Sustaining Economic Exploitation of Complex Ecosystems in Computational Models of Coupled Human-Natural Networks

Understanding ecological complexity has stymied scientists for decades. Recent elucidation of the famously coined "devious strategies for stability in enduring natural systems" has opened up a new field of computational analyses of complex ecological networks where the nonlinear dynamics of many interacting species can be more realistically mod-eled and understood. Here, we describe the first extension of this field to include coupled human-natural systems. This extension elucidates new strategies for sustaining extraction of biomass (e.g., fish, forests, fiber) from ecosystems that account for ecological complexity and can pursue multiple goals such as maximizing economic profit, employment and carbon sequestration by ecosystems. Our more realistic modeling of ecosystems helps explain why simpler "maxi-mum sustainable yield" bioeconomic models underpinning much natural resource extraction policy leads to less profit, biomass, and biodiversity than predicted by those simple models. Current research directions of this integrated natu-ral and social science include applying artificial intelligence, cloud computing, and multiplayer online games

Interactive, internet delivery of visualization via structured prerendered multiresolution imagery.

We present a novel approach for latency-tolerant delivery of visualization and rendering results where client-side frame rate display performance is independent of source dataset size, image size, visualization technique or rendering complexity. Our approach delivers pre-rendered, multiresolution images to a remote user as they navigate through different viewpoints, visualization or rendering parameters. We employ demand-driven tiled, multiresolution image streaming and prefetching to efficiently utilize available bandwidth while providing the maximum resolution user can perceive from a given viewpoint. Since image data is the only input to our system, our approach is generally applicable to all visualization and graphics rendering applications capable of generating image files in an ordered fashion. In our implementation, a normal web server provides on-demand images to a remote custom client application, which uses client-pull to obtain and cache only those images required to fulfill the interaction needs. The main contributions of this work are: (1) an architecture for latency-tolerant, remote delivery of precomputed imagery suitable for use with any visualization or rendering application capable of producing images in an ordered fashion; (2) a performance study showing the impact of diverse network environments and different tunable system parameters on end-to-end system performance in terms of deliverable frames per second

Web-based Virtual Tour Using The Tour Into The Picture (TIP) Technique

Web-based Virtual Tour has become a desirable and demanded application, yet challenging due to the nature of web application’s running environment such as limited bandwidth and no guarantee of high computation power on the client side. Image-based rendering approach has attractive advantages over traditional 3D rendering approach in such Web Applications. Traditional approach, such as VRML, requires labor-intensive 3D modeling process, high bandwidth and computation power especially for photo-realistic virtual scenes. QuickTime VR and IPIX as examples of image-based approach, use panoramic photos and the virtual scenes that can be generated from photos directly skipping the modeling process. But, these image-based approaches may require special cameras or effort to take panoramic views and provide only one fixed-point look-around and zooming in-out rather than ‘walk around’, that is a very important feature to provide immersive experience to virtual tourists. The Web-based Virtual Tour using Tour into the Picture employs pseudo 3D geometry with image-based rendering approach to provide viewers with immersive experience of walking around the virtual space with several snap shots of conventional photos. 1

Image-Assisted Visualizations over Networks

The World Wide Web is incorporating recent advances in Internet technology and 3D graphics, promoting the spread of visualization over networks. To increase the efficiency of web-based 3D graphics systems including scientific visualizations, we present a method that utilizes previously rendered and transmitted images instead of transmitting 3D models to the client. Our Image-Based Rendering And Compression (IBRAC) method exploits spatial and temporal coherence between new and previously rendered synthetic images. Re-projecting color and visibility data accelerates the computation of new images while re-projecting the surface orientation eliminates inconsistencies in shading and lighting changes that plague other image-based rendering methods. We also present a new image data structure called an isomap, containing classification-interval data that enables a remote user to interactively classify volume data without loading the 3D dataset. Our approach produces rendering speed-ups of seven and more without visible degradation and compression ratios are a factor of two to ten times better than MPEG2 in our test cases. The approach is best suited for remote rendering applications where the client has limited rendering resources and network bandwidth, including wireless or palm computing applications. Keywords: Image-based rendering, compression, remote-rendering, web-based visualization, normal reprojection and isoma