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Sistemas de controle solar e ações de retrofittingNuss, Claudio Andre January 2018 (has links)
Os sistemas de controle solar auxiliam no controle da radiação solar incidente no envoltório, e, de acordo com a NBR 15220-3, é recomendável seu uso para a zona bioclimática 3, na cidade de Porto Alegre. Assim, com a ação de retrofitting, é possível utilizar os sistemas de controle solar como modo de adaptar o envoltório das edificações ao clima local e aos padrões de consumo atuais. Dessa forma, o retrofitting do envoltório pode contribuir com a redução do consumo energético e a dependência de sistemas de refrigeração e aquecimento mecânico. Logo, o objetivo da dissertação é qualificar e quantificar energeticamente os sistemas de controle solar com vistas à redução do consumo energético nos ambientes construídos. Um estudo de caso foi realizado na cidade de Porto Alegre, onde um edifício foi selecionado perante um conjunto de edificações existentes. Com o auxílio de um método expedito de cálculo energético, foi realizada a avaliação energética do envoltório da edificação atual e do seu retrofitting proposto. A edificação passou de nível energético E para nível A, comprovando o êxito do estudo de retrofitting aplicado. A pesquisa concluiu que, alinhado com o encontrado na revisão da literatura, as edificações com grandes aberturas orientadas para oeste são um equívoco de projeto no clima de Porto Alegre e que as ações de retrofitting são uma alternativa de adaptação ao clima local, tornando os edifícios eficientes energeticamente. / Shading systems help to control the incident solar radiation on the envelope, and, according to NBR 15220-3, its use is recommended for the bioclimatic zone 3, in the city of Porto Alegre. Hence, with retrofitting, it is possible to use shading systems as a way of adapting the building envelope to the local climate and current consumption patterns. Thus, the retrofitting of the envelope can contribute to the reduction of the energy consumption and of the dependence on systems of refrigeration and mechanical heating. Therefore, the objective of this dissertation is to qualify and quantify the energy of shading systems in order to reduce energy consumption in built environments. Thus, a case study was conducted in the city of Porto Alegre, where a building was selected from a set of existing buildings. We performed an energetic evaluation of current envelope of buildings and its proposed retrofitting by using a facilitated method for energy calculation. The buildings moved from energy level E to level A, proving the success of the study on the applied retrofitting. We conclude that, as also shown in literature review; buildings with large openings oriented to the west in Porto Alegre are a design misconception due to the city’s climate. Thus, retrofitting actions are alternative ways to adapt to the local climate so that buildings are energy efficient.
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Efeito do sombreamento em variedades de Stylosanthes guianensisLázaro, Carla Cristina Muzeti [UNESP] 03 May 2007 (has links) (PDF)
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lazaro_ccm_me_jabo.pdf: 257891 bytes, checksum: 15139254a062092c31e6dd0caf9ac250 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo deste trabalho foi avaliar a tolerância ao sombreamento de cinco variedades de Stylosanthes guianensis, em duas épocas de semeadura. Utilizou-se o delineamento inteiramente casualizado com quatro repetições e em três e quatro níveis de sombreamento. Aos 60 dias após o início de cada experimento foram avaliadas as características: altura de planta, número de ramos, de folhas e de nódulos, área foliar, teores de clorofila a e b, teor total de clorofila, razão entre os teores de clorofilas a/b, comprimento de raiz, massa seca de ramos, de folhas e de raiz. Nas duas épocas de avaliação, a variedade vulgaris cv. Pucallpa apresentou maiores valores para as características estudadas, sendo o melhor desempenho das variedades em 30% de sombreamento na primeira avaliação e em 50% na segunda. Os resultados obtidos indicaram que há variabilidade de resposta ao sombreamento entre as variedades de Stylosanthes guianensis. / The objective of this work was to evaluate the tolerance to the shading of five varieties of Stylosanthes guianensis, at two times of sowing. Treatments were set in complete randomized design with four repetitions, and three and four levels of shading. To the 60 days after the beginning of each experiment had been measured the traits: height of plant, number of branches, of leaves and nodules; leaf area; content of chlorophyll a and the b, total content of chlorophyll, reason enters contents of chlorophyll a/b, root length; dry mass of branches, of leaves and root. At the two times of evaluation, the variety vulgaris cv. Pucallpa had presented raised values for the studied traits, being the best performance of the varieties in 30% of shading in the first evaluation and 50% in second. The gotten results had indicated that it has variability of reply to the shading between the varieties of Stylosanthes guianensis.
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Desenvolvimento de bromélias em ambientes protegidos com diferentes alturas e níveis de sombreamento. / Growth of bromeliads in greenhouses with different heights and levels of shading.Pauletti Karllien Rocha 04 June 2002 (has links)
O objetivo geral deste trabalho foi avaliar o efeito de diferentes alturas de ambientes protegidos e de diferentes níveis de sombreamento no cultivo de bromélias das espécies Aechmea fasciata e Guzmania lingulata. O experimento foi conduzido no período de 03 de abril de 2001 a 3 de abril de 2002, em dois ambientes protegidos, instalados, no sentido leste -oeste, na área experimental do Núcleo de Pesquisa em Ambiência (NUPEA), junto ao Departamento de Engenharia Rural, da Escola Superior de Agricultura "Luiz de Queiroz", Universidade de São Paulo, em Piracicaba, SP. Ambos os ambientes protegidos possuíam dimensões de 6,4m de largura por 17,5m de comprimento, com alturas diferenciadas, de 3,0m e de 3,5m. Esses ambientes possuíam cobertura plástica de polietileno de baixa densidade (PEBD), com 150m de espessura. A avaliação dos níveis de sombreamento aplicados às plantas no interior dos ambientes foi viabilizada pelo uso de telas de polipropileno de cor preta que proporcionaram sombreamentos de 18, 40, 60 e 80%. As mudas utilizadas no experimento foram obtidas através de micropropagação, e transplantadas para os vasos plásticos com uma idade aproximada de 90 dias em condições ex vitro. Avalio-se nos ambientes protegidos com diferentes alturas, a temperatura do ar, a umidade relativa, a temperatura de globo negro, a carga térmica radiante e a intensidade luminosa. Essa avaliação foi realizada pela leitura direta nos seguintes instrumentos: psicrômetros, termômetro de globo negro, anemômetro e luxímetro digital. Foram ainda realizadas coletas de dados de temperatura do ar, de umidade relativa e de radiação solar global, através de uma estação meteorológica automática. O desenvolvimento das plantas, sob os diferentes níveis de sombreamento e as diferentes alturas dos ambientes, foi avaliado através do número de folhas, da altura das plantas, da largura das folhas e do diâmetro da roseta. Nas condições em que foi conduzido o experimento, concluiu-se que não houve diferença significativa nos ambientes com diferentes alturas, quando relacionou-se a umidade relativa do ar, a temperatura do ar, a temperatura de globo negro, a carga térmica de radiação, a luminosidade e a radiação solar global. A A. fasciata, submetida aos vários níveis de sombreamento, mostrou um melhor desenvolvimento sob as telas de 40%, enquanto que para G. lingulata as telas de 60 e 80% de sombreamento proporcionaram desenvolvimento semelhante das plantas. / The objective of this research was to evaluate the effect of different greenhouses heights and levels of shading on the growth of Aechmea fasciata and Guzmania lingulata (Bromeliaceae). The experiment was done from march 26'th of 2001 to april third of 2002, in two greenhouses, built in east-west orientation, at the experimental area of Nucleos of Environment Research NUPEA, Rural Engineering Department, "Luiz de Queiroz" College of Agriculture, University of São Paulo, Piracicaba, Brazil. Greenhouses measured: 6.4m in width, 17.5m in length and heights of 3.0m and 3.5m. They were covered with 150m thick low density polyethylene (PEBD). Black polypropylene cloth providing shading of 18%, 40%, 60%, and 80% was used. The plants used in the experiment were obtained through micropropagation and transplanted to plastic pots at approximately 90 days after ex vitro culture. The air temperature, the relative humidity, the black globe temperature, the radiant thermal load, and light intensity were evaluated inside the greenhouses. These evaluations were carried out through the direct reading from the following instruments: psycrometers, black globe thermometer, anemometer and digital luximeter. Air temperature, relative humidity and global solar radiation were also obtained through sensors connected to an automatic meteorological station. The development of the plants under different levels of shading and different heights was evaluated according to the number of leaves, height of plants, width of leaves, and the diameter of the rosette. Under the conditions used for the experiment, it can be concluded that the 3.5m high greenhouse showed lower air relative humidity when compared to the 3.0m high greenhouse. Plants of A. fasciata growing under different levels of shading had a better development under 40% cloths, while G. lingulata showed a more vigorous grouth under 60% and 80% of shading.
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Nutrients, Salinity and Shading in an Algae Growth ModelGao, Song, Gao, Song January 2017 (has links)
Microalgae have been recognized as one of the most promising feedstocks for biofuel production. In the Regional Algal Feedstock Testbed (RAFT) project, scientists and engineers have been working on various topics including improving cultivation strategy, optimizing culture system, developing production models, controlling contamination, and so on. One of the objectives in this project is to improve an algae cultivation model for productivity prediction and techno-economic assessment. The model adopted in this project is the Huesemann Algae Biomass Growth (HABG) model which is based upon strain characteristics obtained from laboratory experiments. However, because the model assumed optimal growth conditions for microalgae, it over-predicted biomass growth significantly when its results were compared to outdoor raceway experimental data. For example, in an attempt to control contamination, culture salinity was raised to a high level. The high salinity may limit growth of contaminants, but it also causes stress on salinity sensitive strains of microalgae. Researchers also lowered nutrient fertilization rates in order to minimize fertilizer input and cost of production. However, this introduced nutrient stress and lowered the growth rate of microalgae. In the raceways used in the RAFT project, shade covered a large fraction of the culture surface when solar angle was low. All of these growth limiting factors were not included in the original model. In this study, salinity stress, nitrogen limitation and shading effect were incorporated into the model. Growth rate reduction due to salinity stress and nitrogen limitation were quantified through laboratory experiments. An innovative concept of nitrogen availability was introduced, which estimates the nitrogen stress factor without measuring intracellular nitrogen. The shading factor was calculated based on solar position during the day and raceway geometry. The modification greatly improved the model accuracy. In addition to HABG model improvements, this study also focused on nutrient application. Several experiments were performed in both indoor and outdoor systems to improve field cultivation practices. The nitrogen experiments provided not only the growth kinetics that improved the growth model, but also demonstrated that high lipid accumulation rate was triggered at different nitrogen stress intensities for different strains. Stress should be applied depending the saturation demand of the final lipid product. In order to quickly evaluate the nitrogen status in the culture, a nitrogen stress index using optical density was proposed. Experiments in RAFT experiments supported the feasibility of applying the method in outdoor cultivation. This study also investigated maximum biomass yields of nitrogen and phosphorus for producing S. obliquus biomass with indoor bench scale experiments. The results were tested in the outdoor raceways and demonstrated the potential of using fertilizer more efficiently in microalgae cultivation.
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Effects of irrigation and shading on fruit yield and quality in mangoMthembu, Gugulethu Jay 10 November 2005 (has links)
Mangifera indica L. cv. Kent trees were subjected to five irrigation treatments during the 2000/2001 growing season with the aim of assessing the effects of irrigation on tree productivity and fruit quality. Two progressively reduced irrigation treatments (75 and 50% of the amount of irrigation water applied to the control), a control (100% field capacity), a regulated deficit irrigation (RDI) treatment and a farm control were compared with each other. Fruit yield, number and mean fruit weight were not significantly influenced by the different irrigation treatments. Peel colour and storage potential were improved in the reduced irrigation treatments. The RDI treatment improved the total soluble solids concentration (TSS) of fruits but increased the occurrence of split pit. Fruit firmness was not significantly influenced by the different irrigation treatments. In the second experiment, 'Kent' trees were covered with white shade netting of four mesh densities (50, 75, 100 and 125 g m-2) on a long¬term basis, while control trees remained uncovered. During the 2000/2001 growing season, light shading (50 g m-2) increased the yield and fruit numbers above that of control trees, while, heavier shading decreased the yield and fruit number below that of the control with the most dense net (125 g m-2) having the greatest affect. Peel colour, firmness and total soluble solids (TSS) at harvest were not affected by shading while the heaviest shade (125 g m-2) reduced storage potential of the fruit. Shading improved the appearance of fruits through the reduction of split pit, sunburn and wind damage. No fruit damage caused by bacterial black spot was observed in any of the shade treatments or the control. / Dissertation (M Inst Agrar (Horticultural Science))--University of Pretoria, 2006. / Plant Production and Soil Science / unrestricted
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Analysering av Variable Rate Shading's bildbaserad skuggning i uppskjuten sammansättning av ljussättning : En jämförelse mellan bildbaserad skuggning och enhetlig skuggning för spel / Analysing Variable Rate Shading’s Image-Based Shading in Deferred Lighting Composition : A comparison between image-based shading and uniform shading for gamesLundbeck, Filip January 2020 (has links)
Bakgrund. Kostnaden att ljussätta en pixel blir dyrare med realistiska spel. Upplösningen av spel är ökas i samma tak för att visa upp detaljerna. Att rendera en blidruta för användare blir därför allt dyrare. Dynamic Resolution Rendering är ett sätt att enhetligt minska upplösningen för att öka prestandan fast med den nyligen släppta variable rate shading finns det nya sätt att öka prestandan men med mindre påverkan på bildkvalitén.Syfte. Målet är att se om adaptiv ljussätningsning via Variable Rate Shading kan tillåta liknande eller bättre resultat, med hänsyn på prestanda och bildkvalité, jämfört med den enhetliga ljussättningen av Dynamic Resolution Rendering. Metod. Denna undersökning kommer att utföras genom att implementera Variable Rate Shading och Dynamic Resolution Rendering i en Deferred Renderer. Prestandan kommer att mätas genom att ta tid för ljussättningspasset och bildkvalitén kommer att mätas genom att jämföra den slutgiltiga bildrutan av båda teknikerna mot den ursprunliga upplösningen via SSIM. Resultat. Övergripande visade Variable Rate Shading jämförelsebar prestanda när den applicerades på Deferred Lighting passet fast hade bildkvalité som liknande mer den originalupplösningen. Slutsatser. Variable Rate Shading visade sig vara jämförbar i prestandan som i jämförelse med dynamic resolution rendering, fast gav bättre möjlighet att bibehålla bildkvalitén. / Background. The shading cost of a pixel is only getting more expensive with more realistic games. Resolution of games is equally pushed to display the all the details in a scene. This causes rendering a frame to be very expensive. Dynamic Resolution Rendering has been used to uniformly decreases resolution to gain performance but with the new release of image-based shading through Variable Rate Shading could be the new way to gain performance with less impact on image quality. Objectives. The goal is to see if the adaptive shading possibilities of Variable Rate Shading can show equal or better results, in regards to performance and image quality, compared to the uniform shading of Dynamic Resolution Rendering. Methods. This investigation is performed by implementing them into the Deferred Lighting pass in a Deferred Renderer. The performance is measured by the render pass time of the Deferred Lighting and the image quality is measured by comparing the final frames of Variable Rate Shading and Dynamic Resolution Rendering against the original resolution through SSIM. Results. Overall Variable Rate Shading show comparable performance results to Dynamic Resolution Rendering but the image quality is closer to the original resolution. Conclusions. Using image-based shading on the deferred lighting pass allow the possibility of extracting similar performance gains as dynamic resolution rendering but allows maintaining higher image quality.
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Maximizing performance gain of Variable Rate Shading tier 2 while maintaining image quality : Using post processing effects to mask image degradationLind, Fredrik, Diaz Escalante, Andrés January 2021 (has links)
Background. Performance optimization is of great importance for games as it constrains the possibilities of content or complexity of systems. Modern games support high resolution rendering but higher resolutions require more pixels to be computed and solutions are needed to reduce this workload. Currently used methods include uniformly lowering the shading rates across the whole screen to reduce the amount of pixels needing computation. Variable Rate Shading is a new hardware supported technique with several functionality tiers. Tier 1 is similar to previous methods in that it lowers the shading rate for the whole screen. Tier 2 supports screen space image shading. With tier 2 screen space image shading, various different shading rates can be set across the screen which gives developers the choice of where and when to set specific shading rates. Objectives. The aim of this thesis is to examine how close Variable Rate Shading tier 2 screen space shading can come to the performance gains of Variable Rate Shading tier 1 while trying to maintain an acceptable image quality with the help of commonly used post processing effects. Methods. A lightweight scene is set up and Variable Rate Shading tier 2 methods are set to an acceptable image quality as baseline. Evaluation of performance is done by measuring the times of specific passes required by and affected by Variable Rate Shading. Image quality is measured by capturing sequences of images with no Variable Rate Shading on as reference, then with Variable Rate Shading tier 1 and several methods with tier 2 to be compared with Structural Similarity Index. Results. Highest measured performance gains from tier 2 was 28.0%. The result came from using edge detection to create the shading rate image in 3840x2160 resolution. This translates to 36.7% of the performance gains of tier 1 but with better image quality with SSIM values of 0.960 against tier 1’s 0.802, which corresponds to good and poor image quality respectively. Conclusions. Variable Rate Shading tier 2 shows great potential in increasing performance while maintaining image quality, especially with edge detection. Postprocessing effects are effective at maintaining a good image quality. Performance gains also scale well as they increase with higher resolutions. / Bakgrund. Prestandaoptimering är väldigt viktigt för spel eftersom det kan begränsa möjligheterna av innehåll eller komplexitet av system. Moderna spel stödjer rendering för höga upplösningar men höga upplösningar kräver beräkningar för mera pixlar och lösningar behövs för att minska arbetsbördan. Metoder som för närvarande används omfattar bland annat enhetlig sänkning av skuggningsförhållande över hela skärmen för att minska antalet pixlar som behöver beräkningar. Variable Rate Shading är en ny hårdvarustödd teknik med flera funktionalitetsnivåer. Nivå 1 är likt tidigare metoder eftersom skuggningsförhållandet enhetligt sänks över hela skärmen. Nivå 2 stödjer skärmrymdsbildskuggning. Med skärmrymdsbildskuggning kan skuggningsförhållanden varieras utspritt över skärmen vilket ger utvecklare valmöjligheter att bestämma var och när specifika skuggningsförhållanden ska sättas. Syfte. Syftet med examensarbetet är att undersöka hur nära Variable Rate Shading nivå 2 skärmrymdsbildskuggning kan komma prestandavinsterna av Variable Rate Shading nivå 1 samtidigt som bildkvaliteten behålls acceptabel med hjälp av vanligt använda efterbearbetningseffekter. Metod. En simpel scen skapades och metoder för Variable Rate Shading nivå 2 sattes till en acceptabel bildkvalitet som utgångspunkt. Utvärdering av prestanda gjordes genom att mäta tiderna för specifika pass som behövdes för och påverkades av Variable Rate Shading. Bildkvalitet mättes genom att spara bildsekvenser utan Variable Rate Shading på som referensbilder, sedan med Variable Rate Shading nivå 1 och flera metoder med nivå 2 för att jämföras med Structural Similarity Index. Resultat. Högsta uppmätta prestandavinsten från nivå 2 var 28.0%. Resultatet kom ifrån kantdetektering för skapandet av skuggningsförhållandebilden, med upplösningen 3840x2160. Det motsvarar 36.7% av prestandavinsten för nivå 1 men med mycket bättre bildkvalitet med SSIM-värde på 0.960 gentemot 0.802 för nivå 1, vilka motsvarar bra och dålig bildkvalitet. Slutsatser. Variable Rate Shading nivå 2 visar stor potential i prestandavinster med bibehållen bildkvalitet, speciellt med kantdetektering. Efterbearbetningseffekter är effektiva på att upprätthålla en bra bildkvalitet. Prestandavinster skalar även bra då de ökar vid högre upplösningar.
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Cooperative Shape from Shading and Stereo for 3D ReconstructionFortuna, Jeff 04 1900 (has links)
This thesis presents a survey of techniques to obtain the depth component from two-dimensional (2D) images. Two common techniques - stereo and shape from shading are examined here. Their performance is compared with an emphasis on noting the fundamental limitations of each technique. An argument is presented which suggests an adjustment of the paradigm with which stereo and shape from shading have been treated in three-dimensional vision. The theoretical development of the stereo and lighting models is followed by experiments illustrating use of these models for a variety of objects in a scene. A comparison of the results provides a motivation for combining them in a particular way. This combination is developed, and its application is examined. Using the model that is consistent for both shape and lighting, significant improvement over either stereo or lighting models alone is shown. / Thesis / Master of Engineering (ME)
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SHAPE FROM SHADING AND PHOTOMETRIC STEREO ALGORITHMIC MODIFICATION AND EXPERIMENTSPRASAD, PARIKSHIT 31 March 2004 (has links)
No description available.
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An Embedded Shading LanguageQin, Zheng January 2004 (has links)
Modern graphics accelerators have embedded programmable components in the form of vertex and fragment shading units. Current APIs permit specification of the programs for these components using an assembly-language level interface. Compilers for high-level shading languages are available but these read in an external string specification, which can be inconvenient.
It is possible, using standard C++, to define an embedded high-level shading language. Such a language can be nearly indistinguishable from a special-purpose shading language, yet permits more direct interaction with the specification of textures and parameters, simplifies implementation, and enables on-the-fly generation, manipulation, and specification of shader programs. An embedded shading language also permits the lifting of C++ host language type, modularity, and scoping constructs into the shading language without any additional implementation effort.
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