Structural attributes contributing to locomotor performance in the ostrich

As the fastest long-endurance runner, the bipedal ostrich (Struthio camelus) was selected as a prime model organism to investigate the physical attributes underlying this advanced locomotor performance. A specific integrative approach combining morphological, morphometric, kinematic and pedobarographic methods was developed. The comparative morphometric analysis of the hind limbs of all ratite species revealed that leg segment ratios in the ostrich are the most specialised for efficient locomotion, especially when taking into consideration its unique supra-jointed toe posture. In addition, the crural muscle mass is more concentrated towards the hip joint in the ostrich than in its ratite relatives. According to the Law of the Pendulum, this concentration of mass towards the pivot point – in concert with the relatively longest and lightest distal leg elements – represents a mechanical optimisation of limb swinging capacities. While musculature clearly drives limb movement, the passive guidance and constraint of motion range by ligamentous structures combined with joint surface contours allows a high level of energy output efficiency during all stages of locomotion and ensures articular stability during slow locomotion as well as high-speed performance. So far, the influence of these passive effects in locomotion has been largely ignored. In order to quantify the guiding effect of these anatomical structures, kinematic data of adult ostriches during walking and running were collected. Subsequently, these data were compared with results from manual manipulation experiments performed with the limbs of anatomical specimens – both fully intact and with muscles removed – leaving only the ligament system intact. This investigation revealed that the range of motion among leg segments was nearly identical in all sample groups, especially in regard to maximum extension values. This indicates that ostrich hind limb dynamics are managed to a significant degree by passive elements that ensure a controlled swing-plane with minimal deviation from an optimal attitude. Further dissections allowed some of these features to be described in detail, with an emphasis on functional-morphological examination of the intertarsal joint. The intertarsal joint contains a significant locking mechanism, briefly mentioned in historical documents, but described and functionally analysed herein for the first time. The functional examination qualified the interplay of three collateral ligaments, the tendinous M. fibularis brevis and specific joint surface protrusions as the basis for this effect which remains absent in smaller ground-dwelling bird species. A proximate quantification, based on comparative morphological and kinematic data, revealed function of Struthio's passively locked intertarsal joint as a potent stabiliser in the supporting limb during the ground-contact phase of locomotion. During stance phase, it is crucial that the supporting limb is stabilised internally and in relation to the substrate. As yet, no study exists concerning use and loading of the actual ground contact elements. The toes must absorb body mass, guarantee stable grip and provide energetic push off. Obvious specialisations of the ostrich's phalangeal complex include toe reduction (leaving only 3rd and 4th toe), claw reduction (only at 3rd toe) and a permanently elevated metatarsophalangeal joint. Using a relatively new methodology to examine in vivo toe function, pedobarography was employed on specifically trained ostriches to allow extensive collection of Centre of Pressure (CoP) and load distribution (LD) data. In contrast to a relatively predictable CoP trajectory at all speeds, conspicuous LD differences were observed between slow and fast trials. Load was distributed rather inconsistently during walking, while a typical tripod-like toe-print occurred in all running trials to presumably deliver additional stability during the comparatively short stance phase. Significant grip is provided by the highly directed impact of the 3rd toe claw-tip, suggesting its important function as a positional anchor during running. Pedobarographic analysis further showed the importance of the 4th toe as an outrigger to maintain balance, rendering a future reduction highly unlikely. In conclusion, the application of interdisciplinary methodologies allowed comprehensive data collection and integration of the model organism within its ecological context. The data gained from this thesis increases the current knowledge about ostrich locomotion by identifying distinct structural attributes as essential elements for extreme cursorial performance. The present data may alter existing models for calculation of the metabolic cost of terrestrial locomotion and aid in the reconstruction of theropod locomotion, as these branch sciences often overlook the important role of ligaments and passively-coupled motion cycles in reducing the cost of locomotion

UNSTABLE TERRITORIES OF REPRESENTATION: Architectural Experience and the Behaviour of Forms, Spaces and the Collective Dynamic Environment

This thesis applies an interdisciplinary cybernetic and phenomenological analysis to contemporary theories of representation and interpretation of architecture, resulting in a speculative theoretical model of architectural experience as a behavioural system. The methodological model adopted for this research defines the main structure of the thesis where the narrative and the contributing parts of its complexity emerge. The narrative is presented through objectives and hypotheses that shift and slide between architectural representation and its experience based on three key internal components in architecture: the architectural forms and spaces, the active observers that interact with their environment, and finally, the responsive environment. Three interrelated research questions are considered. The first seeks to define the influence of the theoretical instability between complex life processes, emerging technologies and active perception upon architecture. The second questions the way in which the architectural experience is generated. The third asks: Does architecture behave? And if so, is it possible to define its behavioural characteristics related to its representation, experience and the medium of communication in-between? The thesis begins by exploring the effect of developments in digitally interactive, biological, and hybrid technologies on representation in architecture. An account of architectural examples considers the shift in the meaning of representation in architecture from the actual and literal to the more conceptual and experimental, from the individual human body and its relations to the multifaceted ecosystem of collective and connected cultures. The writings of Kester Rattenbury, Neil Leach, and Peter Cook among others contribute to the transformation of the ordinary perceptual experience of architecture, the development of experimental practices in architectural theory, and the dynamism of our perception. The thesis goes on to suggest that instability in architectural representation does not only depend on the internal components of the architectural system but also on the principles and processes of complex systems as well as changes in active perception and our consciousness that act as the external influences on the system. Established theoretical endeavours in biology of D’Arcy Thompson, Alan Turing, and John Holland and philosophies of Merleau-Ponty, Richard Gregory, and Deleuze and Guattari are discussed in this context. Pre-programmed and computational models, illustrative and generative, are presented throughout the thesis. In the final stage of the development of the thesis architecture is analysed as a system. This is not an unprecedented notion, however defining the main elements and components of this system and their interactions and thereafter identifying that the system behaves and defining its behavioural characteristics, adds to the knowledge in the field of theoretical and experimental architecture. This thesis considers the behavioural characteristics of architecture to be derived from the hypothetical links and unstable thresholds of its non-dualistic notions of materiality and immateriality, reality and virtuality, and finally, intentionality and interpretation

Entwicklung und Analyse neuer flexibler Fluidaktoren und Realisierung nachgiebiger Leichtbau- Robotersysteme

Mit der Tatsache, dass die Grenzen zwischen Mensch und Maschine immer enger gezogen werden, sind besondere Anforderungen an die Antriebstechnologie und Maschinenkonzeption verbunden. Besonders die sichere Kooperation zwischen Mensch und Roboter fordert von Maschinenseite Nachgiebigkeit und Adaptivität in Verbindung mit geringen beschleunigten Massen. Die vorliegende Arbeit entwickelt das Antriebsprinzip flexibler Fluidaktoren weiter und erschliesst es einem breiten Anwendungsspektrum

The Machine as Art/ The Machine as Artist

The articles collected in this volume from the two companion Arts Special Issues, “The Machine as Art (in the 20th Century)” and “The Machine as Artist (in the 21st Century)”, represent a unique scholarly resource: analyses by artists, scientists, and engineers, as well as art historians, covering not only the current (and astounding) rapprochement between art and technology but also the vital post-World War II period that has led up to it; this collection is also distinguished by several of the contributors being prominent individuals within their own fields, or as artists who have actually participated in the still unfolding events with which it is concerne