Radiofrequency spectrum is a finite resource that consists of the frequencies in the range 3 kHz to 300 GHz. It is used for wireless communication and supports several applications and services. Whether it is at the personal, community or society level, and whether it is for applications in consumer electronics, building management, smart utility networks, intelligent driving systems, the Internet of Things, industrial automation and so on, the demand for wireless communication is increasing continuously. Together with this increase in demand, there is an increase in the quality of service requirements in terms of throughput, and the reliability and availability of wireless services. Industrial wireless sensor networks, for example, operate in environments that are usually harsh and time varying. The frequency spectrum that is utilised by industrial wireless protocols such as WirelessHART and ISA 100.11a, is also used by many other wireless technologies, and with wireless applications growing rapidly, it is possible that multiple heterogeneous wireless systems will need to operate in overlapping spatiotemporal regions in the future. Increased radiofrequency interference affects connectivity and reduces communication link quality. This affects reliability and latency negatively, both of which are core quality service requirements. Getting multiple heterogeneous radio systems to co-exist harmoniously in shared spectrum is challenging. Traditionally, this has been achieved by granting network operators exclusive rights that allow them to access parts of the spectrum assigned to them and hence the problems of co-existence and limited spectrum could be ignored. Design time multi-access techniques have also been used. At present, however, it has become necessary to use spectrum more efficiently, to facilitate the further growth of wireless communication. This can be achieved in a number of ways. Firstly, the policy that governs the regulation of radiofrequency spectrum must be updated to accommodate flexible, dynamic spectrum access. Secondly, new techniques for multiple-access and spectrum sharing should be devised. A revolutionary new communication paradigm is required, and one such paradigm has recently emerged in the form of Cognitive Radio technology. Traditional methods to sharing spectrum assume that radios in a wireless network work together in an unchanging environment. Cognitive radios, on the other hand, can sense, learn and adapt. In cognitive radio networks, the interactions between users are taken into account, in order for adjustments to be made to suit the prevailing radio environment. In this thesis, the problem of spectrum scarcity and coexistence is addressed using cognitive radio techniques, to ensure more efficient use of radio-frequency spectrum. An introduction to cognitive radio networks is given, covering cognitive radio fundamentals, spectrum sensing, dynamic spectrum management, game theoretic approaches to spectrum sharing and security in cognitive radio networks. A focus is placed on wireless industrial networks as a challenging test case for cognitive radio. A study on spectrum management policy is conducted, together with an investigation into the current state of radio-frequency spectrum utilisation, to uncover real and artificial cases of spectrum scarcity. A novel cognitive radio protocol is developed together with an open source test bed for it. Finally, a game theoretic dynamic spectrum access algorithm is developed that can provide scalable, fast convergence spectrum sharing in cognitive radio networks. This work is a humble contribution to the advancement of wireless communication. / Thesis (PhD)--University of Pretoria, 2016. / Centre for Telecommunication Engineering for the Information Society / Electrical, Electronic and Computer Engineering / PhD / Unrestricted

The evolution of the internet of things (IoT) opens the market opportunity for organic photovoltaic cells, especially for indoor applications where the lifetime of the organic cells is longer than outdoor. For example, IoT requires off-grid energy sources for many devices with low power consumption. In this work, new materials were tested as candidate components in the active layer of printed organic photovoltaics by fabrication of devices. The initial electrical performance of these devices and their stability over time were investigated by measurements of the current-voltage characteristics. Three selected active layers were further investigated with atomic force microscopy (AFM) measurements. The current-voltage measurements showed that the addition of a solvent additive to the active layer ink affects the initial electrical performance as well as the stability of the devices. The AFM measurements showed that the surface topography of the active layer was affected by the sort of solvent additive that was used. Three new electron acceptor material and two solvent additives showed promising electrical performance and stability.

A l’ère de la troisième révolution internet, celle de l’internet des objets (IoT), beaucoup d’espoir sont tournés vers les technologies numériques pour développer les économies et notamment dynamiser le commerce local. Dans les pays du Maghreb, en Tunisie notamment, ses espoirs sont tournés du côté de la demande. Plus précisément, à l’issu du printemps arabe, et en raison du rôle qu’ont joué les réseaux sociaux (Facebook notamment) pour mobiliser les jeunes à manifester dans les rues de Tunis, le nouveau ministère du commerce fonde ses espoirs dans cette population jeune pour développer le commerce électronique. Partant de ce constat, cette thèse propose d’étudier si les jeunes tunisiens sont les early adopters qui permettront de diffuser le commerce électronique en Tunisie. Pour cela, la problématique de recherche porte sur les facteurs d’adoption du commerce électronique par les jeunes en Tunisie. Pour répondre à cette question de recherche, la thèse propose dans un premier temps de dresser l’état des lieux de la diffusion de l’internet au sein d’un population de jeunes étudiants. Préalablement, elle propose dans la première partie de la thèse un état des lieux de la couverture du territoire en technologies d’accès aux services numériques. Cet état des lieux est discuté à l’appui d’une revue de la littérature sur la fracture numérique. Dans un deuxième temps, elle propose une analyse empirique et exploratoire menée auprès d’un échantillon de 400 étudiants tunisiens environ. Cette étude porte sur les facteurs d’adoption de l’internet et des services marchands (commerce électronique). Structurée en deux parties, le premier volet de l’enquête est exploité à l’aide de statistiques économétriques et le deuxième volet mobilise les méthodes d’analyse d’équations structurelles. Les résultats de la thèse montrent que si l’usage de l’internet est relativement bien diffusé auprès des jeunes tunisiens, la disposition à adopter le commerce électronique doit en revanche être encouragée. Pour cela, un modèle d’adoption est proposé en deuxième partie de la thèse. Il met en évidence quels facteurs favorisent ou inhibent l’adoption du commerce électronique en Tunisie. Les résultats de ce modèle et des travaux menés dans la partie 1 permettent dans la partie conclusive de la thèse de formuler différentes recommandations à l’égard des entreprises engagées dans un projet de mise en ligne de leur activité commerciale d’une part, et d’autre part envers les acteurs publics pour favoriser l’adoption des services internet marchands en Tunisie. / In the era of the third Internet revolution, that of the Internet of Things (IoT), a lot of hope is turned to digital technologies to develop economies and boost local trade. In the Maghreb countries, especially in Tunisia, those hope are turned on the demand side. More specifically, at the end of the Arab Spring, and because of the role played by social networks (Facebook in particular) to mobilize young people to demonstrate in the streets of Tunis, the new Ministry of Commerce hopes in this population young to develop e-commerce. Based on this observation, this thesis proposes to study whether young Tunisians are the early adopters who will disseminate e-commerce in Tunisia. For this, the research problematic focuses on the factors of adoption of e-commerce by young people in Tunisia. To answer this research question, the thesis proposes at first to draw up the inventory of the diffusion of the internet within a population of young students. Before doing so, we propose in the first part of the thesis an inventory of the technologies territory’s coverage of the access to digital services. This inventory is discussed in support of a review of the literature on the digital divide. In a second step, she proposes an empirical and exploratory analysis conducted with a sample of about 400 Tunisian students. This study focuses on the adoption factors of the Internet and market services (e-commerce). Structured in two parts, the first part of the survey is exploited using econometric statistics and the second part uses structural equation analysis methods. The results of the thesis show that while the use of the internet is relatively well distributed to young Tunisians, the willingness to adopt e-commerce should be encouraged. For this, an adoption model is proposed in the second part of the thesis. It highlights what factors encourages or inhibit the adoption of e-commerce in Tunisia. The results of this model and the work carried out in Part 1 allow in the concluding part of the thesis to make various recommendations to companies engaged in a project to put their commercial activity online on one hand, and on the other hand towards the public actors to encourage the adoption of the internet marketing services in Tunisia.

Philosophiae Doctor - PhD / Cloud Computing enables users achieve ubiquitous on-demand , and convenient access to a variety of shared computing resources, such as serves network, storage ,applications and more. As a business model, Cloud Computing has been openly welcomed by users and has become one of the research hotspots in the field of information and communication technology. This is because it provides users with on-demand customization and pay-per-use resource acquisition methods.

The Internet of Things (IoT) has evolved to be an important part of modern society. IoT devices can be found in several environments such as smart homes, transportation, the health sector, smart cities and even facilitates automation in organisations. The increasing dependence on IoT devices increases the possibility of security incidents in the physical or cyber environment. Traditional methods of digital forensic (DF) investigations are not always applicable to IoT devices due to their limited data processing resources. A possible solution for conducting forensic investigations on IoT devices is to utilise a proactive approach known as digital forensic readiness (DFR). This dissertation firstly aims to conduct a thorough review of the available literature in the current body of knowledge to identify a clear process that can be followed to implement DFR tailored for IoT devices. This dissertation then formulates requirements for DFR in IoT based on existing forensic techniques. The requirements for DFR in IoT give rise to the development of a model for DFR in IoT, which is then implemented in a prototype for IoT devices. The prototype is subsequently tested and evaluated on IoT devices that conduct proactive DFR in a simulation of a smart home system. Finally, the dissertation illustrates the feasibility of the DFR processes for IoT and serves as a basis for future research with regards to DFR in IoT. This dissertation will impact future research with regards to developing a standard for DFR in IoT. / Dissertation (MSc)--University of Pretoria, 2019. / Computer Science / MSc / Unrestricted

The purpose of this thesis is to describe and implement how a specific form of IoT, sensors, can be integrated with BIM in order to improve the building performance, when the perspective taken is the end-users. It seeks to explore different perceived values of BIM and sensor integration for the occupants who directly use the building facilities. The thesis also describes the concept, frameworks and cases of how BIM and sensors integration can be setup. These are used for an implementation at a case facility. Three main methods are used – literature review, comparative case study, and a smallscale implementation, containing a survey and sensor implementation based on the respondents’ satisfaction with the office air quality. A basic literature review is used to gather the fundamental concepts used within the relevant areas, and to review the empirical research connected to these. The conceptual part of the thesis review frameworks for BIM and sensor integration, and points toward a more user-centric framework that is later developed in relation to the thesis’ empirical results. The theoretical framework integrates Information Systems Theories with Knowledge Management for a framework of understanding how knowledge about new kinds of Information Systems in developing areas function. The empirical part of the thesis is structured into two main phases, one descriptive comparative case study, and the other an implementation based in the first phase results. The first phase is descriptive, where two cases of sensor and BIM implementation processes for FM are described. The main case of Tyréns company (Tyréns), and a reference case of Mästerhuset is used for understanding how different organizational structures may lead to different perceived values and processes of BIM and sensor integration for the end-users. The second phase is an implementation at the main case, Tyréns’ headquarter building. Here the end-user perspective is employed with a survey that is constructed in accordance with some of the fundamental concepts and research reviewed, in order to measure the perceived satisfaction with the air quality of the end-users working environment. The answers show concerns with air quality in the meeting rooms, and this is used as the basis for a small-scale implementation of sensors, where CO2 and temperature sensors are set up. The results show how different organizational-specific conditions generate different perceived values of BIM and sensor integration depending on ownership relation to the end-users. The case study also illustrate the different processes of BIM and sensor integration may be setup to supplement building performance. This points to a needed add-on into frameworks that conceptualizes BIM and sensor integration without the inclusion of the end-users’ perspective. Based on this an end-user conceptual framework of BIM and sensors is proposed with the supplementary part of a knowledge layer, named analytic layer and data source from occupants.

<div> <div> <div> <p>This thesis aims to introduce a system design that supports the user experience of outfit selection, storage, and matching. Clothes are indispensable items in daily human life. Purchasing one's wardrobe has become more affordable. This has allowed people to focus on purchasing more fashionable clothes. Garment shopping has even become a type of social and leisure activity. With the development of internet technology, shopping methods have changed dramatically. However, these seemingly convenient shopping methods also bring unavoidable problems, such as an inability to understand apparel companies' different size standards and the challenge of seeing the details of materials. On the other side, while overemphasizing the convenience of the shopping process, online companies have ignored people's clothes-wearing experience that is the most enjoyable and valuable for customers. This paper introduces an IoT (Internet of Things) design: "Closet Go" including a mobile application and a clip-able camera. "Closet Go" aims to improve customers' daily outfit selection experience by digitalizing their closets and conducting data analysis of customized dressing habits. In this thesis, I present the entire design process: user research, Ideation, UI/UX design, product development, and evaluation. In the research section, potential users were recruited for interviews to discover the current problems in acquiring, selecting, and matching outfits in daily life. The design process section introduces the design development progress and results via user flow, experience map, prototype, and user interface. Finally, the thesis concludes with a heuristics evaluation section that tests the design's usability and experience to refine the project. </p> </div> </div> </div>

Telehealth is an online health care system that is extensively used in the current pandemic situation. Our proposed technique is considered a fog computing-based attack detection architecture to protect IoT Telehealth Networks. As for IoT Telehealth Networks, the sensor/actuator edge devices are considered the weakest link in the IoT system and are obvious targets of attacks such as botnet attacks. In this thesis, we introduce a novel framework that employs several machine learning and data analysis techniques to detect those attacks. We evaluate the effectiveness of the proposed framework using two publicly available datasets from real-world scenarios. These datasets contain a variety of attacks with different characteristics. The robustness of the proposed framework and its ability, to detect and distinguish between the existing IoT attacks that are tested by combining the two datasets for cross-evaluation. This combination is based on a novel technique for generating supplementary data instances, which employs GAN (generative adversarial networks) for data augmentation and to ensure that the number of samples and features are balanced. / Graduate

Vi befinner oss i en transformation där elcykeln tillför en ny dimension av mobilitet. Samtidigt sker ett teknologiskifte där Internet of Things (IoT) möjliggör uppkoppling av produkter till varandra och från produkt till människa, på ett sätt som tillför nya värden. Elcykeln är inget undantag. Med IoT blir elcykeln intelligent; den smarta elcykeln är här. Smarta elcyklar är nytt på den svenska marknaden. För att förstå hur affärsmodeller och betalningsmodeller kan skapas kring denna nya produkt undersöks inställning till, och drivkrafter för, den smarta elcykeln. Vidare prövas inställningen till olika betalningsmodeller.Resultaten visar att elcykelcyklisten är intresserad av att skaffa sig en smart elcykel och helst vill man betala hela beloppet direkt vid köpet, även om man är öppen för alternativa betalformer som bygger på cykeln som tjänst.I arbetet konstateras att det finns samband mellan teknikintresse och inställningen till smarta elcyklar liksom samband mellan inställning till olika betalningsmodeller och inställning till den smarta elcykeln.Arbetet utgör en grund för vidare forskning kring den smarta elcykeln och affärsmodeller baserade på elcyklar uppkopplade genom IoT.

The enterprise systems are built with a monolithic way of software architecture which may not be the very suitable and realistic solutions, due to the quantity and diversity of Internet of Things (IOT) devices connected to the internet. The large code is based as a single deployable unit; making it cumbersome and difficult to change, test, and deploy – typically in the monthly deployment cycles. Which could potentially be a large impact and high-risk for updates and deployment build up between releases.  The thesis aims to exploit Microservices Architecture in context of the Internet of Things. Because of scalability and rapid deployment, Microservices Architecture (MSA) naturally fits for M2M and IOT developments. Therefore, it has become increasingly popular and highly suited as a design choice in the context of developing IOT applications. We have proposed various ontologies for conceptual architecture designs. Our conceptual model encompasses all the essential elements and entities that constitute IOT; describing various characteristics of microservices and consideration to be used as a basis for developing a Reference Architecture model. The reference architecture is effectively exploiting Microservices Architectural Style for a diverse set of things composition like sensor devices, connectivity and transportation protocols for IP enabled IOT smart objects.  The thesis will contribute to the conceptual space of more successful reference architectures. The goal is to provide features and deployment information with instantiation guidelines to derive the software architecture instances in a given IOT application domain. Thus, it promises to become a valuable framework in the derivation of the Microservices IOT architectures.