Computing Volumes and Convex Hulls: Variations and Extensions

Geometric techniques are frequently utilized to analyze and reason about multi-dimensional data. When confronted with large quantities of such data, simplifying geometric statistics or summaries are often a necessary first step. In this thesis, we make contributions to two such fundamental concepts of computational geometry: Klee's Measure and Convex Hulls. The former is concerned with computing the total volume occupied by a set of overlapping rectangular boxes in d-dimensional space, while the latter is concerned with identifying extreme vertices in a multi-dimensional set of points. Both problems are frequently used to analyze optimal solutions to multi-objective optimization problems: a variant of Klee's problem called the Hypervolume Indicator gives a quantitative measure for the quality of a discrete Pareto Optimal set, while the Convex Hull represents the subset of solutions that are optimal with respect to at least one linear optimization function.In the first part of the thesis, we investigate several practical and natural variations of Klee's Measure Problem. We develop a specialized algorithm for a specific case of Klee's problem called the “grounded” case, which also solves the Hypervolume Indicator problem faster than any earlier solution for certain dimensions. Next, we extend Klee's problem to an uncertainty setting where the existence of the input boxes are defined probabilistically, and study computing the expectation of the volume. Additionally, we develop efficient algorithms for a discrete version of the problem, where the volume of a box is redefined to be the cardinality of its overlap with a given point set.The second part of the thesis investigates the convex hull problem on uncertain input. To this extent, we examine two probabilistic uncertainty models for point sets. The first model incorporates uncertainty in the existence of the input points. The second model extends the first one by incorporating locational uncertainty. For both models, we study the problem of computing the probability that a given point is contained in the convex hull of the uncertain points. We also consider the problem of finding the most likely convex hull, i.e., the mode of the convex hull random variable

On the Simultaneous Perception of Sound and Three-Dimensional Objects

Although examples of work investigating the perceptual relationship and possibilities of sound and image are common, relatively litle work has been carried out into multimedia works combining sound and three-dimensional objects. A practice-based investigation into this subject is presented with original artworks and contectual material from sound art, sculpture, moving image and psychology. The project sets out to more examine the perception of multimedia work, specifically through the creation and analysis of artworks combining sound and physical objects. It considers three main areas of study: sound’s ability to draw attention to, or modify, the existing properties of an object; techniques which encourage sound and object to appear cohesively as part of the same work; and a discussion of cognitive effects that may occur as a result of their simulataneous perception. Using the concept of the search space from evolutionary computing as an example, the case is made that multimedia artworksde can present a larger field of creative opportunity than single-media works, due to the enhanced interplay between the two media and the viewer's a priori knowledge. The roles of balance, dynamism and interactivity in multimedia work are also explored. Throughout the thesis examples of original artworks are given which exemplify the issues raised. The main outcome of the study is a proposed framework for categorising and analysing the perception of multimedia artworks, based on increasing semantic separation between the sensory elements. It is claimed that as the relationship between these elements becomes less obvious, more work is demanded of the viewer's imagination in trying to reconcile the gap, leading to active engagement and the possibility of extra imaginary forms which do not exist in the original material. It is proposed that the framework and ideas in this document will be applicable beyond the sound/object focus of this study, and it is hoped they will inform research into multimedia work in other forms

Painterly interfaces for audiovisual performance

Thesis (S.M.)--Massachusetts Institute of Technology, Program in Media Arts & Sciences, 2000.Includes bibliographical references (p. 145-149).This thesis presents a new computer interface metaphor for the real-time and simultaneous performance of dynamic imagery and sound. This metaphor is based on the idea of an inexhaustible, infinitely variable, time-based, audiovisual "substance" which can be gesturally created, deposited, manipulated and deleted in a free-form, non-diagrammatic image space. The interface metaphor is exemplified by five interactive audiovisual synthesis systems whose visual and aural dimensions are deeply plastic, commensurately malleable, and tightly connected by perceptually- motivated mappings. The principles, patterns and challenges which structured the design of these five software systems are extracted and discussed, after which the expressive capacities of the five systems are compared and evaluated.Golan Levin.S.M

Design Ideation: The Conceptual Sketch in a Digital Design Culture

Design ideation, or the generating and developing of design ideas is central to designing in both education and practice. But what is the impact of digital technology on conceptual tools, notably the traditional pen and paper sketch? Initial research, in the Introduction highlights how freehand drawing is under pressure from digital technology both in design schools and industry yet educators and practitioners alike seem uncertain how best to deal with the digital challenge. The Literature review, in which the investigation is likened to a sprawling rhizome, covers both practical and philosophical concerns about conceptual tools thereby extending the notion of sketching beyond pen and paper, to what is called sketcherly ways of designing. To find out how to capture designers' use of conceptual tools, the spectrum of Design methodology was explored in which the case study method combined with protocol study emerged as the research strategy to be tested in a Pilot study. The pilot outcome set the scene for a protocol study with first-year design students which, through a series of Ideation workshops, illuminates how sketching together with verbalisation is a powerful combination for conceptualisation. In this, the workshop format emerged as an effective means for encouraging novice designers to develop ideation skills. The pilot was also instrumental for conducting a Multiple case study comprising five second year design students and five recent design graduates working in industry in the domains of fashion, architecture, graphics, product and general design. Using self-reporting and interviews the cases illuminate real uses of conceptual tools situated in everyday designing that reveal the multifaceted yet unpredictable character of ideation. The Summary and Conclusion discuss the future role of the conceptual sketch in digital design environments and suggest how scholarship in the context of teaching and learning design can bridge the worlds of design schools and professional practice. In this, computer-aided ideation, CAI, emerged as a promising research field

The intelligence of seeing : an enquiry into the relationships between perception theory, communication theory and the practice and teaching of drawing

The aim of this research is to develop a method of teaching drawing that empowers fine art undergraduates' practice by broadening their awareness of the inter-relationships between ways of seeing, social belief-systems, and ways of drawing. The domain of drawing is explored via a synthesis of perception and communication theories. This combination is mapped as a matrix integrating the social functions of drawing with the systems of semiotic choices and levels of perception which facilitate students to realise meaning in drawings, and which facilitate viewers to negotiate meaning from existing drawings. The matrix builds on, and develops, existing material in the field of systemic-functional semiotics. Within the parameters of a constructivist paradigm of research, a new drawing-teaching programme is designed, tested over a period of two academic years, and evaluated using the recognised criteria of authenticity proposed by Egon Guba and Yvonna Lincoln. Two classes of data are collected and analysed. Primarily, those gathered using Rensis Likert's method, which elicits group attitudes, indicate positive shifts in the student groups' attitudes to ontological constructs concerning relationships between perception, communication and drawing. Secondly, students' drawings, analysed using the systemic-functional semiotic matrix, provide visual evidence of an expansion in the range of ontological constructs. Analysis of the data demonstrates the validity of the hypothesis: that a drawing-teaching programme based on a synthesis of perception and communication theories may expand students' awareness and understanding of a range of constructions of reality, which ultimately may empower their drawing practice

Artefacts, Technicity and Humanisation industrial design and the problem of anoetic technologies

This thesis concerns the intellectual heritage and autonomy of West European and American industrial design as a discourse community at a moment when biotechnological developments are challenging the certainty of what it means to be human. Proceeding from the assumption that industrial design is an autonomous intellectual engagement played out through the interpretation of technology as an artefact, the thesis identifies how this is a critical moment for industrial designers, who appear to be unable to respond to a problem of the apparent disconnection and the progressive displacement of the human in reference to technology. The thesis identifies the cause of this as the understanding of the artefact, which has conventionally been placed at the centre of its analysis. The way that this has been constructed has not only impacted on design solutions but has led to a particular understanding of technology. It is this understanding of the artefact that has ceased to be sustainable and has precipitated the crisis. The thesis argues that, by revisiting the artefact as a mutable consequence of culture, it is possible to relieve the problem by opening up the scope for finding new methodological approaches. These can be used to develop design strategies that are sufficiently subtle and coherent in their terms to engage with the open complexity of future discussions of the distributed and enacted human

Landscapes of ephemeral embrace : a painter's exploration of immersive virtual space as a medium for transforming perception

The following text has been written to illuminate the research embodied In Ephemere, a fullyimmersive virtual environment which integrates stereoscopic 3D computer-generated images and spatialized 3D sound, with a user interface based on breathing, balance, and gaze. This artwork was begun when I entered the doctoral program at CAiNA (Centre of Advanced Inquiry Into the Interactive Arts) in 1997, and was completed in 1998. The work Ephemere is grounded in a very personal vision, developed over more than 25 years of artistic practice, including, most significantly, painting. Ephemere follows on its predecessor Osmose, and as such, Is a continuation of my efforts to: (I) explore and communicate my sensibility of what it means to be embodied, here now, in the living Rowing world; and (ii) use the medium of immersive virtual space to do so, necessarily subverting its culturally-biased conventions to achieve this goal. The contents of this text are most clearly indicated by its title: Landscapes of Ephemeral Embrace: A Painter's Exploration of the Medium of Immersive Virtual Space for Transforming Perception. And further, by its chapter headings: (I) Context: Rethinking Technology in the "Reign of King Logos ; (II) Defining Terms: Key Concepts and Concerns in the Work; (III) Origins of the Work in Prior Artistic Practice: Emergence of Key Concerns and Strategies; (IV) First Explorations in Immersive Virtual Space: Osmose; (V) Continuing Explorations In Immersive Virtual Space: Ephemere; and (VI) Strategies and Their Implications In the Immersive Experience. In this text, I have focused my discussion on artistic Intent, rather than on whether I have been successful, for this can only be evaluated with the passing of time

The Myth of Égalité: On the Perils of Inclusion for the Special School as Transformative Space

In the present era of inclusion, special schools increasingly serve as spaces for the delivery of supplementary education and rehabilitation services for mainstreamed disabled children. A history of segregation and institutionalization weigh heavily on the sector, prompting many special educators to advocate for students' continued mainstreaming (often against students' wishes) through mastery of the necessary compensatory techniques and technologies that promise to help them attain equality with their non-disabled peers in mainstream schools. Drawing on 14 months of ethnographic research, including bi-weekly in-person participant observation and semi-structured interviews with educators and parents, in a public special school for the blind and visually impaired in southern France, this dissertation explores the narratives and practices that maintain educators in a deficit mindset vis-à-vis disabled lives, a mindset from which it becomes difficult to see the potential of visual impairment to contribute to an enacted, non-representational epistemology in an education system based on ocular-centric objectivism. Nevertheless, students harness being together disabled at the school to make sense of the world through their unique phenomenologies in which sight often plays a surprisingly important part. Engaging anthropology, embodied cognitive science, and critical disability studies, I argue that sight shows up for the children as a tool of playful curiosity for learning in an always emergent present, a disposition I call "sight as question" that stands in contrast to the objectivist "sight as power" standard in mainstream schools. In re-conceptualizing the special school as understated space of embodied knowledge creation, my dissertation makes three primary contributions. First, I show how the French state's race to mainstream all students has exacerbated reactionary approaches to educating disabled children, a reality now hidden behind an innovative facade of assistive technology. Second, I document how such situation continues with the full compliance of otherwise progressive-minded educators because of a historical cultural context wherein national public education is instilled with the status of meritocratic authority responsible for vetting all children for epistemic conformity as a matter of égalité. Finally, I offer an alternative perspective for repurposing special schools to spaces of phenomenological potential led by members of the disabled community and explore what, as such, they might contribute to teaching and learning in an age of artificial intelligence