1,365 research outputs found
Evaluation of ERBE scanner pointing accuracy based upon a coastline detection algorithm
Measurements from the Earth Radiation Budget Experiment (ERBE) scanning radiometers must be accurately located at the top of the Earth's atmosphere for proper interpretation of derived longwave and shortwave components of the Earth radiation field. The accuracy of the location calculations is affected by the orbit characteristics and attitude control systems of the three spacecraft, ERBS, NOAA-9, and NOAA-10. A technique was developed which makes use of the longwave scanner measurements to detect the thermal gradients at the boundaries of ocean and land masses. By analyzing many such coastline boundaries, estimates of the overall accuracy of the scanner measurement location calculations have been derived for the three satellites. The resulting measurement location errors are found to be smaller than the resolution of the radiometers, and this accuracy is well within the required location knowledge for useful science analysis of the ERBE scanner data
Book Reviews
The legal profession is to be congratulated that men of the great erudition of Dean Wigmore and the editors associated with him are devoting themselves so unselfishly to the heavy labor of presenting in fitting English form the masterpieces of continental legal literature. Though much may be said about the insufficiency of translations as a basis of scholarly work in -any subject, the fact remains that the great bulk of the legal profession, even those of a scholarly habit of mind, have not the linguistic ability necessary to use the original sources of knowledge. On the other hand the need of knowledge of European law is a most insistent one. Our continual round of precedent-grinding, on the basis of the naive political philosophy of the eighteenth century, has long since proved its inadequacy. The profession, or at least the better part of it, is beginning to look for some enlarging and enfranchising ideas, and is ready to welcome them from any source. Though much remains to be done in The detail of working out the history of our own system, we nevertheless have a solid basis of historical knowledge of the common law, thanks to the investigations of our scholars, English and American, in that field: The careful study of cases and the building up of our admirable series of casebooks have made the results of these historical investigations available to the student of our day. The next step forward must be to enlarge the basis of our scholarship by comparative study of other systems in their historical development and to get new points of view as to the meaning and tendency of legal concepts from the legal philosophies of other countries. The translation will give to the average member of the profession and to the ordinary student of law a chance to participate in or at least to keep up with the progress in the comparative and philosophic fields, and will serve the same \u27purpose in this new movement that the casebooks have served in interpreting and passing on the historical knowledge of our own system
Space Station Freedom automation and robotics: An assessment of the potential for increased productivity
This report presents the results of a study performed in support of the Space Station Freedom Advanced Development Program, under the sponsorship of the Space Station Engineering (Code MT), Office of Space Flight. The study consisted of the collection, compilation, and analysis of lessons learned, crew time requirements, and other factors influencing the application of advanced automation and robotics, with emphasis on potential improvements in productivity. The lessons learned data collected were based primarily on Skylab, Spacelab, and other Space Shuttle experiences, consisting principally of interviews with current and former crew members and other NASA personnel with relevant experience. The objectives of this report are to present a summary of this data and its analysis, and to present conclusions regarding promising areas for the application of advanced automation and robotics technology to the Space Station Freedom and the potential benefits in terms of increased productivity. In this study, primary emphasis was placed on advanced automation technology because of its fairly extensive utilization within private industry including the aerospace sector. In contrast, other than the Remote Manipulator System (RMS), there has been relatively limited experience with advanced robotics technology applicable to the Space Station. This report should be used as a guide and is not intended to be used as a substitute for official Astronaut Office crew positions on specific issues
Discrete phase space based on finite fields
The original Wigner function provides a way of representing in phase space
the quantum states of systems with continuous degrees of freedom. Wigner
functions have also been developed for discrete quantum systems, one popular
version being defined on a 2N x 2N discrete phase space for a system with N
orthogonal states. Here we investigate an alternative class of discrete Wigner
functions, in which the field of real numbers that labels the axes of
continuous phase space is replaced by a finite field having N elements. There
exists such a field if and only if N is a power of a prime; so our formulation
can be applied directly only to systems for which the state-space dimension
takes such a value. Though this condition may seem limiting, we note that any
quantum computer based on qubits meets the condition and can thus be
accommodated within our scheme. The geometry of our N x N phase space also
leads naturally to a method of constructing a complete set of N+1 mutually
unbiased bases for the state space.Comment: 60 pages; minor corrections and additional references in v2 and v3;
improved historical introduction in v4; references to quantum error
correction in v5; v6 corrects the value quoted for the number of similarity
classes for N=
Racial and ethnic disparities in the control of cardiovascular disease risk factors in Southwest American veterans with type 2 diabetes: the Diabetes Outcomes in Veterans Study
BACKGROUND: Racial/ethnic disparities in cardiovascular disease complications have been observed in diabetic patients. We examined the association between race/ethnicity and cardiovascular disease risk factor control in a large cohort of insulin-treated veterans with type 2 diabetes. METHODS: We conducted a cross-sectional observational study at 3 Veterans Affairs Medical Centers in the American Southwest. Using electronic pharmacy databases, we randomly selected 338 veterans with insulin-treated type 2 diabetes. We collected medical record and patient survey data on diabetes control and management, cardiovascular disease risk factors, comorbidity, demographics, socioeconomic factors, psychological status, and health behaviors. We used analysis of variance and multivariate linear regression to determine the effect of race/ethnicity on glycemic control, insulin treatment intensity, lipid levels, and blood pressure control. RESULTS: The study cohort was comprised of 72 (21.3%) Hispanic subjects (H), 35 (10.4%) African Americans (AA), and 226 (67%) non-Hispanic whites (NHW). The mean (SD) hemoglobin A1c differed significantly by race/ethnicity: NHW 7.86 (1.4)%, H 8.16 (1.6)%, AA 8.84 (2.9)%, p = 0.05. The multivariate-adjusted A1c was significantly higher for AA (+0.93%, p = 0.002) compared to NHW. Insulin doses (unit/day) also differed significantly: NHW 70.6 (48.8), H 58.4 (32.6), and AA 53.1 (36.2), p < 0.01. Multivariate-adjusted insulin doses were significantly lower for AA (-17.8 units/day, p = 0.01) and H (-10.5 units/day, p = 0.04) compared to NHW. Decrements in insulin doses were even greater among minority patients with poorly controlled diabetes (A1c ≥ 8%). The disparities in glycemic control and insulin treatment intensity could not be explained by differences in age, body mass index, oral hypoglycemic medications, socioeconomic barriers, attitudes about diabetes care, diabetes knowledge, depression, cognitive dysfunction, or social support. We found no significant racial/ethnic differences in lipid or blood pressure control. CONCLUSION: In our cohort, insulin-treated minority veterans, particularly AA, had poorer glycemic control and received lower doses of insulin than NHW. However, we found no differences for control of other cardiovascular disease risk factors. The diabetes treatment disparity could be due to provider behaviors and/or patient behaviors or preferences. Further research with larger sample sizes and more geographically diverse populations are needed to confirm our findings
The Orbit and Occultations of KH 15D
The unusual flux variations of the pre-main-sequence binary star KH 15D have
been attributed to occultations by a circumbinary disk. We test whether or not
this theory is compatible with newly available data, including recent radial
velocity measurements, CCD photometry over the past decade, and photographic
photometry over the past 50 years. We find the model to be successful, after
two refinements: a more realistic motion of the occulting feature, and a halo
around each star that probably represents scattering by the disk. The occulting
feature is exceptionally sharp-edged, raising the possibility that the dust in
the disk has settled into a thin layer, and providing a tool for fine-scale
mapping of the immediate environment of a T Tauri star. However, the window of
opportunity is closing, as the currently visible star may be hidden at all
orbital phases by as early as 2008.Comment: To appear in ApJ [16 pages, 13 figures
The energy scale of inflation: is the hunt for the primordial B-mode a waste of time?
Recent theoretical results indicate that the detection of primordial gravity
waves from inflation may be a hopeless task. First, foregrounds from lensing
put a strict lower limit on the detectability of the B-mode polarization signal
in the Cosmic Microwave Background, the ``smoking gun'' for tensor (gravity
wave) fluctuations. Meanwhile, widely accepted theoretical arguments indicate
that the amplitude of gravity waves produced in inflation will be below this
limit. I argue that failure is not inevitable, and that the effort to detect
the primordial signal in the B-mode, whether it succeeds or fails, will yield
crucial information about the nature of inflation.Comment: To be published in the proceedings of "The Cosmic Microwave
Background and its Polarization", New Astronomy Reviews, (eds. S. Hanany and
K.A. Olive). 10 pp., 7 figure
Editorial: Combined Modality Treatment of Resectable and Borderline Resectable Pancreas Cancer: Expert Consensus Conference
Brief Report: The Value of a Patient Global Assessment of Disease Activity in Granulomatosis With Polyangiitis (Wegener's)
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/102695/1/art38248.pd
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