1,720,959 research outputs found
Potential of Natural Ventilation and Vegetation for Achieving Low-Energy Tall Buildings in Tropical Climate: An Overview
No full textClimate change and rise in urban temperatures have further increased the cooling load demands for tall buildings located in hot climatic regions. Cooling loads in tall buildings can be reduced by integrating them with natural ventilation (NV) and building integrated vegetation (BIV) techniques. This study explores the potential of NV and BIV for obtaining low-energy buildings by analyzing ten tall buildings as case studies. Buildings are analyzed for NV, BIV, architecture design parameters, and energy savings. The results show that mixed-mode ventilation is the most commonly employed, and circular building plans have the highest potential for energy savings. Furthermore, the combination of NV with sky-gardens (BIV type) is the best strategy for achieving low-energy tall buildings in the tropical climate. The outcomes show that the application of well-researched building physics rules is in practice for making an energy-efficient tall building. These findings may be helpful for designers and planners to develop further strategies and low-cost methods aiming at the development of more sustainable and healthier tall buildings
Adoption of a Performance Evaluation Technique for the Development of a Framework for the Climatic Responsive Urban Design (CRUD)
No full textThis study investigates the effects of urban design elements i.e. street canyon geometry (Canyon
length, width, height, orientation, and SVF) and greenery on the urban microclimate using remote
sensing and computational fluid dynamics-based techniques. The important conclusion derived
from the current research can be used by designers for climate-responsive urban design in case
of the future extension of these cities
EVALUATION OF THE COMBINED EFFECT OF VEGETATION AND NATURAL VENTILATION IN NEARLY ZERO ENERGY MULTI-STOREY BUILDINGS – nZE(ms)B
Get PDFCooling load is the main cause of high energy consumption for tall buildings in tropical climates while the construction of tall buildings is an unavoidable practice due to land scarcity in metropolitan cities. In this regard, the use of natural ventilation (NV) in tall buildings can help reducing the energy consumption. However, this solution can also bring the problem of polluted air that may enter the space to be ventilated. If the air is passed through a system that can absorb pollutants and add more oxygen to the air, the problem may almost be solved. Building integrated vegetation (BIV) systems can help solving this problem. So, if the air entering buildings passes through dense vegetation, it may not only be cleaned but also cooled due to evapotranspiration effect of plants. Furthermore, the choice and location of vegetation can increase or decrease wind speed. Incorporation of the successful implementation of these green strategies lead to the design of nearly zero energy multi-storey buildings (nZEmsB).
A successful implementation of these strategies for an optimized outcome in terms of reduction in cooling load and the performance of NV is evaluated through computational fluid dynamics (CFD) software. A conventional method is to design the building using passive strategies i.e. NV and BIV, and then evaluating the design using a CFD tool to evaluate the efficiency of combined effect of NV and BIV. If the simulation results are not optimal, the design has to be modified and the simulation process has to be repeated. However, this is a time taking approach as the design of a tall building itself is a complex process and any wrong decision regarding spatial planning, overall building configuration and choice of BIV systems may become the reason for the failure of an implementation resorting to this passive technique.
The concept of optimization in Architecture, has brought a novel perspective for the designers to achieve the better design solutions in reduced time. There are many optimization models and tools available for the energy efficient design of buildings, however there is almost no research available regarding the optimization tools available for designing tall buildings incorporating a combination of NV and BIV systems. This research provides an optimization model for finding the optimal design choice for tall buildings using NV and SG as a cooling technique in hot and humid climates.
The deliverables of this research are a decision support framework for the development of the optimization tool, a generative tool, that is capable of developing 3D models of tall buildings with the geometrical characteristics (found in literature) suitable for the best implementation of NV and SG to reduce the cooling load in hot and humid climate; integration of a CFD simulation tool to the generative tool resorting to RhinoCFD for the evaluation of effectiveness of NV; and an optimization algorithm, based on evolutionary algorithms.
This Model is developed using visual programming and scripting on Grasshopper/ Rhino3D. The model does not require users to have in depth knowledge of computational fluid dynamics and still can inform the designer regarding the best design option. It will assist designers to make informed decisions for achieving effective natural ventilation design through building form, orientation, space planning along with allocation of SG at an early stage of design. The results will contribute to the development of energy efficient and energy independent communities
Evaluation of the combined effect of vegetation and natural ventilation in nearly zero energy multi-storey buildings : nZE(ms)B
No full textTese de doutoramento. Arquitetura (Desenho e Computação). Universidade de Lisboa. Faculdade de Arquitetura. 2020Cooling load is the main cause of high energy consumption for tall buildings in tropical climates while the construction of tall buildings1 is an unavoidable practice due to land scarcity in metropolitan cities. In this regard, the use of natural ventilation (NV) in tall buildings can help reducing the energy consumption. However, this solution can also bring the problem of polluted air that may enter the space to be ventilated. If the air is passed through a system that can absorb pollutants and add more oxygen to the air, the problem may almost be solved. Building integrated vegetation (BIV) systems can help solving this problem. So, if the air entering buildings passes through dense vegetation, it may not only be cleaned but also cooled due to evapotranspiration effect of plants. Furthermore, the choice and location of vegetation can increase or decrease wind speed. Incorporation of the successful implementation of these green strategies lead to the design of nearly zero energy multi-storey buildings (nZEmsB). A successful implementation of these strategies for an optimized outcome in terms of reduction in cooling load and the performance of NV is evaluated through computational fluid dynamics (CFD) software. A conventional method is to design the building using passive strategies i.e. NV and BIV, and then evaluating the design using a CFD tool to evaluate the efficiency of combined effect of NV and BIV. If the simulation results are not optimal, the design has to be modified and the simulation process has to be repeated. However, this is a time taking approach as the design of a tall building itself is a complex process and any wrong decision regarding spatial planning, overall building configuration and choice of BIV systems may become the reason for the failure of an implementation resorting to this passive technique. The concept of optimization in Architecture, has brought a novel perspective for the designers to achieve the better design solutions in reduced time. There are many optimization models and tools available for the energy efficient design of buildings, however there is almost no research available regarding the optimization tools available for designing tall buildings incorporating a combination of NV and BIV systems. This research provides an optimization model for finding the optimal design choice for tall buildings using NV and SG as a cooling technique in hot and humid climates. The deliverables of this research are a decision support framework for the development of the optimization tool, a generative tool, that is capable of developing 3D models of tall buildings with the geometrical characteristics (found in literature) suitable for the best implementation of NV and SG to reduce the cooling load in hot and humid climate; integration of a CFD simulation tool to the generative tool resorting to RhinoCFD for the evaluation of effectiveness of NV; and an optimization algorithm, based on evolutionary algorithms. This Model is developed using visual programming and scripting on Grasshopper/ Rhino3D. The model does not require users to have in depth knowledge of computational fluid dynamics and still can inform the designer regarding the best design option. It will assist designers to make informed decisions for achieving effective natural ventilation design through building form, orientation, space planning along with allocation of SG at an early stage of design. The results will contribute to the development of energy efficient and energy independent communities.N/
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Role of Sky-gardens in Improving Energy Performance of Tall Buildings
No full textNatural ventilation has been used as a passive strategy for many decades but only now its importance in tall buildings for addressing the issues of high energy usage and reducing carbon footprints is emerging. Sky-gardens can play an important role in successful implementation of natural ventilation through amplification of natural wind speeds. This study presents a state-of-the-art review on optimization of tall buildings energy performance through incorporation of sky-gardens. Pros and cons of use of natural ventilation for multi-story buildings are highlighted. Details of involved technical difficulties and barriers in the construction and operation process of sky-gardens are also given. Relevant case studies of existing tall buildings around the world using this strategy are analysed to critically evaluate its effect. The results of this study will be useful for incorporation of sky-gardens and improving energy performance in similar buildings. In the end recommendations for future research needed with respect to sky- gardens in tall buildings are also provided
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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