87,693 research outputs found
MISR stereoscopic image matchers: techniques and results
No full textThe Multi-angle Imaging SpectroRadiometer (MISR) instrument, launched in December 1999 on the NASA EOS Terra satellite, produces images in the red band at 275-m resolution, over a swath width of 360 km, for the nine camera angles 70.5/spl deg/, 60/spl deg/, 45.6/spl deg/, and 26.1/spl deg/ forward, nadir, and 26.1/spl deg/, 45.6/spl deg/, 60/spl deg/, and 70.5/spl deg/ aft. A set of accurate and fast algorithms was developed for automated stereo matching of cloud features to obtain cloud-top height and motion over the nominal six-year lifetime of the mission. Accuracy and speed requirements necessitated the use of a combination of area-based and feature-based stereo-matchers with only pixel-level acuity. Feature-based techniques are used for cloud motion retrieval with the off-nadir MISR camera views, and the motion is then used to provide a correction to the disparities used to measure cloud-top heights which are derived from the innermost three cameras. Intercomparison with a previously developed "superstereo" matcher shows that the results are very comparable in accuracy with much greater coverage and at ten times the speed. Intercomparison of feature-based and area-based techniques shows that the feature-based techniques are comparable in accuracy at a factor of eight times the speed. An assessment of the accuracy of the area-based matcher for cloud-free scenes demonstrates the accuracy and completeness of the stereo-matcher. This trade-off has resulted in the loss of a reliable quality metric to predict accuracy and a slightly high blunder rate. Examples are shown of the application of the MISR stereo-matchers on several difficult scenes which demonstrate the efficacy of the matching approach
UMP terima kunjungan Presiden MISR University for Science & Technology
Get PDFSetelah menandatangani memorandum persefahaman (MoU) antara
Misr University for Science & Technology (MUST) dan Universiti Malaysia Pahang (UMP), MUST mengorak langkah maju kehadapan dalam hubungan antara kedua-dua institusi pengajian tinggi dengan mengadakan lawatan rasmi oleh Presiden MUST, Profesor Dr. Mohamed Rafaat Mahmoud ke universiti ini pada 26 hingga 28 April 2009 baru-baru ini
Measuring industry-science links through inventor-author relations: A profiling method
Get PDFIn this pilot study we examine the performance of text-based profiling in recovering a set of validated inventor-author links. In a first step we match patents and publications solely based on their similarity in content. Next, we compare inventor and author names on the highest ranked matches for the occurrence of name matches. Finally, we compare these candidate matches with the names listed in a validated set of inventor-author names. Our text-based profile methodology performs significantly better than a random matching of patents and publications, suggesting that text-based profiling is a valuable complementary tool to the name searches used in previous studies.innovation; industry-science links; text-based profiling;
An optimization approach for aerosol retrievals using simulated MISR radiances
No full textCurrently, many satellite-based aerosol retrievals make use of lookup tables (LUTs) containing precomputed solutions to the radiative transfer (RT) equation. The benefit of this strategy is the avoidance of expensive runtime calculations, but its main drawback is that the LUTs discretize what is inherently a continuous, multivariate solution space. The operational retrieval algorithm for the Multi-angle Imaging SpectroRadiometer (MISR), for example, compares the observations to a set of 74 aerosol mixtures, each composed of particle models having prescribed optical properties and size distributions. In a recent “blind” study comparing the performance of several satellite retrieval algorithms on simulated data over a black surface, the MISR algorithm performed reasonably well in recovering the “true” spectral aerosol optical depths (AODs), but because the correct aerosol model was not contained within the MISR LUT, the retrieved AODs were biased low by ~ 14%. This motivated an investigation of whether an optimization approach, in which the aerosols are modeled by a set of continuously variable parameters recovered using nonlinear least-squares, could improve the results. In this paper, we demonstrate that such an approach using Levenberg–Marquardt optimization yields superior accuracy. Advances in computer speed, development of more efficient RT codes, and algorithm innovations will be necessary for this approach to satisfy the demands of a global, production-level satellite aerosol retrieval process, especially when used in conjunction with future instruments having enhanced sensitivity to diverse aerosol properties.We are grateful to several JPL colleagues for their assistance: Mike Smyth, for refactoring the SOS RT code; Seungwon Lee for help with the optimizations; and Robert West for valuable advice. We thank Yoav Schechner of the Technion Israel Institute of Technology for suggesting the 2-step approach. This research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration (NASA).https://www.sciencedirect.com/science/article/pii/S016980951100172
MISR Radiance Anomalies Induced by Stratospheric Volcanic Aerosols
No full textThe 16-year MISR monthly radiances are analyzed in this study, showing significant enhancements of anisotropic scattering at high latitudes after several major volcanic eruptions with injection heights greater than 14 km. The anomaly of deseasonalized radiance anisotropy between MISR’s DF and DA views (70.5° forward and aft) is largest in the blue band with amplitudes amounting to 5–15% of the mean radiance. The anomalous radiance anisotropy is a manifestation of the stronger forward scattering of reflected sunlight due to the direct and indirect effects of stratospheric volcanic aerosols (SVAs). The perturbations of MISR radiance anisotropy from the Kasatochi (August 2008), Sarychev (June 2009), Nabro (June 2011) and Calbuco (April 2015) eruptions are consistent with the poleward transported SVAs observed by CALIOP and OMPS-LP. In a particular scene over the Arctic Ocean, the stratospheric aerosol mid-visible optical depth can reach as high as 0.2–0.5. The enhanced global forward scattering by SVAs has important implications for the shortwave radiation budget.This research was funded by NASA Terra/MISR and Aura Science Teamshttps://www.mdpi.com/2072-4292/10/12/187
Research fronts in library and information science in Spain
No full textPublications and author cocitations in library and information science in Spain during the period from 1985 to 1994 were analyzed as a measure of the structure, specificity and composition of research fronts in this country. A cocitation matrix developed from an ad hoc database was subjected to cluster analysis, multidimensional scaling and principal components analysis, The resulting cocitation maps identified specific areas of r~search and their knowledge bases. We inferred the degree of consolidation of the discipline of library and information science, and of the subdisciplines informetrics, librarianship and university affiliation, from the research activities revealed. In this respect, the conclusions from the study show the existence of several research fronts in Spanish literature the contents of which are in most cases difficult to compare with those in other countries. A lesser degree of maturity of research in this field is shown
An analysis of the Concept of Freedom and its Implications for Educational Theory and Practice in Egypt, 1805-2000
Get PDFThe current study attempts to analyse the learners' right to freedom in education in order to determine the nature and content of their education. This analysis will be in relation to the philosophy of education in Egypt to improve the efficiency of the educational system. In this sense the aims of the study can be determined as follows: first to propose a theoretical framework of freedom in education in relation to its meaning, conditions, restrictions and
value, secondly, to develop this theoretical framework of education based on freedom so that it suits Egyptian society, can improve the efficiency of the educational system through the idea of freedom, and thirdly, to identify the difficulties and challenges that might
confront the claim to freedom in education in Egypt.
To achieve these aims the study contains seven chapters, an introduction, a conclusion and appendix that are necessary to achieve its aims and answer its questions. The introduction discusses the general outline of the study and the major issues, questions, aims, methodology and plan of the study. The main aim of chapter one is to analyse the concept of freedom in western and Islamic thought to build a theoretical framework of the meaning of freedom, its conditions and value, which is necessary and important to construct a theoretical framework of the meaning, conditions and value of freedom in education for
learners at school level. Chapter two aims to construct a theoretical framework of freedom in education that will depend on the analysis of the concept of freedom made in chapter one. This analysis will deal with the implications of freedom in education with respect to its conditions, restrictions and value in education. Through this analysis, chapter two aims also to analyse and examine the learners' rights to be free regarding their education. To have a
complete theoretical framework of freedom in education, chapter three discusses other implications with respect to restrictions which might limit learners' freedom by being
subject to state authority.
Chapter four investigates and analyses freedom in educational theory and practice in the history of Egypt from 1805 to 1991, whereas chapter five focuses on the period from 1992 to 2000. Following the analysis of the concept of freedom and its implications in education that will be made in the first five chapters, it would be sensible to construct a framework of educational theory based on freedom that, on one hand, should suite the Egyptian context in chapter six, on the other hand, that guarantees a range of freedom that allows learners and
society derive benefit from its value in education. Having proposed a framework of a theory of education based on freedom that suits the Egyptian context to improve the
efficiency of its educational system chapter seven will discover and examine the conditions and difficulties which need to be considered for the successful implementation of freedom in education. Also, the study will attempt to give some suggestions that might help to reduce the gap between the educational situation, its circumstances and the conditions that must be satisfied for the successful implementation of freedom in education
Colorado State University radiation instrumentation and data reduction procedures for the Convail 990 during summer MONEX
Get PDFApril, 1980.Describes the basic system design and the radiative instrumentation maintained by Colorado State University on board the Convail 990 jet aircraft during the Summer Monsoon Experiment (MONEX). Discusses calibration procedures and gives the derived constraints used to convert instrument output to engineering units. Also discusses specific problems encountered during data reduction and the methods used to overcome them.Sponsored by a grant by the Eppley Laboratory, Inc.Sponsored by the National Science Foundation ATM 78-12631
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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Building capacity for societally engaged climate science by transforming science training
No full textA major barrier to achieving wide-spread progress on planning for impacts from climate change is the lack of trained scientists skilled at conducting societally-relevant research. Overcoming this barrier requires us to transform the way we train scientists so they are equipped to work with a range of different societal partners and institutions to produce the science needed to address climate change and society’s other pressing environmental challenges. As researchers at climate research organizations that work directly with decision-makers and stakeholders to produce decision-relevant science, we are entrenched in advancing actionable climate science. Based on our experience preparing scientists for similar careers, we offer a perspective on a path for the academy to better develop, train and support scientists to conduct societally relevant research. We emphasize the need for science training that builds collaborative science skills at different career stages to develop a strong community of practice around actionable climate science. We offer insights from our training and capacity-building programs to demonstrate this transformation, and point to strategies that can be adopted at other universities to grow the capacity of scientists to support society in achieving rapid progress on climate action. © 2020 The Author(s). Published by IOP Publishing LtdOpen access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
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