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The paper is devoted to pseudodifferential boundary value problems in domains with singular points on the boundary. The tangent cone at a singular point is allowed to degenerate. In particular, the boundary may rotate and oscillate in a neighbourhood of such a point. We show a criterion for the Fredholm property of a boundary value problem and derive estimates of solutions close to singular points.
Abschließende Bemerkungen des Menschenrechtsausschusses zum Bericht Deutschlands gemäß Art. 40 CCPR
(1997)
Three-dimensional bouyancy-driven convection in a horizontal fluid layer with stress-free boundary conditions at the top and bottom and periodic boundary conditions in the horizontal directions is investigated by means of numerical simulation and bifurcation-analysis techniques. The aspect ratio is fixed to a value of 2√2 and the Prandtl number to a value of 6.8. Two-dimensional convection rolls are found to be stable up to a Rayleigh number of 17 950, where a Hopf bifurcation leads to traveling waves. These are stable up to a Rayleigh number of 30 000, where a secondary Hopf bifurcation generates modulated traveling waves. We pay particular attention to the symmetries of the solutions and symmetry breaking by the bifurcations.
We have studied the bifurcation structure of the incompressible two-dimensional Navier-Stokes equations with a special external forcing driving an array of 8×8 counterrotating vortices. The study has been motivated by recent experiments with thin layers of electrolytes showing, among other things, the formation of large-scale spatial patterns. As the strength of the forcing or the Reynolds number is raised the original stationary vortex array becomes unstable and a complex sequence of bifurcations is observed. The bifurcations lead to several periodic branches, torus and chaotic solutions, and other stationary solutions. Most remarkable is the appearance of solutions characterized by structures on spatial scales large compared to the scale of the forcing. We also characterize the different dynamic regimes by means of tracers injected into the fluid. Stretching rates and Hausdorff dimensions of convected line elements are calculated to quantify the mixing process. It turns out that for time-periodic velocity fields the mixing can be very effective.
Two-dimensional bouyancy-driven convection in a horizontal fluid layer with stress-free boundary conditions at top and bottom and periodic boundary conditions in the horizontal direction is investigated by means of numerical simulation and bifurcation-analysis techniques. As the bouyancy forces increase, the primary stationary and symmetric convection rolls undergo successive Hopf bifurcations, bifurcations to traveling waves, and phase lockings. We pay attention to symmetry breaking and its connection with the generation of large-scale horizontal flows. Calculations of Lyapunov exponents indicate that at a Rayleigh number of 2.3×105 no temporal chaos is reached yet, but the system moves nonchaotically on a 4-torus in phase space.
The dynamics of noisy bistable systems is analyzed by means of Lyapunov exponents and measures of complexity. We consider both the classical Kramers problem with additive white noise and the case when the barrier fluctuates due to additional external colored noise. In case of additive noise we calculate the Lyapunov exponents and all measures of complexity analytically as functions of the noise intensity resp. the mean escape time. For the problem of fluctuating barrier the usual description of the dynamics with the mean escape time is not sufficient. The application of the concept of measures of complexity allows to describe the structures of motion in more detail. Most complexity measures sign the value of correlation time at which the phenomenon of resonant activation occurs with an extremum.
After overcoming the divergence from the general features of Western and international urban development caused by Germany's division, Berlin is catching up with and imitating almost all features of post-modern city formation constituted and demonstrated in the last two decades. Berlin is trying to make good its backwardness and to keep abreast of the metropolis in Europe and the world through a strategy aimed at a cultural re-evaluation of urban structure and architecture. The so-called Prussian style based on the Classicist tradition of the beginning of the 19th century is the historical and asthetic horizon. A small administrative and architectural elite pushing the redefinition of the social, political and asthetic meaning of public space ignores consciously the architectural reality in the Eastern and Western parts of the city. Crucial objectives are the cultural, political and economic recapturing of the traditional centre of Berlin profoundly marked by its socialist past and the protection of middle class interests.
The attitude of the East Germans to the Polish is burdened with the heritage of the past. After 1945 the composition of the population on both sides of the new border along the Oder and Neisse rivers changed drastically. On the eastern side the Germans were expelled and Polish people were settled. On the western side many expelled Germans found a new home. Despite the fact that the GDR signed the Oder-Neisse border treaty, the ruling communist party (SED) did not encourage contacts between the people living on both sides of Oder and Neisse in the following years. The policy of the SED towards the Polish communists during the whole period between 1946-1989 was characterised by arrogance and suspicion, at times falling back on old anti-Polish stereotypes. Especially in the 1980s, the GDR tried to prevent the influence of Solidarnosc and dissident ideas from entering the country. Despite this policy, substantial personal contacts developed, particularly in the 1970s when the border was fully opened. The authors argue that current German-Polish relations should make use of these experiences.
Die Kinderrechtskonvention
(1997)
Lineare Modelle mit latenten Variablen sind seit langem verbreitete Analyse- und Prognoseinstrumente in den Sozialwissenschaften. Auch in der Ökonometrie gibt es einige Anwendungen. Die meistverbreiteten Modellierungs- und Schätzverfahren sind LISREL von Jöreskog und Sörbom (z.B. 1987) und Partial Least Squares (PLS) von H. Wold (1973). Während LISREL mehr modellorientiert und in der Anwendung konfirmativ ist, kann man PLS als datenorientiert und eher deskriptiv oder explorativ bezeichnen. Charakteristisch für Wolds Herangehen ist, daß das PLS-Modell eigentlich nur durch den Algorithmus zu seiner Schätzung definiert wird. Das umfassendste Programmsystem für PLS ist LVPLS von J. B. Lohmöller (1984). Es lehnt sich sehr eng an die Theorie von Wold an und ist trotz mangelnden Nutzerkomforts in seiner Vielseitigkeit und Zuverlässigkeit unübertroffen. Weder Wolds Verfahren noch Lohmöllers Programm sehen die Anwendung auf dynamische Modelle, etwa VARs, explizit vor. Die Einbeziehung verzögerter Variablen ist nur in Form selbständiger Variablen möglich, was zu Inkonsistenzen bei der Gewichtung führt. Im folgenden zweiten Abschnitt wird ein Verfahren skizziert (vgl. Strohe 1995), das sich einerseits sehr eng an den Woldschen Algorithmus anlehnt, das aber andererseits speziell auf die Behandlung von dynamischen Modellen mit verzögerten latenten Variablen ausgerichtet ist. Der dritte Abschnitt bringt dann eine Einführung in das entsprechende ISP™ Computerprogramm DPLS (vgl. Geppert 1995). Er besteht aus einer allgemeinen Programmbeschreibung und einer detaillierten Nutzeranleitung. Hinzu kommt die Bearbeitung eines kleinen ökonometrischen Demonstrationsmodells. Im vierten Abschnitt werden mit einer Simulationsstudie die Eigenschaften des Schätzverfahrens DPLS unter verschiedenen Verteilungsannahmen geprüft. Der Anhang bringt die vollständigen Listings der kommentierten Programm-Macros.
Inhaltsübersicht I. Einführung II. Grundlagen und Durchsetzung von völkerrechtlichen Verpflichtungen 1. Vertragliche Verpflichtung 2. Völkergewohnheitsrechtliche Verpflichtung III. Einbettung von Durchsetzungsmaßnahmen in politische und wirtschaftliche Zusammenhänge 1. Berücksichtigung im Rahmen rechtlicher Kontrolle 2. Abstimmung mit anderen Politikzielen IV. Sonderfall: erodierende Staatsgewalt V. Ausblick
The paper is devoted to the construction of the exponential function of a matrix pseudo-differential operator which do not satisfy any of the known theorems (see, Sec.8 Ch.VIII and Sec.2 Ch.XI of [17]). The applications to the construction of the fundamental solution for the Cauchy problem for the hyperbolic operators with the characteristics of variable multiplicity are given, too.
Filmfrauen - Zeitzeichen : Frauenbilder im Film der 40er, 60er und 90er Jahre ; Band II: Arbeiterin
(1997)
Die in den Heften 1-3 der „Potsdamer Studien zur Frauen- und Geschlechterforschung“ publizierten Beiträge sind Ergebnisse eines Projektes, das in den Jahren 1995 bis 1997 im Auftrag des Filmmuseums Potsdam am Lehrstuhl Frauenforschung an der Wirtschafts- und Sozialwissenschaftlichen Fakultät der Universität Potsdam realisiert wurde. Inhalt: England im Aufbruch. Alltagserfahrungen und ökonomische, soziale und kulturelle Rahmenbedingungen in England am Ende der 50er bis zum Anfang der 60er Jahre (Susan Geißler) Die VerliererInnen des Aufbruchs. Wie über AußenseiterInnen die (Geschlechter-)Normen der neuen britischen Mittelschichten diskursiviert werden. - Analyse des Films »Bitterer Honig« (Juliane Rödel) »Wir alle lieben Paula, aber uns liegt an Paul« - Wie über die ‘Weiblichkeit’ einer Arbeiterin der „sozialistische Mensch“ konstruiert wird. Analyse des Films »Die Legende von Paul und Paula« (Irene Dölling)
Filmfrauen - Zeitzeichen : Frauenbilder im Film der 40er, 60er und 90er Jahre ; Band III: Girlie
(1997)
Die in den Heften 1-3 der „Potsdamer Studien zur Frauen- und Geschlechterforschung“ publizierten Beiträge sind Ergebnisse eines Projektes, das in den Jahren 1995 bis 1997 im Auftrag des Filmmuseums Potsdam am Lehrstuhl Frauenforschung an der Wirtschafts- und Sozialwissenschaftlichen Fakultät der Universität Potsdam realisiert wurde. Inhalt: Paulas „Töchter“ on the road. Postmoderne ‘Weiblichkeit’ und sozialer Umbruch im Osten. Analyse des Films »Burning Life« (Irene Dölling) Tank Girl. Die Zähmung einer widerständigen Comicfigur Analyse des Films »Tank Girl« (Ina Dietzsch)
Germany gained its unity, but the restoration of virtual national cohesion presents itself as a lasting problem. The rebuilding of common national identity forms one complex aspect. Particular West and East German political, social and cultural features still exist. The East Germans brought elements of a peculiar identity into the unity; as a repercussion of some setbacks in their position and of some actual inter-German distinctions, their peculiarities are not yet in retreat. They prolong their role as conventional feelings, in temporary behaviours as an answer to their actual stance, and to a certain extent also with traits staged and suggested by entrenched media interpretations about the presently hampered inter-German evolution.
In the rapidly growing literature on globalization, many authors have emphasized the apparent disembedding of social relations from their local-territorial preconditions. Such arguments neglect the relatively fixed and immobile forms of territorial organization upon which the current round of globalization is premised, such as urban-regional agglomerations and territorial states. Drawing on the work of David Harvey and Henri Lefebvre, this article argues that processes of reterritorialization - the reconfiguration of forms of terrritorial organization such as cities and states - must be viewed as an intrinsic moment of the current round of globalization. Globalization is conceived here as a reterritorialization of both socio-economic and political-institutional spaces that unfolds simultaneously upon multiple, superimposed geographical scales. The ongoing restructuring of contemporary urban spaces and state institutional-territorial structures must be viewed at once as presupposition, a medium and an outcome of this highly contested dynamic of global spatial restructuring. New theories and representations of the scaling of spatial practices are needed to grasp the rapidly changing territorial organization of world capitalism in the late 20th century.
Hegemonialmächte im Vorderen und Mittleren Orient : die Dritte Partei in internationalen Konflikten
(1997)
During the last five decades hegemons played an important role in de-escalating international conflicts in the subregion defined as the core of Oriens Islamicus. Statistical analysis of large datasets shows that half of all conflicts remained without any interference from the hegemonial powers at all - both on global scale and in the subregion. In all other cases however, hegemons (especially super-powers in the role of patrons) tended more often to act as (power-) mediators when their client-state was engaged in conflict with a client of the opposing superpower in Oriens Islamicus than they did on global scale. They did this in their own interest in order to avoid direct involvement, i.e. possible danger of a nuclear escalation. In contrast to conventional mediation theory they were more effective in conflict de-escalation than other mediators, especially in conflicts between Israel and its Arab neighbours. The end of bipolarity in the international system also brought this mechanism of de-escalation to an end. It leaves the hegemon(s) as a potentially powerful third party on the one hand, but on the other their inclination to become involved in regional conflict remains rather diminished as long as the basic national interests in the area are not at stake.
The self-awareness of the subject is always dependent on interaction with others. Thus, self-awareness and social awareness are two sides of the same coin. The Self is not only to be won through social ties with others, but at the same time through distance from them. So long as this does not lead to isolation, there is a possibility of working out common values and identities. The construction of common identities is a process of social definition and construction. Materials for this are space-time, social, cultural, economic, and administrative-legal attributes which are transformed into identity-building attributes. Ethnic movements are often portrayed as social dramas. The processes of institution-building and nation-building never stop. Their supporters relate identity management to the central nation-state and consensus, possible minorities count on a strategy of differentiation and conflict instead.
It is shown that the Hankel transformation Hsub(v) acts in a class of weighted Sobolev spaces. Especially, the isometric mapping property of Hsub(v) which holds on L²(IRsub(+),rdr) is extended to spaces of arbitrary Sobolev order. The novelty in the approach consists in using techniques developed by B.-W. Schulze and others to treat the half-line Rsub(+) as a manifold with a conical singularity at r = 0. This is achieved by pointing out a connection between the Hankel transformation and the Mellin transformation.The procedure proposed leads at the same time to a short proof of the Hankel inversion formula. An application to the existence and higher regularity of solutions, including their asymptotics, to the 1-1-dimensional edge-degenerated wave equation is given.
The aim of this book is to develop the Lefschetz fixed point theory for elliptic complexes of pseudodifferential operators on manifolds with edges. The general Lefschetz theory contains the index theory as a special case, while the case to be studied is much more easier than the index problem. The main topics are: - The calculus of pseudodifferential operators on manifolds with edges, especially symbol structures (inner as well as edge symbols). - The concept of ellipticity, parametrix constructions, elliptic regularity in Sobolev spaces. - Hodge theory for elliptic complexes of pseudodifferential operators on manifolds with edges. - Development of the algebraic constructions for these complexes, such as homotopy, tensor products, duality. - A generalization of the fixed point formula of Atiyah and Bott for the case of simple fixed points. - Development of the fixed point formula also in the case of non-simple fixed points, provided that the complex consists of diferential operarators only. - Investigation of geometric complexes (such as, for instance, the de Rham complex and the Dolbeault complex). Results in this direction are desirable because of both purely mathe matical reasons and applications in natural sciences.
Der folgende Diskussionsbeitrag kritisiert Lernanforderungen an die Teilnehmer gewerkschaftlicher Bildungsarbeit, wie sie aus der Perspektive der Lehrenden regelmäßig gesetzt werden, als typische Lernbehinderung für die Bildungsteilnehmer. Diese Lernanforderungen gründen in spezifischen Interessen der Organisation und münden in verschiedenen Formen von Postulatspädagogik, wie sie auch in anderen Feldern politischer Bildung auf der Tagesordnung steht. Abschließend wird ein alternatives, verständigungsorientiertes didaktisches Konzept fallorientierter Weiterbildung vorgestellt, dem eine am Subjekt interessierte Lerntheorie zugrunde liegt.
Lithuania and Poland had cooperated for centuries and even created a political union. The pacts had been very useful for both sides and consequently, the peoples and especially the Lithuanian elite was ready to absorb parts of the Polish culture. Lithuania broke with this tradition dating back to the Middle Ages only after the first division of Poland. During 1944- 1990, the so-called "Soviet period in Lithuania", two different processes could be observed: Russification and Lithuanification. Although dependent on Moscow, the leading Lithuanian politicians never forgot Lithuanian interests and supported the national conscience. After Lithuania gained independence in 1990, a huge wave of national enthusiasm swapped over the country. In the meantime, politicians came back to reality: The independence of Lithuania seems consolidated and the old tradition to re-establish the Polish-Lithuanian cooperation seems to be on the run since Aleksander Kwasniewski had visited Lithuania in January 1996.
Let {Tsub(p) : q1 ≤ p ≤ q2} be a family of consistent Csub(0) semigroups on Lφ(Ω) with q1, q2 ∈ [1, ∞)and Ω ⊆ IRn open. We show that certain commutator conditions on Tφ and on the resolvent of its generator Aφ ensure the φ independence of the spectrum of Aφ for φ ∈ [q1, q2]. Applications include the case of Petrovskij correct systems with Hölder continuous coeffcients, Schrödinger operators, and certain elliptic operators in divergence form with real, but not necessarily symmetric, or complex coeffcients.
We consider a G-invariant star-product algebra A on a symplectic manifold (M,ω) obtained by a canonical construction of deformation quantization. Under assumptions of the classical Marsden-Weinstein theorem we define a reduction of the algebra A with respect to the G-action. The reduced algebra turns out to be isomorphic to a canonical star-product algebra on the reduced phase space B. In other words, we show that the reduction commutes with the canonical G-invariant deformation quantization. A similar statement in the framework of geometric quantization is known as the Guillemin-Sternberg conjecture (by now completely proved).
The usage of nonlinear Galerkin methods for the numerical solution of partial differential equations is demonstrated by treating an example. We desribe the implementation of a nonlinear Galerkin method based on an approximate inertial manifold for the 3D magnetohydrodynamic equations and compare its efficiency with the linear Galerkin approximation. Special bifurcation points, time-averaged values of energy and enstrophy as well as Kaplan-Yorke dimensions are calculated for both schemes in order to estimate the number of modes necessary to correctly describe the behavior of the exact solutions.
We construct a theory of general boundary value problems for differential operators whose symbols do not necessarily satisfy the Atiyah-Bott condition [3] of vanishing of the corresponding obstruction. A condition for these problems to be Fredholm is introduced and the corresponding finiteness theorems are proved.
In the preceding paper we proved an explicit index formula for elliptic pseudodifferential operators on a two-dimensional manifold with conical points. Apart from the Atiyah-Singer integral, it contains two additional terms, one of the two being the 'eta' invariant defined by the conormal symbol. In this paper we clarify the meaning of the additional terms for differential operators.
The paper contains the proof of the index formula for manifolds with conical points. For operators subject to an additional condition of spectral symmetry, the index is expressed as the sum of multiplicities of spectral points of the conormal symbol (indicial family) and the integral from the Atiyah-Singer form over the smooth part of the manifold. The obtained formula is illustrated by the example of the Euler operator on a two-dimensional manifold with conical singular point.
The paper is an enquiry into dynamic social contract theory. The social contract defines the rules of resource use. An intergenerational social contract in an economy with a single exhaustible resource is examined within a framework of an overlapping generations model. It is assumed that new generations do not accept the old social contract, and access to resources will be renegotiated between any incumbent generation and their successors. It turns out that later generations will be in an unfortunate position regardless of their bargaining power.
Since the end of the year 1989 Liberia has been ravaged by a bloody civil war. It has almost completely destroyed the state structure of Liberian society which was manipulated by military ruler Samuel Doe and a small elite with the ends of amassing wealth and retaining power during the decade of 1980 to 1989. The state and almost all political institutions were stripped of credibility and legitimacy. During the war it was easy for the warlords of the various factions and their mostly young supporters to seize power and the remaining resources of the country. They established a radical free market system with the help of internationally operating companies and banks, protecting it by terror. Nearly two thirds of the population have left their homes and now live as refugees abroad, in the capital Monrovia or in Buchanan, where remnants of state structure and a weak civil society survive under the protection of a regional intervention army (Ecomog). By discussing different sociological explanations, the author traces the origins of the civil war and of its extreme brutality.