In this thesis, new algorithms for formation control of multi agent systems (MAS) based on continuum mechanics principles will be investigated. For this purpose agents of the MAS are treated as particles in a continuum, evolving in an n-D space, whose desired configuration is required to satisfy an admissible deformation function. Considered is a specific class of mappings that is called homogenous where the Jacobian of the mapping is only a function of time and is not spatially varying. The primary objectives of this thesis are to develop the necessary theory and its validation via simulation on a mobile-agent based swarm test bed that includes two primary tasks: 1) homogenous transformation of MAS and 2) deployment of a random distribution of agents on to a desired configuration. Developed will be a framework based on homogenous transformations for the evolution of a MAS in an n-D space (n=1, 2, and 3), under two scenarios: 1) no inter-agent communication (predefined motion plan); and 2) local inter-agent communication. Additionally, homogenous transformations based on communication protocols will be used to deploy an arbitrary distribution of a MAS on to a desired curve. Homogenous transformation with no communication: A homogenous transformation of a MAS, evolving in an space, under zero inter agent communication is first considered. Here the homogenous mapping, is characterized by an n x n Jacobian matrix ( ) and an n x 1 rigid body displacement vector ( ), that are based on positions of n+1 agents of the MAS, called leader agents. The designed Jacobian ( ) and rigid body displacement vector ( ) are passed onto rest of the agents of the MAS, called followers, who will then use that information to update their positions under a pre- iv defined motion plan. Consequently, the motion of MAS will evolve as a homogenous transformation of the initial configuration without explicit communication among agents. Homogenous Transformation under Local Communication: We develop a framework for homogenous transformation of MAS, evolving in , under a local inter agent communication topology. Here we assume that some agents are the leaders, that are transformed homogenously in an n-D space. In addition, every follower agent of the MAS communicates with some local agents to update its position, in order to grasp the homogenous mapping that is prescribed by the leader agents. We show that some distance ratios that are assigned based on initial formation, if preserved, lead to asymptotic convergence of the initial formation to a final formation under a homogenous mapping. Deployment of a Random Distribution on a Desired Manifold: Deployment of agents of a MAS, moving in a plane, on to a desired curve, is a task that is considered as an application of the proposed approach. In particular, a 2-D MAS evolution problem is considered as two 1-D MAS evolution problems, where x or y coordinates of the position of all agents are modeled as points confined to move on a straight line. Then, for every coordinate of MAS evolution, bulk motion is controlled by two agents considered leaders that move independently, with rest of the follower agents motions evolving through each follower agent communicating with two adjacent agents.

La tesi doctoral es proposa conèixer quines són les feines i responsabilitats que exerceixen els treballadors i col•laboradors de les ràdios de proximitat catalanes, a més de les relacions que s’estableixen entre ells. Es tracta de les figures professionals que fan possible el funcionament i la programació d’aquests mitjans, de manera que la vessant humana de la comunicació és un element transversal de la investigació. La recerca defineix les funcions d’una i altra figura professional, fet que implica, entre d’altres, desglossar la seva relació amb el mitjà. Els treballadors i col•laboradors exerceixen tasques i assoleixen responsabilitats que poden coincidir o que estan diferenciades, i que es vinculen amb el lloc que ocupen dins l’organigrama de cada ràdio. Per conèixer aquesta realitat s’ha creuat la metodologia quantitativa de l’enquesta amb la recerca qualitativa de les entrevistes en profunditat. Amb la investigació s’han acotat els límits mediàtics i territorials en les emissores de ràdio locals i comarcals de Catalunya i s’ha definit la situació laboral en aquests mitjans, centrant-la en les figures dels treballadors i dels col•laboradors. / La tesis doctoral se propone conocer cuales son las tareas y responsabilidades que ejercen los trabajadores y colaboradores de las radios de proximidad catalanas, además de las relaciones que se establecen entre ellos. Se trata de las figuras profesionales que hacen posible el funcionamiento y la programación de estos medios, de forma que la vertiente humana de la comunicación es un elemento transversal de la tesis. La investigación define las funciones de una y otra figura profesional, hecho que implica, entre otros aspectos, desglosar su relación con el medio. Los trabajadores y colaboradores ejercen tareas y asumen responsabilidades que pueden coincidir o que están diferenciadas, y que se vinculan con el puesto que ocupan dentro del organigrama de cada radio. Para conocer esta realidad se ha cruzado la metodología cuantitativa de la encuesta con la cualitativa de las entrevistas en profundidad. Con la tesis se han acotado los límites mediáticos y territoriales en las emisoras de radio locales y comarcales de Catalunya y se ha definido la situación laboral en estos medios, centrándola en las figuras de los trabajadores y de los colaboradores. / The thesis tries to discover which are the tasks and responsibilities that the workers and contributors in Catalan radios take part in, and also the relations between them. These are the professional figures that make possible the operation and programming of the media, so that the human side of communication is a cross-cutting element of the investigation. The research defines the functions of the different professional figures, which implies, among others, the breakdown their relationship with the media. Workers and contributors exercise tasks and responsibilities that may coincide or that are differenced, and that are linked with the place they occupy in the organization chart structure of each radio. To know this situation it has been crossed the quantitative methodology of the survey with the qualitative research interviews. With the research have been confined media and territorial limits on local and regional radio stations in Catalonia and has defined the employment situation in the media, focusing on the figures of workers and collaborators.

Studiens ämne handlar om förståelsen av risk under en hälsokris utifrån lokal riskkommunikation. Covid-19-pandemin utgör en stor hälsorisk för människor över hela världen. Tidigare forskning visar att riskkommunikation behöver nå och påverka människor så att de kan skydda sig själva mot de pågående riskerna. Därför är det viktigt att studera hur människor uppfattat riskerna med covid-19 från deras lokala kommunikatörer.  Syftet med studien är att undersöka hur studenter på eftergymnasial nivå i Jönköpings kommun förstod riskerna med covid-19 och avsåg att agera utifrån sin riskförståelse, utifrån Jönköpings kommuns riskkommunikation under våren 2020. Den specifika perioden som studeras är mellan 15 mars och 19 juni 2020. För att uppnå studiens syfte har fyra fokusgruppsintervjuer med studenter på eftergymnasial nivå i Jönköpings kommun genomförts och analyserats med en teoribaserad tematisk metod. Det teoretiska ramverket som använts för den tematiska analysen består av Uses and Gratifications Theory, Protection Motivation Theory och Theory of Planned Behavior.  Resultaten av studien visar att studenterna uppfattade riskerna med covid-19 som allvarliga, men att de inte haft avsikten att fullt ut ändra sina beteenden för att undvika riskerna. Deras riskförståelse berodde däremot inte på kommunikation från Jönköpings kommun, eftersom få av studenterna hade tagit del av deras kommunikation under våren 2020. Istället hade de använt källor som Folkhälsomyndigheten och nyhetssidor. Dessutom upplevde studenterna kommunikationen från kommunen som oseriös och bristfällig gällande viktig information. Resultaten visar att studenterna upplevde Jönköpings kommuns kommunikation om beteendeförändringar för att undvika risker som vag och svår att förstå, vilket inte bidrog till deras avsikt att ändra beteende / The subject matter of this study is risk perception during a health crisis based on local risk communication. The covid-19-pandemic is a mayor health crisis for citizens all over the world. Prior science has shown that risk communication needs to reach and affect citizens so they can protect themselves from the ongoing risks. Therefore, it is important to study how citizens have perceived the risks of covid-19 from their local communicators.    The purpose of this study is to examine how students on a post-gymnasium level in Jönköping municipality understood the risks of covid-19 and intended to act upon their perception of the risks based on the risk communication from Jönköping municipality, during the spring of 2020. The specific period examined is between the 15th of March and the 19th of June 2020. In order to achieve the aim, four focus group interviews with students on a post-gymnasium level in Jönköping have been conducted and analyzed through theoretically based thematic analysis. The theoretical framework used for the analysis of the focus group interviews consists of the Uses and Gratifications Theory, Protection Motivation Theory and Theory of Planned Behavior.  The results of the study show that the students perceived the risks of covid-19 as severe, but that they did not intend to fully change their behavior in order to avoid the risks. However, their risk perception was not based on the communication from Jönköping municipality since very few of them had seen their communication during the spring of 2020. Instead, they used sources like the national health authority and news channels. Additionally, the students found the communication from the municipality to be too lighthearted and lacking in vital information. The results show that the students found the municipality’s’ communication about behavioral change as vague and difficult to understand, which didn’t have an impact on their intention to behavioral change.