This thesis deals with the fractional (1+)-order filters. The proposed filters operate in the current-mode. The derivation of the filters has been achieved using a third-order aproximation of the coresponding fractional-order transfer functions. It also describes active elements such as universal current conveyor, current follower and operational transconductance amplifier. In the end of this thesis some new circuit solutions of the fractional-order filter are proposed. Then the proposed filters are realized and experimentally measured.

The Theory of Situational Leadership, the core of the thesis, has become nowadays one of the intensively studied area in Sociology of management. The primary goal to be accomplished here in this thesis is to examine leadership styles of leaders in the optical business in the Czech Republic and to determine if the leaders are effective when exercise leading the followers, all with regard to Blanchard's and Hersey's Situational Leadeship Theory. The main part of the thesis consists of empirical study which focuses on leaders and their ledearship styles in optical organizations as well as their effectiveness in leading team of followers. The quantitative survey tool modified by author so can be used in czech environment will be introduced in the methodological part of the thesis. The theoretical assumptions should appropriately illustrate the analytical results obtained by the research.

L’objectif de cette thèse est de développer et étudier des modèles mathématiques d’échanges économiques, basés sur la flexibilité de la demande, entre fournisseurs et consommateurs d’électricité. D’une part, des fournisseurs d’électricité offrent des prix dépendant de l’heure de consommation. D’autre part, des consommateurs adaptent leur usage, minimisant leur facture et le désagrément lié aux changements de consommation induits. La structure de ces problèmes correspond à des problèmes d’optimisation bi-niveau. Trois types de modèles sont étudiés. Tout d’abord, l’interaction entre un fournisseur et un opérateur de smart grid est modélisée par un problème à un seul meneur et un seul suiveur. Pour cette première approche, le niveau de détails du suiveur est particulièrement élevé, et inclut notamment une gestion stochastique de la production distribuée. La meilleure réponse d’un fournisseur dans un modèle à plusieurs meneurs et plusieurs suiveurs fait l’objet de la seconde partie de la thèse. Celle-ci intègre aussi la possibilité d’avoir des agrégateurs comme suiveurs. Deux nouvelles méthodes de résolution reposant sur la sélection d’équilibres de Nash entre suiveurs sont proposées. Enfin, dans une troisième et dernière partie, on se focalise sur la recherche d’équilibres non coopératifs pour ce modèle à plusieurs meneurs et plusieurs suiveurs.Tous les problèmes abordés dans cette thèse le sont non seulement d’un point de vue théorique, mais également d’un point de vue numérique / The objective of this thesis is to develop and study mathematical models of economical exchanges between energy suppliers and consumers, using demand-side management. On one hand, the suppliers offer time-of-use electricity prices. On the other hand, energy consumers decide on their energy demand schedule, minimizing their electricity bill and the inconvenience due to schedule changes. This problem structure gives rise to bilevel optimization problems.Three kinds of models are studied. First, single-leader single-follower problems modeling the interaction between an energy supplier and a smart grid operator. In this first approach, the level of details is very high on the follower’s side, and notably includes a stochastic treatment of distributed generation. Second, a multi-leader multi-follower problem is studied from the point of view of the best response of one of the suppliers. Aggregators are included in the lower level. Two new resolution methods based on a selection of Nash equilibriums at the lower level are proposed. In the third and final part, the focus is on the evaluation of noncooperative equilibriums for this multi-leader multi-follower problem.All the problems have been studied both from a theoretical and numerical point of view.

Retention of qualified and experienced employees is the greatest challenge faced by nonprofit organizations. Using transformational leadership theory, the purpose of this single-case study was to explore strategies used by managers of nonprofit organizations to increase employee retention. The population for this study included 3 managers of one nonprofit organization in Texarkana, Texas, with tenure of at least 2 years. These managers had successfully implemented retention strategies to retain qualified and experienced employees for more than 2 years. Collected data included semistructured, face-to-face interviews and from archived documents that pertained to employee retention in nonprofit organizations. The data analysis process comprised 5 steps: compiling, disassembling data for coding, reassembling, interpreting, and reporting data themes. The use of member checking and methodological triangulation increased the trustworthiness of interpretations. The 2 themes that emerged from this study were motivational incentives and effective communication. The implications for positive social change in the nonprofit sector include sustaining the workforce by retaining qualified and experienced employees. With less employee turnover, nonprofit leaders may experience real cost savings. Nonprofit leaders may find the cost savings beneficial in extending available funds for services to local communities.

Inspired by the trend of automated homes, this thesis examines the possibility of designing a cheap and autonomous robot that will water plants effectively at home. Many existing solutions are cumbersome and not sufficiently effective, often due to flexibility and risk of over watering. Therefore this thesis examines a wheel based approach. In order to achieve the best possible results, the soil water content was measured, as opposed to a time-based approach where the user sets a timer to decide how often the plants are watered. This thesis also examines the advantages, and disadvantages of a capacitive moisture sensor versus a resistive moisture sensor, as well as effects of depth of penetration for the sensors. Controlled using an Arduino Uno, the robot was programmed to follow a line with IR-sensors, drive using differential steering, and had the ability to drive in reverse. It was able to identify a pot, read the moisture level of the soil, water it, and continue the loop. However, it was not completely autonomous as it is incapable of refilling the water tank – or recharging the batteries. It was stated that the resistive sensor was most suited to be used in the robot due to the relatively reliable results at increased depth. The results at deeper penetration were expected, as the moisture increased with depth when not recently irrigated. The capacitive sensor showed somewhat ambiguous results. The results showed higher water content deeper into the soil, compared to recently irrigated soils. / Inspirerade av trenden om automatiserade hem grundar sig detta arbete i möjligheten att skapa en billig och självgående robot som effektivt vattnar plantor i hemmet. Då många nuvarande lösningar är besvärliga och inte tillräckligt effektiva har detta kandidatarbete undersökt ett tillvägagångssätt som innefattar en robot byggd på en plattform med hjul. För att uppnå en effektiv bevattning grundar sig processen i fuktighetsnivån hos jorden plantorna sitter i, istället för en annars vanlig tidsbaserad bevattningsprocess. Därmed undersöker arbetet även fördelar och nackdelar med resistiva och kapacitiva jordfuktighetssensorer. Rapporten undersöker och redogör hur påverkan av djupet sensorn penetrerar jorden påverkar datan om jordens fuktighet. Kontrollerad av en Arduino Uno följde roboten en utsatt linje med hjälp av IR-sensorer och en motordrivare som implementerade både differentialstyrning och möjligheten att köra motorer i motsatt riktning. Den slutgiltiga roboten kunde med hjälp av ultraljudssensorer upptäcka en kruka, läsa av fuktighetsnivån i jorden, vattna och sedan fortsätta slingan. Däremot var den inte helt självkörande då den saknade förmågan att fylla på vattentanken och ladda sina batterier själv. Det konstaterades att den resistiva sensorn var bäst lämpad, tack vare dess tillförlitliga mätningar vid varierande djup. Den resistiva sensorns utslag vid djupare mätningar var förväntade, då den torra jorden ökade i fuktighet och den nyligen bevattnade jorden visade fortsatt fuktigt. Däremot visade den kapacitiva sensorn något tvetydiga resultat vid djupa mätningar, då de torra krukorna framstod som fuktigare än de nyligen bevattnade.

The use of unmanned aerial vehicles (UAV), so-called drones, has been growingrapidly in the last decade. Today, they are used for, among other things, monitoring missions and inspections of places that are difficult for people to access. Toefficiently and robustly execute these types of missions, a swarm of drones maybe used, i.e., a collection of drones that coordinate together. However, this introduces new requirements on what solutions are used for control and navigation. Two important aspects of autonomous navigation of drone swarms are formationcontrol and collision avoidance. To manage these problems, we propose four different solution algorithms. Two of them use leader-follower control to keep formation, Artificial PotentialField (APF) for path planning and Control Barrier Function (CBF)/ExponentialControl Barrier Function (ECBF) to guarantee that the control signal is safe i.e.the drones keep the desired safety distance. The other two solutions use an optimal control problem formulation of a motion planning problem to either generate open-loop or closed-loop trajectories with a linear quadratic regulator (LQR)controller for trajectory following. The trajectories are optimized in terms of timeand formation keeping. Two different controllers are used in the solutions. Oneof which uses cascade PID control, and the other uses a combination of cascadePID control and LQR control. As a way to test our solutions, a scenario is created that can show the utilityof the presented algorithms. The scenario consists of two drone swarms that willtake on different missions executed in the same environment, where the droneswarms will be on a direct collision course with each other. The implementedsolutions should keep the desired formation while smoothly avoiding collisionsand deadlocks. The tests are conducted on real UAVs, using the open sourceflying development platform Crazyflie 2.1 from Bitcraze AB. The resulting trajectories are evaluated in terms of time, path length, formation error, smoothnessand safety.  The obtained results show that generating trajectories from an optimal control problem is superior compared to using APF+leader-follower+CBF/ECBF. However, one major advantage of the last-mentioned algorithms is that decision making is done at every time step making these solutions more robust to disturbancesand changes in the environment.

This was a qualitative, multiple-site case study that examined the leadership styles before, during, and after a major organizational transition. The purpose of the study was to determine if a major organizational transition affected the leadership styles of organizational leaders. It also sought to determine how the major organizational transitions affected the climate and the culture of the three organizations studied. The participants for this multiple-site case study were a hospital, a manufacturing plant, and a public library in Central Ohio. The organizational leaders were chosen because they had gone through a major organizational transition in the previous two years. Each leader then chose three followers based on two criteria. Two of the three had to be subordinates who reported directly to the organizational leader and one who had to be the leader's administrative assistant. The participants were interviewed using a guided interview; therefore, qualitative methods were used. Data analyses were completed by the process of data reduction, data display, and conclusions drawn from the data display (constant comparison). I discovered the leaders' styles remained somewhat consistent throughout the organizational transition. All three leaders used comparable methods of dealing with the transition. The leaders had the ability to identify the organizational issues that necessitated the transition, sought alternative actions, and then proceeded with the best alternatives. The climate and culture of each organization was more affected by the transition than the leader. [I started this research thinking the leaders might be the ones most affected.]

Digital transformation is a challenging undertaking for most businesses. It disrupts prior organizational processes and structures and affects the way leadership is manifested. Leadership literature has historically focused a great deal on the leader’s perspective, even so in discussions concerning digital transformation. Scholars agree that followers are an essential part to leadership, yet their perspective is often overlooked in the discussion. This study focuses on the follower experience in digital transformation. Based on a review of extant literature, I structure a theoretical framework comprising several concepts such as; AIT, context, leadership style, digital mindset and digital fluency. I have collected data through semi-structured group-interviews and have adopted a narrative analysis to interpret the data collected from 21 respondents, from three different sectors, that have experienced digital transformation as followers. The insights from the study deepen our understanding of the follower’s perspective of digital transformation and highlight three areas of import for a successful digital transformation; trust, stress and work-life balance. I conclude the study by outlining directions for future research. / Digital transformation är en utmaning för de flesta företag. Det är disruptivt och utmanar tidigare organisatoriska processer och strukturer och påverkar hur ledarskap manifesteras. Ledarskapslitteraturen har historiskt fokuserat på ledarperspektivet, även så i diskussioner om digital transformation. Forskare är överens om att följare är en viktig del av ledarskap, men deras perspektiv förbises ofta i diskussionen. Denna studie fokuserar på följarupplevelsen i digital transformation. Baserat på en genomgång av befintlig litteratur, strukturerar jag ett teoretiskt ramverk som omfattar flera begrepp så som; AIT, kontext, ledarstil, digitalt mindset och digitalt flyt. Jag har samlat in data genom semistrukturerade gruppintervjuer och har antagit en narrativ analys för att tolka data som samlats in från 21 respondenter, från tre olika sektorer, som har upplevt digital transformation som följare. Insikterna från studien fördjupar vår förståelse av följarens perspektiv på digital transformation och lyfter fram tre viktiga områden för en framgångsrik digital transformation; tillit, stress och balans mellan arbete och privatliv. Jag avslutar studien med att föreslå riktningar för framtida forskning

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