408 research outputs found
Microwave radiative transfer studies of precipitation
Since the deployment of the DMSP SSM/I microwave imagers in 1987, increased utilization of passive microwave radiometry throughout the 10 - 100 GHz spectrum has occurred for measurement of atmospheric constituents and terrestrial surfaces. Our efforts have focused on observations and analysis of the microwave radiative transfer behavior of precipitating clouds. We have focused particular attention on combining both aircraft and SSM/I radiometer imagery with ground-based multiparameter radar observations. As part of this and the past NASA contract, we have developed a multi-stream, polarized radiative transfer model which incorporates scattering. The model has the capability to be initialized with cloud model output or multiparameter radar products. This model provides the necessary 'link' between the passive microwave radiometer and active microwave radar observations. This unique arrangement has allowed the brightness temperatures (TB) to be compared against quantities such as rainfall, liquid/ice water paths, and the vertical structure of the cloud. Quantification of the amounts of ice and water in precipitating clouds is required for understanding of the global energy balance
Winter School on Impact of Climate Change on Indian Marine Fisheries Lecture Notes - Part 1, CMFRI, Cochin held on 18.1.2008 - 7.2.2008
The man-made problem of climate change is emerging as the biggest test for humankind. The
greenhouse gas emission is increasing rapidly, and if unchecked, is likely to reach unprecedented and
irreversible levels in another three to four decades. Every individual will have to experience the hardship of
climate change in the near future. This challenge calls for preparedness and action at every level
Surfacing activity and food utllization in a tropical air-breathing fish exposed to different temperatures
In tropical countries like India, \vhere availability of
freshwater is limited , air-breathing fishes may be chosen
for aquaculture, as they thrive in shallow waters deficient
in oxygen. However, the advantageous air-breathing
habit of these fishes and the consequent need to surface
more or less at regular intervals may impose a considerable
drain of energy, which otherwise could have been
channelled into fish productio
Erythrocyte count and haemoglobin concentration of some tropical fishes
In all three species studied, values obtained for
blood properties such as erythrocyte counts haemoglobin
concentration were the highest for males,
intermediate for females and least for juveniles.
The reason for the sex-dependent changes in the
blood properties is not at present clear
Effects of feeding and starvation on growth and swimming activity in an obligatory air-breathing fish
There exists an enormous body of literature on metabolism of fishes as studied by oxygen consumption. Since
standard metabolism relates to 'maintenance energy cost'
of nonfeeding, nondigesting, nongrowing, nonactive fish,
Winberg (1956) rightly appealed for more studies on active
metabolism. Studies on -active metabolism required
exercising apparatus and techniques, such as grids or
electrified fields, to ensure a high sustained level of activit
Effects of food quality on swimming activity and food utilization in the air-breathing fish Ophiocephalus striatus
In cylindrical aquaria, liver fed O. striatus increased surfacing from 1104 times at 2.5 cm depth
to 1738 times/day at 40 cm depth. Due to the sustained surfacing. O. striatus "hung" to the surface
20 times for 1 h/day in the former and 27 times for 3.2 h/day in the latter. Feeding increased from
24 to 40 mg/g.day, assimilation 24 to 34 mg/gтАвday and metabolism 0.5 to.1.1 ml O2 uptake/gтАвh
in these groups
Food utilization in the fish Tilapia mossambica fed on plant and animal foods
Only a few publications are available concerning food utilization in herbivorous
fishes (see PANDIAN, 1975). MENZEL (1959) found that angelfish Holacanthus bermudi?
nsis, fed on epizoan-free filamentous algae, failed to deposit protein ; he concluded
that, though the utilized algae were sufficient to meet the metabolic energy requirements,
the animal matter ingested intentionally or accidentally by the angelfish was
essential to insure "true growth" (GERKING, 1952)
Food intake, conversion and swimming activity in the air-breathing catfish Heteropneustes fossilis
Pandian & Vivekanandan (1976) and Vivekanandan
([976), who considered feeding rate and conversion efficiency
estimates as parameters for assessing metabolic
rates and efficiencies. observed that the obligatory airbreathing
fish Opiliocepha/us slriatus, reared in aquaria
containing different depths of water, swam longer or shorter
distance to exhange atmospheric air; such a design of
experiment permitted them to measure food intake.
growth and sustained active metabolism on a long term
basis
Plausibility Verification for 3D Object Detectors Using Energy-Based Optimization
Environmental perception obtained via object detectors have no predictable safety layer encoded into their model schema, which creates the question of trustworthiness about the system\u27s prediction. As can be seen from recent adversarial attacks, most of the current object detection networks are vulnerable to input tampering, which in the real world could compromise the safety of autonomous vehicles. The problem would be amplified even more when uncertainty errors could not propagate into the submodules, if these are not a part of the end-to-end system design. To address these concerns, a parallel module which verifies the predictions of the object proposals coming out of Deep Neural Networks are required. This work aims to verify 3D object proposals from MonoRUn model by proposing a plausibility framework that leverages cross sensor streams to reduce false positives. The verification metric being proposed uses prior knowledge in the form of four different energy functions, each utilizing a certain prior to output an energy value leading to a plausibility justification for the hypothesis under consideration. We also employ a novel two-step schema to improve the optimization of the composite energy function representing the energy model
Comparisons of precipitation measurements by the Advanced Microwave Precipitation Radiometer and multiparameter radar
Includes bibliographical references.Multiparameter microwave radar measurements are based on dual-polarization and dual-frequency techniques and are well suited for microphysical inferences of complex precipitating clouds, since they depend upon the size, shape, composition, and orientation of a collection of discrete random scatterers. Passive microwave radiometer observations represent path integrated scattering and absorption phenomena of the same scatterers. The response of the upwelling brightness temperatures TB to the precipitation structure depends on the vertical distribution of the various hydrometeors and gases, and the surface features. As a result, combinations of both active and passive techniques contain great potential to markedly improve the longstanding issue of precipitation measurement from space. The NASA airborne Advanced Microwave Precipitation Radiometer (AMPR) and the National Center for Atmospheric Research (NCAR) CP-2 multiparameter radar were jointly operated during the 1991 Convection and Precipitation/Electrification experiment (CaPE) in central Florida. The AMPR is a four channel, high resolution, across-track scanning total power radiometer system using the identical multifrequency feedhorn as the widely utilized Special Sensor Microwave/Imager (SSM/I) satellite system. Surface and precipitation features are separable based on the TB behavior as a function of the AMPR channels. The radar observations are presented in a remapped format suitable for comparison with the multifrequency AMPR imagery. Striking resemblances are noted between the AMPR imagery and the radar reflectivity at successive heights, while vertical profiles of the CP-2 products along the nadir trace suggest a storm structure consistent with the viewed AMPR TB. Directly over the storm cores, the difference between the 37 and 85 GHz TB was noted to approach (and in some cases fall below) zero. Microwave radiative transfer computations show that this is theoretically possible for hail regions suspended aloft in the core of strong convective storms.This work was supported by the NASA Earth Science and Applications Division under Grant NAG8-890. The National Center for Atmospheric Research is sponsored by the National Science Foundation
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