Sökning: "differentialekvationer"

Visar resultat 1 - 5 av 54 avhandlingar innehållade ordet differentialekvationer.

  1. 1. Exploring the Effects of ICT on Environmental Sustainability: From Life Cycle Assessment to Complex Systems Modeling

    Författare :Mohammad Ahmadi Achachlouei; Åsa Moberg; Göran Finnveden; Lorenz M. Hilty; Chris Preist; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Information and communication technology ICT ; sustainability assessment; electronic media; tablet; print media; magazine; Internet; energy; environmental impact; life cycle assessment LCA ; System Dynamics; agent-based modeling; differential equations; simulation modeling; complex and dynamic systems modeling; Informations- och kommunikationsteknik IKT ; hållbarhetsbedömning; elektroniska media; surfplatta; tryckta media; tidskrift; Internet; energi; miljöpåverkan; simulering; differentialekvationer; modellering av komplexa och dynamiska system; System Dynamics; livscykelanalys LCA ; agentbaserad modellering; Planering och beslutsanalys; Planning and Decision Analysis; Informations- och kommunikationsteknik; Information and Communication Technology; Industriell ekologi; Industrial Ecology; Tillämpad matematik och beräkningsmatematik; Applied and Computational Mathematics;

    Sammanfattning : The production and consumption of information and communication technology (ICT) products and services continue to grow worldwide. This trend is accompanied by a corresponding increase in electricity use by ICT, as well as direct environmental impacts of the technology. Yet a more complicated picture of ICT’s effects is emerging. LÄS MER

  3. 2. Titchmarsh-Weyl M-function asymptotics and some results in the inverse spectral theory for vector-valued Sturm-Liouville equations and a certain higher order ordinary differential equation

    Författare :Erik Andersson; Matematik (naturvetenskapliga fakulteten); []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Functions; differential equations; Funktioner; differentialekvationer; Paley-Wiener.; The generalized Fourier transform; A certain higher order ordinary differential equation; Borg-Marchenko theorems; Vector-valued Sturm-Liouville equations; Inverse spectral theory; Titchmarsh-Weyl M-function asymptotics; Asymptotics of solutions; Spectral measure;

    Sammanfattning : This discourse is constituted by two separate reprots, where the first one offers an elementary deduction of the leading order term asymptotics for the Titchmarsh-Weyl M-function corresponding to a vector-valued Sturm-Liouville equation of the form -(PU')'+QU=zu, xin[0,b), with P^{-1},W,Q being hermitean with locally integrable entries; and under some additional conditions on P^{-1} and W. In the special case of P=W=I, we give some further asymptotic results for the same M-function. LÄS MER

  4. 3. Local Polynomial Regression with Application on Lidar Measurements

    Författare :Torgny Lindström; Matematisk statistik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Mathematics; Matematik; differential equations; Funktioner; differentialekvationer; variance-function estimation.; spatial dependence; nonparametric; local polynomial regression; local bandwidth selection; lidar; heteroscedasticity; Bivariate estimation; differential absorption; Functions;

    Sammanfattning : This thesis deals with the problem of estimating a function or one of its derivatives from a set of measurements, mainly of a bivariate or spatial nature which is so common in environmental applications. In this work particular attention has been on the lidar (light detection and ranging) application which is a versatile technique for measurement of among other things atmospheric trace gases. LÄS MER

  5. 4. Obstacle Problems for Green Potentials and for Parabolic Quasiminima

    Författare :Catarina Petersson; Matematik (naturvetenskapliga fakulteten); []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Functions; differential equations; Funktioner; differentialekvationer; Matematik; degenerate parabolic operators; Mathematics; quasiminima; obstacle problems; Green potentials;

    Sammanfattning : The thesis consists of two parts. In the first part pure potential theoretic methods are employed to study the obstacle problem connected with a uniformly elliptic second-order differential operator in divergence form. Regular points of the obstacles are characterized by the classical Wiener criterion. LÄS MER

  7. 5. Regularity of multilinear oscillatory integral operators and nonlinear dispersive partial differential equations

    Författare :Aksel Bergfeldt; Wolfgang Staubach; Dorothee Frey; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; oscillatory integral operators; partial differential equations; Mathematics; Matematik;

    Sammanfattning : We show regularity of multilinear Schrödinger integral operators as well as multilinear oscillatory integrals with connection to dispersive partial differential equations. These results are used to show regularity of a system of nonlinear dispersive partial differential equations... LÄS MER