35 resultados para Predecessor Existence Problem
em Helda - Digital Repository of University of Helsinki
Resumo:
This thesis consists of three articles on passive vector fields in turbulence. The vector fields interact with a turbulent velocity field, which is described by the Kraichnan model. The effect of the Kraichnan model on the passive vectors is studied via an equation for the pair correlation function and its solutions. The first paper is concerned with the passive magnetohydrodynamic equations. Emphasis is placed on the so called "dynamo effect", which in the present context is understood as an unbounded growth of the pair correlation function. The exact analytical conditions for such growth are found in the cases of zero and infinite Prandtl numbers. The second paper contains an extensive study of a number of passive vector models. Emphasis is now on the properties of the (assumed) steady state, namely anomalous scaling, anisotropy and small and large scale behavior with different types of forcing or stirring. The third paper is in many ways a completion to the previous one in its study of the steady state existence problem. Conditions for the existence of the steady state are found in terms of the spatial roughness parameter of the turbulent velocity field.
Resumo:
In the last thirty years, primarily feminist scholars have drawn attention to and re-evaluated the philosophy of Simone de Beauvoir (1908 1986). Her philosophical practice has been described as non-systematic, and her literary writing has been viewed as part of her non-systematic mode of philosophising. This dissertation radically deepens the question concerning Beauvoir s philosophical motivations for turning to literature as a mode to express subjectivity. It explicates the central concepts of Beauvoir s philosophy of existence, which are subjectivity, ambiguity, paradox and temporality, and their background in the modern traditions of existential philosophy and phenomenology. It also clarifies Beauvoir s main reason to turn to literature in order to express subjectivity as both singular and universal: as a specific mode of communication, literature is able to make the universality of existence manifest in the concrete, singular and temporal texture of life. In addition, the thesis gives examples of how Beauvoir s literary works contribute to an understanding of the complexity of subjectivity. I use the expression poetics of subjectivity to refer to the systematic relation between Beauvoir s existential and phenomenological notion of subjectivity and her literary works, and to her articulations of a creative mode of using language, especially in the novel. The thesis is divided into five chapters, of which the first three investigate Beauvoir s philosophy of existence at the intersection of the modern traditions of thought that began with René Descartes and Søren Kierkegaard s intuitions about subjectivity. Chapter 1 interprets Beauvoir s notion of ambiguity, as compared to paradox, and argues that both determine her notion of existence. Chapters 2 and 3 investigate the phenomenological side of Beauvoir s philosophy through a study of her response to early French interpretations of transcendental subjectivity, especially in the works of Jean-Paul Sartre and Maurice Merleau-Ponty. My analysis shows that Edmund Husserl s distinction between different levels of subjective experience is central to Beauvoir s understanding of subjectivity and to the different ego concepts she uses. Chapter 4 is a study of Beauvoir s reflections on the expression of subjective thought, and, more specifically, her philosophical conceptions of the metaphysical novel and the autobiography as two modes of indirect communication. Chapter 5, finally, compares two modes of investigating concrete subjectivity; Beauvoir s conceptual study of femininity in Le deuxième sexe and her literary expression of subjectivity in the novel L Invitée. My analysis reveals and explicates Beauvoir s original contribution to a comprehensive understanding of the becoming and paradox of human existence: the fundamental insight that these phenomena are sexed, historically as well as imaginatively.
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The object of this dissertation is to study globally defined bounded p-harmonic functions on Cartan-Hadamard manifolds and Gromov hyperbolic metric measure spaces. Such functions are constructed by solving the so called Dirichlet problem at infinity. This problem is to find a p-harmonic function on the space that extends continuously to the boundary at inifinity and obtains given boundary values there. The dissertation consists of an overview and three published research articles. In the first article the Dirichlet problem at infinity is considered for more general A-harmonic functions on Cartan-Hadamard manifolds. In the special case of two dimensions the Dirichlet problem at infinity is solved by only assuming that the sectional curvature has a certain upper bound. A sharpness result is proved for this upper bound. In the second article the Dirichlet problem at infinity is solved for p-harmonic functions on Cartan-Hadamard manifolds under the assumption that the sectional curvature is bounded outside a compact set from above and from below by functions that depend on the distance to a fixed point. The curvature bounds allow examples of quadratic decay and examples of exponential growth. In the final article a generalization of the Dirichlet problem at infinity for p-harmonic functions is considered on Gromov hyperbolic metric measure spaces. Existence and uniqueness results are proved and Cartan-Hadamard manifolds are considered as an application.
Resumo:
Ingarden (1962, 1964) postulates that artworks exist in an “Objective purely intentional” way. According to this view, objectivity and subjectivity are opposed forms of existence, parallel to the opposition between realism and idealism. Using arguments of cognitive science, experimental psychology, and semiotics, this lecture proposes that, particularly in the aesthetic phenomena, realism and idealism are not pure oppositions; rather they are aspects of a single process of cognition in different strata. Furthermore, the concept of realism can be conceived as an empirical extreme of idealism, and the concept of idealism can be conceived as a pre-operative extreme of realism. Both kind of systems of knowledge are mutually associated by a synecdoche, performing major tasks of mental order and categorisation. This contribution suggests that the supposed opposition between objectivity and subjectivity, raises, first of all, a problem of translatability, more than a problem of existential categories. Synecdoche seems to be a very basic transaction of the mind, establishing ontologies (in the more Ingardean way of the term). Wegrzecki (1994, 220) defines ontology as “the central domain of philosophy to which other its parts directly or indirectly refer”. Thus, ontology operates within philosophy as the synecdoche does within language, pointing the sense of the general into the particular and/or viceversa. The many affinities and similarities between different sign systems, like those found across the interrelationships of the arts, are embedded into a transversal, synecdochic intersemiosis. An important question, from this view, is whether Ingardean’s pure objectivities lie basically on the impossibility of translation, therefore being absolute self-referential constructions. In such a case, it would be impossible to translate pure intentionality into something else, like acts or products.
Resumo:
The Lucianic text of the Septuagint of the Historical Books witnessed primarily by the manuscript group L (19, 82, 93, 108, and 127) consists of at least two strata: the recensional elements, which date back to about 300 C.E., and the substratum under these recensional elements, the proto-Lucianic text. Some distinctive readings in L seem to be supported by witnesses that antedate the supposed time of the recension. These witnesses include the biblical quotations of Josephus, Hippolytus, Irenaeus, Tertullian, and Cyprian, and the Old Latin translation of the Septuagint. It has also been posited that some Lucianic readings might go back to Hebrew readings that are not found in the Masoretic text but appear in the Qumran biblical texts. This phenomenon constitutes the proto-Lucianic problem. In chapter 1 the proto-Lucianic problem and its research history are introduced. Josephus references to 1 Samuel are analyzed in chapter 2. His agreements with L are few and are mostly only apparent or, at best, coincidental. In chapters 3 6 the quotations by four early Church Fathers are analyzed. Hippolytus Septuagint text is extremely hard to establish since his quotations from 1 Samuel have only been preserved in Armenian and Georgian translations. Most of the suggested agreements between Hippolytus and L are only apparent or coincidental. Irenaeus is the most trustworthy textual witness of the four early Church Fathers. His quotations from 1 Samuel agree with L several times against codex Vaticanus (B) and all or most of the other witnesses in preserving the original text. Tertullian and Cyprian agree with L in attesting some Hebraizing approximations that do not seem to be of Hexaplaric origin. The question is more likely of early Hebraizing readings of the same tradition as the kaige recension. In chapter 7 it is noted that Origen, although a pre-Lucianic Father, does not qualify as a proto-Lucianic witness. General observations about the Old Latin witnesses as well as an analysis of the manuscript La115 are given in chapter 8. In chapter 9 the theory of the proto-Lucianic recension is discussed. In order to demonstrate the existence of the proto-Lucianic recension one should find instances of indisputable agreement between the Qumran biblical manuscripts and L in readings that are secondary in Greek. No such case can be found in the Qumran material in 1 Samuel. In the text-historical conclusions (chapter 10) it is noted that of all the suggested proto-Lucianic agreements in 1 Samuel (about 75 plus 70 in La115) more than half are only apparent or, at best, coincidental. Of the indisputable agreements, however, 26 are agreements in the original reading. In about 20 instances the agreement is in a secondary reading. These agreements are early variants; mostly minor changes that happen all the time in the course of transmission. Four of the agreements, however, are in a pre-Hexaplaric Hebraizing approximation that has found its way independently into the pre-Lucianic witnesses and the Lucianic recension. The study aims at demonstrating the value of the Lucianic text as a textual witness: under the recensional layer(s) there is an ancient text that preserves very old, even original readings which have not been preserved in B and most of the other witnesses. The study also confirms the value of the early Church Fathers as textual witnesses.
Resumo:
DRAMATURGY OF THEATRE MANAGEMENT Essential tasks, everyday problems and the need for structural changes Theatre justifies its existence only through high quality performances. Maintaining the artistic level and organizing performances are the primary tasks of a manager, even though in everyday life this often seems to be overshadowed by all the other tasks of a manager s work. How does a theatre manager design strategies and make everyday decisions if aims are to have artistically meaningful performances, financial success and a socially healthy ensemble, when not only artistic work or leadership of an organization are to be taken into consideration, but also a manpower-based art institution with long traditions? What does theatre management consist of and what kind of dramaturgical movement happens in it? Based on interviews carried out in five different city theatres in Finland in the years 2004-2008, incident stories were written within a continuous comparison theory frame. Social constructionism within a dramaturgic framework enabled versatile dialog on a manager s work and problem areas. The result is an interpretative study, where instead of common regularities, many details are collected that can be taken into consideration when similar situations occur. Based on the interviews and historical data, four factors that influence a manager s work were chosen: ownership, media, work community and programme. Within theatre management, the central problems were 1) the inconsistent use of theatre resources and problems in corporate governance caused by the administrative models; 2) the theatre s image, based on the image of its manager, as presented by the media and its influence on the wellbeing of the staff; 3) unsolved problems between the staff left behind by the previous managers and problems related to casting; 4) knowledge of the audience. These points influence how the manager plans the artistic programme and divides the resources. The theatre manager s job description has remained quite the same since the early days of Kaarlo Bergbom. In the future, special attention should be placed on why managers face fairly similar problems decade after decade. Reducing these problems partly depends on whether structural improvements are made to a theatre s close network of owners, financers and labour unions. During this study clear evidence was seen that structural changes are necessary in the production of performances and in the creation of a more versatile programme. In this process, different kinds of co-operation, experiments, development projects, continuing education and international relations have special importance, especially if the aim is to make it possible for all citizens of Finland to enjoy a vibrant and revitalized theatre.
Resumo:
In this study I consider what kind of perspective on the mind body problem is taken and can be taken by a philosophical position called non-reductive physicalism. Many positions fall under this label. The form of non-reductive physicalism which I discuss is in essential respects the position taken by Donald Davidson (1917-2003) and Georg Henrik von Wright (1916-2003). I defend their positions and discuss the unrecognized similarities between their views. Non-reductive physicalism combines two theses: (a) Everything that exists is physical; (b) Mental phenomena cannot be reduced to the states of the brain. This means that according to non-reductive physicalism the mental aspect of humans (be it a soul, mind, or spirit) is an irreducible part of the human condition. Also Davidson and von Wright claim that, in some important sense, the mental aspect of a human being does not reduce to the physical aspect, that there is a gap between these aspects that cannot be closed. I claim that their arguments for this conclusion are convincing. I also argue that whereas von Wright and Davidson give interesting arguments for the irreducibility of the mental, their physicalism is unwarranted. These philosophers do not give good reasons for believing that reality is thoroughly physical. Notwithstanding the materialistic consensus in the contemporary philosophy of mind the ontology of mind is still an uncharted territory where real breakthroughs are not to be expected until a radically new ontological position is developed. The third main claim of this work is that the problem of mental causation cannot be solved from the Davidsonian - von Wrightian perspective. The problem of mental causation is the problem of how mental phenomena like beliefs can cause physical movements of the body. As I see it, the essential point of non-reductive physicalism - the irreducibility of the mental - and the problem of mental causation are closely related. If mental phenomena do not reduce to causally effective states of the brain, then what justifies the belief that mental phenomena have causal powers? If mental causes do not reduce to physical causes, then how to tell when - or whether - the mental causes in terms of which human actions are explained are actually effective? I argue that this - how to decide when mental causes really are effective - is the real problem of mental causation. The motivation to explore and defend a non-reductive position stems from the belief that reductive physicalism leads to serious ethical problems. My claim is that Davidson's and von Wright's ultimate reason to defend a non-reductive view comes back to their belief that a reductive understanding of human nature would be a narrow and possibly harmful perspective. The final conclusion of my thesis is that von Wright's and Davidson's positions provide a starting point from which the current scientistic philosophy of mind can be critically further explored in the future.
Resumo:
Jakke Holvas: A Critique of the Metaphysics of Economy The research problem of this dissertation is the commonly held opinion according to which everything has become a question of economy in the present day. Economy legitimates and justifies. In this study, the pattern of thinking and conceptualizing in which economy figures as the ultimate reason is called the metaphysics of economy. The defining characteristic of the metaphysics of economy is its failure to recognize non-economic rules, ethics, or ways of existence. The sources included in the study cover certain classics of philosophy (Plato, Aristotle, Friedrich Nietzsche) and sociology (Karl Marx, Max Weber, Marcel Mauss), as well as the more recent French social theory (Jean Baudrillard, Michel Foucault). The research methods used are textual analysis and evaluation of concepts by means of historical comparison. The background to the study is given by the views of historians and sociologists according to whom traditional forms have ceased to exist and the market economy become established as the western system of values. The study identifies points of transition from the traditional forms to economic values. In addition, the dissertation focuses on the modern non-economic forms. The study examines the economic and ethical meanings of gift in antiquity in Homer, Plato, and Aristotle. Following Marcel Mauss, the study analyzes the forms and principles of gift exchange. The study also applies Nietzsche’s philosophy to evaluate under what conditions giving a gift becomes an act of exercising power that puts its receiver into debt. The conclusion of the study is that the classics of philosophy and sociology can rightly be interpreted in terms of the metaphysics of economy, but they also offer grounds for criticizing this metaphysics, even alternatives. One such alternative is non-economic archaic ethic. The study delineates a duality between economy and non-economy as well as creating concepts which could be used in the future to critically analyze economy from a position external to the economic system of concepts.
Resumo:
Design embraces several disciplines dedicated to the production of artifacts and services. These disciplines are quite independent and only recently has psychological interest focused on them. Nowadays, the psychological theories of design, also called design cognition literature, describe the design process from the information processing viewpoint. These models co-exist with the normative standards of how designs should be crafted. In many places there are concrete discrepancies between these two in a way that resembles the differences between the actual and ideal decision-making. This study aimed to explore the possible difference related to problem decomposition. Decomposition is a standard component of human problem-solving models and is also included in the normative models of design. The idea of decomposition is to focus on a single aspect of the problem at a time. Despite its significance, the nature of decomposition in conceptual design is poorly understood and has only been preliminary investigated. This study addressed the status of decomposition in conceptual design of products using protocol analysis. Previous empirical investigations have argued that there are implicit and explicit decomposition, but have not provided a theoretical basis for these two. Therefore, the current research began by reviewing the problem solving and design literature and then composing a cognitive model of the solution search of conceptual design. The result is a synthetic view which describes recognition and decomposition as the basic schemata for conceptual design. A psychological experiment was conducted to explore decomposition. In the test, sixteen (N=16) senior students of mechanical engineering created concepts for two alternative tasks. The concurrent think-aloud method and protocol analysis were used to study decomposition. The results showed that despite the emphasis on decomposition in the formal education, only few designers (N=3) used decomposition explicitly and spontaneously in the presented tasks, although the designers in general applied a top-down control strategy. Instead, inferring from the use of structured strategies, the designers always relied on implicit decomposition. These results confirm the initial observations found in the literature, but they also suggest that decomposition should be investigated further. In the future, the benefits and possibilities of explicit decomposition should be considered along with the cognitive mechanisms behind decomposition. After that, the current results could be reinterpreted.
Resumo:
The thesis aims to link the biolinguistic research program and the results of studies in comceptual combination from cognitive psychology. The thesis derives a theory of syntactic structure of noun and adjectival compounds from the Empty Lexicon Hypothesis. Two compound-forming operations are described: root-compounding and word-compounding. The aptness of theory is tested with finnish and greek compounds. From the syntactic theory semantic requirements for conceptual system are derived, especially requirements for handling morphosyntactic features. These requirements are compared to three formidable theories of conceptual combination: relation theory CARIN, Dual-Process theory and C3-theory. The claims of explanatory power of relational distributions of modifier in CARIN-theory ared discarded, as the method for sampling and building relational distributions is not reliable and the algorithmic instantiation of theory does not compute what it claims to compute. From relational theory there still remains results supporting existence of 'easy' relations for certain concepts. Dual-Process theory is found to provide results that cannot in theory be affected by linguistic system, but the basic idea of property compounds is kept. C3-theory is found to be not computationally realistic, but the basic results of diagnosticity and local properties (domains) of conceptual system are solid. The three conceptual combination models are rethought as a problem of finding the shortest route between the two concepts. The new basis for modeling is suggested to be bare conceptual landscape with morphosyntactiic or semantic features working as guidance and structural features of landscape basically unknown, but such as they react to features from linguistic system. Minimalistic principles to conceptual modeling are suggested.
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One of the unanswered questions of modern cosmology is the issue of baryogenesis. Why does the universe contain a huge amount of baryons but no antibaryons? What kind of a mechanism can produce this kind of an asymmetry? One theory to explain this problem is leptogenesis. In the theory right-handed neutrinos with heavy Majorana masses are added to the standard model. This addition introduces explicit lepton number violation to the theory. Instead of producing the baryon asymmetry directly, these heavy neutrinos decay in the early universe. If these decays are CP-violating, then they produce lepton number. This lepton number is then partially converted to baryon number by the electroweak sphaleron process. In this work we start by reviewing the current observational data on the amount of baryons in the universe. We also introduce Sakharov's conditions, which are the necessary criteria for any theory of baryogenesis. We review the current data on neutrino oscillation, and explain why this requires the existence of neutrino mass. We introduce the different kinds of mass terms which can be added for neutrinos, and explain how the see-saw mechanism naturally explains the observed mass scales for neutrinos motivating the addition of the Majorana mass term. After introducing leptogenesis qualitatively, we derive the Boltzmann equations governing leptogenesis, and give analytical approximations for them. Finally we review the numerical solutions for these equations, demonstrating the capability of leptogenesis to explain the observed baryon asymmetry. In the appendix simple Feynman rules are given for theories with interactions between both Dirac- and Majorana-fermions and these are applied at the tree level to calculate the parameters relevant for the theory.
Resumo:
The problem of recovering information from measurement data has already been studied for a long time. In the beginning, the methods were mostly empirical, but already towards the end of the sixties Backus and Gilbert started the development of mathematical methods for the interpretation of geophysical data. The problem of recovering information about a physical phenomenon from measurement data is an inverse problem. Throughout this work, the statistical inversion method is used to obtain a solution. Assuming that the measurement vector is a realization of fractional Brownian motion, the goal is to retrieve the amplitude and the Hurst parameter. We prove that under some conditions, the solution of the discretized problem coincides with the solution of the corresponding continuous problem as the number of observations tends to infinity. The measurement data is usually noisy, and we assume the data to be the sum of two vectors: the trend and the noise. Both vectors are supposed to be realizations of fractional Brownian motions, and the goal is to retrieve their parameters using the statistical inversion method. We prove a partial uniqueness of the solution. Moreover, with the support of numerical simulations, we show that in certain cases the solution is reliable and the reconstruction of the trend vector is quite accurate.
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The topic of this dissertation is the geometric and isometric theory of Banach spaces. This work is motivated by the known Banach-Mazur rotation problem, which asks whether each transitive separable Banach space is isometrically a Hilbert space. A Banach space X is said to be transitive if the isometry group of X acts transitively on the unit sphere of X. In fact, some weaker symmetry conditions than transitivity are studied in the dissertation. One such condition is an almost isometric version of transitivity. Another investigated condition is convex-transitivity, which requires that the closed convex hull of the orbit of any point of the unit sphere under the rotation group is the whole unit ball. Following the tradition developed around the rotation problem, some contemporary problems are studied. Namely, we attempt to characterize Hilbert spaces by using convex-transitivity together with the existence of a 1-dimensional bicontractive projection on the space, and some mild geometric assumptions. The convex-transitivity of some vector-valued function spaces is studied as well. The thesis also touches convex-transitivity of Banach lattices and resembling geometric cases.
Resumo:
In this thesis we study a series of multi-user resource-sharing problems for the Internet, which involve distribution of a common resource among participants of multi-user systems (servers or networks). We study concurrently accessible resources, which for end-users may be exclusively accessible or non-exclusively. For all kinds we suggest a separate algorithm or a modification of common reputation scheme. Every algorithm or method is studied from different perspectives: optimality of protocols, selfishness of end users, fairness of the protocol for end users. On the one hand the multifaceted analysis allows us to select the most suited protocols among a set of various available ones based on trade-offs of optima criteria. On the other hand, the future Internet predictions dictate new rules for the optimality we should take into account and new properties of the networks that cannot be neglected anymore. In this thesis we have studied new protocols for such resource-sharing problems as the backoff protocol, defense mechanisms against Denial-of-Service, fairness and confidentiality for users in overlay networks. For backoff protocol we present analysis of a general backoff scheme, where an optimization is applied to a general-view backoff function. It leads to an optimality condition for backoff protocols in both slot times and continuous time models. Additionally we present an extension for the backoff scheme in order to achieve fairness for the participants in an unfair environment, such as wireless signal strengths. Finally, for the backoff algorithm we suggest a reputation scheme that deals with misbehaving nodes. For the next problem -- denial-of-service attacks, we suggest two schemes that deal with the malicious behavior for two conditions: forged identities and unspoofed identities. For the first one we suggest a novel most-knocked-first-served algorithm, while for the latter we apply a reputation mechanism in order to restrict resource access for misbehaving nodes. Finally, we study the reputation scheme for the overlays and peer-to-peer networks, where resource is not placed on a common station, but spread across the network. The theoretical analysis suggests what behavior will be selected by the end station under such a reputation mechanism.