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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
241

A Survey On Known Algorithms In Solving Generalizationbirthday Problem (k-list)

Namaziesfanjani, Mina 01 February 2013 (has links) (PDF)
A well known birthday paradox is one the most important problems in cryptographic applications. Incremental hash functions or digital signatures in public key cryptography and low-weight parity check equations of LFSRs in stream ciphers are examples of such applications which benet from birthday problem theories to run their attacks. Wagner introduced and formulated the k-dimensional birthday problem and proposed an algorithm to solve the problem in O(k.m^ 1/log k ). The generalized birthday solutions used in some applications to break Knapsack based systems or collision nding in hash functions. The optimized birthday algorithms can solve Knapsack problems of dimension n which is believed to be NP-hard. Its equivalent problem is Subset Sum Problem nds the solution over Z/mZ. The main property for the classication of the problem is density. When density is small enough the problem reduces to shortest lattice vector problem and has a solution in polynomial time. Assigning a variable to each element of the lists, decoding them into a matrix and considering each row of the matrix as an equation lead us to have a multivariate polynomial system of equations and all solution of this type can be a solution for the k- list problem such as F4, F5, another strategy called eXtended Linearization (XL) and sl. We discuss the new approaches and methods proposed to reduce the complexity of the algorithms. For particular cases in over-determined systems, more equations than variables, regarding to have a single solutions Wolf and Thomea work to make a gradual decrease in the complexity of F5. Moreover, his group try to solve the problem by monomials of special degrees and linear equations for small lists. We observe and compare all suggested methods in this
242

Sweden´s Affinity towards Czech Republic : - A Gravity Model Approach

Olsson, Agneta January 2011 (has links)
Abstract It is well known that geographical distances between nations cause differences in cul-tural resemblances as well as affinity. Defined, affinity is inheriting similarities between nations in familiarity, language and mutual understanding. It cause variations in the uni-lateral trade volume flowing towards the destination countries and can be estimated by a traditional gravity model (GM). So far Swedish affinity towards Czech Republic (CZ) has remained unexplored. Hence, this paper investigates Swedish firm´s export perfor-mance and affinity towards CZ, both through the aggregate export and the extensive margin (average number of exporters). The investigation aims to seek clarification of what particular factors influence unilateral export towards CZ as well as stronger affini-ty in contrast to similar markets. To answer those questions, a one sided GM is re-gressed on two gravity equations, covering panel data for 177 destination countries from year 1997 to 2006. Results are in line with the expected behavior of the GM and show evidently; distance as well as land lock features have negative effects on unilateral ex-ports to CZ. Additionally, evidence of positive influence on unilateral export is found for GDP and familiarity to the nation. Both regressions for the gravity equations are showing high goodness of fit for the panel data. Findings of positive residuals in both the equations conclude that Swedish export have stronger affinity to CZ and solider country characteristics than its resembling countries Slovenia and Slovakia. However, positive residuals also indicate larger export flows to CZ than motivated by the tradi-tional GM coefficients. Various explanations are suggested as origins for those, such as differences in purchasing power and regions, were Prague was found to be the most suitable option for export and other regions rather for outsourcing possibilities.
243

Balancing the Paradox of Localization and Globalization : Research and Analyze the Levels of Market Involvement for Multinational Carmakers in China's Market

Chen, Jun, Jiao, Zhiqiang January 2008 (has links)
Multinational Corporations (MNCs) are facing the paradox of globalization and localization in entering each new market. Generally, there are two perspectives which regard to how a MNC configure its cross-border activities: The first is global convergence perspective, which focuses on leveraging corporate resources and attaining global synergies. The second is international diversity perspective, which lays more emphasis on local adaptation and harnessing diversities. Both perspectives have their pros and cons, a balance between international standardization and local adaptation is vital. For the major Auto Giants in the world operating and competing worldwide, the significance of China market is as clear as day to everyone. This paper focuses on how the major Auto Giants balance the paradox of globalization and localization in the China market. In other words, how the MNCs deal with the dilemma of globalization and localization under different strategic contexts? We adopt a model which divides their activities in China into 6 stages and which includes criteria with regard to the dilemma of localization and globalization.
244

Some Set-theoretical Traces In Leibniz&#039 / s Works.

Ertemiz, Nusret 01 January 2011 (has links) (PDF)
The purpose of this dissertation is to search the primitives of Axiomatic Set Theory in Leibnizian Philolosophy, nourishing, roughly, from Platonic idea of universal-particular distinction, Aristotelian syllogistic propositions of Organon-Categoria and Euclidean Methodology in Elements. The main focus of the dissertation intends to examine the analyticity of Leibnizian Metaphysics and the anologies between the subject-predicate relation in The Philosophy of Leibniz and Axiomatic Method in general and Set Theory in particular. In doing this, special emphasis will be ascribed to the notion of sets as to universality and/or nullness of a class, probable causes of paradoxes and in this context a critical analysis of Russell Paradox.
245

The Visibility and Invisibility in Legal Phenomenon:the Limitation of Language as Point of Departure

Wu, Jie-ren 14 May 2009 (has links)
none
246

Glycodelin A : A Novel Immunoregulatory Lectin Of The Female Reproductive Tract : Molecular Mechanism Of GdA-Induced Apoptosis In Activated T Cells

Sundarraj, Swathi 04 1900 (has links)
Glycodelin is a 162 amino acid secreted glycoprotein classified as a member of the lipocalin (carriers of small hydrophobic molecules) superfamily based on the presence of lipocalin signature motifs in its primary sequence. The protein has several isoforms which are expressed by various primate tissues, predominantly reproductive tissues. These isoforms are products of the same gene and hence have the same primary sequence; however, they are differentially glycosylated depending on tissue origin. The individual glycodelin isoforms perform very varied functions, which are largely dictated or modulated by the specific glycans on the molecule. Glycodelin A (GdA) is the major glycodelin isoform of the female reproductive tract; and is subclassified as an immunocalin (lipocalins with immunological function) due to its ability to modulate immune responses. Diverse activities have been associated with GdA; pertaining to determination of cell fate, tissue differentiation and significantly, immunomodulation towards fetal-allograft tolerance. The fetus expresses paternal allo-antigens and would be regarded as non-self or foreign by the maternal immune system. However, several synergistic mechanisms of immunomodulation at the fetal-maternal interface establish tolerance towards fetal antigens, protecting it from rejection. GdA is secreted by the uterine endometrium under progesterone induction, and is therefore the most abundant progesterone-regulated secretory glycoprotein of the uterus at the time of implantation and early pregnancy. GdA has been shown to have immunomodulatory activity targeting innate, humoral and cellular responses. It is inhibitory to T cell and B cell proliferation, and NK cell activity. It stimulates the Th2-type cytokine profile, and inhibits interleukins IL-2 and IL-1 production from mitogenically stimulated lymphocytes and mononuclear cell cultures. It has been reported from our laboratory that GdA induces apoptosis in activated T cells. GdA has also been shown to be inhibitory to B cells and monocytes. Clinical studies correlate subnormal levels of GdA with implantation Synopsis failure, habitual abortion and recurrent miscarriage. Due to its pleiotropic nature namely its diverse activities on different immune cell types; its spatio-temporal restriction of expression by progesterone; and its indispensable requirement for successful pregnancy; GdA is being increasingly recognized as a mechanism towards fetal allograft tolerance. Our laboratory has focused on the T cell inhibitory activity of GdA, with particular emphasis on T cell apoptosis. This study was aimed at delineating the molecular mechanism of GdA-induced apoptosis in activated T cells. Previous results from our laboratory have revealed that GdA-induced apoptosis is caspase dependent; and is not initiated by the extrinsic pathway involving Fas/death receptor signailing or initiator caspase 8. In this thesis, we present evidence that GdA triggers the intrinsic apoptotic program in T cells. Characterization of the apoptotic program initiated by GdA is presented in Chapter 1. We observe that GdA treatment triggers a stress response leading to decrease in mitochondrial transmembrane potential, which indicates mitochondrial membrane permeabilization (MMP). GdA-induced apoptosis can also be blocked by inhibition of caspase 9, the initiator caspase for the intrinsic program. The kinetics of mitochondrial depolarization precede onset of DNA fragmentation in both peripheral blood T cells and Jurkat cells treated with GdA. We also observe caspase 2 activation downstream of the mitochondria. Overexpression of the antiapoptotic protein Bcl-2 is sufficient to protect from GdA-induced cellular stress indicating that the apoptotic program can be reversed upstream of the mitochondria. Further, our studies reveal that stress signaling by GdA is not mediated by any of the canonical second messengers of stress signaling, namely, reactive oxygen species; the stress activated protein kinases JNK, p38 MAPK and ERK; intracellular calcium or ceramide. It has been reported that GdA desensitizes T cell receptor (TCR) signaling by decreasing the stability of TCR-triggered phosphoproteins, probably by its association ith the transmembrane tyrosine phosphatase CD45. TCR-desensitization would result in decreased proliferation and cytokine secretion, and has been postulated as the mechanism of T cell-inhibition by GdA. We have tested this theory and Chapter 2 provides evidence that the apoptogenic activity of GdA is not a consequence of its ability to blunt TCR-signaling. Further, GdA-induced apoptosis does not depend on components of the TCR signal cascade namely CD45, the kinase Lck and CTLA4, molecules that are proven transducers of apoptotic signals to the mitochondria in response to diverse stress stimuli. GdA triggers apoptosis in the CD45 deficient cell line J45.01 with similar kinetics of MMP and DNA fragmentation as with Synopsis wildtype cells, demonstrating that CD45 is not the determinant receptor for apoptosis on cells. We also observe that GdA is inhibitory to T cells stimulated with phorbol ester and calcium ionophore, which bypasses TCR-proximal signaling events; and that GdA treatment does not interfere with early T cell activation as evidenced from induction of the activation marker CD69. Thus, GdA initiates mitochondrial stress mediated apoptosis in T cells by a pathway that is distinct and independent from the TCR-coupled signaling pathway. This study presents a novel mode of immunosuppression for GdA and highlights the ability of GdA to suppress the immune response by more than one mechanism. Cell surface glycoproteins undergo alterations in their carbohydrate profiles upon T cell activation and differentiation, and this has a significant role to play in lymphocyte fate and function. One such global alteration in cell surface glycans is a difference in sialylation upon T cell activation and differentiation. While activated T cell have a lesser degree of sialylated surface glycoproteins as compared to naïve T cells, memory T cells are sialylated to a higher extent, and Th2 cells have more cell surface sialic acids than Th1 cells. As GdA is capable of triggering apoptosis in activated T cells, we investigated the requirement of cell surface glycans for differential recognition of T cell subsets by GdA, the results for which are detailed in Chapter 3. We observe that the activity of GdA could be competed out by asialofetuin and not fetuin, suggesting that GdA recognizes terminal galactose residues on asialofetuin glycans, which would be masked by sialic acids in case of fetuin glycans. This assumption was confirmed as the free sugars lactose and galactose, but not annose, could also competitively inhibit GdA activity. We also demonstrate that the lectin-activity of dA is calcium independent, typical of mammalian galectins. Thus, our results reveal GdA to be a novel galactose-specific lectin of the female reproductive tract. This carbohydrate specificity of GdA is responsible for its apoptotic activity on T cells. The selectivity of GdA towards activated T cells is a result of increased exposure of terminal galactose residues on activated T cell surface receptors, as demonstrated by staining of naïve and stimulated T cells with Fluorescent lectin-conjugates of different carbohydrate specificities. We also demonstrate hat GdA shows specificity towards N-liked glycans on cell surface glycoproteins. This is evident from the use of glycan processing inhibitors, which prevent addition of galactose to the core glycan on the nascent polypeptide chain. We observe that inhibition of processing of N-glycans, and not O-glycans, render cells resistant to GdA. Incidentally, we observe that another property of GdA, namely its ability to induce Synopsis epithelial differentiation and apoptosis in the breast cancer cell line MCF-7, is also due to ts galactose-specific lectin activity. It is therefore probable that the diverse functions ssociated with GdA are a consequence of its ability to recognize different glycoprotein receptors on different cell types. We can thus draw a comparison for GdA with the galectins, which are the prototype beta-galactoside binding mammalian lectins with diverse roles in determining cell fate and apoptosis, especially in the immune system. In fact, the immune-related activities of GdA are almost identical to the effects of galectin-1 on the immune system. Galectin-1 has also very recently been shown to play a significant role in fetal-tolerance. This raises a strong possibility of shared receptors for GdA and galectin-1 on the T cell surface, resulting from a shared calcium-independent recognition property for complex glycans with terminal galactose residues. Two predominant galectin-1 receptors on T cells are the glycoproteins CD45 and CD7. We have already observed that though GdA may recognize CD45, this association does not mediate its apoptotic activity. We therefore examined the possibility of the activation-induced glycoprotein CD7 as receptor for GdA. Our experiments reveal that the apoptotic activity of GdA on different T cell lines is dependent on the degree of CD7 expression by these cell lines. Notably, the CD7 negative lymphoma cell line HuT78 was completely resistant to GdA. To confirm CD7 as receptor, we obtained a cell line HuT78.7 in which CD7 expression has been restored by stable transfection. We observed that these CD7 positive cells now responded to GdA comparable to Jurkat cells, and GdA-induced apoptosis in these cells could be completely competed out with asialofetuin, not fetuin. To summarize, our study identifies GdA as a novel pregnancy-related galectin-like lectin of the female reproductive tract, which triggers mitochondrial stress and apoptosis in activated T cells. GdA shares receptors on T cells with galectin-1 due a common carbohydrate recognition property. We identify CD7 as a molecular target for GdA on activated T cells, capable of mediating the apoptotic signal. However, it is likely that GdA also recognizes other galectin receptors on T cells, as it is capable of inhibition by more than one mechanism. This underscores the requirement for redundant mechanisms indispensable for establishment and maintenance of successful pregnancy.
247

The Normativity of Thought and Meaning

Karlander, Karl January 2008 (has links)
In recent years the normativity of thought and meaning has been the subject of an extensive debate. What is at issue is whether intentionality has normative features, and if so, whether that constitutes a problem for naturalistic attempts to account for intentional phenomena. The origin of the debate is Saul Kripke’s interpretation of Ludwig Wittgenstein’s later philosophy, published in Wittgenstein on Rules and Private Language. Kripke claimed, on behalf of Wittgenstein, that dispositional accounts of linguistic meaning - accounts, i.e., which attempt to reduce semantic phenomena to facts about how speakers are disposed to employ words - fail to ground the factuality of semantic statements. From this, and other arguments, the far reaching conclusion was drawn by Kripke’s Wittgenstein that there are no semantic facts, that every application of a word is “a leap in the dark”. This position has become known as meaning scepticism. In the present essay, it will be argued that meaning scepticism is incoherent, but that the normativity argument is interesting in its own right. The development of the debate will be traced, primarily through detailed consideration of the writings of Paul Boghossian, who has shifted the focus from the normativity of linguistic meaning to that of belief. It will be contended that even though Boghossian’s attempt to locate a normativity of belief fails, there is a related form of normativity that has to do with the intrinsic badness of false beliefs. Also, suggestions made by Kripke regarding the normativity of intentions will be investigated, and related to contemporary arguments in the philosophy of rationality. The tentative conclusion is that there are some interesting kinds of normativity associated with the intentional, but of a somewhat different variety than those usually discussed.
248

Privacy paradox or bargained-for-exchange : capturing the relationships among privacy concerns, privacy management, self-disclosure, and social capital

Hsu, Shih-Hsien 16 January 2015 (has links)
The dissertation seeks to bridge the gap between privacy and social capital on SNS use by bringing the essential elements of social networking, privacy concerns, privacy management, self-disclosure, and social capital together to examine their complex relationships and the daily challenges every SNS user faces. The major purposes of this dissertation were to revisit the privacy paradox phenomenon, update the current relationships among privacy concerns, self-disclosure, and social capital on Facebook, integrate these relationships into a quantitative model, and explore the role of privacy management in these relationships. The goal was realized by using Amazon.com’s Mechanical Turk to test a theoretical model that used survey data from 522 respondents. The findings from the dissertation show the impact of the structural factor—Facebook social network intensity and diversity—and the impact of individuals’ self-disclosure on Facebook on their perceived bridging and bonding social capital. This dissertation employed various measurements of key variables to update the current status of the privacy paradox phenomenon—the disconnection between privacy concerns and self- disclosure on social media—and found the break of the traditional privacy paradox and the existence of the social privacy paradox. Findings also show that private information about personal information, thoughts, and ideas shared on Facebook become assets in using Facebook and accumulating social capital. Meanwhile, higher privacy concerns reduce the level of self-disclosure on Facebook. Therefore, privacy concerns become a barrier in Facebook use and in accumulating social capital within these networks. This dissertation further examined the mediating role of privacy management to solve the dilemma. Findings confirmed that privacy management is important in redirecting the relationships among privacy concerns, self-disclosure, and social capital. People who have higher privacy concerns tend to disclose fewer personal thoughts and ideas on Facebook and miss the opportunity to accumulate social capital. However, when they employ more privacy management strategies, they are more willing to self-disclose and thus accumulate more social capital on Facebook networks. Lastly, the proposed integrated model examined through SEM analysis confirms the delicate relationships among the social networking characteristics, privacy concerns, privacy management, self-disclosure, and social capital. / text
249

'Making People Happy, Not Making Happy People': A Defense of the Asymmetry Intuition in Population Ethics

Frick, Johann David 21 October 2014 (has links)
This dissertation provides a defense of the normative intuition known as the Procreation Asymmetry, according to which there is a strong moral reason not to create a life that will foreseeably not be worth living, but there is no moral reason to create a life just because it would foreseeably be worth living. Chapter 1 investigates how to reconcile the Procreation Asymmetry with our intuitions about another recalcitrant problem case in population ethics: Derek Parfit's Non-Identity Problem. I show that what has prevented philosophers from developing a theory that gives a satisfactory account of both these problems is their tacit commitment to a teleological conception of well-being, as something to be `promoted'. Replacing this picture with one according to which our reasons to confer well-being on people are conditional on their existence allows me to do better. It also enables us to understand some of the deep structural parallels between seemingly disparate normative phenomena such as procreating and promising. Chapter 2 attempts to connect my defense of the Procreation Asymmetry to corresponding evaluative claims about the goodness of the outcomes produced by procreative decisions. I propose a view, the `biconditional buck-passing view of outcome betterness', according to which facts about the comparative goodness of outcomes are a function of our reasons for bringing about one outcome rather than another under certain conditions. This enables me to derive an Evaluative Procreation Asymmetry from the corresponding normative claims established in Chapter 1. The biconditional buck-passing view also provides me with a principled basis for challenging a version of the Independence of Irrelevant Alternatives Principle. This, in turn, permits me to provide a novel solution to another famous problem in population ethics: Parfit's Mere Addition Paradox. Finally, in Chapter 3, I rebut some key objections to the Procreation Asymmetry by showing that upholding it does not commit us to anti-natalism and that it is compatible with a moral concern for the long-term survival of humanity. / Philosophy
250

AdS/CFT, Black Holes, And Fuzzballs

Zadeh, Aida 09 January 2014 (has links)
In this thesis we investigate two different aspects of the AdS/CFT correspondence. We first investigate the holographic AdS/CMT correspondence. Gravitational backgrounds in d+2 dimensions have been proposed as holographic duals to Lifshitz-like theories describing critical phenomena in d+1 dimensions with critical exponent z>1. We numerically explore a dilaton-Einstein-Maxwell model admitting such backgrounds as solutions. We show how to embed these solutions into AdS space for a range of values of z and d. We next investigate the AdS3/CFT2 correspondence and focus on the microscopic CFT description of the D1-D5 system on T^4*S_1. In the context of the fuzzball programme, we investigate deforming the CFT away from the orbifold point and study lifting of the low-lying string states. We start by considering general 2D orbifold CFTs of the form M^N/S_N, with M a target space manifold and S_N the symmetric group. The Lunin-Mathur covering space technique provides a way to compute correlators in these orbifold theories, and we generalize this technique in two ways. First, we consider excitations of twist operators by modes of fields that are not twisted by that operator, and show how to account for these excitations when computing correlation functions in the covering space. Second, we consider non-twist sector operators and show how to include the effects of these insertions in the covering space. Using the generalization of the Lunin-Mathur symmetric orbifold technology and conformal perturbation theory, we initiate a program to compute the anomalous dimensions of low-lying string states in the D1-D5 superconformal field theory. Our method entails finding four-point functions involving a string operator O of interest and the deformation operator, taking coincidence limits to identify which other operators mix with O, subtracting conformal families of these operators, and computing their mixing coefficients. We find evidence of operator mixing at first order in the deformation parameter, which means that the string state acquires an anomalous dimension. After diagonalization this will mean that anomalous dimensions of some string states in the D1-D5 SCFT must decrease away from the orbifold point while others increase. Finally, we summarize our results and discuss some future directions of research.

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