Consumers are becoming increasingly concerned about their foods and more particularly, the origin of their foods and the ingredients they contain. In light of the demand for additional origin information, the 100% Canadian milk branding initiative was launched in 2009 as a means of informing consumers about the origin of milk in their dairy products. The information is indicated by the presence of the 100% Canadian milk symbol on dairy products and can be characterized a form of co-branding. The literature on co-branding stipulates that co-branding can result in changed product perceptions either negatively or positively. In addition, the willingness to pay (WTP) literature stipulates that WTP is determined by product attributes and individuals’ characteristics. This thesis therefore seeks to ascertain the factors affecting consumers’ preferences and WTP for products with the 100% Canadian milk symbol. Specifically, the effects of individual characteristics such as health consciousness, patriotic values and risk perceptions on preferences for dairy products with the symbol are evaluated. Concurrently, the study explores the relationship between respondents’ knowledge of the Canadian dairy industry and WTP for the symbol. Data were gathered from a total of 1012 milk and ice cream consumers using two nationwide internet surveys. Estimations are carried out using the Multinomial Logit (MNL) and the Random Parameter Logit models (RPL). The results suggest that consumers in general have positive perceptions of milk and ice cream with the 100% Canadian milk symbol but negatively perceive store brand and organic labels. However, in some cases, combining a store brand label or organic label with the 100% Canadian milk symbol, are shown to alter consumers’ perceptions of the product. Some socio-demographic variables and individual characteristics were also found to be influential in intended purchase behaviours and WTP for milk and ice cream. The findings from this study provide information on consumers’ perceptions and attribute preferences and are expected therefore to contribute to the marketing strategies of the Canadian dairy industry as a whole.

The future Internet will be an IPv6 network interconnecting traditional computers and a large number of smart object or networks such as Wireless Sensor Networks (WSNs). This Internet of Things (IoT) will be the foundation of many services and our daily life will depend on its availability and reliable operations. Therefore, among many other issues, the challenge of implementing secure communication in the IoT must be addressed. The traditional Internet has established and tested ways of securing networks. The IoT is a hybrid network of the Internet and resource-constrained networks, and it is therefore reasonable to explore the options of using security mechanisms standardized for the Internet in the IoT. The IoT requires multi-facet security solutions where the communication is secured with confidentiality, integrity, and authentication services; the network is protected against intrusions and disruptions; and the data inside a sensor node is stored in an encrypted form. Using standardized mechanisms, communication in the IoT can be secured at different layers: at the link layer with IEEE 802.15.4 security, at the network layer with IP security (IPsec), and at the transport layer with Datagram Transport Layer Security (DTLS). Even when the IoT is secured with encryption and authentication, sensor nodes are exposed to wireless attacks both from inside the WSN and from the Internet. Hence an Intrusion Detection System (IDS) and firewalls are needed. Since the nodes inside WSNs can be captured and cloned, protection of stored data is also important. This thesis has three main contributions. (i) It enables secure communication in the IoT using lightweight compressed yet standard compliant IPsec, DTLS, and IEEE 802.15.4 link layer security; and it discusses the pros and cons of each of these solutions. The proposed security solutions are implemented and evaluated in an IoT setup on real hardware. (ii) This thesis also presents the design, implementation, and evaluation of a novel IDS for the IoT. (iii) Last but not least, it also provides mechanisms to protect data inside constrained nodes. The experimental evaluation of the different solutions shows that the resource-constrained devices in the IoT can be secured with IPsec, DTLS, and 802.15.4 security; can be efficiently protected against intrusions; and the proposed combined secure storage and communication mechanisms can significantly reduce the security-related operations and energy consumption.

Orientador: Prof. Dr. João Henrique Kleinschmidt / Dissertação (mestrado) - Universidade Federal do ABC, Programa de Pós-Graduação em Engenharia da Informação, 2017. / O interesse pela Internet das Coisas cresceu nos últimos anos e alavancou o estudo das tecnologias necessárias para o perfeito funcionamento desse novo paradigma. As mais diversas áreas do conhecimento tem influência sobre a IoT, desde as áreas ligadas a engenharia, preocupadas com a criação de padrões, dispositivos e aplicações, à áreas ligadas a legislação, comunicação, marketing, etc. Dentro do estudo da engenharia, o campo das padronizações tem trazido muitas oportunidades. A demanda por desenvolvimento de padrões que possibilitem a interoperabilidade de dispositivos aumenta a cada ano. Organizações, como IETF, já disponibilizaram uma série de protocolos dedicados à IoT, dentre eles o protocolo de roteamento RPL, que foi desenvolvido para redes de baixa potência com perdas. O trabalho apresentado a seguir faz o estudo do protocolo RPL em cenários híbridos, ou seja, onde os nós são móveis ou estáticos. Esse trabalho é necessário pois grande parte das aplicações de IoT serão utilizadas por dispositivos móveis e a especificação do RPL não contempla a mobilidade dos nós. O objetivo deste trabalho é entender como o protocolo se comporta nestes cenários cenários híbridos. A mobilidade dos nós é definida por modelos de mobilidade consagrados, como o Manhattan e o Random Waypoint. Notou-se que a mobilidade dos nós elevou a perda de pacotes da rede bem como o atraso. Além disso foi possível verificar com base no ETX que houve alteração da topologia da rede. Essas mudanças causada pela presença de nós móveis ocasionaram a elevação do consumo de energia dos nós. Verificou-se também que o ciclo de trabalho dos nós tem influência direta no desempenho do protocolo. / The interest in the Internet of Things has grown in recent years and has leveraged the study of the technologies necessary for the functioning of this new paradigm. The most different areas of knowledge have an influence on the IoT, since areas related to engineering, concerned about standards, development, devices and applications, until areas related to legislation, ncommunication, marketing, etc. In the engineering study, the standardization area has brought many opportunities. The demand for standards development that enables device interoperability increases every year. Organizations such as IETF already provided a series of protocols dedicated to IoT, including the RPL routing protocol, which was developed for lowpower lossy networks. The work presented here makes a study of the RPL protocol in hybrid scenarios, in other words, where the nodes are mobile or static. This work is necessary because most of the IoT applications will be used by mobile devices and the RPL specification does not include nodes mobility. The objective of this work is to understand the behavior of the protocol in hybrid scenarios. Nodes mobility is defined by well know mobility models, such as Manhattan and Random Waypoint. In this work was possible to verify the increase of latency and packet loss because of the nodes mobility. In addition, it was possible to verify, based on the ETX, that there was a change in the network topology. These changes caused by mobile nodes increase the power consumption. It was also verified that the duty cycle of the nodes has a direct influence in the protocol performance.

Thesis (Ph. D. (Language Education)) -- University of Limpopo, 2016 / This study investigates the challenges for an implementation of Recognition of Prior Learning (RPL) at three FET Colleges in Limpopo Province. The implementation of RPL in the South African education system is seen as an essential tool to drive transformation in FET Colleges. RPL was designed to play a unique role in the provision of the higher level skills required to support the socio-economic growth and development of the nation. With all these good intentions, RPL is virtually non-existent in our public FET Colleges. This is a qualitative case study in which both exploratory and descriptive designs were used. Data was collected from observations, documents, interviews and questionnaires from the learners and educators. Twenty one learners and seven educators were interviewed. Questionnaires were distributed to nine educators. The purposive sampling method was used. The significant findings are that there are no RPL policy guidelines, no quality management systems, a shortage of accredited staff and equipment prescribed for RPL, and lack of management and leadership commitment to implementation of RPL. This study therefore recommends the urgent implementation of RPL in FET colleges to promote access and to urgently address the needed skills for the nation. The research also recommends an effective model on quality assurance which appears to be compromised in colleges. The research also recommends effective and efficient training of educators, as this study revealed that the educators have low academic qualifications. While the Ministerial Task Team on RPL recommends a holistic approach to implementation, this research recommends an effective training model for the FET educators to implement RPL.

Les réseaux de capteurs sans fil (RCSF) sont très largement utilisés dans divers domaines d'applications civiles et militaires, comme la surveillance de champs de bataille, la détection de phénomène environnementaux, ou encore les bâtiments intelligents. Cependant, les réseaux de capteurs sans fil sont caractérisés par de fortes limitations au niveau de l'énergie disponible et des communications radio. Les travaux réalisés dans cette thèse visent à proposer des solutions garantissant une certaine qualité de service dans le contexte des réseaux de capteurs sans fil. La première partie concerne la couche liaison de données avec l'objectif d'augmenter la durée de vie du réseau. L'accès au médium sans fil est analysé et modélisé sous la forme d'un problème d'ordonnancement des liens de communication, tenant compte des collisions. Nous étudions alors la complexité de ce problème. Une approche distribuée et tolérante aux défaillances avec garantie de performance est proposée (SS-DD2EC) pour résoudre ce problème. La seconde partie de la thèse concerne le routage des messages à l'aide du protocle IPv6 Routing Protocol for Low-Power and Lossy Network (RPL). Tout d'abord, un comparatif entre les différentes métriques de routage existantes pour l'optimisation de l'énergie consommée a été mené. En plus de la durée de vie, les critères de fiabilité et de latence de bout-en-bout sont considérés pour évaluer ces métriques. Enfin, deux nouvelles métriques (R_MinMax et R_Delai) ont été proposées pour RPL permettant d'atteindre des gains significatifs par rapport à l'état de l'art. La première ne tient compte que des critères de consommation d'énergie et de fiabilité, alors que la seconde intègre en plus la latence de bout-en-bout. / Wireless sensor networks (RCSF) is a technology that has a wide range of civil or military applications, including battlefield monitoring, environmental monitoring or smart city. However, WSN are characterized by high limitations in terms of energy (battery-operated nodes) and wireless links (low power and lossy links). The work done in this PhD thesis aims to provide solutions that guarantee a certain quality of service in the context of wireless sensor networks. The first part of this work concerns the medium access control layer with the aim of increasing the lifetime of the network. The access to the wireless medium is analyzed and modeled as a link scheduling problem, taking into account collisions. First, a study of the complexity of this problem is carried out, then a distributed and fault-tolerant approach with guaranteed performance is proposed (SS-DD2EC) to solve this problem. The second part is about message routing with the IPv6 Routing Protocol for Low Power and Lossy Network (RPL). First of all, a comparison between the various existing routing metrics for the optimization of the energy consumed has been carried out. In addition of lifetime, the reliability and end-to-end latency criteria are considered for evaluating these metrics. Then, two new RPL metrics (R_MinMax and R_Delai) were proposed, achieving significant gains over the state of the art. The first one only considers the energy consumption and reliability, while the second one takes also into account the end-to-end latency.

The size of the IoT network is expanding due to advancements in the IoT field, leading to increased interest in the multi-sink mechanism. The IPv6 Routing Protocol for Low-Power and Lossy Networks (RPL) is a representative IoT protocol that focuses on the Low-Power and Lossy Networks. However, research on comparing multi-sink strategies within the RPL network is limited. Therefore, this project aims to compare three common strategies: multiple-DODAG in one instance, virtual root, and multiple-instance. Using these strategies, we design and implement RPL networks and conduct simulations in various scenarios. Five different topologies are utilized in the experiments, considering different packet loss rates. Performance evaluation of each strategy is conducted using the Cooja simulator and Contiki-NG system, with a focus on the number of RPL control packets, Packet Delivery Ratio (PDR), and energy consumption. The results indicate that both the virtual root and multiple-DODAG strategies perform well with low packet loss, while the virtual root strategy outperforms the multiple-DODAG strategy with high packet loss. Additionally, the virtual root strategy incurs slightly higher energy costs than the multiple-DODAG strategy. Furthermore, the multiple-instance strategy demonstrates poor performance in most scenarios, except for the packet delivery ratio under high packet loss conditions. Besides the analysis, potential areas for future research on the RPL’s multi-sink mechanism are finally identified. / Storleken på IoT-nätverket expanderar på grund av framsteg inom IoT-området, vilket leder till ökat intresse för multi-sink-mekanismen. IPv6 Routing Protocol for Low-Power and Lossy Networks (RPL) är ett representativt IoT-protokoll som fokuserar på Nät med låg effekt och förluster. Forskningen om jämförelse av multi-sink-strategier inom RPL-nätverket är dock begränsad. Därför syftar detta projekt till att jämföra tre vanliga strategier: multiple - DODAG i en instans, virtuell rot och multi-instans. Med hjälp av dessa strategier designar och implementerar vi RPL-nätverk och genomför simuleringar i olika scenarier. Fem olika topologier används i experimenten, med olika packet loss rate. Prestationsutvärdering av varje strategi utförs med hjälp av Cooja-simulatorn och Contiki-NG-systemet, med fokus på antalet RPL control packets, Packet Delivery Ratio (PDR) och energiförbrukning. Resultaten indikerar att både virtuell rot och multiple-DODAG strategier fungerar bra vid låg datapaketförlust, medan den virtuella rotstrategin överträffar multiple-DODAG strategin vid hög datapaketförlust. Dessutom medför den virtuella rotstrategin något högre energikostnader än flera DODAG-strategin. Dessutom visar multi-instans-strategin dålig prestanda i de flesta scenarier, förutom när det gäller datapaketleveransförhållandet under höga datapaketförlustförhållanden. Utöver analysen identifieras slutligen potentiella områden för framtida forskning om RPL-protokollets multi-sink-mekanism.

Recognition of prior learning, better known as RPL, was introduced to training institutions in South Africa after the fall of Apartheid. The objective of RPL was to redress inequalities brought about by Apartheid when disadvantaged groups had less access to training opportunities. RPL was introduced with a combination of associated training and education initiatives such as the National Qualification Framework and the South African Qualifications Authority, all directed for a similar purpose. The South African Nursing Council agreed with the principles of RPL and published a policy document aimed to guide nurse educators to enhance RPL implementation in South African nursing education institutions. Despite the support from accessible legislative and regulatory documentation, RPL is implemented insufficiently in nursing education institutions. The lack of RPL implementation was also identified by the researcher in the Limpopo College of Nursing. This College of Nursing can be described as a symbol of post-Apartheid re-integration whereby nursing colleges centralised into one administrative management office with campuses, satellite campuses and over 120 nurse educators. The research question asked was what are nurse educators’ perceptions of the implementation of RPL in nursing colleges in Limpopo Province? The aim was to support nurse educators to enhance the implementation of RPL in nursing colleges in Limpopo Province. A qualitative, phenomenological, explorative, descriptive and contextual research design was followed. Seven (n=7) individual, in-depth, unstructured interviews were conducted with nurse educators employed at the X Campus and Y Satellite Campus of the Limpopo College of Nursing. Transcribed interviews were analysed and resulted in three main themes and nine sub-themes. Firstly, the participants voiced their agreement that RPL should be implemented and identified specific benefits and challenges thereof. Secondly, there should be a RPL assessment package that should be open and transparent, be able to assess academic performance against college standards and should minimise inequalities. The third main theme was the need for enhanced awareness of RPL implementation in nursing colleges. Nurse educators lack knowledge about RPL and should therefore be more awareness thereof. In addition RPL should be promoted as a beneficial mechanism to the learning process. These results were discussed with a literature integration and in the majority of results literature confirmed these findings. Conclusion statements were formulated from the research results and served as the basis for the formulation of recommendations to support nurse educators with the implementation of RPL in nursing colleges in Limpopo Province. The recommendations were directed to firstly the policy makers in nursing education; secondly to the nursing education institutions and thirdly to the nurse educators. Areas for further research were listed. Strategies to enhance trustworthiness and the adherence of ethical considerations were supported throughout this study. / MCur, North-West University, Potchefstroom Campus, 2014

Internet of Things (IoT) has been paving the way for a plethora of potential applications, which becomes more spatial and demanding. The goal of this work is to optimise the performance within the IPv6 Routing Protocol for Low-Power and Lossy Networks (RPL) in the network layer. RPL still suffers from unbalanced load traffic among the candidate parents. Consequently, the overloaded parent node drains its energy much faster than other candidate parent nodes. This may lead to an early disconnection of a part of the network topology and affect the overall network reliability. To solve this problem, a new objective function (OF) has been proposed to usher better load balancing among the bottleneck candidate parents, and keep the overloaded nodes lifetime thriving to longer survival. Moreover, several IoT applications have antagonistic requirements but pertinent, which results in a greater risk of affecting the network reliability, especially within the emergency scenarios. With the presence of this challenging issue, the current standardised RPL OFs cannot sufficiently fulfil the antagonistic needs of Low-power and Lossy Networks (LLNs) applications. In response to the above issues, a context adaptive OF has been proposed to facilitate exchanging the synergy information between the application and network layers. Thus, the impact of the antagonistic requirements based on context parameters will be mitigated via rationalizing the selection decision of the routing path towards the root node. We implemented the proposed protocol and verified all our findings through excessive measurements via simulations and a realistic deployment using a real testbed of a multi-hop LLNs motes. The results proved the superiority of our solution over the existing ones with respect to end-to-end delay, packet delivery ratio and network lifetime. Our contribution has been accepted initially to be adopted within the standard body Internet Engineering Task Force (IETF).

Recognition of prior learning, better known as RPL, was introduced to training institutions in South Africa after the fall of Apartheid. The objective of RPL was to redress inequalities brought about by Apartheid when disadvantaged groups had less access to training opportunities. RPL was introduced with a combination of associated training and education initiatives such as the National Qualification Framework and the South African Qualifications Authority, all directed for a similar purpose. The South African Nursing Council agreed with the principles of RPL and published a policy document aimed to guide nurse educators to enhance RPL implementation in South African nursing education institutions. Despite the support from accessible legislative and regulatory documentation, RPL is implemented insufficiently in nursing education institutions. The lack of RPL implementation was also identified by the researcher in the Limpopo College of Nursing. This College of Nursing can be described as a symbol of post-Apartheid re-integration whereby nursing colleges centralised into one administrative management office with campuses, satellite campuses and over 120 nurse educators. The research question asked was what are nurse educators’ perceptions of the implementation of RPL in nursing colleges in Limpopo Province? The aim was to support nurse educators to enhance the implementation of RPL in nursing colleges in Limpopo Province. A qualitative, phenomenological, explorative, descriptive and contextual research design was followed. Seven (n=7) individual, in-depth, unstructured interviews were conducted with nurse educators employed at the X Campus and Y Satellite Campus of the Limpopo College of Nursing. Transcribed interviews were analysed and resulted in three main themes and nine sub-themes. Firstly, the participants voiced their agreement that RPL should be implemented and identified specific benefits and challenges thereof. Secondly, there should be a RPL assessment package that should be open and transparent, be able to assess academic performance against college standards and should minimise inequalities. The third main theme was the need for enhanced awareness of RPL implementation in nursing colleges. Nurse educators lack knowledge about RPL and should therefore be more awareness thereof. In addition RPL should be promoted as a beneficial mechanism to the learning process. These results were discussed with a literature integration and in the majority of results literature confirmed these findings. Conclusion statements were formulated from the research results and served as the basis for the formulation of recommendations to support nurse educators with the implementation of RPL in nursing colleges in Limpopo Province. The recommendations were directed to firstly the policy makers in nursing education; secondly to the nursing education institutions and thirdly to the nurse educators. Areas for further research were listed. Strategies to enhance trustworthiness and the adherence of ethical considerations were supported throughout this study. / MCur, North-West University, Potchefstroom Campus, 2014

Submitted by Maykon Nascimento (maykon.albani@hotmail.com) on 2015-08-03T18:18:50Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Roteamento sensível ao contexto em redes de sensores sem fio. Uma abordagem baseada em regras de aplicação para o protocolo RPL.pdf: 1746170 bytes, checksum: 7293ea85d09a8c011b6f38ae51b024de (MD5) / Approved for entry into archive by Elizabete Silva (elizabete.silva@ufes.br) on 2015-08-17T19:10:23Z (GMT) No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Roteamento sensível ao contexto em redes de sensores sem fio. Uma abordagem baseada em regras de aplicação para o protocolo RPL.pdf: 1746170 bytes, checksum: 7293ea85d09a8c011b6f38ae51b024de (MD5) / Made available in DSpace on 2015-08-17T19:10:23Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Roteamento sensível ao contexto em redes de sensores sem fio. Uma abordagem baseada em regras de aplicação para o protocolo RPL.pdf: 1746170 bytes, checksum: 7293ea85d09a8c011b6f38ae51b024de (MD5) Previous issue date: 2015 / Este trabalho apresenta um serviço de reconfiguração dinâmica para Redes de Sensores sem Fio. O trabalho inclui o projeto e a definição de uma arquitetura conceitual que suporta a coleta de uma variedade de informações contextuais e provê uma abstração alto nível para especificação de roteamento sensível ao contexto através de reconfiguração de métricas de roteamento e parâmetros de comunicação. O objetivo da infraestrutura proposta é possibilitar a criação de regras que adaptem o comportamento da rede em tempo de execução, em função dessas informações contextuais. Uma implementação da arquitetura para o protocolo RPL e o sistema operacional Contiki foi realizada, mostrando a viabilidade da abordagem proposta. / This work presents a dynamic reconfiguration service for wireless sensor networks. The work includes the design and definition of a conceptual architecture that supports collecting a variety of contextual information and provides a high level abstraction for context-sensitive routing specification through reconfiguration of routing metrics and communication parameters. The objective of the proposed infrastructure is enabling the creation of rules that change the network's behavior at run time, in the light of these contextual information. An implementation of the architecture for the RPL Protocol and the Contiki operating system was performed, showing the feasibility of the proposed approach.