Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Includes bibliographical references (leaves 86-91). Also available via the Internet.

Thesis (Ph. D.)--Illinois State University, 1994. / Title from title page screen, viewed April 18, 2006. Dissertation Committee: Rodney P. Riegle (chair), John R. McCarthy, Paul J. Baker, Jeffrey Hecht. Includes bibliographical references (leaves 71-75) and abstract. Also available in print.

Thesis (Ph. D.)--University of California, San Diego, 2006. / Title from first page of PDF file (viewed December 12, 2006). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 134-143).

How much damage can a malicious tiny device cause in a single-hopwireless network? Imagine two players, Alice and Bob, who want toexchange information. Collin, a malicious adversary, wants to preventthem from communicating. By broadcasting at the same time as Alice orBob, Collin can destroy their messages or overwhelm them with his ownmalicious data. Being a tiny device, however, Collin can onlybroadcast up to B times. Given that Alice and Bob do not knowB, and cannot distinguish honest from malicious messages, howlong can Collin prevent them from communicating? We show the answerto be 2B + Theta(lg|V|) communication rounds, where V is theset of values that Alice and Bob may transmit. We prove this resultto be optimal by deriving an algorithm that matches our lowerbound---even in the stronger case where Alice and Bob do not start thegame at the same time.We then argue that this specific 3-player game captures the generalextent to which a malicious adversary can disrupt coordination in asingle-hop wireless network. We support this claim by deriving---via reduction from the 3-player game---round complexity lower boundsfor several classical n-player problems: 2B + Theta(lg|V|) for reliable broadcast,2B + Omega(lg(n/k)) for leader election among k contenders,and 2B + Omega(k*lg(|V|/k)) for static k-selection. We then consider an extension of our adversary model that also includes up to t crash failures. We study binary consensus as the archetypal problem for this environment and show a bound of 2B + Theta(t) rounds. We conclude by providing tight, or nearly tight, upper bounds for all four problems. The new upper and lower bounds in this paper represent the first such results for a wireless network in which the adversary has the ability to disrupt communication.

Texte remanié de: Diss.--Theologische Fakultät--Universität Freiburg i. Br., Wintersemester 1998/99. / Bibliogr. p. 554-579. Index.

Στη παρούσα διπλωματική εργασία ασχολούμαστε με την ανάπτυξη τεχνικών για υλοποίηση ενός κατανεμημένου φίλτρου Kalman σε ένα Δίκτυο Αισθητήρων (WSN). Τα δίκτυα αυτά έχουν γνωρίσει τα τελευταία χρόνια ραγδαία ανάπτυξη λόγω των εξαιρετικά πολλών εφαρμογών τους σε διάφορα πεδία της ανθρώπινης δραστηριότητας. Το πρόβλημα που πραγματευόμαστε εδώ είναι η προσπάθεια εκτίμησης της κατάστασης μιας στοχαστικής διαδικασίας που επιτηρείται-παρακολουθείται απο το δίκτυο. Οι κόμβοι-αισθητήρες που συναπαρτίζουν αυτά τα δίκτυα έχουν συνήθως περιορίσμενες δυνατότητες ¨αίσθησης¨, πράγμα που σημαίνει ότι κάθε μεμονωμένος κόμβος αδυνατεί να παράξει μια καλή εκτίμηση της κατάστασης. Διάφορες τεχνικές εχούν προταθεί για την επίλυση τέτοιου είδους προβλημάτων όπως το κεντρικό Φίλτρο Kalman ή διάφορες αποκεντρωμένες προσεγγίσεις, οι οποιές είχαν όμως υψηλό υπολογιστικό κόστος και τις καθιστούσαν πρακτικά μη υλοποιήσιμες, ειδικά για δίκτυα με μεγάλο αριθμό κόμβων. Έτσι στη παρούσα εργασία , χρησιμοποιώντας ως εργαλείο την θεώρια των αλγορίθμων ¨Κοινής Συμφωνίας¨ (Consensus Algorithms) , κατασκευάζουμε Αλγορίθμους χαμήλης πολυπλοκότητας, για την υλοποίηση ενός Kατανεμημένου Φίλτρου Kalman, θεωρώντας ότι όλοι οι κόμβοι είναι ομότιμοι (peer-to-peer αρχιτεκτονικές), κάθε κόμβος επικοινωνεί μόνο με τους γειτονικούς του και δεν υπάρχουν Fusion Centers. Παρουσιάζουμε έτσι τρεις διαφορετικούς επαναληπτικούς αλγορίθμους βασιζομένων σε δύο διαφορετικές λογικές και τέλος προσομοιώνουμε και αξιολογούμε την επίδοση καθενός από αυτούς. / In this thesis we deal with the development of techniques for implementing a distributed Kalman filter in a sensor network (WSN). Ιn recent years these networks have experienced rapid growth, due to the numerous applications in various fields of human activity. The problem we discuss here is the attempt to estimate the state of a stochastic process which is monitored by nodes-sensors. The nodes that constitute these networks usually have limited “sense” capabilities, which means that each node is unable to produce a good estimate of the state, using only its own measurements. Various techniques have been proposed to solve this kind of problems, such as the Central Kalman Filter or several decentralized approaches, which did have a high computational cost that renders them impractical, especially for networks with a high number of nodes. Thus, in the present work, , we construct low complexity algorithms for the implementation of a Distirbuted Kalman Filter, using as a tool the theory of Consensus Algorithms and assuming that all nodes are peers (peer-to-peer architectures), each node communicates only with its neighboring and no Fusion Centers exist. Τhus, we present three different iterative algorithms based on two different approaches and finally simulate and evaluate the performance of each of them.

Purpose – In the context of digitalization in healthcare and Swedish demographical development, the importance of meta-organizational decision-making can be discussed. This paper studies the decision-making processes in a national meta-organization which members face the current challenges of Swedish public healthcare. Therefore, this paper aims to contribute to meta-organizational decision-making. Design/methodology/approach – This paper has a qualitative approach and is based in abductive reasoning towards theory and research. Data has been collected from interviews, podcasts and documents that describe the decision-making process in the meta-organization. Findings – Our empirical findings show that the decision-making process of the metaorganization is complex, time-consuming and aims to provide consensus before its members' decisions. To reach consensus, the meta-organization uses various coordination and collaboration activities and groupings such as networks, workshops, expert panels, and conferences. Practical implications – Both informal and formal activities and groupings are considered important in reaching consensus. Furthermore, both formal and informal groupings help to overcome interest-conflicts such as differing priorities. It is also important the metaorganization provide an arena where all members feel that the can contribute and influence the decision-making process, regardless of size or resources. Originality/value – Because of dichotomic views on the importance of consensus in decision-making in meta-organization, and from calls for future research, this study can be argued to be of interest. Furthermore, digitalization and demographical development suggest that the healthcare sector is in current and significant change. Keywords – decision-making, meta-organizations, digitalization, demographics, healthcare, coordination, interest-conflict, consensus Paper type – Research paper, master's thesis

abstract: Native American communities face an ongoing challenge of effectively addressing cancer health disparities, as well as environmental racism issues that may compound these inequities. This dissertation identified the shared cultural knowledge and beliefs about cancer in a southwest American Indian community utilizing a cultural consensus method, an approach that combines qualitative and quantitative data. A community-based participatory research (CBPR) approach was applied at all stages of the study. The three phases of research that were undertaken included: 1) ethnographic interviews - to identifying the themes or the content of the participants' cultural model, 2A) ranking of themes - to provide an understanding of the relative importance of the content of the cultural model, 2B) pile sorts - identify the organization of items within specific domains, and 3) a community survey - access whether the model is shared in the greater community. The cultural consensus method has not been utilized to date in identifying the collective cultural beliefs about cancer prevention, treatment or survivorship in a Native American community. Its use represents a methodological step forward in two areas: 1) the traditional ethnographic inferences used in identifying and defining cultural meaning as it relates to health can be tested more rigorously than in the past, and 2) it addresses the challenge of providing reliable results based on a small number of community informants. This is especially significant when working with smaller tribal/cultural groups where the small sample size has led to questions concerning the reliability and validity of health-related research. Results showed that the key consultants shared strong agreement or consensus on a cultural model regarding the importance of environmental and lifestyle causes of cancer. However, there was no consensus found among the key consultants on the prevention and treatment of cancer. The results of the community survey indicated agreement or consensus in the sub-domains of descriptions of cancer, risk/cause, prevention, treatment, remission/cure and living with cancer. Identifying cultural beliefs and models regarding cancer could contribute to the effective development of culturally responsive cancer prevention education and treatment programs. / Dissertation/Thesis / Ph.D. Anthropology 2011

The purpose of this research study is to expand upon the body of knowledge and research regarding the conditions and processes for effective decision-making in virtual team environments. Specifically, this study sought to demonstrate that teams instructed in consensus produce higher quality decisions and attain the assembly effect (synergy) on complex decision tasks. In addition, teams in virtual communication environments will produce higher quality decisions and attain the assembly effect (synergistic decisions) less often than face-to-face teams on complex decision tasks. Mostly undergraduate students from business courses (N = 358) completed the NASA Survival Exercise complex decision task first individually, then as teams. Subjects were randomly assigned to teams; teams were randomly assigned to one of two decision mode conditions: i) instructed in the consensus decision technique; and ii) not-instructed in the consensus decision technique. Subjects were then randomly assigned to one of three communication mode environments: i) face-to-face; ii) instant messaging; and iii) videoconferencing. A 2 X 3 between-subjects factorial design was used to examine the research questions. The hypotheses compared several mean decision performance measures for three and four-person teams (n = 105) differing in decision mode (consensus instructed vs. not-instructed) and differing in communication mode (face-to-face) or one of two virtual communication environments (instant messaging or videoconferencing). Hypotheses for the decision mode main effect, the communication mode main effect and the interaction effect were not statistically significant. However, the decision performance measure means for communication mode and the interaction between communication mode and the decision mode were in the predicted direction. Future research is needed to clarify the influence of consensus instruction and technology-mediated communication environments on virtual teams.

Made available in DSpace on 2009-11-18T19:00:51Z (GMT). No. of bitstreams: 1 rosanaroal.pdf: 564383 bytes, checksum: 3fde0a8704d147b75e045309c621d576 (MD5) Previous issue date: 2009 / The main subject of this study is the consensus analysis of negotiations of Regional Trade Agreements (RTAs). Generally speaking, delays and interruptions caused by controversies and impasses end up becoming strong efficiency problems which jeopardize the consensus building during any negotiation. As a justification, the target of this study is to identify processes to help obtain, efficiently, agreements in the RTAs negotiations. Its final objective was to search for theoretical tools and techniques to be applied in situations of stoppage in a sense of eliminating the difficulties or making them at least easier to deal with. Secondarily other theoretical points of view were considered with the intention of understanding how strategies and theoretical tools can contribute in each/or different scenario of the negotiation. Through the different ways of looking at it for the conduction of the negotiations, for evaluating the dimensions of the negotiations and in order to build up the consensus, the researcher was able to understand the perception and the interpretation of the subject in view. At last the conclusion was that the applicability of the chosen framework is positive in helping solve problems and controversies as well as building up the consensus during the negotiations. / Esse trabalho aborda como tema principal o estudo da construção de consenso em negociações de Acordos Regionais de Comércio (ARCs). Nas negociações em geral, atrasos e paralisações, ocasionados por controvérsias e impasses, podem constituir um forte problema de eficiência na construção de consenso. Como justificativa, diante da problemática, esse trabalho visa identificar processos que auxiliem a obter, eficientemente, acordos nas negociações. Seu objetivo final foi a busca por instrumentos teóricos e técnicas que pudessem ser aplicados em situações de paralisações, no sentido de eliminá-las ou amenizá-las. Como objetivo secundário, foram estudadas outras abordagens teóricas no intuito de entender, sob diversas óticas, como estratégias e instrumentos teóricos contribuem mais eficientemente em certas situações e/ou negociações. Através das diferentes abordagens escolhidas para avaliação das dimensões presentes nas negociações e para construção de consenso, ficou possível ao pesquisador a percepção e interpretação do fenômeno estudado. Ao final, concluiu-se positivamente sobre a aplicabilidade do arcabouço teórico escolhido, no auxílio na solução problemas de controvérsias e impasses, bem como, na construção de consenso nas negociações.