2,894 research outputs found
Modified Hopfield Neural Network Classification Algorithm For Satellite Images
Air adalah bahan yang penting bagi kehidupan mahkluk di atas muka bumi
ini. Aktiviti manusia dan pengaruh alam semula jadi memberi kesan terhadap
kualiti air, dan ia dianggap satu daripada masalah terbesar yang membelenggui
kehidupan.
Water is an essential material for living creatures. Human activities and natural
influences have an effecting on water quality, and this is considered one of the largest
problems facing living forms
Thin Film Charged Particle Trackers
Silicon tracking detectors have grown to cover larger surface areas up to
hundreds of square meters, and are even taking over other sub-detectors, such
as calorimeters. However, further improvements in tracking detector performance
are more likely to arise from the ability to make a low mass detector comprised
of a high ratio of active sensor to dead materials, where dead materials
include electrical services, cooling, mechanical supports, etc. In addition,
the cost and time to build these detectors is currently large. Therefore,
advancements in the fundamental technology of tracking detectors may need to
look at a more transformative approach that enables extremely large area
coverage with minimal dead material and is easier and faster to build. The
advancement of thin film fabrication techniques has the potential to
revolutionize the next-to-next generation of particle detector experiments.
Some thin film deposition techniques have already been developed and widely
used in the industry to make LED screens for TV's and monitors. If large area
thin film detectors on the order of several square meters can be fabricated
with similar performance as current silicon technologies, they could be used in
future particle physics experiments. This paper aims to review the key
fundamental performance criteria of existing silicon detectors and past
research to use thin films and other semi-conductor materials as particle
detectors in order to explore the important considerations and challenges to
pursue thin film detectors.Comment: 32 pages, 15 figure
Estimating the concentration of physico chemical parameters in hydroelectric power plant reservoir
The United Nations Educational, Scientific and Cultural Organization (UNESCO) defines
the amazon region and adjacent areas, such as the Pantanal, as world heritage territories, since
they possess unique flora and fauna and great biodiversity. Unfortunately, these regions have
increasingly been suffering from anthropogenic impacts. One of the main anthropogenic impacts
in the last decades has been the construction of hydroelectric power plants.
As a result, dramatic altering of these ecosystems has been observed, including changes in
water levels, decreased oxygenation and loss of downstream organic matter, with consequent
intense land use and population influxes after the filling and operation of these reservoirs. This,
in turn, leads to extreme loss of biodiversity in these areas, due to the large-scale deforestation.
The fishing industry in place before construction of dams and reservoirs, for example, has become
much more intense, attracting large populations in search of work, employment and income.
Environmental monitoring is fundamental for reservoir management, and several studies
around the world have been performed in order to evaluate the water quality of these ecosystems.
The Brazilian Amazon, in particular, goes through well defined annual hydrological cycles, which
are very importante since their study aids in monitoring anthropogenic environmental impacts
and can lead to policy and decision making with regard to environmental management of this
area. The water quality of amazon reservoirs is greatly influenced by this defined hydrological
cycle, which, in turn, causes variations of microbiological, physical and chemical characteristics.
Eutrophication, one of the main processes leading to water deterioration in lentic environments,
is mostly caused by anthropogenic activities, such as the releases of industrial and domestic
effluents into water bodies.
Physico-chemical water parameters typically related to eutrophication are, among others,
chlorophyll-a levels, transparency and total suspended solids, which can, thus, be used to assess
the eutrophic state of water bodies.
Usually, these parameters must be investigated by going out to the field and manually
measuring water transparency with the use of a Secchi disk, and taking water samples to the
laboratory in order to obtain chlorophyll-a and total suspended solid concentrations. These
processes are time- consuming and require trained personnel. However, we have proposed other
techniques to environmental monitoring studies which do not require fieldwork, such as remote
sensing and computational intelligence.
Simulations in different reservoirs were performed to determine a relationship between these
physico-chemical parameters and the spectral response. Based on the in situ measurements,
empirical models were established to relate the reflectance of the reservoir measured by the
satellites. The images were calibrated and corrected atmospherically.
Statistical analysis using error estimation was used to evaluate the most accurate methodology.
The Neural Networks were trained by hydrological cycle, and were useful to estimate the physicalchemical
parameters of the water from the reflectance of visible bands and NIR of satellite images,
with better results for the period with few clouds in the regions analyzed.
The present study shows the application of wavelet neural network to estimate water quality
parameters using concentration of the water samples collected in the Amazon reservoir and Cefni
reservoir, UK. Sattelite imagens from Landsats and Sentinel-2 were used to train the ANN by
hydrological cycle.
The trained ANNs demonstrated good results between observed and estimated after Atmospheric
corrections in satellites images. The ANNs showed in the results are useful to estimate
these concentrations using remote sensing and wavelet transform for image processing.
Therefore, the techniques proposed and applied in the present study are noteworthy since
they can aid in evaluating important physico-chemical parameters, which, in turn, allows for identification of possible anthropogenic impacts, being relevant in environmental management
and policy decision-making processes.
The tests results showed that the predicted values have good accurate. Improving efficiency
to monitor water quality parameters and confirm the reliability and accuracy of the approaches
proposed for monitoring water reservoirs.
This thesis contributes to the evaluation of the accuracy of different methods in the estimation
of physical-chemical parameters, from satellite images and artificial neural networks. For future
work, the accuracy of the results can be improved by adding more satellite images and testing
new neural networks with applications in new water reservoirs
Determine utility of ERTS-1 to detect and monitor area strip mining and reclamation
The author has identified the following significant results. Computer techniques were applied to process ERTS tapes acquired over coal mining operations in southeastern Ohio on 21 August 1972 and 3 September 1973. ERTS products obtained included geometrically correct map overlays showing stripped earth, partially reclaimed earth, water, and natural vegetation. Computer-generated tables listing the area covered by each land-water category in square kilometers and acres were produced. By comparing these mapping products, the study demonstrates the capability of ERTS to monitor changes in the extent of stripping, success of reclamation, and the secondary effects of mining on the environment
NASA SBIR abstracts of 1991 phase 1 projects
The objectives of 301 projects placed under contract by the Small Business Innovation Research (SBIR) program of the National Aeronautics and Space Administration (NASA) are described. These projects were selected competitively from among proposals submitted to NASA in response to the 1991 SBIR Program Solicitation. The basic document consists of edited, non-proprietary abstracts of the winning proposals submitted by small businesses. The abstracts are presented under the 15 technical topics within which Phase 1 proposals were solicited. Each project was assigned a sequential identifying number from 001 to 301, in order of its appearance in the body of the report. Appendixes to provide additional information about the SBIR program and permit cross-reference of the 1991 Phase 1 projects by company name, location by state, principal investigator, NASA Field Center responsible for management of each project, and NASA contract number are included
Third ERTS Symposium: Abstracts
Abstracts are provided for the 112 papers presented at the Earth Resources Program Symposium held at Washington, D.C., 10-14 December, 1973
National Aeronautics and Space Administration fundamental research program. Information utilization and evaluation, appendices
Important points presented and recommendations made at an information and decision processes workshop held in Asilomar, California; at a data and information performance workshop held in Houston, Texas; and at a data base use and management workshop held near San Jose, California are summarized. Issues raised at a special session of the Soil Conservation Society of America's remote sensing for resource management conference in Kansas City, Missouri are also highlighted. The goals, status and activities of the NASA program definition study of basic research requirements, the necessity of making the computer science community aware of user needs with respect to information related to renewable resources, performance parameters and criteria for judging federal information systems, and the requirements and characteristics of scientific data bases are among the topics reported
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