13,412 research outputs found
Radar shadow detection in SAR images using DEM and projections
Synthetic aperture radar (SAR) images are widely used in target recognition
tasks nowadays. In this letter, we propose an automatic approach for radar
shadow detection and extraction from SAR images utilizing geometric projections
along with the digital elevation model (DEM) which corresponds to the given
geo-referenced SAR image. First, the DEM is rotated into the radar geometry so
that each row would match that of a radar line of sight. Next, we extract the
shadow regions by processing row by row until the image is covered fully. We
test the proposed shadow detection approach on different DEMs and a simulated
1D signals and 2D hills and volleys modeled by various variance based Gaussian
functions. Experimental results indicate the proposed algorithm produces good
results in detecting shadows in SAR images with high resolution.Comment: 10 pages, 6 figure
Land vehicle antennas for satellite mobile communications
The RF performance, size, pointing system, and cost were investigated concepts are: for a mechanically steered 1 x 4 tilted microstrip array, a mechanically steered fixed-beam conformal array, and an electronically steered conformal phased array. Emphasis is on the RF performance of the tilted 1 x 4 antenna array and methods for pointing the various antennas studied to a geosynchronous satellite. An updated version of satellite isolations in a two-satellite system is presented. Cost estimates for the antennas in quantities of 10,000 and 100,000 unites are summarized
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Supporting people with depression and anxiety: a guide for practice nurses
This guide has been devleoped for GP practice nurses following a three year research study called ProCEED (Proactive care and its evaluation for enduring depression), conducted by Dr Marta Buszewicz and a research team at University College London
Agricultural research and poverty reduction:
International agricultural research has contributed enormously to increasing world food supplies to their current state of plenty. Yet poverty remains a major problem and the challenge for agricultural research now lies in developing strategies that more explicitly address the needs of the poor. This paper, based on the study commissioned by the Technical Advisory Committee (TAC) of the CGIAR system, addresses this issue. Based on an analysis of the links between agricultural research and poverty alleviation in different types of countries and rural regions, Peter Hazell and Lawrence Haddad identify six key priorities for a pro-poor agricultural research agenda and discuss strategies for achieving each of these goals with the least trade-off in national agricultural growth. (Excerpted from Forward by Per Pinstrup-Andersen and Emil Javier)agricultural research, poverty, food supply,
Analysis of antioxidant enzyme activity during reproductive stages of barley under drought stress
Drought is especially considered as key stress factor with high potential impact on crop yield. Plants mainly adapt to water deficits by alteration in physiological and biochemical processes. A simulation experiment on the responses of barley (Hordeum Vulgare L.) from heading stage to ripening stage for different soil water levels (full water supply, light water stress, and severe water stress) was conducted to determine the effects on leaf water status, levels of chlorophyll and protein, lipid peroxidation and antioxidant enzymes activity. The results indicated that drought stress relied on drought intensity and developmental stage, with more severe drought stress creating more serious effects on barley. Relative water content (RWC) significantly decreased (P < 0.05) under drought stress in all stages. The content of soluble protein and chlorophyll decreased and membrane lipid peroxidation (measured as malondialdehyde content) increased significantly according to the severity of water stress and reproductive stage. Under water stress, the activities of antioxidant enzymes ascorbate peroxidase (APX), catalase (CAT), guaiacol peroxidase (POX) and superoxide dismutase (SOD) in leaves increased sharply in flowering and milking stages, but then declined towards the lately ripening stage. Furthermore, compared with well watered conditions, changes in the activities of POX and SOD were different between light water stress and severe water stress at flowering and milking stages. However, the increases in the levels of malondialdehyde (MDA) during flowering and milking stages showed that the increased activities of antioxidant enzymes may not be enough to prevent the peroxidation of lipid membranes and to scavenge reactive oxygen species (ROS) under drought stress
Pretextual Fourth Amendment Activity: Another Viewpoint
Pretextual detentions, arrests, and searches pose knotty fourth amendment problems. With an air of plausibility, defense attorneys often accuse police of pretextual use of arrest warrants, search warrants, and various exceptions to the warrant requirement. Specifically, they contend that officers have utilized a particular fourth amendment doctrine to obtain certain evidence even though courts have not assigned as a reason for approving the doctrine the need to discover such evidence
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