The 1990 progress report and future plans

This document describes the progress and plans of the Artificial Intelligence Research Branch (RIA) at ARC in 1990. Activities span a range from basic scientific research to engineering development and to fielded NASA applications, particularly those applications that are enabled by basic research carried out at RIA. Work is conducted in-house and through collaborative partners in academia and industry. Our major focus is on a limited number of research themes with a dual commitment to technical excellence and proven applicability to NASA short, medium, and long-term problems. RIA acts as the Agency's lead organization for research aspects of artificial intelligence, working closely with a second research laboratory at JPL and AI applications groups at all NASA centers

Methodological Investigations in Agent-Based Modelling: With Applications for the Social Sciences

This open access book examines the methodological complications of using complexity science concepts within the social science domain. The opening chapters take the reader on a tour through the development of simulation methodologies in the fields of artificial life and population biology, then demonstrates the growing popularity and relevance of these methods in the social sciences. Following an in-depth analysis of the potential impact of these methods on social science and social theory, the text provides substantive examples of the application of agent-based models in the field of demography. This work offers a unique combination of applied simulation work and substantive, in-depth philosophical analysis, and as such has potential appeal for specialist social scientists, complex systems scientists, and philosophers of science interested in the methodology of simulation and the practice of interdisciplinary computing research.

Evaluation of Gas-Assisted Gravity Drainage EOR Process Applicability in a Louisiana Oil Field through Experiments and Reservoir Simulation

The Gas-Assisted Gravity Drainage (GAGD) process was developed as an alternative to conventional gas injection enhanced oil recovery (EOR) processes, which suffer from their inherent weakness of combating gravity segregation. The GAGD process, however, is aimed at taking advantage of this phenomenon and consists of using horizontal producers near the bottom of the payzone while injecting gas using vertical injection wells. It is hypothesized that the injected gas will rise to the top, thereby forming a gas cap while displacing reservoir brine/oil downward towards the producers. In this study, a single-well alternative to the multi-well GAGD process was investigated to determine the operating constraints that would result in maximum oil recovery, and the main areas of improvement/adaptation for implementation in the Buckhorn Field, an onshore Louisiana reservoir. In the newly proposed process, the gas injection and fluid production occur along the same wellbore; however, they would be located in different sections with the production completions in either a horizontal section of the well or in a lower-lying section of a vertical well. The study was comprised of reservoir condition coreflooding experiments to elucidate the pertinent data to the field application of this single-well GAGD process. This data was then used in field-scale numerical simulations to optimize the proposed process with regards to maximum oil recovery by investigating various well locations/configurations, and production strategies. In order to frame the proposed processes’ technical feasibility they were compared to other commonly implemented EOR processes, such as Continuous Gas Injection and Water-Alternating-Gas. Finally, an economic assessment of all of the investigated gas EOR processes was carried out to quantify the risk associated with their application. For this purpose, a cashflow analysis was conducted using Excel after which Crystal Ball was utilized to generate the confidence intervals for selected economic performance indicators. The numerical simulation study revealed that the multi-well GAGD process resulted in the highest oil recovery (50–58 %ROIP or 2.0–2.6 million STBO) while the economic study showed that all GAGD process variations would be profitable. However, the vertical single-well GAGD process ranked the highest based on the Internal Rate of Return and the Profitability Index

ME-EM 2009 Annual Report

Table of Contents Energy Systems Health Systems Faculty & Staff Students Alumni Resources Graduates Publications ME-EM Communityhttps://digitalcommons.mtu.edu/mechanical-annualreports/1009/thumbnail.jp

A lightweight distributed super peer election algorithm for unstructured dynamic P2P systems

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Engenharia Electrotécnica e de ComputadoresNowadays with the current growth of information exchange, and the increasing mobility of devices, it becomes essential to use technology to monitor this development. For that P2P networks are used, the exchange of information between agencies is facilitated, these now being applied in mobile networks, including MANETs, where they have special features such as the fact that they are semi-centralized, where it takes peers more ability to make a greater role in the network. But those peer with more capacity, which are used in the optimization of various parameters of these systems, such as optimization\to research, are difficult to identify due to the fact that the network does not have a fixed topology, be constantly changing, (we like to go online and offline, to change position, etc.) and not to allow the exchange of large messages. To this end, this thesis proposes a distributed election algorithm of us greater capacity among several possible goals, enhance research in the network. This includes distinguishing characteristics, such as election without global knowledge network, minimal exchange of messages, distributed decision made without dependence on us and the possibility of influencing the election outcome as the special needs of the network

A complex systems approach to constructing better models for managing financial markets and the economy

We outline a vision for an ambitious program to understand the economy and financial markets as a complex evolving system of coupled networks of interacting agents. This is a completely different vision from that currently used in most economic models. This view implies new challenges and opportunities for policy and managing economic crises. The dynamics of such models inherently involve sudden and sometimes dramatic changes of state. Further, the tools and approaches we use emphasize the analysis of crises rather than of calm periods. In this they respond directly to the calls of Governors Bernanke and Trichet for new approaches to macroeconomic modelling. Graphical abstrac

A complex systems approach to constructing better models for managing financial markets and the economy

We outline a vision for an ambitious program to understand the economy and financial markets as a complex evolving system of coupled networks of interacting agents. This is a completely different vision from that currently used in most economic models. This view implies new challenges and opportunities for policy and managing economic crises. The dynamics of such models inherently involve sudden and sometimes dramatic changes of state. Further, the tools and approaches we use emphasize the analysis of crises rather than of calm periods. In this they respond directly to the calls of Governors Bernanke and Trichet for new approaches to macroeconomic modelling.The publication of this work was partially supported by the European Union’s Seventh Framework Programme (FP7/2007-2013) under grant agreement No. 284709, a Coordination and Support Action in the Information and Communication Technologies activity area (‘FuturICT’ FET Flagship Pilot Project). Doyne Farmer, Mauro Gallegati and Cars Hommes also acknowledge financial support from the EU-7th framework collaborative project “Complexity Research Initiative for Systemic InstabilitieS (CRISIS)”, grant No. 288501. Cars Hommes acknowledges financial support from the Netherlands Organization for Scientific Research (NWO), project “Understanding Financial Instability through Complex Systems”. None of the above are responsible for errors in this paper.Publicad

TRIBOLOGICAL SYSTEMS FOR THE EVALUATION OF SUPERCRITICAL CARBON DIOXIDE STERILIZED ULTRA-HIGH MOLECULAR WEIGHT POLYETHYLENE

Polymeric biomaterials are especially susceptible to changes in mechanical and surface material properties as a result of sterilization processes that involve heat, moisture and/or irradiation. This is problematic for polymeric materials used in total joint replacement bearings, as these constructs must retain their superior mechanical and tribological properties over their expected 10-20 years of implantation. A younger more active patient population has now exacerbated this longevity issue with service lifetimes of 20+ years now being expected. Supercritical phase carbon dioxide (SC-CO2) is an industrial solvent that has shown great promise as a sterilizing agent in the food industry. Recently, SC-CO2 has adapted for the sterilization of medical grade total joint replacement ultra-high molecular weight polyethylene (UHMWPE), reducing the exposure of the polymer to the detrimental effects of heat, moisture and/or radiation. Further research is needed however to evaluate the effect of SC-CO2 sterilization on the mechanical, surface and tribological properties of UHMWPE over time. This dissertation explores the use of SC- CO2 sterilization for UHMWPE for total joint applications from a tribological perspective. It seeks to investigate and quantify fundamental tribological measures that occur at the bearing contact of total joint replacements, and it formulates and develops new experimental techniques and testing systems to investigate these tribological phenomena. This dissertation explores the hypothesis that SC-CO2 sterilization does not significantly affect the mechanical and/or tribological properties of UHMWPE, making it a \u27material safe\u27 sterilization treatment for this sensitive polymer. To answer this hypothesis, this dissertation develops and employs a series of clinically relevant wear testing methodologies in conjunction with industry standard material and surface characterization techniques to evaluate the efficacy of SC-CO2 for UHMWPE sterilization