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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Evaluation of acoustic, visual and thermal comfort perception of students in the Educational Building at KTH Campus : A study case in a university building in Stockholm

Kritikou, Sofia Kristina January 2018 (has links)
In recent years the focus and application of sustainability in buildings has risen. Both for environmental and human well-being reasons. The quality of the indoor environment affects the well-being, productivity and work performance, but it can also affect the occupants negatively, like increasing risks of different diseases and health issues. A good indoor environment alongside with sustainable materials, proper HVAC (Heating, ventilation, and air conditioning) installations and building code regulations contribute to a sustainable solution with low environmental impact and reduced energy consumption. Since buildings alone are responsible for 38% of all human GHG (Greenhouse gas) emissions (Wikipedia, 2017), most countries recommend new more sustainable solutions to reduce that percentage. For example, in the EU, the 2020 climate and energy package targets to: cut 20% in greenhouse gas emissions, 20% of EU energy from renewables and 20% improvement in energy efficiency (European Comission, n.d.). In addition to the positive aspect of low environmental impact new constructions have, they also create a good living or working environment for the users. Studies have shown that a better indoor quality increases the productivity and work performance, but most of all the occupants feel comfortable and satisfied with their environment. A great number of papers have reviewed the acoustic, visual, thermal comfort and indoor air quality, which are main aspects of the indoor climate. Most papers focus on the users’ perception of these four aspects as well as other parameters that influence the indoor environment (architectural geometry, materials, etc.). Similarly, in this study case I focus on two different methods of obtaining the results, the objective method that contains the indoor environment measurements and the subjective method which includes a questionnaire created specifically for this research project. By obtaining these two sets of data, key focus points are developed, such as if the building’s certification meets the recommendations of Miljöbyggnad, what aspects influence the students’ perception the most, and whether there are any distinct connections between measured and calculated data. This study case was developed in a university building in Stockholm, where the four main aspects of the indoor environment were evaluated. The physical parameters such as temperature, air velocity, relative humidity, CO2 concentration and acoustics were measured in five different classrooms. In addition, a survey was developed for this study which included perception questions of the thermal, visual, acoustic comfort and indoor air quality. As found in other studies, gender and climate zone origin affected the overall indoor environmental perception. Even though the majority of both genders voted for “no change”, the remaining females answered that they preferred the conditions warmer. Also, the majority of answers from all climate zones were “no change”. However, the second highest opinion for students from warmer climate zones was “warmer”, which has also been found in other studies. Significant negative correlations were found between the acoustics and the satisfaction level of the acoustic comfort. Similarly, high correlations were observed between the visual comfort satisfaction level and the three aspects influencing it. Furthermore, the results showed that all physical measurements influenced the students’ thermal comfort and indoor air quality perception. All measurements obtained indicated a good indoor environment in all classrooms, and all values were between the Swedish Standards recommendations. Low correlation was found between the measured PVM and the AMV from the questionnaires even though all the values were among the limitations. Lastly, this study reviews methods that could be applied to similar future studies and, discusses what kind of errors to avoid in the future. There is still a lot of research that can be developed in order to gain a deeper understanding of the indoor environment and how humans perceive it. / Under senare år har fokus och tillämpning av hållbarhet i byggnader ökat, både för miljö och mänskligt välbefinnande. Kvaliteten på inomhusmiljön påverkar välbefinnandet, produktiviteten och arbetsprestandan. Tyvärr kan det också påverka de anställda negativt, som ökad risk för olika sjukdomar och hälsoproblem. En bra inomhusmiljö tillsammans med applikationer av hållbara material, ordentliga HVAC-installationer och byggregler bidrar till en hållbar lösning med låg miljöpåverkan och minskad energiförbrukning. Eftersom byggnader ensamma svarar för 38% av alla mänskliga växthusgasutsläpp (Wikipedia, 2017), rekommenderar de flesta länder nya mer hållbara lösningar för att minska den procentuella andelen. I EU strävar EUs klimat- och energipaket 2020 till att; minska 20% av växthusgasutsläppen, 20% av EUs energi från förnybara energikällor och 20% förbättrad energieffektivitet (European Commission, n.d.). Förutom den positiva aspekten av låg miljöpåverkan har nya konstruktioner skapat en bra levnads- och arbetsmiljö för användarna. Studier har visat att en bättre inomhuskvalitet ökar produktiviteten och arbetsprestandan men framförallt känner sig brukarna bekväma och nöjda med sin miljö. Ett stort antal rapporter har granskats enligt akustisk, visuell, termisk komfort och inomhusluftkvalitet, som är huvudaspekterna av inomhusklimatet. De flesta rapporter fokuserar på användarnas uppfattning om dessa fyra aspekter samt andra parametrar som påverkar inomhusmiljön (arkitektonisk geometri, material osv.). På samma sätt fokuserar jag på två olika metoder för att erhålla resultaten. Den objektiva metoden som innehåller innemiljömätningar och den subjektiva metoden som innehåller ett frågeformulär som skapats specifikt för detta forskningsprojekt. Genom att erhålla dessa två uppsättningar data utvecklas viktiga fokuspunkter, till exempel om byggnadens certifiering uppfyller Miljöbyggnads rekommendationer, vilka aspekter som i huvudsak påverkar elevernas uppfattning och om det finns några tydliga samband mellan uppmätta och beräknade data. Studiefallet utvecklades i en universitetsbyggnad i Stockholm, där de fyra huvudaspekterna av inomhusmiljön utvärderades. De fysiska parametrarna mättes såsom temperatur, lufthastighet, relativ fuktighet, CO2-koncentration och akustiken i fem olika klassrum. Dessutom har en undersökning utvecklats för detta studieprojekt som inkluderade uppfattningsfrågor inom termisk, visuell, akustisk komfort och inomhusluftkvalitet. Kön och klimatzonens ursprung var två andra parametrar som påverkade den övergripande inomhusmiljöuppfattningen, enligt andra studier. Även om majoriteten av båda könen röstade för "ingen förändring" svarade restrerande kvinnor att de föredrog klasrummet varmare. Dessutom svarade flertalet från alla klimatzoner "ingen förändring", även om den näst högsta åsikten för studenter från varmare klimatzoner var "varmare", vilket också har hittats i andra studier. Höga negativa korrelationer hittades mellan akustiken och tillfredsställningsnivån för den akustiska komforten. På samma sätt observerades höga korrelationer mellan den visuella komfortnöjdhetsnivån och de tre aspekter som påverkar den. Vidare visade resultaten att alla fysiska mätningar påverkade elevernas termiska komfort och upplevelse av inomhusluftkvalitet. Alla erhållna mätningar indikerade en bra inomhusmiljö i alla klassrum och att alla värden var inom svensk standards rekommendationer. Låg korrelation hittades mellan den uppmätta PVM (predicted mean vote) och AMV (actual mean vote) från frågeformulären även om alla värden var inom gränserna. Dessutom granskar studien metoder som kan tillämpas på liknande framtida studier liksom vilka slags fel som bör undvikas i framtiden. Det finns fortfarande mycket forskning som kan utvecklas för att förstå mer om inomhusmiljön och hur människor uppfattar den.
22

Contribution à l’étude du confort visuel en lumière naturelle dans les établissements scolaires en Libye : évaluation qualitative et préconisations / Contribution to the study of visual comfort of natural light in Libyan schools : qualitative evaluation and recommendations

Abdelatia, Belal 01 October 2013 (has links)
La recherche propose de faire la démonstration qu’il existe une certaine relation de cause à effet entre la prise en compte des paramètres du confort visuel dans la conception des établissements scolaires et la performance scolaire des utilisateurs. Dans ce sens, nous essaierons de montrer comment la façon dont l’éclairage naturel sera introduit dans une salle de classe sera un facteur déterminant du confort visuel. En termes de méthodologie, nous avons retenu une approche qualitative qui permet de répondre, de manière simple et efficace, aux objectifs de cette recherche. Dans un premier temps, nous établissons un état de l'art du concept de l’éclairage naturel et du confort visuel en milieu scolaire. Ensuite, nous proposons une méthode d'analyse et d'évaluation qui s’articule autour de deux phases : - l’une consiste à analyser la qualité environnementale des établissements scolaires en Libye. L'objectif de cette phase est d’arriver à une classification typologique des salles de classe existantes dans notre zone d’étude ;- l’autre consiste à incorporer des simulations par maquette, qui nous permettent la collection des informations maximales dans le temps le plus court, par une série de photos enregistrant les conditions de confort visuel. Cela nous permet de montrer de façon simplifiée l’impact des caractéristiques des salles de classe étudiées, notamment leurs orientations, qui peuvent avoir une influence directe ou indirecte, positive ou négative, sur le confort visuel et par extension sur la performance scolaire de ces utilisateurs.D'après les résultats obtenus, nous avons constaté que les établissements scolaires en Libye, tels qu’ils sont conçus et réalisés actuellement, ne répondent guère aux besoins de leurs utilisateurs et ont sur eux un impact considérablement négatif. Enfin, à la lumière de l'ensemble des constatations, nous discutons les conséquences de nos résultats obtenus pour la conception architecturale des futurs établissements scolaires en Libye, et nous proposons ensuite d’établir une liste des recommandations appropriées au contexte climatique de la zone d'étude pour la conception des salles de classe, afin de les mettre à la disposition des architectes et des autorités pour d’éventuelles utilisations et approfondissements, qui permettent non seulement de rénover des édifices existants mais aussi d’améliorer la conception des futures constructions. / The research deals with demonstrating that there is some cause-and-effect relationship between the inclusion of visual comfort parameters in the design of schools and academic performance of the users. We try to show how the way natural light is introduced into a classroom will be a determinant of visual comfort.In terms of methodology, we used a qualitative approach which allows identifying, quickly and easily, the context of this research. At first, we establish a state of the art of the concept of day lighting and visual comfort in schools. Then, we propose a method of analysis and evaluation based on two phases:- One is to analyze the environmental quality of schools in Libya. The objective of this phase is to arrive at a typology of existing classrooms in our study area;- The other is to incorporate model simulations, which allow us to obtain the maximum information in the shortest possible time, by a series of photographs recording the conditions of visual comfort. This allows us to understand, in a simple way, the impact of the studied classroom characteristics, including their orientations, which may have a direct or indirect influence, positive or negative, on visual comfort and by extension on the academic performance of the users.According to the results, we found that the Libyan schools, as they are currently designed and implemented, do little to address the needs of their users and have a considerable negative impact on them.Finally, in the light of all these findings, we discuss the implications of our results for the architectural design of future schools in Libya. We then propose to establish a list of recommendations appropriate to the climatic context of the study area for the design of classrooms in order to make them available to architects and authorities for possible uses and further investigations. This allows not only to renovate the existing buildings but also to improve the design of future buildings.
23

Digitala skyltar i stadsmiljö : Utvärdering av ljusemitterande storbildsskärmars kontrastförhållande och påverkan på det upplevda stadsrummet / Digital signages in urban environments

Martinsson, Viktor, Wikström, Tina January 2017 (has links)
Denna studie syftar till att förse kommuner och fackmän med en rimlig utgångspunkt vid upprättande av ljusemitterande skyltar i stadsmiljö och på så vis bidra till perceptuellt väl sammansatta stadsrum. De vägledande frågeställningar som tas upp i rapporten ser till såväl lämpliga kontrastförhållanden som digitala skyltars påverkan på rumsupplevelsen. Med grund i vetenskapsteori rörande seende, rumslig upplevelse och digitala skyltar upprättades en 20 kvadratmeter stor digital skylt på Tändstickstorget i Jönköping, vari ett fältexperiment kom att äga rum den 15 mars 2017. Under experimentet kom skylten att ställas till sex olika scenarier med avseende på skyltluminans och kontrastförhållande till dess direkta omgivning, vilka samtliga granskades av en respondentgrupp om 20 personer. Därefter följde en omfattande visuell utvärdering av den digitala skyltens perceptuella påverkan på det aktuella torgrummet, med skylten inställd på det scenario som dömts behagligast. Av resultaten framgår att ett lågt kontrastförhållande mellan den ljusemitterande skylten och dess direkta omgivning föredras framför ett högt, då en tydlig korrelation mellan höga kontraster och obehag identifierats. Vidare visar resultaten att en digital skylt leder till att stadsrummet som helhet upplevs mörkare och att dess upplevda form och storlek förändras. Konkurrens uppstår mellan lokala landmärken och skylten, då dess luminanta yta blir det dominerande objektet i synfältet. Det framgår tydligt av undersökningen att beslut vid implementering av digitala skyltar i stadsmiljö bör styrkas med en god kunskapsgrund, något som resultaten och det specifikt för studien utformade mätdataformuläret avser bidra till. / This thesis aims to provide municipalities and professionals with a reasonable starting point when planning for light emitting signs in urban environments, thus contributing to perceptually cohesive urban spaces. The questions raised in this report examine appropriate contrast ratios as well as digital signage’s impact on the spatial experience. Based on scientific theory concerning human vision, spatial experience and digital signage’s a 20-square meter digital sign was installed at Tändstickstorget in Jönköping, where a field experiment took place on the 15th of March 2017. The sign was programmed into six different scenarios with regard to its screen luminance and contrast ratio to its immediate surroundings, all of which were reviewed by 20 respondents. Furthermore, an extensive visual evaluation was carried out to investigate the perceptual impact the digital sign had on the city square, with the sign set to the scenario deemed most pleasant. The results show that a low contrast ratio between the light emitting sign and its immediate surroundings is preferred to a high ratio, seeing as a clear correlation between high contrasts and discomfort has been identified. Moreover, the results show that a digital sign makes the urban space perceptually darker overall, whilst at the same time affecting the form and size of the space. Competition arises between the local landmarks and the sign, as its luminous surface becomes the dominant object in the field of view. It is clear from the study that decisions regarding the implementation of digital signs in urban environments should be strengthened with a good knowledgebase, which the results along with the measurement data form developed specifically for the study intends to contribute with.
24

Análise do desempenho luminoso através de uma janela em sacada : estudo comparativo para os climas de Maceió, Brasil e Valparaíso, Chile.

Kähni, Amaya Glaría 23 April 2010 (has links)
This present dissertation focuses on the study of the daylight performance produced by the use of Bow Window in the residential sector. The system Bow Window is a simply designed window facing outward from the façade. Moreover this architectural element is influenced by a multitude of cultural trends and imported from various parts of the world. Nowadays in Chile the use of such windows has been largely used, regardless of the climatic aspects. Similarly, in Brazil, these architectural elements been used in the same way. The investigation has considered the Bow Window as a space in between more likely as a intermedium space, therefore the focus of this research project is to contribute to the daylight performance of the above named spaces. The methodology used involves the comparative study between Bow Window and simple window in dwellings in two cities; Maceió, Brazil and Valparaíso, Chile. In addition to this, the methodology includes the analysis of vertical and horizontal solar protection.The study was carried out using software as the main tool TropLux. The base case was a room model including Bow Window in its configuration. From the results can be concluded that the Bow Window contribute to the daylight uniformity within the model, due it can decrease the high iluminance in the closest areas near to the studied window when compared with a standard window. Furthermore, the horizontal and vertical sun protections applied to Bow Window have shown to be useful to decrease the high daylight levels, particularly in the areas with higher solar radiation according to the Bow Window orientation and hourly transition. / Fundação de Amparo a Pesquisa do Estado de Alagoas / A presente pesquisa estuda a influência luminosa produzida no uso da Janela em Sacada em habitações. A "Janela em Sacada" é um tipo de janela saliente da fachada, de desenho sensível à influência dos movimentos culturais. Este espaço de vidro foi importado pelos diversos lugares no mundo. Na atualidade, no caso de Chile, seu uso tem sido intenso e indiscriminado, produzindo um elemento arquitetônico que desconsidera os aspectos climáticos. No entanto, no caso de Brasil, também vêm sendo utilizadas algumas configurações similares destes espaços de transição. O objetivo principal deste trabalho é contribuir para o estudo dos espaços de transição, por meio da análise do desempenho luminoso da Janela em Sacada . A metodologia utilizada consiste em um estudo comparativo do desempenho luminoso entre uma Janela em Sacada e janelas simples, para as cidades de Maceió, Brasil e Valparaíso, Chile; incluindo a utilização de protetores solares verticais e horizontais. As simulações realizam-se por meio de simulação computacional através do software TropLux, utilizando-se um modelo padrão de sala que inclui a Janela em Sacada em sua configuração. Dos resultados e análise, pode-se concluir que a Janela em Sacada contribui com um maior ganho da iluminação nos ambientes, esta janela diminui o desempenho luminoso comparado com uma janela simples, até um 18%, principalmente na área perto da abertura, o que poderia contribuir com uma maior uniformidade luminosa na sala. Em relação a uma janela simples com beiral, a Janela em Sacada aumentará os níveis de iluminâncias, em até um 13%; contribuição gerada pela influência do plano inferior desta janela, que atua como elemento refletor. E, o uso de protetores solares na configuração desta janela, ajuda a diminuir, em até 50%, os altos níveis de iluminação das áreas com maior radiação, segundo a orientação e hora do dia.
25

Visual comfort in nursing rooms, from a patient’s perspective / Visuell komfort i vårdrum, ur patientens perspektiv

Palm, Adam, Kokko, Veera January 2018 (has links)
The awareness regarding important aspects of how to plan and design healthcare environments is something that is constantly progressing. Even though these environments can be seen as complex, the knowledge and understanding of its many different users is often taken into consideration in today’s planning. Several studies have shown positive effects on the visual performance among the hospital staff but also positive effects regarding visual comfort that facilitates recovery and well-being among patients. However, when planning lighting in healthcare environments today, the focus often lies on providing good lighting qualities regarding the visual performance of the hospital staff and the patients are, by that, not taken in consideration to the same level of extent. Therefore this study was focused on analyzing if certain demands could be set on lighting in a nursing room, to improve the experience of visual comfort, from a patient perspective, while using two different lighting scenarios. The thesis has been conducted using an already approved and widely used method Evidence based design (EBD) through a literature study, a pre-study, and an experiment. This to evaluate and develop an innovative design to facilitate visual comfort from a patient's perspective. The visual parameters that the experiment has been focusing on are glare, luminance, contrasts, shadows, lighting principles, and the perception of objects. These parameters have been evaluated from a sitting, standing and lying position in two different lighting scenarios, developed from the hypothesis, without access to daylight. A healthcare environment has a number of different users, that all use the facilities in different ways. Therefore it was important that the innovative design, constructed for the experiment, did not compromise the visual comfort or need of light for the other users. A questionnaire was created, based on the visual parameters, to help answer the research questions. The experiment had a total of 30 participants, where each participant answered the questionnaire six times, one for each position and a total of three times in each lighting scenario.   The results were compiled and the mean values were analyzed to evaluate differences and similarities between the two lighting scenarios and between the positions. The results of the experiment show that there are certain demands that can be set on the artificial lighting in a nursing room, and it also shows that it is of great importance to plan for a various lighting environment since it can enhance the experience of visual comfort. Despite this, it is important for a lighting designer to carefully analyze and evaluate the patient's need for light in the specific ward that is being designed. To achieve a sustainable lighting solution it is important to remember that all the sustainability factors, such as the social, economic and environmental factors, are equally important to create a sustainable development. / Medvetenheten gällande viktiga aspekter av hur man planerar och utformar vårdmiljöer är något som ständigt ökar. Trots att dessa miljöer kan ses som komplexa, tas ofta kunskap och förståelse i beaktning för miljöernas många olika användare vid dagens planering. Flera studier har visat positiva effekter på visuell prestanda hos sjukhuspersonalen, men även positiva effekter gällande visuell komfort som påskyndar återhämtning och ökar välbefinnande bland patienter. När belysningsplanering idag utförs i vårdmiljöer ligger fokuset ofta på att tillgodose ljuskvaliteter med avseende för sjukhuspersonalens visuella prestanda och patienterna beaktas därmed inte i samma omfattning. Därför har denna studie fokuserats på att analysera om vissa krav kan ställas på artificiell belysning i ett vårdrum, för att förbättra upplevelsen av visuell komfort utifrån en patients perspektiv, vid utvärdering  av två olika belysningsscenarion. Studien har genomförts med hjälp av en redan beprövad och allmänt använd metod Evidensbaserad design (EBD), genom en litteraturstudie, en förstudie och ett experiment. Detta för att utvärdera och utveckla en innovativ design med fokus på att underlätta visuell komfort från patientens perspektiv. De visuella parametrar som experimentet har fokuserat på är bländning, luminans, kontraster, skuggor, olika belysningsprinciper samt uppfattningen av objekt. Dessa parametrar har utvärderats från en sittande, stående och liggande position, vid två olika belysningsscenarion med enbart artificiell belysning, utvecklad utifrån hypotesen. I en vårdmiljö vistas ett antal olika användare som alla använder anläggningarna på olika sätt. Det ansågs därför viktigt att den innovativa designen, som konstruerats för experimentet, inte påverkade den visuella komfort eller behovet av ljus för övriga användare. Ett frågeformulär skapades, baserat på de visuella parametrarna, för att besvara frågeställningen. Experimentet hade totalt 30 deltagare, där varje deltagare besvarade frågeformuläret sex gånger, ett formulär per position och totalt tre gånger vid varje ljusscenario. Resultaten sammanställdes och medelvärden analyserades för att utvärdera skillnader och likheter mellan de två belysningsscenarierna samt mellan positionerna. Resultaten av experimentet visar att det finns särskilda krav att ställa på den artificiella belysningen i ett vårdrum. Resultatet visar även att det är av stor betydelse att planera in en varierad ljusmiljö då det kan förbättra upplevelsen av den visuella komforten. Utöver detta är det även viktigt för en ljusdesigner att noggrant analysera och utvärdera patientens behov av ljuset i den specifika avdelningen som utformas. För att uppnå en hållbar belysningslösning är det viktigt att ha i åtanke att alla hållbarhetsfaktorer, såsom de sociala, ekonomiska och ekologiska, är lika viktiga att ta hänsyn till för att skapa en hållbar utveckling.
26

Segurança, eficiência energética e conforto visual em emboques de túneis rodoviários: soluções arquitetônicas / Safety, power efficiency and visual comfort at the access zone of highway tunnels: architectural solutions

Moura, Norberto Corrêa da Silva 28 August 2007 (has links)
Para atenuar o impacto visual, que acomete o motorista ao ingressar em túneis rodoviários durante o período diurno, utiliza-se a luz artificial, com alto nível inicial e gradual diminuição para o interior do túnel. Tal solução apresenta dois inconvenientes imediatos, relacionados ao consumo de energia e à segurança. Devido à radiação solar direta, as imediações da entrada do túnel tornam-se fontes de ofuscamento de elevada intensidade e a iluminação deve estar dimensionada para permitir, ao motorista que se aproxima da entrada do túnel, a visualização de seu interior, implicando em elevado consumo de energia para uma tarefa com pouco requisito visual. Quanto à segurança, na hipótese de falta de energia aumenta-se a probabilidade de acidentes, pois o reflexo do motorista pode ser frear. As soluções arquitetônicas, objeto da pesquisa, correspondem a um Sistema para Adaptação Visual (SAV), implantado no trecho de rodovia aberta anterior à entrada do túnel, que, por um lado, atua nos elementos causadores do problema e, por outro, fornece a iluminação necessária no interior do túnel através das fontes de luz natural (Sol e céu). Para sua concepção, são propostas cinco estratégias. O desempenho do SAV, assim constituído, foi testado em uma aplicação prática nos túneis do trecho Oeste do Rodoanel Mário Covas, sem apresentar os inconvenientes identificados na solução convencional (iluminação artificial). A segurança no ponto crítico ficou garantida por característica intrínseca do sistema. Além de reduzir o consumo, a energia para o período noturno pôde ser gerada pelo próprio SAV, se incorporados módulos fotovoltaicos, e a sazonalidade característica da luz natural é acompanhada pelo sistema, favorecendo o conforto visual por diminuir a faixa em que ocorre o processo de adaptação visual. / The usual adopted solution to defuse the drivers visual impact at the highway tunnel entrance during the daytime, has been the use of electric lighting, with high initial level and gradual reduction towards the internal side of the tunnel. This brings two immediate problems, concerning energy consumption and security. Direct sunlight causes high intensity glare sources around the tunnel entrance, and the lighting level should be enough to allow the interior visibility, when the driver approaches the tunnel, entailing high energy consumption to a low accurate task. Security-wise, in case of power supply failure, collisions possibility increases, due to the drivers instinctive reaction to brake suddenly. Architectural solutions, this research object, are related to a Visual Adaptation System (VAS) positioned on the open road before the tunnel entrance, which, on the one hand, acts into the problem causes, and, on the other, provides the necessary lighting inside the tunnel by natural light sources (Sun and sky). Five strategies are proposed designing the VAS. A practical application on Metropolitan Area Ring Road Mario Covas West segment tunnels checked the so-built VAS performance, not presenting the identified deficiencies in the conventional solution (artificial lighting). The intrinsic system feature assured the critical point security. Besides the consumption reduction, the energy supply for nighttime could be generated by the VAS, if photovoltaic modules are added, and the natural light seasonal feature is followed by the system, favoring the visual comfort by decreasing the visual adaptation process range.
27

Segurança, eficiência energética e conforto visual em emboques de túneis rodoviários: soluções arquitetônicas / Safety, power efficiency and visual comfort at the access zone of highway tunnels: architectural solutions

Norberto Corrêa da Silva Moura 28 August 2007 (has links)
Para atenuar o impacto visual, que acomete o motorista ao ingressar em túneis rodoviários durante o período diurno, utiliza-se a luz artificial, com alto nível inicial e gradual diminuição para o interior do túnel. Tal solução apresenta dois inconvenientes imediatos, relacionados ao consumo de energia e à segurança. Devido à radiação solar direta, as imediações da entrada do túnel tornam-se fontes de ofuscamento de elevada intensidade e a iluminação deve estar dimensionada para permitir, ao motorista que se aproxima da entrada do túnel, a visualização de seu interior, implicando em elevado consumo de energia para uma tarefa com pouco requisito visual. Quanto à segurança, na hipótese de falta de energia aumenta-se a probabilidade de acidentes, pois o reflexo do motorista pode ser frear. As soluções arquitetônicas, objeto da pesquisa, correspondem a um Sistema para Adaptação Visual (SAV), implantado no trecho de rodovia aberta anterior à entrada do túnel, que, por um lado, atua nos elementos causadores do problema e, por outro, fornece a iluminação necessária no interior do túnel através das fontes de luz natural (Sol e céu). Para sua concepção, são propostas cinco estratégias. O desempenho do SAV, assim constituído, foi testado em uma aplicação prática nos túneis do trecho Oeste do Rodoanel Mário Covas, sem apresentar os inconvenientes identificados na solução convencional (iluminação artificial). A segurança no ponto crítico ficou garantida por característica intrínseca do sistema. Além de reduzir o consumo, a energia para o período noturno pôde ser gerada pelo próprio SAV, se incorporados módulos fotovoltaicos, e a sazonalidade característica da luz natural é acompanhada pelo sistema, favorecendo o conforto visual por diminuir a faixa em que ocorre o processo de adaptação visual. / The usual adopted solution to defuse the drivers visual impact at the highway tunnel entrance during the daytime, has been the use of electric lighting, with high initial level and gradual reduction towards the internal side of the tunnel. This brings two immediate problems, concerning energy consumption and security. Direct sunlight causes high intensity glare sources around the tunnel entrance, and the lighting level should be enough to allow the interior visibility, when the driver approaches the tunnel, entailing high energy consumption to a low accurate task. Security-wise, in case of power supply failure, collisions possibility increases, due to the drivers instinctive reaction to brake suddenly. Architectural solutions, this research object, are related to a Visual Adaptation System (VAS) positioned on the open road before the tunnel entrance, which, on the one hand, acts into the problem causes, and, on the other, provides the necessary lighting inside the tunnel by natural light sources (Sun and sky). Five strategies are proposed designing the VAS. A practical application on Metropolitan Area Ring Road Mario Covas West segment tunnels checked the so-built VAS performance, not presenting the identified deficiencies in the conventional solution (artificial lighting). The intrinsic system feature assured the critical point security. Besides the consumption reduction, the energy supply for nighttime could be generated by the VAS, if photovoltaic modules are added, and the natural light seasonal feature is followed by the system, favoring the visual comfort by decreasing the visual adaptation process range.
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Objective assessment of stereoscopic video quality of 3DTV / Évaluation objective de la qualité vidéo en TV 3D relief

Khaustova, Darya 30 January 2015 (has links)
Le niveau d'exigence minimum pour tout système 3D (images stéréoscopiques) est de garantir le confort visuel des utilisateurs. Le confort visuel est un des trois axes perceptuels de la qualité d'expérience (QoE) 3D qui peut être directement lié aux paramètres techniques du système 3D. Par conséquent, le but de cette thèse est de caractériser objectivement l'impact de ces paramètres sur la perception humaine afin de contrôler la qualité stéréoscopique. La première partie de la thèse examine l'intérêt de prendre en compte l'attention visuelle des spectateurs dans la conception d'une mesure objective de qualité 3D. Premièrement, l'attention visuelle en 2D et 3D sont comparées en utilisant des stimuli simples. Les conclusions de cette première expérience sont validées en utilisant des scènes complexes avec des disparités croisées et décroisées. De plus, nous explorons l'impact de l'inconfort visuel causé par des disparités excessives sur l'attention visuelle. La seconde partie de la thèse est dédiée à la conception d'un modèle objectif de QoE pour des vidéos 3D, basé sur les seuils perceptuels humains et le niveau d'acceptabilité. De plus nous explorons la possibilité d'utiliser la modèle proposé comme une nouvelle échelle subjective. Pour la validation de ce modèle, des expériences subjectives sont conduites présentant aux sujets des images stéréoscopiques fixes et animées avec différents niveaux d'asymétrie. La performance est évaluée en comparant des prédictions objectives avec des notes subjectives pour différents niveaux d'asymétrie qui pourraient provoquer un inconfort visuel. / The minimum requirement for any 3D (stereoscopic images) system is to guarantee visual comfort of viewers. Visual comfort is one of the three primary perceptual attributes of 3D QoE, which can be linked directly with technical parameters of a 3D system. Therefore, the goal of this thesis is to characterize objectively the impact of these parameters on human perception for stereoscopic quality monitoring. The first part of the thesis investigates whether visual attention of the viewers should be considered when designing an objective 3D quality metrics. First, the visual attention in 2D and 3D is compared using simple test patterns. The conclusions of this first experiment are validated using complex stimuli with crossed and uncrossed disparities. In addition, we explore the impact of visual discomfort caused by excessive disparities on visual attention. The second part of the thesis is dedicated to the design of an objective model of 3D video QoE, which is based on human perceptual thresholds and acceptability level. Additionally we explore the possibility to use the proposed model as a new subjective scale. For the validation of proposed model, subjective experiments with fully controlled still and moving stereoscopic images with different types of view asymmetries are conducted. The performance is evaluated by comparing objective predictions with subjective scores for various levels of view discrepancies which might provoke visual discomfort.
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Smarta styrsystem kontra statisk belysning / Smart control systems versus static lighting

Lenhammar, Linnéa, Bengtsson, Olivia January 2020 (has links)
Belysning är en väsentlig del i ett fungerande samhälle. Utveckling av belysning går framåt hela tiden, för att bli så användarvänligt som möjligt. Idag kan belysning förutsäga hur utrymmen används med hjälp av information från andra armaturer, så att området blir belyst även om brukaren rör sig precis på gränsen av det belysta området. Att få fram en energieffektiv belysning tillsammans med dagsljus, utan att ge avkall på den visuella komforten är en viktig fråga för beställare av belysning. Visuell komfort är dock mer komplicerat än energibesparing, eftersom det innebär fler faktorer och det gynnsamma resultatet är svårare att uppskatta. Visuell komfort, så som rumsuppfattning beskriver hur vi ser ett rums storlek och form. Något att ha i åtanke är också att rummet inte alltid uppfattas så som det är planerat och tänkt. Idag blir energibesparande styrsystem allt viktigare i kommersiella byggnader då det finns hög potential att minska energiförbrukningen. Utöver att spara energi kan smarta styrsystem också användas för att förbättra ljuskvalitet samt öka produktiviteten. Följande examensarbete undersöker hur smarta styrsystem kan påverka den visuella rumsuppfattningen i kontor, samt om energiförbrukningen förändras av styrsystem, kontra statisk belysning. Undersökningen utgår från två frågeställningar. För att besvara den första frågeställningen som behandlar rumsuppfattning utgår arbetet från en kvantitativ ansats i form av en digital enkätundersökning. Undersökningen omfattar hur belysningen på kontor uppfattas av personal på olika företag som använder sig av smarta styrsystem, jämfört med de som använder statisk belysning. Enkätens syfte var att få reda på deltagarnas uppfattningar om belysningen på sitt kontor. Deltagarna fick svara utifrån sina egna uppfattningar och värderingar. Totalt svarade 37 personer på enkäten. Den andra frågeställningen som handlar om energiförbrukning, beräknas utifrån en armatur från Aura Light. Undersökningen går ut på att jämföra armaturens energiförbrukning då den är statisk och har 100% ljusflöde och sedan titta på energiförbrukningen när den är uppkopplad till ett styrsystem. Därefter jämförs resultaten. De slutsatser som dras i studien kring resultatet av rumsuppfattningen påvisar att det förekom skillnader. Majoriteten av de som hade statisk belysning uppfattade rummet som allmänt och ljust, medan majoriteten med styrsystem uppfattade rummet som lugnt och trivsamt. Detta tyder på att styrsystem i viss mån kan ha en påverkan på hur människor uppfattar ett rums karaktär tillsammans med belysningen. Gällande resultatet kring energiförbrukningen med styrsystem kontra statisk belysning, visar det att det finns potential att spara energi vid byte av belysningssystem på kontor. / Lighting is an essential part of a functioning society. The development of lighting is constantly advancing in order to be as user-friendly as possible. Illumination can predict how spaces are used, using information from other luminaires, so that the area is illuminated even if the user moves exactly on the border of the illuminated area. Obtaining an energy-efficient lighting together with daylight without sacrificing visual comfort is an important issue for lighting buyers. However, visual comfort is more complicated than energy saving, as it means more factors and the favorable result is more difficult to estimate. Visual comfort, such as room perception describes how we see a room's size and shape. Something to keep in mind is that the room is not always perceived as planned and intended. Today energy-saving control systems are becoming increasingly important in commercial buildings as there is a high potential to reduce energy consumption. In addition to saving energy, smart control systems can also be used to improve light quality and increase productivity. This thesis examines how smart control systems can change the visual room perception in offices, as well as how energy consumption is affected by control systems, versus static lighting. The thesis is based on two questions. To answer the first question that deals with room perception, the study is based on a quantitative approach in the form of a digital survey. The survey covers how office lighting is perceived by staff at different companies using smart control systems compared to those using static lighting. The purpose of the survey was to find out the test persons' perceptions of the lighting in their office. The test subjects were given answers based on their own perceptions and values. A total of 37 people answered the survey. The second question is about energy consumption, which is calculated from a luminaire from Aura Light. The study is based on comparing the luminaire, when it is static with 100% flux and then when it is connected to a control system, so as to be able to compare the energy consumption. The conclusions drawn in the study of the result of the room perception show that some differences existed. The majority of those who had static lighting perceived the room as general and bright, while the majority with control systems perceived the room as calm and pleasant. This indicates that control systems can to some extent have an impact on how people perceive a room's character together with the lighting. Regarding the result of energy consumption with control systems versus static lighting, it shows that there is definitely potential to save energy when changing lighting systems in offices.

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