| 951. |
- Maz´ya, Vladimir, et al.
(författare)
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Green's Kernels and Meso-Scale Approximations in Perforated Domains
- 2013
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Bok (refereegranskat)abstract
- Systematic step-by-step approach to asymptotic algorithms that enables the reader to develop an insight to compound asymptotic approximations Presents a novel, well-explained method of meso-scale approximations for bodies with non-periodic multiple perforations Contains illustrations and numerical examples for a range of physically realisable configurations.There are a wide range of applications in physics and structural mechanics involving domains with singular perturbations of the boundary. Examples include perforated domains and bodies with defects of different types. The accurate direct numerical treatment of such problems remains a challenge. Asymptotic approximations offer an alternative, efficient solution. Green’s function is considered here as the main object of study rather than a tool for generating solutions of specific boundary value problems. The uniformity of the asymptotic approximations is the principal point of attention. We also show substantial links between Green’s functions and solutions of boundary value problems for meso-scale structures. Such systems involve a large number of small inclusions, so that a small parameter, the relative size of an inclusion, may compete with a large parameter, represented as an overall number of inclusions.The main focus of the present text is on two topics: (a) asymptotics of Green’s kernels in domains with singularly perturbed boundaries and (b) meso-scale asymptotic approximations of physical fields in non-periodic domains with many inclusions. The novel feature of these asymptotic approximations is their uniformity with respect to the independent variables.This book addresses the needs of mathematicians, physicists and engineers, as well as research students interested in asymptotic analysis and numerical computations for solutions to partial differential equations.
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| 952. |
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| 953. |
- Maz´ya, Vladimir, 1937-, et al.
(författare)
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Theory of Sobolev Multipliers : with Applications to Differential and Integral Operators
- 2008
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Bok (övrigt vetenskapligt/konstnärligt)abstract
- The purpose of this book is to give a comprehensive exposition of the theory of pointwise multipliers acting in pairs of spaces of differentiable functions. The theory was essentially developed by the authors during the last thirty years and the present volume is mainly based on their results. Part I is devoted to the theory of multipliers and encloses the following topics: trace inequalities, analytic characterization of multipliers, relations between spaces of Sobolev multipliers and other function spaces, maximal subalgebras of multiplier spaces, traces and extensions of multipliers, essential norm and compactness of multipliers, and miscellaneous properties of multipliers. Part II concerns several applications of this theory: continuity and compactness of differential operators in pairs of Sobolev spaces, multipliers as solutions to linear and quasilinear elliptic equations, higher regularity in the single and double layer potential theory for Lipschitz domains, regularity of the boundary in $L_p$-theory of elliptic boundary value problems, and singular integral operators in Sobolev spaces.
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| 954. |
- Maz'ya, Vladimir
(författare)
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Sobolev spaces : with applications to elliptic partial differential equations
- 2011. - 2
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Bok (refereegranskat)abstract
- Sobolev spaces play an outstanding role in modern analysis, in particular, in the theory of partial differential equations and its applications in mathematical physics. They form an indispensable tool in approximation theory, spectral theory, differential geometry etc. The theory of these spaces is of interest in itself being a beautiful domain of mathematics. The present volume includes basics on Sobolev spaces, approximation and extension theorems, embedding and compactness theorems, their relations with isoperimetric and isocapacitary inequalities, capacities with applications to spectral theory of elliptic differential operators as well as pointwise inequalities for derivatives. The selection of topics is mainly influenced by the author’s involvement in their study, a considerable part of the text is a report on his work in the field. Part of this volume first appeared in German as three booklets of Teubner-Texte zur Mathematik (1979, 1980). In the Springer volume “Sobolev Spaces”, published in English in 1985, the material was expanded and revised. The present 2nd edition is enhanced by many recent results and it includes new applications to linear and nonlinear partial differential equations. New historical comments, five new chapters and a significantly augmented list of references aim to create a broader and modern view of the area.
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| 955. |
- McGee, Fintan, et al.
(författare)
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Visual Analysis of Multilayer Networks
- 2021
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Bok (övrigt vetenskapligt/konstnärligt)abstract
- The emergence of multilayer networks as a concept from the field of complex systems provides many new opportunities for the visualization of network complexity, and has also raised many new exciting challenges. The multilayer network model recognizes that the complexity of relationships between entities in real-world systems is better embraced as several interdependent subsystems (or layers) rather than a simple graph approach. Despite only recently being formalized and defined, this model can be applied to problems in the domains of life sciences, sociology, digital humanities, and more. Within the domain of network visualization there already are many existing systems, which visualize data sets having many characteristics of multilayer networks, and many techniques, which are applicable to their visualization. In this Synthesis Lecture, we provide an overview and structured analysis of contemporary multilayer network visualization. This is not only for researchers in visualization, but also for those who aim to visualize multilayer networks in the domain of complex systems, as well as those solving problems within application domains. We have explored the visualization literature to survey visualization techniques suitable for multilayer network visualization, as well as tools, tasks, and analytic techniques from within application domains. We also identify the research opportunities and examine outstanding challenges for multilayer network visualization along with potential solutions and future research directions for addressing them.
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| 956. |
- Medin, Jennie, 1972-, et al.
(författare)
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Begreppen Hälsa och Hälsofrämjande - en litteraturstudie.
- 2001
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Bok (övrigt vetenskapligt/konstnärligt)abstract
- Begreppen hälsa och hälsofrämjande används alltmer i olika måldokument på lokal, nationell och internationell nivå. Det är dock sällan som begreppen definieras. Detta har inneburit en stor osäkerhet kring vad som egentligen avses med dessa begrepp och denna osäkerhet har ibland skapat irritation över vad som uppfattats som ”flummigt” och vagt kring hälsa.Denna bok är en litteraturgenomgång av olika teorier om och definitioner av hälsa och hälsofrämjande. Teorier och definitioner förklaras och klassificeras utifrån termer som holistisk, biostatistisk, teleologisk, strategi, handling o.s.v. Vi belyser frågor som: Är hälsa motsatsen till sjukdom? Är hälsa något annat än frånvaro av sjukdom? Går den att förklara med termer som handlingsförmåga, välbefinnande eller mening? Finns det någon skillnad mellan hälsofrämjande och prevention? Vad kan olika hälsosyner ha för inverkan på mötet med patienter, klienter etc.Målgruppen omfattar blivande och praktiserande läkare, sköterskor, folkhälsovetare, arbetsterapeuter, socionomer och andra yrkesgrupper som professionellt arbetar med hälsa och hälsofrämjande.
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| 957. |
- Melin, Tomas, 1975-
(författare)
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Parametric Airfoil Catalog Part I, Archer A18 to Göttingen 655 : An Aerodynamic and Geometric Comparison Between Parametrized and Point Cloud Airfoils
- 2013. - 1
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Bok (övrigt vetenskapligt/konstnärligt)abstract
- A fundamental part of aircraft design involves wing airfoiloptimization, establishing an outer shape of the wing which has good aerodynamic performance for the design mission, good internal volume distribution for fuel and systems and which also serves as an efficient structural member supporting the load of the weight of the aircraft. The underlying idea with this parametrization is to couple an appropriate number of parameters, balancing the need of geometric accuracy with the necessity of few airfoil parameters in order to facilitate en expedient optimisation, with the intrinsic value of having parameters that makes sense for a human; such as thickness, camber and trailing edge thickness. Several approaches to parametrization of wing proles can be found in the literature. Airfoils can be described by point clouds as done in most airfoil libraries. The number of parameters is twice as large as the number of points used (x and y coordinates) and in the case of aerodynamic optimization this parametrization will most certainly be not well behaved, since no smoothing function is included and must therefore be employed. Other problems may arise for the fact that the airfoils sometimes are defined with too few coordinate points and/or too few decimals, a problem occurring especially with old airfoils. On the other hand, the design space that this kind of parametrization allows representing is extremely large, as any and all shapes can be reproduced, even degenerate ones. Airfoils can also be represented by mathematical functions. Among the most common representatives of thiscategory are indeed the NACA 4-, 5- and 6-digits formulations. Compared to point clouds, they could be said to represent the opposite case: they are very well behaving parametrizations, but they cannot cover avery large design space, since they only provide four to six parameters respectively to be tuned. The NACA 4digit series is particularly interesting as the parametersare a part of the name of the airfoil. In the case of the 5- and 6 digit series, the name is instead constructed from the airfoils aerodynamic characteristic and geometry. Another known set of theoretically defined airfoils are the Joukowski profiles [4]. Using the conformal mapping method, airfoils with a round nose and sharp trailing edge can be represented. Sadly the method is not to recommend for trying to match known airfoils and the design space it describes is quite confined to airfoils with often poor performances.
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| 958. |
- Melin, Tomas, 1975-
(författare)
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Parametric Airfoil Catalog, Part II: Göttingen 673 to YS930 : An Aerodynamic and Geometric Comparison Between Parametrized and Point Cloud Airfoils
- 2013
-
Bok (övrigt vetenskapligt/konstnärligt)abstract
- A fundamental part of aircraft design involves wing airfoiloptimization, establishing an outer shape of the wing which has good aerodynamic performance for the design mission, good internal volume distribution for fuel and systems and which also serves as an efficient structural member supporting the load of the weight of the aircraft. The underlying idea with this parametrization is to couple an appropriate number of parameters, balancing the need of geometric accuracy with the necessity of few airfoil parameters in order to facilitate en expedient optimisation, with the intrinsic value of having parameters that makes sense for a human; such as thickness, camber and trailing edge thickness. Several approaches to parametrization of wing proles can be found in the literature. Airfoils can be described by point clouds as done in most airfoil libraries. The number of parameters is twice as large as the number of points used (x and y coordinates) and in the case of aerodynamic optimization this parametrization will most certainly be not well behaved, since no smoothing function is included and must therefore be employed. Other problems may arise for the fact that the airfoils sometimes are defined with too few coordinate points and/or too few decimals, a problem occurring especially with old airfoils. On the other hand, the design space that this kind of parametrization allows representing is extremely large, as any and all shapes can be reproduced, even degenerate ones. Airfoils can also be represented by mathematical functions. Among the most common representatives of thiscategory are indeed the NACA 4-, 5- and 6-digits formulations. Compared to point clouds, they could be said to represent the opposite case: they are very well behaving parametrizations, but they cannot cover avery large design space, since they only provide four to six parameters respectively to be tuned. The NACA 4digit series is particularly interesting as the parametersare a part of the name of the airfoil. In the case of the 5- and 6 digit series, the name is instead constructed from the airfoils aerodynamic characteristic and geometry. Another known set of theoretically defined airfoils are the Joukowski profiles [4]. Using the conformal mapping method, airfoils with a round nose and sharp trailing edge can be represented. Sadly the method is not to recommend for trying to match known airfoils and the design space it describes is quite confined to airfoils with often poor performances.
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| 959. |
- Melin, Ulf, et al.
(författare)
-
Frågor om tillit ... : praktik, teknik och organisation i samspel kring säkra offentliga e-tjänster : en diskussionsbok baserad på forskningsprojektet "Säkra offentliga e-tjänster - en fråga om tillit och organisering" vid Linköpings universitet 2008-2011
- 2011
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Bok (övrigt vetenskapligt/konstnärligt)abstract
- Idag är det Helt okej att lämna in deklarationen på nätet eller via ett SMS. Lika vanligt är det att i första hand gå till en kommuns hemsida för att hitta öppettider på atervinningsstationen, leta böcker i bibliotekets katalog eller för att söka upp telefonnumret till socialförvaltningen. Detta är exempel på offentliga e-tjänster.Offentliga e-tjänster är tjänster då informations- och kommunikationsteknik används i relationer mellan offentlig förvaltning och medborgare.Men det är inte alltid så att offentliga e-tjänster bara ökar tillgänglighet och effektiviserar förvaltningen. Hur görs de säkra? Kan alla använda dessa tjänster på samma sätt? Behöver de som arbetar i förvaltningen ändra sina sätt att arbeta? Skapas nya sätt att fuska? Hamnar de offentliga organisationerna i händerna på företagen som utvecklar tekniken?Det finns många problem och utmaningar med offentliga e-tjänster. I denna bok diskuterar forskare från Linköpings universitet hur utmaningar kring tilllit till offentliga e-tjänster kan tolkas och kanske även hanteras. Forskare från statsvetenskap och informatik har samarbetat. Här får Du en del svar och tips, men även frågor och nya perspektiv som kan vara viktiga för Dig som utvecklar, arbetar med eller bara nyttjar offentliga e-tjänster.
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| 960. |
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