6,441 research outputs found
The use of computational fluid dynamics to assess the hull resistance of concept autonomous underwater vehicles
No full textAutonomous Underwater Vehicles (AUV’s) provide an important tool for collecting detailed scientific information from the oceans depths. The hull resistance of an AUV is an important factor in determining the powering requirements and range of the vehicle. This paper discusses the use of Computational Fluid Dynamics (CFD) to determine the hull resistance of three existing AUV’s, of differing shape and size. The predictions are compared with available experimental data and good agreement found. This work has demonstrated that with use of suitable shape parameterisation it is possible to carry out concept design evaluation using a RANS flow solver
Letter from J. R. Eakin to Stephen Mather
No full textLetter from J. R. Eakin to Stephen T. Mather about expenses and reconstruction of the Kaibab Trail
Grid-based GA path planning with improved cost function for an over-actuated hover-capable AUV
No full textFor an AUV to perform a long-range mission with its maximum endurance, its energy consumption during transit must be kept to a minimum. This paper presents an improved cost function for a grid-based genetic algorithm (GA) path planning in 2D static environments. The proposed function consists of energy consumption terms that are estimated according to dynamics of a hover-capable AUV - notably Delphin2 AUV. It seeks for a path that requires least effort for the vehicle to move along. A simulation was written in Matlab and the outcomes of the GA with the improved cost function are compared with the ones of a GA with an optimal distance approach as well as an A* approach. It is found that outcomes of an improved cost function require less energy compared with the other technique
The Vindication of the World Essays Engaging with Stephen Phillips
No full textStephen Phillips has devoted his career to excavating some of the most valuable gems of Indian philosophy and bringing them into conversation with contemporary thought. This volume honors him and follows his lead by continuing his lifelong project: faithfully interpreting Sanskrit texts to think along with their authors about ideas that still perplex us today.
It features ten new essays focusing on epistemology, logic, and metaphysics from outstanding philosophers and scholars of Sanskrit philosophy, with contributions varying in methodology: both historical and cross-cultural. Further, in addition to essays on Nyāya and Advaita Vedānta, it engages with Navya-Nyāya (“new Nyāya”), an important but understudied part of Indian philosophy. Through these investigations, in conversation with Phillips\u27s groundbreaking work, the contributors show the value of cross-cultural engagement for philosophical progress.
The Vindication of the World will be of interest to scholars and advanced students working in Indian philosophy, comparative philosophy, and, more generally, epistemology, logic, and metaphysics.https://scholarworks.smith.edu/phi_books/1008/thumbnail.jp
cohort study
No full textAbstract not available.Nitaa Eapen, Amit Kochar, Mark D Lyttle, Natalie Phillips, John A Cheek, Jeremy Furyk, Jocelyn Neutze, Silvia Bressan, Amanda Williams, Stephen Hearps, Ed Oakley, Stuart R Dalziel, Meredith L Borlan
The New Keynesian Phillips Curve and Lagged Inflation: A Case of Spurious Correlation?
No full textThe New Keynesian Phillips Curve (NKPC) specifies a relationship between inflation and a forcing variable and the current period’s expectation of future inflation. Most empirical estimates of the NKPC, typically based on Generalized Method of Moments (GMM) estimation, have found a significant role for lagged inflation, producing a “hybrid” NKPC. Using U.S. quarterly data, this paper examines whether the role of lagged inflation in the NKPC might be due to the spurious outcome of specification biases. Like previous investigators, we employ GMM estimation and, like those investigators, we find a significant effect for lagged inflation. We also use time varying-coefficient (TVC) estimation, a procedure that allows us to directly confront specification biases and spurious relationships. Using three separate measures of expected inflation, we find strong support for the view that, under TVC estimation, the coefficient on expected inflation is near unity and that the role of lagged inflation in the NKPC is spurious.New Keynesian Phillips Curve; time-varying coefficients; spurious relationships
Letter from J. R. Eakin to Stephen Mather
No full textLetter from J. R. Eaking to the National Park Service director about changes to the Grand Canyon National Park boundaries, and access to water near the Buggeln property on Desert View road
What do New-Keynesian Phillips Curves imply for price-level targeting?
No full textThis paper extends the analysis of price-level targeting to a model including the New-Keynesian Phillips Curve. We examine the inflation-output variability tradeoffs implied by optimal inflation and price-level rules. In previous work with the Neoclassical Phillips Curve, we found that the choice between inflation targeting and price-level targeting depended on the amount of persistence in the output gap. That is, if the output gap was not too persistent, or if lagged output did not enter the aggregate supply function, then inflation targets were preferred to price-level targets. When we start with a New-Keynesian Phillips Curve, the amount of persistence in the output gap still affects the relative placement of the inflation-output variability tradeoff. But, contrary to the Neoclassical case, even where the persistence of the output gap in the aggregate supply function is small or nonexistent, the price-level- targeting regime still results in a more favorable tradeoff between output and inflation variability than does an inflation-targeting regime.Phillips curve ; Monetary policy ; Inflation (Finance)
Tools for quantitative comparison of preservation strategies
No full textThis report describes the tools developed by IT Innovation for quantitative comparison of preservation strategies. The tools have been open sourced and are publicly available on a website which includes documentation and features for bug reporting and new functionality requests
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