While developing modern applications, it is necessary to ensure an efficient and performant communication between different applications. In current environments, a middleware software is used, which supports the publish/subscribe communication pattern. Using this communication pattern, a publisher sends information encapsulated in messages to the middleware. A subscriber registers its interests at the middleware. The monograph describes three different steps to determine the performance of such a system. In a first step, the message throughput performance of a publish/subscribe in different scenarios is measured using a Java Message Service (JMS) based implementation. In the second step the maximum achievable message throughput is described by adapted models depending on the filter complexity and the replication grade. Using the model, the performance characteristics of a specific system in a given scenario can be determined. These numbers are used for the queuing model described in the third part of the thesis, which supports the dimensioning of a system in realistic scenarios. Additionally, we introduce a method to approximate an M/G/1 system numerically in an efficient way, which can be used for real time analysis to predict the expected performance in a certain scenario. Finally, the analytical model is used to investigate different possibilities to ensure the scalability of the maximum achievable message throughput of the overall system. / Bei der Entwicklung moderner Applikationen ist es notwendig eine effiziente und performante Kommunikation zwischen den einzelnen Anwendungen sicherzustellen. In der Praxis kommt dabei eine Middleware Software zum Einsatz, die das Publish/Subscribe Kommunikationsmuster unterstützt. Dabei senden Publisher Informationen in Form von Nachrichten an die Middleware. Die Subscriber hingegen zeigen durch die Nutzung von Filtern der Middleware an, welche Informationen zugestellt werden sollen. Die Arbeit beschreibt ein dreistufiges Verfahren zur Leistungsbestimmung eines solchen Systems. Zunächst wird durch Messung die Leistung von Publish/Subscribe Systemen in verschiedenen Szenarien untersucht am Beispiel von Java Message Service (JMS) basierten Implementierungen. Danach wird der maximale Nachrichtendurchsatz in Abhängigkeit der Filterkomplexität und des Nachrichtenreplikationsgrades durch einfache Modelle beschrieben. Damit können die Leistungskennwerte für ein System und vorgegebenen Randbedingungen beschrieben werden. Im dritten Teil wird mittels Leistungsbewertung und durch Anwendung eines Warteschlangenmodells die Leistung in praxisnahen Umfeld beschrieben, so dass eine Dimensionierung möglich wird. Zusätzlich wird ein mathematisch, approximatives Verfahren vorgestellt, um ein M/G/1 System numerisch effizient berechnen zu können, was bei der Echtzeitbewertung eines Systems zur Leistungsvorhersage benutzt werden kann. Des Weiteren werden mittels des Modells Möglichkeiten untersucht die Skalierbarkeit des Gesamtsystems in Bezug auf den Nachrichtendurchsatz sicherzustellen.

Message credibility is a commonly used term to indicate how well the recipients approve the message. Source credibility, on the other hand is a “communicator's positive characteristics that affect the receiver's acceptance of a message” (Ohanian, 1990, pp 41). It has been stated that an effect is apparent between the two, therefore the purpose of this study is to describe the effect of source credibility characteristics; trustworthiness, expertise and attractiveness on message credibility. The study utilized a quantitative research approach in order to describe the effect between the concepts. The researchers used a Likert-scale online questionnaire as the data collection method. The findings of this research suggest that all of the characteristics within the source credibility model are proven to have a significant and positive effect on the message credibility.

Magister Artium - MA / This research uses the Systemic Functional Linguistics (SFL) approach, more specifically, the appraisal theory to analyse the online message postings by fans of the popular music artist, Beyoncé Knowles. Through their online writings, insight into their evaluative discourses is gained. This research focuses on the emotional, judgemental and evaluative stance in their writings, especially; the linguistic choices that the online fans use in order to convey their attitudes: appreciation and judgement and affect towards Knowles. In order to do such an analysis, the study considers the different Systemic Functional Linguistic (SFL) levels of meaning (interpersonal, textual and experiential metafunctions). Several questions become pertinent: What kinds of interpersonal relations and identities are implicated on the message boards? (Interpersonal metafunction). How are these expressed textually? (Textual metafunction). What kinds of experiences/fields are implicated in the messages? (Experiential metafunction). The research concludes that in terms of identity, fans tend to latch onto a Hip-Hop culture in order to create and maintain a connection to Knowles. Fans display this linguistically by writing certain words out phonetically as they would be pronounced orally. Gender boundaries are transgressed irrespective of the fans' gender. Posts also demonstrate colourful expressive responses in relation to Knowles. Whether the fan is male or female, both feel comfortable in using emotive language to demonstrate the impact which she has on their lives. In terms of appreciation fans tend to express that she has inspired and changed their lives. Attitudes explored demonstrated that a number of Knowles' fans hold positive viewpoints and therefore they would align themselves positively towards her. The element of judgement was explored from different perspectives in relation to Knowles. One, being a website which suggested that Knowles had undergone an evil transformation. For evidence, these fans used her lyrics, gestures and images selectively as a way to "prove" their arguments. As a contribution to knowledge, this research is useful in the sense that when individuals log online and leave their posts on message boards, they do not always realise the impact of the message that they leave behind. Using SFL and the appraisal theory, one is able to establish the attitudes: judgements, appreciation and affect individuals hold towards a particular topic or person (in this case towards Knowles). Through linguistically analysing message boards, one is able to connect individuals to possible identity options. In essence, the letters and words which individuals have strung together create a greater picture than what was possibly intended. Linguistically, it opens more avenues for exploration.

This research adds the growing body of literature on the role of celebrities as emergent spokespersons in climate advocacy and the process and consequences of its effects on public attitudes and behaviors to resolve the climate crisis. By applying social cognitive theory in conjunction with emotional appeals and language styles as message frames, the study examines the effects of role-modeling in adoption of eco-attitudes and behaviors. In a 2 x 2 design, the independent variables were emotion frame (fear, hope) and celebrity involvement frame (first person pronouns; FPP, non-first person pronouns; NFPP). For the manipulation check, the tweets were pilot tested. The main study was an experiment that asked participants to read tweets attributed to Leonardo DiCaprio or Pharrell Williams. Four main dependent variables were attitudes toward climate change mitigation and three behaviors, including support for government action, intention to engage in sustainable behavior, and intention to participate in activism for climate change mitigation. The role of two mediating variables (risk awareness, response efficacy) and one moderating variable, parasocial interaction (PSI) with the celebrity, were also examined. First, one-way ANCOVAs compared the effects of emotion frames to the control group. No evidence of the effects of emotion frame over unrelated messages on any dependent variables was found. Second, 2 (fear vs hope) x 2 (FPP vs NFPP) ANCOVAs found that fear-framed messages were more effective than hope-framed messages in driving intention for participation in activism, but emotion frame did not affect any other variables. The results also found that FPP frames led to more positive attitude (compared to NFPP frames), but had no effect on behaviors. Third, regression analyses found no evidence that risk awareness or response efficacy mediated the effect of emotion frames on attitudes or behaviors. In addition, the study discovered that PSI was a strong positive predictor of attitudes and all behaviors, but PSI did not moderate the impact of the celebrity involvement frame. The findings provide empirical evidence of the potential for celebrities to serve as role models in climate advocacy by psychologically involving people, which can be translated to the adoption of attitudes and behaviors.

<p>Problem: What type of messages can be used to make ‘saving the environment’ more appealing to individuals, in order to encourage them to act environmentally friendly?</p><p>Purpose: Our focus is the challenge of convincing consumers to save electricity in the Netherlands. Using two different types of messages, environmental and financial, our aim is to identify which characteristics of marketing messages are more effective when trying to encourage individuals to act environmentally friendly.</p><p>Method: Interviews with relevant organizations are held in order to see what professionals say about the environment and marketing. Questionnaires are distributed to see what the general opinion is and finally a case study is conducted to investigate the effectiveness of several messages on people’s electricity consumption.</p><p>Conceptual Framework: The theory of social marketing is being used, derived from nonprofit marketing. A communication model is applied to the findings, just as the concept of mental accounting.</p><p>Conclusion: Our research showed a clear preference for rational based messages that provide benefit claims, that are one sided messages, which are positively framed, focusing on the personal benefits resulting from the change in behavior and finally people should be able to draw conclusions on their own, but they should be given enough directions in the message to draw their conclusion.</p>

Development of highly intelligent computers requires a conceptual foundation that will overcome the limitations of the von Neumann architecture. Architectures for such a foundation should meet the following design goals: * Address the fundamental organizational issues of large-scale parallelism and sharing in a fully integrated way. This means attention to organizational principles, as well as hardware and software. * Serve as an experimental apparatus for testing large-scale artificial intelligence systems. * Explore the feasibility of an architecture based on abstractions, which serve as natural computational primitives for parallel processing. Such abstractions should be logically independent of their software and hardware host implementations. In this paper we lay out some of the fundamental design issues in parallel architectures for Artificial Intelligence, delineate limitations of previous parallel architectures, and outline a new approach that we are pursuing.

The debate about how to frame health messages to maximize their effectiveness is ongoing. Research supports the use of both positive and negative frames under different conditions. This project was developed to further clarify the circumstances under which a negative frame may be harmful, or even backfire. In Study 1 it was proposed that past drinking behavior would moderate the relationship between message frame and behavioral intention to drink alcohol in the future such that people with a heavy drinking past would react to a negatively framed message by increasing their intention to consume alcohol. A total of 212 students participated in the study where they completed a questionnaire to provide information on some of the key variables, such as drinking history, and then were asked to read mock health materials with either a positive or negative frame. They concluded the study by responding to a final questionnaire where they provided feedback on the health materials and indicated their intentions to drink in the future. Results of this study supported the hypothesis. The goals of Study 2 were to replicate the findings of Study 1 and to test the hypothesis that self-esteem would be a second-order moderator of this effect such that people with a heavy drinking past and high self-esteem would be most likely to respond to a negatively framed message by increasing their intention to drink alcohol in the future. A total of 490 students participated in the study, which followed the same procedure as the first study. Results of Study 2 failed to replicate the findings from Study 1, and indicated that self-esteem did influence the relationship between past behavior, message frame and behavioral intention but not in the proposed direction. The marginally-significant effect found in Study 2 suggested that heavy drinkers with high self-esteem were actually more likely to decrease their intentions to drink alcohol after reading a negatively framed message. Because of the inconsistency in the results of the two studies presented, proposed directions for future research are discussed.

Problem: What type of messages can be used to make ‘saving the environment’ more appealing to individuals, in order to encourage them to act environmentally friendly? Purpose: Our focus is the challenge of convincing consumers to save electricity in the Netherlands. Using two different types of messages, environmental and financial, our aim is to identify which characteristics of marketing messages are more effective when trying to encourage individuals to act environmentally friendly. Method: Interviews with relevant organizations are held in order to see what professionals say about the environment and marketing. Questionnaires are distributed to see what the general opinion is and finally a case study is conducted to investigate the effectiveness of several messages on people’s electricity consumption. Conceptual Framework: The theory of social marketing is being used, derived from nonprofit marketing. A communication model is applied to the findings, just as the concept of mental accounting. Conclusion: Our research showed a clear preference for rational based messages that provide benefit claims, that are one sided messages, which are positively framed, focusing on the personal benefits resulting from the change in behavior and finally people should be able to draw conclusions on their own, but they should be given enough directions in the message to draw their conclusion.

Le Vietnam, tout comme les autres pays asiatiques en voie de développement, dans son processus de transition vers une économie de marché, utilise la publicité comme moyen important de s'intégrer à l'économie de marché et ultimement, de s'intégrer à l'économie mondiale (Frith, 1998). C'est dans ce contexte que nous avons souhaité étudier la question de la diversité des valeurs culturelles présentes dans les publicités vietnamiennes. Afin de réaliser cet objectif de recherche, nous avons mené deux études visant à évaluer dans quelle mesure la publicité s'harmonise aux valeurs culturelles du Vietnam. La première étude a consisté en l'analyse de contenu afin de comprendre l'utilisation des valeurs culturelles dans les publicités vietnamiennes actuelles. La seconde étude est basée sur des entrevues avec des agences publicitaires au Vietnam et a cherché à comprendre le point de vue, l'attitude et la stratégie de ces agences envers l'utilisation des valeurs culturelles dans la création publicitaire et ce, dans le contexte de diversité culturelle actuel dans la société vietnamienne. L'industrie de la publicité du Vietnam est jeune et en est encore dans ses premières phases de développement et, de plus, elle évolue dans un contexte de mondialisation. La diversité culturelle et surtout l'influence des forces étrangères, telles que les agences publicitaires et les firmes multinationales, sont considérables ce qui, incidemment, se reflète dans sa création publicitaire. Ce mémoire s'applique également à étudier les changements culturels au Vietnam. Nous avons pu observer une tendance au changement plus importante chez les jeunes générations par rapport aux autres segments de la population. Ainsi il y aurait une tendance d'adaptation entre les caractéristiques de la communication locale et le style créatif des agences publicitaires et firmes multinationales. ______________________________________________________________________________ MOTS-CLÉS DE L’AUTEUR : Vietnam, Publicité, Culture, Mondialisation, Développement.

We propose a formal model for non-interactive message authentication protocols (NIMAPs) using two channels and analyze all the attacks that can occur in this model. Further, we introduce the notion of hybrid-collision resistant (HCR) hash functions. This leads to a new proposal for a NIMAP based on HCR hash functions. This protocol is as efficient as the best previous NIMAP while having a very simple structure and not requiring any long strings to be authenticated ahead of time. We investigate interactive message authentication protocols (IMAPs) and propose a new IMAP, based on the existence of interactive-collision resistant (ICR) hash functions, a new notion of hash function security. The efficient and easy-to-use structure of our IMAP makes it very practical in real world ad hoc network scenarios. We also look at message recognition protocols (MRPs) and prove that there is a one-to-one correspondence between non-interactive MRPs and digital signature schemes with message recovery. Further, we look at an existing recognition protocol and point out its inability to recover in case of a specific adversarial disruption. We improve this protocol by suggesting a variant which is equipped with a resynchronization process. Moreover, another variant of the protocol is proposed which self-recovers in case of an intrusion. Finally, we propose a new design for message recognition in ad hoc networks which does not make use of hash chains. This new design uses random passwords that are being refreshed in each session, as opposed to precomputed elements of a hash chain.