864 research outputs found

    THE REALISM OF ALGORITHMIC HUMAN FIGURES A Study of Selected Examples 1964 to 2001

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    It is more than forty years since the first wireframe images of the Boeing Man revealed a stylized hu-man pilot in a simulated pilot's cabin. Since then, it has almost become standard to include scenes in Hollywood movies which incorporate virtual human actors. A trait particularly recognizable in the games industry world-wide is the eagerness to render athletic muscular young men, and young women with hour-glass body-shapes, to traverse dangerous cyberworlds as invincible heroic figures. Tremendous efforts in algorithmic modeling, animation and rendering are spent to produce a realistic and believable appearance of these algorithmic humans. This thesis develops two main strands of research by the interpreting a selection of examples. Firstly, in the computer graphics context, over the forty years, it documents the development of the creation of the naturalistic appearance of images (usually called photorealism ). In particular, it de-scribes and reviews the impact of key algorithms in the course of the journey of the algorithmic human figures towards realism . Secondly, taking a historical perspective, this work provides an analysis of computer graphics in relation to the concept of realism. A comparison of realistic images of human figures throughout history with their algorithmically-generated counterparts allows us to see that computer graphics has both learned from previous and contemporary art movements such as photorealism but also taken out-of-context elements, symbols and properties from these art movements with a questionable naivety. Therefore, this work also offers a critique of the justification of the use of their typical conceptualization in computer graphics. Although the astounding technical achievements in the field of algorithmically-generated human figures are paralleled by an equally astounding disregard for the history of visual culture, from the beginning 1964 till the breakthrough 2001, in the period of the digital information processing machine, a new approach has emerged to meet the apparently incessant desire of humans to create artificial counterparts of themselves. Conversely, the theories of traditional realism have to be extended to include new problems that those active algorithmic human figures present

    Development and evaluation of custom prosthetic devices for a companion animal utilizing additive manufacturing.

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    BACKGROUND AND SIGINIFICANCE: Few options exist for companion animals in need of prosthetic devices. With the rise of rapid prototyping technology, the availability and customization of prosthetic devices for individual companion animals is now a viable and cost effective alternative to the current options of a peg leg prosthetic, or wheel-assisted prosthetic device. The goals of this study were to describe the (1) specific needs and (2) biomechanics of a feline with bilateral thoracic limb amputation, (3) develop custom prosthetic devices utilizing rapid prototyping technology, and (4) describe the biomechanics of a feline with bilateral thoracic limb amputation using the custom prosthetic devices. The feline being studied in this project is a 2 year old Maine Coon feline weighing 9 lbs. She was a stray that was found with severe frostbite on her thoracic limbs. These sections of her thoracic limbs were amputated to remove the necrotic tissue. SPECIFIC AIMS: The goals of this study is to describe the (1) specific needs and (2) biomechanics of feline with bilateral thoracic limb amputation, (3) develop custom prosthetic devices utilizing rapid prototyping technology, and (4) describe the biomechanics of a feline with bilateral thoracic limb amputation with the use of the custom prosthetic devices. MATERIALS & METHODS: Fused Deposition Modeling (FDM) technology was utilized to fabricate the prosthetic devices that were designed and put through a Finite Element Analysis to simulate static loading and fatigue testing during various stages of the gait cycle. The devices were mechanically tested to ensure device failure did not occur during static loading, as well as fatigue tested to resemble continued use. vii Kinematic gait analysis was performed prior to and after use of the prosthetic devices, and outcomes were compared between the scenarios. Gait data was also compared to published feline gait data to determine any effects to the feline’s gait resulting from the amputation, and if this effect was corrected through the use of the prosthetic devices. RESULTS: FDM was a cost effective way to fabricate strong, durable prosthetic devices designed specifically for a companion animal with dual thoracic limb amputation. Mechanical testing ensured that the prosthetic devices can survive over 10,000 loading cycles at 6 N, and 3000 N of vertical force. The gait analysis performed without the use of the prosthetic devices show increased flexion of the elbows, stifle, and tarsus joint during ambulation. Gait analysis during the use of the prosthetic devices removes this additional flexion. CONCLUSION: Use of prosthetic devices can have a positive influence in the gait of companion animals with amputations. The comparison between the two data sets shows removal of the additional flexion found in the thoracic limbs when the prosthetic devices are used. This project showcases the feasibility of using additive manufacturing to create cost effect and durable prosthetic devices for use in companion animals

    Compliant contact force models in multibody dynamics : evolution of the Hertz contact theory

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    Over the last decades, several compliant contact force models have been proposed. However, no complete and systematic comparison has been done on these models, which provides information on their range of application and accuracy for use in different contact scenarios. Thus, the selection of an appropriate model for a given contact problem is still an important and challenging issue to be addressed. The Hertzian contact theory remains the foundation for almost all of the available force models, but by itself, it is not appropriate for most impacts in practice, due to the amount of energy dissipated during the impact. A good number of contact force models have been offered that augment the Hertzian law with a damping term to accommodate the energy loss during the impact process for small or moderate impact velocities. In this work, the main issues associated with the most common compliant contact force models of this type are analyzed. Results in terms of the dynamic simulations of multibody systems are presented, which allow for the comparison of the similarities and differences among the models considered.Fundação para a Ciência e a Tecnologia (FCT) - DACHOR - Multibody Dynamics and Control of Hybrid Active Orthoses (MIT-Pt/BSHHMS/0042/2008), BIOJOINTS - Development of advanced biological joint models for human locomotion biomechanics (PTDC/EMEPME/ 099764/2008), SFRH/BD/40164/2007, SFRH/BD/64477/200

    A Preliminary Investigation Comparing Craniofacial Metric Measurements and 3D Virtual Measurements

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    The development and advancement of new laser scanning techniques enables the capture of 3D imaging which can be quantitatively assessed for use on the human skull. I used a Polhemus Fast Scan Scorpion scanner to scan 8 skulls and evaluated the standard 24 metric measurements in Delta analysis software in comparison to standard metric measurements. The scanned measurements were then compared to the standard metric measurements using the same landmarks. Of the original 48 measurements, 33 (68.75%) fail to reject the null and 10 (20.83%) reject the null with the remaining 5 (10.41%) being unknown due to n=1 because of skull damage. The measurements that proved highly reliable were those associated with specific landmarks, and not those measurements that are based on landmarks and feel and considered arbitrary in this study. This study indicates that the use of the laser scanner can be a useful tool for rapid acquisition of skeletal and anatomical surfaces however, accurate location of landmarks and operator skill are of utmost importance in achieving accurate and reliable results

    Complexity Reduction in Image-Based Breast Cancer Care

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    The diversity of malignancies of the breast requires personalized diagnostic and therapeutic decision making in a complex situation. This thesis contributes in three clinical areas: (1) For clinical diagnostic image evaluation, computer-aided detection and diagnosis of mass and non-mass lesions in breast MRI is developed. 4D texture features characterize mass lesions. For non-mass lesions, a combined detection/characterisation method utilizes the bilateral symmetry of the breast s contrast agent uptake. (2) To improve clinical workflows, a breast MRI reading paradigm is proposed, exemplified by a breast MRI reading workstation prototype. Instead of mouse and keyboard, it is operated using multi-touch gestures. The concept is extended to mammography screening, introducing efficient navigation aids. (3) Contributions to finite element modeling of breast tissue deformations tackle two clinical problems: surgery planning and the prediction of the breast deformation in a MRI biopsy device

    Neural Radiance Fields: Past, Present, and Future

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    The various aspects like modeling and interpreting 3D environments and surroundings have enticed humans to progress their research in 3D Computer Vision, Computer Graphics, and Machine Learning. An attempt made by Mildenhall et al in their paper about NeRFs (Neural Radiance Fields) led to a boom in Computer Graphics, Robotics, Computer Vision, and the possible scope of High-Resolution Low Storage Augmented Reality and Virtual Reality-based 3D models have gained traction from res with more than 1000 preprints related to NeRFs published. This paper serves as a bridge for people starting to study these fields by building on the basics of Mathematics, Geometry, Computer Vision, and Computer Graphics to the difficulties encountered in Implicit Representations at the intersection of all these disciplines. This survey provides the history of rendering, Implicit Learning, and NeRFs, the progression of research on NeRFs, and the potential applications and implications of NeRFs in today's world. In doing so, this survey categorizes all the NeRF-related research in terms of the datasets used, objective functions, applications solved, and evaluation criteria for these applications.Comment: 413 pages, 9 figures, 277 citation

    Bio-Inspired Robotics

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    Modern robotic technologies have enabled robots to operate in a variety of unstructured and dynamically-changing environments, in addition to traditional structured environments. Robots have, thus, become an important element in our everyday lives. One key approach to develop such intelligent and autonomous robots is to draw inspiration from biological systems. Biological structure, mechanisms, and underlying principles have the potential to provide new ideas to support the improvement of conventional robotic designs and control. Such biological principles usually originate from animal or even plant models, for robots, which can sense, think, walk, swim, crawl, jump or even fly. Thus, it is believed that these bio-inspired methods are becoming increasingly important in the face of complex applications. Bio-inspired robotics is leading to the study of innovative structures and computing with sensory–motor coordination and learning to achieve intelligence, flexibility, stability, and adaptation for emergent robotic applications, such as manipulation, learning, and control. This Special Issue invites original papers of innovative ideas and concepts, new discoveries and improvements, and novel applications and business models relevant to the selected topics of ``Bio-Inspired Robotics''. Bio-Inspired Robotics is a broad topic and an ongoing expanding field. This Special Issue collates 30 papers that address some of the important challenges and opportunities in this broad and expanding field

    A Survey of Geometric Analysis in Cultural Heritage

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    We present a review of recent techniques for performing geometric analysis in cultural heritage (CH) applications. The survey is aimed at researchers in the areas of computer graphics, computer vision and CH computing, as well as to scholars and practitioners in the CH field. The problems considered include shape perception enhancement, restoration and preservation support, monitoring over time, object interpretation and collection analysis. All of these problems typically rely on an understanding of the structure of the shapes in question at both a local and global level. In this survey, we discuss the different problem forms and review the main solution methods, aided by classification criteria based on the geometric scale at which the analysis is performed and the cardinality of the relationships among object parts exploited during the analysis. We finalize the report by discussing open problems and future perspectives

    デジタルデザイン教育における中国の伝統的パターン要素の統合発展に関する研究

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    Cultural dissemination and artistic heritage represent a highly concentrated database of information in the past, which depends not only on the expansion of emerging digital media but also on the transformation of language and knowledge. Digital design with traditional patterns as elements is a continuous process from creative generation, material selection, and model establishment. The whole process is done based on the digital design course. The author conducts research from three aspects: theoretical knowledge, course operation exercises and after-school questionnaires, which is a process of integrating technology and art. The purpose of this course is not to discover new theories or new technologies, but to provide morphological possibilities for cultural symbols under existing digital technologies. The purpose is to try to construct new ideas and innovative digital technologies for traditional Chinese patterns, to find Possible paths for the inheritance of new traditional culture.北九州市立大
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