7,360 research outputs found
Management system requirements for wireless systems beyond 3G
This paper presents a comprehensive description of various management system requirements for systems beyond 3G, which have been identified as a result of the Software Based Systems activities within the Mobile VCE Core 2 program. Specific requirements for systems beyond 3G are discussed and potential technologies to address them proposed. The analysis has been carried out from network, service and security viewpoints
Aggregates of two-dimensional vesicles: Rouleaux and sheets
Using both numerical and variational minimization of the bending and adhesion
energy of two-dimensional lipid vesicles, we study their aggregation, and we
find that the stable aggregates include an infinite number of vesicles and that
they arrange either in a columnar or in a sheet-like structure. We calculate
the stability diagram and we discuss the modes of transformation between the
two types of aggregates, showing that they include disintegration as well as
intercalation.Comment: 4 figure
Exobiology in Earth orbit: The results of science workshops held at NASA, Ames Research Center
The Workshops on Exobiology in Earth Orbit were held to explore concepts for orbital experiments of exobiological interest and make recommendations on which classes of experiments should be carried out. Various observational and experimental opportunities in Earth orbit are described including those associated with the Space Shuttle laboratories, spacecraft deployed from the Space Shuttle and expendable launch vehicles, the Space Station, and lunar bases. Specific science issues and technology needs are summarized. Finally, a list of recommended experiments in the areas of observational exobiology, cosmic dust collection, and in situ experiments is presented
A Vitamin C Study of Malay Schoolboys in the Coastal Region of North Perak, Malaya
Malay schoolboys in the coastal region of Perak were investigated as to the presence of vitamin C deficiency. Although the subjects were drawn from that part of the population of Malaya most prone to this deficiency, only a few showed subnormal excretions of ascorbic acid in the urine. Few of the abnormal clinical signs noted in the boys could be attributed to lack of the vitamin. Special tests for detecting vitamin C deficiency did not give satisfactory results
Minimal norm constrained interpolation
In computational fluid dynamics and in CAD/CAM, a physical boundary is usually known only discreetly and most often must be approximated. An acceptable approximation preserves the salient features of the data such as convexity and concavity. In this dissertation, a smooth interpolant which is locally concave where the data are concave and is locally convex where the data are convex is described. The interpolant is found by posing and solving a minimization problem whose solution is a piecewise cubic polynomial. The problem is solved indirectly by using the Peano Kernal theorem to recast it into an equivalent minimization problem having the second derivative of the interpolant as the solution. This approach leads to the solution of a nonlinear system of equations. It is shown that Newton's method is an exceptionally attractive and efficient method for solving the nonlinear system of equations. Examples of shape-preserving interpolants, as well as convergence results obtained by using Newton's method are also shown. A FORTRAN program to compute these interpolants is listed. The problem of computing the interpolant of minimal norm from a convex cone in a normal dual space is also discussed. An extension of de Boor's work on minimal norm unconstrained interpolation is presented
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