University of Luxembourg

About: University of Luxembourg is a education organization based out in Luxembourg, Luxembourg. It is known for research contribution in the topics: Population & European union. The organization has 4744 authors who have published 22175 publications receiving 381824 citations.

Machine Learning for Molecular Simulation.

Abstract: Machine learning (ML) is transforming all areas of science. The complex and time-consuming calculations in molecular simulations are particularly suitable for an ML revolution and have already been profoundly affected by the application of existing ML methods. Here we review recent ML methods for molecular simulation, with particular focus on (deep) neural networks for the prediction of quantum-mechanical energies and forces, on coarse-grained molecular dynamics, on the extraction of free energy surfaces and kinetics, and on generative network approaches to sample molecular equilibrium structures and compute thermodynamics. To explain these methods and illustrate open methodological problems, we review some important principles of molecular physics and describe how they can be incorporated into ML structures. Finally, we identify and describe a list of open challenges for the interface between ML and molecular simulation.

Factor substitution and factor-augmenting technical progress in the United States: A normalized supply-side system approach

Abstract: Using a normalized CES function with factor-augmenting technical progress, we estimate a supply-side system of the U.S. economy from 1953 to 1998. Avoiding potential estimation biases that...

Synthesis, Characterization, and Electronic Structure of Single-Crystal SnS, Sn2S3, and SnS2

Abstract: Tin sulfide is being widely investigated as an earth-abundant light harvesting material, but recorded efficiencies for SnS fall far below theoretical limits. We describe the synthesis and characterization of the single-crystal tin sulfides (SnS, SnS2, and Sn2S3) through chemical vapor transport, and combine electronic structure calculations with time-resolved microwave conductivity measurements to shed light on the underlying electrical properties of each material. We show that the coexistence of the Sn(II) and Sn(IV) oxidation states would limit the performance of SnS in photovoltaic devices due to the valence band alignment of the respective phases and the “asymmetry” in the underlying point defect behavior. Furthermore, our results suggest that Sn2S3, in addition to SnS, is a candidate material for low-cost thin-film solar cells.

Data Encryption Standard (DES)

Abstract: Background TheData Encryption Standard (DES) [] has been around for more than  years. During this time, the standard was revised three times: as FIPS-- in , as FIPS-- in , and as FIPS-- in . DES was an outcome of a call for primitives in , which did not result in many serious candidates except for a predecessor of DES, Lucifer [, ] designed by IBM around . It took another year for a joint IBM–NSA effort to turn Lucifer intoDES.The structure of Lucifer was significantly altered: Since the design rationale was never made public and the secret key size was reduced from -bit to -bits, this initially resulted in controversy, and some distrust among the public. After some delay, FIPS- was published by NBS (National Bureau of Standards) – nowNIST (National Institute of Standards and Technology) – on January ,  [] (see [] for a discussion of the standardization process). However, in spite of all the controversy it is hard to underestimate the role of DES []. DES was one of the first commercially developed (as opposed to government developed) ciphers whose structure was fully published. This effectively created a community of researchers who could analyze it and propose their own designs. This led to a wave of public interest in cryptography, from which much of the cryptography as we know it today was born.

Effective inter-component communication mapping in Android with Epicc: an essential step towards holistic security analysis

Abstract: Many threats present in smartphones are the result of interactions between application components, not just artifacts of single components. However, current techniques for identifying inter-application communication are ad hoc and do not scale to large numbers of applications. In this paper, we reduce the discovery of inter-component communication (ICC) in smartphones to an instance of the Interprocedural Distributive Environment (IDE) problem, and develop a sound static analysis technique targeted to the Android platform. We apply this analysis to 1,200 applications selected from the Play store and characterize the locations and substance of their ICC. Experiments show that full specifications for ICC can be identified for over 93% of ICC locations for the applications studied. Further the analysis scales well; analysis of each application took on average 113 seconds to complete. Epicc, the resulting tool, finds ICC vulnerabilities with far fewer false positives than the next best tool. In this way, we develop a scalable vehicle to extend current security analysis to entire collections of applications as well as the interfaces they export.