Along with rapid development of sensing and communication technology, Internet of Things (IoTs) has enabled a tremendous number of applications in health care, agriculture, and industry. As the fundamental element, the wireless sensing node, such as radio tags need to be operating under micro power level for energy autonomy. The evolution of electronics towards highly energy-efficient systems requires joint efforts in developing innovative architectures and circuit techniques. In this dissertation, we explore ultra-low power circuits and systems for micropower wireless sensing in the context of IoTs, with a special focus on radio interfaces and sensor interfaces. The system architecture of UHF/UWB asymmetric radio is introduced firstly. The active UWB radio is employed for the tag-to-reader communication while the conventional UHF radio is used to power up and inventory the tag. On the tag side, an ultra-low power, high pulse swing, and power scalable UWB transmitter is studied. On the reader side, an asymmetric UHF/UWB reader is designed. Secondly, to eliminate power-hungry frequency synthesis circuitry, an energy-efficient UWB transmitter with wireless clock harvesting is presented. The transmitter is powered by an UHF signal wirelessly and respond UWB pulses by locking-gating-amplifying the sub-harmonic of the UHF signal. 21% locking range can be achieved to prevent PVT variations with -15 dBm injected power. Finally, radio-sensing interface co-design is explored. Taking the advantage of RC readout circuit and UWB pulse generator, the sensing information is directly extracted and transmitted in the time domain, exploiting high time-domain resolution UWB pulses. It eliminates the need of ADC of the sensor interface, meanwhile, reduces the number of bits to be transmitted for energy saving. The measurement results show that the proposed system exhibits 7.7 bits ENOB with an average relative error of 0.42%. / <p>QC 20160412</p>

Internet of things (IoT) generates massive amount of heterogeneous data, which should be efficiently utilized to support services in different domains. Specifically, data need to be supplied to services by understanding the needs of services and by understanding the environment changes, so that necessary data can be provided efficiently but without overfeeding. However, it is still very difficult for IoT to fulfill such data supply with only the existing supports of communication, network, and infrastructure; while the most essential issues are still unaddressed, namely the heterogeneity issue, the recourse coordination issue, and the environments’ dynamicity issue. Thus, this necessitates to specifically study on those issues and to propose a method to utilize the massive amount of heterogeneous data to support services in different domains. This dissertation presents a novel method, called the data-centric network of things (DNT), which handles heterogeneity, coordinates resources, and understands the changing IoT entity relations in dynamic environments to supply data in support of services. As results, various services based on IoT (e.g., smart cities, smart transport, smart healthcare, smart homes, etc.) are supported by receiving enough necessary data without overfeeding. The contributions of the DNT to IoT and big data research are: firstly the DNT enables IoT to perceive data, resources, and the relations among IoT entities in dynamic environments. This perceptibility enhances IoT to handle the heterogeneity in different levels. Secondly, the DNT coordinates IoT edge resources to process and disseminate data based on the perceived results. This releases the big data pressure caused by centralized analytics to certain degrees. Thirdly, the DNT manages entity relations for data supply by handling the environment dynamicity. Finally, the DNT supply necessary data to satisfy different service needs, by avoiding either data-hungry or data-overfed status.

The new technological phenomenon Internet of Things (IoT) is steadily growing and has become more incorporated into our daily lives. The technology can be found in a variety of applications in today's society and has helped to simplify and streamline tasks and processes. Analysts estimate that the market for IoT could potentially be worth 11 billion dollars by 2025. Large technology corporations are spending a vast amount of money to promote their IoT products, but we are also seeing companies which normally are not associated with IT making an entrance to make their products connected. During the fall of 2016 media reported about a big security breach within the IoT that affected security cameras and forced them to commit denial of service attacks. This event led us to take a closer look at the IoT and the security around the products. The aim of this study is to investigate how developers and security experts working with IoT perceive the current state of security and the possible threats and risks we face when using the technology. For this study we have used a qualitative approach with semi-structured interviews. A total of eight interviews were conducted equally divided between developers and security experts. Our results show that a common denominator between the respondents' answers was that the lack of standardization and platforms for IoT-applications is a problem. However, a unified security solution is currently unattainable due to the vast number of platforms present in IoT today. Therefore, the use of a standard or platform does not guarantee security. Also, with the increasing popularity of IoT, products from developers without the proper knowledge is becoming a serious security concern for the IoT.

<p>U doktorskoj disertaciji razmatrana je mogućnost lokalizacije proizvoda primenom tehnologija Interneta stvari. Postavljen je model za lokalizaciju proizvoda koji primenjuje RFID tehnologiju i bežične senzorske mreže. U okviru modela, predložen je i realizovan hibridni metod za lokalizaciju proizvoda koji kombinuje podatke dobijene metodom najbližih suseda i metodom optimizacije rojem čestica, a zatim i hibridni metod za lokalizaciju proizvoda koji kombinuje podatke dobijene u RFID sistemu i u bežičnoj senzorskoj mreži. Mogućnosti primene predloženog modela su eksperimentalno ispitane u simuliranim sistemima i u laboratorijskoj okolini sa industrijskim elementima..</p> / <p>This dissertation discusses the possibilities of product localization based on Internet of things technologies. A model for product localization has been proposed based on RFID technology and wireless sensor networks. Within the model, a hybrid localization method which combines outputs from nearest neighbours method and particle swarm optimization for product localization has been proposed and developed, followed by a hybrid localization method which combines data from RFID system and wireless sensor network. The application possibilities for the proposed model have been experimentally tested in simulated systems and in laboratory conditions with industrial elements.</p>

Aus der Einführung "Durch die Vernetzung von Produkten im Internet der Dinge / Internet of Things (IoT) und die damit einhergehende Verfügbarkeit von Daten, können nicht nur Produkte selbstständig agieren, reagieren und Aktionen auslösen, sondern auch externe Empfänger die von ihnen gelieferten Daten auswerten und für zusätzliche Services nutzen (Eisenhauer 2007, Abramovici et al. 2014). Dies birgt unter Anderem enorme Potentiale bei der Instandhaltung von technischen Anlagen (Wohlgemut 2007). Diese Anlagen oder Produktionsstätten sind in aller Regel komplexe Systeme, die aus einer heterogenen Landschaft von Subsystemen bestehen. Ohne vorhergehende Kenntnisse einer Maschine ist die Analyse oder Überprüfung solcher Systeme schwierig bis unmöglich. Weiterhin stehen die technischen Dokumentationen und Wartungshistorien bei solchen Tätigkeiten häufig nicht vollständig oder nur in Papierform vor Ort zur Verfügung, während der aktuelle Status der Anlage nicht mit den vorhandenen Informationen überlagert werden kann. ..."

Context-aware computing utilizes information about users and/or their environments in order to provide relevant information and services. To date, however, most context-aware applications only take advantage of contexts that can either be produced on the device they are running on, or on external devices that are known beforehand. While there are many application domains where sharing context is useful and/or necessary, creating these applications is currently difficult because there is no easy way for devices to share information without 1) explicitly directing them to do so, or 2) through some form of advanced user coordination (e.g., sharing credentials and/or IP addresses, installing and running the same software). This makes these techniques useful when the need to share context is known a priori, but impractical for the one time, opportunistic encounters which make up the majority of users’ lives. To address this problem, this thesis presents the Group Context Framework (GCF), a software framework that allows devices to form groups and share context with minimal prior coordination. GCF lets devices openly discover and request context from each other. The framework then lets devices intelligently and autonomously forms opportunistic groups and work together without requiring either the application developer or the user to know of these devices beforehand. GCF supports use cases where devices only need to share information once or spontaneously. Additionally, the framework provides standardized mechanisms for applications to collect, store, and share context. This lets devices form groups and work together, even when they are performing logically separate tasks (i.e., running different applications). Through the development of GCF, this thesis identifies the conceptual and software abstractions needed to support opportunistic groups in context-aware applications. As part of our design process, we looked at current contextsharing applications, systems, and frameworks, and developed a conceptual model that identifies the most common conditions that cause users/devices to form a group. We then created a framework that supports grouping across this entire model. Through the creation of four prototype systems, we show how the ability to form opportunistic groups of devices can increase users and devices’ access to timely information and services. Finally, we had 20 developers evaluate GCF, and verified that the framework supports a wide range of existing and novel use cases. Collectively, this thesis demonstrates the utility of opportunistic groups in context-aware computing, and highlights the critical challenges that need to be addressed to make opportunistic context sharing both practical and usable in real-world settings. The contributions of this thesis are: 1. A conceptual model, based on an analysis of prior literature, which describes the conditions under which users and/or devices form and work in groups. 2. An implementation of the Group Context Framework, which highlights the software abstractions and architecture needed to support all of the group types identified in our conceptual model. 3. A demonstration of the value of opportunistic groups in context aware computing, through the creation of four major systems and numerous smaller applications. 4. A validation of GCF’s robustness, through an examination of 65 ideas submitted by 20 developers. 5. An examination of the challenges associated with utilizing opportunistic groups in context-aware applications, based on our own experiences using GCF, as well as from issues raised by developers from academia and industry.

With the ever increasing number of Internet of Things devices going out on the market for consumers that are Zigbee certified there is a need for security testing. This is to make sure that security standards are upheld and improved upon in order to make sure networks are protected from unauthorized users. Even though a lot of research and testing has been done on the Zigbee key exchange mechanism, called Zigbee commissioning, improvements have still not been enough with severe vulnerabilities in consumer grade devices still existing today. The devices tested in this study use EZ-mode commissioning in order to exchange the network key between a Zigbee coordinator and a Zigbee end device in order to encrypt later communication after being paired.  By using a simple radio receiver and a packet capturing program such as Wireshark an eavesdropping attack was conducted in order to capture the network key. The experiment demonstrates that this is still a weak point as the network key was successfully captured using eavesdropping. The analysis of the results show that previous criticisms of Zigbee commissioning have still not fully been addressed and can be a potential weak point in networks that use Zigbee certified IoT products.

Recently, technology advancement has brought improvement in all the sectors, including the railway sector. The Internet of Things (IoT) based railway systems have immense potential to improve quality and systems that will enable more efficient, environmental friendly railway system. Many research brought innovations that offer enormous benefits for rail travel. The current research focuses on the railway industries, as they want to reap the benefits of IT concept such as Cloud Computing, Information Security, and Internet of Things (IoT). Railway industries are generating a large volume of data every day from different sources. In addition, machine and human interactions are rapidly increasing along with the development of technologies. This data need to be properly gathered, analysed and shared in a way that it is safe from different types of cyberattacks and calamities. To overcome smart devices’ and Cloud’s limitations, the new paradigm known as Fog computing has appeared. In which an additional layer processes the data and sends the results to the Cloud. Despite numerous benefits of Fog, computing brings into IoT-based environments, privacy and security issues remain the main challenge for its implementation. Hence, the primary purpose of this research is to investigate the potential challenges, consequences, threats, vulnerabilities, and risk management of data security in the railway infrastructure in the context of eMaintenance.

In today’s society blockchains and the Internet of things are two very discussed subjects this has led to thoughts about combining them by using a blockchain in Internet of things. This objective of this study has been to solve the problem which hashing algorithms is the best for a blockchain used in an Internet of things network. This have been done by first selecting a few hashing algorithms and setting up a scenario where a blockchain can be used in an Internet of things network. After that I specified what to compare, speed, input length and output length. The study has been conducted with the aid of literary studies about the hashing algorithms and a program that implements the algorithms and tests their speed. The study has shown that out of the selected hashing algorithms MD5, SHA-256, SHA3-256 with the conditions specified for the study that the hashing algorithm SHA3-256 is the best option if speed is not of the utmost importance in the scenario since it is from a newer standard and do not have a max input length. If speed is the very important in other words if SHA3-256 is to slow then SHA-256 would be best for the Internet of things network.

Orientador: João Pedro Albino / Banca: Maria Cristina Gobbi / Banca: Kelton Augusto Pontara da Costa / Resumo: Diariamente, somos expostos a radiação ultravioleta e sem que percebamos, podemos estar aptos a enfrentar problemas posteriores por causa das ações maléficas da ultravioleta sobre nossa pele, podendo desenvolver um câncer no futuro. Ações de prevenção são necessárias inclusive alertas visuais ou fontes de consultas. A Internet das Coisas é uma tecnologia em crescimento que permite que sensores sejam utilizados e que seus dados sejam coletados e armazenados. A integração com a Internet permite que as informações sejam disponibilizadas para consulta pública. Este relatório técnico apresentou o processo de elaboração de um dispositivo na plataforma Arduino e sua aplicação, a fim de apresentar os dados para análise de Raios Ultravioleta coletados online, disponibilizando-os para a comunidade, de forma a colaborar na divulgação de informações dos Índices de Radiação Ultravioleta para que as pessoas pudessem se prevenir contra os efeitos negativos advindo da exposição à tal radiação / Abstract: Every day, we are exposed to ultraviolet radiation and without realizing it, we may be able to face later problems because of the harmful actions of ultraviolet on our skin and may develop a cancer in the future. Prevention actions are required including visual alerts or sources of queries. The Internet of Things is a growing technology that allows sensors to be used and their data to be collected and stored. Integration with the Internet allows information to be made available for public consultation. This technical report presented the process of elaboration of a device in the Arduino platform and its application, in order to present the data for analysis of Ultraviolet Rays collected online, making them available to the community, in order to collaborate in the dissemination of information of the Indices of Ultraviolet radiation so that people could be warned against the negative effects of exposure to such radiation / Mestre