24,829 research outputs found
Fairplay or Greed: Mandating University Responsibility Toward Student Inventors
Over twenty years have passed since the enactment of The Patent and Trademark Law Amendments Act (Bayh-Dole Act) and universities continue to struggle with their technology transfer infrastructures. Lost in that struggle are those who could be considered the backbone of university research: the students. Graduate and undergraduate students remain baffled by the patent assignment and technology transfer processes within their various institutions. Efforts should be undertaken by universities to clarify the student\u27s position in the creative process
Multigrid waveform relaxation for the time-fractional heat equation
In this work, we propose an efficient and robust multigrid method for solving
the time-fractional heat equation. Due to the nonlocal property of fractional
differential operators, numerical methods usually generate systems of equations
for which the coefficient matrix is dense. Therefore, the design of efficient
solvers for the numerical simulation of these problems is a difficult task. We
develop a parallel-in-time multigrid algorithm based on the waveform relaxation
approach, whose application to time-fractional problems seems very natural due
to the fact that the fractional derivative at each spatial point depends on the
values of the function at this point at all earlier times. Exploiting the
Toeplitz-like structure of the coefficient matrix, the proposed multigrid
waveform relaxation method has a computational cost of
operations, where is the number of time steps and is the number of
spatial grid points. A semi-algebraic mode analysis is also developed to
theoretically confirm the good results obtained. Several numerical experiments,
including examples with non-smooth solutions and a nonlinear problem with
applications in porous media, are presented
The Cost of Job Security Regulation: Evidence from Latin American Labor Markets
This paper documents the high level of job security protection in Latin American labor markets and analyzes its impact on employment. We show that job security policies have substantial impact on the level and the distribution of employment in Latin America. They reduce employment and promote inequality. The institutional organization of the labor market affects both employment and inequality.
Variational Matrix Product Operators for the Steady State of Dissipative Quantum Systems
We present a new variational method, based on the matrix product operator
(MPO) ansatz, for finding the steady state of dissipative quantum chains
governed by master equations of the Lindblad form. Instead of requiring an
accurate representation of the system evolution until the stationary state is
attained, the algorithm directly targets the final state, thus allowing for a
faster convergence when the steady state is a MPO with small bond dimension.
Our numerical simulations for several dissipative spin models over a wide range
of parameters illustrate the performance of the method and show that indeed the
stationary state is often well described by a MPO of very moderate dimensions.Comment: Accepted versio
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