Cette thèse porte sur la visibilité de groupes qualifiés d’extrémistes sur internet. Si plusieurs études ont décrit les différents usages des technologies numériques par des groupes radicaux et la manière dont internet serait un catalyseur de radicalisation, peu d’études ont cherché à analyser la relation constitutive entre un dispositif technique et des militants extrémistes. L’objectif de la thèse est de renouveler le modèle de la visibilité médiatisée de groupuscules qualifiés d’extrémistes, en tenant compte des reconfigurations mutuelles entre les plateformes numériques et le groupe militant. Sur le plan théorique, cette recherche se situe à l’intersection de la théorie de l’acteur-réseau, des software studies et des travaux de Lucy Suchman (2007) sur les dynamiques de reconfigurations mutuelles et permanentes des relations entre humains et machines. Basée sur l’étude du cas de l’État islamique, l’analyse s’ancre dans des données provenant d’un terrain de recherche de type ethnographique, collectées sur un an et demi. L’enquête est composée d’une observation non participante menée sur plusieurs plateformes numériques exploitées par le groupe jihadiste, de l’archivage et l’analyse des traces en ligne, ainsi que d’un corpus documentaire. Nos résultats contribuent premièrement à une meilleure compréhension de la visibilité des groupes qualifiés d’extrémiste sur les plateformes numériques, en démontrant qu’elle est relationnelle, technicisée et conflictuelle. Notre étude fait tout d’abord ressortir qu’on assiste à une complexification du tableau de la visibilité. La visibilité en ligne de l’État islamique nécessite un vaste réseau d’acteurs, tels que spécialistes des médias, militants, spécialistes en cybersécurité et botnets. La visibilité mêle ainsi des procédés hors-ligne et en ligne, décentralisés et centralisés. L’analyse des pratiques quotidiennes de visibilité montre que le travail d’apparence des militants de l’État islamique suit un objectif d’amplification et d’abondance de leur flux informationnel. Le but est d’inonder les plateformes de réseaux sociaux de contenus pro État islamique, afin de mener une « guerre médiatique ». Par ailleurs, les résultats suggèrent que la visibilité est complexe en raison des séries de contraintes et de forces ennemies qui contrecarrent le projet en ligne de l’État islamique, tel que la modération de leurs contenus. Parallèlement, notre étude montre que la présence de ces usagers a redessiné la régulation de ces technologies en les rendant plus contraignantes. Enfin, nos résultats dévoilent que les militants de l’État islamique refusent l’assujettissement face aux suspensions répétées dont ils font l’objet. Pour limiter les effets négatifs de la modération, le collectif travaille activement à mettre en place des tactiques de résistance. Dans un second temps, la thèse s’intéresse aux formes de visibilité que cette médiation technique entre les militants et les plateformes numériques configure. Nous proposons le concept de visibilité technicisée pour rendre compte de la visibilité en ligne des opinions politiques. Ce type de visibilité se fonde sur l’incessant déploiement d’une raison technique. En cela, la visibilité devient une activité spécialisée qui exploite les dimensions techniques et automatisées des technologies numériques, avec leurs normativités propres. Si la visibilité technicisée confère aux utilisateurs du pouvoir pour assurer leur visibilité, la thèse émet certaines réserves quant à la valeur réelle de ce faire-voir. Elle montre que, dans la quête d’efficacité et d’abondance qui la caractérise, ce type de visibilité technicisée généralise un ensemble de comportements nuisibles et de procédures trompeuses pour exprimer une opinion politique. Révélatrices de nouvelles formes de domination et d’asymétrie, nous plaidons qu’elle pourrait à terme contraindre le jeu démocratique. / This thesis focuses on the visibility of extremist groups on the internet. While several studies have focused on describing the different uses of digital technologies by radical groups and the way the internet would operate as a catalyst for radicalization, few studies have sought to analyze the constitutive relationship between the technical apparatus and the militant extremist. The objective of the thesis is to renew the visibility model of groups classified as extremists, taking into account the mutual reconfigurations between digital platforms and the militant groups. At a theoretical level, our study is situated at the intersection of actor-network theory (ANT), software studies and Lucy Suchman’s work (2007) on the dynamic reconfiguration of mutual and permanent relationships between humans and machines. Based on the case study of the Islamic State, this analysis, lasting one and a half years, was anchored in data from an ethnographic research field. The survey consists of non-participant observation of several digital platforms exploited by the jihadist group, online archiving and analysis of online traces, as well as a documentary corpus. Our results contribute to better understanding how groups qualified as extremist develop their visibility on digital platforms, by emphasizing that it is relational, technical and conflictual. First of all, our study demonstrates the evolution to a more complex development of the resources used to obtain visibility. The online visibility of the Islamic state requires a vast network of actors, such as media specialists, activists, cybersecurity specialists and botnets. For this reason, offline and online, decentralized and centralized processes are combined. The analysis of their daily practices shows that the work of Islamic state militants to obtain visibility strive at amplification and abundance of their information flow. Their goal is to inundate social media platforms with their contents, conducting a “media war”. Furthermore, the results obtained suggest that developing visibility is complex due to a series of constraints and enemy forces that thwart the Islamic State project, such as moderation of contents as an example. At the same time, our study shows that the presence of this type of users has resulted in the redesign of the regulation of these technologies, making them more restrictive. Finally, the results reveal that the Islamic state militants are actively working to put in place resistance tactics in order to limit the negative effects of that moderation. In a second step, the thesis focuses on the forms of visibility evolving from this technical mediation between activists and digital platforms. We suggest the concept of technical visibility to highlight the online visibility of political opinions. This type of visibility is based on the deployments of a technical rationality. Therein the creation of visibility becomes a specialized activity using the technical as well as mechanized dimensions of digital technologies, each with their own mode of normativity. If technical visibility gives users the possibility to develop their visibility, the thesis expresses certain reservations as to the real value of this “ faire-voir ”. It shows that this type of technical visibility, due to its characteristic quest for efficiency and abundance of information, generalizes bulk, aggressive, or deceptive activity. This results in new forms of domination and asymmetry. We therefore argue that it could jeopardize democracy.

Cette recherche vise à explorer l’organisation complexe et la structure actuelle de la scène Hip-hop underground à Montréal, afin d’expliquer les dynamiques sociales et relations de pouvoir régulant les interactions entre mainstream et underground. Dans une démarche d’étude de cas, nous avons rencontré les artistes-rappeurs des deux collectifs montréalais Kalmunity et Urban Science. Nous avons ainsi observé que ces collectifs sont le lieu d’une forme d’institutionnalisation de la scène. En l’absence de lieux dédiés à la culture, ils permettent la centralisation de ses acteurs et produisent un système de normes et de pratiques sociales partagées dans cette communauté. La scène Hip-hop à Montréal est organisée autour d’un enjeu de visibilité, articulant ses dynamiques sociales et logiques relationnelles. Si les collectifs limitent l’accès à la scène par un système de normes et de conditions d’accès, les médias mainstream quant à eux contrôlent l’accès à une audience de masse en imposant des règles propres à l’univers médiatique. Deux formes de visibilité s’opposent donc : une visibilité underground et sociale structurée par les collectifs, reposant sur la réputation à l’intérieur d’un groupe restreint d’interconnaissances, face à une visibilité mainstream et médiatique, fondée sur le principe de célébrité, propulsée par les médias. Enfin, les scènes underground et mainstream montréalaises ne valorisent pas les mêmes sources d’autorité quant à leurs pratiques sociales et artistiques. Le pouvoir représente pour les artistes underground une forme de domination s’exerçant par l’intermédiaire des médias, qu’ils refusent car jugée extérieure à la scène. À l’inverse, les collectifs représentent pour les artistes une autorité légitime car exercée à l'intérieur de leur communauté, et par conséquent adaptée à la réalité de leurs pratiques artistiques. / This study examines the current organization of the underground Hip-hop scene in Montreal and its power relations. To understand its dynamics, tensions and competition, we investigate the complex structure of the underground scene. Approaching this research as a case study, we met the artists-rappers from the two Montreal’s collectives Kalmunity et Urban Science. We then noticed that the collectives become institutions of the underground scene. With no actual locations dedicated to Montreal's Hip-hop culture, the collectives themselves embody a symbolic space where social actors can gather and create a hub for the network of professionals within the underground scene through a system of rules and social and artistic practices. The underground scene is hinged on the main issue of visibility, organizing the social dynamics and relational logics. We observe two types of visibility : an underground and social visibility structured around the collectives, based on reputation inside a restricted group of artists, facing a mainstream and mediatic visibility, built on fame and propelled by the media. Finally, the underground artists regard power as a form of domination by the media. They refuse the media injonctions seen as extrinsic to the scene. Conversely, the collectives represent a legitimate authority for underground artists, practiced inside their restricted community, therefore coherent to their artistic practices.

This diploma thesis deals with the analysis of selected properties of horizontal road marking (HRM). In terms of anti-skid properties measurements are made to determine the longitudinal friction coefficient, the coefficient of adhesion under different conditions and skid resistance of HRM. Measurements of anti-skid properties are supplemented by measurement of retroreflection of HRM. The theoretical part describes the current state of the issue, general characteristics of horizontal road marking and quantities measured in this thesis (friction and adhesion). The practical part consists of description of used measuring devices, custom solution and results analysis. The solution consists of the description of the measured samples, their preparation, subsequent measurement and a detailed description of the method of measured data evaluation. Data analysis is based on comparison of results obtained from individual sample groups and on comparison of measured values among themselves. The thesis is supplemented with photo documentation and video footage.

This diploma thesis is covering the coverage path planning problem for autonomous robotic lawn mower in an area, which is fully defined before and is not changing. It contains a review of the currently used methods and an implementation of a software with a graphic user interface, which is capable of generating optimalized path.

[EN] In this thesis, we consider two problems: we first explore the application of visibility graphs for describing the orbits of a discrete dynamical system that is governed by a fractional version of the logistic equation. We also study how to use this type of graphs to study response time series from the perspective of psychology. The preliminaries and introduction of these visibility graphs are presented in Chapter 1, where we revisit some basic facts from network science related to them. In the first part of this thesis, we analyze a phenomenon of mathematical nature. Wu and Baleanu introduced a fractional discrete dynamical system inspired by the fractional difference logistic equation. In order to study the trajectories of this model under this perspective of network science, in Chapter 2, we first review the most used fractional derivatives (Riemann-Liouville, Caputo, and Gründwald-Letnikov). Later, we show how to consider discrete fractional derivatives. Within our work, we present an alternative way of deducing the governing equation with respect to the one shown by Wu and Baleanu. We revisit the Wu-Baleanu equation in Chapter 3, focused on the visibility graphs of trajectories generated under different values of the scaling factor and the fractional exponent. We also study the existing connections between these parameters and the fitting with the degree distribution of the corresponding visibility graphs. When chaos is present, we link them with the exponent obtained when fitting the degree distribution to a power-law of the form x^(¿¿). With this approach, we provide an integrated vision of the dynamics of a family of fractional discrete dynamical systems that cannot be obtained from single Feigenbaum diagrams computed for each scaling factor and fractional exponent. We also connect the power-law exponent of the degree distribution fitting with the Shannon entropy of the visibility graphs degree distribution. In the second part, we analyze the response times of students to a binary decision task from the perspective of network science. We analyze the properties of the natural visibility graphs associated with their reaction time series. We observe that the degree distribution of these graphs usually fits a power-law distribution p(x) = x^(¿¿). We study the range in which parameter ¿ occurs and the changes of this exponent with respect to the age and gender of the students. Besides, we also study the links between the parameter ¿ and the ex-Gaussian distribution parameters that best fits each subject's response times. Finally, we outline some conclusions and perspectives of future research in both parts in Chapter 6. / [ES] En esta tesis, hemos considerado dos problemas: primero exploramos la aplicación de los grafos de visibilidad para describir las órbitas de un sistema dinámico discreto que está gobernado por una versión fraccionaria de la ecuación logística. Además, también estudiamos cómo usar este tipo de grafos para estudiar series temporales de tiempos de respuesta desde una perspectiva psicológica. Los preliminares, así como una introducción a estos grafos de visibilidad, se presentan en el Capítulo 1, donde revisitamos algunos hechos básicos de la ciencia de redes relacionados con dichos grafos. En la primera parte de esta tesis, analizamos un fenómeno de naturaleza matemática. Wu y Baleanu introdujeron un sistema dinámico discreto fraccionario inspirado en la ecuación logística con derivadas fraccionarias. Con el propósito de estudiar las trayectorias de este modelo desde la perspectiva de la ciencia de redes, en el Capítulo 2, primero revisamos las derivadas fraccionarias más utilizadas (Riemann-Liouville, Caputo y Gründwald-Letnikov). Posteriormente, mostramos cómo considerar derivadas fraccionarias discretas. En nuestro trabajo, presentamos una forma alternativa de deducir la ecuación gobernante con respecto a la presentada por Wu y Baleanu. Revisitamos la ecuación de Wu-Baleanu en el Capítulo 3, centrado en los grafos de visibilidad de trayectorias generadas a partir de distintos valores del factor de escala y del exponente fraccionario. También estudiamos la existencia de conexiones entre estos parámetros y el ajuste de la distribución de los grados de los correspondientes grafos de visibilidad. Cuando el caos está presente, los enlazamos con el exponente obtenido al ajustar la distribución de los grados a una ley de potencias de la forma x^(¿¿). A través de este enfoque, proporcionamos una visión integrada de la dinámica de una familia de sistemas dinámicos discretos fraccionarios que no se pueden obtener a partir de diagramas de Feigenbaum individuales calculados para cada factor de escala y exponente fraccionario. Además, relacionamos el exponente de la ley de potencias del ajuste de la distribución de grados con la entropía de Shannon de la distribución de grados de los grafos de visibilidad. En la segunda parte, analizamos el tiempo de respuesta de un grupo de estudiantes que realizaron una tarea de decisión binaria desde la perspectiva de la ciencia de redes. Estudiamos las propiedades de los grafos de visibilidad natural asociados con sus correspondientes series de tiempos de respuesta. Observamos que la distribución de los grados de estos grafos normalmente sigue una distribución ley de potencias p(x) = x^(¿¿). Analizamos el rango en el cual el parámetro ¿ se mueve y los cambios de este exponente con respecto a la edad y el sexo de los estudiantes. Por otro lado, también estudiamos la relación entre el parámetro ¿ y los parámetros de la distribución ex-Gaussiana que mejor se ajusta al tiempo de respuesta de cada sujeto. Finalmente, destacamos algunas conclusiones y perspectivas de investigación futura en ambas líneas de trabajo en el Capítulo 6. / [CAT] En aquesta tesi, hem considerat dos problemes: primer explorem l'aplicació dels grafs de visibilitat per a descriure les òrbites d'un sistema dinàmic discret que està governat per una versió fraccionària de l'equació logística. A més a més, també estudiem com emprar aquest tipus de grafs per a analitzar sèries temporals de temps de resposta des d'una perspectiva psicològica. Els preliminars, així com una introducció a aquests grafs de visibilitat, es presenten al Capítol 1, on revisitem alguns fets bàsics de la ciència de xarxes relacionats amb ells. En la primera part d'aquesta tesi, analitzem un fenomen de naturalesa matemàtica. Wu i Baleanu van introduir un sistema dinàmic discret fraccionari inspirat en l'equació logística amb derivades fraccionàries. Amb el fi d'estudiar les trajectòries d'aquest model des d'una perspectiva de la ciència de xarxes, en el Capítol 2, primer revisem les derivades fraccionàries més utilitzades (Riemann-Liouville, Caputo i Gründwald-Letnikov). Posteriorment, mostrem com considerar derivades fraccionàries discretes. Al nostre treball, presentem una forma alternativa de deduir l'equació governant respecte a la presentada per Wu i Baleanu. Revisitem l'equació de Wu-Baleanu al Capítol 3, focalitzat en els grafs de visibilitat de trajectòries generades a partir de valors diferents del factor d'escala i de l'exponent fraccionari. També estudiem l'existència de connexions entre aquests paràmetres i l'ajust de la distribució dels graus dels corresponents grafs de visibilitat. Quan el caos hi és, els enllacem amb l'exponent que hem obtés en ajustar la distribució dels graus a una llei de potències de la forma x^(¿¿). Des d'aquesta perspectiva, proporcionem una visió integrada de la dinàmica d'una família de sistemes dinàmics discrets fraccionaris que no es poden obtenir a partir de diagrames de Feigenbaum individuals calculats per a cada factor d'escala i exponent fraccionari. A més a més, relacionem l'exponent de la llei de potències de l'ajust de la distribució de graus amb l'entropia de Shannon de la distribució de graus dels grafs de visibilitat. A la segona part, analitzem el temps de resposta d'un grup d'estudiants que realitzaren una tasca de decisió binària des del punt de vista de la ciència de xarxes. Estudiem les propietats dels grafs de visibilitat natural associats amb les seues corresponents sèries temporals de temps de resposta. Observem que la distribució dels graus d'aquests grafs normalment segueix una distribució llei de potències p(x) = x^(¿¿). Analitzem el rang en què el paràmetre ¿ es mou i els canvis d'aquest exponent respecte a l'edat i el sexe dels estudiants. D'altra banda, també estudiem la relació entre el paràmetre ¿ i els paràmetres de la distribució ex-Gaussiana que millor fita el temps de resposta de cada subjecte. Finalment, destaquem algunes conclusions i perspectives d'investigació futura en ambdues línies de treball en el Capítol 6. / Mira Iglesias, A. (2021). Applications of Visibility Graphs for the representation of Time Series [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/176012 / TESIS

In den letzten Jahren erfreuen sich komplexe Netzwerke einer zunehmenden Beliebtheit, um Zusammenhänge und Strukturen in hoch-dimensionalen Datensätzen zu analysieren. Im Unterschied zu vielen anderen Forschungsgebieten wurden sie jedoch selten auf Paläoklima-Daten angewandt, obwohl die steigende Anzahl an veröffentlichen Zeitreihen die Nutzung effizienter Methoden multivariater Analyse ermöglicht. Die Resultate der wenigen Studien, in denen Netzwerkmethoden und Paläoklima-Daten kombiniert wurden, sind außerdem geprägt von niedriger Robustheit und hohen Unsicherheiten. Dies steht im Zusammenhang zu der niedrigen Anzahl und Auflösung der Zeitreihen als auch den Unsicherheiten, die den meisten Paläoklima-Rekonstruktionen zu eigen sind. In dieser Doktorarbeit schlage ich verschiedene Wege vor, um diese Probleme zu überwinden, indem verlässlichere, quantitative Resultate ermöglicht werden, unter anderem indem die Datenunsicherheiten explizit in die Analyse mit einbezogen werden. Zu diesem Zweck präsentiere ich vier Fallstudien mit einem Fokus auf zwei Zeiträume, das späte Holozän (die letzten zweitausend Jahre) und den Übergang von der letzten Kaltzeit zur aktuellen Warmzeit, die letzte glaziale Termination. Alle diese Studien legen einen räumlichen Fokus auf den Nordatlantik, eine Schlüsselregion globaler Klimavariabilität. Ich beschränke mich hierbei auf zwei Methoden, eine der netzwerkbasierten Zeitreihenanalyse, Sichtbarkeitsgraphen genannt, und eine der räumlichen Analyse, sogenannte Klimanetzwerke. Neben Erweiterungen von existierende Methoden, schlage ich auch neue Wege vor, um verlässliche Resultate auch für Zeitreihen mit hohen Unsicherheiten zu erhalten. Diese Fallstudien demonstrieren, dass Netzwerkmethoden auch für die Analyse von Paläoklima-Daten nützlich sein können. Sie sind daher ein weiterer Schritt hin zu einer künftigen Anwendung durch eine größere Anzahl an Forschenden. / In recent years, complex networks have become an increasingly popular tool to analyse relationships and structures in high-dimensional data sets in a variety of research fields. They have, however, rarely been applied to paleoclimate data sets, even though the growing number of published records demands efficient tools of multivariate analysis. The few published results that combine network methods and paleoclimate proxies are often not robust or have high uncertainty levels, linked tothe low dimensionality, resolution and the large uncertainties of most particulate time series. In this thesis, I propose several ways to overcome these issues in order to obtain reliable and quantitative results from network based tools by taking the particularities of paleoclimate data into account. For this purpose, I present four case studies, focusing on two time periods, the late Holocene (last two millennia) and the transition from the last ice age to the recent warm period, the last deglaciation. These studies are all related to the North Atlantic, a key region in multi-decadal to millennial scale climate variability. I primarily use two methods, one of network based time series analysis named visibility graphs and one of spatial analysis, so called limate networks. I have both further developed existing methods, but also propose new ways to yield reliable results when dealing with highly uncertain paleoclimate data. The case studies demonstrate the usefulness of network based data analysis to study patterns of regional climate variability. Hence, this work is another step in bringing network based approaches to a larger audience and towards a wider application of these methods.

The occupation of Western Sahara is a question of a forgotten colonization with a very limited framework of international recognition, media acknowledgment and talks. To break the remaining silence and invisibility, human rights activists have developed different initiatives, shedding light on the current situation of Western Sahara. This study investigates the Sahara Marathon campaign, an international sport event that has been developed in the Western Sahara refugee camps of Smara, El Aaiún and Auserd for twenty consecutive years.  Framing the Sahara Marathon as a case study, this degree project aims at inquiring into the potential impact and long-term implications of the international sport campaign, seeking “if” and “how” it contributes towards a social change and an end to the enforced invisibility of “Africa's last colony”, (Güell, 2015). In particular, this qualitative study examines the participatory approach and community engagement promoted through the campaign as well as the awareness-raising and dialogical processes triggered as a result of the Sahara Marathon sport event. The study is grounded on 23 in-depth interviews that have contributed to the external reliability of the research, underlining the reflections shared by organizers of the Sahara Marathon, drivers, freelancers, runners and most importantly human rights activists from Western Sahara. Findings reveal that the Sahara Marathon campaign raises awareness about the current situation in Western Sahara, contributing to a transnational acknowledgment of the conflict. The study also shows that active listening and convivial experiences are promoted throughout the campaign, dismantling stereotypes among communities coming from abroad and Saharawi people living in the refugee camps. In terms of participation, it has been concluded that the campaign uses a participation by consultation approach, needing a new model to showcase the utility and effectiveness of the event as well as to ensure its sustainability in the future.

Supply chains in many industries are experiencing an ever-growing complexity. They involve many actors and, similar to intra-organizational processes, visibility is an important enabler for managing supply chains in an inter-organizational setting. It is the backbone of advanced sup-ply chain (event) management solutions, which serve to detect critical incidents in time and to determine alternative actions. Due to the numerous parties involved, distributed supply chains call for a modular system architecture that aims at re-using visibility data from standardized sources. Following the wide variety of supply chain configurations in many industries there are also many options to design such services. This paper sheds light on these aspects by conduct-ing a case study on EPCIS, a global service specification for capturing and sharing visibility data. Based on three implementations, it shows the main design options for a supply chain vis-ibility service, generic operator models as well as major potentials.:1. Introduction and motivation 2. Research questions and methodology 3. Literature analysis 4. EPCIS case study 4.1. Deutsche Post DHL 4.2. ThyssenKrupp 4.3. GS1 Germany 5. Discussion and findinds 5.1.Design options 5.2. Operator models 5.3. Potentials 6. Conclusions

The use of past archaeological survey data for examination of landscape dynamics became very popular during the last decades of the 20th century, when Geographical Information Systems analysis were introduced in archaeology. In the present thesis, past survey data from Northern Messenia’s Middle and Late Helladic periods are combined to the topography and the environment of the region. These data are examined under the GIS prism, which attempts to update our knowledge on this geographical area.             The main scope of this thesis is to examine potential settlement patterns and land use, connectivity between sites and sites’ hierarchies. In the first query, the Kernel Density analysis has been used for estimating settlements’ patterns, and to consequently estimate preference of specific topographical features for land use, such as slope. Based on the patterns formed as a result of the analysis conducted in the first query, connectivity and hierarchy between sites is being tested with the use of cost connectivity and visibility tools.             The outcome of this analysis shows that the inhabitants of the past were significantly interacting with the landscape, since they preferred to nest around the protective slopes of the Soulima and the Kyparissian valleys. The area around their settlements reveals that these inhabitants opted to cultivate in flat or marginal land, while visibility from the sites seems to be an important factor for monitoring the region. However, it has been proved that a good number of collaborating sites were required to supervise the entire territory, which disproves any hierarchical ranking between them. On the other hand, connectivity depicts potential movement over Northern Messenia’s terrain and indicates that a few sites in the heart of the study area were to be considered as panoptic meeting grounds of the eastern and the western side. In conclusion, the overall analysis reveals a potential spatial bond between sites rather than a relationship based on rivalry.

Fluorkemi används på varselkläder i syfte för att skydda textilen mot smuts, vatten, fett och olja. Kemikalierna är skadliga för människor och miljö, de är dessutom mycket svårnedbrutna eller så bryts de inte ner överhuvudtaget. Kemikalierna är utvecklade av människor och delas upp i perfluorerade och polyfluorerade ämnen (PFAS). PFAS klassificeras också som PBT-ämnen, vilket står för att de är persistenta, bioackumulerande och toxiska. Studien är utförd i ett samarbete med Tranemo Textil AB, där behovet av fluorkarbonberedning på varselkläder undersökts. Syftet med studien är att undersöka utifrån användning och tvättprocess om fluorkarbonberedning är essentiell på varselkläder. Genom intervjuer med experter och tvätterier har studien fått fram information om fluorkemi och hur tvättprocessen ser ut. Resultatet från intervjuerna har kombinerats med tester på tyger och på ett bärprov med ett byxben med fluorkarbonberedning och ett byxben utan. Bärprovet har testats av en person i dennes dagliga arbete under sex månader. Studien har sammanställt resultatet och kan konstatera att fluorkemin har negativ påverkan på människa och miljö, vilket ligger till grund för en diskussion kring vad som är nödvändig användning. Vidare kan det konstateras att fluorkarbonberedningens effekt försämras över tid, genom användning, tvätt och annan yttre påverkan. Slitaget sker ojämnt och vissa delar av ett plagg kan ha god avvisande effekt medan andra delar är så kallade öppna friytor. Smuts kan då gå in under beredningen och kapslas in. I resultatet har det också framkommit att rätt skötsel av den här typen av plagg är viktigt och att återaktivering genom värme är väsentlig. Samtidigt belyser respondenterna återkommande en mentalitet hos arbetare att de vill att plaggen ska visa att de arbetar och därför vara smutsiga, vilket medför att många plagg sällan tvättas. Genom utförda intervjuer och tester har studien kommit till slutsatsen att fluorkemi inte är nödvändig på varselkläder. Den yttre påverkan som relativt snabb sliter på beredningen genom användning och tvätt i kombination med att fluorkemin inte fyller någon långvarig avvisande funktion är aspekter som tagits i hänsyn för slutsatsen. / Fluor chemistry is used on high visibility workwear to protect the textile from dirt, water, grease, and oil. The chemicals are harmful to people and the environment, they are also very degraded, or they do not break down at all. The chemicals are developed by humans and divided into perfluorinated and polyfluorinated substances (PFAS). PFAS is also classified as PBT substances, which means that they are persistent, bioaccumulate, and toxic. The study was in collaboration with Tranemo Textil AB, where the need for fluorocarbon finish for high visibility workwear was explored. The purpose of the study is to investigate if a fluorocarbon finish is essential on high visibility workwear, based on the use phase and washing process. Through interviews with experts and laundries, the study has obtained information about fluor chemistry and how the washing process works. The results of the interviews have been combined with tests on fabrics and on a wear test that has been tested in the person’s daily work for six months. The wear test is trousers with one leg with fluorocarbon finish and the other leg without. The study has compiled the results and can find that fluor chemistry has a negative impact on humans and the environment, which forms the basis for a discussion about what is essential use. Furthermore, it can be found that the effect of the fluorocarbon finish impairs over time, through use, washing, and other external impacts. The abrasion is uneven, and some parts of the garment can still have a good repellent effect, while other parts have so-called open surfaces. On the open surfaces, dirt can enter during the fluorocarbon finish and be encapsulated. The study has also emerged that proper care of this type of garment is important and that reactivation through heat is essential. At the same time, respondents repeatedly highlight workers' mentality that the garment should show and reflect high work ethics. This causes that many garments are rarely washed and become very dirty. Through interviews and tests, the study has concluded that fluor chemistry is not necessary for high visibility workwear. The external effects with relatively quickly abrasion on the finish through use and washing, this in combination with that fluor chemistry does not fulfil any long-lasting function are aspects that have been considered in the conclusion.