An extensive English language bibliography on graph theory and its applications

Bibliography on graph theory and its application

Data bases and data base systems related to NASA's aerospace program. A bibliography with indexes

This bibliography lists 1778 reports, articles, and other documents introduced into the NASA scientific and technical information system, 1975 through 1980

Dirichlet problems for several nonlocal operators via variational and topological methods

The main topic of the thesis is the study of elliptic differential equations with fractional order driven by nonlocal operators, as the fractional p-Laplacian, the fractional Laplacian for p=2, the general nonlocal operator and its anisotropic version. Recently, great attention has been focused on the study of fractional and nonlocal operators of elliptic type, both for pure mathematical research and in view of concrete real-world applications. This type of operators arises in a quite natural way in many different contexts, such as, among others, game theory, image processing, optimization, phase transition, anomalous diffusion, crystal dislocation, water waves, population dynamics and geophysical fluid dynamics. The main reason is that nonlocal operators are the infinitesimal generators of Lévy-type stochastic processes. Such processes extend the concept of Brownian motion, where the infinitesimal generator is the Laplace operator, and may contain jump discontinuities. Our aim is to show existence and multiplicity results for nonlinear elliptic Dirichlet problems, driven by a nonlocal operator, by applying variational and topological methods. Such methods usually exploit the special form of the nonlinearities entering the problem, for instance its symmetries, and offer complementary information. They are powerful tools to show the existence of multiple solutions and establish qualitative results on these solutions, for instance information regarding their location. The topological and variational approach provides not just existence of a solution, usually several solutions, but allow to achieve relevant knowledge about the behavior and properties of the solutions, which is extremely useful because generally the problems cannot be effectively solved, so the precise expression of the solutions is unknown. As a specific example of property of a solution that we look for is the sign of the solution, for example to be able to determine whether it is positive, or negative, or nodal (i.e., sign changing)

The learning of general mathematical strategies: a developmental study of process attainments in mathematics, including the construction and investigation of a process-oriented curriculum for the first secondary year

Consideration of the relative place of content and process in the mathematics curriculum leads to the following questions: 1. What is the nature of the mathematical process and how does it relate to the content? 2. Does the process comprise learnable strategies; if so, what are feasible learning objectives for different ages? 3. Can content and process be learned simultaneously or are there incompatibilities between effective teaching methods? A theoretical study shows that the content of mathematics - structures, symbol-systems and models - arises directly from the application of the basic processes of generalisation and abstraction, symbolisation and modelling, to the objects of experience. Experimental studies based on (a) the development of a process-enriched curriculum for the early secondary years, and (b) age and ability cross-sectional studies of pupils' proof activity show that: i. the awareness that proof requires consideration of all cases is generally weak among secondary pupils, but is relatively easily taught, ii. with a process-enriched curriculum, 11 year olds can acquire strategies of experimenting, making generalisations and constructing complete (finite) sets but still have little sense of deducing one result from another, iii. the main types of deficiency in proof-explanations are (a) fragmentary arguments, (b) non-explanatory re-statements of the data, (c) unawareness of suitable starting assumptions. Strategies for improving proof activity are inferred from pupils' responses, and are shown to be effective in a sixth form teaching experiment. An informal study shows that students entering university mathematics departments possess generalisation skills and logical awareness to a much higher degree than 15 year olds, but still have only vague ideas of the nature of axiom systems. On question 3 the evidence suggests that there need be no substantial loss of content learning in the process-enriched curriculum, and both in this and in the teaching experiment an improvement in general understanding and involvement was observed

New Developments Regarding the KT Event and Other Catastrophes in Earth History

Papers presented at the conference on New Developments Regarding the KT Event and Other Catastrophes in Earth History are included. Topics covered include: trajectories of ballistic impact ejecta on a rotating earth; axial focusing of impact energy in the earth's interior: proof-of-principle tests of a new hypothesis; in search of Nemesis; impact, extinctions, volcanism, glaciations, and tectonics: matches and mismatches

The learning of general mathematical strategies: a developmental study of process attainments in mathematics, including the construction and investigation of a process-oriented curriculum for the first secondary year

Consideration of the relative place of content and process in the mathematics curriculum leads to the following questions: 1. What is the nature of the mathematical process and how does it relate to the content? 2. Does the process comprise learnable strategies; if so, what are feasible learning objectives for different ages? 3. Can content and process be learned simultaneously or are there incompatibilities between effective teaching methods? A theoretical study shows that the content of mathematics - structures, symbol-systems and models - arises directly from the application of the basic processes of generalisation and abstraction, symbolisation and modelling, to the objects of experience. Experimental studies based on (a) the development of a process-enriched curriculum for the early secondary years, and (b) age and ability cross-sectional studies of pupils' proof activity show that: i. the awareness that proof requires consideration of all cases is generally weak among secondary pupils, but is relatively easily taught, ii. with a process-enriched curriculum, 11 year olds can acquire strategies of experimenting, making generalisations and constructing complete (finite) sets but still have little sense of deducing one result from another, iii. the main types of deficiency in proof-explanations are (a) fragmentary arguments, (b) non-explanatory re-statements of the data, (c) unawareness of suitable starting assumptions. Strategies for improving proof activity are inferred from pupils' responses, and are shown to be effective in a sixth form teaching experiment. An informal study shows that students entering university mathematics departments possess generalisation skills and logical awareness to a much higher degree than 15 year olds, but still have only vague ideas of the nature of axiom systems. On question 3 the evidence suggests that there need be no substantial loss of content learning in the process-enriched curriculum, and both in this and in the teaching experiment an improvement in general understanding and involvement was observed

New Developments Regarding the KT Event and Other Catastrophes in Earth History

Topics covered include: trajectories of ballistic impact ejecta on a rotating earth; axial focusing of impact energy in the Earth's interior: proof-of-principle tests of a new hypothesis; in search of Nemesis; impact, extinctions, volcanism, glaciations, and tectonics: matches and mismatches.sponsored by Lunar and Planetary Institute, University of Houston-Clear Lake.PARTIAL CONTENTS: Tsunami Deposits and the KT Boundary: A Sedimentologist's Perspective / J. Bourgeois -- New Evidence for Terrestrial Ecosystem Collapse at the KT and Permian/Triassic Boundaries / H. Brinkhuis and H. Visscher -- Rift-flooding Episodes Around 65 Ma as Causes of Abrupt Sea-Level Falls: Did the KT Impact Happen During a Time of Frequent Catastrophes? / K. Burke -- In Search of Nemesis / S. Carlson, T. Culler, R.A. Mulier, M. Tetreault, and S. Perlmutter -- New Mineralogical and Chemical Constraints on the Nature of Target Rocks at the Chicxulub Crater / E. Cedillo P.P. Claeys, J.M. Grajales-N., and W. Alvarez -- Sulfur Isotope Study of High-Calcium Impact Glasses from the KT Boundary / M. Chaussidon, H. Sigurdsson, and N. Metrich

Collection of abstracts of the 24th European Workshop on Computational Geometry

International audienceThe 24th European Workshop on Computational Geomety (EuroCG'08) was held at INRIA Nancy - Grand Est & LORIA on March 18-20, 2008. The present collection of abstracts contains the 63 scientific contributions as well as three invited talks presented at the workshop