WEB-IS (integrated system): an overall view

WEB-IS, Web-based Integrated System, allows remote, interactive visualization of large-scale 3-D data over the Internet, along with data analysis and data mining. In this paper, we discuss the overall structure of WEB-IS. Up until now we have developed three sub-modules geared towards geophysical problems. WEB-IS1 allows geoscientists to navigate through their 3-D geophysical data, such as seismic structures or numerical simulations, and interactively analyze the statistics or apply data-mining techniques, such as cluster analysis. WEB-IS2 lets a user control Amira (a powerful 3-D visualization package) remotely and analyze, render and view large datasets across the Internet. WEB-IS3 is an imaging service that enables the user to control the scale of features to view through interactive zooming. In the near future, we propose to integrate the three components together through a middleware framework called NaradaBrokering (iNtegrated Asynchronous Real-time Adaptive Distributed Architecture, a distributed messaging infrastructure that can be used to intelligently route data between the originators and registered consumers) without regard for time or location. As a result, WEB-IS will improve its scalability and acquire properties of fault-tolerance. WEB-IS uses a combination of Java, C++, and through the use of NaradaBrokering will seamlessly integrate the server-side processing and user interaction utilities on the client. The server takes care of the processor intensive tasks, such as visualization and data mining, and sends either the resulting bitmap image or statistical results to the middleware across the Internet for viewing. WEB-IS is an easy-to-use service, which will eventually help geoscientists collaborate from different sites in a natural manner. It will be very useful in the next 10 years because of the increasing number of space missions and geophysical campaigns.     

Remote data analysis,visualization and problem solving environment (PSE) based on wavelets in the geosciences

We discuss here the issues faced by earth scientists in analyzing and visualizing large datasets over a GRID-like setup from a client-server perspective. We approach this problem by using a remote, web-based visualization and data analysis framework, called WEB-IS, and by employing second-generation wavelets as a means for reducing the amount of data transferred and for extracting coherent features in complex geophysical flows and surface faulting patterns. As an example, we describe how onboard processors on satellites can function as a server for beaming down extracted information to the client computer on the ground, thus exemplifying WEB-IS as a viable middleware on a GRID network for geosciences.     

Dual aspects of mantle convection through time: Changes in global upper mantle temperature,Earth’s rotation,and global plate motion acceleration induced by mantle avalanches

We use modern and novel techniques to study the problems associated with detection and analysis of multitudinous seismic events, which form the background for isolated great earthquakes. This new approach involves multivariate analysis of low and large magnitude events recorded in space over a couple of centuries in time. We propose here the deployment of the clustering scheme both for extracting small local structures and large-scale trends in synthetic data obtained from four numerically simulated models with: uniform properties (U), a Parkfield-type asperity (A), fractal brittle properties (F), and multi-size-heterogeneity fault zone (M). The mutual nearest neighbor (mnn) clustering scheme allows for extraction of multi-resolutional seismic anomalies in both the spatio-temporal and multi-dimensional feature space. We demonstrate that the large earthquakes are correlated with a certain pathway of smaller events. Visualization of the anomalies by using a recently introduced visualization package Amira reveals clearly the spatio-temporal relationships between clusters of small, medium and large earthquakes, indicating significant stress relaxation across the entire fault region. We demonstrate that this mnn scheme can extract distinct clusters of the smallest events, which precede and follow a singularly large magnitude earthquake. These clusters form larger spatio-temporal structures comprising a series of large earthquakes. The link between the large and medium magnitude events is not so clearly understood. Short-ranged correlations are dominated by strong spatio-temporal anomalies, thus reflecting the global seismic properties of the entire fault zone.     

Visualization of multi-scale dynamics of hydrous cold plumes at subduction zones

Recent increases in the computational power of high-performance computing systems have led to a large gap between the high-resolution runs of numerical simulations—typically approaching 50–100 million tracers and 1–5 million grid points in two dimensions—and the modest resolution of 1–2 million pixels for conventional display devices. This technical problem is further compounded by the variety of fields produced by numerical simulations and the limited bandwidth available through the Internet in the course of collaborative ventures. We have developed a visualization system using the paradigm of web-based inquiry to address these mounting problems. We have employed, as a case study, a problem involving two-dimensional multi-scale dynamics of hydrous cold plumes at subduction zones. A Lagrangian marker method, in which the number of markers varies dynamically, is used to delineate the many different fields, such as temperature, viscosity, strain, and chemical composition. We found commercially available software to be insufficient for our visualization needs and so we were driven to develop a new set of tools tailored to high-resolution, multi-aspect, multi-scale simulations, and adaptable to many other applications in which large datasets involving tens of millions of tracers with many different fields are prevalent. In order to address this gap in visualization techniques, we have developed solutions for remote visualization and for local visualization. Our remote visualization solution is a web-based, zoomable image service (WEB-IS) that requires minimal bandwidth while allowing the user to explore our data through time, across many thermo–physical properties, and through different spatial scales. For local visualization, we found it optimal to use bandwidth-intensive, high-resolution display walls for performing parallel visualization in order to best comprehend the causal and temporal relationships between the multiple physical and chemical properties in a simulation.     

Web-based service of a visualization package “Amira” for the geosciences

Amira is a powerful three-dimensional visualization package that has been employed recently by the science and engineering communities to gain insight into their data. We discuss a new paradigm for the use of Amira in the Earth sciences that relies on the client-server paradigm. We have developed a module called WEB-IS2, which provides web-based access to Amira. This tool allows Earth scientists to manipulate Amira controls remotely and to analyze, render and view large datasets through the Internet without regard for time or location. This could have important ramifications for GRID computing.     

Current Trends and Demands in Visualization in the Geosciences

Geosciences, along with many other disciplines in science and engineering, faces an exponential increase in the amount of data generated from observation, experiment and large-scale, high-resolution 3-D numerical simulations. In this communication we describe the fundamentals of visualization necessary to meet these challenges. We present several alternative methodologies such as 2D/3D feature extraction, segmentation methods, and flow topology, to help better understand the physical structure of the data. We use AMIRA from TGS to demonstrate our concepts. Examples are drawn from fields in computational fluid dynamics, 3-D mantle convection and seismic tomography. Finally, we present our perspective on the future of visualization.     

gLucifer: next generation visualization framework for high-performance computational geodynamics

High-performance computing provides unprecedented capabilities to produce higher resolution 4-D models in a fraction of time. Thus, the need exists for a new generation of visualization systems able to maintain parity with the enormous volume of data generated. In attempting to write this much data to disk, each computational step introduces a significant performance bottleneck, yet most existing visualization software packages inherently rely on reading data in from a dump file. Available packages make this assumption of postprocessing at quite a fundamental level and are not very well suited for plotting very large numbers of specialized particles. This necessitates the creation of a new visualization system that meets the needs of large-scale geodynamic modeling. We have developed such a system, gLucifer, using a software framework approach that allows efficient reuse of our efforts in other areas of research. gLucifer is capable of producing movies of a 4-D data set “on the fly” (simultaneously with running the parallel scientific application) without creating a performance bottleneck. By eliminating most of the human efforts involved in visualizing results through postprocessing, gLucifer reconnects the scientist to the numerical experiment as it unfolds. Data sets that were previously very difficult to even manage may be efficiently explored and interrogated without writing to disk, and because this approach is based entirely on memory distributed across as many processors as are being utilized by the scientific application, the visualization solution is scalable into terabytes of data being rendered in real time.     

The Costs of Financial Crises: Resource Misallocation,Productivity, and Welfare in the 2001 Argentine Crisis

Financial crises in emerging market countries appear to be very costly: both output and a host of partial welfare indicators decline dramatically. The magnitude of these costs is puzzling both from an accounting perspective – factor usage does not decline as much as output, resulting in large falls in measured productivity – and from a theoretical perspective. With the aim of resolving this puzzle, we present a framework that allows us to do the following. First, we account for changes in a country's measured productivity during a financial crisis as the result of changes in the underlying technology of the economy, the efficiency with which resources are allocated across sectors, and the efficiency of the resource allocation within sectors, driven both by reallocation amongst existing plants and by entry and exit. Second, we measure the change in the country's welfare resulting from changes in productivity, government spending, the terms of trade, and a country's international investment position. We apply this framework to the Argentine crisis of 2001 using a unique establishment level dataset and we find that more than half of the, roughly, 10 percent decline in measured total factor productivity can be accounted for by deteriorations in the allocation of resources both across and within sectors. We measure the decline in welfare to be of the order of one‐quarter of one year's gross domestic product.     

Interactive 3-D computation of fault surfaces using level sets

Deformable implicit surfaces, implemented with level set methods, have demonstrated a great potential in the computational sciences for applications such as modeling, simulation, and segmentation. They allow implicit handling of complex topologies deformed by operations where large changes can occur without destroying the level set representation. The use of level set techniques for the computation and segmentation of plane-like and high positive curvature features is nontrivial. We present a technique for representing and extracting fault surfaces from 3-D seismic attribute data such that 2-manifolds can be interactively computed and segmented. We present our approach as an interactive workflow that generates highly accurate fault surfaces.     

Visualization of time-dependent dynamics of postglacial rebound

Postglacial rebound is a major geological process which plays an important role in many areas in the earth sciences. Up to now, most of the images derived from studies of the glacial isostatic adjustment phenomenon have been concerned with surface signatures, such as the uplift and gravity anomalies and not much attention has been paid on the dynamical responses in the mantle. We will make use of the 3D visualization package Amira to depict both the external and internal deformation histories of the transient viscoelastic flow inside the mantle induced by postglacial uplift. Of particularly great interest are the transient displacement fields and shear heating inside the mantle. This same visualization technology can be brought to bear in the future for visualizing tsunami waves in ocean basins excited by earthquakes, volcanic eruptions and InSAR images. We have also integrated the visualization results into the Google Earth virtual globe by combining this scheme with the Amira package to provide a better geographical and dynamical context.     

Heterogeneous technology and panel data: The case of the agricultural production function

Economic growth involves reallocating resources from traditional to new techniques of production, creating new relationships between particular resources and productivity. The paper analyzes the implications of this process on the estimation of agricultural production functions using a panel of countries. The data includes a measure of capital in agriculture absent from most studies. We employ a heterogeneous technology framework where implemented technology is chosen jointly with inputs to interpret information obtained in the empirical analysis of panel data. In this framework, estimates depend upon the economic environment, which is represented by state variables. It turns out that the old problem of identifying the production function cannot be resolved through the use of instrumental variables, but can be resolved using the allocation error. The paper discusses the scope for replacing country and time effects by observed state variables. The empirical results differ from those reported in the literature for cross-country studies, largely in augmenting the elasticities of capital and land and reducing those of fertilizer and labor. The evaluation of the marginal value productivity accounts for the flow of capital and fertilizer to agriculture and the flow of labor to other sectors, thereby contributing to overall economic growth.     

Ubiquitous interactive visualization of 3D mantle convection using a web-portal with Java and Ajax framework

We have developed a new strategy and espouse a novel paradigm for large-scale computing and real-time interactive visualization. This philosophy calls for intense interactive sessions for a couple of hours at a time at the expense of storing data on many disk drives during regular or heroic runs on massively parallel systems. We have already carried out successfully real-time volume-rendering visualization by employing hundreds of processors for a grid with over 25 million unknowns. Both Cartesian and spherical 3D mantle convection are visualized. The volume-rendered images are viewed on a large display device, with many panels holding around 13 million pixels. We will employ a software strategy involving an hierarchical rendering service, which will have as software an Ajax interface for interactive visualization of large data sets on many different platforms from desktop PC’s to hand-held devices, such as the OQO and the Nokia N-800. An option for stereo viewing is also implemented. We have installed a user interface as web application, using Java and Ajax framework in order to achieve over the Internet reasonable accessibility to our ongoing runs. Our goal is to expand the array of interactive devices, which will make it feasible to carry out ubiquitous visualization and monitoring of large-scale simulations or onsite events and to allow for collaborations across oceans.     

The ‘curse of dimensionality’ resolved: The effects of climate change and trade barriers in large dimensional modelling

Solving large scale optimisation problems over space and time quickly generates a computational impasse, termed the ‘curse of dimensionality’. This severely limits the practical use of economic models, especially for determining the effects of climate change and protectionist trade policies. In this paper, we employ an innovative approach to solving (otherwise unsolvable) large scale systems through the use of parallel processing methods and a proper ordering of variables and equations in a ‘Nested Doubly Bordered Block Diagonal’ form. We illustrate how the approach can be used to solve an intertemporal CGE model with more than 500 million equations. Using existing damage functions, the framework allows us to determine the impact of climate change on long-run economic growth for 112 countries as a result of the effect of sea-level rise on land endowments, variation in crop yields and productivity and shifts in the demand for energy and transportation. We also compare our solution to more common (and smaller dimensional) recursive methods, in terms of both the economic effects of climate change and potential increases in trade barriers, showing the power and efficiency of our computational approach and parallel processing routine.     

Human-induced earthquakes,risk salience,and housing values

Oklahoma’s households have recently faced several thousand higher-probability but low-impact earthquakes induced by nearby shale gas development. This type of seismic activity is different from natural-occurring earthquakes, which are generally constituted by one, high-loss event. We investigate the mechanisms through which earthquakes may influence household perceptions of risk by modeling changes to property values in and out of seismically-active zones. We estimate that the induced earthquakes are spatially concentrated, which is partially influenced by governmental limits placed on natural gas production and wastewater injections. Additionally, we explore the underlying measure of earthquake intensity and identify its importance in modeling seismic impacts. Controlling for the stock-flow dynamics of seismicity through time, we estimate that Oklahoma County’s cumulative experience of earthquakes led to a diminution of property values. The impacts are further exacerbated by risk-saliency effects, as reflected in declining values associated with nearby wastewater injections and natural gas production.     

An assessment of environmental sustainability in Northern Australia using the ecological footprint and with reference to Indigenous populations and remoteness

Nearly a third of the population of the Northern Territory of Australia is Indigenous and the Northern Territory environment has sustained Indigenous cultures for millennia. Under traditional management the land area used per person was relatively large but few resources were imported. Although the reliance on local resources has declined through interactions with Western society, at least some exploitation of the natural environment remains. This means that higher-density urban populations, which are largely non-Indigenous, have larger footprints than rural and remote populations, which are largely Indigenous. Thus Northern Territory urban populations are not necessarily requiring less land, but are just offsetting their land impacts to other regions. Finally, Indigenous ecological footprints are found to be heavily influenced by the provision of government services.     

Visualization of tsunami waves with Amira package

In recent years numerical investigations of tsunami wave propagation have been spurred by the magnitude 9.3 earthquake along the Andaman–Sumatra fault in December, 2004. Visualization of tsunami waves being modeled can yield a much better physical understanding about the manner of wave propagation over realistic seafloor bathymetries. In this paper we will review the basic physics of tsunami wave propagation and illustrate how these waves can be visualized with the Amira visualization package. We have employed both the linear and nonlinear versions of the shallow-water wave equation. We will give various examples illustrating how the files can be loaded by Amira, how the wave-heights of the tsunami waves can be portrayed and viewed with illumination from light sources and how movies can be used to facilitate physical understanding and give important information in the initial stages of wave generation from interaction with the ambient geological surroundings. We will show examples of tsunami waves being modeled in the South China Sea, Yellow Sea and southwest Pacific Ocean near the Solomon Islands. Visualization should be a part of any training program for teaching the public about the potential danger arising from tsunami waves. We propose that interactive visualization with a web-portal would be useful for understanding more complex tsunami wave behavior from solving the 3-D Navier–Stokes equation in the near field.     

The Impact of the 9/11 Events on the American and French Stock Markets

Markets reacted strongly to the World Trade Center attacks both in Europe and in the United States. The extent of this crisis was difficult to assess at the time, underlining the need for a specific tool to measure the magnitude of financial crises. A first measure was recently proposed and applied to the foreign exchange market by Zumbach et al. (2000a,b ). Their measure relies on an analogy with geophysics; the related index of market shocks (IMS) that we propose here is also the counterpart of the Richter scale used for earthquakes. We apply this measure on the French and the American stock markets to put large market events into perspective. The crisis triggered by the September attacks was actually the worst since 1987, and the ninth worst when compared to major historical ones.     

Parallel visualization of seismic wave propagation

Today parallel visualization of massive datasets from observation and numerical simulation of seismic waves is one of the major goals of geoscience community. A majority of these datasets are time-varying volume data (TVVD), also known as 4D field data. The difficulty of visualizing them on distributed parallel system mainly lies in the algorithm designing for distributed preprocessing of raw datasets, hierarchical point-to-point or collective communication implementation based on distributed data allocation, synchronous volume rendering techniques. In this work we present viable solutions for preprocessing of raw data sets, novel algorithms of parallel rendering and display matrix. Our main objective is focused on the parallel visualization of results coming from full 4D seismic wave propagation simulations.     

On the relationship between population change and sustainable development

This paper investigates the relationship between population growth and economic growth, through the study of fertility choices and their effects on natural resources. It aims at analyzing the interactions between endogenous fertility choices and the environment and their link to the sustainable matter. We analyze a growth model driven by natural resources and without production, where agents have jointly to determine consumption and fertility, taking into account the effects of their decisions on the dynamics of natural resources. We adopt the most optimistic view on natural capital (it generates endogenous growth) and the weakest notion of sustainable paths (all variables are positive): in such a framework we expect that sustainable paths exist. We instead show that this is not always true. In fact, even if renewal capacity of natural resources is unbounded, not always can a sustainable path be found: this depends on the difference between the stationary fertility rate and the mortality rate. If the stationary fertility is lower than the mortality rate, a sustainable path will not be found, and in such a case public intervention is necessary in order to address the economy along a sustainable path. This can simply be done through policies affecting public attention to environmental protection or the intensity of the dilution effect.     

Regulation, market structure and service trade liberalization

In this paper, we develop a theoretical method to quantify the importance of regulation and market structure on the success of service trade liberalization. For this purpose, we incorporate a single imperfectly competitive service sector that can take on various market structures into a standard computational general equilibrium model. We apply our framework to analyze the impact of partial telecom liberalization in Tunisia. We show that if the regulatory environment guarantees competition, Tunisia's welfare can improve up to 0.65%. If a cartel is formed between the domestic incumbent and foreign entrant, however, Tunisia's welfare can drop up to 0.25%. Our results thus call for Tunisia among other developing countries to step up its pro-competitive regulatory reforms while liberalizing its telecom sector.