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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Software-related Energy Footprint of a Wireless Broadband Module

Asplund, Mikael, Thomasson, Anton, Vergara Alonso, Ekhiotz Jon, Nadjm-Tehrani, Simin January 2011 (has links)
Energy economy in mobile devices is becoming an increasinglyimportant factor as the devices become more advancedand rich in features. A large part of the energy footprint of amobile device comes from the wireless communication module,and even more so as the amount of trac increases.In this paper we study the energy footprint of a mobilebroadband hardware module, and how it is aected by software,by performing systematic power consumption measurements.We show that there are several cases where thesoftware does not properly take into account the eect thatdata communication has on the power consumption. Thisopens up for potential energy savings by creating better applicationsthat are aware of the energy characteristics of thecommunication layer.
2

Carbon and energy payback of variable renewable generation

Thomson, Rachel Camilla January 2014 (has links)
The continued drive to reduce Greenhouse Gas (GHG) emissions in order to mitigate climate change has led to an increase in demand for low-carbon energy sources, and the development of new technologies to harness the available energy in the wind, waves and tides. Many controversies surround these technologies, however, particularly with regards to their economic cost, environmental impacts and the implications of the variability of their output for security of the electricity supply. In order to make informed policy decisions on future developments of the electricity system, it is necessary to address these controversies and confirm the environmental, economic and social sustainability of these new renewable generators. This thesis specifically examines two key issues: whether new variable-output renewable energy generators actually deliver a net reduction in greenhouse gas emissions over their lifetimes, and whether they produce a viable energy return on energy investment. Although renewable energy sources are themselves ‘carbon free’, GHG emissions (and energy consumption) occur during the construction, maintenance and decommissioning of the generator infrastructure required to convert this energy into electricity. Furthermore, the variability of the output power from such generators has implications for the operation of the grid - there may be a requirement for additional reserve capacity and the increased part-loading of conventional plant is likely to reduce its operating efficiency. Carbon and energy paybacks are measures of the time required for a new renewable installation to offset these life cycle impacts. The work presented in this thesis examines both the life cycle impacts and the GHG emissions displacement of variable renewable generation, using Great Britain as a case study, in order to provide a basis for significantly more robust and reliable estimates of carbon and energy paybacks. The extensive literature survey concentrates on two key areas: current calculation methodologies and estimates for life cycle carbon and energy consumption of power generators; and the marginal emissions displacement of variable renewable generation. A detailed life cycle assessment of the Pelamis wave energy converter is presented, which sets the embodied carbon and energy in the context of the wider environmental impacts and includes an examination of the effect of different assumptions on the analysis results. In order to investigate the true emissions displacement of renewable generation, a historical analysis of real data from the National Grid was carried out, identifying the marginal displacement factor of wind power and taking into account the effect of the efficiency penalties of conventional plant. The findings of the analyses presented in this thesis are combined with information from the literature to examine the actual carbon and energy payback of existing renewable generation infrastructure on the British grid, and to provide detailed recommendations for future carbon and energy payback calculations.
3

Homo Colossus Energy Calculator / Homo Colossus Energikalkylator

Helander, Hugo, Tegelmo, Linus January 2020 (has links)
This thesis covers the creation of a series of questions that have the purpose of estimating the amount of energy that an individual uses over the course of a year. These questions are designed for a kiosk in an exhibition environment, and they will be used for an environmental project called Homo Colossus which will be presented at different exhibitions. The foundational energy values used in this thesis are from David JC MacKay. The main problem explored throughout this thesis is how we can, with as few questions as possible, give someone an estimation of their yearly energy consumption. To achieve this, we interviewed people with relevant experience and conducted a questionnaire to test the questions. The results from the test led to minor alterations in our questionnaire structure. / Denna uppsats handlar om skapandet av en samling frågor som har syftet att uppskatta mängden energi som en individ använder över ett år. Dessa frågor är designade för en kiosk i en utställningsmiljö, och kommer att användas för ett projekt som kallas för ‘Homo Colossus’ som kommer att presenteras på diverse utställningar. Huvudkällan för energivärdena i denna uppsats kommer ifrån David JC MacKay. Huvudfrågan som denna uppsats täcker är hur vi kan, med så få frågor som möjligt, ge en uppskattning av någons årliga energikonsumtion. För att uppnå detta, så intervjuade vi personer med relevant erfarenhet och skapade ett frågeformulär för att testa frågorna. Resultatet från testet ledde till små förändringar i strukturen av frågeformuläret.
4

Hur energi fotavtryck kan förmedlas genom interaktion i augmented reality / Conveying energy footprints through interaction in augmented reality

Pettersson, Isak, Rosenberg, Gabriel January 2020 (has links)
Global uppvärmning är ett av nutidens största hot mot mänskligheten. Idag syftar många projekt och initiativ till att minska utsläppen av CO2, bland annat genom att inspirera människor till att minska sina individuella utsläpp. Som en del av Homo colossus at Expo2020, ett projekt med målet att engagera och informera människor om hur vår livsstil påverkar vår planet, har ett första designförslag för en visuell augmented reality (AR) installation utvecklats. Mer specifikt ett fysiskt vykort som förmedlar ett energifotavtryck till läsaren och vars bud- skap är tänkt att förstärkas med interaktiva AR-element. AR är en relativt ny teknik med en enorm potential för framtiden och ett ämne där det finns stor efterfrågan på forskning om var tekniken kan appliceras. Denna studie har syftat till att vidare utforska installationer i utställningsmiljöer med fokus på AR som medium och vi har även undersökt hur man bör designa installationer med AR för att förmedla budskap genom interaktion. Detta har utforskats genom en Research through design metodik där idéskapande workshops, möten med experter och ett användartest på en utvecklad prototyp har utförts. Resultatet från studien visade på att det är viktigt med en personlig koppling till innehållet för att skapa reflektion kring energifotavtryck hos användaren. En stark koppling mellan de AR- element som visas och den energiförbrukning som de representerar visade sig även vara en stor faktor till hur effektivt budskapet togs emot hos användaren. AR-elementen visade vidare på en markant förbättring gällande engagemang och ökad förståelse hos användaren. Vi ser en stor framtida potential i AR som ett medium i att förmedla budskap och studien har likaså väckt en rad nya frågor inom ämnet som vi uppmanar kommande arbeten till att utforska vidare. / Global warming is one of humanity’s biggest threats. Today, many projects and initiatives aim to reduce CO2 emissions, among other things by inspiring people to lower their individual emission. As part of Homo colossus at Expo2020, a project with the goal of engaging and informing people about how our lifestyle affects our planet, a first design proposal for a visual augmented reality (AR) installation has been developed. More specifically, a physical postcard that conveys an energy footprint to the reader and whose message is intended to be reinforced with interactive AR elements. AR is a relatively new technology with enormous potential for the future and a topic where there is great demand for research on where the technology can be applied. This study aims to further explore installations in exhibition environments with a focus on AR as a medium. We have also explored how to design installations with AR to convey messages through interaction. This has been explored through a Research through design methodology where idea-generating workshops, meetings with experts and a user test on a developed prototype have been conducted. The results of the study showed that it is important to have a personal connection to the content in order to create a reflection on the energy footprint of the user. A strong link between the AR elements displayed and the energy consumption they represent also proved to be a major factor in how effectively the message was received by the user. The AR elements further showed a mayor improvement in commitment and increased understanding of the user. We see a great future potential in AR as a medium in conveying messages and the study has also raised a number of new issues within the subject that we encourage future studies to explore further.
5

Lightweight serverless protocols for the internet of things / Les protocoles de sécurité serverless légers pour l’internet des objets

Mtita, Collins 13 June 2016 (has links)
Les avancées technologiques permettent d'intégrer des capteurs et des modules de communication dans les objets du quotidien pour les rendre intelligents et faciliter leur intégration sur l'Internet. L'Internet du futur sera sans nul doute celui des objets connectés. Les objets connectés génèrent, collectent, stockent et partagent des informations entre eux et aussi avec les serveurs d'authentification centralisés. La plupart des informations collectées doivent être protégées pendant le stockage et le transfert. Par le passé, divers protocoles assurant une sécurité robuste basés sur la cryptographie asymétrique et d’autres sur la cryptographie symétrique ont été proposés dans la littérature. Du fait que les objets connectés possèdent de faibles capacités de calcul, de mémoire et d'énergie, et que l'accès au medium radio est très consommateur en ressources, les protocoles cryptographiques traditionnels ne sont pas adaptés aux objets connectés. Il y a lieu donc d'adapter ou de concevoir des protocoles propres et conformes à leurs exigences. Dans cette thèse, nous abordons les défis de sécurité et de vie privée pertinents aux systèmes pervasifs avec des contraintes de ressources strictes. Nous regardons les protocoles d'authentification serverless, qui sont des mécanismes d'authentification qui ne nécessitent pas la présence du serveur central au cours de la phase d'authentification entre deux objets connectés. Tout d'abord, nous fournissons les caractéristiques et les besoins pour les protocoles serverless. Grâce à ces besoins et caractéristiques, nous avons fait des recherches, des analyses complètes et des comparaisons des protocoles serverless existants en termes de sécurité, de vie privée et de performances. Nous examinons leurs capacités à résister à diverses attaques et leurs aptitudes à minimiser l’usage des ressources. Après quoi, notre objectif est de proposer des protocoles de sécurité serverless permettant aux objets de s’authentifier tout en garantissant efficacité, passage à l’échelle et efficacité énergétique, l'énergie étant une ressource très critique qui a une influence directe sur la durée de vie d’un objet connecté. Trois nouvelles contributions sont proposées dans cette thèse. Notre première contribution est un protocole léger serverless d'authentification mutuelle pour les objets connectés hétérogènes. La première contribution fournit trois avantages par rapport aux protocoles existants. Cette contribution répond aux exigences des systèmes pervasifs. La validation de notre proposition a été faite en utilisant l'outil AVISPA et la validation informelle en utilisant sécurité et de vie privée des jeux. Notre deuxième contribution comprend deux protocoles complémentaires dans le domaine des technologies RFID. Le premier protocole vise à l'authentification de masse entre un lecteur RFID et un groupe d'étiquettes tandis que le deuxième protocole effectue une recherche sécurisée pour une étiquette cible parmi un groupe d'étiquettes dans le voisinage du lecteur. Les deux protocoles proposés tiennent compte des contraintes de ressources des étiquettes RFID. Après une étude approfondie des protocoles serverless, nous avons proposé une troisième contribution, un guide pour la conception des protocoles serverless sécurisé et efficaces pour les systèmes pervasifs. Le guide contient six principes et six meilleures pratiques en vue d'élaborer des protocoles serverless. Le guide est destiné à aider à la conception de protocoles serverless efficaces, sécurisés et simples en évitant des erreurs couramment faites dans les protocoles existants / This thesis addresses the security and privacy challenges relevant to the resource constrained devices in the era of pervasive computing. Pervasive computing, a term coined by Schechter to describe the idea of computing services available anytime, anywhere and on demand, is characterized by seamless interactions between heterogeneous players in the Internet. This phenomenon allows intelligent chips, sensors or microcontrollers to be embedded into everyday objects to enable them generate, communicate and share information. Pervasive computing accelerates technological evolution by integrating small and resource constrained devices to the Internet arena, eventually opening doors to new services requiring seamless interactions and integrations with the existing technologies, infrastructures and services. The nature of the information generated, stored and shared by resource constrained devices may require proper security and privacy guarantees. Towards that end, the classical security solutions are not ideal candidates to solve the security and privacy challenges in pervasive systems for two reasons. First, classical security protocols require a lot of resources from the host devices while most of the pervasive devices have very strict resource constraints. Second, most classical security solutions work in a connected mode, which requires constant communication between devices and centralized servers for authentication and authorization purposes. However, pervasive devices may be working in isolated areas with intermittent network coverage and connectivity. Thus, it is ideal to come up with alternative solutions suitable for heterogeneous pervasive devices to smoothly interact, authenticate and securely share information. One of the suitable alternative solutions is the serverless protocols. The term “serverless protocol” refers to the mechanism of enabling centrally controlled devices to autonomously authenticate one another, or other heterogeneous devices, without an active participation of the centralized authentication or authorization servers. Serverless protocols prioritize on securing proximity communication between heterogeneous devices while optimizing on the little resources available. In this thesis, we tackle the challenges of pervasive systems by proposing lightweight and efficient serverless protocols for authenticating heterogeneous pervasive devices during proximity communication. Our proposed protocols derive their originality from the fact that they do not require the communicating parties to have prior relationships with each other, nor to have any previously shared authentication information with each other. Moreover, our proposed solutions incorporate context information to enforce automatic parameter expiry. This property is not supported by most of the earlier versions of the serverless protocol schemes, hence making them vulnerable to different attacks. Three novel contributions are proposed in this thesis. First, we propose a serverless lightweight mutual authentication protocol for heterogeneous devices. The first contribution includes a formal validation using the AVISPA tool. Second, we propose two complementing protocols using RFID (Radio-Frequency Identification) as a core technology. The first protocol performs mass authentication between an RFID reader and a group of tags and the second protocol performs a secure search for a target tag among a group of tags. The second contribution includes two formal validations; one is done using the AVISPA tool and the other is done using the CryptoVerif tool. After a thorough study of serverless protocols, we propose our third contribution, a concise guide on how to develop secure and efficient serverless protocols relevant to the pervasive systems
6

Textilproduktionens miljöpåverkan : en studie om koldioxidavtryck, vatten- ochenergianvändning mellan två hemtextil produkter i bomull från olika länder / The environmental impact of textile production : a study on carbon footprint, water andenergy use between two home textile products in cotton from different countries

Tran, Jenny, Nguyen, Linda January 2022 (has links)
Textil- och klädindustrin är identifierad som en av dem största bidragande faktorerna som frigör växthusgaser över hela världen. Produktionen har en lång och komplex försörjningskedja vilket redan från råvaruutvinning släpper ut enorma mängder växthusgaser. Den här kandidatuppsatsen går igenom hela försörjningskedjan för hemtextilsektorn vad gäller olika processer från fiber till färdiga produkter och deras miljöpåverkan. Den undersöker miljöpåverkan från olika stadier i textilprodukters livscykel från vaggan till graven. Uppsatsen belyser också konceptet och principerna för mätning av koldioxidavtryck, vatten och energianvändning för hemtextilprodukter, metoder för att mäta det och dess tillämpning i textilförsörjningskedjan. I produktens livscykelanalys beräknas avtrycket från resursutvinning (vagga) till fabriksporten (grind), i de faserna inkluderas försörjning av fiber, trim och förpackning, textilbearbetning, transporter i produktion, lagring och förpackning, samt distribution. Syftet med arbetet är att beräkna koldioxidavtryck, vatten- och energianvändning och jämföra mellan två påslakanset i 100% bomull tillverkade i två olika länder. Studien ämnar ge en bättre förståelse kring koldioxidutsläppen och miljöpåverkan som dessa produkter frigör under produktion. För att senare kunna jämföras, analyseras och föreslå eventuella förbättringar för att minska produktionens utsläpp. / The textile and clothing industry has been identified as one of the biggest contributing factors to greenhouse gas emissions worldwide. Production has a long and complex supply chain, which already emits enormous amounts of greenhouse gases from raw material extraction. This bachelor's thesis goes through the entire supply chain for the home textile sector in terms of various processes from fiber to finished products and their environmental impact. It examines the environmental impact from different stages in the life cycle of textile products from the cradle to the grave. The thesis also highlights the concept and principles for measuring carbon footprint, water and energy use for home textile products, methods for measuring it and its application in the textile supply chain. The product life cycle analysis calculates the footprint from resource extraction (cradle) to the factory gate (gate), in which phases supply of fiber, trim and packaging, textile processing, transport in production, storage and packaging, and distribution are included. The purpose of the work is to calculate the carbon footprint, water and energy use and compare between two duvet cover sets in 100% cotton made in two different countries. The study aims to provide a better understanding of the carbon dioxide emissions and environmental impact that these products release during production. In order to later be able to compare, analyze and suggest possible improvements to reduce production emissions.
7

Administrative building with low energy footprint / Administrativní budova s nízkou energetickou stopou

Slepánek, František January 2015 (has links)
The aim of this diploma thesis is trying to solve difficulties connected with administrative buildings. In this thesis we are talking about possibility that administrative building can have low energy footprint. Most of energy consumption of administrative building is not created by heating but mostly by cooling and by consumption of office equipment. That is why there have been used modern equipment of the building as well as automatic control of building equipment.

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