, with each module representing different information. Company employees, for example, can view information about company news, upcoming events, or even what’s on tap for that day. Visitors or clients, on the other hand, can see information about the company while waiting for their meeting. The design of the dashboard is made to the company’s own liking, having a centralized manager page that can customize each module type, name, title, description and background image. The manager has the ability to handle multiple screens, the admin can add multiple screen layouts and assign those layouts to specific televisions around the office. This lets the company have different screens for different floors or rooms depending on their use. This application has a lot of room for customization and will allow employees and visitors to understand the company’s overall status.https://scholarscompass.vcu.edu/capstone/1161/thumbnail.jp

On the determination of near body orbits using mass concentration models

Mathematical model for near-body orbit calculation using mass concentration, perturbation theory, nonlinear equations, geopotentials, and least squares metho

HOW WESTERN HEMISPHERE INTEGRATION AFFECTS THE U.S. ECONOMY IN AN INTERTEMPORAL GLOBAL MODEL

In a global general equilibrium analysis, an FTAA excluding the United States erodes U.S. agricultural trade preferences and export gains achieved under NAFTA. Participation in an FTAA increases U.S. agriculture exports $740 million, with gains in Central American and Caribbean Markets more than offsetting declines in NAFTA, Asia, and Europe.International Relations/Trade,