This paper will examine and evaluate via computer simulations different methods, both adaptive and non-adaptive, for the feedback control of the color of dyed paper. The objectives are to maintain the paper color at a desired setpoint despite disturbances such as addition of recycled dyed paper (i.e. broke), and to perform color changes as smoothly as possible. The dynamics of a three dye system are multivariable and nonlinear with a significant transport time delay: thus the incentive for adaptive control. Several predictor-based and Dahlin controllers with gain scheduling are designed, tested in simulation, and compared. Adaptive versions using parameters identified with Recursive Least Squares (RLS) are also tested. For practical applications, the non-adaptive Dahlin algorithm with gain scheduling is shown to offer the best performance, together with relative ease of use. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate

This essay is a discussion of two related topics in contemporary aesthetics: the notion of aesthetic sensitivity, and the question of the objectivity of aesthetic judgements. Its point of departure is the work of Frank Sibley on "aesthetic concepts". In Chapter I intuitionism is rejected both as providing an answer to the question, "Are aesthetic judgements objective?" and as providing the basis for an account of aesthetic sensitivity. In Chapter II an account of aesthetic sensitivity based on the seeing-as notion is explored and ultimately abandoned. In Chapter III the issue of objectivity for aesthetic judgements is developed in detail, as turning on the availability of some decision procedure or other for the resolution of disputes. It is argued that relativism, the position that no such decision procedures for aesthetic judgements are available, cannot be adequately defended. An analogy between aesthetic judgement and color attribution emerges as basic to a promising strategy for a defense of aesthetic objectivism. The strategy involves the demand for an articulation of decision procedures relevant to color attribution. The promise of the strategy is defended when it is argued that standard anti-intuitionist criticisms need not undermine it. Finally, the theses and arguments of one relativist, Isabel C. Hungerland, are criticized. Part of her defense of relativism is traced to her acceptance of an analogy between aesthetic judgement and seeing-as. The results of Chapter II, in which the limits of that analogy are exposed, are employed against her. Chapter IV is an outline of a set of decision procedures for color attribution. Color decision procedures involve the selection of a reference group of observers, whose visual experiences are taken to be authoritative. Members of the reference group are selected on the basis of two principles of selection: one which selects statistically normal observers, and one which selects observers of demonstrably higher discriminatory capacity. A system of subsidiary principles, which operates when the two main are at odds in their selections, is illustrated. In Chapter V the plausibility of an aesthetic analogue of the theory of color objectivity developed in Chapter IV is defended against two major objections. The first objection is based on a point of disanalogy between colors and aesthetic features: the V-emergence" of aesthetic features, It is argued, in effect, that this is not a relevant point of disanalogy. The second objection is based on the view that the meanings of terms used to express aesthetic judgements are never twice the same. This view is criticized, and a more plausible one, which does not pose difficulties for the colors/aesthetics analogy, is considered. / Arts, Faculty of / Philosophy, Department of / Graduate

The primary purpose of the present study was to examine the larger issue of color and emotional responses and, within that framework, to explore ways of specifying complex color displays. Several steps were involved in this investigation. First, a total of 80 color displays representing five levels of hue, two levels of value, two levels of chroma and four levels of motif were constructed. These were unique in that they accurately and systematically sampled the Munsell color space, and in the fact that they contained large numbers of color elements which were colorimetrically specifiable and which at the same time were arranged in such a way that they resembled color pictures. They thus bridged the gap between stimuli used in single color experiments which could be colorimetrically specified, and experiments with unspecifiable color pictures. Secondly, an emotional response measure employing the three dimensions of pleasure, arousal and dominance, was used to assess the effects of the display dimensions of hue, value, chroma and motif and the subject variable of sex. In addition, a verbal measure of information rate was used to assess the extent to which the display motifs influenced subjects' non-affective (i.e., cognitive responses), and subjects' ability to recognize the display motifs was assessed as well. Thirdly, the problem of stimulus specification was approached through the application of a three-step procedure involving increasing stimulus specificity. These approaches dealt with the specification in terms of (1) the individual color elements making up a display, (2) the quantity of these individual color components, and (3) the distribution or location of these elements across the display surface. The latter specification scheme, which was termed "distribution specification", made use of 24 procedures—some based on accepted artistic views and others of a more abstract nature—for calculating the relationship between the color elements in the displays. The measures which these procedures resulted in were subseqently assessed against subjects' responses on the dimensions of pleasure, arousal, dominance and information rate. Initially, a pilot study with 20 subjects and 16 of the 80 displays was conducted to test the general performance of the response measures and to test whether the displays could be presented in the form of projected slides. The results of this study showed that the general experimental procedure was acceptable but that the projection technique distorted the colors of the displays excessively. Based on the conclusions of the pilot study, a larger study using 82 subjects and the displays as originally constructed was conducted. The results were surprising to the extent that complex color stimuli did not differevery substantially from those elicited by single color stimuli: the color dimension of value influenced the emotional responses to the greatest extent, chroma to a somewhat lesser extent, and hue very little. The motif of the displays, on the other hand, was found to make a substantial difference to the way subjects felt about a display, and the way they assessed it in terms of information rate. Also, it was found that the verbal measure of information rate was a good predictor of how well subjects would recognize a motif. The results of the analysis of stimulus specification in terms of the 24 distribution measures was particularly interesting and gratifying in that several of the measures emerged as strong predictors of responses to the emotional measures and information rate. In particular, the artistically common-sense notions of top-bottom and left-right pictorial balance were prominent, as was the specially constructed measure of contrasts within small sampling areas of the displays. It was concluded, first, that the study had reinforced the findings of many past studies dealing with color and affect, and that it had thrown some new light on some of the controversial and contradictory findings of the past. Secondly, the study had moved the investigation of emotional responses to color pictures and works of art a substantial step closer to realization. Finally, the study had suggested new and promising avenues to follow in the further investigation of colorimetric specification of complex color stimuli. / Graduate and Postdoctoral Studies / Interdisciplinary - Psychology, Education, Architecture / Graduate

Orientador: Marcio Donato Périgo / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Artes / Made available in DSpace on 2018-08-27T01:56:43Z (GMT). No. of bitstreams: 1 Guimaraes_RodrigoSoares_M.pdf: 24129766 bytes, checksum: d5097a7c5b966caf13dad19ab4d9798e (MD5) Previous issue date: 2015 / Resumo: Todos sabemos que é difícil tentar expressar num discurso verbal o que é arte. Quando indagado sobre esse mesmo dilema, o músico contemporâneo Frank Zappa (1940-1993) afirmou que "escrever sobre música é como dançar sobre arquitetura". Ainda assim, gostaria de arriscar essa empreitada com a intensão de explicitar parte de meu processo de construção das imagens, principalmente as que foram realizadas durante essa investigação sobre os cadernos de desenho. A construção de tais cadernos impõe um processo de reflexão específico, ligado aos meios expressivos que permitem uma aproximação mais adequada com a imposição determinada pelas configurações técnicas de formatos e suportes que os cadernos de desenho impõem, tanto na sua confecção, como no manuseio e, até mesmo, nas formas de expor. Visando expressar-me textualmente da forma mais racional, clara e sistemática possível sobre minha própria produção, dentro da perspectiva de um olhar pautado pela poética visual proposta, decidi organizar esse olhar, essa reflexão por meio da seleção, apresentação e análise de sete cadernos separados em capítulos distintos. Eles evidenciam eixos comuns importantes, como as questões afetivas que direcionam e moldam a construção das imagens, as escolhas cromáticas carregadas de informações visuais ou assumindo uma postura de franca vocação documental, como a proposta praticada há muito pelos artistas viajantes, acadêmicos ou contemporâneos. A confecção ritualizada dos cadernos, prevê posturas diversas em várias etapas do trabalho, da escolha dos materiais, procedimentos técnicos, tomada de decisões, direcionamento do olhar, da memória ou de experimentações mais livres, até a sua completa finalização / Abstract: We all know that it is difficult to try to express a verbal discourse what is art. When asked about this same dilemma, the contemporary musician Frank Zappa (1940-1993) said that "writing about music is like dancing about architecture." Still, I would risk this venture with the intention of explaining part of my images of the construction process, especially those carried out during the investigation into the sketchbooks. The construction of such notebooks impose a particular reflection process on the expressive means to a more appropriate approach to the imposition determined by technical configurations of formats and supports the sketchbooks impose both in its making, as the handling and, even in the forms of display. In order to express myself literally the most rational, clear and systematic as possible on my own production, from the perspective of a look marked by poetic visual proposal, decided to organize this look, this reflection through the selection, presentation and analysis of seven separate notebooks in separate sections. They show important common axes as affective issues that drive and shape the construction of images, loaded chromatic choices of visual information or assuming an attitude of frank documentary vocation, as the proposal practiced long by artists travelers, students or contemporary. The ritualized manufacture of notebooks, provides for various positions in various stages of work, the choice of materials, technical procedures, decision-making, direction of gaze, memory or more free trials until its full completion / Mestrado / Artes Visuais / Mestre em Artes Visuais

Previous attempts to adequately evaluate orientation-specific colored aftereffects (Mccollough Effects) have thus far been unsuccessful in yielding quantitative measures of relative strengths of the effects. Similarly, little success has been shown in previous attempts to establish what level of illumination is necessary in order to evoke the aftereffects. The present study sought to determine (a) whether threshold measurements could serve as adequate, quantitative dependent variables of the Mccollough Effects, (b) whether photopic illumination was necessary in order to evoke the aftereffect. It was predicted that the greater the number of inspection trials, the dimmer the illumination level could be in order for the aftereffects to first be detected. In addition, it was· predicted that the appearance of the test pattern would change markedly near the rod-cone break. The strength of the McCollough Effects, as a function of the number of inspection trials, was examined on subsequent scotopic and photopic threshold measurements in normal color-visioned subjects. All subjects were measured alternately on 10 ascending and 10 descending trials at specific times after being conditioned in "short" (15 min) and "long" (30 min) inspection trials, counterbalanced across subjects, with a 7-day interval between test trials. Overall, statistically insignificant results were achieved for both predictions; possible explanation of the results and changes in experimental design were discussed.

The McCollough Effect is an orientation specific colored aftereffect. That is, following prolonged viewing of a vertical grid on orange ground alternated with a horizontal grid on blue ground, a yellow-orange hue is perceived on an achromatic horizontal grid, and a bluish hue on a vertical grid. McCollough suggested that the colored aftereffect may depend upon color adaptation of a population of neural elements specific to colored edges of a particular orientation. Accordingly vertical edge detectors sensitive to orange adapt during inspection such that when vertical edges are presented on an achromatic ground only those non-adapted color-line detectors respond creating the perception of blue. Similarly, horizontal edge detectors specific to blue adapt such that response to achromatic edges creates the perception of yellow-orange. In a subsequent study McCollough and Clark used left and right diagonal inspection patterns and observed that the aftereffect of orange and right diagonal was influenced by the left diagonal color that was alternated with it. The aftereffect of orange right diagonal tended toward blue when the orange stimulus was alternated with a blue left diagonal stimulus pattern and tended toward green when the orange stimulus was alternated with a green left diagonal pattern. On the basis of the color coded edge detector theory McCollough and Clark suggested the effect was induced by wavelength adaptation of wavelength sensitive edge detectors which may influence the hue of the• aftereffect on the orthogonal test pattern. A test of McCollough's model of color coded edge detectors was made by presenting a colored field (no lines) to S before the presentation of the color-line stimulus. If wavelength and edge stimuli were processed by a population of neural elements sensitive to both, then the aftereffect would not be affected by the presentation of an unlined color field. If color and line stimuli were processed separately, then the "effective" color component of the lined stimulus pattern would be that portion of the spectrum not stimulated by the preceeding color field. The color of the aftereffect would be approximately complementary to the non-adapted population of color receptors stimulated by the lined inspection pattern. In the experiment 28 college juniors observed two inspection conditions. In condition 1 orange vertical alternated with blue horizontal and the aftereffect created was measured via a colorimeter. The same stimulus patterns were employed in condition 2 where each was preceeded by a plain color field that stimulated a portion of the spectrum illuminated by the following lined stimulus. The aftereffect observed was compared with the aftereffect on condition 1. Color matches were measured by three photometer readings indicating percent transmittance of red, blue, and green in each match. These readings were translated into CIE x, y coordinates and the means plotted on a chromaticity diagram. Statistical analysis of the data indicated that the color matches in condition I and condition 2 were significantly different and varied as predicted. While McCollough and Clark attributed the variation in the hue of the colored aftereffect to the relative spectral properties of the lined inspection patterns employed in their experiment, the present study shows that the results may be due to the state of color adaptation resulting from the preceeding stimulus pattern. The adapting color stimulus is not necessarily a lined color pattern. It may indeed be a plain color field. The results suggest that the colored line-contingent aftereffect is created by at least two levels in the visual system: color receptors independent of slope analysers. The color coded edge detector model is not adequate to account for the McCollough Effect.

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