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The ability to quantify soil moisture spatial variability and its temporal dynamics over entire fields through direct soil observations using remote sensing will improve early detection of water stress before crop physiological or economic damage has occurred, and it will contribute to the identification of zones within a field in which soil water is depleted faster than in other zones of a field. The overarching objective of this research is to develop tools and methods for remotely estimating soil moisture variability in agricultural crop production. Index-based and machine learning methods were deployed for processing hyperspectral data collected from moisture-controlled samples. In the first of five studies described in this dissertation, the feasibility of using “low-cost” index-based multispectral reflectance sensing for remotely delineating soil moisture content from direct soil and crop residue measurements using down-sampled spectral data were determined. The relative reflectance from soil and wheat stalk residue were measured using visible and near-infrared spectrometers. The optimal pair of wavelengths was chosen using a script to create an index for estimating soil and wheat stalk residue moisture levels. Wavelengths were selected to maximize the slope of the linear index function (i.e., sensitivity to moisture) and either maximize the coefficient of determination (R2) or minimize the root mean squared error (RMSE) of the index. Results showed that wavelengths centered near 1300 nm and 1500 nm, within the range of 400 to 1700 nm, produced the best index for individual samples; however, this index worked poorly on estimating stalk residue moisture. In the second of five studies, 20 machine learning algorithms were applied to full spectral datasets for moisture prediction and comparing them to the index-based method from the previous objective. Cubic support vector machine (SVM) and ensemble bagged trees methods produced the highest composite prediction accuracies of 96% and 93% for silt-loam soil samples, and 86% and 93% for wheat stalk residue samples, respectively. Prediction accuracy using the index-based method was 86% for silt-loam soil and 30% for wheat stalk residue. In the third study, a spectral measurement platform capable of being deployed on a UAS was developed for future use in quantifying and delineating moisture zones within agricultural landscapes. A series of portable spectrometers covering ultraviolet (UV), visible (VIS), and near-infrared (NIR) wavelengths were instrumented using a Raspberry Pi embedded computer that was programmed to interface with the UAS autopilot for autonomous reflectance data acquisition. A similar ground-based system was developed to keep track of ambient light during reflectance target measurement. The systems were tested under varying ambient light conditions during the 2017 Great American Eclipse. In the fourth study, the data acquisition system from the third study was deployed for recognizing different targets in the grayscale range using machine learning methods and under ambient light conditions. In this study, a dynamic method was applied to update integration time on spectrometers to optimize sensitivity of the instruments. It was found that by adjusting the integration time on each spectrometer such that a maximum intensity across all wavelengths was reached, the targets could be recognized simply based on the reflectance measurements with no need of a separate ambient light measurement. Finally, in the fifth study, the same data acquisition system and variable integration time method were used for estimating soil moisture under ambient light condition. Among 22 machine learning algorithms, linear and quadratic discriminant analysis achieved the maximum prediction accuracy. A UAS-deployable hyperspectral data acquisition system containing three portable spectrometers and an embedded computer was developed to classify moisture content from spectral data. Partial least squares regression and machine learning algorithms were shown to be effective to generate predictive models for classifying soil moisture.

LiDAR is a remote sensing technology that uses a laser to map the surrounding environment. With its many applications, for example in autonomous vehicles, LiDAR is a growing field within technology and research. The silicon photomultiplier (SiPM) is a solid state device commonly used in the receiving system of a LiDAR. However, ambient light from sun or other light sources is also seen by the photodetector which creates noise in the receiving system. The purpose of this work is to examine how the performance of a 1D LiDAR with a SiPM receiver can be predicted, given a certain level of ambient light, target reflectance and measuring distance. This was carried through by working with mathematical models and comparing the outcomes to lab measurements of a certain LiDAR model. The outcome showed that describing the performance of the particular LiDAR by a model based on incident photon rate was difficult mainly due to the unknown relation between how the voltage signal threshold in the receiving electric circuit for when the LiDAR stops the time measurement relates to the number of microcells activated in the SiPM during a time span. However, the results obtained suggest a threshold value of between around 20 and 60 microcells activated within a 1 ns time interval, but further tests are needed in order to confirm or reject this. Of the two other approaches tried, the signal voltage model gave reasonable results for the values tested but in a rather indirect way. The other approach, describing the connection between DC noise and AC RMS noise in the receiving system gave results deviating between 40% and 320% from the lab results, i.e. not so good match. / LiDAR är en fjärranalysteknik som använder laser för att kartlägga ett geografiskt område. Med flertalet användningsområden, bland annat inom industrin för självstyrande fordon, är LiDAR ett växande teknik- och forskningsområde. Kisel-fotomultiplikatorn är en halvledarapparat som ofta används i LiDAR-mottagarsystemet. Bakgrundsljus från omgivningen detekteras dock också av fotodetektorn vilket orsakar  brus i mottagarsystemet. Detta arbete syftar till att testa metoder för hur prestandan hos en 1D LiDAR med en kisel-fotomultiplikator i mottagaren kan estimeras, i en viss nivå av bakgrundsljus, med en viss målreflektans på ett visst mätavstånd. Detta utfördes genom att arbeta med matematiska modeller och jämföra dess resultat med resultat från laborativa tester på en viss LiDAR-modell. Det visade sig vara svårt att beskriva prestandan för denna LiDAR enligt en modell baserad på fotonflöde, huvudsakligen på grund av den okända kopplingen mellan tröskelnivån i termer av voltsignal i mottagarkretsen då tidmätningen stoppas och antalet aktiverade mikroceller i kisel-fotomultiplikatorn under ett visst tidsintervall. De resultat som erhölls visar dock på en träskelnivå någonstans mellan 20 och 60 mikroceller inom ett 1 ns tidsintervall, men ytterligare tester bör genomföras för att konfirmera eller förkasta detta. Av de övriga två angreppssätten prövade, gav modellen baserad på voltsignal rimliga resultat för värdena testade men på ett relativt indirekt sätt. Försök till beskrivning av sambandet mellan DC brus och AC RMS brus i mottagarsystemet gav resultat med mellan 40% och 320% avvikelse från de laborativa mätningarna, relativt dåligt alltså.

Background: Neurocritical care requires rapid and accurate monitoring to prevent secondary brain injuries in patients with neurological diseases. Automatic pupillometry is a tool for assessing pupillary response (Neurological Pupil index). The role of nurses is central in monitoring and caring for the patient's neurological status to minimize secondary brain injuries and suffering.  Currently, it is unclear if ambient light can influence the Neurological Pupil index. Objective: The aim was to evaluate if the Neurological Pupil index is affected of ambient light during automatic pupillometry in unconscious or sedated intensive care patients. Method: A crossover design where pupillometry measurements were performed in bright and dark rooms at six time points on 20 intensive care patients. The results were analyzed using the Wilcoxon signed-rank test and presented with descriptive statistics. Results: Significant differences in the Neurological Pupil index were observed between dark and bright conditions. The majority of participants showed higher NPi in dark environments compared to light. There was individual variation in NPi measurements, with some participants showing larger differences than others. Conclusion: NPi is higher in dark environments compared to bright ones, and there are also individual differences. The results can guide clinical practice to improve the critical care nurse's assessment of neurological status in patients. Consistent lighting conditions during neurologic assessments of patients may potentially enhance the assessment of pupillary reactions and potentially enhanced nursing care for the patient.

Esta Tese é composta de projetos de intervenção realizados no período de 2004 a 2008. Os trabalhos de arte apresentados aqui são alterações na arquitetura de espaços de museus, galerias ou centros culturais. A natureza destes trabalhos é de uma resposta a estes contextos por meio de transformações operadas em sua luz ambiente. O uso de anteparos semi-transparentes que denomino filtros, cria um sistema temporário de dispositivos e efeitos que afetam o lugar e seus frequentadores. Esta tese aborda a qualidade mimética desta intervenções observando a estratégia comum a elas e também suas especificidades táticas. Os trabalhos são apresentados como \"máquinas de transformar\" que criam estados alterados do lugar. / This Thesis is constitued by intervention projects made from 2004 to 2008. The artworks presented here are alterations made in architectural spaces at museums, galleries, cultural centers, etc. The nature of these works is to respond to those contexts operating transformations in their ambient light. By using partially transparent surfaces that I define as filters, a temporary system of devices and effects is created to affect the place and its users. This thesis approaches the mimetic condition of these artworks, observing the strategy they have in common and also their tactical specificities. The artworks are presented as \"transformation machines\" that create altered states of the place.

Esta Tese é composta de projetos de intervenção realizados no período de 2004 a 2008. Os trabalhos de arte apresentados aqui são alterações na arquitetura de espaços de museus, galerias ou centros culturais. A natureza destes trabalhos é de uma resposta a estes contextos por meio de transformações operadas em sua luz ambiente. O uso de anteparos semi-transparentes que denomino filtros, cria um sistema temporário de dispositivos e efeitos que afetam o lugar e seus frequentadores. Esta tese aborda a qualidade mimética desta intervenções observando a estratégia comum a elas e também suas especificidades táticas. Os trabalhos são apresentados como \"máquinas de transformar\" que criam estados alterados do lugar. / This Thesis is constitued by intervention projects made from 2004 to 2008. The artworks presented here are alterations made in architectural spaces at museums, galleries, cultural centers, etc. The nature of these works is to respond to those contexts operating transformations in their ambient light. By using partially transparent surfaces that I define as filters, a temporary system of devices and effects is created to affect the place and its users. This thesis approaches the mimetic condition of these artworks, observing the strategy they have in common and also their tactical specificities. The artworks are presented as \"transformation machines\" that create altered states of the place.

The demand for automated home solutions is growing and it has created a market for automated blinds. For now most of these solutions seem to focus on fully opening and closing, either rolling blinds or slat blinds, with different electronic solutions. There doesn’t seem to be many solutions for continuously regulating light inlet based on ambient light. This project examined the possibilities of continuously regulating the amount of natural light let through a window. This was tested by measuring ambient light on one side of the blind with light dependant resistors (LDR’s) and regulating a Venetian blind based on measured light intensity. A feed-forward controller was implemented, programmed on an Arduino Uno board, to control sensors and actuators that regulate the blind. A prototype unit was built on a window-resembling wooden frame to evaluate the performance of the controller. The light sensitivity of LDR’s were sufficient for measuring differences in ambient light in different conditions where an automated blind could be used. The final prototype could be set to adjust light inlet in increments for changes in ambient light, thereby opening up to uses beyond simply closing and opening a light inlet. Future improvements could be to implement a feedback controller (e.g. a PID controller). The controller could be set to a certain reference as preferred ambient lighting in a room, thereby letting the controller adjust the blinds towards that reference value while conditions outside and inside change during the day. This could also be implemented in already existing smart home solutions. / Efterfrågan på automatiserade hemmalöningar är växande och det har skapat en marknad för automatiserade persienner. För nuvarande verkar det de flesta lösningarna fokusera på att helt öppna eller stänga, antingen rullgardiner eller persienner, med olika elektriska lösningar. Det verkar inte finnas många lösningar med kontinuerlig justering av inkommande omgivningsljus. Detta projekt utforskar möjligheterna för kontinuerlig justering av mängden naturligt ljus som släpps igenom ett fönster. Detta gjordes genom att mäta omgivande ljus på ena sidan av persiennen med fotoresistorer och reglera persiennen baserat på den uppmätta ljusintensiteten. Framkopplad styrning implementerades, programmerad på en Arduino Uno, för att styra sensorer och ställdon som reglerar persiennen. En prototypenhet byggdes på en fönsterliknande träram för att utvärdera prestandan av styrenheten.  Ljuskänsligheten i fotoresistorerna var tillräcklig för att mäta skillnader i omgivningsljus för de olika förhållanden där automatiserade persienner skulle kunna användas. Den slutgiltiga prototypen kunde ställas in att justera ljusinsläppet stegvis för skillnader i omgivningsljus, vari nya användningsområden öppnas upp utöver att endast stänga och öppna ett ljusinsläpp.  Framtida förbättringar skulle kunna vara att implementera en återkopplande styrning (t.ex. PID-styrning). Styrenheten skulle kunna ställas in till ett specifikt referensvärde på önskat omgivande ljus i ett rum, vari kontrollern justerar persiennerna för att hålla det önskade referensvärdet medan förhållanden utomhus och inomhus varierar under dagen. Detta skulle även kunna implementeras i redan befintliga smarta lösningar för hemmet.

Människan är utvecklad under dagsljusets dynamiska variation avfärgtemperatur, riktning och intensitet. Variationen påverkar våra känslor och prestation positivt. Problemet idag är att vi vistas ca 90% av dagen inomhus och att den artificiella belysningen inomhus oftasaknarvariation. Med varierande färgat ljus kan en ombytlig och stimulerande miljö skapas för att förbättra framtida belysningsmiljöer. Denna studie har undersökt hur brukarens motivation, välmående och koncentration påverkas av varierande färgad vertikalbelysning. En miljö som snabbt skulle bli enformig och understimulerande kan istället få en intressant variation som gör den brukbar en längre tid med denna belysningslösning, utan att motivationen eller välmåendet avtar. Belysningslösningen är ämnad att användas i perioder och fungera som en ”boost”. Experimentet var uppdelat i två behandlingar, en med arbetsbelysning utformad efter svensk belysningsstandard utan något vertikalljus och en där den färgskiftande vertikalbelysningen var adderad till arbetsbelysningen. Behandlingarna utfördes i en simulerad kontorsmiljö på Jönköpings Tekniska Högskola. Behandlingen med varierande färgad vertikalbelysningen skiftade långsamt i ljusfärger genom hela det synliga färgspektrumet på rummets vertikala ytor, detta för att skapa en variation i rummet. Under experimentets gång fick försökspersonerna besvara enkäter och genomföra koncentrationstest för att se hur det färgskiftande ljuset påverkade välbefinnandet och den kognitiva förmågan. Resultatet visade att det färgskiftande vertikalljuset hade positiv inverkan på motivation och välmående, effekten uteblev dock på koncentrationen hos försökspersonerna. Den positiva effekten som skedde var när ordningsföljden av behandlingarna började med det färgskiftande vertikalljuset adderat till arbetsbelysningen och avslutades med behandlingen som endast bestod avarbetsbelysningen. Slutsatsen är att varierande färgad vertikalbelysning kan öka motivationen och välmåendet om det appliceras på rätt sätt, utan att påverka koncentrationen negativt. Den simulerade kontorsmiljön saknade fönster, vid upp skalning av eventuell vidare forskning skulle en verklig kontorsmiljö med fönster vara att preferera. Att undersöka vidare om det är själva variationen av ljusets färger eller de enskilda färgerna på ljuset som skapar effekten hos brukarna ses också relevant, då denna studien inte behandlade det specifikt. / The human being has developed during the daylight's dynamic variation of color temperature, direction and intensity. The variation positively affects our emotions and performance. The problem today is that we stay about 90% of the day indoors and the indoor lighting often lacks variation. With dynamic colored light, a changeable and stimulating environment can be created to improve future lighting environments. This study has examined how the user's motivation, well-being and concentration are affected by dynamic colored vertical lighting. An environment that quickly would become dull and understimulating, can instead get an interesting variation that makes it usable for a longer time with this lighting solution, without the motivation or well-being decreasing. The lighting solution is intended to be used during time periods as a boost. The experiment was divided into two treatments, one with static office lighting designed according to Swedish lighting standard and one where the dynamic colored vertical lighting was added to the regular office lighting. The treatments were performed in a simulated office environment at Jönköpings Tekniska Högskola. The treatment with dynamic colored vertical lighting slowly shifted in light colors through out the whole visible color spectrum on the room's vertical surfaces, to create a variation in the room. During the experiment, the subjects were required to answer questionnaires and performance tests to measure the influence of the dynamic colored light on the subjects well-being and cognitive performance. The results showed that the dynamic colored vertical light had a positive effect on motivation and well-being, but did not affect the concentration of the subjects. The positive effect that occurred was when the order of the treatments started with the dynamic colored vertical light and then ended with the regular working light. The conclusion is that dynamic colored vertical lighting can increase the motivation and well-being if it is applied correctly, without adversely affecting the concentration. The simulated office environment lacked windows, when scaling up any further research, a real office environment with windows would be preferable. Investigating further whether it is the actual variation of the colored light or the individual colors of the light that creates the effect on the users is also relevant, as this study did not specifically process that.

Ljuset påverkar hur vi uppfattar och förstår vår omgivning. I en välplanerad ljusmiljö, där valav ljuskällor, placering av armaturer och fördelning av ljuset spelar in, känner vi oss trygga och kan utföra arbetsuppgifter på ett tillfredsställande sätt. Vertikala ytor som har en separat vertikalbelysning har stor påverkan på uppmärksamheten. Vertikalljus som uppstår från allmänljuset menar forskare inte har lika stor påverkan på uppmärksamheten som en separat vertikalbelysning. Detta examensarbete undersöker om föränderligt vertikalljus kan påverka trivsel och prestationen positivt i ett uppbyggt klassrum på Tekniska Högskolan i Jönköping. Syftet är att skapa en djupare förståelse för om ett föränderligt vertikalljus i formav ett vattenmönster påverkar människan. I undersökningen används två ljusscenarion; horistontell allmänbelysning bestående avpendlade armaturer med upp- och nedljus samt wallwashers enligt rekommendationer i Ljus & Rum. Andra scenariot består av samma nivå av allmänljuset med ett adderat föränderligt vertikalljus. För att besvara studiens frågeställningar användes en digital enkät med känsloskattningar och prestationstest. Resultatet av studien visar att majoriteten av deltagarna upplever att det föränderliga vertikalljuset bidrar till ökat fokus jämfört med enbart allmänljus. Resultatet visar att majoriteten av deltagarna har skattat ganska mycket intresserad vid båda ljusscenarion. Resultaten av prestationstesten visar att det är längre reaktionstid under förmiddagen oberoende ljusscenario. De slutsatser som dras i studien är att föränderligt vertikalljus bidrar till ökat fokus. Det går inte att avgöra ifall ett föränderligt vertikalljus bidrar till ökad pigghet, då flera faktorer spelar in. Resultatet visar att majoriteten av deltagarna upplever klassrummet som trivsamt när det föränderliga vertikalljuset är adderat till allmänljuset. Studien är för liten för att kunna dra slutsatser gällande samband mellan prestation och föränderligt vertikalljus. I vidare forskning hade ett större antal deltagare i enkätundersökningen varit intressant att studera. Vidare kan undersökningen pågå under en längre tidsperiod och vid olika årstider i en verklig miljö. Åldersspann, kön, koncentrationssvårigheter och nedsatt syn är några aspekter som kan redovisas i framtida studier. / The light affects how we perceive and understand our surroundings. In a well-planned lightenvironment, where choice of light sources, luminaire positioning and light distribution matters, we feel safe and can perform tasks in a satisfactory way. Vertical surfaces that have a separate vertical illumination gave a major impact on the attention. Vertical light appears from the general light means researches do not have as much influence on the attention as aseparate vertical light. This study research whether changing vertical light can affect wellbeing and performance positively in a structured classroom at the School of Engineering in Jönköping. The purpose is to create a deeper understanding of if a changeable vertical lightin a form of water pattern affects the human. The study uses two light scenarios; horizontal general light consisting of pendant luminaires with indirect and direct light as well as vertical lighting according to recommendations. The second scenario consists of the same level of general light with an added changeable vertical light. To answer the study's questions, a digital survey was used with emotional estimatesand performance tests. The result of the study shows that the majority of the participants experience that the changeable vertical light contributes to increased focus compared to general light only. The result shows that the majority of the participants have estimated quite interested in both light scenarios. The results of the performance test show that there is longer reaction time in the morning independent light scenario. The conclusions in the study are that changeable vertical light contribute to increased focus. It can not be determined whether a changeable vertical light contributes to increased alertness, as several factors are involved. The result shows that the majority of the participants experience the classroom as comfortable when the changeable vertical light is added to the general light. The study is too small to draw conclusions about the connection between performance and changeable vertical light. In further study, a bigger group of participants in the survey had been interesting to study. Furthermore, the survey can last for a longer period of time and at different seasons in a real environment. Age range, gender, concentration difficulties and vision loss are some aspects that can be presented in future studies.

With the wide spread of wireless technology, many devices, such as tablets, smartphones, notebooks, fixed and portable navigation systems are becoming immensely convenient to access and are making a significant contribution to our daily life. Compared to conventional PC, portable devices are used at different times of the day and in various conditions and environments, both indoors and outdoors. As a consequence, devices need to be adaptive and adaptable to a wide range of use contexts and conditions. It is often argued that contextual factors, such as the ambient illuminance in relation to characteristics of the display (e.g., surface treatment, size, screen reflectance, and display luminance) may have a strong influence on the use of such devices and corresponding user experiences. Yet, the current understanding of these influence factors is still rather limited. Therefore, in this thesis work, emphasis is given particularly to the impact of lighting on readability, visual performance and affective state. As a first step, a preparatory investigation focusing on the objective measure- ment of display luminance and contrast, display gloss, and luminance in different scenes, took place. For this first step, a large number of tablet and laptop dis- plays were evaluated. This preparatory investigation served as a complement to and as an input for step two, namely a subjective study with human test subjects which was organized in a controlled lab environment. In the subjective test (N=18), different types of displays, luminance settings and lighting conditions were included to investigate the impact on display read- ability. The results of subjective tests indicate that for matte, visual acuity and reading speed is both impaired by the increase of ambient light luminance. However, they are compensated effectively by the increase of display luminance when it is below 500-600 cd/ m2. Compared with matte display, the glossy dis- play shows to be more robust in relation to the ambient light, though it indeed has a negative effect on visual acuity and reading speed. However, for subjective feelings, there is no significant difference between the two displays. Both of them are influenced by the ambient light only. In the post-experiment evaluation of the preference of displays, the majority (61%) of the test subjects indicated a preference for the glossy display. / I och med spridningen av tradlos teknologi, blir enheter sasom surfplattor, smarta mobiler och GPS:er alltmer anvandbara och blir darmed en allt viktigare del av var vardag. Jamfort med en vanlig dator, anvands dessa barbara enheter i manga olika sammanhang i olika miljoer, bade inomhus och utomhus. Darfor maste de kunna anpassa sig till olika miljoer och forutsattningar. Det pastas ofta att omgivande faktorer sasom bakgrundsbelysning och hur dessa samverkar med skarmens egenskaper (yta, storlek, reflektans och ljusstyrka) kan han en viktig inverkan pa anvandningen av sadana enheter och motsvarande anvan- darupplevelse. Trots det ar var forstaelse av dessa faktorer fortfarande ratt begransad. Darfor fokuserar detta examensarbete specifikt pa hur lasbarhet, lasupplevelse och humor paverkas av ljusforhallandena. Som ett forsta steg, gjordes en forberedande studie med objektiva matningar av displayers ljusstyrka, kontrast och matthet i olika omgivningar. I detta forsta steg, utvarderades ett stort antal olika lasplattor och laptop-skarmar. Denna in- ledande undersokning bildade ett komplement och underlag till det andra steget, vilket var en subjektiv anvandbarhetsstudie med ett antal forsokspersoner, or- ganiserad i en reglerad labbmiljo. I anvandartesten (N=18), undersoktes lasbarheten for olika typer av dis- player under olika ljusstyrkeinstallningar och omgivande ljusforhallanden. Re- sultaten av anvandartesten indikerar att for matta displayer, paverkas skarpa och lashastighet negativt da den omgivande ljusstyrka okar. Detta kan dock effektivt kompenseras genom att oka displayens ljusstyrka, da den ar under 500-600 cd/m2. I jamforelse med matta displayer, visar sig blanka displayer vara mer robusta mot variationer i bakgrundsbelysningen. Daremot, for sub- jektiva kanslan, ar det ingen signifikant skillnad mellan de tva displaytyperna. I bada fallen ar det bara omgivande belysningen som paverkar. I en utvardering efter avslutat experiment, foredrog en majoritet (61%) av forsokspersonerna den blanka displayen.