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Dissertations / Theses on the topic 'Communications theory'
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1
Lo, Kam Chuen. "Encoding strategies for data communications." Thesis, University of Sunderland, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310619.
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Chng, Raymond S. K. "A parallel architecture for multimedia communications." Thesis, University of Essex, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.332803.
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Najari, Moghadam Nima. "On Multiantenna Cellular Communications: From Theory to Practice." Doctoral thesis, KTH, Teknisk informationsvetenskap, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-207623.
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Today, wireless communications are an essential part of our everyday life. Both the number of users and their demands for wireless data have increasedtremendously during the last decade. Multiantenna communicationsis a promising solution to meet this ever-growing traffic demands. However, impairments that exist in most practical communication networks may substantially limit the performance of a multiantenna system. The characterizationof such a performance loss and how to minimize that are still largelyopen problems. The present thesis addresses this important research gap. Inparticular, we focus on three major impairments of a multiantenna cellularnetwork: impairment in the channel state information (CSI), interference andimpairment in the transceiver hardware components.To fully realize the benefits of multiantenna communications, the users need to acquire a certain level of information about their propagation environment; that is, their corresponding CSI. In practice, the CSI is not known bythe users and should be acquired by allocating part of the network resourcesfor pilot transmission. This problem is mainly important in the systems with a large number of antennas, as in general the required network resources for CSI acquisition scales with the number of transmitting antennas. Theproblem of CSI acquisition in a single-cell multiuser multiple-input multipleoutput(MIMO) system is addressed in this thesis. A linear spatial precodingand combining scheme for pilot transmission is proposed. This scheme requiresless number of network resources for channel estimation compared tothe conventional schemes. The gains of the proposed scheme are characterized by finding an upper-bound and a lower-bound on the channel estimation error.Moreover, as an ultimate performance metric, an achievable sum-rate ofthe network is formulated and analyzed numerically.Due to the broadcast nature of the wireless channels, the performanceof the users in a network is intertwined; the desired signal of one user mayinterfere other users. Hence, the interference is another major impairment inwireless communication systems. In this thesis, the practical challenges of aninterference management technique, namely MIMO interference alignment isinvestigated by implementation on a multiuser MIMO testbed. Then, in thecontext of interference alignment, the problem of optimal power allocation forpilot and data transmission is studied and verified by the measurements.The impairment in the hardware components of the transceivers, that is, any deviation of the components from their ideal behavior, degrades the performance of a communication system. In particular, the impact of nonlineartransmitter power amplifiers (PA)s is investigated in this thesis. First, consideringa memoryless third-order polynomial model for the PAs, a model forthe transmitted nonlinear distortion signal from a multiantenna transmitter isproposed and validated by measurements. This model implies that the spatialdirection of the transmitted distortion is dependent on the spatial directionof the desired signal. Then, this model is extended for a general arbitrary order polynomial model. Exploiting the developed distortion model, the energyefficiency of a multiantenna system operating at millimeter wave frequenciesis studied.<br><p>QC 20170523</p>
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Zhao, Jingjing. "Resource allocation for D2D communications based on matching theory." Thesis, Queen Mary, University of London, 2017. http://qmro.qmul.ac.uk/xmlui/handle/123456789/25990.
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Device-to-device (D2D) communications underlaying a cellular infrastructure takes advantage of the physical proximity of communicating devices and increasing resource utilisation. However, adopting D2D communications in complex scenarios poses substantial challenges for the resource allocation design. Meanwhile, matching theory has emerged as a promising framework for wireless resource allocation which can overcome some limitations of game theory and optimisation. This thesis focuses on the resource allocation optimisation for D2D communications based on matching theory. First, resource allocation policy is designed for D2D communications underlaying cellular networks. A novel spectrum allocation algorithm based on many-to-many matching is proposed to improve system sum rate. Additionally, considering the quality-of-service (QoS) requirements and priorities of di erent applications, a context-aware resource allocation algorithm based on many-to-one matching is proposed, which is capable of providing remarkable performance enhancement in terms of improved data rate, decreased packet error rate (PER) and reduced delay. Second, to improve resource utilisation, joint subchannel and power allocation problem for D2D communications with non-orthogonal multiple access (NOMA) is studied. For the subchannel allocation, a novel algorithm based on the many-to-one matching is proposed for obtaining a suboptimal solution. Since the power allocation problem is non-convex, sequential convex programming is adopted to transform the original power allocation problem to a convex one. The proposed algorithm is shown to enhance the network sum rate and number of accessed users. Third, driven by the trend of heterogeneity of cells, the resource allocation problem for NOMA-enhanced D2D communications in heterogeneous networks (HetNets) is investigated. In such a scenario, the proposed resource allocation algorithm is able to closely approach the optimal solution within a limited number of iterations and achieves higher sum rate compared to traditional HetNets schemes. Thorough theoretical analysis is conducted in the development of all proposed algorithms, and performance of proposed algorithm is evaluated via comprehensive simulations. This thesis concludes that matching theory based resource allocation for D2D communications achieves near-optimal performance with acceptable complexity. In addition, the application of D2D communications in NOMA and HetNets can improve system performance in terms of sum rate and users connectivity.
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Chaudhry, Mohammed Sabih. "Microwave I.F signal processing strategies for coherent optical communications." Thesis, Bangor University, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.357247.
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Cao, Lei. "Error resilient image coding and wireless communications /." free to MU campus, to others for purchase, 2002. http://wwwlib.umi.com/cr/mo/fullcit?p3052160.
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Nitz, Michael Earl 1967. "Schema theory: An application to political communication." Thesis, The University of Arizona, 1991. http://hdl.handle.net/10150/291606.
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Political schema research (Kinder, Peters, Abelson, & Fiske, 1980; Miller, Wattenberg, & Malanchuk, 1986) has centered on the schemas voters use to select presidents. Unfortunately, political researchers have all but neglected the state and local level. Consequently, this thesis focuses on the schemas voters use to select governors to determine if these schemas differ from schemas used to select presidents. This thesis also tests the relationship between political sophistication and the use of certain schemas to select a governor. Surveys were administered to 563 adults waiting for jury duty. Results indicate the schemas voters use to select governors differ from those used to select presidents. Political sophistication is positively related to usage of issues and performance schemas. Further research should explore political schemas at state and local levels.
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Abegaze, A. "Assessment of speech synthesis systems for application in mobile communications." Thesis, University of Bradford, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.380392.
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Wallace, Brian John Michael. "Some applications of discrete mathematics to the theory of communications." Thesis, Royal Holloway, University of London, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.272153.
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Durgin, Gregory David. "Theory of Stochastic Local Area Channel Modeling for Wireless Communications." Diss., Virginia Tech, 2000. http://hdl.handle.net/10919/29843.
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This dissertation outlines work accomplished in the pursuit of this degree. This report is also designed to be a general introduction to the concepts and techniques of small-scale radio channel modeling. At the present time, there does not exist a comprehensive introduction and overview of basic concepts in this field. Furthermore, as the wireless industry continues to mature and develop technology, the need is now greater than ever for more sophisticated channel modeling research.
Each chapter of this preliminary report is, in itself, a stand-alone topic in channel modeling theory. Culled from original reports and journal papers, each chapter makes a unique contribution to the field of channel modeling. Original contributions in this report include:
1. joint characterization of time-varying, space-varying, and frequency-varying channels under the rubric of duality
2. rules and definitions for constructing channel models that solve Maxwell's equations
3. overview of probability density functions that describe random small-scale fading
4. techniques for modeling a small-scale radio channel using an angle spectrum
5. overview of techniques for describing fading statistics in wireless channels
6. results from a wideband spatio-temporal measurement campaign
Together, the chapters provide a cohesive overview of basic principles. The discussion of the wideband spatio-temporal measurement campaign at 1920 MHz makes an excellent case study in applied channel modeling and ties together much of the theory developed in this dissertation.<br>Ph. D.
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Kemp, Andrew Harold. "Complementary sequences and their application in multi-functional communications system architectures." Thesis, University of Hull, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.384863.
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Collins, M. J. "Improvements in track to train communications for railway jointless track circuits." Thesis, University of Bath, 1997. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.362264.
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Forrett, Steven Lawrie. "Movie poster advertisements: A relevance theory persepctive." CSUSB ScholarWorks, 2007. https://scholarworks.lib.csusb.edu/etd-project/3236.
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The purpose of this thesis is to examine ten movie posters while hypothesizing whether or not their tagline texts could interest a reader. A linguistic framework Relevance Theory, is used in the analysis of this project.
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Dempsey, Jennifer Camille. "Virtualizing the word| Expanding Walter Ong's theory of orality and literacy through a culture of virtuality." Thesis, Duquesne University, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=3615934.
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<p> This dissertation seeks to create a vision for virtuality culture through a theoretical expansion of Walter Ong's literacy and orality culture model. It investigates the ubiquitous and multimodal nature of the virtuality cultural phenomenon that is mediated by contemporary technology and not explained by pre-existing cultural conventions. Through examining the theoretical underpinnings of orality and literacy culture, the dissertation explores the cultural shift that is just beginning to restructure human consciousness through the ways that society is connecting, exploring and communicating. Further, this dissertation examines the contrasts between virtuality culture features and those related to traditional literacy and orality types, including the gap between the theory of secondary orality and virtuality culture. This dissertation also proposes three ways that contemporary technology creates human presence related to virtuality culture. Finally, this dissertation describes the broad implications for the evolution of virtuality culture in areas such as education, technology, literacy, philosophy, politics, linguistics, ethics, history, the arts and cultural studies.</p>
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Kalason, Patrick. "Théorie constructale des communications trifonctionnelles." Thesis, Toulouse 2, 2011. http://www.theses.fr/2011TOU20152.
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Les propos de cette thèse princeps s’inscrivent dans une démarche qui consiste à rétablir dans sa fonction seconde, en sciences humaines et sociales, l’approche dite cartésienne comme étant la conséquence cartographique d’une approche préliminaire trifonctionnelle (trikãlienne) telle que l’a mise au jour le philologue Georges Dumézil. Le tout permettant de faire entrer les sciences de l’information et des communications dans une dimension constructale quelques soient les problématiques soulevées. La théorie constructale des communications est phénoménologique et fait lien avec la loi constructale mise au jour par Adrian Bejan.La loi de Constructal, telle qu’elle a été mise au jour par Adrian Bejan, professeur et inventeur de la théorie constructale des formes et de leurs évolutions dans la nature, est celle qui régit le phénomène universel de l’évolution de la production et de l'évolution des configurations (formes, structures, rythmes) des systèmes animés, inanimés autant qu’humains. Au niveau global, la loi de Constructale des communications, sur modèle trifonctionnel de Patrick Kalason, explique la topographie que prennent les formes communicationnelles (richesse et complexité).Dans cette thèse, Patrick Kalason, découvreur de la théorie constructale des communications sur fondements systémiques trifonctionnels, propose des nouvelles clefs d’accès à la compréhension des formes issues de la sociodynamique telles que les pratiques religieuses, les processus de négociation, la pédagogie et les mécanismes sémiologiques qui sous-tendent les changements sociétaux<br>The comments of this princeps thesis in communication join a step which consists in restoring in human and social sciences the called “cartesian approach” in his second function as being the cartographic consequence of a preliminary approach trifunctional (trikãlian model) such as brought the one to light by the philologist Georges Dumezil . Allowing the whole to integrate into constructal dimension of the information and the communication sciences whatever the issues raised.The Constructal Law, such as brought to light by Adrian Bejan, professor and proponent of the constructal theory of design and evolution in nature, governs the universal phenomenon of generation and evolution of design (shape, structure, rhythm) in animate, inanimate and human systems. At the global level, the Constructal Law of communication, with a triadic model, accounts for the topography and design of human communication (wealth & complexity). In this thesis, Patrick Kalason, proponent of a constructal and trifunctional systematic approach in communications, proposes new keys to understand the emergency of sociodynamic forms such as religious practices, negotiation processes, pedagogy, and communication (semiology) mechanisms underlying social changes
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Holton, Carolyn F. "The impact of computer mediated communication systems monitoring on organizational communications content." [Tampa, Fla] : University of South Florida, 2008. http://purl.fcla.edu/usf/dc/et/SFE0002440.
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Shaheem, Asri. "Iterative detection for wireless communications." University of Western Australia. School of Electrical, Electronic and Computer Engineering, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0223.
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[Truncated abstract] The transmission of digital information over a wireless communication channel gives rise to a number of issues which can detract from the system performance. Propagation effects such as multipath fading and intersymbol interference (ISI) can result in significant performance degradation. Recent developments in the field of iterative detection have led to a number of powerful strategies that can be effective in mitigating the detrimental effects of wireless channels. In this thesis, iterative detection is considered for use in two distinct areas of wireless communications. The first considers the iterative decoding of concatenated block codes over slow flat fading wireless channels, while the second considers the problem of detection for a coded communications system transmitting over highly-dispersive frequency-selective wireless channels. The iterative decoding of concatenated codes over slow flat fading channels with coherent signalling requires knowledge of the fading amplitudes, known as the channel state information (CSI). The CSI is combined with statistical knowledge of the channel to form channel reliability metrics for use in the iterative decoding algorithm. When the CSI is unknown to the receiver, the existing literature suggests the use of simple approximations to the channel reliability metric. However, these works generally consider low rate concatenated codes with strong error correcting capabilities. In some situations, the error correcting capability of the channel code must be traded for other requirements, such as higher spectral efficiency, lower end-to-end latency and lower hardware cost. ... In particular, when the error correcting capabilities of the concatenated code is weak, the conventional metrics are observed to fail, whereas the proposed metrics are shown to perform well regardless of the error correcting capabilities of the code. The effects of ISI caused by a frequency-selective wireless channel environment can also be mitigated using iterative detection. When the channel can be viewed as a finite impulse response (FIR) filter, the state-of-the-art iterative receiver is the maximum a posteriori probability (MAP) based turbo equaliser. However, the complexity of this receiver's MAP equaliser increases exponentially with the length of the FIR channel. Consequently, this scheme is restricted for use in systems where the channel length is relatively short. In this thesis, the use of a channel shortening prefilter in conjunction with the MAP-based turbo equaliser is considered in order to allow its use with arbitrarily long channels. The prefilter shortens the effective channel, thereby reducing the number of equaliser states. A consequence of channel shortening is that residual ISI appears at the input to the turbo equaliser and the noise becomes coloured. In order to account for the ensuing performance loss, two simple enhancements to the scheme are proposed. The first is a feedback path which is used to cancel residual ISI, based on decisions from past iterations. The second is the use of a carefully selected value for the variance of the noise assumed by the MAP-based turbo equaliser. Simulations are performed over a number of highly dispersive channels and it is shown that the proposed enhancements result in considerable performance improvements. Moreover, these performance benefits are achieved with very little additional complexity with respect to the unmodified channel shortened turbo equaliser.
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Tan, Jun. "Iterative decoding and multicarrier modulation for wireless communications." Diss., Georgia Institute of Technology, 2003. http://hdl.handle.net/1853/13274.
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Lewis, Peter M. "Community media : field, theory, policy." Thesis, London Metropolitan University, 2010. http://repository.londonmet.ac.uk/1217/.
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The submission consists of twenty-three outputs, spanning over three decades. These range from books and chapters to reports, journal articles and edited publications. The accompanying commentary aims to set the submitted work in context, demonstrate that it constitutes a coherent whole, and that it makes an independent and original contribution to knowledge and the advancement of the academic field of community media within the discipline of media studies. A number of overlapping contexts are summarised: the socio-historical setting in which the practice of electronic community media first emerged; the ‘personal/professional’ context in which reflection on practical experience led to developments in theory and policy analysis; the academic context of the development of British media studies where at first radio was marginalised and there was no discursive space for the notion of community media, then a later stage where a wider range of theoretical contexts brought community and alternative media into the academic frame. Three main sections discuss, respectively, the candidate’s contribution to the identification and categorisation of community media, the application to it of theoretical perspectives, and the development of policy analysis. All three areas, it is argued, were part of a wider strategy aimed at bringing recognition to the field and which involved activities outside the scope of the submission (advocacy, interventions in mainstream media) but which are part of the context of the submitted work. For that reason an appendix (B) lists all the candidate’s publications on the subject, while others list conference presentations and other relevant activities. In addition, the documentation includes a brief career summary and statements by co-authors.
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Fan, Pingzhi. "Code design and analysis for multiple access communications." Thesis, University of Hull, 1994. http://hydra.hull.ac.uk/resources/hull:5864.
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This thesis explores various coding aspects of multiple access communications, mainly for spread spectrum multiaccess(SSMA) communications and collaborative coding multiaccess(CCMA) communications. Both the SSMA and CCMA techniques permit efficient simultaneous transmission by several users sharing a common channel, without subdivision in time or frequency. The general principle behind these two multiaccess schemes is that one can find sets of signals (codes) which can be combined together to form a composite signal; on reception, the individual signals in the set can each be recovered from the composite signal. For the CCMA scheme, the isolation between users is based on the code structure; for the SSMA scheme, on the other hand, the isolation between users is based on the autocorrelation functions(ACFs) and crosscorrelation functions (CCFs) of the code sequences. It is clear that, in either case, the code design is the key to the system design. For the CCMA system with a multiaccess binary adder channel, a class of superimposed codes is analyzed. It is proved that every constant weight code of weight w and maximal correlation λ corresponds to a subclass of disjunctive codes of order T < w/λ. Results related to the decomposition of the disjunctive codes in the noiseless and noisy cases are derived. Decoding algorithms for both the noiseless and the noisy cases are proposed. For the CCMA system operating over a multiaccess Q-ary adder channel, a class of cyclic uniquely decodable codes is proposed and analyzed by employing cyclic codes with symbols from an arbitrary finite integer rings. A very low complexity decoding procedure is presented. For a synchronous SSMA system, a new approach employing orthogonal complementary sets is presented; the properties of such orthogonal complementary sets are studied in detail. Recursive formulas for constructing orthogonal complementary sets are given. Methods for synthesizing new orthogonal complementary sets from known ones with the same dimensions are also discussed. For an asynchronous SSMA system, several new spreading codes are presented and studied: 1. A new class of polyphase codes with two-valued periodic ACF and CCF properties is derived. It is proved that, for a given prime length L > 3, the out-of-phase ACFs and CCFs of the codes are constant and equal to √L. In addition, all codes of the same length are mutually orthogonal. 2. Maximal length sequences (m-sequences) over Gaussian integers, suitable for use with QAM modulation, are considered. Two sub-classes of m-sequences with quasi-perfect periodic autocorrelations are obtained. The CCFs between the decimated m-sequences are studied. By applying a simple operation, it is shown that some m-sequences over rational and Gaussian integers can be transformed into perfect sequences with impulsive ACFs. 3. Frank codes and Chu codes have perfect periodic ACFs and optimum periodic CCFs. In addition, it is shown that they also have very favourable nonperiodic ACFs; some new results concerning the behaviour of the nonperiodic ACFs are derived. Further, it is proved that the sets of combined Frank/Chu codes, which contain a larger number of codes than either of the two constituent sets, also have very good periodic CCFs. Based on Frank codes and Chu codes, two interesting classes of real-valued codes with good correlation properties are defined. It is shown that these codes have periodic complementary properties and good periodic and nonperiodic ACF/CCFs. Finally, a hybrid CCMA/SSMA coding scheme is proposed. This new hybrid coding scheme provides a very flexible and powerful multiple accessing capability and allows simple and efficient decoding. Given an SSMA system with K users and a CCMA system with N users, where at most T users are active at any time, then the hybrid system will have K . N users with at most T.K users active at any time. The hybrid CCMA/SSMA coding scheme is superior to the individual CCMA system or SSMA system in terms of information rate, number of users, decoding complexity and external interference rejection capability.
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Johansson, Mathias. "Resource Allocation under Uncertainty : Applications in Mobile Communications." Doctoral thesis, Uppsala University, Signals and Systems Group, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-4559.
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<p>This thesis is concerned with scheduling the use of resources, or allocating resources, so as to meet future demands for the entities produced by the resources. We consider applications in mobile communications such as scheduling users' transmissions so that the amount of transmitted information is maximized, and scenarios in the manufacturing industry where the task is to distribute work among production units so as to minimize the number of missed orders.</p><p>The allocation decisions are complicated by a lack of information concerning the future demand and possibly also about the capacities of the available resources. We therefore resort to using probability theory and the maximum entropy principle as a means for making rational decisions under uncertainty.</p><p>By using probabilities interpreted as a reasonable degree of belief, we find optimum decision rules for the manufacturing problem, bidding under uncertainty in a certain type of auctions, scheduling users in communications with uncertain channel qualities and uncertain arrival rates, quantization of channel information, partitioning bandwidth between interfering and non-interfering areas in cellular networks, hand-overs and admission control. Moreover, a new method for making optimum approximate Bayesian inference is introduced.</p><p>We further discuss reasonable optimization criteria for the mentioned applications, and provide an introduction to the topic of probability theory as an extension to two-valued logic. It is argued that this view unifies a wide range of resource-allocation problems, and we discuss various directions for further research.</p>
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Briglauer, Wolfgang, and Christian Holzleitner. "Efficient contracts for government intervention in promoting next generation communications networks." Forschungsinstitut für Regulierungsökonomie, WU Vienna University of Economics and Business, 2012. http://epub.wu.ac.at/3641/1/briglauer_holzleitner_efficient_contracts.pdf.
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Although the future socio-economic benefits of a new fibre-based ("next generation access", NGA) telecommunications infrastructure seem to be uncontroversial, most countries have to date only undertaken NGA investments on a small scale. Accordingly, a universal NGA coverage appears to be a rather unrealistic objective without government intervention. Indeed, many governments have already initiated diverse subsidy programs in order to stimulate NGA infrastructure deployment. We contend, however, that the current contract practice of fixing ex ante targets for network expansion is inefficient given the uncertainty about future returns on NGA infrastructure-based services and the public authorities' incomplete information about the capital costs of the network provider. This paper puts forward to delegate the choice of the network expansion to the NGA provider. Simple linear profit-sharing contracts can be designed to control the NGA provider's incentives and to put in balance the public objectives of network expansion and limitation of public expenditure. (author's abstract)<br>Series: Working Papers / Research Institute for Regulatory Economics
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So, Daniel Ka Chun. "MIMO wireless communications in frequency selective fading channels /." View Abstract or Full-Text, 2003. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202003%20SO.
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Thesis (Ph. D.)--Hong Kong University of Science and Technology, 2003.<br>Includes bibliographical references (leaves 136-144). Also available in electronic version. Access restricted to campus users.
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Williams, Beulah Lavell. "Impact of Work-Related Electronic Communications Behavior Outside of Normal Working Hours." ScholarWorks, 2019. https://scholarworks.waldenu.edu/dissertations/6958.
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Employers' reliance on asynchronous electronic communications, connective technology devices, and remote work arrangements has led employees to feel preoccupied with staying connected after-hours to be responsive to work-related demands. The purpose of this transcendental phenomenological study was to describe the lived experiences of professional workers who coped with constant pressure to monitor and immediately respond to work-related electronic communications during nonwork hours. The conceptual framework was supported by boundary and border theory and the constructs of work-life balance, flexible work arrangements, information and communication technology. Data were collected using semistructured interviews with 16 professional workers near Washington, DC. Moustakas's modified van Kaam method was used to analyze, code, and organize data. Six themes emerged: mobilize or immobilize, manage expectations, safeguard personal time, work-life fusion, work engagement, and psychological outcomes. Findings revealed that professional workers felt a sense of urgency to reply to work-related e-mails and text messages outside of their regularly scheduled work hours and felt a sense of professional obligation to be available after-hours. Results may be used to shape and support positive social change through effective organizational change programs for technology-related work-life imbalances, thereby benefiting employers and employees.
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Averett, Paige. "Parental Communications and Young Women's Struggle for Sexual Agency." Diss., Virginia Tech, 2004. http://hdl.handle.net/10919/30091.
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This qualitative study examined how 14 young women's sexual desire and agency was influenced by the messages communicated from their parents and the quality of the parent-child relationship. Previous research results were supported, such as: parents do not communicate about sex frequently, or only about limited topics; mothers communicate more frequently than fathers, and peers communicate more sexual information. Utilizing a postmodern, feminist position, themes of parental transmission of patriarchal social controls were found, such as: fear of being viewed as a slut, gender roles that demand female passivity, sex is scary, and young women are not to have sex, or only in the context of committed relationships. Implications for parenting practices and the importance of developing sexual agency are discussed.<br>Ph. D.
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Ghanem, Samah A. M. "Analysis, modeling, design and optimization of future communications systems: from theory to practice." Doctoral thesis, Universidade de Aveiro, 2013. http://hdl.handle.net/10773/12098.
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Doutoramento em Telecomunicações e Engenharia Eletrónica (MAP-Tele)<br>Esta tese descreve uma framework de trabalho assente no paradigma multi-camada
para analisar, modelar, projectar e optimizar sistemas de comunicação. Nela se explora uma nova perspectiva acerca da camada física que nasce das relações entre a teoria de informação, estimação, métodos probabilísticos, teoria da comunicação e codificação.
Esta framework conduz a métodos de projecto para a próxima geração de sistemas
de comunicação de alto débito. Além disso, a tese explora várias técnicas de camada de acesso com base na relação entre atraso e débito para o projeto de redes sem fio tolerantes a atrasos. Alguns resultados fundamentais sobre a interação entre a teoria da informação e teoria da estimação conduzem a propostas de um paradigma alternativo para a análise, projecto e optimização de sistemas de comunicação. Com base em estudos sobre a relação entre a informação recíproca e MMSE, a abordagem descrita na tese permite ultrapassar, de forma inovadora, as dificuldades inerentes à optimização das taxas de transmissão de informação confiáveis em sistemas de comunicação, e permite a exploração da atribuição óptima de potência e estruturas óptimas de pre-codificação para diferentes modelos de canal: com fios, sem fios e ópticos. A tese aborda também o problema do atraso, numa tentativa de responder a questões levantadas pela enorme procura de débitos elevados em sistemas de comunicação. Isso é feito através da proposta de novos modelos para sistemas com codificação de rede
(network coding) em camadas acima da sua camada física. Em particular, aborda-se a utilização de sistemas de codificação em rede para canais que variam no tempo e são sensíveis a atrasos. Isso foi demonstrado através da proposta de um novo modelo e esquema adaptativo, cujos algoritmos foram aplicados a sistemas sem fios com desvanecimento (fading) complexo, de que são exemplos os sistemas de comunicação via satélite. A tese aborda ainda o uso de sistemas de codificação de rede em cenários de transferência (handover) exigentes. Isso é feito através da proposta de novos modelos de transmissão WiFi IEEE 801.11 MAC, que são comparados com codificação de rede, e que se demonstram possibilitar transferência sem descontinuidades. Pode assim dizer-se que esta tese, através de trabalho de análise e de propostas suportadas por simulações, defende que na concepção de sistemas de comunicação se devem considerar estratégias de transmissão e codificação que sejam não só próximas da capacidade dos canais, mas também tolerantes a atrasos, e que tais estratégias têm de ser concebidas tendo em vista características do canal e a camada física.<br>This thesis provides a novel framework based on multi-layer paradigms, to analyze,
model, design, and optimize future communications systems. The thesis exploits a
novel physical layer framework based on the interplay between information theory,
estimation theory, probability methods, communication theory and coding techniques.
This framework leads to proposals of design methods for next generation-very high
data rate communication systems. In addition, this thesis exploits multiple access
layer techniques based on the interplay between delay and throughput performance
for the design of wireless delay tolerant networks. Building upon foundational work on
the interplay between information theory and estimation theory, leading to proposals
of an alternative paradigm for the analysis, design and optimization of communication
systems. Based on new studies of the relation between the mutual information and
the MMSE, this approach overcomes, in an innovative way, the inherent difficulties
concerning the optimization of the reliable information transmission rates of key
communication systems and allows the exploitation of the optimal power allocation
and optimal precoding structures for different wireless and wired/optical channel
models. The thesis also addresses the delay problem, to accommodate the huge
demand of high data rates in communication systems. This is done through the
proposal of new models and designs for systems that adopt network coding mechanisms
in layers above its physical layer. In particular, this research work addresses the
usage of network coding schemes for time varying channels that are delay sensitive.
This was demonstrated via the proposal of a new model that has led to a novel
adaptive scheme, which in turn is implemented in algorithms and applied to wireless
systems with complex fading behavior, such as satellite systems. Furthermore, the
thesis addresses the usage of network coding schemes in mobile and delay stringent
handover scenarios. This is done through the proposal of novel models of the WiFi
IEEE 802.11 MAC layer transmission techniques which are evaluated in comparison
with network coding scheme, and demonstrated by solutions to novel formulations
that allow seamless handover of the mobile station. Therefore, this thesis, through
analytical work and design proposals backed by modeling and simulation studies
establishes the fact that future telecommunication system designs should consider
transmission and coding strategies that are not only capacity achieving, but also delay
tolerant and that such design have to be done with care and awareness of the physical
layer and the communication channel behavior.
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Zhang, Xiuyin. "Novel RF resonators and bandpass filters for wireless communications : theory, design and application /." access full-text access abstract and table of contents, 2009. http://libweb.cityu.edu.hk/cgi-bin/ezdb/thesis.pl?phd-ee-b23750832f.pdf.
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Thesis (Ph.D.)--City University of Hong Kong, 2009.<br>"Submitted to the Department of Electronic Engineering in partial fulfillment of the requirements for the degree of Doctor of Philosophy." Includes bibliographical references (leaves 141-158)
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Chandran, Naveen. "Hybrid ARQ with parallel and serial concatenated convolutional codes for next generation wireless communications." Morgantown, W. Va. : [West Virginia University Libraries], 2001. http://etd.wvu.edu/templates/showETD.cfm?recnum=2038.
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Thesis (M.S.)--West Virginia University, 2001.<br>Title from document title page. Document formatted into pages; contains xi, 113 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 110-112).
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Huang, Yuheng. "Bit-interleaved coded modulation with iterative decoding for wireless communications /." Thesis, Connect to this title online; UW restricted, 2004. http://hdl.handle.net/1773/5903.
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Greene, Hayley Rose. "The practice of mobile phone advertising in Japan: A grounded theory approach to looking at consumer perceptions." Thesis, University of Ottawa (Canada), 2009. http://hdl.handle.net/10393/28354.
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This research examines consumer perceptions towards the practice of mobile phone advertising in Japan. The research follows a grounded theory approach, guided by Strauss and Corbin (1998). The primary research was conducted in Tokyo. It was found that in Japan's technologically advanced society, advertisers desired to reach consumers on their 3B mobile phones. However, use of these devices differed among demographic segmentations and consumers held unfavourable views towards the overload of irrelevant incoming ads. As a result, the recommendations made for the Japanese mobile advertising industry were: (1) for advertisers to use Bayesian Networks to create highly targeted ads; (2) to improve communication between advertisers and mobile phone engineers, and (3) to discontinue lacklustre text only ads and create innovative multimedia ads. This research contributes to the literature on new media advertising by providing insight into an important component of the mobile phone advertising phenomenon: audience research.
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Nguyen, Chien Ngoc. "Simulation of spread spectrum communication systems." Thesis, Georgia Institute of Technology, 1991. http://hdl.handle.net/1853/16438.
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Welch, Daniel. "Understanding the commercial field of sustainability communications." Thesis, University of Manchester, 2013. https://www.research.manchester.ac.uk/portal/en/theses/understanding-the-commercial-field-of-sustainability-communications(e2335722-dfe4-47c0-997c-fe189544a273).html.
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The commercial field of sustainability communications encompasses ground previously demarcated between the fields of Corporate Social Responsibility on the one hand, and marketing, advertising and public relations on the other. This thesis examines the formation and development of this novel field of cultural production and its significance for sustainable consumption and corporate sustainability. The research is orientated by practice theory and draws on participant observation within a sustainability communications agency, interviews and documentary analysis. The heuristic value of practice theory for the study of sustainable consumption is now well established in the context of end-use consumption but is unexplored in the context of commercial sustainability communications. Equally, sustainability communications has been neglected by the field of cultural economy. The key concern is with cultural intermediaries and their capacity or otherwise to instantiate their own mores, understandings and practices in the social world. I address this in terms of sustainability and draw on the idea of performativity to approach commercial sustainability communications as a performative complex of practices. Furthermore, the research aims to problematise the place of 'the consumer' in discourses of sustainable consumption. I produce a genealogy of sustainability communications and an account of the development and contemporary constitution of the associated agency market. I suggest that a defining role that the market plays is the management of the 'strategic ambiguity' of sustainability. Drawing on fieldwork and interviews I identify elements that integrate practices into the complex of sustainability communications and examine its normative orientations. Cultural intermediation is shown to take place through, firstly, the diffusion of practices and practice elements. Secondly, it occurs through attempts to instantiate 'the sustainable consumer'. Models of the consumer at work in sustainability communications are analysed and different modes of instantiation of 'the sustainable consumer' identified. Thirdly, it takes place through articulating sustainability with brands. I explore three arenas in which sustainability communications articulates brand and sustainability: what I identify as the discourse of corporate-sponsored sustainable consumption; the cultural politics of work; and lastly, the public sphere.
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Li, Xiaodong. "Bandwidth-efficient coded modulation and iterative decoding /." Thesis, Connect to this title online; UW restricted, 1998. http://hdl.handle.net/1773/6017.
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Glade, William Daniel. "Way-Finding: A New Approach to Studying Digital Communications." BYU ScholarsArchive, 2019. https://scholarsarchive.byu.edu/etd/8554.
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This work further develops the way-finding model first proposed by Pearson and Kosicki (2017) which examines the flow of information in the digital age. Way-finding systems are online systems that help individuals find information—i.e. social media, search engines, email, etc. Using a grounded theory methodology, this new framework was explored in greater detail. Way-finding theory was created using the context of the elaboration likelihood model, gatekeeping theory, algorithmic gatekeepers, and the existence of the filter bubble phenomenon. This study establishes the three basic pillars of way-finding theory: the user’s mindset when accessing way-finding systems, the perception of how popular way-finding systems function, and the perception of the information personalization process—particularly regarding algorithmic gatekeepers and their roles in creating the filter bubble phenomenon. These pillars and the relationships that exist between each constitute way-finding theory.
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Haugtvedt, Candace Louise. "Enhancing adherence to antibiotic regimens : a test of protection motivation theory and persuasive communications /." The Ohio State University, 1998. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487950153601017.
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Xu, T. "Bandwidth compressed waveform and system design for wireless and optical communications : theory and practice." Thesis, University College London (University of London), 2017. http://discovery.ucl.ac.uk/1570350/.
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This thesis addresses theoretical and practical challenges of spectrally efficient frequency division multiplexing (SEFDM) systems in both wireless and optical domains. SEFDM improves spectral efficiency relative to the well-known orthogonal frequency division multiplexing (OFDM) by non-orthogonally multiplexing overlapped sub-carriers. However, the deliberate violation of orthogonality results in inter carrier interference (ICI) and associated detection complexity, thus posing many challenges to practical implementations. This thesis will present solutions for these issues. The thesis commences with the fundamentals by presenting the existing challenges of SEFDM, which are subsequently solved by proposed transceivers. An iterative detection (ID) detector iteratively removes self-created ICI. Following that, a hybrid ID together with fixed sphere decoding (FSD) shows an optimised performance/complexity trade-off. A complexity reduced Block-SEFDM can subdivide the signal detection into several blocks. Finally, a coded Turbo-SEFDM is proved to be an efficient technique that is compatible with the existing mobile standards. The thesis also reports the design and development of wireless and optical practical systems. In the optical domain, given the same spectral efficiency, a low-order modulation scheme is proved to have a better bit error rate (BER) performance when replacing a higher order one. In the wireless domain, an experimental testbed utilizing the LTE-Advanced carrier aggregation (CA) with SEFDM is operated in a realistic radio frequency (RF) environment. Experimental results show that 40% higher data rate can be achieved without extra spectrum occupation. Additionally, a new waveform, termed Nyquist-SEFDM, which compresses bandwidth and suppresses out-of-band power leakage is investigated. A 4th generation (4G) and 5th generation (5G) coexistence experiment is followed to verify its feasibility. Furthermore, a 60 GHz SEFDM testbed is designed and built in a point-to-point indoor fiber wireless experiment showing 67% data rate improvement compared to OFDM. Finally, to meet the requirements of future networks, two simplified SEFDM transceivers are designed together with application scenarios and experimental verifications.
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Tran, Le Chung. "Complex orthogonal space-time processing in wireless communications." Access electronically, 2006. http://www.library.uow.edu.au/adt-NWU/public/adt-NWU20060726.133841/index.html.
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Hoydis, Jakob. "Random matrix theory for advanced communication systems." Phd thesis, Supélec, 2012. http://tel.archives-ouvertes.fr/tel-00765458.
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Advanced mobile communication systems are characterized by a dense deployment of different types of wireless access points. Since these systems are primarily limited by interference, multiple-input multiple-output (MIMO) techniques as well as coordinated transmission and detection schemes are necessary to mitigate this limitation. Thus, mobile communication systems become more complex which requires that also the mathematical tools for their theoretical analysis must evolve. These must be able to take the most important system characteristics into account, such as fading, path loss, and interference. The aim of this thesis is to develop such tools based on large random matrix theory and to demonstrate their usefulness with the help of several practical applications, such as the performance analysis of network MIMO and large-scale MIMO systems, the design of low-complexity polynomial expansion detectors, and the study of random beamforming techniques as well as multi-hop relay and double-scattering channels. The methods developed in this work provide deterministic approximations of the system performance which become arbitrarily tight in the large system regime with an unlimited number of transmitting and receiving devices. This leads in many cases to simple and close approximations of the finite-size system performance and allows one to draw relevant conclusions about the most significant parameters. One can think of these methods as a way to provide a deterministic abstraction of the physical layer which substantially reduces the system complexity. Due to this complexity reduction, it is possible to carry out a system optimization which would be otherwise intractable.
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Tao, Meixia. "Space-time coding schemes for wireless communications over flat fading channels /." View Abstract or Full-Text, 2003. http://library.ust.hk/cgi/db/thesis.pl?ELEC%202003%20TAO.
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Thesis (Ph. D.)--Hong Kong University of Science and Technology, 2003.<br>Includes bibliographical references (leaves 111-118). Also available in electronic version. Access restricted to campus users.
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Mitchell, Jerry Roger. "Adaptive signal subspace digital receivers for communication in time-varying noise." Thesis, This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-06232009-063027/.
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Johnson, Stacey. "Feminist practice and the problem of "objectivity" : techniques of observation for communications studies." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=68107.
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The thesis examines the problems of the "observer" and "objectivity." I review Thomas Kuhn's concept of "paradigm shift" in order to access wider debates in the history and philosophy of science concerning epistemological development. I argue against traditional notions of "objectivity" and "rationality" that proceed to "naturalize" the binary opposition between the natural sciences and other intellectual pursuits. To make this argument I draw from feminist critics of science, including Sandra Harding, Evelyn Fox Keller, and Donna Haraway, who reconsider more palpable conceptions of "objectivity" and "rationality" for a feminist science project.<br>Jonathan Crary's revisionist, and non-linear approach to a history of vision and the modern observer suggests that feminist critiques of science represent an epistemological shift imperfectly constituted in the nineteenth century. In conclusion, I analyze Donna Haraway's multi-dimensional approach to cultural, and feminist theory as a visual metaphor that resonates with the nineteenth-century technology of the stereoscope.
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Holliday, Linda Ann. "Knowledge convergence theory the role of knowledge transfer in a corporate transformation /." Full text available, 1997. http://images.lib.monash.edu.au/ts/theses/holliday.pdf.
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Long, Eric M. "Decision-aided sequential sequence estimation for intersymbol interference channels." Diss., Georgia Institute of Technology, 1989. http://hdl.handle.net/1853/15019.
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Furbeck, David S. "Fast determination of bit error rates on impulsive noise channels." Diss., Georgia Institute of Technology, 1995. http://hdl.handle.net/1853/15656.
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McNary, Erin L. "Using the social cognitive theory of mass communication an examination of article and photographic content of a youth sport magazine from 1989-2008 /." [Bloomington, Ind.] : Indiana University, 2009. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3380111.
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Thesis (Ph.D.)--Indiana University, School of Health, Physical Education, and Recreation, 2009.<br>Title from PDF t.p. (viewed on Jul 14, 2010). Source: Dissertation Abstracts International, Volume: 70-12, Section: A, page: 4508. Adviser: Paul M. Pedersen.
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Strand, Karen. "Applying Public Relations Theory to Assess Service-Learning Relationships." Thesis, University of South Florida, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=1554008.
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<p> In Service-Learning (S-L) partnerships, universities and community organizations exchange resources and influence. Community engagement scholars Cruz and Giles proposed that relationships within S-L partnerships serve as units of analysis for the study of community outcomes of engagement. Yet, the scholarship of engagement lacks a suitable instrument to assess such relationships. This study brings together two lines of scholarship-relationship studies within community engagement and cocreational studies within public relations-to address the problem of assessing the community outcomes of S-L relationships, and it applies Cruz and Giles' ideas about using relationship analysis to assess community outcomes when it considers the perspectives of representatives of nonprofit organizations relative to their relationships with S-L students. Specifically, this qualitative study applies public relations theory to the problem of assessing project-based S-L relationships.</p>
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Mower, Jordan Todd. "Protecting Professional Football: A Case Study of Crisis Communication Tactics Demonstrated During the Concussion Crisis by the National Football League and the Introduction of Cultural Ingrainment as a Component in Crisis Communications Models." BYU ScholarsArchive, 2015. https://scholarsarchive.byu.edu/etd/5791.
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This research analyzes the crisis communications tactics employed by the National Football League at key points during the concussion crisis in relation to strategies recommended by models based on image restoration theory and situational crisis communications theory. The discrepancies between the NFL's tactics and recommended situational tactics, viewed in light of the financial and market increases for the league over the duration of the crisis, show the need for an additional component in accepted crisis communications models. Cultural ingrainment is posited as a component to be added to present models as a mitigating factor of organizational harm in cases of strong attribution of organizational responsibility. This addition of cultural ingrainment provides an explanation for the possibility of so-called “invincible brands.”
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Thanji, Faith Muthoni. "The use of emotion in health related messages: employing the exemplification theory to explain the MMR-autism debate." Thesis, Kansas State University, 2015. http://hdl.handle.net/2097/20388.
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Master of Science<br>Journalism and Mass Communications<br>Curtis B. Matthews<br>Health communication messages have been found to have a significant positive impact on audiences. However, numerous situations exist in which the general population is exposed to information from non-credible sources. This initial exposure can often bias or impact subsequent searching for more information.
Vaccinations have been considered effective as a result of the number of lives that have been saved by preventing life threatening diseases. However there is also a growing group of anti-vaccine sources. The rise of the internet has resulted in the growth of numerous unqualified anti-vaccine sources.
Nearly 70% of the health information that people find on the internet is from non-credible sources. These messages often take the form of videos in which a person who makes a passionate claim about the side effects of vaccines uses personal experiences (exemplars). These exemplars are used to counter the volumes of scientific and clinical research which show the effectiveness of vaccinations (base-rate information).
This study manipulates the usage of passionate and dispassionate exemplars and base-rate information by simulating a real-world situation. Passionate exemplars were the most likely to create fear in our audience. Increasing the passion of our base-rate presenters exhibited both positive and negative side effects.
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Matthews, Tami J. "Disaster Communication Networks: A Case Study of the Thai Red Cross and Their Disaster Communication Response to the Asian Tsunami." BYU ScholarsArchive, 2006. https://scholarsarchive.byu.edu/etd/1091.
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Disaster victims and vulnerable populations are audiences that communications professionals and scholars have ignored. Public relation practices dominate current disaster communication policy. This study examines the disaster communication network, including policy and practice, of the Thai Red Cross, before, during, and after the Asian tsunami. Disaster communication(s) is defined as the sharing and exchange of information with the victims immediately affected by a disaster. This definition focuses specifically on the vulnerable audience and allows response efforts to emerge from multiple disciplines. Focusing response efforts on victims' assessed needs and abilities allows for a multi-disciplinary approach to mitigate further suffering. The disciplines of health, development, and communications converge for efficient disaster management. This case study gives great insight into the cultural chasm between policy making and practical application and also reveals the value of personal initiative. A proposed model of disaster communication is offered. Significantly more research is needed in the area of disaster communications.
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Rondeau, Thomas Warren. "Application of Artificial Intelligence to Wireless Communications." Diss., Virginia Tech, 2007. http://hdl.handle.net/10919/29199.
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This dissertation provides the theory, design, and implementation of a cognitive engine, the enabling technology of cognitive radio. A cognitive radio is a wireless communications device capable of sensing the environment and making decisions on how to use the available radio resources to enable communications with a certain quality of service. The cognitive engine, the intelligent system behind the cognitive radio, combines sensing, learning, and optimization algorithms to control and adapt the radio system from the physical layer and up the communication stack. The cognitive engine presented here provides a general framework to build and test cognitive engine algorithms and components such as sensing technology, optimization routines, and learning algorithms. The cognitive engine platform allows easy development of new components and algorithms to enhance the cognitive radio capabilities. It is shown in this dissertation that the platform can easily be used on a simulation system and then moved to a real radio system.
The dissertation includes discussions of both theory and implementation of the cognitive engine. The need for and implementation of all of the cognitive components is strongly featured as well as the specific issues related to the development of algorithms for cognitive radio behavior. The discussion of the theory focuses largely on developing the optimization space to intelligently and successfully design waveforms for particular quality of service needs under given environmental conditions. The analysis develops the problem into a multi-objective optimization process to optimize and trade-of of services between objectives that measure performance, such as bit error rate, data rate, and power consumption. The discussion of the multi-objective optimization provides the foundation for the analysis of radio systems in this respect, and through this, methods and considerations for future developments. The theoretical work also investigates the use of learning to enhance the cognitive engine's capabilities through feed-back, learning, and knowledge representation.
The results of this work include the analysis of cognitive radio design and implementation and the functional cognitive engine that is shown to work in both simulation and on-line experiments. Throughout, examples and explanations of building and interfacing cognitive components to the cognitive engine enable the use and extension of the cognitive engine for future work.<br>Ph. D.