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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.
351

Self-interference handling in OFDM based wireless communication systems [electronic resource] / by Tevfik Yücek.

Yücek, Tevfik. January 2003 (has links)
Title from PDF of title page. / Document formatted into pages; contains 93 pages. / Thesis (M.S.E.E.)--University of South Florida, 2003. / Includes bibliographical references. / Text (Electronic thesis) in PDF format. / ABSTRACT: Orthogonal Frequency Division Multiplexing (OFDM) is a multi-carrier modulation scheme that provides efficient bandwidth utilization and robustness against time dispersive channels. This thesis deals with self-interference, or the corruption of desired signal by itself, in OFDM systems. Inter-symbol Interference (ISI) and Inter-carrier Interference (ICI) are two types of self-interference in OFDM systems. Cyclic prefix is one method to prevent the ISI which is the interference of the echoes of a transmitted signal with the original transmitted signal. The length of cyclic prefix required to remove ISI depends on the channel conditions, and usually it is chosen according to the worst case channel scenario. Methods to find the required parameters to adapt the length of the cyclic prefix to the instantaneous channel conditions are investigated. / ABSTRACT: Frequency selectivity of the channel is extracted from the instantaneous channel frequency estimates and methods to estimate related parameters, e.g. coherence bandwidth and Root-mean-squared (RMS) delay spread, are given. These parameters can also be used to better utilize the available resources in wireless systems through transmitter and receiver adaptation. Another common self-interference in OFDM systems is the ICI which is the power leakage among different sub-carriers that degrades the performance of both symbol detection and channel estimation. Two new methods are proposed to reduce the effect of ICI in symbol detection and in channel estimation. The first method uses the colored nature of ICI to cancel it in order to decrease the error rate in the detection of transmitted symbols, and the second method reduces the effect of ICI in channel estimation by jointly estimating the channel and frequency offset, a major source of ICI. / System requirements: World Wide Web browser and PDF reader. / Mode of access: World Wide Web.
352

Capturing the nature of issue publics : selectivity, deliberation, and activeness in the new media environment

Chen, Hsuan-Ting, active 2013 27 September 2013 (has links)
This dissertation seeks to understand how issue publics contribute to citizen competence and the functioning of democracy. In the first part of the dissertation, a new measurement was constructed by theoretically and empirically analyzing the attributes of issue public members. Through the hypotheses testing, the new measure was more reliable in identifying issue public members compared to previous measurement strategies. Employing the new measure, results show that issue public members with concern about a specific issue, exercised their issue-specificity in seeking information (i.e., issue-based selectivity) with exposure to both attitude-consistent and counter-attitudinal perspectives. Issue public membership also had significant effects on issue-specific knowledge, and generating rationales for their own and other's oppositional viewpoints. These direct effects were mediated by issue-based selectivity. The relationships highlight the importance of issue publics in contributing to the deliberative democracy. In addition, issue publics play a significant role in contributing to the participatory democracy in that issue public members have greater intentions to participate in issue-related activities than nonmembers. However, while issue publics come close to solve the deliberative-participatory paradox, it was found that their information selectivity and argument generation were unbalanced in a way of favoring pro-attitudinal perspectives over counter-attitudinal perspectives. The second part of the dissertation examined conditional factors--accuracy and directional goals in affecting information selectivity and processing. The findings show that directional goals influenced participants to apply either the strategies of selective approach or selective avoidance to seek information depending on the issue. Accuracy goals exerted a main effect on the issue that is relatively less controversial and less obtrusive. They also interacted with issue public membership in influencing the less controversial and less obtrusive issue. Argument generation was not affected by accuracy or directional goals. Overall, through conceptualizing citizens as members of different issue publics, individuals are more competent then we thought. Their intrinsic interest in an issue serves as a strong factor affecting their information selectivity, information processing, and political actions. Despite finding an optimistic role for issue publics in the democratic process, their limitations also should be recognized. The implications for the deliberative and participatory democracy are discussed.
353

Σχεδιασμός & ανάπτυξη νέων συνθετικών αναλόγων της ωκυτοκίνης με ανταγωνιστική δράση. Σχέσεις δομής-βιολογικής δραστικότητας. / Design and synthesis of oxytocin new analogues with antagonistic activity. Relationships of conformation and biological activity.

Φραγκιαδάκη, Μαρία 24 June 2007 (has links)
Στην παρούσα διατριβή παρουσιάζεται η σύνθεση εικοσιεπτά νέων αναλόγων της ωκυτοκίνης (ΟΤ), τα οποία περιέχουν πέραν της Gly(But)8 ή/και Gly(But)9 και Gly(But)3 ή/και Gly(But)7, D-Cys6;ή Pen6, το μη φυσικό αμινοξύ α-αμινοϊσοβουτυρικό οξύ (Aib), το ιμινοξύ 1,2,3,4- τετραϋδροκινολινο-3-καρβοξυλικό οξύ (Tic) στη D- μορφή του στις θέσεις 7 ή/και 9 και τέλος τα παράγωγα D-Tyr(Et) και D-Nal(1) στη θέση 2. H σύνθεση των νέων αναλόγων έγινε σύμφωνα με την Fmoc/But μεθοδολογία σύνθεσης επί στερεάς φάσεως σε στερεό υπόστρωμα Rink Bernatowitz 2-χλωροτριτυλο-ρητίνη.Τα πεπτίδια δοκιμάστηκαν όσον αφορά στην ωκυτόκειο δράση in vitro, σε απομονωμένο ιστό μήτρας επίμυος ενώ η δοκιμή επί της πιέσεως πραγματοποιήθηκε σε επίμυες οι οποίοι είχαν επεξεργαστεί με φαινοξυβενζαμίνη. Τα νέα ανάλογα δοκιμάστηκαν και όσον αφορά στη συγγένεια τους με τον ανθρώπινο ωκυτόκειο υποδοχέα, η δοκιμή πραγματοποιήθηκε σε ανθρώπινα εμβρυϊκά νεφρικά κύτταρα (HEK) τα οποία υπερεκφράζουν τον υποδοχέα. Επιπρόσθετα, κάποια από τα ανάλογα αυτά δοκιμάστηκαν όσον αφορά στην επίδρασή τους στον πολλαπλασιασμό των καρκινικών κυττάρων του μαστού (MCF-7). Από τα προκαταρκτικά βιολογικά αποτελέσματα φαίνεται ότι τα συντεθέντα ανάλογα παρουσιάζουν στο σύνολό τους ανταγωνιστικές ιδιότητες, 10 εκ των οποίων παρουσίασαν ιδιαίτερα ισχυρή ανταγωνιστική δράση και εκλεκτικότητα εφ’ όσον στη δοκιμή επί της πιέσεως δεν εμφάνισαν δράση. Τα 10 αυτά ανάλογα εμφανίζουν ανταγωνιστική ισχυρότερη από αυτήν του Atosiban (pA2=8,29±0,05) και είναι εκλεκτικά. Επιπλέον, τρία από τα νέα ανάλογα (MOPACIN I,II και III) βρίσκονται σε διαδικασία κατοχύρωσης. Όσον αφορά την συγγένεια με τον ανθρώπινο υποδοχέα υπήρξε μια διαφοροποίηση μεταξύ των αποτελεσμάτων από τη βιολογική δράση και την συγγένεια με τον υποδοχέα, αφού ανάλογα με ισχυρή ανταγωνιστική δράση (π.χ. ανάλογο 23 με τιμή pA2 =8,31 και συγγένεια με τον υποδοχέα περισσότερο από 100 φορές χαμηλότερη σε σύγκριση με αυτή της φυσικής ορμόνης) εμφάνισαν χαμηλή συγγένεια με τον υποδοχέα. Η διαφοροποίση αυτή ίσως οφείλεται στις διαφορές μεταξύ των ειδών. Επιπρόσθετα, κάποια από τα ανάλογα αυτά δοκιμάστηκαν όσον αφορά στην επίδρασή τους στον πολλαπλασιασμό των καρκινικών κυττάρων του μαστού (MCF-7). Τα αποτελέσματα αυτών αποτελούν ένδειξη της βιολογικής δράσης των συνθετικών πεπτιδίων. Όμως χρειάζεται περισσό-τερη διερεύνηση ο ρόλος τους για την εξαγωγή ασφαλών συμπερασμάτων.Εν κατακλείδι, τα συμπεράσματα στα οποία καταλήγουμε, όσον αφορά στην παρούσα διατριβή προσφέρουν νέα δεδομένα όσον αφορά στη σύνθεση και τον σχεδιασμό νέων αναλόγων της ωκυτοκίνης τα οποία πιθανότατα θα αποτελέσουν και καλούς ανταγωνιστές με ενδεχόμενη θερα-πευτική/φαρμακευτική εφαρμογή. Επιπλέον, το εύρημα ότι η ωκυτοκίνη καθώς και τα ανάλογα αυτής μπορεί να εμπλέκονται στον πολλαπλασιασμό των νεοπλασματικών κυττάρων μπορεί να βρει εφαρμογή στην ραδιοαπεικόνιση διαφόρων νεοπλασμάτων, καθώς και στη θεραπεία αυτών. Επίσης ανάλογα της ωκυτοκίνης τα οποία παρουσιάζουν υψηλή συγγένεια με τον υποδοχέα μπορούν να χρησιμοποιηθούν ως ραδιοϊχνηθέτες ή ως χημειοθεραπευτικοί φορείς. / In the present study we present the synthesis and pharmacological investigation of twenty seven newly synthesized oxytocin analogues. Basic modification at positions 7, 8 and 9 (in-troduction of α,α-dialkyl amino acid, α-aminoisobutyric acid [Aib] or the unnatural imino acid D-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid [D-Tic] or tert-butyl-glycine [(But)Gly]) was combined with D-Cys6/Pen6, D-Tyr(Et)2, and D-Nal(1)2, Mpa1/Pen1 modifications and their various combinations.The new analogues were synthesized by Fmoc solid phase methodology utilizing a 2-chlorotrityl chloride resin as solid support bearing a Rink-Bernatowitz linker to provide the peptidic amide. The analogues were tested for their potency in two pharmacological tests, i.e. uterotonic in vitro test in the absence of magnesium ions on an isolated strip of rat uterus and in the pressοr test on phenoxybenzamine treated male rats. Parallel determination of binding affinity of the analogues to cloned human oxytocin recep-tors on HEK cell membranes using tritiated oxytocin from NEN Life Science, Boston, MA, USA was performed.We obtained a satisfactory number of quite potent and selective (as it concerns the binding with the vasopresor receptor V1a) oxytocin antagonists. Ten of these analogues showed higher antagonistic affinity than Atosiban (pA2=8.29) and they were completely inactive as far as it concerns the rat pressor test. Three of them (MOPACIN I, II and III) are under patent procedure. On the other hand, as it concerns the binding affinity and the biological evaluation, we observed a paradox phenomenon. Despite the high antagonistic potencies the affinity to the receptor was lower than oxytocin. This may be attributed to the species difference. Furthermore, some of the analogues were tested as far as it concerns their ability to in-crease or decrease the growth of MCF-7 breast cancer cells. The results indicate the ability of some analogues to decrease the growth of the MCF-7 breast cancer cells, but these re-sults need further investigation due to extract safe conclusions.Finally, the results from the presence study may aid in the design of novel and selective antagonists of oxytocin with pharmacological/pharmaceutical use. Furthermore, the evi-dence that some analogues have the ability to decrease the growth of MCF-7 cells, may find future applications in the radioimaging of different neoplasms, as wel as in their therapy, using oxytocin analogues that conserve high oxytocin receptor affinity as either radiotracers or chemiotherapeutic vectors.
354

The effect of client affiliation on the performance attributions of fund managers in South Africa

Enaw, Enih Ebot January 2011 (has links)
<p>This study seeks to evaluate the performance of unit trust managers based on their client affiliation classification. Worldwide, the number of investors investing in unit trusts is on the rise and increasingly they want to be able to evaluate the performance of the managers managing their funds so as to make better investment decisions. This increase in the asset size and number of unit trusts funds could be attributed but not limited to the low capital required for investment by small investors who before could not afford to invest in portfolios requiring large capital (Prather, Bertin, and Henker, 2004). In addition, the fund managers of these units are believed to have special skills such as market timing and stock selectivity which contribute to the performances they achieve. The evaluation of the performance of unit trust fund managers is a largely unexplored area in South Africa. As a result, the study focuses on South Africa fund managers and has as aim to evaluate the performance of two groups of fund managers (independent and dependent) who were classified based on their client affiliation structure. The client affiliation classification is as a result of the fund manager‟s clientele base. The dependent group are those who formed part of a group structure and offer other wealth management services for which their clients or investors in the unit trust services originate from within the group while the independent group are those whose clients are pulled together from diverse individuals or institutions and does not form part of a group or render other services other than fund management. Two fund types were selected namely / general equity funds and balanced funds. It has also examined the underlying skills the different groups of fund managers possess. The performance of unit trust has an effect on many parties who are related in one way or the other to the unit trust funds. The results of this study will inform individual investors, trustees and asset consultants in their decision making process of selecting a fund manager. The results of the study will be of value to the asset management industry in terms of assessing their structures and restructuring the investment service business to meet the expectations of their clients / the investors. It could also be used as a marketing tool. Publicly available historical data on the returns generated by fund managers for a five year period from&nbsp / 2005 to 2009 was obtained. Analyses were done using the independent sampled t-test and the Treynor Mazel model respectively for the different research questions posed. The results obtained indicated that there were no statistically significant differences between the performances of independent fund managers with those of dependent fund managers. However, dependent fund managers of equity funds performed better than their counterparts the independent fund managers. In the case of balanced funds, the independent fund managers performed better than their dependent counterparts. On average, both fund&nbsp / manager types possessed selectivity skills for equity funds and none for balanced funds. However for both fund types, the dependent fund manager demonstrated more selectivity skills than their independent counterparts. The results for market timing skills demonstrated that on average, both fund managers did not possess market timing skills for balanced funds while possessing these skills for equity funds. The dependent&nbsp / fund managers demonstrated more market timing skills for balanced funds though negative when compared to that of their counterparts. On the other hand, the equity fund independent fund&nbsp / managers demonstrated more market timing skills than the dependent fund managers.</p>
355

A critical appraisal of the criminalisation and prosecution of sexual violence under international criminal law

Akia, Brenda January 2011 (has links)
<p>Sexual violence leaves the victims psychologically traumatised and stigmatised in the eyes of its community. Used on a large scale, sexual violence can destabilise a society as a whole and when used during armed conflicts, it serves as a powerful weapon against members of a community. During armed conflicts, sexual violence is widespread and systematically used as a tool of war and this makes sexual violence amount to crimes against humanity, genocide and war crimes. This research paper critically analyses and evaluates sexual violence as an international crime, as well as its prosecution under international criminal law mainly by the International Criminal Court (hereafter ICC), International Criminal Tribunal for the Former Yugoslavia (hereafter ICTY) and International Criminal Tribunal for Rwanda (hereafter ICTR). It discusses the problem of selectivity that can be observed in prosecuting sexual violence that has in fact, left many victims of sexual violence dissatisfied. By doing so, it analyses the law as it is to determine whether the law applied during sexual violence prosecutions is sufficient. The paper also states recommendations that can contribute to the effective prosecution of sexual crimes under international criminal law.</p>
356

Does attentional bias to threat causally contribute to the expression of naturalistic anxiety?

Bridle, Russell January 2009 (has links)
[Truncated abstract] Over the past several decades substantial research has been conducted investigating the association between attentional bias to emotionally threatening material and anxiety. Tasks such as the emotional Stroop, the dichotic listening task and the visual probe task have been used to document this association, with the visual probe task providing the most direct means of assessing this bias. That this association exists stands beyond contention, however relatively little research has been conducted directly examining the causal nature of this relationship. By using predictive and recovery approaches it is possible to determine how attentional bias and anxiety co vary but not the exact causal nature of this relationship. However, when the visual probe methodology is used attentional bias to threat can be directly manipulated and as such it is possible to determine if attentional bias to threat causally underpins the development and maintenance of anxiety. The purpose of the current research was to deliver an extended attentional training task to anxious individuals by capitalising upon the ability to directly manipulate attentional bias using the visual probe task methodology and assessing the possible therapeutic benefits of such an approach. ...Nevertheless these results provided support for the validity of the causal hypothesis and the technological difficulties associated with administering the task online were ameliorated. Due to the fact that characteristics of both situational and dispositional anxiety are present in a clinical population a revised version of the attentional training task was administered to two groups of non-clinically anxious individuals to determine the impact that avoid threat attentional training has on each of these types of anxiety. High trait anxious students and pregnant women were chosen for this purpose but due to substantial attrition these two experiments failed to provide sufficient evidence to evaluate the causal hypothesis. Two main reasons for this attrition were identified, the motivation of participants and the procedures that were in place to monitor their progress. To ensure that attrition would not compromise future experiments a series of modifications were made and the attentional training program was then readministered to a sample of individuals characterised by dispositional or situational anxiety. A group of self labelled worriers and a sample of Immigrating Singaporean students respectively, were chosen for this purpose. There was no significant influence of avoid threat training on attentional bias for the self labelled worriers, nor any evidence of an attenuation of emotional vulnerability. For the Immigrating Singaporean students, however; there was evidence of a significant reversal of attentional bias to threat post attentional training compared to the control group and a corresponding attenuation of emotional vulnerability and a trend towards a significant attenuation of emotional reactivity. The implications for the causal hypothesis and the therapeutic applicability are discussed as well as several avenues for future research.
357

The Effects of Bottom-Tending Mobile Fishing Gear and Fiber-Optic Cable Burial on Soft-Sediment Benthic Community Structure

Nenadovic, Mateja January 2009 (has links) (PDF)
No description available.
358

Don’t look a gift horse in the mouth? Some reflections around the effects of international cooperation as an instrument to promote economic development / ¿A caballo regalado no se le mira el diente? Algunas reflexiones en torno a los efectos de la cooperación internacional como instrumento para favorecer el desarrollo económico

Venero Espinoza, Willy Hernando 10 April 2018 (has links)
The effects of foreign aid in the process of economic growth in developing countries is a subject of intense debate. While its favorable effects in the struggle with poverty are undeniable, its determining factor for economic development has positions in favor and against. This article presents a review of the literature on foreign aid, focusing on the fundamental aspects to facilitate its analysis. Other aspects that are addressed are the main arguments used to support the granting and receiving of foreign aid towards a developing country, as well as those arguments that criticize its suitability. The final part includes some conclusions about the presented arguments. / Los efectos de la cooperación internacional en el proceso de crecimiento económico de los países en desarrollo es un tema de intenso debate. Si bien sus efectos favorables en la lucha contra la pobreza resultan innegables, su condición de factor determinante para el desarrollo económico tiene posiciones a favor y en contra. En este artículo se hace una revisión de la literatura sobre la cooperación internacional, concentrándose en los factores fundamentales para facilitar su análisis. Otro aspecto tratado son los principales argumentos utilizados para respaldar el otorgamiento y recepción de cooperación internacional hacia un país en desarrollo, así como aquellos argumentos que critican su conveniencia. La parte final incluye algunas conclusiones sobre los argumentos expuestos.
359

[en] A RE-READING OF THE BRAZILIAN PENAL LAW IN THE PARADIGM OF THE DEMOCRATIC STATE / [pt] A RELEITURA DO DIREITO PENAL BRASILEIRO NO PARADIGMA DO ESTADO DEMOCRÁTICO DE DIREITO

RENATO DE VASCONCELOS FARIA 06 November 2008 (has links)
[pt] A operacionalidade real do sistema penal evidencia um amplo sistema de controle social e de pressão sobre as massas populares, em favor das elites econômicas e políticas e em prol da reprodução das relações de poder hierarquizadas, verticalizadas e disciplinadas inerentes ao modelo tardocapitalista, traduzindo o seu aspecto individualista e extremamente egoísta. O resultado dessa operacionalidade é um sistema penal seletivo e ilegítimo, que cria a criminalidade a partir de processos que recaem sobre os membros vulneráveis das classes sociais subalternas, fazendo com que eles assumam o papel de delinqüentes. A reconstrução da legitimidade do direito penal depende da reconstrução do próprio modelo de sociedade capitalista de mercado, partindo-se do ponto de vista das classes subalternas, e depende da implementação do tripé democracia participativa, efetividade plena dos direitos humanos e desenvolvimento social justo e equilibrado. A partir da reconstrução social, a reconstrução do direito penal se dará sob a orientação dos princípios constitucionais da intervenção mínima e da proporcionalidade, reservando-se o direito penal tão-somente como resposta para as violações gravíssimas dos direitos humanos. A reconstrução da legitimidade do direito penal passa também pela drástica reforma do direito penal e processual penal, das instituições policiais, judiciais e de ensino, pelo controle razoável dos meios de comunicação em massa, pela redução extrema do uso das penas detentivas, substituindo-as por modelos alternativos de efetiva solução do conflito gerado pelo crime, entre eles aqueles capazes de tornar reações individuais isoladas em consciência e ação política. / [en] The real operationality of the criminal system highlights a broad system of social control and pressure over popular classes, in favor of the politic and economic elites and in order to facilitate the reproduction of the hierarchized, verticalized and disciplined power relations which are inherent to the capitalist model, translating its individualist and extremely egoist aspect. The result of this operationality is a selective and illegitimate penal system, which creates criminality from lawsuits that fall over the vulnerable subaltern social classes, making them play the role of delinquents. The reconstruction of the legitimacy of the penal law depends on the reconstruction of the market- capitalist model itself, from the subaltern classes- point of view. It also depends on the implementation of a tripod: participative democracy, plentiful effectiveness of the human rights and fair and balanced social development. From the social reconstruction, the reconstruction of the penal law will come under the orientation of constitutional principles of minimal intervention and proportionality. This would keep the penal law responsible only for answers to very severe violations of the human rights. The reconstruction of legitimacy of the penal law goes through a drastic reform of penal law and process penal law, of the police, juridical and educational institutions, it also goes through the reasonable control of mass media, the extreme reduction of the use of detention law sentences, replacing them by alternative models for effective solution of the conflict generated by crime, including those capable of making individual isolated reactions in political consciousness and action.
360

The control of selectivity in partial oxidation of hydrocarbons

Aworinde, Samson Mayowa January 2018 (has links)
No description available.

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