The current Internet presents a high barrier to entry for new service providers, due to its inability to accommodate new protocols and technologies, and lack of competition among the network providers. Recently, network virtualization has gained considerable attention as a possible solution, as it enables multiple networks to concurrently run over a shared substrate. It allows for deploying diverse network protocols and technologies customized for specific networked services and applications. Moreover, any party can take on the role of a network provider by simply offering his virtual network infrastructure to customers, increasing competition in the market. However, the first challenge in realizing a fair and competitive market in a virtual network environment is to have a service negotiation and contracting mechanism in place, that will allow (i) multiple infrastructure providers to participate in a fair and faithful competition, and (ii) a service provider to negotiate the price and quality of service with the providers. In this thesis, we present V-Mart, an open market model and enabling framework for automated service negotiation and contracting in a virtual network environment. To the infrastructure providers, V-Mart fosters an open and fair competition realized by a two stage auction. The V-Mart auction model ensures that bidders (infrastructure providers) bid truthfully, have the flexibility to apply diverse pricing policies, and still gain profit from hosting customers’ virtual resources. To the service providers, V-Mart offers virtual network partitioning algorithms that allow them to divide their virtual networks among competing infrastructure providers while minimizing the total cost. V-Mart offers two types of algorithms to suit different market scenarios. The algorithms not only consider virtual resource hosting price but also the service provider’s preference for resource co-location and the high cost of inter-provider communication. Through extensive simulation experiments we show the efficiency and effectiveness of the algorithms under various market conditions.

The use of Facebook is increasing rapidly and its pedagogical uses are endless. University students are part of a new generation, working with ease and confidence in this social environment. This article explores the use of Facebook as an additional communication tool in an undergraduate taxation module presented at the University of Pretoria and evaluates students’ perceptions of the effectiveness of such a tool. A Facebook group was created to enhance interaction between students and lecturers and students and their peers. Participation was voluntary, and the students completed a survey at the end of the semester to evaluate their experience in the group. The results of the study show that, although the use of a Facebook group as a communication tool cannot replace the formal learning management system of the university, respondents’ perception of the use of the tool was that Facebook could be used as an additional academic communication tool in all of their subjects. It is the lecturers’ responsibility to learn how to use this tool and incorporate it effectively into their teaching strategies. Copyright 2012, University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. Please cite as follows: Hill, T 2012, Facebook as a tool for communication with under graduate taxation students, MCom dissertation, University of Pretoria, Pretoria, viewed yymmdd < http://upetd.up.ac.za/thesis/available/etd-03092012-111246 / > F12/4/166/gm / Dissertation (MCom)--University of Pretoria, 2012. / Taxation / MCom / Unrestricted

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Computer networks are continuously evolving and growing in size and complexity. New technologies are being introduced which further increases the complexity. Net- work Service Orchestration is all about pushing configuration out into the network devices automatically without human intervention. There can be issues that causes the orchestration to fail. In many cases manual operations must be done to recover from the error which is very contradicting since the goal of orchestration is that it should be fully automated. There is some indication that the errors that are being solved manually could be de- tected and handled by a feedback mechanism. This thesis work aimed to build on current insight and if possible, verify that the feedback mechanism is a viable method. After consideration on different ways to solve the research question, the choice fell on creating a test environment where the approach was tested. The test environment was used to investigate if a network orchestration system could be integrated with a feedback mechanism. The result of this project presents a way to automatically de- tect a network failure and send feedback to a Network Service Orchestrator. The or- chestrator is then able to identify and correct the error. / Datornätverk utvecklas kontinuerligt och växer i storlek och komplexitet. Nyteknik införs som ytterligare ökar komplexiteten. Nätverksservice orkestrering handlar om att skicka ut konfiguration automatiskt till enheter i nätverket utan mänsklig in- blandning. Det kan finnas problem som gör att orkestreringen misslyckas. I många fall måste manuella åtgärder utföras för att lösa problemet, vilket är mycket motsä- gelsefullt, eftersom målet med orkestrering är att det ska vara fullt automatiserat. Det finns indikationer på att fel kan detekteras och hanteras av en återkopplings- mekanismen. Detta examensarbete syftar till att bygga på aktuell insikt, och om möj- ligt, verifiera att återkopplingsmekanismen är en möjlig metod. Efter överväganden på vilka olika sätt som projektmålet kunde uppnås föll valet på att skapa en testmiljö där ansatsen kunde testas. Testmiljön användes för att utreda om ett nätverksorkestreringssystem kan integreras med en återkopplings mekanism. Resultat av projektet presenterar ett sätt att automatiskt upptäcka ett nätverksfel och skicka återkoppling till ett nätverksorkestreringssystem. Nätverksorkestreraren kan sedan detektera och åtgärda felet.

The rapid developments Social Network Service (SNS) have offered opportunities to re-visit many seminal theoretical assumptions of technology usage within socio-technical environment. Online social network is a rapidly growing field that imposes new questions to the existing IS research paradigm. It is argued that information systems research must necessarily evolve in response to the emerging trends (Lyytinen and King, 2004). Specifically, one stream of research has been heavily lacking is SNS usage prediction (Hargittai, 2007). In SNS, the form of social network is realized by computing networks where the individual assumes an identity of an “avatar”. People are merging their activities of work and living thus blurring the borders among their social contexts (Beck and Wade, 2006). Such new trends have become more sophisticated due to the increasingly robust data network capacity and pervasive availability of communication technology. At present, research in SNS is still in its early stage; hence the need to develop knowledge of virtual world dynamics has become impending. SNS essentially provides various service channels to facilitate social network interactions. These channels are highly correlated with their respective service contexts, among which differences are obvious and important. Cultural factors have been crucial for context oriented studies in both IS and sociology fields. For instance, the global nature of the Internet “raises questions about the robustness of trust effects across cultures” (Jarvenpaa et al., 1999). In SNS, not only trust but also privacy has become a tremendous caveat for service providers. Investigating the combination effects of privacy and trust in a cross-cultural study may lead to important theoretical discoveries and meaningful managerial implications. This study contributes to knowledge by empirically testing established theoretical models of IS acceptance, trust, social and cultural research. Both qualitative and quantitative methods are used in order to present a comprehensive analysis of SNS perception and use in different cultural settings. Particularly, the study finds critical differences exist within the process of trust formulation between American and Chinese SNS users.

Les réseaux de capteurs sans fils (WSN) ont connu un succès important ces dernières années, en particulier grâce à l’émergence de l’Internet des Objets (IoT), qui a permis des applications beaucoup plus intéressantes. Les réseaux de capteurs sont utilisés dans presque toutes les applications de maisons et villes intelligentes et des objets connectés personnels. Beaucoup de ces applications nécessitent que les nœuds de capteurs constituant le réseau soient autonomes et donc efficaces en énergie. Le thème de l'efficacité énergétique pour les WSN est riche et adressé par de nombreuses équipes de recherches. L'une des solutions les plus prometteuses est l'intégration de blocs adaptatifs dans le nœud, qui peuvent ajuster leurs performances et leurs dépenses énergétiques selon les besoins de l'application, son environnement ou l’énergie disponible. L’objectif est de permettre à un nœud de fonctionner à un point d'énergie optimal et d'atteindre l'efficacité énergétique la plus élevée possible. Le travail présenté dans cette thèse traite du contrôle de ces blocs adaptatifs. Un nœud de WSN doit être capable de se réveiller et de se remettre en veille rapidement ce qui impose l'utilisation d'un réseau de contrôle efficace. Les données de contrôle peuvent être analogiques ou numériques. Ceci entraîne le besoin d'un réseau de communication complémentaire au réseau qui sert à transmettre les données numériques. Dans ce travail, un premier réseau de communication asynchrone est proposé pour adresser ce besoin de transfert de données de configuration dans un nœud. Cette communication basée sur événement utilise la logique asynchrone QDI. Ce premier réseau est numérique et deux versions ont été conçues, une série et une hybride. La version série a été implémentée en silicium et testée. Les deux se sont avérées efficaces en énergie ; le réseau série n’utilise que 1pJ/bit, tandis que l'hybride consomme 0,07pJ/bit à 0.6V en technologie FDSOI de 28nm.Dans la deuxième partie de ce travail, une amélioration visant des circuits plus simples et mixtes a été réalisée, incluant la conception et l'analyse d'un réseau capable de transférer efficacement des données analogiques. / Wireless sensor network (WSN) have experienced an incredible success these past years, especially due to the Internet of Thing (IoT) paradigm, which opened the door to much more interesting applications. The wireless sensor network nodes (WSNN) are used in nearly all smart houses applications, as a network of wearables or as entertainment devices. This keen interest in WSN is not without consequences, as many of these applications require from the node to be autonomous and thus energy efficient. The topic of energy efficiency for the WSN is rich and many teams are proposing as many solutions as there are applications. One of the most promising solutions is the integration of adaptive blocks in the node, which can adapt their performances and thus their energy expenditure according to the application, environment or the energy budget. This would allow any type of WSNN to operate at an optimum energy point and achieve the highest energy efficiency possible. However, this solution has its own issues. The work presented in this thesis deals with the control of these adaptive blocks.The aim of this work is to efficiently transfer the control data and the sense&react data throughout the node to and from the corresponding adaptive blocks. The nature of WSNN itself imposes the use of a communication network capable of a fast and independent wake and sleep mode, while the nature of the data dictate the need for a complementary communication network, as the data can be either analog or digital, and as such, a typical network is not capable of handling it without the help of secondary conversion blocks.In this manuscript, a first asynchronous communication network is proposed to deal with the issue at hand, mainly the transfer of configuration data throughout a network, in an event-driven fashion, hence the use of the QDI asynchronous logic. This network is digital only and two versions were designed, a serial and a hybrid one, and the serial version was implemented in silicon. Both proved to be energy efficient, as the serial network only needs 1pJ/bit, while the hybrid one consumes 0,07pJ/bit at 0.6V in a 28nm FDSOI technology.In the second part of this work, an improvement targeting simpler and mixed-signals circuits was carried out, including the design and analysis of a network capable of efficiently transferring analog data.

The diploma thesis deals with the problem of social networking in banking sector of the Czech Republic. The goal of the thesis is to define a set of best practices for successful activity of banks on social networks, based on own research of current activity of selected Czech banks in social networks environment. The thesis is divided into four main chapters. The first chapter summarizes the findings of previous theses, which dealt with similar topic. The second chapter deals with the problem of social networking theoretically, describes the actual most important social networks in the world, suggests their division according to typical attributes and describes the most important ways of social networking usage for business. The third chapter contains own research of social networks usage by Czech banks, definition of criteria for evaluation of the research and the evaluation itself. The final chapter contains the set of best practices based on the research, which can be used for successful activity of banks in social networks environment. Keywords

Previous research has been conducted to try to explain the relationship between stress and focus for the use of different platforms for work communication. On the other hand, during a pandemic there is a lot that separates everyday life from how it was before the pandemic began and working from home was not as obvious as it is today. Applications whose number of daily users has skyrocketed can also account for a perceived stress for a user - how does this affect individuals’ ability to focus on the application? A survey was created and published for two weeks using previous research that examined the links be- tween stress and focus on social media. The study was conducted by collecting data from various forums related to relevant applications, where it is discovered that stress has a weak but significant effect on distractions outside applications and on distractions within applications. The results show that a perceived distraction outside the application can for 22% be explained by stress and within the application can for 16.6% be explained by stress. Results and the similarities between social media and platforms for work commu- nication are compared and discussed based on the presented theory and related research. / Tidigare forskning har utförts för att försöka förklara sambandet mellan stress och fokus för användandet av olika plattformar för arbetskommunikation. Däremot är det under en pandemi mycket som skiljer vardagen åt från hur det var innan pandemin började och hemmaarbete inte var en sådan självklarhet som det är i dagens läge. Applikationer som vars antal dagliga användare skjutit i höjden kan också stå för en upplevd stress för en användare- hur påverkar detta en individs förmåga att fokusera på applikationen? En enkät utformas och publicerades under två veckor med hjälp av tidigare forskning som undersökt kopplingen mellan stress och fokus för sociala medier. Undersökningen bedrivs genom att data samlas in från varierande forum tillhörande olika relevanta applikationer, där det kommer fram att stress har en svag, men signifikant påverkan på distraktioner utanför applikationen och på distraktioner inom applikationen. Resultaten visar att en upplevd distraktion utanför applikationen kan 22% förklaras av stress och inom applikationen kan 16.6% förklaras av stress. Resultaten och likheterna mellan sociala medier och plattformar för arbetskommunikation jämförs och diskuteras utifrån den presenterade teorin och relaterad forskning.

我們從自然語言領域中借用Thesaurus模型作為字彙關聯的基礎，陸續加入Folksonomy概念、Social Network Service指標的蒐集以及domain-specific ontology來建構Tag-Thesaurus模型，用來解決使用一般tagging system資源彙整能力不足的問題。首先我們對將要實驗的領域選取初始字彙，並利用這些字彙建構Tag-Thesaurus模型。接著將預先準備的這些字彙釋放到社會網路服務平台的tagging system中，透過社會網路服務平台中的tagging system來蒐集使用者對於資源的平面分類資訊，利用這些資訊來對Tag-Thesaurus模型持續地擴充。透過這樣的Tag-Thesaurus模型，我們將可以獲得較佳的資源彙整。domain-specific ontology的加入將可以強化由上而下的資源彙整。而Social Network Service當中的其他資訊，如FOAF[16]或是個人的偏好等，將可以提昇個人化資源彙整的能力。這樣的結合方式不僅是ontology應用的示範，我們更希望透過這樣的混合式模型，使得Web 2.0這樣子廣泛蒐集眾人智慧的概念能夠成為跨入語意網的橋樑。 / We aggregate various resources through the Tag-Thesaurus Model. There are three parts in Tag-Thesaurus model, the Folksonomy formal model, indices collection on Social Network Service, and lightweight domain-specific ontology. The Folksnomy model reconstruct relationships between tags, and we can aggregate resources by tags. The indices collection on Social Network Service help us to decide which resource are more important. Finally, the lightweight domain-specific ontology provide the standard interface to describe the relationships between tags.

在當時大家認為產品品質與顧客滿意呈現一維的線性關係時，狩也紀昭首先將二因子的概念應用在產品品質上，發現了品質也有二維的特性，因此可以辨別出何種品質較其他品質重要，藉以形成品質改善的優先順序，其後亦有學者將服務品質概念應用在Kano模式上，發現服務品質也有二維品質的特性，然而Kano模式僅能提供品質的屬性分類，卻無法瞭解目前使用者的狀態，因此後來有學者加入IPA( Importance-Performance Analysis )，藉以瞭解目前使用者主觀的感受如何，因此Kano模式是將品質作「定性」，也就是瞭解品質的特性，而IPA是將品質「定量」，也就是瞭解目前使用者的感受。然而將Kano模式與IPA結合後所提出之品質改善建議往往流於模式上的字面解釋，有些甚至不符合公司當時實際在管理品質的情境，因此本研究試著導入核心策略與戰略行動的概念，試著重新提出Kano模式與IPA結合後的品質改善建議。 接著本研究以E-S-QUAL網路服務品質為基礎，結合Kano模式與IPA分析方式，並以Facebook為研究對象，探討Facebook網路服務品質的特性是否具有二維品質模式，並以不同人口統計變項將樣本分群，探討不同人口統計變項下，使用者是否對Facebook網路服務品質特性之分類有所不同，最後驗證本研究所提出的品質改善建議之合理性，並同時與Kano模式與IPA結合的品質改善建議作一對比。 結果發現，Facebook的網路服務品質的確有二維品質的屬性，但在32項品質項目中，沒有任何一項為魅力品質，代表E-S-QUAL所提出的所有品質項目，對於Facebook的使用者而言，沒有一項品質會令他們愛慕或嚮往。而對於不同人口統計變項的使用者而言，對於Facebook的網路服務品質特性之分類，在某些構面上的確有所不同。最後利用分析過後的資料，實證本研究所提出之品質改善建議，同時比較Kano模式與IPA結合的品質改善建議，發現後者確實在某些品質改善建議上有所遺漏，並於本研究所提出之改善建議中加以彌補，以形成更為周全的品質改善建議。 / At the time we think that product quality and customer satisfaction is a linear relationship, hunting Zhao Ji first applied the concept of two factors theory on quality and found that quality and customer satisfaction also has two-dimensional relationship. So you can identify what kinds of quality are more important than others to the formation of quality improvement priorities. Other researches also applied the concept of the Kano model on service quality and found that service quality also has the two-dimensional quality attribute. However, Kano model only can provide the classification of quality attribute, but cannot understand the current experience of the user. So some researches subsequently joined the IPA( Importance-Performance Analysis ), in order to understand current user subjective experience. We can know Kano model is used to “qualitative”, that is, to understand the attributes of quality, while the IPA is used to “quantitative”, that is, to understand the users current experience. However, the quality improvement suggestions from the combination with Kano model and IPA tend to fellow the literal interpretation from two models. Some suggestions even mismatch the actual company management situation. Therefore, the core of this study tried to import the concept of strategy and strategic action into the combination of Kano model and IPA to submit new recommendations of quality improvement. Then this study, based on E-S-QUAL, combining with analysis methods of Kano model and IPA, and using Facebook as an example, explores whether the characteristics of Facebook social network service qualities show two-dimensional quality attributes. Grouping the samples by different demographic variables to explore whether different users will affect the classification of quality attributes. Finally, this study examines the reasonableness of quality improvement suggestions from itself and also makes a comparison with the suggestion combining with Kano model and IPA. The results showed that, Facebook’s network service qualities do have the two dimensional quality attributes. But in 32 network service quality items, there do not have any attractive quality attribute. It shows that, there is no one service quality item proposed from E-S-QUAL will be loved or desired by Facebook users. For the different demographic variable users, there are some different in classifying Facebook’s network service quality attributes in some dimension. Finally, this study uses the result from the data analyzed through Kano model and IPA to examine the reasonableness of quality improvement suggestions from itself, and also makes a comparison with the suggestion combining with Kano model and IPA. The examination discovered that the latter is indeed miss the quality improvement suggestion in some situation. So the suggestions of this study compensated the missing part and also proposed a more comprehensive suggestion for Facebook’s quality improvement.