7,351 research outputs found
LANDSAT Digital Data Base Preparation for the Pennsylvania Defoliation Application Pilot Test
A LANDSAT digital mosaic data base for the State of Pennsylvania was prepared for use in the development of an automated system to annually estimate the extent and severity of Gypsy Moth defoliation of hardward forests. The techniques for detecting the defoliation and development of a geographic information system (GIS) to assess damage is being developed jointly by NASA/Goddard Space Flight Center and Pennsylvania State University using the JPL prepared mosaic base. The JPL processing involved the use of ground control points from the Master Data Processor for planimetric control, resampling of the LANDSAT data to 57 x 57 meter pixels, realignment to north, and reprojection to the Universal Transverse Mercator (UTM) projection in UTM zones 17 and 18. The completed mosaic for each UTM zone was subdivided into 1 degree of latitude by 2 degrees of longitude quadrangles for easy data handling. Consideration is given to the issues of mapping standards, sensor and spacecraft platform characteristics, and their implication to geographic information systems operation. Methods for obtaining measures of accuracy for LANDSAT mosaics are reviewed
Triaxial digital fluxgate magnetometer for NASA applications explorer mission: Results of tests of critical elements
Tests performed to prove the critical elements of the triaxial digital fluxgate magnetometer design were described. A method for improving the linearity of the analog to digital converter portion of the instrument was studied in detail. A sawtooth waveform was added to the signal being measured before the A/D conversion, and averaging the digital readings over one cycle of the sawtooth. It was intended to reduce bit error nonlinearities present in the A/D converter which could be expected to be as much as 16 gamma if not reduced. No such nonlinearities were detected in the output of the instrument which included the feature designed to reduce these nonlinearities. However, a small scale nonlinearity of plus or minus 2 gamma with a 64 gamma repetition rate was observed in the unit tested. A design improvement intended to eliminate this small scale nonlinearity was examined
The host galaxies of luminous radio-quiet quasars
We present the results of a deep K-band imaging study which reveals the host
galaxies around a sample of luminous radio-quiet quasars. The K-band images,
obtained at UKIRT, are of sufficient quality to allow accurate modelling of the
underlying host galaxy. Initially, the basic structure of the hosts is revealed
using a modified Clean deconvolution routine optimised for this analysis. 2 of
the 14 quasars are shown to have host galaxies with violently disturbed
morphologies which cannot be modelled by smooth elliptical profiles. For the
remainder of our sample, 2D models of the host and nuclear component are fitted
to the images using the chi-squared statistic to determine goodness of fit.
Host galaxies are detected around all of the quasars. The reliability of the
modelling is extensively tested, and we find the host luminosity to be well
constrained for 9 quasars. The derived average K-band absolute K-corrected host
galaxy magnitude for these luminous radio-quiet quasars is =-25.15+/-0.04,
slightly more luminous than an L* galaxy. The spread of derived host galaxy
luminosities is small, although the spread of nuclear-to-host ratios is not.
These host luminosities are shown to be comparable to those derived from
samples of quasars of lower total luminosity and we conclude that there is no
correlation between host and nuclear luminosity for these quasars.
Nuclear-to-host ratios break the lower limit previously suggested from studies
of lower nuclear luminosity quasars and Seyfert galaxies. Morphologies are less
certain but, on the scales probed by these images, some hosts appear to be
dominated by spheroids but others appear to have disk-dominated profiles.Comment: 16 pages, 8 figures, revised version to be published in MNRA
NICMOS Observations of Low-Redshift Quasar Host Galaxies
We have obtained Near-Infrared Camera and Multi-Object Spectrometer images of
16 radio quiet quasars observed as part of a project to investigate the
``luminosity/host-mass limit.'' The limit results were presented in McLeod,
Rieke, & Storrie-Lombardi (1999). In this paper, we present the images
themselves, along with 1- and 2-dimensional analyses of the host galaxy
properties. We find that our model-independent 1D technique is reliable for use
on ground-based data at low redshifts; that many radio-quiet quasars live in
deVaucouleurs-law hosts, although some of the techniques used to determine host
type are questionable; that complex structure is found in many of the hosts,
but that there are some hosts that are very smooth and symmetric; and that the
nuclei radiate at ~2-20% of the Eddington rate based on the assumption that all
galaxies have central black holes with a constant mass fraction of 0.6%.
Despite targeting hard-to-resolve hosts, we have failed to find any that imply
super-Eddington accretion rates.Comment: To appear in ApJ, 28 pages including degraded figures. Download the
paper with full-resolutio figures from
http://www.astro.wellesley.edu/kmcleod/mm.p
All Things in Aggregation: Reassessing the Fourth Amendment\u27s Third-Party Doctrine and the Fourth Circuit\u27s Approach to Cell Site Location Information in \u3cem\u3eUnited States v. Graham\u3c/em\u3e
Math Coaching In Metropolitan Detroit
On-going professional development for in-service teachers is critical to efforts to reform schools and increase student achievement. Coaching has been advocated as an approach to meet the conditions of quality professional development, and it has demonstrated a positive impact on student mathematics achievement scores when implemented over multiple years. Ambiguity of title, definition, and role surround coaching, presenting challenges to its execution in schools.
This study proposed a definition of Enacted Math Coaching to help address this ambiguity. As schools throughout Metropolitan Detroit adopt coaching as a component of school reform initiatives, the purpose of this study was to document and describe the professional experience and daily work of mathematics coaches in schools in Metropolitan Detroit. This included an exploration of the qualifications coaches bring to the role and their on-going professional development opportunities, as well as an analysis of their intended and enacted goals and activities. Data was gathered using a questionnaire, interviews, observations, and existing documents.
This study found clarity and consensus on the audience and purpose for math coaching. A review of the activities which coaches valued, and those on which they spent their time, highlighted a disconnect between priorities and implementation. Coaches reported spending only one fourth of their time on coaching activities of any type. Coaches had received training in curriculum materials, analyzing tasks and lessons in terms of the underlying mathematics, and strategies for supporting teachers and students. They sought more development in working with adult learners and strategies for supporting low-achieving students
Resources, Trade, and Debt
The paper studies a two-region economy that has two sectors and three factors of production: oil, capital, and labor. The South exports oil in exchange for industrial goods from the North. There is a net capital inflow to the South. This equals the difference between its export revenues and import costs, and represents the South's indebtedness. This overseas borrowing finances the development of the oil sector: increased borrowing leads to &her oil supplies, to new levels of consumption and a new distribution of income in the South, and to new levels of industrial exports from the North. The paper studies the macro impacts of changes in the values of the debt on both the borrowing and the lending regions
A feasibility study: Forest Fire Advanced System Technology (FFAST)
The National Aeronautics and Space Administration/Jet Propulsion Laboratory and the United States Department of Agriculture Forest Service completed a feasibility study that examined the potential uses of advanced technology in forest fires mapping and detection. The current and future (1990's) information needs in forest fire management were determined through interviews. Analysis shows that integrated information gathering and processing is needed. The emerging technologies that were surveyed and identified as possible candidates for use in an end to end system include ""push broom'' sensor arrays, automatic georeferencing, satellite communication links, near real or real time image processing, and data integration. Matching the user requirements and the technologies yielded a ""strawman'' system configuration. The feasibility study recommends and outlines the implementation of the next phase for this project, a two year, conceptual design phase to define a system that warrants continued development
Waterfowl Harvest Benefits in Northern Aboriginal Communities and Potential Climate Change Impacts
Migratory waterfowl are important to the diets of residents in Canada’s northern communities. Contrary to recreational hunters, indigenous peoples have rights to harvest wildlife for subsistence needs without permits. As a result, migratory waterfowl are an important component of diets of Aboriginal peoples in northern Canada, substituting for expensive beef transported from the south. Wild geese and duck provide many benefits to native people, including improved nutrition and health. In this paper, scaled-down data from global climate models are used in a wildlife model to project potential migratory waterfowl abundance in the Northwest Territories for three future periods up to 2080. The models project potential future harvests of geese and ducks by Aboriginal hunters and the financial and nutritional benefits. It turns out that northern Aboriginal peoples can benefit significantly as a result of climate change that affects migratory waterfowl, but likely at the expense of hunters and recreationists in other regions of North America.subsistence harvests by indigenous peoples; diet and nutrition; climate change
- …