Les nanofils d’or ultrafins sont des objets fascinants présentant une morphologie quasi 1D, leur diamètre n’excédant par 2 nm pour une longueur micrométrique. Les quelques 30 atomes qui composent la section de ses fils sont principalement des atomes de surface, permettant d’envisager des applications de type capteurs. De plus, l’anisotropie de forme unique pourrait permettre un confinement électronique unidimensionnel, menant à de nouvelles propriétés physiques. Nous avons réalisé une étude fondamentale de la synthèse et réaliser une première étude de transport sur une assemblée de nanofils.La première partie du manuscrit, divisée en quatre chapitres, consiste en l’étude du mécanisme de croissance de ces nanofils ultrafins. Suite à une analyse détaillée des modèles proposés, nous introduisons la technique de diffusion des rayons X aux petits angles (SAXS) utilisée pour nos études mécanistiques. Le chapitre 3 est consacré à l’étude de la synthèse de nanofils en milieu confiné. Contrairement aux postulats précédents, un suivi cinétique in-situ par SAXS nous a permis de montrer que la phase lamellaire n’intervenait pas dans la croissance des objets, voir même qu’elle était détrimentaire à leur formation. Le dernier chapitre présente la synthèse en milieu isotrope. Un mécanisme de croissance efficace où les sphères jouent le rôle de germe est avancé. L’auto-organisation des fils en solution suivant une phase hexagonale appuie l’hypothèse d’une stabilisation des fils par une double couche d’oleylamine et de chlorure d’ammonium. Un mécanisme de croissance analogue aux mécanismes proposés pour les bâtonnets d’or dans l’eau est donc proposé.La deuxième partie du manuscrit, divisée en trois chapitres, consiste en une caractérisation des propriétés de transport électronique dans ces nanofils d’or ultrafins. Nous dressons, dans un premier temps, un bilan des différents régimes de transport observés au sein de nano-objets de basse dimensionnalité. Suite aux étapes indispensables de dépôt et de connexion, le troisième chapitre présente les premières mesures de transport effectuées sur des assemblées de nanofils d’or faiblement couplées. Nous mettons ainsi en évidence, grâce à une étude sur une large gamme de températures et de tensions de polarisation, un transport de charge coopératif dans le cadre d’un régime de blocage de Coulomb. / Ultra-narrow gold nanowires are captivating objects with a quasi-1D morphology, with a diameter lower than 2 nm and a micrometric length. The few 30 atoms which compose the wire section are mainly surface atoms, allowing to consider applications such as sensors. Moreover, the unique anisotropic shape may permit a one-dimensional electronic confinement, leading to new physical properties. We conducted a fundamental study of the synthesis and a preliminary transport study on an assembly of nanowires.The first part of the manuscript, divided into four chapters, consist of the growth mechanism study of these ultra-narrow gold nanowires. Further to a detail analysis of the proposed models, we present the small angle X-rays scattering (SAXS) technique used for our mechanistic studies. The third chapter deals with the study of the nanowires synthesis in a confined environment. Unlike the previous postulates, a in-situ kinetic monitoring by SAXS allow us to point out that the lamellar phase was not involved in the objects’ growth, even more that it was detrimental for their formation. The last chapter presents the synthesis in an isotropic system. An efficient growth mechanism where the spheres act as seeds is advanced. The wires’ self-assembly in solution in a hexagonal super-lattice supports the hypothesis of wire stabilization by a bilayer of oleylamine and oleylammonium chloride. Therefore, a growth mechanism similar to the one proposed in the case of gold nanorods in water is proposed.The second part of the manuscript, divided into three chapters, consist in a characterization of the electronic transport properties in these ultra-narrow gold nanowires. At first, we report on the different types of transport observed low-dimensionality nano-objects. Further to the necessary deposit and connection steps, the third chapter presents the first transport measurements performed weakly coupled assemblies of gold nanowires. We highlight, through a study on a wide range of temperatures and bias voltages, a cooperative charges transport through a Coulomb blockade regime.

L’engouement actuel pour les applications de type réseaux de capteurs sans-fil ou internet des objets (IoT) relance la nécessité, alors initiée par les applications mobiles, de concevoir des émetteurs-récepteurs radio à basse consommation. Dans ce contexte, l’objet des travaux de thèse est de proposer des techniques de réduction de la consommation des récepteurs radio tout en minimisant l’impact sur leur architecture de manière à pouvoir adapter leur consommation aux besoins de performance.Pour ce faire, l’utilisation intermittente du convertisseur analogique numérique (ADC) a, dans un premier temps, été étudiée puis celle-ci a été généralisée à l’ensemble du récepteur. Pour chacune de ces approches, une modélisation de la dégradation des performances en termes de taux d’erreur (BER) a été confrontée à une estimation de la réduction de la consommation engendrée. Par ailleurs, l’impact de l’ajout de modules spécifiques aux techniques proposées est décrit à l’aide de résultats concernant leurs complexités et leurs consommations. L’ensemble de ces résultats s’inscrit pleinement dans le domaine de recherche des récepteurs adaptatifs pour lesquels les performances sont adaptées au canal de transmission en temps réel.Finalement, une technique de compensation digitale des défauts de quadrature a été proposée, rendant possible l’utilisation d’une PLL moins énergivore mais avec des performances dégradées. Cette technique utilise une recherche par dichotomie des poids de compensation des défauts de quadrature, lui permettant de converger suffisamment rapidement pour pouvoir réaliser la compensation sur une portion connue du message reçu et ainsi éviter une perte d’information. / The recent craze for the Wireless Sensor Networks (WSN) and the Internet of Things (IoT) applications boosts the necessity, previously introduced by the mobile applications, to design low power transceivers. In this context, the purpose of this thesis is to propose some techniques to reduce the power consumption of RF receivers while minimizing the impact on their architecture in order to be able to adapt their power consumption to the required performances.To do so, the study of the intermittent use of the analog-to-digital converter (ADC) is firstly proposed and then extended to the whole receiver. In each case, the degradation of the receiver performances in terms of bit error rate (BER) is compared to an estimate of the obtained decrease of the power consumption. Moreover, the complexity and the overhead power consumption of the modules involved in the processing of the proposed techniques are also estimated and discussed. All these results are part of the field of research called “adaptive receiver” that tries to adapt the receiver performances to its environment in real time.Finally, a digital compensation technique of the quadrature imbalances was proposed. It allows using a less energy-consuming PLL but with degraded quadrature performances and compensating the mismatches in the digital domain. This technique uses a dichotomic search of the compensation weights allowing a fast convergence in order for the compensation to be done during the reception of a known portion of the received message and therefore avoiding a loss of information.

Many students change their choice of secondary school programme or fail to complete their studies which results in a great cost to society or personal costs for the student. The purpose is to examine the experiences of two groups of upper secondary school students regarding their choice of upper secondary school programme. The questions we wanted answers to were: what influenced the student’s choice of study, what support did the students receive from comprehensive school and what might have caused them to choose another programme. The study was carried out in two focus groups where one of the groups was made up of students who had chosen the “right” programme and the other made up of students who had chosen the “wrong” programme. One thing that influenced the student’s choice of upper secondary school programme was whether or not the programme provided eligibility to higher studies which they had heard from primary school and parents was a choice that would give them many possibilities in the future. It appeared that there had not been much of a guidance process for developing career management skills which could have given the students support in reflecting over their transition to upper secondary school. The students’ interests and the parents and people near the students influenced the students’ choices. The study shows that students needed a longer guidance process and a clearer understanding of its purpose. Narrow and wide guidance varied depending on a student’s comprehensive school. They would have needed a better description of the consequences such as what study demands were required for the programme and what moving or commuting would mean in practice.

Since the introduction of the Riemann integral in the middle of the nineteenth century, integration theory has been subject to significant breakthroughs on a relatively frequent basis. We have now reached a point where integration theory has been thoroughly researched to a point where one has to delve quite deep into a particular subject in order to encounter open conjectures. In education the Riemann integral has for quite some time been the standard integral in elementary analysis courses and as the complexity of these courses incrementally increase the more general Lebesgue integral eventually becomes the standard integral.  Unfortunately, in the transition from the Riemann integral to the Lebesgue integral there are certain topics of pure theoretical interest which to a certain extent are neglected. This is particularly the case for topics regarding the inverse relationship between differential and integral calculus and the integration of exceedingly complicated functions which for example might be of a highly oscillatory nature. From an applied mathematician's point of view, the partial neglection of these topics in the case of highly problematic functions might be justified in the sense that this theory is unnecessary for modeling most problems that appear in nature. From a theoretician's point of view however this negligence is unacceptable. Consequently, there are alternative integrals which give rise to theories which one can use in an attempt to study these aforementioned topics. An example of such an integral is the Henstock–Kurzweil integral, which can be developed in a rather similar manner to that of the Riemann integral.  In this thesis we will develop the Henstock–Kurzweil integral in order to answer some of the questions which to a certain extent are beyond the scope of the Lebesgue integral while using rather basic proof techniques from complex analysis and measure theory. In addition to that we extended various properties of the Lebesgue integral to the Henstock–Kurzweil integral, in particular when it comes to Lebesgue's fundamental theorem of calculus and the basic convergence theorems of the Lebesgue integral.

This paper explores the future of Artificial Intelligence (AI) and how it can be used by organised crime orterrorist organisations. It exploresthe fundamentals of AI, its history and how its use is affecting the waypolice operate. The paper shows how the development rate of AI is increasing and predicts how it willcontinue to evolve based on different parameters. A study of different types of AI shows the different usesthese systems have, and their potential misuse in the near future. By using the six pillars approach, aprediction concerning AI and the development of Artificial General Intelligence (AGI) is explored, andits ramifications to our society. The results show that in a world with AGI, AI-enabled crime as we knowit would cease to exist, but up until that point, the use of AI in crime will continue to impact our daily livesand security / Denna uppsats undersöker framtiden för AI och hur den kan användas av organiserad brottslighet ellerterroristorganisationer. Den utforskar grunderna för AI, dess historia och hur dess användning påverkarpolisens verksamhet. Uppsatsen visar hur utvecklingshastigheten för AI ökar och förutsäger hur denkommer att fortsätta utvecklas baserat på olika parametrar. En studie av olika typer av AI visar de olikaanvändningsområdena dessa system har och deras potentiella missbruk inom en snar framtid. Genom attanvända metoden sex pelare undersöks en förutsägelse om AI och utvecklingen av Artificiell Generellintelligens (AGI) och dess konsekvenser för vårt samhälle. Resultaten visar att i en värld med AGIkommer AI-aktiverad brottslighet som vi vet att den skulle upphöra att existera, men fram till den tidenkommer användningen av AI i brottslighet att fortsätta att påverka vårt dagliga liv och säkerhet.

Under våren 2020 konstaterades att coronaviruset Covid-19 är en pandemi. Detta medförde restriktioner inom skolvärlden som innebar en påtvingad förändring att bland annat studie- och yrkesvägledningen nu skulle ske digitalt. Med frågeställningarna ”Hur ser utvecklingen av den snäva och vida digitala vägledningen ut för studie- och yrkesvägledare inom gymnasieskolan”, ”Vilka för- och/eller nackdelar ser studie- och yrkesvägledare inom gymnasieskolan med digital vägledning?” samt ”Vilka önskemål finns hos studie- och yrkesvägledare inom gymnasieskolan kring eventuell kompetensutveckling när det gäller digital vägledning?” är vår förhoppning att vi ska uppnå studiens syfte. Syftet är att undersöka huruvida verksamma studie- och yrkesvägledare på kommunala gymnasieskolor i sju kommuner i norra Sverige anser sig besitta de kompetenser som behövs för att anpassa sig till ett eventuellt nytt arbetssätt med digital vägledning, samt om och i så fall hur detta har utvecklats i samband med Covid-19. En kvalitativ forskningsmetod med semistrukturerade intervjuer användes för insamling av data. Vi har analyserat resultatet med hjälp av karriärteorin Social Cognitive Career Theory (SCCT), och dess begrepp upplevd självförmåga, förväntat utfall och personliga mål. Av denna studie framgår att den snäva vägledningen fungerar relativt väl digitalt, medan den vida vägledningen upplevs som en utmaning. I resultaten lyfts fördelar med digital vägledning som effektivitet och tillgänglighet samt nackdelar som brist på personlig kontakt. Det framgår även att videosamtal föredras framför telefonsamtal bland de studie- och yrkesvägledare vi intervjuat, samt att efterfrågan på kompetensutveckling uppfattas som minimal. Framledes kan informanterna se att en kombination av traditionell och digital vägledning är att föredra, även när det blir möjligt att genomföra mer vägledning på plats. / In the spring of 2020, it was declared that the coronavirus Covid-19 is a pandemic. This led to restrictions in the school generally that meant a forced change that, among other things, career guidance would now take place digitally. With the questions ”What is the development of the narrow and wide digital guidance for career counsellors in upper secondary school?”, ”What advantages and/or disadvantages do career counsellors in upper secondary school see with digital guidance?” and ”What are the wishes of career counsellors in upper secondary school regarding possible competence development in digital guidance?” our hope is that we will achieve the purpose of the study. The aim is to investigate whether active career counsellors at municipal upper secondary schools in seven municipalities in northern Sweden consider themselves to possess the skills needed to adapt to a possible new way of working with digital guidance, and if so how this has developed in connection with Covid-19. A qualitative research method with semi- structured interviews was used for data collection. We have analyzed the results using Social Cognitive Career Theory (SCCT), and its concept of self efficacy, outcome expectations and personal goals. This study shows that the narrow guidance works relatively well digitally, while the wide guidance is perceived as a challenge. Our results highlights benefits of digital guidance such as efficiency and accessibility as well as disadvantages such as lack of personal contact. Other results indicates, among other things, that video calls are preferred to telephone calls by the career counsellors when it comes to career guidance, and that the demand for competence development is perceived as minimal. In the future, the informants can see that a combination of traditional and digital guidance is preferable, even when it becomes possible to implement more face-to- face guidance.

La minería es considerada un trabajo de alto riesgo debido a la exposición a diferentes peligros, alineado al trabajo de investigación se menciona la inestabilidad de los tajeos que está estrictamente relacionado a los daños que pueden ocasionar a los colaboradores y como señala el MINEM, entre el 2015 y 2020, del total de accidentes ocurridos en la minería, el 28.7 % corresponden a accidentes relacionados a desprendimiento de rocas, deslizamiento de bloques y derrumbes totales. Esto evidencia la necesidad de realizar evaluaciones geomecánicas en todos los niveles de la minería para ejecutar trabajos seguros y mantener la continuidad operativa. Por consiguiente, el presente trabajo de investigación se enfoca en determinar la dimensión geométrica óptima del tajeo N°1 de la Unidad Minera Debra Luz, de modo que la evaluación de cada superficie del tajeo sea estable y de esa manera señalar que el tajeo en general es seguro para la operación. El escenario de la investigación es en vetas angostas, característica que eleva el nivel de importancia del aporte puesto que la técnica a usar se ha implementado generalmente en métodos de explotación de grandes dimensiones. La técnica a usar será el Método Gráfico de Estabilidad de Mathews que permite evaluar mediante dos parámetros de ingreso, Número de estabilidad (N´) y Radio Hidráulico (RH), si el diseño propuesto se encuentra en una zona estable o no. El N´ es un factor asociado al macizo rocoso, valor constante, y el RH es una variable relacionada con las dimensiones del tajeo. Además, en el desarrollo de la investigación interviene el uso del Modelo Numérico de Elementos Finitos para determinar el esfuerzo de compresión inducida máxima y el factor de seguridad asociado al tajeo N°1 que indica si la labor es estable o no. El valor del ensayo de compresión uniaxial de la roca intacta de la caja techo de la galería SE es 150.3 MPa. Según Gonzales de Vallejo et al. (2002), este valor se encuentra en el rango considerado roca muy dura. La constante “k” para el caso de estudio se obtuvo igual a 1.55 que significa que la mayor ocurrencia de falla en el tajeo podría deberse a los esfuerzos horizontales. La dimensión optima que mantiene estable el tajeo es de 1.25 x 25 x 30 m, donde cada superficie del tajeo fue evaluada mediante el gráfico de estabilidad. Se obtuvo valores de factores de seguridad mayores a 1.3 mediante el modelo numérico, siendo estable. / Mining is considered a high-risk job due to exposure to different hazards, In line with the research work, mention is made of the instability of the stopes that is strictly related to the damage that can be caused to collaborators and, as the MINEM says, between 2015 and 2020, of the total number of mining accidents, 28.7 % relate to accidents related to rock fall, block slip and total landslides. This shows the need for geomechanical assessments at all levels of mining to perform safe work and maintain operational continuity. Therefore, this research paper focuses on determining the optimal geometric dimension of the N°1 stope of Debra Luz Mining Unit, so that the assessment of each stope surface is stable and thus indicate that the stope in general is safe for operation. The research scenario is in narrow veins, a characteristic that raises the level of importance of the contribution because the technique to use has generally been implemented in methods of exploitation of large dimensions. The technique to use will be the Mathews Stability Graph Method that allows to evaluate by two input parameters, Stability Number (N ) and Hydraulic Radius (RH), whether the proposed design is in a stable area or not. N is a factor associated with the rock mass, constant value, and the RH is a variable related to the stope dimensions. In addition, the research involves the use of the Finite Element Numerical Model to determine the maximum induced compression stress and the safety factor associated with the N°1 stope that indicates whether the work is stable or not. The value of the uniaxial compression test of the intact rock of the SE gallery hanging wall is 150.3 MPa. According to Gonzales de Vallejo et al. (2002), this value is in the range considered very hard rock. The constant "k" for the case study was obtained equal to 1.55 which means that the greatest occurrence of failure in the stope could be due to horizontal stresses. The optimal dimension that keeps the stope stable is 1.25 x 25 x 30 m, where each surface of the stope was evaluated using the stability graph. Values of safety factors greater than 1.3 were obtained using the numerical model, being stable. / Tesis

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This thesis is concentrated on the Angle / Direction of Arrival (A/DOA) estimation and Beamforming techniques that can be used in the current and future engineering applications such as tracking of targets, wireless mobile communications, radar systems, etc. This thesis firstly investigates different types of AOA and beamforming techniques. A comprehensive comparison between the common AOA algorithms is performed to evaluate the estimation accuracy and illustrate the computational complexity of each algorithm. The effect of mutual coupling between the radiators and the impact of the position-error of the antenna elements on the estimation accuracy is also studied. Then, several new efficient AOA methods for current wireless localisation systems are proposed. The estimation accuracy and computational complexity are compared with well-known AOA methods over a wide range of scenarios. New methodologies for Covariance Matrix (CM) sampling are proposed to enhance and improve operational performance without increasing the computational burden. A new beamforming algorithm is proposed and implemented on a compact mm-Wave linear and planar antenna arrays to enhance the desired signal and suppress the interference sources in wireless communication systems. The issue of asset tracking in dense environments where the performance of the Global Positioning System (GPS) becomes unavailable or unreliable is addressed in the thesis as well. The proposed solution uses a low-profile array of sensors mounted on a finite conducting ground. A compact-size omnidirectional spiral sensor array of six electrically small dual-band antenna elements was designed to operate in the 402 and 837 MHz spectrum bands. For the lower band, a three-element superposition method is applied to support the estimated AOA whereas six sensors are considered for the higher band. An efficient and low complexity Projection Vector (PV) AOA method is proposed. An Orthogonal Frequency Division Multiplexing (OFDM) modulation is integrated with the PV technique to enhance the estimation resolution. The system was found to be suitable for installation on top of vehicles to localise the position of assets. The proposed system was tested to track non-stationary objectives, and then two scenarios were investigated: outdoor to outdoor and outdoor to indoor environments using Wireless In-Site Software. The results confirm that the proposed tracking system works efficiently with a single snapshot. / Higher Commission for Education Development (HCED) in Iraq Basra Oil Company Ministry of Oil

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