Mehr als 90% eines Tages verbringen Europäer im Durchschnitt innerhalb von Gebäuden. In der Vergangenheit orientierten sich die Empfehlungen für Innenbeleuchtung überwiegend an den visuellen Anforderungen. Wenn man aber von einer evolutionären Anpassung des Menschen an natürliche Lichtbedingungen ausgeht, müsste sich die Nachbildung von natürlichen Lichtbedingungen, die über die visuellen Anforderungen hinausgehen, in der künstlichen Raumbeleuchtung positiv auf Befinden und Leistung auswirken. Diese Arbeit geht der Frage „Welche Eigenschaften des natürlichen Lichts sind wichtig und sollten bei der Innenbeleuchtung nachgebildet werden?“ auf den Grund und leistet mit neuen Erkenntnissen zur Lichtwirkung einen Beitrag zur Wissenschaft. Das zentrale Ziel dieser Arbeit ist die Beantwortung der Frage, ob sich eine technisch realisierte Lichtexposition, welche nach Qualität und Dynamik dem natürlichen Tageslicht ähnlicher ist als die heutige Standardbeleuchtung, positiv auf subjektive Befindlichkeiten und die Leistungsfähigkeit auswirkt. Ob und welche Dynamiken des natürlichen Lichts bei der Innenbeleuchtung nachgebildet werden sollten, um optimale Arbeitsbedingungen bei der Wissensarbeit zu schaffen, wird aus grundlegenden Untersuchungen zu dynamischem Licht abgeleitet. Schwerpunkt der Untersuchungen sind ultradiane Lichtwechsel.

<p>In perimeter building zones with glass façades, controllable fenestration (daylighting/shading) and electric lighting systems are used as comfort delivery systems under dynamic weather conditions, and their operation affects daylight provision, outside view, lighting energy use, as well as overall occupant satisfaction with the visual environment. A well-designed daylighting and lighting control should be able to achieve high level of satisfaction while minimizing lighting energy consumption. Existing daylighting control studies focus on minimizing energy use with general visual comfort constraints, when adaptive and personalized controls are needed in high performance office buildings. Therefore, reliable and efficient models and methods for learning occupants’ personalized visual preference or satisfaction are required, and the development of optimal daylighting controls requires integrated considerations of visual preference/satisfaction and energy use. </p> <p>In this Dissertation, a novel method is presented first for developing personalized visual satisfaction profiles in daylit offices using Bayesian inference. Unlike previous studies based on action data, a set of experiments with human subjects was designed and conducted to collect comparative visual preference data (by changing visual conditions) in private offices. A probit model structure was adopted to connect the comparative preference with a latent satisfaction utility model, assumed in the form of a parametrized Gaussian bell function. The distinct visual satisfaction models were then inferred using Bayesian approach with preference data. The posterior estimations of model parameters, and inferred satisfaction utility functions were investigated and compared, with results reflecting the different overall visual preference characteristics discovered for each person.</p> <p>Second, we present an online visual preference elicitation learning framework for efficiently learning and eliciting occupants’ visual preference profiles and hidden satisfaction utilities. Another set of experiments with human subjects was conducted to implement the proposed learning algorithm in order to validate the feasibility of the method. A combination of Thompson sampling and pure exploration (uncertainty learning) methods was used to balance exploration and exploitation when targeting the near-maximum area of utility during the learning process. Distinctive visual preference profiles of 13 subjects were learned under different weather conditions, demonstrating the feasibility of the learning framework. Entropy of the distribution of the most preferred visual condition is computed for each learned preference profile to quantify the certainty. Learning speed varies with subjects, but using a single variable model (vertical illuminance on the eye), most subjects could be learned to an acceptable certainty level within one day of stable weather, which shows the efficiency of the method (learning outcomes). </p> <p>Finally, a personalized shading control framework is developed to maximize occupant satisfaction while minimizing lighting energy use in daylit offices with roller shades. An integrated lighting-daylighting simulation model is used to predict lighting energy use while it also provides inputs for computing personalized visual preference profiles, previously developed using Bayesian inference from comparative preference data. The satisfaction utility and the predicted lighting energy use are then used to form an optimization framework. We demonstrate the results of: (i) a single objective formulation, where the satisfaction utility is simply used as a constraint to when minimizing lighting energy use and (ii) a multi-objective optimization scheme, where the satisfaction utility and predicted lighting energy use are formulated as parallel objectives. Unlike previous studies, we present a novel way to apply the MOO without assigning arbitrary weights to objectives: allowing occupants to be the final decision makers in real-time balancing between their personalized visual satisfaction and energy use considerations, within dynamic hidden optimal bounds – through a simple interface. </p> <p>In summary, we present the first method to incorporate personalized visual preferences in optimal daylighting control, with energy use considerations, without using generic occupant behavior models or discomfort-based assumptions.</p>

This study is a part of a poly generation project which will use animal waste or agricultural waste to produce biogas and will provide cooking gas, electricity and arsenic free clean water for drinking in rural areas of Bangladesh.  The study mainly analyzes the cooking and lighting energy demand of households across different income groups in a village named “Pani Para” in the Faridpur district in Bangladesh and also looks at the potential of biogas in the village. It has been done by adopting case study method and conducting a survey in the village using a questionnaire. Fuel mix across different income groups for meeting their cooking and lighting energy needs have also been studied along with socio-economic situation of the villagers and their preferences to change their current cooking fuel utilization patterns. Various scenarios like variation in fuel consumption patterns, priority of income expenditure and access to fuel with income level have been examined. The study also focuses to analyze the awareness of the villagers about biogas technology and their willingness to contribute for the poly generation project along with the willingness of households to pay for embracing change in current cooking and lighting fuels. Biomass potential i.e. cow dung and agricultural waste is also calculated in the surveyed village along with the production of biogas from the available biomass resources. The scenarios to provide the cooking gas, electricity and clean water through biogas poly generation project from the available resources are also investigated. Analysis reveals that the total energy consumption (cooking and lighting) increases with the increase in the income level among the households. Average household cooking and lighting energy demand by low, medium and high income groups is 8492 kWh/yr, 9789 kWh/yr and 14806 kWh/yr respectively. Cooking energy demand and agricultural waste consumption also show an increasing trend with the increase in land holding size. Among the income expenditure priorities food is one of the most important priorities and energy being less important due to availability of biomass at little or no cost. Awareness of biogas technology among the households and willingness to contribute for the poly generation plant shows an increasing trend with the increase in education level. The study shows that there is a positive response of the villagers for being willing to embrace the change in the current cooking patterns as well as welcoming new technologies that could support such a change. It was found that the cow dung resource in the village is not enough to produce sufficient biogas for the poly generation project. With the incorporation of the agricultural waste with the cow dung, biogas production comes quite close to requirement of the poly generation plant but however could not suffice it completely due to the lack of raw material in the studied village. In that case the scenario of providing electricity and clean water to all the villagers and providing all the three facilities to the 2/3rd of households is investigated. 1/3rd of the low income households then could meet their cooking demands by provision of improved cooking stoves as cooking gas could not be provided to them due to limited feedstock. The study shows that despite of the fact that cooking and lighting energy needs increase with income but there is not much variation in the fuel mix and almost everyone in the village rely on biomass to meet their energy demand. It is because there is very limited access to the modern fuel for cooking and no electricity access in the village, so the households have to rely on the traditional fuels. / <p>KTH School of Industrial Engineering and Management, Department of Energy Technology, Division of Energy and Climate studies</p>

Building Information Management and Digital Twin technology with help of Smart lights can optimizethe built environment impacting our health and well-being, by providing the right amount of light at theright time of day. Lighting simulation is challenging, due to the strict requirements to represent reality. Digitaltwin technology will provide a more dynamic two-way feed-back between the physical and the virtual environmentto optimize the lighting environment giving real-time sensor data. The main problem that currently occurswhile evaluating a lighting design made in photorealistic computer visualization is using the appropriate formof their model presentation. However, validation of light simulations has been done multiple times but not manystudies are based on DT-driven light environment evaluation in which not only the realistic representation butalso the exchange of information plays a crucial role. Therefore, the aim is to develop a strategy for demonstratingthe data exchange between a physical and real environment, for a scenario in which an optimal interactionbetween daylight and electric light derives an optimized realization of a given light demand curve. Basedon a quantitative experiment, validation of a Digital Twin was done between a virtual and a physical twin onan existing room using the light simulation tool DIALux evo. Data exchange was optimized for three levels ofgeometrical complexity. The light environment was optimized for interaction between the Digital and RealTwin. Counter to expectations, the results showed that the coarse model is more accurate representation of thephysical counterpart and generates faster data exchange. Defining DT usage purpose reduces time and effortdone on the process of creation. Knowing what data to exchange and how often avoid developers any limitationsor delaying in the process. Future studies can investigate how optimization of data exchange and light environmentcan be achieved with programming and parametric generative design.

Previous studies and research show that women feel unsafe to a greater extent than men do when staying outside during evenings and night time. To some women there is a fear of moving around in public areas which limits women’s freedom. Concerning feeling safe, lighting is regarded as the most important factor. In this study, investigations were conducted to get a greater knowledge about which lighting principle in and close to pedestrian underpasses that promotes safety the most. To answer the study’s research questions, a field study was conducted and a survey was made to be answered by people at the chosen underpasses. The field study consisted of three different pedestrian underpasses with three different lighting principles, which were all evaluated during different evenings. People who spontaneously passed by the underpasses were the subjects of the survey. A visual analysis of the lighting was made of the three lighting principles through a PERCIFAL analysis. A sketch analysis was also conducted in order to get a more visual understanding regarding space, close to and in the underpasses. Furthermore, to answer the study’s research questions an online survey was also conducted. The online survey contained photos of the three pedestrian underpasses and the three lighting principles that were previously discussed. In both surveys, questions regarding the subjects’ experiences of unsafety was asked. This contributed to statistics showing that the feeling of safety in, and close to underpasses varies between women and men. The result of the study show that women and men preferred the same type of lighting principle, a lighting principle with both light in and outside the underpass. The reason for why this lighting principle was the most preferred, was that there was a clear line of sight, as well as even distribution of light with low contrasts. The survey’s result show that women, in general, feel unsafe to a greater extent than men, which correlates to previous research. The study’s result show that whichever lighting principle there is, women feel more unsafe than men. If lighting principles are planned after what women consider safe, there is a chance that women can attain a higher sense of safety whilst being outside after dark. If these lighting principles are applied, the public space will become more equal since women hopefully can feel more safe and secure. For further studies, a combination between different methods are recommended to come up with a result. Preferably using both online surveys as well as field studies. Using an online survey as a method can contribute to a higher frequency of answers whilst field studies give the subject a chance to experience the atmosphere on location. However, field studies might lead to fewer answers. A field study can be conducted in the shape of an experimental investigation, where the lighting is planned with different lighting principles in order to later install the lighting principles where needed. Preferably, the experimental investigation should be conducted in one single underpass, in order to get the same conditions for all of the lighting principles. / Studier och forskning visar att kvinnor upplever otrygghet i högre grad än vad män gör när de vistas utomhus ensamma under kvälls- och nattetid. För en del kvinnor finns en rädsla för att förflytta sig i stadens rum vilket är en begränsning av kvinnans frihet. Ljus är den faktor som anses som viktigast för att kunna uppleva trygghet. I denna studie utfördes undersökningar för att få en förståelse för vilken belysningsprincip vid gångtunnlar som främjar trygghet. För att få svar på studiens frågeställningar utfördes en fältstudie där enkäter besvarades på plats. Fältstudien bestod av olika gångtunnlar med tre olika belysningsprinciper, som utvärderades var och en under olika kvällar. Försökspersoner som spontant passerade gångtunneln fick besvara enkäter. En visuell analys av ljuset gjordes för samtliga tre belysningsprinciper, genom en så kallas PERCIFAL-analys. Även skissanalyser gjordes för att få en ökad visuell förståelse kring den upplevda rumsligheten vid gångtunnlarna. Vidare för att besvara studiens frågeställningar utfördes även en undersökning i form av webbenkät. Webbenkäten bestod bland annat av foton på de tre olika gångtunnlar som tidigare behandlats i fältstudien. I båda enkäterna ställdes frågor angående enkätdeltagarnas erfarenhet av otrygghet, vilket sedan bidrog till statistik på hur trygghetsupplevelsen skiljer sig vid gångtunnlar mellan kvinnor och män. Resultatet från studien visade att kvinnor och män föredrog samma typ av belysningsprincip, en belysningsprincip med ljus både i och utanför gångtunneln. Anledningen till att den belysningsprincipen föredrogs var för att där fanns en tydlig siktsträcka samt ett jämnt ljus med låga kontraster. Enkäternas resultat visar att kvinnor känner sig mer otrygga i en högre grad än vad män gör, vilket stämmer överens med tidigare forskning. Studiens resultat visar att vilken belysningsprincip som än råder känner sig kvinnor generellt mer otrygga än vad män gör. Om belysningsprinciper planeras efter vad kvinnor anser som tryggt skapas en chans till att kvinnor kan uppnå en högre grad av trygghetskänsla under kvälls- och nattetid. Om dessa belysningsprinciper tillämpas kan det offentliga rummet bli mer jämställt eftersom kvinnors rörelsefrihet då förhoppningsvis kan öka. För vidare forskning rekommenderas en kombination av flera metoder för att få fram ett resultat, förslagsvis metoden webbenkät samt utföra fältstudie. Med webbenkät som metod kan svarsfrekvensen bli relativt hög. En fältstudie ger försökspersoner tillfälle att uppleva atmosfären på plats, men å andra sidan kan svarsfrekvensen bli låg. Fältstudie kan utföras i form av en experimentell undersökning, där ljuset planeras med olika belysningsprinciper, för att sedan installera de olika belysningsprinciperna på plats. Med fördel görs den experimentella undersökningen i en och samma gångtunnel för att då utgå från samma förutsättning under alla tester av olika belysningsprinciper.

Artificial Intelligence, being recently one of the most popular topics in technology, has been in a spotlight of Interaction Design for a long time. Despite its success in software and business-oriented cases, the adoption of Artificial Intelligence solutions in home environments still remains relatively low. This study reflects on the key reasons for the low penetration of AI-based solutions in private households and formulates design considerations for possible further developments in this area with a focus on artificial light sources. The design considerations are based on literature review and studies of multiple home environments gathered through qualitative interviews and context mapping exercises. Health influence of lighting, multi-user interactions, and privacy-related and ethical concerns are taken into account as the key factors. The considerations have been validated with participants of the study through user testing sessions of a digital prototype that virtualises a home environment and explores some of the common light usage scenarios. The study argues that despite multiple efforts in this direction during the past three decades, the future of Artificial Intelligence in connected, intelligent homes does not lie in smart, autonomous systems. Instead, Artificial Intelligence can be arguably used to simplify and contextualise interactions between humans and their home environments as well as foster the development of parametric solutions for private households.

Cette thèse visait à concevoir et à synthétiser des matériaux hybrides organiques-inorganiques à luminescence contrôlée et à les étudier en tant que luminophores pour l'éclairage à LED. L'objectif final était d'obtenir une source de lumière blanche. En effet, les LED blanches commerciales sont constituées d'un dispositif émetteur bleu recouvert d'un luminophore jaune. La combinaison de ces deux couleurs produit une lumière blanche. Cependant, cette lumière n'est pas de bonne qualité car il lui manque une composante rouge. Cela entraîne un mauvais rendu des couleurs des objets éclairés par ces sources de lumière. Dans notre travail, des polymères conjugués de différentes couleurs d'émission ont été obtenus avec succès. En particulier, plusieurs émetteurs de blanc ont pu être isolés.Dans cette thèse, non seulement les procédures de synthèse et les caractérisations chimiques sont présentées en détail, mais également les études des propriétés photophysiques des polymères, en solution et à l'état solide. Des études à l'état solide ont été effectuées sur les polymères et sur les polymères dispersés dans une matrice polymère. Ces études ont permis d'identifier les facteurs limitants quant aux utilisations pratiques de ces matériaux. Des solutions ont été proposées pour améliorer les performances d’émission et de stabilité des matériaux. De plus, ces travaux ont permis d'introduire la 2,2’-bipyrimidine comme nouvelle unité constitutrice pour le développement de polymères conjugués. / This thesis aimed at designing and synthesizing organic-inorganic hybrid materials with controlled luminescence and at investigating them as phosphors for LED lighting. The final goal was to obtain a white source of light. Indeed, commercial white LEDs are made up of a blue emitting device covered with a yellow phosphor. Combining these two colors yields white light. However, this light is not of good quality as it lacks some red component. This results in a bad rendering of the colors of objects illuminated by these sources of light. In our work, conjugated polymers with different emission colors have successfully been obtained. In particular, several single white emitters have been isolated.In this PhD thesis, not only the synthetic procedures and chemical characterizations are presented in detail, but also the studies of the photophysical properties of the polymers, either in solution or in the solid state. Solid state studies were performed on the bulk polymers and on the polymers dispersed into a polymeric matrix. These studies have lead to identify the limiting factors that could hamper the use of the materials. Solutions have been proposed to improve the materials performance and stability. Furthermore, 2,2’-bipyrimidine has been introduced as a new synthon for designing and developing conjugated polymers.

Indiana University-Purdue University Indianapolis (IUPUI) / Although current augmented, virtual, and mixed reality (AR/VR/MR) systems are facing advanced and immersive experience in the entertainment industry with countless media forms. Theses systems suffer a lack of correct direct and indirect illumination modeling where the virtual objects render with the same lighting condition as the real environment. Some systems are using baked GI, pre-recorded textures, and light probes that are mostly accomplished offline to compensate for precomputed real-time global illumination (GI). Thus, illumination information can be extracted from the physical scene for interactively rendering the virtual objects into the real world which produces a more realistic final scene in real-time. This work approaches the problem of visual coherence in AR by proposing a system that detects the real-world lighting conditions in dynamic scenes, then uses the extracted illumination information to render the objects added to the scene. The system covers several major components to achieve a more realistic augmented reality outcome. First, the detection of the incident light (direct illumination) from the physical scene with the use of computer vision techniques based on the topological structural analysis of 2D images using a live-feed 360-degree camera instrumented on an AR device that captures the entire radiance map. Also, the physics-based light polarization eliminates or reduces false-positive lights such as white surfaces, reflections, or glare which negatively affect the light detection process. Second, the simulation of the reflected light (indirect illumination) that bounce between the real-world surfaces to be rendered into the virtual objects and reflect their existence in the virtual world. Third, defining the shading characteristic/properties of the virtual object to depict the correct lighting assets with a suitable shadow casting. Fourth, the geometric properties of real-scene including plane detection, 3D surface reconstruction, and simple meshing are incorporated with the virtual scene for more realistic depth interactions between the real and virtual objects. These components are developed methods which assumed to be working simultaneously in real-time for photo-realistic AR. The system is tested with several lighting conditions to evaluate the accuracy of the results based on the error incurred between the real/virtual objects casting shadow and interactions. For system efficiency, the rendering time is compared with previous works and research. Further evaluation of human perception is conducted through a user study. The overall performance of the system is investigated to reduce the cost to a minimum.

Ljusföroreningar är ett stort framväxande problem och då fladdermöss oftast är nattaktiva erfaras de ingå i den taxa som påverkas mest. LED-belysning blir allt vanligare i gatubelysning och utstrålar bland annat inget UV-ljus jämfört med traditionella ljuskällor som utstrålar UV-ljus och därmed förändrar insekters- och potentiellt fladdermössens beteende. Det var därför relevant att undersöka hur den stod sig till traditionella ljuskällor med avseende på ekologisk påverkan. Med anledning av ett stort utbyte till LED i Karlstads kommun 2019 gavs en möjlighet att jämföra påverkan på fladdermöss utifrån olika ljuskällor. Syftet med studien var att undersöka om bytet till LED från traditionella ljuskällor skulle kunna ha en lägre påverkan på fladdermöss i Karlstads kommun och ifall en skillnad mellan arter kunde påvisas. Studien grundade sig i observationsdata hämtad från Fyndkartor via Artportalen, kartskikt från modelleringsverktyget PREBAT och kommunens belysningslager. Vidare har hänsyn tagits till födotillgång, avståndet till- och antalet boplatser, utifrån uppskattningar av PREBAT. Studien fann en signifikant medelskillnad om ca. 20% lägre avstånd till belysning mellan åren före och efter bytet till LED-belysning. Samtliga arter av fladdermöss hade lägre avstånd till LED-belysning jämfört med övrig belysning, däremot var skillnaden inte signifikant. Ingen signifikant skillnad kunde påvisas mellan arter, även om de mer opportunistiska arterna hade lägre avstånd till samtliga ljuskällor. Vidare kunde inte boplatsernas avstånd eller antal förklaras som en bidragande faktor till det låga avståndet till LED då fladdermössen inte visade en statistiskt signifikant ”preferens” för LED-belysning. Denna studie överensstämmer med tidigare forskning som säger att artificiell belysning påverkar fladdermöss men huruvida LED-belysning skulle ha en mindre ekologisk påverkan på fladdermöss är ännu inte klarlagt. Däremot finns det många åtgärder som kan sättas in för att reducera den ekologiska påverkan som ljusföroreningar har på fladdermöss och andra nattaktiva djur. / Light pollution is a rapidly growing problem and since bats often are nocturnal, they appear to be one of the taxa that is most affected. LED-lighting is becoming more common in street lighting, and it emits less UV light than traditional mercury lights, altering insect and potentially bat behavior. Thus, it is relevant to investigate LED-lighting compared to traditional light sources, in terms of the ecological impact. Owing to a large-scale switch to LED-lighting in Karlstad Municipality in 2019, there was an opportunity to compare the impact of different light sources on bats. The purpose of this study was to investigate if the switch to LEDs from traditional light sources could have a lower impact on bats in Karlstad, and to test if there were differences among species. The data in this study was based on observations from “Fyndkartor” at “Artportalen”, map layers from the PREBAT modeling software, and a map layer of the municipality’s street lighting. Consideration has been given to food supply, the distance to- and the amount of roosting sites, as estimated by the PREBAT model. The study found a significant mean difference of ca. 20% less distance to lighting between years before and after LED light installation. Each one of the four bat species had a lower distance to LED-lighting, compared to traditional lighting, but these differences were not significant. No significant difference was found among species, even though the more opportunistic species had a lower distance to each one of the light sources, as has been found in other studies. Furthermore, the distance to, or amount of, roosting sites could not explain why bats had a lower distance to LED-lighting, since the bats did not show a “preference” to LED that was statistically significant. This study is in line with previous research that confirms that artificial lighting has an impact on bats, but whether LED-lighting has a lower impact than other light sources still remains unclear. There are, however, many measures to be taken to reduce the ecological impacts that light pollution has on bats and other nocturnal animals.

In recent years there has been an increase in the number of apartments in Sweden. The officials are estimating that approximately 1000 primary schools need to be built to meet the 20% increase in students. Facing the rising demand; my thesis makes a contribution to sustainable school design via optimisation of the building orientation.This study utilises Rhinoceros with Grasshopper visual programming language alongside Ladybug, Honeybee and Owl scripts, as well as Climate Studio plugin. The environmental performance analysis software’s results include horizontal and vertical illuminance, Daylight Factor, as well as melanopic Equivalent Daylight (D65) Illuminance. Those findings are further supported with on-site measurements and observations in Iggesund school.