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Yu, Caroline, and Ann-Mia Zhang. "The different viewing experiences between special and visual effects." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-254786.
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Computer graphics field is rapidly growing and is widely used in many industries, especially in cinematics. The visual effects, which is a part of the field, have become more affordable in comparison to special effect. By using more visual effects, safety during the shooting increases and the use of resources decreases. However, the field is still young and there are a lot of flaws to consider when creating such an effect. It is important that CGI in movies are created in such a way that it does not disrupt the viewing experience unless it’s done on purpose. Therefore, CGI in a real-life setting should look real. To create CGI that is closer to reality, this study examines the differences between special effects and visual effects in the aspect of the viewing experience. To investigate this question, we conducted an experiment following a semi-structured interview. 13 students participated in this study where they had to watch video clips representing the special respective visual effect. During the experiment, they did a self- report by filling in a questionnaire. A Valence-Arousal model was used to examine the subject’s emotional reactions. The result suggests that there are no significant differences between the two effects in regard to an emotional reaction. However, it shows that the visual effect had flaws of being too plastic and too perfect which makes it less convincing compared to the special effects. In contrary, the special effects do not have the ability to be exaggerating, which in turn makes it more exciting to watch the visual effects. Although this study does not solve any flaws, it highlights those that need to be fixed for the goals of improving CGI.Datorgrafik är ett ständigt växande ämne och tekniken kan appliceras så många olika sätt, speciellt inom film. Visuella effekter som är en del av ämnet som har blivit ett mer prisvärt alternativ i jämförelse till specialeffekter. Genom att använda mer visuella effekter, har säkerheten i filmandet ökat och användningen av resurser minskat. Men datagrafiksämnet är fortfarande relativt ny och det finns många brister att tänka på när det gäller att skapa en visuell effekt. Det är viktigt att CGI i filmer är skapad på sådant sätt att den inte stör tittarupplevelsen, såvida det inte är med mening. CGI i en verklighetstrogen miljö bör därför se verklighetstrogen ut. För att skapa CGI som är närmare verkligheten ska denna studien undersöka skillnaden mellan specialeffekter och visuella effekter baserad på tittarupplevelsen. För att undersöka denna fråga har vi utfört ett experiment med följd av en semi-strukturerad intervju. 13 studenter deltog denna studie där de har kollat på videoklipp med specialeffekter respektive visuella effekter. Under experimentet fick de fylla i en enkät där de utvärderar deras reaktion till klippen samt vad de tyckte om respektive klipp. En Valence-Arousal-modell användes för att undersöka deltagarnas emotionella reaktion. Resultatet visar att det inte är någon signifikant skillnad mellan de två effekterna när det gäller den emotionella reaktionen. Däremot indikerar att de visuella effekterna var för konstlad samt för perfekt i jämförelse till specialeffekter. Dessa nackdelar gjorde effekten mindre övertygande. Emellertid kan specialeffekterna inte överdrivas i samma skala som visuella effekter vilket gör den visuella effekten mer spännande. Denna studie löser inte de problem som visuella effekter har idag, men den tar fram problem som behöver fixas för att förbättra tekniken.
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Sanderson, Mariana Welly. "Effects of visual degradation on audio-visual speech perception." Thesis, Birkbeck (University of London), 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.404941.
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Audio-visual speech recognition is considered to be a dynamic process that uses auditory and complementary visual speech cues. These are the products of the stream of timed and targeted movements of the articulators in the vocal tract used to produce speech. If the visual aspect of speech is absent or degraded, speech recognition in noise may deteriorate; this was used as a tool to investigate the visual aspect of speech recognition in the following experiments. A series of shadowing and recall experiments assessed the effects of frame rate (temporal) and greyscale level (spatial) variations to the visual aspect of audio-visual presentations of sentences spoken in noisy backgrounds by three, evenly illuminated, speakers. There was a significant decline in shadowing accuracy as the frame rate of presentation fell that was related to the importance of temporal synchrony in audiovisual speech. Shadowing and recall experiments, with recordings from one speaker in two illumination conditions and two greyscale levels, revealed that performance accuracy depended on level of illumination in both tasks, for the audio-visual experimental condition and the audio-alone control condition. Moreover in poor illumination, there was significantly less accurate recall performance at the lower greyscale level. This was related to level of spatial facial information that may be used in speech recognition. Shadowing and recall accuracy of sentence's keywords was related to their degree of visible speech-related movement. Audio-visual shadowing accuracy varied little across the range of movements, but audio-alone shadowing accuracy declined significantly as the degree of movement increased. Visual and auditory target characteristics of words associated with differing audio-visual advantage and degrees of visual movement were determined. The findings were considered in the context of a dynamic model of speech processing, which is dependent on patterns of the timings and targets of the auditory and visual speech signals.
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Ryu, Jae Hyung. "Reality & effect a cultural history of visual effects /." unrestricted, 2006. http://etd.gsu.edu/theses/available/etd-03292007-172937/.
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Thesis (Ph. D.)--Georgia State University, 2006.Title from file title page. Ted Friedman, committee chair; Kathy Fuller-Seeley, Angelo Restivo, Jung-Bong Choi, Alisa Perren, committee members. Electronic text (249 p.) : digital, PDF file. Description based on contents viewed Oct. 29, 2007. Includes bibliographical references (p. 236-249).
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Ryu, Jae Hyung. "Reality & Effect: A Cultural History of Visual Effects." Digital Archive @ GSU, 2007. http://digitalarchive.gsu.edu/communication_diss/13.
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The purpose of this dissertation is to chart how the development of visual effects has changed popular cinema¡¯s vision of the real, producing the powerful reality effect. My investigation of the history of visual effects studies not only the industrial and economic context of visual effects, but also the aesthetic characteristics of the reality effect. In terms of methodology, this study employs a theoretical discourse which compares the parallels between visual effects and the discourse of modernity/postmodernity, utilizing close textual analysis to understand the symptomatic meanings of key texts. The transition in the techniques and meanings of creating visual effects reflects the cultural transformation from modernism to postmodernism. Visual effects have developed by adapting to the structural transformation of production systems and with the advance of technology. The studio system strongly controlled the classical Hollywood cinema by means of the modern economic production system of Fordism. Breakdown of Hollywood classicism as a production system gave rise to the creation of digital effects with the rise of the concept of the blockbuster and with the development of computer technologies. I argue that the characteristic feature of time-space compression, occurring in the process of the transition from Fordism to flexible accumulation, clearly reflects that of compression of multi-layered time and space, generated in the development process from analog visual effects, such as trick, rear and front projection, to the digital effects, such as rotoscoping and CGI animation. While the aesthetics of analog visual effects, without computing, can be compared to a Fordist production system, digital effects, which hugely rely on CGI manipulation, are examples of flexible accumulation. As a case study of the local resistance or alternative of Hollywood today, I examine the effects-oriented Korean nationalist blockbuster. The Korean nationalist blockbuster films have sought large-scale filmmaking and presentation of spectacular scenes, including heavy dependence on the use of special effects, which is frequently considered a Hollywood style. This paradoxical combination of peculiar Korean subjects and Hollywood style can be viewed as a form of cultural jujitsu, taking advantage of the force of the dominant culture in order to resist and subvert it.
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Wrenninge, Magnus. "Fluid Simulation for Visual Effects." Thesis, Linköping University, Department of Science and Technology, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-2347.
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This thesis describes a system for dealing with free surface fluid simulations, and the components needed in order to construct such a system. It builds upon recent research, but in a computer graphics context the amount of available literature is limited and difficult to implement. Because of this, the text aims at providing a solid foundation of the mathematics needed, at explaining in greater detail the steps needed to solve the problem, and lastly at improving some aspects of the animation process as it has been described in earlier works.
The aim of the system itself is to provide visually plausible renditions of animated fluids in three dimensions in a manner that allows it to be usable in a visual effects production context.
The novel features described include a generalized interaction layer providing greater control to artists, a new way of dealing with moving objects that interact with the fluid and a method for adding source and drain capabilities.
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Connolly, Desmond Michael. "Visual effects of respiratory disturbance." Thesis, City University London, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.514496.
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Spencer, Martin Bramwell Howard. "Effects of noise on visual orienting." Thesis, Durham University, 1987. http://etheses.dur.ac.uk/6697/.
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Eleven experiments are reported which examine the effects of 90 dB (A) white noise on the processes which govern orienting of attention in visual space. The selectivity hypothesis argues that noise alters the priorities which govern stimulus selection so that subjectively dominant aspects of the environment are attended to more fully than those which are non-dominant. The applicability of this hypothesis is examined with regard to attentional orienting. Three experimental paradigms are used. The first involves a central cue presented immediately prior to target onset. In the absence of eye movements reaction times to expected targets are faster than to unexpected targets, but noise has no effects on performance. It is concluded that the power of the central alerting cue is focussing attention in a maximal fashion and noise has no further effect on policies of allocation. A second task design involves the presentation of positional information prior to a block of trials. Under such conditions subjects fail to maintain orienting as trials continue. Noise enhances the ability to maintain orienting over time. This effect is discussed in the light of the selectivity hypothesis. It is argued that the inability to maintain orienting is not due to the inhibition which arises as a result of successive responding. Rather it is due to the difficulty involved in maintaining an active orientation. The third paradigm involves orienting to specific locations on the basis of information stored in short-term memory. When recall of this information is aided by a visual warning signal occurring prior to target onset noise has no effect on performance. Without this signal, noise alters performance and these data are compared to predictions based upon the selectivity hypothesis. These effects are discussed in terms of a noise-induced change in the strategy of performance, rather than an effect which is mechanistic.
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Medwetz, Abigail. "The Effects of Color on Visual Perception and Visual Clutter." Kent State University Honors College / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ksuhonors1556373271322324.
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Hailston, Kenneth W. "Effects of Priming Visual Relatedness and Expectancy on Visual Search Performance." Thesis, Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/7498.
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The current study examined two means of reducing uncertainty in visual search: 1) visual relatedness of a prime to the target (a data-driven, bottom-up processing) and 2) expectancy (a top-down process based on the proportion of validly primed trials). The two processes were decoupled using a short and a long inter-stimulus interval (ISI) to examine their time course in visual search. Competing hypotheses were contrasted in order to determine whether relatedness is associated with iconic memory (Neely, 1977) or a longer lasting visual-structural implicit memory (Schacter and Cooper, 1995) and what role participant expectancy plays in visual search performance.
Twelve participants engaged in a discrimination task and a visual search task. The obtained results suggest that visual relatedness is a bottom-up process, probably mediated by a short-term iconic store that affects search performance early, but whose effects rapidly decay. They also suggest that expectancy is a top-down process that requires time to build up before it can affect visual search performance, but whose effects are more long lasting than visual relatedness.
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Ruijter, Judith. "Effects of caffeine on visual attention." Amsterdam : Amsterdam : Universiteit van Amsterdam, Faculteit der Maatschappij en Gedragswetenschappen, afdeling Psychologie ; Universiteit van Amsterdam [Host], 2000. http://dare.uva.nl/document/81787.
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Flückiger, Barbara. "Visual Effects : Filmbilder aus dem Computer /." Marburg : Schüren, 2008. http://www.gbv.de/dms/weimar/toc/529501759_toc.pdf.
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Hinton, Jane. "Neighbourhood effects during visual word recognition." Thesis, University of Nottingham, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363914.
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Gontijo, Possidonia de Freitas Drumond. "Familiarity effects in visual word recognition." Thesis, University of Edinburgh, 1998. http://hdl.handle.net/1842/21263.
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This thesis is an investigation of two different aspects of familiarity processes involved in visual word recognition. The first is how capitalisation influences visual word recognition. The second is the role played by onset, nucleus and coda in nonword recognition. A familiar aspect of proper names in English, is that they are printed with an initial capital letter. Two experiments investigated the effects of the capitalisation of the initial letter of nonwords. It was found that subjects generate fewer pronunciations for initially capitalised nonwords than for those which were not capitalised. I suggest that in English initial capitalisation acts as a cue strong enough to prompt readers to perceive unfamiliar strings of letters as belonging to the category of proper names. As a result, the phonological domain used to retrieve the pronunciation of initially capitalised strings becomes more restricted than that used for the non-capitalised unfamiliar strings. These results extend the applicability of Brennen's theory for proper names, which is based on the size of the set of plausible phonologies of a word. In a third experiment, pairs of nonwords had their familiar visual appearance manipulated in terms of first and last letter capitalisation, in a same-different matching task. Faster response times were obtained for those nonword pairs that kept a more familiar aspect (e.g., pairs in which the first letter was capitalised as opposed to others in which the last letter was capitalised). These results are explained in terms of Besner and Jonhston (1989) "orthographic familiarity route". I propose the transformation model as an explanation for the mechanisms by which this route operates. Nonwords are an important aspect of this thesis. A new algorithm was developed for the creation of monosyllabic nonwords in which the frequency of their onsets, nuclei and codas could be controlled carefully. This gave us the opportunity to study the influence of orthographic neighborhood in visual word recognition. The findings here are in agreement with previous studies which show the recognition of an item to be influenced by the presence of neighbours. It has been hypothesized that familiarity effects in visual word recognition can only be found in tasks where identification mechanisms are not implicated. Here, a new category of words, namely brand names, was used to test this hypothesis. There are many reasons why brand names are a more appropriate class of words than acronyms to be used in this type of investigation. The results obtained confirm the hypothesis above. Previously, acronyms had been the only class of words used to test this hypothesis. Finally, a computational assessment of the nature of the mappings from letterto- sound in British English was carried on. A program was developed to estimate the pronunciation of any string of English graphemes based on the probabilities of grapheme-phoneme correspondences. The algorithm was assessed by examining its behavior for nonwords. This was done by using a corpus of nonword transcriptions, collected in an experiment with trained phoneticians. The results confirm the fact that the statistical information about grapheme-phoneme correspondences alone is not sufficient to predict English pronunciation. Also, a method was developed that allows the quantification of the different orthographic depth for various languages.
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Skelly, June J. "Pacing visual attention : temporal structure effects /." The Ohio State University, 1992. http://rave.ohiolink.edu/etdc/view?acc_num=osu148778086540915.
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Abler, Jensen. "Rendering and Compositing for Visual Effects." Digital Commons @ East Tennessee State University, 2015. https://dc.etsu.edu/honors/232.
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The methods used to create visual effects for feature film production are quickly evolving. Cutting edge techniques are constantly being improved upon, and the capability to solve unique problems is paramount in real world production. I present a creative project which utilizes novel applications of common techniques, such as projection mapping, multi-tile UV workflows, procedural texture generation, normal mapping, and image based lighting.
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Bayer, Mareike. "Emotion effects in visual language processing." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät II, 2011. http://dx.doi.org/10.18452/16434.
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Emotionale Bedeutung erleichtert die Verarbeitung geschriebener Sprache. Dies zeigt sich sowohl in Verhaltensmaßen als auch in ereigniskorrelierten Potenzialen (EKPs) und resultiert vermutlich aus automatischer Aufmerksamkeitszuweisung auf Grund der hohen intrinsischen Relevanz von emotionalen Reizen. Die vorliegende Arbeit untersucht die Mechanismen von Emotionseffekten in geschriebener Sprache, insbesondere den Zeitverlauf der Emotionseffekte, die Beteiligung des peripheren Nervensystems, sowie die Rolle der Emotionsdimensionen Valenz und Erregung. Emotionseffekte in EKPs beginnen mit einer Latenz von 100 ms nach Stimulusonset. Dies deutet auf die Existenz eines schnellen und automatischen Erkennungssystems für emotionale Wörter hin. Zeitverlauf und Verteilung der Emotionseffekte weisen große Ähnlichkeit zu Befunden für emotionale Bilder auf und lassen auf ein domänenübergreifenden System zur Emotionserkennung schließen. Übereinstimmend mit dieser Annahme zeigen sich weitere Ähnlichkeiten in der Verarbeitung emotionaler Wörter und Bilder in einer Studie, die die Interaktion von stimulusbasierter Aufmerksamkeit und Emotion in der Wortverarbeitung untersuchte. Die Ergebnisse dieser Studie legen auf Grund des arbiträren Charakters von Schriftsprache den Schluss nahe, dass der Verarbeitungsvorteil für emotionale Reize zu einem geringeren Anteil als bisher vermutet auf biologischer Relevanz beruht. Neben diesen Ähnlichkeiten zeigt sich ein domänenspezifischen Unterschied in der Emotionsverarbeitung. Während die Darbietung emotionaler Bilder oft mit erhöhter Aktivierung des autonomen Nervensystems einhergeht, zeigen Befunde zur Pupillenaktivität, dass die Verarbeitung emotionaler Wörter nicht zwangsläufig zu autonomer Aktivierung führen muss; stattdessen scheint der Verarbeitungsvorteil für emotionale Wörter darauf zu beruhen, dass weniger kognitive Ressourcen für deren Verarbeitung notwendig sind.Emotional meaning impacts the processing of written words, leading to facilitated processing that is visible not only in behavioral parameters, but also in event-related potentials (ERPs). It has been suggested that this processing benefit occurs because emotional stimuli involuntarily attract attention, possibly based on their higher intrinsic relevance. The present work investigates the conditions of emotion effects in word recognition, focusing on the time course of emotional processing, on the involvement of autonomic activation, and on contributions of emotional dimensions valence and arousal. In ERPs, emotion effects were evident from approximately 100 ms after stimulus onset, providing evidence for a fast and automatic detection and facilitation of emotional words. The time course and topography of emotion effects is in parallel to findings for affective pictures and suggests the existence of a common system for the extraction of emotional content across stimulus domains. In line with these findings, interactions of stimulus-triggered attention and emotion during word recognition are highly similar to interactions in picture processing. Due to the symbolic nature of words, this finding implies that emotion detection is less dependent on biological relevance than previously assumed. Apart from these analogies, the present results revealed a difference in emotional processing across stimulus domains. While affective pictures have frequently been reported to elicit augmented activity in the autonomic nervous system, evidence from pupillary responses indicates that emotional words do not mandatorily trigger autonomic activation. Instead, the processing advantage visible in behavioral measures seems to result from cognitive facilitation of emotional words.
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Al-Abood, Saleh Ahmed. "Effects of visual demonstrations on motor skill acquisition : a visual perception perspective." Thesis, Manchester Metropolitan University, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340691.
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Wagener, Thomas Dane. "Visual Effects and the Test of Time." Ohio University Honors Tutorial College / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=ouhonors1244204910.
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Limsäter, Fredrik. "REACT - Crowd Simulation System for Visual Effects." Thesis, Linköping University, Department of Science and Technology, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-4737.
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By using existing knowledge from the game community, which have had a long experience from game artificial intelligence, and new research
from the field of artificial intelligence I have implemented REACT, a crowd simulation system for visual effects. REACT is based on high-level behaviour that uses an underlying layer of low-level behaviour. The high-level capabilities gives the digital character means to reasoning about how to achieve certain goals based on a knowledge base of rules and facts that are present in the virtual world. This gives the digital character a degree of autonomous intelligent behaviour.
REACT is designed to integrate directly into the 3D animation package Maya as a plug-in. This means that the animators can continue to animate their characters via their animation package of choice, rather than having to learn a new technology. In addition, many animators are already familiar with the workflow of Maya, so learning curves are reduced.
REACT is already in use in the visual effects industry where it has proven itself to be a worthy competitor to the existing systems on the market.
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Sterner, Johansson Tor. "Applications of Advanced Physics in Visual Effects." Thesis, Umeå universitet, Institutionen för datavetenskap, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-48329.
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AgX Multiphysics is a toolkit for performing physics-based simulations, developed by Algoryx Simulations AB. AgX provides stable physics simulations and is used for industrial and engineering simulations around the world.This thesis examines the possibilities for AgX to be used in the visual effects market for films and commercials. The thesis includes a survey of opinions of professionals from the visual effects company Digital Domain. The three most wanted capabilities from AgX was according to the survey; stiff constraints, fluid-rigid body interaction and hair simulation. Furthermore, all new tools must improve or be equal on all aspects compared to the old tools, and have good scalability.Several simulations were run to compare the stiff constraints and scalability of AgX with the currently used tools. The results show that AgX handles stiff constraints a lot better than the old tool and is also highly scalable.In summary, for saving time from doing tedius tasks and for using physics to an extent earlier not possible, AgX would be a good addition to the current use of physics in visual effects.
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Sharma, Dinkar. "Effects of attention on audio-visual speech." Thesis, University of Reading, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329379.
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Rezec, Amira A. "Effects of attention on visual motion processing /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC IP addresses, 2004. http://wwwlib.umi.com/cr/ucsd/fullcit?p3119178.
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Rabovsky, Milena. "Semantic richness effects in visual word processing." Doctoral thesis, Humboldt-Universität zu Berlin, Lebenswissenschaftliche Fakultät, 2014. http://dx.doi.org/10.18452/17073.
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Lesen zielt darauf ab, Bedeutung aus geschriebenem Text zu extrahieren. Interessanterweise unterscheiden sich Wörter beträchtlich hinsichtlich der Menge mit ihnen assoziierter Bedeutung, und es wurde kürzlich gezeigt, dass eine hohe Bedeutungshaltigkeit lexikalische und semantische Aufgaben erleichtert. Die vorliegende Dissertation kombiniert ereigniskorrelierte Potentiale (EKPs) und konnektionistische Modellierung, um einige offene Fragen zur Rolle der Bedeutungshaltigkeit bei der Wortverarbeitung anzugehen. Hierbei wurden EKPs verwendet, um den Zeitverlauf unabhängiger Einflüsse der Anzahl semantischer Merkmale und Assoziationen beim Wortlesen zu bestimmen sowie Einflüsse von Bedeutungshaltigkeit auf implizites Wortlernen zu untersuchen. Um die zugrundeliegenden Mechanismen besser zu verstehen, wurden die Ergebnisse anschließend mittels eines semantischen Netzwerk-Modells simuliert. Es zeigten sich keine Einflüsse der Anzahl der Assoziationen, aber eine schnelle Aktivierung semantischer Merkmale, die das EKP bereits ab 190 ms beeinflussten - nur 20 bis 30 ms nach und zeitlich überlappend mit der Aktivierung orthographischer Repräsentationen, die durch N1-Lexikalitätseffekte angezeigt wurden. Im weiteren Verlauf ging eine hohe Merkmalsanzahl mit größeren N400-Amplituden einher. Zudem verstärkten semantische Merkmale Wiederholungseinflüsse auf die Akkuratheit lexikalischer Entscheidungen und N400-Amplituden, was einen ersten Hinweis auf Einflüsse von Bedeutungshaltigkeit auf implizites Wortlernen darstellt. Diese Ergebnisse stehen im Einklang mit merkmalsbasierten semantischen Netzwerk-Modellen. Simulationen legen nahe, dass semantische Aktivierung lexikalische Entscheidungen erleichtert, während Netzwerk-Fehler in engem Zusammenhang mit N400-Amplituden stehen. Da Netzwerk-Fehler psychologisch als implizite Vorhersagefehler interpretiert werden, deuten diese Ergebnisse darauf hin, dass N400-Amplituden implizite Vorhersagefehler im semantischen System widerspiegeln.Language ultimately aims to convey meaning. Importantly, the amount of associated semantic information varies considerably between words. Recent evidence suggests that the richness of semantic representations facilitates performance in lexical and semantic tasks, but much remains to be learned about semantic richness effects. The present dissertation combined event-related brain potentials (ERPs) and connectionist modeling to address several unresolved issues concerning the role of semantic richness in word processing. Specifically, ERPs were employed to investigate the time course of independent influences of the number of semantic features and associates during word reading (study 1) and influences of semantic richness on implicit word learning (study 2). Aiming at advancing a mechanistic understanding of the obtained results, both studies were subsequently simulated using a network model of semantic cognition (study 3). Results showed no influences of the number of associates, but fast access to semantic features, with influences of feature-based semantic richness starting at about 190 ms - a mere 20 to 30 ms after and temporally overlapping with the activation of orthographic representations as reflected by N1 lexicality effects. Later on, a high number of semantic features induced larger N400 amplitudes. Furthermore, the number of semantic features enhanced repetition priming effects on lexical decision accuracy and N400 amplitudes, providing initial evidence for influences of semantic richness on implicit word learning. These results are in line with feature-based network models of semantic cognition. Simulations with such a model suggest that semantic activation can facilitate lexical decisions, while network error closely corresponds to N400 amplitudes. In psychological terms, network error has been conceptualized as implicit prediction error. Thus, these results are taken to suggest that N400 amplitudes reflect implicit prediction error in semantic memory.
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Patterson, Michael J. "The effects of visual variables within a complex visual scene on decision processes." Diss., Georgia Institute of Technology, 1985. http://hdl.handle.net/1853/31019.
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Dawkins, Tamara. "A developmental study of visual attention : spatial and temporal effects in visual filtering." Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=99585.
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Because children are bombarded by an abundance of information from the environment, the development of the ability to filter extraneous information in order to attend to the most relevant information is crucial for optimal information processing. The ability to effectively filter affects every aspect of children's functioning, including educational activities and social interactions. In order to assess the development of filtering with ecologically relevant factors, a forced-choice filtering paradigm in which the target and distracting stimuli were presented at different times was used to measure the speed of target identification among a group of 6-year-olds (n=10), 7-year-olds (n=12), 9-year-olds (n=13) and adults (n=13). The targets were presented at the centre of a computer screen with flankers presented to their left and right along the same horizontal plane. The flankers varied with regard to proximity to the target and were presented 200 ms or 400 ms before, at the same time as, or 200 or 400 ms after the presentation of the target. The distance between the distractors and target was also varied to assess the ability of participants to optimally narrow their focus of attention. Temporal differences in the onset of the target and distractors were used to assess issues of attentional control in a real-world context, where attention must be maintained within a changing environment. Though no difference in response time was observed for the presentation of close and far flankers, the display of flankers before the targets led to faster response times in all four groups while the display of flankers after the target led to slower response times in the two youngest groups. The results are consistent with the notion that children are less efficient in their ability to filter attention compared to adults. Findings are discussed in relation to developmental changes from age 6 years to adulthood.
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Ip, Ifan Betina. "Effects of visual attention on stereoscopic depth perception in the human visual cortex." Thesis, University of Oxford, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.543544.
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Johnson, Paul. "Invisibilising the corporeal : exploring concepts of compositing and digital visual effects." Thesis, University of Exeter, 2011. http://hdl.handle.net/10036/4055.
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This thesis seeks to explore the way in which invisibility as a concept becomes explicitly housed within digital compositing, visual effects (VFX) and certain attendant techniques. The chapters will establish how compositing and effects techniques can be seen as pushing modern filmmaking into concealing, and therefore visually releasing, certain physical structures within films’ images and their production. This shall be achieved by drawing upon a combination of texts that disseminate the technical nature and make-up of VFX, alongside discussion and theorisation of their use within cinema, together with other established film theory. I will examine cases of VFX techniques within cinema that can be used to investigate how their construction and utilisation create invisibility to accommodate and nullify the profilmic elements captured through the camera and aspects of technology. The chapters begin by examining how the work of Georges Méliès, whose films use the concept of invisibility to promote a breakdown of temporal and spatial qualities, become redeployed in certain modern digital effects-based films. Expanding on this, the second chapter explores how theories surrounding realism as espoused through mise-en-scène and the so-called physical “truth” of the captured world can be rearticulated through VFX both optical and digital. Chapter three looks at how breaking down the physical structure of a performer through VFX and motion-capture result in characterisations that produce a sense of ghostliness, where the Bazinian mummification of photographic capture has new existence breathed into it. Finally, chapter four explores how recent developments in effects techniques in creating the Invisible Man act as a reflection of the physical body unbound in a digital world. Here, the digital infrastructure of modern culture, such as the Internet, is used to highlight how a more free-flowing and vivacious body can exist and make use of unseen and non-physical practices to commit nefarious acts, such as hacking. It is these aspects that become reflected in the most recent film iteration of the Invisible Man, Hollow Man (2000).
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Kirchner, Holle. "Visual auditory interstimulus contingency effects in saccade programming." [S.l.] : [s.n.], 2001. http://deposit.ddb.de/cgi-bin/dokserv?idn=965164586.
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Marrett, Narisa E. "Effects of ageing on visual attention and perception." Thesis, University of Auckland, 2011. http://hdl.handle.net/2292/7010.
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A bilateral letter version of the spatial cueing technique introduced by Posner (1980) was employed across five experiments. Four experiments also used a perceptual cue discrimination task. In Experiment 1 the effects of ageing on visual attention and perception were examined using a simple version of the paradigm with one valid and one invalid letter (X versus T). Perceptual cue discrimination and visual orienting at both brief (150 ms) and long (500 ms) stimulus onset asynchronies (SOAs) were intact for both age-groups. In Experiment 2 however, when the same tasks were used but with an increase in complexity to four valid and four invalid letters, whilst both groups were able to accurately perform the Perception Task, older adults did not benefit from the cues when performing the Attention Task. Based on research supporting an increase in attentional set-size with categorisation of stimuli, Experiment 3 was conducted using vowels as the valid letters (A E I O). Older adults were able to successfully perform both tasks. This was interesting as the degree of visual/perceptual complexity between Experiment 2 and 3 was similar. In Experiment 4 the nature of participants' awareness of the cue-target contingencies was examined using the Experiment 1 Attention Task, however, implicit instructions were used and a post-experiment questionnaire was administered to probe awareness. Any cue-target learning that occurred in either age group was found to be explicit. In Experiment 5 electrophysiological methods were used to compare performance on the Attention and Perception tasks (using SOAs of zero & 700 ms) to explore further the dorsal/ventral distinction and age-related effects on it. The behavioural data showed strong effects of cue validity and high levels of accuracy for both age-groups as well as slower overall response times for the older adults. P1 amplitudes were greater on validly-cued trials for both groups on the Attention Task but the effect occurred later for younger adults. Within an early time window a strong dorsal/ventral distinction was present for both groups and this was maximal in the parietal lobe in the Attention Task, and in the temporal lobe in the Perception Task, which supported a dual-pathway model of vision.
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Karlsson, Daniel. "En enkel förbättring av stränder inom Visual Effects." Thesis, Högskolan i Gävle, Avdelningen för Industriell utveckling, IT och Samhällsbyggnad, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-14807.
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Om man vill skapa ett realistiskt hav inom Computer Graphics är det viktigt att man har snygga övergångar till andra material. Ett exempel på detta är stränder och det är precis där fokusen på den här studien har legat. Studien gick ut på att hitta en enklare lösning på att visuellt förbättra stränder inom Computer Graphics. För att göra detta så testade två olika metoder i olika experiment. Den ena tekniken som testades var att simulera partiklar för att få fram en bättre strandlinje och de andra var att skapa en shader för att förbättra den. Resultatet var att shadern var det bästa sättet att lösa problemet på medan simuleringen var en lite för komplicerad lösning för det här problemet.
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Edquist, Jessica. "The effects of visual clutter on driving performance." Monash University Accident Research Centre, 2009. http://arrow.monash.edu.au/hdl/1959.1/64951.
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Driving a motor vehicle is a complex activity, and errors in performing the driving task can result in crashes which cause property damage, injuries, and sometimes death. It is important that the road environment supports drivers in safe performance of the driving task. At present, increasing amounts of visual information from sources such as roadside advertising create visual clutter in the road environment. There has been little research on the effect of this visual clutter on driving performance, particularly for vulnerable groups such as novice and older drivers. The present work aims to fill this gap. Literature from a variety of relevant disciplines was surveyed and integrated, and a model of the mechanisms by which visual clutter could affect performance of the driving task was developed. To determine potential sources of clutter, focus groups with drivers were held and two studies involving subjective ratings of visual clutter in photographs and video clips of road environments were carried out. This resulted in a taxonomy of visual clutter in the road environment: ‘situational clutter’, including vehicles and other road users with whom drivers interact; ‘designed clutter’, including road signs, signals, and markings used by traffic authorities to communicate with users; and ‘built clutter’, including roadside development and any signage not originating from a road authority. The taxonomy of visual clutter was tested using the change detection paradigm. Drivers were slower to detect changes in photographs of road scenes with high levels of visual clutter than with low levels, and slower for road scenes including advertising billboards than road scenes without billboards. Finally, the effects of billboard presence and lead vehicles on vehicle control, eye movements and responses to traffic signs and signals were tested using a driving simulator. The number of vehicles included appeared to be insufficient to create situational clutter. However billboards had significant effects on driver speed (slower), ability to follow directions on road signs (slower with more errors), and eye movements (increased amount of time fixating on roadsides at the expense of scanning the road ahead). Older drivers were particularly affected by visual clutter in both the change detection and simulated driving tasks. Results are discussed in terms of implications for future research and for road safety practitioners. Visual clutter can affect driver workload as well as purely visual aspects of the driving task (such as hazard perception and search for road signs). When driver workload is increased past a certain point other driving tasks will also be performed less well (such as speed maintenance). Advertising billboards in particular cause visual distraction, and should be considered at a similar level of potential danger as visual distraction from in-vehicle devices. The consequences of roadside visual clutter are more severe for the growing demographic of older drivers. Currently, road environments do not support drivers (particularly older drivers) as well as they could. Based on the results, guidance is given for road authorities to improve this status when designing and location road signage and approving roadside advertising.
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Irwin, Amy. "Investigating the effects of accent on visual speech." Thesis, University of Nottingham, 2008. http://eprints.nottingham.ac.uk/10614/.
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Speechreading is a complex skill affected by both the observer's method of extracting visual speech information and talker-specific variation in speech production. This thesis focuses upon accent, a factor that can influence both an observer's viewing strategy and talker speechreadability. Auditory research demonstrates that an unfamiliar accent reduces speech intelligibility. The primary aim here was to determine whether accent type, familiarity or variation would alter visual speech intelligibility with consequential effects upon speechreading performance. Experiments 1 and 2 considered visual discrimination of native and non-native accented speech and the influence of non-native accent upon speechreading performance. Results indicated that observers were able to utilise visual cues for discrimination and were significantly poorer at speechreading a non-native accent. Experiments 3, 4 and 5 examined the influence of regional accent on speechreading performance. Results indicated that visual speech performance was significantly worse for Glaswegian-accented talkers than for talkers with a Nottingham accent. However, no clear advantage for accent familiarity was found. Experiment 6 examined the influence of accent type and talker variability upon speechreading performance. Accent type was consistently the dominant influence upon speechreading performance, above familiarity and variation. Experiments 7, 8, 9 and 10 examined the influence of exposure, context and repetition upon the effects of a Glaswegian accent. Here, the effect of the Glaswegian accent on talker speechreadability was reduced by context and repetition, but not removed entirely. In conclusion, while visual accent type mostly determines visual speech intelligibility, accent familiarity mostly determines auditory speech perception. Although spoken accent effects can be quickly reduced through exposure, no such effect was found here in the visual modality. Both context and repetition were necessary to improve the intelligibility of accented speech. This indicates a potential difference in the processing of accented speech across the two modalities and has implications for speechreading training.
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Merlo, James. "CROSS-MODAL EFFECTS IN TACTILE AND VISUAL SIGNALING." Doctoral diss., University of Central Florida, 2008. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/2773.
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Using a wearable tactile display three experiments were conducted in which tactile messages were created emulating five standard US Army and Marine arm and hand signals for the military commands, namely: "Attention", "Halt", "Rally", "Move Out", and "Nuclear Biological or Chemical event (NBC)". Response times and accuracy rates were collected for novices responding to visual and tactile representations of these messages, which were displayed either alone or together in congruent or incongruent combinations. Results indicated synergistic effects for concurrent, congruent message presentations showing superior response times when compared to individual presentations in either modality alone. This effect was mediated by participant strategy. Accuracy similarly improved when both the tactile and visual presentation were concurrently displayed as opposed to separately. In a low workload condition, participants could largely attend to a particular modality, with little interference from competing signals. If participants were not given instructions as to which modality to attend to, participants chose that modality which was received first. Lastly, initial learning and subsequent training of intuitive tactile signals occurred rapidly with large gains in performance in short training periods. These results confirm the promise for tactile messages to augment visual messaging in challenging and stressful environments particularly when visual messaging is maybe preferred but is not always feasible or possible.Ph.D.
Department of Psychology
Sciences
Psychology PhD
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Telling, Anna L. "Semantic and phonological context effects in visual search." Thesis, University of Birmingham, 2008. http://etheses.bham.ac.uk//id/eprint/182/.
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Visual search requires participants to search for a pre-specified target amongst a number of distractors. According to theories of visual search, attention is directed towards the target through a combination of stimulus-driven (bottom-up) and goal-driven (top-down) means. For example, when searching for a red car, top-down attention can prepare the visual system to prioritise items with matching visual properties to the target, e.g., red objects. Theories of visual search support guidance according to visual properties, including the Guided Search model (Wolfe, 1994) and Attentional Engagement Theory (AET: Duncan & Humphreys, 1989). However, whether or not attention can be guided according to non-visual properties of the stimulus, such as semantic and name information, remains controversial (Wolfe & Horowitz, 1994). This thesis studied search for a target (e.g., baseball-bat) in the presence of semantically related (e.g., racquet), phonologically identical (homophones, e.g., animal-bat) and phonologically related distractors (e.g., bag). Participants’ reaction times (RTs), error rates, eye movements and event-related potentials (ERPs) were monitored, and performance compared between young, older adult and brain-damaged individuals. Chapters 2 to 4 report semantic interference for all participant groups; Chapter 5 reports homophone interference in young adults and Chapter 6 reports no interference of phonologically related distractors in search for the target by young adults. The results support search being guided according to semantic and whole-name information about the target only. The mechanisms involved in this interference and contributions of these findings to the theories of visual search will be discussed.
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Berger, Grönros Viktor. "The Effects of Visual Style on Perceived Challenge." Thesis, Malmö universitet, Fakulteten för teknik och samhälle (TS), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:mau:diva-20218.
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With a recent rise in popularity (and controversy) of challenging games, many have attempted to emulate their success. These games are commonly styled with dark, gritty and often surreal settings and characters. Beyond setting the tone, is there a measurable effect from these visual styles on the perception of challenge, and if so, what are those effects? This study looks at similar research and/or the fields visual style, and/or challenge in games to create a game with two distinct styles, from which as a result, a set of categories to better describe a visual style is proposed. The game is then used as an investigation into what to look for when testing for the impact of visual style on perceived challenge.
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McGinnigle, Samantha. "Anterior segment anomalies and effects on visual quality." Thesis, Aston University, 2013. http://publications.aston.ac.uk/20904/.
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The tear film, cornea and lens dictate the refractive power of the eye and the retinal image quality is principally defined by diffraction, whole eye wavefront error, scatter, and chromatic aberration. Diffraction and wave aberration are fundamentally pupil diameter dependent; however scatter can be induced by refractive surgery and in the normal ageing eye becomes an increasingly important factor defining retinal image quality. The component of visual quality most affected by the tear film, refractive surgery and multifocal contact and intraocular lenses is the wave aberration of the eye. This body of work demonstrates the effects of each of these anomalies on the visual quality of the eye. When assessing normal or borderline self-diagnosed dry eye subjects using aberrometry, combining lubricating eye drops and spray does not offer any benefit over individual products. However, subjects perceive a difference in comfort for all interventions after one hour. Total higher order aberrations increase after laser assisted sub-epithelial keratectomy performed using a solid-state laser on myopes, but this causes no significant decrease in contrast sensitivity or increase in glare disability. Mean sensitivity and reliability indices for perimetry were comparable to pre-surgery results. Multifocal contact lenses and intraocular lenses are designed to maximise vision when the patient is binocular, so any evaluation of the eyes individually is confounded by reduced individual visual acuity and visual quality. Different designs of aspheric multifocal contact lenses do not provide the same level of visual quality. Multifocal contact lenses adversely affect mean deviation values for perimetry and this should be considered when screening individuals with multifocal contact or intraocular lenses. Photographic image quality obtained through a multifocal contact or intraocular lens appears to be unchanged. Future work should evaluate the effect of these anomalies in combination; with the aim of providing the best visual quality possible and supplying normative data for screening purposes.
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Robertson, K. A. "The effects of vigabatrin of the visual system." Thesis, Aston University, 2001. http://publications.aston.ac.uk/12254/.
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This thesis considers the visual electrophysiological effects of vigabatrin (an anti-epileptic drug, which acts by increasing the levels of the inhibitory neurotransmitter GABA on the retina of the eye compared to the concentric visual field defects which have been found associated with the drug. Flash and pattern ERG's, EOG's multifocal ERG's (VERIS), flash and pattern VEP's and visual fields were tested. Although VEP's have been shown not to be affected by vigabatrin, these were recorded to complete the testing. Initially, of the eight vigabatrin patients with known visual field defects, 7 showed abnormally delayed 30Hz flicker a-wave latencies, 5 abnormally delayed 30Hz b-wave latencies and 6 abnormally low 30Hz amplitudes. Also 7 showed an abnormally prolonged latency of oscillatory potential 1 (OP1). The two patients taking vigabatrin at the time of testing showed low EOG Arden index values. The VERIS results correlated well with the severity of the visual field defects. Following this finding, eleven healthy subjects received vigabatrin over a 10-day period. No changes were seen in the visual fields, however, the photopic ERG b-wave latency significantly increased (although not to abnormal values). A matched pairs study with eleven vigabatrin, patients and eleven epileptic patients, who had never taken vigabatrin supported the findings of abnormal 30Hz flicker b-wave and OP latencies associated with vigabatrin, again with the VERIS results correlating to the severity of the visual field defect. The abnormal 30Hz flicker and VERIS responses indicate involvement of the cone photoreceptors and the OP's show an effect on the amacrine cells. The ERG increase in the photopic b-wave latency also suggests involvement of the bipolar cells, however, this effect and the reversible effect on the Arden index after cessation of the drug may be unrelated to the visual field defect. To conclude this thesis, a field specific VEP stimulus was developed to assess the retinal function in the peripheral field of paediatric patients. It comprises of a dartboard stimulus with a central 0-5 degree black and white chequered stimulus, a blank 5-30 degree annulus and a 30-60 degree peripheral chequered stimulus. When optimised on four vigabatrin patients it was found that no peripheral response can be evoked with a field loss exceeding 30-35 degrees. Co-operation was found to be successful in children as young as four years old.
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Saenz, Melissa. "Global effects of attention in human visual cortex /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2002. http://wwwlib.umi.com/cr/ucsd/fullcit?p3071014.
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Pourmoghani, Mehdi. "Effects of gloves and visual acuity on dexterity." [Tampa, Fla.] : University of South Florida, 2004. http://purl.fcla.edu/fcla/etd/SFE0000291.
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Thesis (Ph. D.)--University of South Florida, 2004.Includes vita. Abstract has title: Effects of visual acuity and gloves on dexterity. Title from PDF of title page. Document formatted into pages; contains 53 pages. Includes bibliographical references.
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Dai, Mulan. "THE EFFECTS OF VISUAL PROMPT ON PEDESTRIAN SAFETY." OpenSIUC, 2011. https://opensiuc.lib.siu.edu/theses/649.
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Since 2005, pedestrian deaths nationwide had decreased by more than 16 percent, averaging about 200 fewer deaths per year. However, preliminary data collected from the first six months of 2010 show that the decrease had apparently slowed or stopped--seven more pedestrians died in the first six months of 2010 than for the same period in 2009 (Fogel, 2011). Car - pedestrian collisions at crosswalks were serious matters that required continuous research on increasing pedestrian safety at crosswalks. In this paper, although (e.g., Cox, et al., 2010; Houten & Retting, 2001; Huybers, Van Houten, & Malenfant, 2004; Reagan, Sifrit, Compton, Tenebaum, & Van Houten, 2010) have all contributed to the behavior interventions in pedestrian safety, we followed the procedure of earlier research conducted by Crowley-Koch et al. (2011) on the effects of pedestrian prompts on motorist yielding at crosswalks. In addition, this current study extended the previous study by examining the effects of a pedestrian prompt through a wearing of a Bell® Spider flasher over left arm at resting position, on motorist yielding at a controlled crosswalk. Implications and future directions are discussed.
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Halligan, Peter W. "The behavioural assessment of unilateral visual neglect." Thesis, Oxford Brookes University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.328077.
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Saylor, Stephanie A. "CONTEXTUAL EFFECTS ON FINE ORIENTATION DISCRIMINATION TASKS." Miami University / OhioLINK, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=miami1061319633.
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Cowell, Rosemary Alice. "Modelling the effects of damage to perirhinal cortex and ventral visual stream on visual cognition." Thesis, University of Oxford, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.433315.
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Calvert, J. "The role of dopamine in some aspects of visual processing." Thesis, University of Bristol, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.379550.
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Eren, Kanat Selda. "Visual Object Representations: Effects Of Feature Frequency And Similarity." Phd thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613978/index.pdf.
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The effects of feature frequency and similarity on object recognition have been examined through behavioral experiments, and a model of the formation of visual object representations and old/new recognition has been proposed. A number of experiments were conducted to test the hypothesis that frequency and similarity of object features affect the old/new responses to test stimuli in a later recognition task. In the first experiment, when the feature frequencies are controlled, there was a significant increase in the percentage of &ldquoold&rdquo
responses for unstudied objects as the number of frequently repeated features (FRFs) on the object increased. In the second experiment, where all features had equal frequency, similarity of test objects did not affect old/new responses. An evaluation of the models on object recognition and categorization with respect to the experimental results showed that these models can only partially explain experimental results. A comprehensive model for the formation of visual object representations and old/new recognition, called CDZ-VIS, developed on the Convergence-Divergence Zone framework by Damasio (1989), has been proposed. According to this framework, co-occurring object features converge to upper layer units in the hierarchical representation which act as binding units. As more objects are displayed, frequent object features cause grouping of these binding units which converge to upper binding units. The performance of the CDZ-VIS model on the feature frequency and similarity experiments of the present study was shown to be closer to the performance of the human participants, compared to the performance of two models from the categorization literature.
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Boulet, Jason. "The Effects of Delayed Visual Feedback on Postural Dynamics." Thesis, University of Ottawa (Canada), 2010. http://hdl.handle.net/10393/28594.
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We report on experiments and modeling of the interactions between delayed visual feedback and postural control in human quiet stance. A heuristic model is derived based on physiological and psychophysical parameters. The level of agreement found between the data and the model was found to be very good for power spectral densities, probability density functions and mean-squared displacements (or Hurst exponents). The stochastic delayed differential model identifies critical time scales of postural corrections. We also investigate properties of the model such as stability, small delay approximations and the power spectral density. Lastly, we use nonlinear time series techniques to investigate the temporal structure of the experimental postural dynamics. We propose the first dynamical model of visually assisted posture control.
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Ngo, Kam to Frederick. "Visual special effects in a virtual reality training system." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0006/MQ44029.pdf.
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Lichacz, Frederick M. "The focus of length effects in visual word recognition." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape15/PQDD_0005/NQ37047.pdf.
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Nuntasunti, Suchart. "The Effects of Visual-Based Information Logistics in Construction." NCSU, 2004. http://www.lib.ncsu.edu/theses/available/etd-01052004-212738/.
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The construction industry has, for sometime, suffered from stagnant productivity, high accident rate, project delays, and poor quality. Research studies have shown that the major cause of these performance problems is the lack of effective communication. This research was launched to investigate the usefulness of a comprehensive information logistics model on construction process performance. In order to test and validate key components of the model, a prototype network system named Visual-based Integrated Wireless Site (V-IWS) was developed and tested on a mid-size building construction project. The system was designed to allow every project participant access to real-time visual images of the jobsite and share information interactively with each other as well as with a central database through the Internet. It was developed and evaluated for 7 months in 2003. During the same time, the communication channels adopted by the general contractor, R.N. Rouse, and on-site meetings were observed and analyzed. This analysis indicated that most of the information shared among participants of this project could be handled electronically by the V-IWS. It was demonstrated that the V-IWS: a) reduces production waste and non value-added activities such as material delivery time, b) eliminate the need for unnecessary site visits and meetings, c) adds significant value to project participants by automatically creating visual as-built and picture archives, d) provides operational how-to training for crew, and e) increases site safety and security through automated monitoring. The system is scaleable and more network devices can be added as the building grows. While this study proved technical feasibility of the V-IWS, it became evident that trust, collaboration and information sharing among participants were critical success factors. Due to the industry?s traditional low-bid competition and aversion to change, it is crucial to understand how costs and benefits be distributed. Value sharing as well as technology adoption process need to be studied in order to ensure successful implementation of the system.
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Ngo, Kam To Frederick. "Visual special effects in a virtual reality training system." Thesis, McGill University, 1997. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=20510.
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This thesis presents the design and implementations of some visual special effects for a virtual reality training system. The VR training system is being developed for use by the power station maintenance and electrical contractor personnel. In order for the trainee to perform correct and safe ground welding procedures under a variety of situations, visual cues representing those situations are necessary. Since there is a tradeoff between the realism and the interactivity in any real-time VR system, the challenge in implementing special effects in such a system is to develop a relatively realistic model that is also computationally efficient. The effects that are implemented include rain, snow, fog, sparking and explosion, snow accumulation, lightning, and the rotation of a background textured sky. The algorithms for the snow, rain, and sparks are derived from the theory of the particle systems. All special effects were then evaluated to ensure a suitable compromise between realism and interactivity.