1,443 research outputs found
Recommended from our members
Cryogenic Stress-Driven Grain Growth Observed via Microcompression with in situ Electron Backscatter Diffraction
The deformation of materials at cryogenic temperature is of interest for space, arctic, and fundamental science applications. In this work, a custom-built cooling system attached to a commercial picoindenter was used for in situ cryogenic microcompression testing of equal-channel angular-pressed copper with real-time electron backscatter diffraction. Stress-driven grain growth at cryogenic temperatures was observed during a series of elastic and plastic deformations. These results provide direct evidence for the previously predicted phenomenon, whereas previous ex situ examinations demonstrated coarsening after cryogenic loading when samples were not maintained at cryogenic temperatures between deformation and characterization
On the Optimization of Visualizations of Complex Phenomena
The problem of perceptually optimizing complex visualizations is a difficult one, involving perceptual as well as aesthetic issues. In our experience, controlled experiments are quite limited in their ability to uncover interrelationships among visualization parameters, and thus may not be the most useful way to develop rules-of-thumb or theory to guide the production of high-quality visualizations. In this paper, we propose a new experimental approach to optimizing visualization quality that integrates some of the strong points of controlled experiments with methods more suited to investigating complex highly-coupled phenomena. We use human-in-the-loop experiments to search through visualization parameter space, generating large databases of rated visualization solutions. This is followed by data mining to extract results such as exemplar visualizations, guidelines for producing visualizations, and hypotheses about strategies leading to strong visualizations. The approach can easily address both perceptual and aesthetic concerns, and can handle complex parameter interactions. We suggest a genetic algorithm as a valuable way of guiding the human-in-the-loop search through visualization parameter space. We describe our methods for using clustering, histogramming, principal component analysis, and neural networks for data mining. The experimental approach is illustrated with a study of the problem of optimal texturing for viewing layered surfaces so that both surfaces are maximally observable
DIAL with heterodyne detection including speckle noise: Aircraft/shuttle measurements of O3, H2O, and NH3 with pulsed tunable CO2lasers
A parametric analysis of DIAL sensitivity with heterodyne detection is presented and comparisons with direct detection are discussed. Examples are given for monitoring vertical distributions of O3, H2O, and NH3 using a ground-, aircraft-, or shuttle-based pulsed tunable CO2 laser DIAL system. Results indicate that maximum sensitivity at minimum laser energy per measurement requires multiple pulse operation with the energy per pulse selected so that the measured photon rate is approximately equal to the detector IF bandwidth. Measurement sensitivities can be maximized and interference effects minimized by fine adjustment of measurement frequencies using the tunability of high pressure lasers. The use of rare isotope lasers minimizes loss due to CO2 atmospheric absorption
DIAL with heterodyne detection including speckle noise: Aircraft/shuttle measurements of O3, H2O, and NH3 with pulsed tunable CO2 lasers
Atmospheric trace constituent measurements with higher vertical resolution than attainable with passive radiometers are discussed. Infrared differential absorption lidar (DIAL), which depends on Mie scattering from aerosols, has special advantages for tropospheric and lower stratospheric applications and has great potential importance for measurements from shuttle and aircraft. Differential absorption lidar data reduction involves comparing large amplitude signals which have small differences. The accuracy of the trace constituent concentration inferred from DIAL measurements depends strongly on the errors in determining the amplitude of the signals. Thus, the commonly used SNR expression (signal divided by noise in the absence of signal) is not adequate to describe DIAL measurement accuracy and must be replaced by an expression which includes the random coherent (speckle) noise within the signal. A comprehensive DIAL computer algorithm is modified to include heterodyne detection and speckle noise. Examples for monitoring vertical distributions of O3, H2O, and NH3 using a ground-, aircraft-, or shuttle-based pulsed tunable CO2 laser DIAL system are given
Small Satellite Regulation in 2021
Small satellite innovation has advanced rapidly over the past decade, and regulators are working hard to keep up. In August 2020, a new streamlined licensing process became available at the Federal Communications Commission (FCC) for certain small satellite missions to bring satellite licensing procedures up to date with technological innovation. This new optional licensing process applies to small satellites meeting certain criteria, such as a constellation of ten or fewer satellites, a wet mass of 180 kg or less, a shorter in-orbit lifetime, and a low orbital debris risk. The streamlined licensing process provides for reduced fees and decreased regulatory barriers for qualifying satellite operators, enabling the deployment of low-cost commercial satellite systems that were previously untenable under the FCC’s rules. This new process provides operators with an intermediate licensing option in addition to the FCC’s existing processes for satellite authorization, including its experimental, amateur, and standard Part 25 commercial satellite licensing procedures, giving small satellite operators flexibility to choose the licensing procedure that best matches their operational and spectrum needs. Operators with satellite systems meeting the criteria for streamlined licensing have already started to apply for FCC authorizations, and there are lessons to be learned from FCC review and grant of these early applications.
The rules governing orbital debris mitigation, space situational awareness and space traffic management have also evolved. In addition to the FCC, satellite licensing involves a variety of other federal agencies. As part of the FCC authorization process, the FCC will coordinate spectrum use with the National Telecommunications and Information Administration (NTIA) if federal systems operate in the same spectrum. The Federal Aviation Administration (FAA) licenses commercial launch and reentry vehicles well as commercial spaceports. Commercial remote sensing satellites require a license from the National Oceanic and Atmospheric Administration (NOAA). The Departments of Commerce and State license exports of space technology
Innovation in Adversity
Adverse experiences, like long-term poverty, can inhibit innovation. But as much research and many real-world examples show, adversity can also stimulate innovation. Indeed, the COVID-19 pandemic provides a number of recent examples where adverse conditions have led individuals, firms, and governments to innovate in the hope of benefiting society. Despite the fact that some forms of adversity undermine innovation while others stimulate it, legal scholars have largely failed to distinguish between the two forms or even account for adversity\u27s relationship to innovation when assessing innovation law and policy, including intellectual property (IP) laws. Yet given adversity\u27s significant role in affecting the pace and direction of innovation, doing so is crucial. In this Article, we undertake that task. Our analysis shows that adversity is most likely to stimulate innovation when it satisfies what we call the Goldilocks principle: the adversity is neither too intense nor too mild, too fleeting nor too enduring, too all-encompassing nor too confined, too commonly experienced nor too isolated, too severe nor too insignificant, but instead is just right. Hence, for adversity to have the best chance of stimulating innovation, it should be (1) a relatively discrete experience; (2) of moderate intensity; (3) experienced collectively rather than in isolation; and (4) significant enough that, if left unaddressed, the adversity could result in severe consequences for large groups of people. To be clear, these conditions are not necessary for innovation- adversity, or some other trigger, might spur innovation even if each of these conditions is not met. Neither are they sufficient-innovation will not necessarily occur even if all of these conditions are present. Indeed, individual and organizational characteristics often play a role in determining whether a party will respond to adversity with innovation. But existing research suggests that these are some of the features of adversity most conducive to, and thus most likely to inspire, innovation. Conversely, adverse conditions falling outside of these parameters are more likely to inhibit innovation, or at least fail to stimulate it. We then assess what this means for IP laws and innovation policy more generally. Predominant theories suggest that IP laws are meant to incentivize parties to benefit society through innovation and creativity. Yet over the years, commentators have pointed out that IP rights are often unnecessary to inspire these activities and thus at times impose unnecessary costs on society by restricting access to those innovations. We contribute to this important discussion by highlighting the role that adverse conditions frequently play in affecting the pace and direction of innovation. First, we argue that the role of certain types of adversity in stimulating innovations provides another reason to doubt the efficacy of IP rights as applied to many of those innovations. Other policy levers, such as grants and prizes, may often be preferable in such cases. Second, we explore possible solutions to innovation-inhibiting adversity, including bolstering IP rights in certain situations and a greater societal commitment to basic research funding. Finally, we examine the role that adversity can play in creating innovation path dependencies, and we briefly explore some possible solutions to this dilemma
Innovation in Adversity
Adverse experiences, like long-term poverty, can inhibit innovation. But as much research and many real-world examples show, adversity can also stimulate innovation. Indeed, the COVID-19 pandemic provides a number of recent examples where adverse conditions have led individuals, firms, and governments to innovate in the hope of benefiting society. Despite the fact that some forms of adversity undermine innovation while others stimulate it, legal scholars have largely failed to distinguish between the two forms or even account for adversity\u27s relationship to innovation when assessing innovation law and policy, including intellectual property (IP) laws. Yet given adversity\u27s significant role in affecting the pace and direction of innovation, doing so is crucial. In this Article, we undertake that task. Our analysis shows that adversity is most likely to stimulate innovation when it satisfies what we call the Goldilocks principle: the adversity is neither too intense nor too mild, too fleeting nor too enduring, too all-encompassing nor too confined, too commonly experienced nor too isolated, too severe nor too insignificant, but instead is just right. Hence, for adversity to have the best chance of stimulating innovation, it should be (1) a relatively discrete experience; (2) of moderate intensity; (3) experienced collectively rather than in isolation; and (4) significant enough that, if left unaddressed, the adversity could result in severe consequences for large groups of people. To be clear, these conditions are not necessary for innovation- adversity, or some other trigger, might spur innovation even if each of these conditions is not met. Neither are they sufficient-innovation will not necessarily occur even if all of these conditions are present. Indeed, individual and organizational characteristics often play a role in determining whether a party will respond to adversity with innovation. But existing research suggests that these are some of the features of adversity most conducive to, and thus most likely to inspire, innovation. Conversely, adverse conditions falling outside of these parameters are more likely to inhibit innovation, or at least fail to stimulate it. We then assess what this means for IP laws and innovation policy more generally. Predominant theories suggest that IP laws are meant to incentivize parties to benefit society through innovation and creativity. Yet over the years, commentators have pointed out that IP rights are often unnecessary to inspire these activities and thus at times impose unnecessary costs on society by restricting access to those innovations. We contribute to this important discussion by highlighting the role that adverse conditions frequently play in affecting the pace and direction of innovation. First, we argue that the role of certain types of adversity in stimulating innovations provides another reason to doubt the efficacy of IP rights as applied to many of those innovations. Other policy levers, such as grants and prizes, may often be preferable in such cases. Second, we explore possible solutions to innovation-inhibiting adversity, including bolstering IP rights in certain situations and a greater societal commitment to basic research funding. Finally, we examine the role that adversity can play in creating innovation path dependencies, and we briefly explore some possible solutions to this dilemma
Small Satellite Regulation in 2020
Small satellite innovation has advanced at a rapid pace over the past decade, but until recently satellite licensing procedures have lagged behind technological innovation, imposing significant regulatory and financial burdens on small satellite operators during early stages of system development. In late 2019, the Federal Communications Commission (FCC) adopted rules creating a new, optional licensing process for small satellites meeting certain criteria, such as a wet mass of 180 kg or less, a shorter in-orbit lifetime, and a low orbital debris risk. Satellite systems meeting these and other criteria may apply for FCC authorization or U.S. market access under a streamlined application process with reduced fees, decreasing barriers to entry for qualifying operators and enabling the deployment of low-cost satellite systems. This new licensing process is in addition to the FCC’s existing processes for satellite authorization, including its experimental (part 5), amateur (part 97), and standard commercial satellite licensing procedures (part 25). Small satellite operators seeking to provide service in the United States now have a variety of licensing options to choose from, and will need to select the licensing procedure that best matches their operational and spectrum needs.
In addition to the FCC, satellite licensing involves a variety of other federal agencies. As part of the FCC authorization process, the FCC will coordinate spectrum use with the National Telecommunications and Information Administration (NTIA). The Federal Aviation Administration (FAA) licenses commercial launch and reentry vehicles well as commercial spaceports. Commercial remote sensing satellites require a license from the National Oceanic and Atmospheric Administration (NOAA). The Departments of Commerce and State license exports of space technology. The Department of State also maintains a registry of U.S. space objects. This paper gives an overview of the licensing and authorization regimes in the United States as they apply to small satellite operations
Least weight and least cost optimisation of a passenger vessel
In the scantling design of a passenger ship, minimum production costminimum weight and maximum moment of inertia (stiffness) are conflicting objectives. For that purpose, recent improvements have been made to the LBR-5 software (French acronym of Stiffened Panels Software”, version 5.0) to optimize the scantling of ship sections by considering production cost, weight and moment of inertia in the optimisation objective function. A real multi-criterion optimisation of a passenger ship is presented in this paper. Results highlight that LBR-5 is competitive software to optimise scantling of ships at very early design stage with management of critical problems studied normally at a later step of the design
- …