Scalable elastic systems architecture

Cloud computing has spurred the exploration and exploitation of elastic access to large scales of computing. To date the predominate building blocks by which elasticity has been exploited are applications and operating systems that are built around traditional computing infrastructure and programming models that are in-elastic or at best coarsely elastic. What would happen if application themselves could express and exploit elasticity in a fine grain fashion and this elasticity could be efficiently mapped to the scale and elasticity offered by modern cloud hardware systems? Would economic and market models that exploit elasticity pervade even the lowest levels? And would this enable greater efficiency both globally and individually? Would novel approaches to traditional problems such as quality of service arise? Would new applications be enabled both technically and economically? How to construct scalable and elastic software is an open challenge. Our work explores a systematic method for constructing and deploying such software. Building on several years of prior research, we will develop and evaluate a new cloud computing systems software architecture that addresses both scalability and elasticity. We explore a combination of a novel programming model and alternative operating systems structure. The goal of the architecture is to enable applications that inherently can scale up or down to react to changes in demand. We hypothesize that enabling such fine-grain elastic applications will open up new avenues for exploring both supply and demand elasticity across a broad range of research areas such as economic models, optimization, mechanism design, software engineering, networking and others.Department of Energy Office of Science (DE-SC0005365), National Science Foundation (1012798

Vector offset operators for deformable organic objects.

Many natural materials and most of living tissues exhibit complex deformable behaviours that may be characteriseda s organic. In computer animation, deformable organic material behaviour is needed for the development of characters and scenes based on living creatures and natural phenomena. This study addresses the problem of deformable organic material behaviour in computer animated objects. The focus of this study is concentrated on problems inherent in geometry based deformation techniques, such as non-intuitive interaction and difficulty in achieving realism. Further, the focus is concentrated on problems inherent in physically based deformation techniques, such as inefficiency and difficulty in enforcing spatial and temporal constraints. The main objective in this study is to find a general and efficient solution to interaction and animation of deformable 3D objects with natural organic material properties and constrainable behaviour. The solution must provide an interaction and animation framework suitable for the creation of animated deformable characters. An implementation of physical organic material properties such as plasticity, elasticity and iscoelasticity can provide the basis for an organic deformation model. An efficient approach to stress and strain control is introduced with a deformation tool named Vector Offset Operator. Stress / strain graphs control the elastoplastic behaviour of the model. Strain creep, stress relaxation and hysteresis graphs control the viscoelastic behaviour of the model. External forces may be applied using motion paths equipped with momentum / time graphs. Finally, spatial and temporal constraints are applied directly on vector operators. The suggested generic deformation tool introduces an intermediate layer between user interaction, deformation, elastoplastic and viscoelastic material behaviour and spatial and temporal constraints. This results in an efficient approach to deformation, frees object representation from deformation, facilitates the application of constraints and enables further development

Discrete Differential Geometry of Thin Materials for Computational Mechanics

Instead of applying numerical methods directly to governing equations, another approach to computation is to discretize the geometric structure specific to the problem first, and then compute with the discrete geometry. This structure-respecting discrete-differential-geometric (DDG) approach often leads to new algorithms that more accurately track the physically behavior of the system with less computational effort. Thin objects, such as pieces of cloth, paper, sheet metal, freeform masonry, and steel-glass structures are particularly rich in geometric structure and so are well-suited for DDG. I show how understanding the geometry of time integration and contact leads to new algorithms, with strong correctness guarantees, for simulating thin elastic objects in contact; how the performance of these algorithms can be dramatically improved without harming the geometric structure, and thus the guarantees, of the original formulation; how the geometry of static equilibrium can be used to efficiently solve design problems related to masonry or glass buildings; and how discrete developable surfaces can be used to model thin sheets undergoing isometric deformation