809 research outputs found

    On Realization of Cinema Hall Fire Simulation Using Fire Dynamics Simulator

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    Currently known fire models are capable to describe fire dynamics in complex environments incorporating a wide variety of fire-related physical and chemical phenomena and utilizing large computational power of contemporary computers. In this paper, some issues related to realization of the simulation of fire in a cinema hall with sloping floor and curved ceiling furnished by upholstered seats modelled by FDS (Fire Dynamics Simulator) are discussed. The paper concentrates particularly on the impact of a computational meshes choice on resolving flow field and turbulence in the simulation and indicates problems related to parallelization of the calculation illustrated comparing sequential and parallel MPI calculation using 6 CPU cores. Results of the simulation described and their discussion demonstrate the ability of FDS simulation to capture main tendencies of smoke spread and to forecast the related safety risks realistically

    Analysis of Fire and Smoke Spread in Ki Hajar Dewantara Auditorium, State University of Jakarta, Using Fire Dynamics Simulator

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    Fire behavior and smoke spread are influenced by various factors, including the amount and condition of combustible material, ventilation openings, and ceiling height. A high amount of combustible material in the auditorium poses a significant fire hazard, hence, efforts need to be made to minimize the risk. One approach is to use Computational Fluid Dynamic software, such as Fire Dynamics Simulator (FDS), to model fire combustion. In this research, it provides an overview of the heat release rate (HRR) of fires that occur as well as the effect of differences in ceiling height and the effect of ventilation on fire spread. This research employed Polyurethane foam, commonly used for auditorium seats, as the sample material. Furthermore, it modeled two fire points, one on the 9th floor and the other on the 10th floor, in the middle of seat rows. The development of fire in the modeling was described by the results of visualization, HRR, burning rate, and temperature rise. These results provided insight into the speed at which fire and smoke spread. The starting point on the 9th floor had the highest flame spread rate due to the ceiling jet phenomenon, where a high amount of combustible material caused the ceiling temperature to increase, producing a heat flux that could burn surrounding seats. In both scenarios, the smoke spread rapidly toward the ventilation openings. However, it was denser on the 9th floor as the starting point was farther from the ventilation openings, and the smoke on the 10th floor was less dense

    Computing Aspects of Simulation Based on Conservation Laws Conducted on HPC Cluster

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    The large amount of computing resources required for the simulation of complex natural processes demands a thorough analysis of the efficiency of the calculations and the conditions that influence it. This study investigates computing aspects of fire simulation conducted on a compute cluster. Current fire simulators based on principles of computational fluid dynamics are capable to realistically model majority of complex phenomena related to fire. Fire simulations are highly computationally demanding itself, however, they often lead to extensive parametrical studies requiring high performance computing systems. Smoke stratification and visibility during fire in a road tunnel with two emergency lay-bys are investigated by parametrical study comprising of 24 fire scenarios with the tunnel geometry modifications and various heat release rates and fire locations. Main tendencies of smoke spread in the downstream lay-by are identified and their mutual interactions are analysed. The simulation efficiency of particular simulations is analysed and the reasons of their varied elapsed times are investigated. The analysis indicates that the main reason of this variability are different jet fans velocities influenced by simulation scenario settings

    Risk analysis of LPG tanks at the wildland-urban interface

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    In areas of wildland-urban interface (WUI), especially residential developments, it is very common to see liquefied petroleum gas (LPG) tanks, particularly with a higher ratio of propane, in surface installations serving homes. The most common tanks are between 1 and 5 m3 of capacity, but smaller ones of less than 1 m3 are more frequent. In case of accident, installations may be subject to fires and explosions, especially in those circumstances where legal and normative requirements allow very close exposure to flames from vegetable fuel near LPG tanks. In this project, it is intended to do a comprehensive diagnosis of the problem, addressing the compilation of information on real risk scenarios in historical fires. First, a preliminary presentation of the properties and characteristics of liquefied petroleum gas will be exposed. Its physical and chemical properties, production methodology, pressure and temperature diagrams and important considerations will be defined when using this type of substances in a storage tank of a certain volume. Next, a review of the situation of the existence of LPG tanks in the urban forest interfaces will be exposed. In this case, the main accidents caused by problems with the storage of LPG will be analyzed taking into account the relevance of BLEVE events in this type of incidents. To do this, the main scenarios that could take place in the event of a fire will be presented. Next, the existing legislation on the storage of LPG in these environments in some Mediterranean countries will be studied. In order to develop a comprehensive analysis, the main safety measures and distances will be considered, as well as the awareness of the possibility of vegetation material in the vicinity of LPG storage tanks, which is the main problem that will arise in a possible BLEVE scenario in case of fire. To finalize and facilitate understanding, a comparative table will be included with the aim of visualizing the main advantages and legislative deficiencies between the different countries. Following, the state of the art in terms of modelling LPG accidents at the WUI will be reviewed. Trying to simulate and predict this type of scenarios, it will see the models normally chosen to obtain the tolerable values selected and the answers obtained in each case. Finally, several fire scenarios will be simulated by means of a CFD tool (FDS, Fire Dynamics Simulator). In these simulations, the wind velocity and the distance of the combustible vegetal mass to the tank will be controlled in a WUI fire in which there is a tank of fixed dimensions. The temperature and the heat flow in each of the scenarios will be obtained, and the differences among the location of the sensors and the characteristics of the scenario will be analyzed. As a conclusion, it has been observed that there is a great amount of variables that are not contemplated by the regulatory organisms and that the existing legislation does not guarantee the safety of the population in this type of environment. From the simulations results, variables as temperature should be studied for further characterizations

    The development of a full probabilistic risk assessment model for quantifying the life safety risk in buildings in case of fire

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    In het kader van dit onderzoek is een probabilistisch model ontwikkeld dat het brandveiligheidsniveau van een gebouwontwerp kan kwantificeren en dit berekende veiligheidsniveau kan evalueren aan de hand van een vooraf gedefinieerd aanvaardbaar risicocriterium. De ontwikkelde methodiek kan zowel prescriptieve als op prestatie-gebaseerde ontwerpmethoden objectiveren door rekening te houden met de onzekerheid van ontwerpparameters en de betrouwbaarheid van veiligheidssystemen. Het model bestaat uit zowel een deterministisch als een probabilistisch gedeelte. Het deterministische kader is opgebouwd uit verschillende deelmodellen om zowel de verspreiding van brand en rook, als de interactie met evacuerende personen te simuleren. Verschillende deelmodellen zijn ontwikkeld om het effect van geĂŻmplementeerde veiligheidsmaatregelen zoals detectie, sprinklers , rook- en warmteafvoersystemen, enz. mee in rekening te brengen. Het probabilistische kader is opgebouwd uit modellering van responsoppervlakken, steekproeftechnieken en ontwerp van grenstoestanden. De methodiek maakt gebruik van deze technieken om de nodige rekenkracht te beperken. Het uiteindelijke resultaat wordt vertaald naar een kans op sterfte, een individueel risico en een groepsrisico. De grote meerwaarde van de ontwikkelde methodiek is dat het mogelijk wordt om verschillende ontwerpmethodieken objectief met elkaar te vergelijken en het positieve effect van verbeterde veiligheidstechnieken en redundantie mee in rekening te brengen in het eindresultaat

    Airport Evacuation Strategies for Passengers with Reduced Mobility: Simulation of Structural Configurations

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    Airport emergency cases are becoming more common; therefore, it becomes extremely important to have good emergency and evacuation protocols that are easily and quickly applied so the number of the affected is minimized. The simulation of these emergencies is important to implement evacuation plans and evaluate them. Evacuation plans are often idealized to passengers that in case of emergency are self-sufficient, able to physically attend themselves in their evacuation from the airport, not being optimized for passengers with reduced mobility that require assistance from others, and thus more time for evacuation. This study aims to understand and identify key issues about how passengers with reduced mobility are considered in current evacuation plans and also understand which possible solutions exist to optimize their evacuation. For that, it was performed an airport evacuation simulation using an egress simulation tool and obtained results that allow us to observe that when passengers with mobility impairments have egress routes and exits different from the other occupants, evacuation times decrease. Therefore, both groups of occupants may egress faster and through less congested doors.As situaçþes de emergência em aeroportos são cada vez mais frequentes; sendo assim, tornase extremamente importante ter bons planos de evacuação de fåcil e råpida implementação de maneira a que o número de afetados seja mínimo. A simulação destas situaçþes de emergência Ê importante para implementar e avaliar planos de evacuação. Estes planos são frequentemente idealizados para passageiros que, em caso de emergência são autosuficientes, fisicamente capazes de abandonar o edifício sem ajuda de outros, não sendo otimizados para passageiros com mobilidade reduzida que requerem a assistência de outros e, portanto, mais tempo para a sua evacuação. Este estudo tem como objetivo compreender e identificar as principais questþes no que diz respeito à forma como os passageiros com mobilidade reduzida são considerados nos planos de evacuação atuais e tambÊm entender que soluçþes possíveis existem para otimizar a sua evacuação. Para isso, foram realizadas simulaçþes de evacuação de um terminal de aeroporto, utilizando uma ferramenta de simulação de evacuação e obtiveram-se resultados que permitem observar que, quando os passageiros com dificuldades de mobilidade têm rotas de evacuação e utilizam saídas diferentes dos outros ocupantes, os tempos de evacuação diminuem. Por conseguinte, ambos os grupos de ocupantes são evacuados mais rapidamente e por saídas menos congestionadas

    FACING EXPERIENCE: A PAINTER’S CANVAS IN VIRTUAL REALITY

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    Full version unavailable due to 3rd party copyright restrictions.This research investigates how shifts in perception might be brought about through the development of visual imagery created by the use of virtual environment technology. Through a discussion of historical uses of immersion in art, this thesis will explore how immersion functions and why immersion has been a goal for artists throughout history. It begins with a discussion of ancient cave drawings and the relevance of Plato’s Allegory of the Cave. Next it examines the biological origins of “making special.” The research will discuss how this concept, combined with the ideas of “action” and “reaction,” has reinforced the view that art is fundamentally experiential rather than static. The research emphasizes how present-day virtual environment art, in providing a space that engages visitors in computer graphics, expands on previous immersive artistic practices. The thesis examines the technical context in which the research occurs by briefly describing the use of computer science technologies, the fundamentals of visual arts practices, and the importance of aesthetics in new media and provides a description of my artistic practice. The aim is to investigate how combining these approaches can enhance virtual environments as artworks. The computer science of virtual environments includes both hardware and software programming. The resultant virtual environment experiences are technologically dependent on the types of visual displays being used, including screens and monitors, and their subsequent viewing affordances. Virtual environments fill the field of view and can be experienced with a head mounted display (HMD) or a large screen display. The sense of immersion gained through the experience depends on how tracking devices and related peripheral devices are used to facilitate interaction. The thesis discusses visual arts practices with a focus on how illusions shift our cognition and perception in the visual modalities. This discussion includes how perceptual thinking is the foundation of art experiences, how analogies are the foundation of cognitive experiences and how the two intertwine in art experiences for virtual environments. An examination of the aesthetic strategies used by artists and new media critics are presented to discuss new media art. This thesis investigates the visual elements used in virtual environments and prescribes strategies for creating art for virtual environments. Methods constituting a unique virtual environment practice that focuses on visual analogies are discussed. The artistic practice that is discussed as the basis for this research also concentrates on experiential moments and shifts in perception and cognition and references Douglas Hofstadter, Rudolf Arnheim and John Dewey. iv Virtual environments provide for experiences in which the imagery generated updates in real time. Following an analysis of existing artwork and critical writing relative to the field, the process of inquiry has required the creation of artworks that involve tracking systems, projection displays, sound work, and an understanding of the importance of the visitor. In practice, the research has shown that the visitor should be seen as an interlocutor, interacting from a first-person perspective with virtual environment events, where avatars or other instrumental intermediaries, such as guns, vehicles, or menu systems, do not to occlude the view. The aesthetic outcomes of this research are the result of combining visual analogies, real time interactive animation, and operatic performance in immersive space. The environments designed in this research were informed initially by paintings created with imagery generated in a hypnopompic state or during the moments of transitioning from sleeping to waking. The drawings often emphasize emotional moments as caricatures and/or elements of the face as seen from a number of perspectives simultaneously, in the way of some cartoons, primitive artwork or Cubist imagery. In the imagery, the faces indicate situations, emotions and confrontations which can offer moments of humour and reflective exploration. At times, the faces usurp the space and stand in representation as both face and figure. The power of the placement of the caricatures in the paintings become apparent as the imagery stages the expressive moment. The placement of faces sets the scene, establishes relationships and promotes the honesty and emotions that develop over time as the paintings are scrutinized. The development process of creating virtual environment imagery starts with hand drawn sketches of characters, develops further as paintings on “digital canvas”, are built as animated, three-dimensional models and finally incorporated into a virtual environment. The imagery is generated while drawing, typically with paper and pencil, in a stream of consciousness during the hypnopompic state. This method became an aesthetic strategy for producing a snappy straightforward sketch. The sketches are explored further as they are worked up as paintings. During the painting process, the figures become fleshed out and their placement on the page, in essence brings them to life. These characters inhabit a world that I explore even further by building them into three dimensional models and placing them in computer generated virtual environments. The methodology of developing and placing the faces/figures became an operational strategy for building virtual environments. In order to open up the range of art virtual environments, and develop operational strategies for visitors’ experience, the characters and their facial features are used as navigational strategies, signposts and methods of wayfinding in order to sustain a stream of consciousness type of navigation. Faces and characters were designed to represent those intimate moments of self-reflection and confrontation that occur daily within ourselves and with others. They sought to reflect moments of wonderment, hurt, curiosity and humour that could subsequently be relinquished for more practical or purposeful endeavours. They were intended to create conditions in which visitors might reflect upon their emotional state, v enabling their understanding and trust of their personal space, in which decisions are made and the nature of world is determined. In order to extend the split-second, frozen moment of recognition that a painting affords, the caricatures and their scenes are given new dimensions as they become characters in a performative virtual reality. Emotables, distinct from avatars, are characters confronting visitors in the virtual environment to engage them in an interactive, stream of consciousness, non-linear dialogue. Visitors are also situated with a role in a virtual world, where they were required to adapt to the language of the environment in order to progress through the dynamics of a drama. The research showed that imagery created in a context of whimsy and fantasy could bring ontological meaning and aesthetic experience into the interactive environment, such that emotables or facially expressive computer graphic characters could be seen as another brushstroke in painting a world of virtual reality

    Human factors investigation of the behavioural response to cues of a fire emergency

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    Safety is a significant priority in the contemporary building environment and a focus for many organisations and businesses. Studies have been conducted to review different factors regarding human behaviour during fire evacuation and to utilize the findings to model improved egress procedures and to train occupants on how to evacuate safely. However, much is still unknown about the processes of perceiving and responding to an emergency when cues from different information sources conflict. For example, when a fire evacuation warning has been issued, but the conditions in the area appear to be fine, some of the building occupants may have uncertainty about the correct action to take. There are several cues to an emergency, and some of these may not lead to optimum behaviour. For example, prior research has shown that, in cases where there has been a prevalence of nuisance alarms such as false alarms, occupants may not take action when a real fire alarm is sounded (Proulx, 2007). Moreover, cues to an emergency are often ambiguous and may not be immediately perceived as a threat. This research was conducted to understand the human responses to cues of an emergency in greater detail. It was based on the Protective Action Decision Model (PADM) (Lindell & Perry, 2012), which outlines the research framework conducted within this PhD. PADM provides a formal model of human behaviour during an emergency. Still, it should be expanded into a more comprehensive method of predicting how people behave in a fire or an evacuation (Kuligowski, 2013). The PADM model identifies several stages in the process of emergency detection and response. The first stage defines several factors that influence awareness of a fire scenario; environmental and social contexts, information sources, warning messages, channel access, and receiver characteristics. This PhD conducted a series of experimental studies to identify the influence of some of these factors on user response to fire alarm cues. The research also compared the use of different research methods, specifically, scenario talk through and virtual reality (VR) simulation, to evaluate user behaviour in response to a fire alarm. Four studies have been conducted: the first extended the talk-through method previously used by Lawson et al. (2013) by adding the influence of social cues to the fire scenario. The second study presented the same fire scenario and influence of social cues as study 1, using VR. The pattern of results was consistent with previous literature in that passive behaviour of others resulted in longer evacuation times for the participants. Thus, these methods can reveal the influence of social behaviour on predicting human responses to an emergency. Study three extended the VR scenario to include other factors from stage one of the PADM model. These factors include the source of information during an emergency, the content of the information, and the recipient's characteristics. Therefore, the source of information, level of details, and information channels were all identified as significant in emergencies such as fire evacuations. Finally, the fourth study was conducted to understand the effects of social cues (passive or active conflict) on an authority figure or siren in the evacuation process. Again, three groups were identified and exposed to three different messages in a virtual environment. Results showed that an authority figure in an active conflict situation showed a significant reduction in the evacuation times. Thus, this thesis will show that understanding behavioural response to fire emergency cues has potential value in predicting human behaviour in a fire emergency

    Seeing the Spell: Baroque, Decadence, and a Cinema of Digital-Animated Liberation

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    This dissertation draws on the artistic traditions of seventeenth-century Baroque and nineteenth-century Decadence in seeking to formulate an analytical vocabulary for the aesthetics of digitally-animated spectacle in contemporary cinema. The dissertation seeks to critique binary antinomies of narrative vs. spectacle, and instead propose a concept of narrativized spectacle whereby digital visual effects have brought about a profound liberation in cinemas capacity to envision narrative story-worlds, and depict their workings. It takes the contemporary Hollywood blockbuster as its chief subject for this inquiry, insofar as this is the filmmaking idiom most given to the embrace and deployment of digitally-liberated spectacle, and one which is frequently assumed to be largely bereft of formal and narrative sophistication. This dissertation argues, on the contrary, that the Hollywood blockbusters spectacular nature in fact bears complex utopian implications, and that the crudities which occasionally mar the form in practice are more the result of not being imaginatively hyperbolic enough, rather than being too much so. The dissertations invocation of Baroque and Decadent aesthetics provides a conceptual apparatus for describing this contemporary cinematic idiom of digitized blockbuster spectacle. It identifies a Baroque aesthetic in such stylistic traits as verticality, profusion, and the sublime, as well as narrative themes of transgression of limits, reverence before imposing scale and grandeur, and refusal to ennoble passivity and martyrdom. Likewise, it identifies Decadent aesthetics in stylistics which privilege the gaze, the enclosed and aestheticized space, and formal ritual, as well as narratives ordered around principles of perversity, self-consciousness, and interconnectedness. The ultimate intervention which this dissertation seeks to make, however, is to demonstrate the centrality rather than marginality of animation to cinema, insofar as cel animation has always possessed the graphic freedom to realize any imaginative vision, which digital effects have only recently extended to live-action cinema. All of the aesthetics of Baroque and Decadent blockbuster spectacle that the dissertation traces could be and, the dissertation seeks to show, were deployed in the animated feature years in advance of the liberation of representation that digital effects would bring to live-action
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