5,451 research outputs found
Distributed STOVL Operations and Air-Mobility Support: Addressing the Mismatch between Requirements and Capabilities
A joint logistics approach based on U.S. Air Force air-mobility assets, especially if enhanced by a medium-sized tanker/transport aircraft, can offer significant advantages in the flexibility, sustainability, and safety of Marine distributed short-takeoff–vertical-landing operations, particularly in the face of sophisticated antiaccess/area-denial capabilities
Periodic standing-wave approximation: nonlinear scalar fields, adapted corrdinates, and the eigenspectral method
Journal ArticleThe periodic standing wave (PSW) method for the binary inspiral of black holes and neutron stars computes exact numerical solutions for periodic standing-wave spacetimes and then extracts approximate solutions of the physical problem, with outgoing waves. The method requires solution of a boundary-value problem with a mixed (hyperbolic and elliptic) character. We present here a new numerical method for such problems, based on three innovations: (i) a coordinate system adapted to the geometry of the problem, (ii) an expansion in multipole moments of these coordinates and a filtering out of higher moments, and (iii) the replacement of the continuum multipole moments with their analogs for a discrete grid. We illustrate the efficiency and accuracy of this method with nonlinear scalar model problems. Finally, we take advantage of the ability of this method to handle highly nonlinear models to demonstrate that the outgoing approximations extracted from the standing-wave solutions are highly accurate even in the presence of strong nonlinearities
Thawing out the Cold Record: Some Thoughts on How Videotaped Records May Affect Traditional Standards of Deference on Direct and Collateral Review
Appellate courts are unable to “smell the smoke of battle” from a trial. For this reason, a trial court’s decision is owed deference when examining an appeal. Video technology makes this reason for deference less relevant
Thawing out the Cold Record: Some Thoughts on How Videotaped Records May Affect Traditional Standards of Deference on Direct and Collateral Review
Appellate courts are unable to “smell the smoke of battle” from a trial. For this reason, a trial court’s decision is owed deference when examining an appeal. Video technology makes this reason for deference less relevant
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VigNet: Grounding Language in Graphics using Frame Semantics
This paper introduces Vignette Semantics, a lexical semantic theory based on Frame Semantics that represents conceptual and graphical relations. We also describe a lexical resource that implements this theory, VigNet, and its application in text-to-scene generation
Determining the Kappa Distributions of Space Plasmas from Observations in a Limited Energy Range
Spacecraft observations allow us to reconstruct the velocity distributions of space plasmas, which fully describe the kinetic state of the plasma. Space plasmas often exist in stationary states out of equilibrium, which are typically described by kappa distributions. Thus, the kappa index and temperature that govern these distributions are parameters that need to be determined for a full and accurate description of these plasmas. In this study, we demonstrate a novel and reliable way to determine the kappa index and temperature of plasma distribution functions constructed from counts observed in a narrow energy range by typical electrostatic sensors. Our method applies to cases in which the high-energy tail of the plasma is observed with significant uncertainty, or not observed at all. For the validation of our method, we produce pseudo-observations for typical input plasma parameters, specifically considering the design of the ion plasma instrument SWA-PAS on board the Solar Orbiter mission. Our method reliably estimates the relevant plasma parameters by fitting the angular spread of the distribution in a narrow energy range around the core bulk energy. We compare the output of our technique with the input parameters used to generate artificial data for a selected range of the kappa index and the temperature, and for a bulk energy typical for the solar wind. In addition, we study the effects of Poisson errors on the instrument's counting statistics, test our method against Helios 2 measurements, and discuss its potential applications and limitations
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Frame Semantics in Text-to-Scene Generation
3D graphics scenes are difficult to create, requiring users to learn and utilize a series of complex menus, dialog boxes, and often tedious direct manipulation techniques. By giving up some amount of control afforded by such interfaces we have found that users can use natural language to quickly and easily create a wide variety of 3D scenes. Natural language offers an interface that is intuitive and immediately accessible by anyone, without requiring any special skill or training. The WordsEye system (http://www.wordseye.com) has been used by several thousand users on the web to create over 10,000 scenes. The system relies on a large database of 3D models and poses to depict entities and actions. We describe how the current version of the system incorporates the type of lexical and real-world knowledge needed to depict scenes from language
Bacteria Source Tracking to Support Watershed Planning, Little Sac River, Southwest Missouri
The Little Sac Watershed in Greene and Polk Counties of southwest Missouri was placed on the 303d list for bacteria impairment in 1998 (WCO 2016). In 2006, a Total Maximum Daily Load (TMDL) was developed for the watershed to address bacteria impairments within the Little Sac River and an initial watershed management plan was finalized in 2010 (Baffaut 2006, WCO 2009). The Watershed Committee of the Ozarks (WCO) is presently updating that plan with the most recent information on bacteria within the watershed. As part of that process, the WCO has contracted the Ozarks Environmental and Water Resources Institute (OEWRI) at Missouri State University (MSU) to complete a bacteria source tracking study within the watershed to identify potential bacteria pollution sources. The purpose of this study is to collect water samples throughout the watershed and evaluate bacteria DNA using real-time PCR for specific marker genes that can help identify specific bacteria sources from different locations in the Little Sac River watershed
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