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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.
81

Convergence Analysis of BAM on Laplace BVP with Singularities

Wang, Jau-Ren 17 July 2006 (has links)
The particular solutions of the Laplace equations and their singularities are fundamental to numerical partial di erential equations in both algorithms and error analysis. We first review the explicit solutions of Laplace¡¦s equations on sectors with the Dirichlet and the Neumann boundary conditions. These harmonic functions clearly expose the solution¡¦s regularity/singularity at the vertex. So we can analyze the singularity of the Laplace¡¦s solutions on polygons at di erent domain corners and for various boundary conditions. By using this knowledge we can designed many new testing models with di erent kind of singularities, like discontinuous and mild singularities, beside the popular singularity models, Motz¡¦s and the cracked beam problems, We use the boundary approximation method, i.e. the collocation Tre tz method in engineering literatures, to solve the above testing models of Laplace boundary value problems on polygons. Suppose the uniform particular solutions are chosen in the entire domain. When there is no singularity on all corners, this method has the exponential convergence. However, its rate of convergence will deteriorate to polynomial if there exist some corner singularities. From experimental data, we even have three type of convergence, i.e. exponential, polynomial or their mixed types. We will study these convergent behaviors and their causes. Finally, we will uncover the relation between the order of convergence and the intensity of corner singularities.
82

A Study of Internet User's Acceptance on Voice Over Internet Protocol

Wang, Cheng-chin 20 June 2007 (has links)
The rapid development of the Internet and Wireless Local Area Network cause VoIP plays an important role among the emerging communication products. The purpose of this study is to explore the VoIP acceptance of the Internet user from the model of the Unified Theory of Acceptance and Use of Technology (UTAUT). This study designed a questionnaire that regarded with the degree of the acceptance of VoIP according to the review of the literatures. After the research, this study indicates that there are three components that influenced the degree of acceptance of VoIP include perceived easy of use, performance expectancy and social influence and different factors under different demography significantly influence the intention of the user. Related to these three components, this study first indicates that sex has a significant influence in the expectation of the achievement and the result shows that male is more significant than female. Second, age has no significant influence. Third, different education level has significant influence in the component of perceived easy of use, especially the user who has Master and PHD degree is more significant than the user only has graduated degree. Forth, different using experience and Voluntariness of Use have different significant influence among these three components.
83

A Study on the Regulation for Convergence of Telecommunication and Cable TV Industries -Sampling European Union

Lin, Jia-Hung 12 June 2001 (has links)
THESIS ABSTRACT A Study on the Regulation for Convergence of Telecommunication and Cable TV Industries -Sampling European Union Audio, video and data are transferred by different channels traditionally. Therefore, there are diverse industries such as telecommunications, cable TV etc. But now the boundary between industries is ambiguous which is affected by technology development. This phenomenon makes it possible that competition exists between different industries. Moreover, it enhances the opportunities of convergence of industries and operation across industries. However conventional regulation defines regulatory scope according to products, services or technology. But changes of technology and market make conventional regulation unsuitable to current environment. Hence we should take a new regulation framework adapted to new market and development. European Union had involved these issues since 1980s and submitted a regulation framework suitable for future situation. Therefore, the researcher describes the roles and functions of relating authorities of E.U. and demonstrates the concrete implementations in response to convergence. Afterward, the researcher analyzes E.U. regulation by two perspectives: regulation authorities and regulation measures. From regulation authority perspective, the roles and attitudes about operation process are observed. From regulation measure perspective, these measures will be analyzed by goal, type and strategic level. Finally, the researcher tries to search for a general regulation framework for Taiwan¡¦s reference. In addition, after Taiwan¡¦s entrance to WTO, the process of negotiation between countries of E.U. could be a reference for Taiwan¡¦s authority to deal with international affairs.
84

On the Study of Efficient Metaheuristics via Pattern Reduction

Tsai, Chun-Wei 05 June 2009 (has links)
Over the past three decades or so, metaheuristics has been one of the most important and successful techniques for finding the true or near optimal solution of complex problems. Instead of systematically enumerating and checking all the candidate solutions that would take forever to accomplish, it works by guessing the right directions for finding the true or near optimal solution so that the space searched, and thus the time required, can be significantly reduced. However, our observation shows that most of the metaheuristic algorithms face a common problem. That is, because of the requirements of convergence, they all involve a lot of redundant computations during the convergence process. In this thesis, we present a simple but efficient algorithm for solving the problem, called the Pattern Reduction algorithm (or PR for short). The proposed algorithm is motivated by the observation that some of the sub-solutions that are repeatedly computed during the convergence process can be considered as part of the final solutions and thus can be first compressed and then removed to eliminate the redundant computations at the later iterations during the convergence process. Since PR is basically a concept that is not limited to any particular metaheuristic algorithm, we present several methods derived from the concept for eliminating the duplicate computations of metaheuristics in the thesis. Although our simulation results show that they all perform well in terms of the computation time reduced, they are not perfect in terms of the quality of the end results because in some cases they will cause a small loss of the quality. For this reason, rather than how much computation time the proposed algorithm can reduce, our ultimate goal is to eliminate all the redundant computations while at the same time preserving or even enhancing the quality of the end result of metaheuristics alone.
85

Escape dynamics in learning models /

Williams, Noah. January 2001 (has links)
Thesis (Ph. D.)--University of Chicago, Dept. of Economics, June 2001. / Includes bibliographical references. Also available on the Internet.
86

Untersuchungen zur Theorie der Folgen analytischer Funktionen

Jentzsch, Robert, January 1900 (has links)
Thesis (doctoral)--Friedrich-Wilhelms-Universität zu Berlin, 1914. / Vita. Includes bibliographical references.
87

Zur Konvergenz der trigonometrischen Reihen einschliesslich der Potenzreihen auf dem Konvergenzkreise /

Neder, Ludwig, January 1919 (has links)
Thesis (doctoral)--Georg-August-Universität zu Göttingen, 1919. / Cover title. Vita. Includes bibliographical references (p. [47]).
88

CONVERGENCE UNDER STEINER SYMMETRIZATION

Luttmann, Frederick William, 1940- January 1967 (has links)
No description available.
89

The Intertropical Convergence Zone over the Middle East and North Africa: Detection and Trends

Scott, Anna A. 05 1900 (has links)
This thesis provides an overview of identifying the Intertropical Convergence Zone (ITCZ) in the Middle East and North Africa (MENA) region. The ITCZ is a zone of wind convergence around the equator that coincides with an area of intense precipitation that is commonly termed a tropical rainbelt. In Africa, these two concepts are frequently confounded. This work studies the correlation between precipitation and commonly used ITCZ indicators. A further attempt is made to detect movement in the African ITCZ, based on earlier paleontological studies showing historical changes in precipitation. Zonally averaged wind convergence is found to be the most reliable indicator of the African ITCZ, one having a low correlation with zonally averaged precipitation. Precipitation is found only to be a reliable indicator for the African ITCZ in zones near the wind convergence, which reaches as far north as 20_N in the summer. No secular change in location of the African ITCZ is found for the time of available data. Finally, historical data shows that any increase in precipitation in the Sahel, a region where precipitation is driven by the ITCZ, is mildly negatively correlated with precipitation in the rainbelt area, suggesting that shifts in the ITCZ result in a widening of the precipitation profile as well as a shift of the entire zone.
90

Προσδιοριστικοί παράγοντες της μεγέθυνσης και σύγκλισης στην ΕΕ και στον ΟΟΣΑ / Determinants of growth and convergence in EU and OECD

Σίνος, Βασίλειος 09 October 2009 (has links)
Η οικονομική μεγέθυνση αποτελεί έναν από τους πιο δυναμικά αναπτυσσόμενους κλάδους της οικονομικής επιστήμης. Έχει κεντρίσει το ενδιαφέρον πολλών μεγάλων ερευνητών και έχει συμβάλει στην δημιουργία της νέας θεωρίας της οικονομικής μεγέθυνσης. Οι κλασικοί οικονομολόγοι προσπάθησαν να διερευνήσουν τα φαινόμενα της οικονομικής μεγέθυνσης, ωστόσο η διαδικασία αυτή ατόνησε εξαιτίας της έλλειψης κατάλληλων μαθηματικών τεχνικών και μεθόδων αλλά και εξαιτίας, της έλλειψης κατάλληλων στατιστικών στοιχείων. Η ανάπτυξη των μαθηματικών υποδειγμάτων της οικονομικής μεγέθυνσης άρχισε μετά το Δεύτερο Παγκόσμιο Πόλεμο, και συμπίπτει με την προσπάθεια ανασυγκρότησης και ανάπτυξης των κατεστραμμένων από τον πόλεμο οικονομιών. Από τα μέσα της δεκαετίας του 1980, η κατασκευή διαφόρων βάσεων δεδομένων αλλά και η εισαγωγή νέων μαθηματικών τεχνικών έδωσαν ώθηση, τόσο στην θεωρητική, όσο και στην εμπειρική έρευνα. Σκοπός της εργασίας μας είναι να μελετήσουμε την θεωρητική και την εμπειρική βιβλιογραφία της οικονομικής μεγέθυνσης και στην συνέχεια να εξετάσουμε τους προσδιοριστικούς παράγοντας της οικονομικής μεγέθυνσης και της σύγκλισης χρησιμοποιώντας δεδομένα για τις χώρες της Ευρωπαϊκής Ένωσης και για κάποιες χώρες μέλη του ΟΟΣΑ. / Economic growth constitutes one of the most dynamic developed sectors in economic science. A large number of researchers are interested to this subject and they have contributed to the development of New Growth Theory. Classical economists tried to find out the subject of economic growth, but this procedure was inefficient owing to the lack of applicable mathematical techniques, appropriate methods and data. The development of mathematical models about economic growth started just after the World War II and is related to the process of reconstruction and development of blasted economies as a result of the war. In the middle of 1980, the variety of data bases was constructed and the innovation of new mathematical methods boosted theoretical and empirical research. Our objective is to contemplate theoretical and empirical literature of economic growth and apart from that to find out the determinants of economic growth and convergence using data from countries which are members of the European Union and OECD.

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