2,805 research outputs found
The Double Punch of Law and Technology: Fighting Online Music Piracy or Remaking Copyright in a Digital Age?
For the recording industry the case seems clear. Music sales are down for the third straight year. CD sales are now almost 20% lower than in 2000. Despite their successful campaign against Napster two years ago, online music sharing through peer-to-peer service such as KaZaA and Gnutella continues to flourish. To re-establish its pre-Napster margins, industry thinking goes, the record labels have to put an end to illegal music sharing over the Internet once and for all. Hence, the recent decision by the industry-leading Recording Industry Association of America (RIAA) to take the fight directly to file sharers, not merely to commercial file sharing services
A flight-test methodology for identification of an aerodynamic model for a V/STOL aircraft
Described is a flight test methodology for developing a data base to be used to identify an aerodynamic model of a vertical and short takeoff and landing (V/STOL) fighter aircraft. The aircraft serves as a test bed at Ames for ongoing research in advanced V/STOL control and display concepts. The flight envelope to be modeled includes hover, transition to conventional flight, and back to hover, STOL operation, and normaL cruise. Although the aerodynamic model is highly nonlinear, it has been formulated to be linear in the parameters to be identified. Motivation for the flight test methodology advocated in this paper is based on the choice of a linear least-squares method for model identification. The paper covers elements of the methodology from maneuver design to the completed data base. Major emphasis is placed on the use of state estimation with tracking data to ensure consistency among maneuver variables prior to their entry into the data base. The design and processing of a typical maneuver is illustrated
Storied Discipleship: Nine Practices for Jesus-Shaped Living
This project germinated out of the observation that many evangelical congregations are facing the malaise of a profound lack of true faith formation, which is creating a wide gap between authentic Christ formation and secularization, and is further exacerbated by the genuine blind spot of denial in the minds of Christians that this is problematic. In a distracted and frenzied world, faith formation is becoming less of a priority, which is caused by an inherent bent toward selfish independence. Changing the narrative on these observations would mean Christians prioritize and cultivate their relationship with Jesus Christ, propelling them outwardly towards a selfless interdependence. These observations were made as I peered through the windshield of my ministry context in both a Midwest and West Coast local congregation and farther out into the religious and secular climate of the cultural moment of the years leading up to and through the worldwide Covid-19 pandemic. Storied Discipleship: Nine Practices for Jesus-Shaped Living is the plant that is beginning to grow from these observations. It was born out of the desire to help distracted people refocus their attention on matters of faith and help them begin developing new and healthier habits in their spiritual formation process. The nine practices articulate that disciples of Jesus will find themselves living a praying, learning, caring, blessing, celebrating, sharing, resting, simplifying, and tending life. Each part of this project is designed to assist disciples in evaluating the story they are living, to be captivated by and trust the Jesus-story, to live the Jesus-story out in ever-increasing ways, and to share the story with others
Flight testing a V/STOL aircraft to identify a full-envelope aerodynamic model
Flight-test techniques are being used to generate a data base for identification of a full-envelope aerodynamic model of a V/STOL fighter aircraft, the YAV-8B Harrier. The flight envelope to be modeled includes hover, transition to conventional flight and back to hover, STOL operation, and normal cruise. Standard V/STOL procedures such as vertical takeoff and landings, and short takeoff and landings are used to gather data in the powered-lift flight regime. Long (3 to 5 min) maneuvers which include a variety of input types are used to obtain large-amplitude control and response excitations. The aircraft is under continuous radar tracking; a laser tracker is used for V/STOL operations near the ground. Tracking data are used with state-estimation techniques to check data consistency and to derive unmeasured variables, for example, angular accelerations. A propulsion model of the YAV-8B's engine and reaction control system is used to isolate aerodynamic forces and moments for model identification. Representative V/STOL flight data are presented. The processing of a typical short takeoff and slow landing maneuver is illustrated
EELS investigations of stoichiometric niobium oxides and niobium-based capacitors
A comprehensive electron energy-loss spectroscopy (EELS) study of stoichiometric niobium oxides and niobium was performed in a transmission electron microscope. Numerous EELS features were identified allowing the distinction of different Nb-oxidation states. Optimized sensitivity factors were determined for accurate quantification of the Nb-O system which were applied to nanoscale analysis of solid-electrolyte capacitors with Nb anodes and anodically grown niobium-oxide layers as dielectric
A vanishing theorem for operators in Fock space
We consider the bosonic Fock space over the Hilbert space of transversal
vector fields in three dimensions. This space carries a canonical
representation of the group of rotations. For a certain class of operators in
Fock space we show that rotation invariance implies the absence of terms which
either create or annihilate only a single particle. We outline an application
of this result in an operator theoretic renormalization analysis of Hamilton
operators, which occur in non-relativistic qed.Comment: 14 page
Uniqueness of the ground state in the Feshbach renormalization analysis
In the operator theoretic renormalization analysis introduced by Bach,
Froehlich, and Sigal we prove uniqueness of the ground state.Comment: 10 page
Governing Lipitor and Listerine: the domestic roots of international pharmaceutical and cosmetics re
Technical standards and product regulations increasingly shape international trade patterns, the organization of cross-national production, and global investment flows. This paper examines the evolution of international market regulation in the pharmaceutical- and cosmetics industries over the past three decades. International market regulation of pharmaceuticals and cosmetics poses an intriguing empirical puzzle. Both industries have seen the emergence and subsequent institutionalization of international market regulation over the last three decades.
China´s impact on the global economy: from China price to China standard
China´s entry into the global economy is universally accepted as a defining feature of this new century. Much debate has focused on the impact its economy is having on world market prices, both as producer and consumer. This ´China Price´ effect puts tremendous pressure on Western firms. But China is not just competing on price. Supported by new regulatory institutions, it increasingly influences market rules and technology standards as well. Such Chinese efforts pose a direct challenge to Western competitiveness. While Western firms must adapt to the ´China Price´, countering the ´China Standard´ will require coordination with governments to formulate a countervailing regulatory agenda.
Convergence Rates for Non-Log-Concave Sampling and Log-Partition Estimation
Sampling from Gibbs distributions and
computing their log-partition function are fundamental tasks in statistics,
machine learning, and statistical physics. However, while efficient algorithms
are known for convex potentials , the situation is much more difficult in
the non-convex case, where algorithms necessarily suffer from the curse of
dimensionality in the worst case. For optimization, which can be seen as a
low-temperature limit of sampling, it is known that smooth functions allow
faster convergence rates. Specifically, for -times differentiable functions
in dimensions, the optimal rate for algorithms with function
evaluations is known to be , where the constant can potentially
depend on and the function to be optimized. Hence, the curse of
dimensionality can be alleviated for smooth functions at least in terms of the
convergence rate. Recently, it has been shown that similarly fast rates can
also be achieved with polynomial runtime , where the exponent
is independent of or . Hence, it is natural to ask whether similar rates
for sampling and log-partition computation are possible, and whether they can
be realized in polynomial time with an exponent independent of and . We
show that the optimal rates for sampling and log-partition computation are
sometimes equal and sometimes faster than for optimization. We then analyze
various polynomial-time sampling algorithms, including an extension of a recent
promising optimization approach, and find that they sometimes exhibit
interesting behavior but no near-optimal rates. Our results also give further
insights on the relation between sampling, log-partition, and optimization
problems.Comment: Changes in v2: Minor corrections and formatting changes. Plots can be
reproduced using the code at
https://github.com/dholzmueller/sampling_experiment
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