To my master's thesis I approached with the idea of functional simplicity in construction and without limitation of comfort of the object´s users. Residential house is located in a new development in Pávov near Jihlava, which is designed as a five-storey building that provides housing for people moving for work. This is why I designed it as a low cost construction, which mainly consists of one room apartments with a kitchen corner. The whole building is shaped as "L", where the ground floor serves as technical facility of the object, entrance, cellar and a covered parking space.The following four floors serve as residential. From the construction point of view I chose a suitable combination of materials and systems for overall pleasant use of the building.

The dissertation thesis deals with cryptographic protocols for secure authentication of communicating parties, which are intended primarily for low-cost devices used in Internet of Things. Low-cost devices represent computationally, memory and power constrained devices. The thesis focuses mainly on the possibilities of using mathematically undemanding cryptographic resorces for ensuring integrity of transmitted dat, authenticity of and secured transmission of data on low-cost devices. The main goals of the thesis focus on the design of new advanced cryptographic protocols for ensuring integrity of transmitted data, authenticity, confidentiality of transmitted data between low-cost devices and authenticity with non-repudiation of done events. The thesis describes proposal of three authentication protocols, one unilateral authentication protocol and two mutual authentication protocols. The thesis also describes proposals of two protocols for secured transmission of data between two devices, one protocol without a proof of receipt data and one protocol with proof of receipt data. In this thesis is also performed a security analysis and a discussion to proposed protocols.

Dans un contexte général d’augmentation de la demande énergétique et de préoccupation croissante face au réchauffement climatique et à la limitation des ressources naturelles, l’utilisation d’énergie solaire devrait augmenter. L’avenir des différentes technologies photovoltaïques dépend évidemment de leur rendement de conversion photovoltaïque et de leur coût mais aussi de la disponibilité des ressources. Les couches minces de kesterite, Cu2ZnSnS4 (CZTS), Cu2ZnSnSe4 (CZTSe) ou Cu2ZnSn(S,Se)4 (CZTSSe), composées d’éléments abondants dans la croûte terrestre se positionnent en candidat prometteur pour la conversion d’énergie solaire à grande échelle.Dans cette thèse, l’électro-dépôt, un procédé compatible avec des exigences industrielles de production, est utilisé pour déposer un précurseur de cuivre, étain et zinc sur des substrats de 15 × 15 cm2, de composition et épaissseur contrôlables. Ce précurseur est ensuite converti en semiconducteur par traitement thermique en présence de soufre ou de sélénium. Les couches ainsi formées de Cu-Zn-Sn-S ou Cu-Zn-Sn-Se, doivent être uniformes et présenter les propriétés appropriées (phases, composition, morphologie) pour la fabrication de cellules solaires à haut rendement. Le procédé de fabrication de la cellule solaire complète, notamment les étapes qui interviennent dans la formation de la jonction p-n (décapage chimique et dépôt de couche tampon) est également optimisé pour maximiser les rendements. A l’issue de ces optimisations, un rendement de 9.1% est obtenu pour une cellule solaire CZTSe, un nouveau record pour les cellules solaires à base de kesterite fabriquées par électro-dépôt. / Facing growing energy demand and increasing concerns about climate change and finite energy sources, solar energy use should increase. The future of the different photovoltaic technologies obviously depends on their power conversion efficiency and cost (summarized by the ratio cost per watt), but also on the elements availability. Thin films of earth-abundant kesterite, Cu2ZnSnS4 (CZTS), Cu2ZnSnSe4 (CZTSe) or Cu2ZnSn(S,Se)4 (CZTSSe), which can be manufactured with low-cost processes, are promising candidates for solar energy conversion at large scale.In this thesis, a copper tin and zinc precursor of controllable composition and thickness is electrodeposited on 15 × 15 cm2 substrates. Electrodeposition is a process compatible with high throughput low-cost and safety industry requirements. The precursor is converted into a semiconductor by thermal treatments in presence of sulfur or selenium. The resulting Cu-Zn-Sn-S or Cu-Zn-Sn-Se layers should be uniform and have adequate properties (phases, composition and morphology) to produce high efficient solar cells. Full device processing, including the pn junction formation steps (wet chemical etching and buffer layer deposition) is also investigated in order to maximize device efficiency. The best CZTSe solar cell exhibits a 9.1% powerconversion efficiency, setting a new record for kesterite solar cells produced by electrodeposition.

Department of Mining and Environmental Geology / MESC

We proposed and demonstrated the first account of large-area, semi-transparent, tandem photosensitive nanocrystal skins (PNSs) constructed on flexible substrates operating on the principle of photogenerated potential buildup, which avoid the need for applying an external bias and circumvent the currentmatching limitation between junctions. We successfully fabricated and operated the tandem PNSs composed of single monolayers of colloidal water-soluble CdTe and CdHgTe nanocrystals (NCs) in adjacent junctions on a Kapton polymer tape. Owing to the usage of a single NC layer in each junction, noise generation was significantly reduced while keeping the resulting PNS films considerably transparent. In each junction, photogenerated excitons are dissociated at the interface of the semi-transparent Al electrode and the NC layer, with holes migrating to the contact electrode and electrons trapped in the NCs. As a result, the tandem PNSs lead to an open-circuit photovoltage buildup equal to the sum of those of the two single junctions, exhibiting a total voltage buildup of 128.4 mV at an excitation intensity of 75.8 μW cm⁻² at 350 nm. Furthermore, we showed that these flexible PNSs could be bent over 3.5 mm radius of curvature and cut out in arbitrary shapes without damaging the operation of individual parts and without introducing any significant loss in the total sensitivity. These findings indicate that the NC skins are promising as building blocks to make low-cost, flexible, large-area UV/visible sensing platforms with highly efficient full-spectrum conversion.

With the advent of Internet of Things (IoT), an increasing number of devices start exchanging information. This puts emphasis on wireless sensor networks (WSNs) to facilitate the interaction with the environment in varied application scenarios such as, for example, building and home automation among others. In this context, a reliable communication is usually required, i.e., it is necessary to guarantee that packets arrive within a specified maximum delay or deadline. In addition, since nodes are usually battery-powered and deployed in large numbers, they must be cost-effective and economize on energy, which requires nodes to have a low complexity. In this context, unidirectional communication, i.e., where nodes either send or receive data, seems to be an interesting solution. Since no elaborate feedback mechanisms such as carrier sensing, acknowledgments and retransmissions schemes are possible, complexity, costs, energy consumption and communication overhead are reduced in a considerable manner. On the other hand, however, packet loss becomes more likely making such networks strongly unreliable. To overcome this predicament, two MAC (Medium Access Control) protocols are proposed, namely DEEP and RARE. These consist in nodes transmitting their data as sequences of redundant packets with carefully selected inter-packet separations leading to robust transmission patterns that enable reliable communication. In the case of DEEP, full (100%) reliability can be guaranteed, i.e., there is no data loss, which is particularly useful for safety critical applications. RARE, on the other hand, is designed for applications that tolerate some amount of data loss and can be configured to a reliability <100%, i.e., to a certain probability on successful data delivery. This allows improving other aspects of the network, such as energy consumption, communication delays, etc. In contrast to solutions from the literature, the proposed protocols do not pursue a best-effort approach, but rather provide an analytical framework to assess the performance (i.e., reliability, energy consumption, etc.) of the network. In addition, the proposed protocols are based on more general models that allow describing arbitrary node types with different deadlines and packet lengths leading to a provable higher performance. These and other benefits are illustrated by the means of extensive numerical experiments and simulations based on the OMNeT++ framework.

Esta investigación titulada “Ingreso de aerolíneas low cost al mercado peruano y su impacto en las aerolíneas comerciales tradicionales de rutas nacionales, años 2015-2018” tiene como objetivo analizar el efecto de las aerolíneas low cost con respecto a las tradicionales. Actualmente, estas últimas están ingresando al Perú con varias rutas nacionales, lo cual tiene como finalidad obtener una mayor participación en el mercado. Sin embargo, las aerolíneas tradicionales se mantienen en constantes cambios con su modelo de negocio para seguir compitiendo. La investigación se divide en cinco capítulos: En el Capítulo I se presenta el marco teórico y se explican los conceptos básicos, tales como las estructuras de mercado; las estrategias de fijación de precios; conceptos aeronáuticos; concepto de low cost; principales aerolíneas del Perú; ingreso de low cost (caso Perú) y costeo y tarifas de low cost. En el Capítulo II del plan de investigación se formula la problemática de la investigación, hipótesis y objetivos. En el Capítulo III que corresponde a la metodología de investigación, se detallan los tipos de investigación e instrumentos a utilizar. En el Capítulo IV del desarrollo de la investigación, se analiza la información cualitativa y cuantitativa. En el Capítulo V se presentan los análisis de resultados y se realiza el análisis de los instrumentos, concluyendo con la validación de la hipótesis general y específicas basados en los resultados obtenidos del análisis de correlación y entrevistas a especialistas. Finalmente, las conclusiones para todos aquellos que deseen analizar el impacto de las aerolíneas low cost. / This research entitled “Entry of low-cost controls to the Peruvian market and its impact on traditional commercial regulations of national routes, years 2015-2018” aims to analyze the effect that low-cost regulations have on traditional traditional ones. Currently, low-cost airlines are entering Peru with a wide variety of national routes, which has as obtaining a greater market share. However, traditional practices remain in constant changes with their business model to continue competing. The present work is divided into five chapters: Chapter I Theoretical framework, where the basic concepts will be explained, stories such as: Market Structures, according to Estevan (2013); Pricing strategies; Aeronautical concepts; Low cost concept; Main Airlines of Peru; Low cost income (case Peru) and Costing and low cost rates. Chapter II Research plan, the research problem, hypothesis and objectives are formulated. Chapter III Research methodology, which details the types of research and instruments to be used for the population. Chapter IV Research development, where qualitative and quantitative information is analyzed. Chapter V Analysis of results, the analysis of the instruments was carried out, concluding with the validation of the general and specific hypotheses based on the specific results of the correlation analysis and interviews with specialists. Finally, the conclusions for all those who wish to analyze the impact of low costs in the last year in Perú are detailed. / Tesis

The theme of this thesis is the air transport and its dramatic and dynamic development in the last twenty years. The key driving force behind this change was the deregulation of air agreements and liberalization of international markets, which took place in the seventies in the USA and in the nineties in Europe. This work addresses specific and general effects of deregulation and the development of air transport industry and aims to identify and analyze changes of its structures in space and time. One of the major and direct impacts and consequences of deregulation is that the free market allowed the emergence of new low-cost airlines, which significantly changed the structure and trends of air transport. The changes allowed for greater mobility of people, goods and capital, and also caused a partial change in consumer behaviour of individuals and institutions, and even more interconnected global economy. The source of data and information are primarily articles in professional journals written in English. Knowledge from particular analysis and research approaches to air traffic from the first part of this work is confronted with empirical research. This was based on the statistical data of air traffic in Germany, for each airport from 1991 to 2010 and verified the theoretical concepts of the general...

Carbon concrete polyacrylonitrile (PAN)/lignin-based carbon fiber (CF) composites are a new promising material class for the building industry. The replacement of the traditional heavy and corroding steel reinforcement by carbon fiber (CF)-based reinforcements offers many significant advantages: a higher protection of environmental resources because of lower CO2 consumption during cement production, a longer lifecycle and thus, much less damage to structural components and a higher degree of design freedom because lightweight solutions can be realized. However, due to cost pressure in civil engineering, completely new process chains are required to manufacture CF-based reinforcement structures for concrete. This article describes the necessary process steps in order to develop CF reinforcement: (1) the production of cost-effective CF using novel carbon fiber lines, and (2) the fabrication of CF rebars with different geometry profiles. It was found that PAN/lignin-based CF is currently the promising material with the most promise to meet future market demands. However, significant research needs to be undertaken in order to improve the properties of lignin-based and PAN/lignin-based CF, respectively. The CF can be manufactured to CF-based rebars using different manufacturing technologies which are developed at a prototype level in this study.

This study has looked at two separate locations, Malmö in Sweden, and Medellin in Colombia, and what the possibilities of rainwater harvesting are in those locations. The paper investigated data gathered by low-cost sensors in Malmö region, as well as sampling and measurements of rainwater collected in Malmö and Medellin, analysed by laboratories in both countries. Important data for the paper are quantity, quality, as well as environmental benefits and the economical perspective of rainwater harvesting. There are several steps that can be taken towards a more sustainable use of the Earth’s resources, and rainwater harvesting is included in the possibilities already at hand. But there is need for further development of monitoring and ways to qualify water for different purposes. It is possible to utilize rainwater for many things, and with that, ease the pressure on the local water supply infrastructure. This study has shown some important parts of that process, and that even low-cost sensors can help in gathering essential data for further evaluation of the usability of the rainwater. By collecting parts of the rainwater, flooding due to extensive downpour can be mitigated to some extent. Moreover, considering the low price of the sensors tested in this study, it is possible to use several low-cost sensors to determine the usability to some extent. Had the measurements rendered in values being too low compared to the laboratory results, the risk would have been greater. The consequence is that usable water could be regarded as not usable since the sensors returned an overall higher value compared to the laboratory results. Furthermore, the research found that the environmental benefit can be substantial. But there are more positive implications when gathering water for usage locally. For example, the water supply can become more distributed and with that, less prone to cause events such as water leaks, polluted water, and extreme events that have rendered an unserviceable infrastructure.