Last 7 days
Bookmark and Share    
Full Text
Peer Reviewed
See detailMachine learning of accurate energy-conserving molecular force fields
Chmiela, Stefan; Tkatchenko, Alexandre UL; Sauceda, Huziel et al

in Science Advances (2017), 3

Using conservation of energy—a fundamental property of closed classical and quantum mechanical systems— we develop an efficient gradient-domain machine learning (GDML) approach to construct accurate ... [more ▼]

Using conservation of energy—a fundamental property of closed classical and quantum mechanical systems— we develop an efficient gradient-domain machine learning (GDML) approach to construct accurate molecular force fields using a restricted number of samples from ab initio molecular dynamics (AIMD) trajectories. The GDML implementation is able to reproduce global potential energy surfaces of intermediate-sized molecules with an accuracy of 0.3 kcal mol−1 for energies and 1 kcal mol−1 Å−1 for atomic forces using only 1000 conformational geometries for training. We demonstrate this accuracy for AIMD trajectories of molecules, including benzene, toluene, naphthalene, ethanol, uracil, and aspirin. The challenge of constructing conservative force fields is accomplished in our work by learning in a Hilbert space of vector-valued functions that obey the law of energy conservation. The GDML approach enables quantitative molecular dynamics simulations for molecules at a fraction of cost of explicit AIMD calculations, thereby allowing the construction of efficient force fields with the accuracy and transferability of high-level ab initio methods. [less ▲]

Detailed reference viewed: 19 (1 UL)
Full Text
See detailLa fine dell'incoatività
Roelens, Nathalie UL

Presentation (2017)

Detailed reference viewed: 14 (0 UL)
See detailStochastic Thermodynamics for Underdamped Brownian Particles: Equivalent Measures, Reversed Stochastic Processes and Feynman-Kac Techniques
Shayanfard, Kamran UL

Doctoral thesis (2017)

Underdamped stochastic thermodynamics provides a handy tool to study a large class of stochastic processes operating out of equilibrium. Colloidal particles in a laser trap, molecular motors and feedback ... [more ▼]

Underdamped stochastic thermodynamics provides a handy tool to study a large class of stochastic processes operating out of equilibrium. Colloidal particles in a laser trap, molecular motors and feedback processes are some of the prominent examples. In the present work we give a mathematical framework for the study of the thermodynamic properties of these phenomena. We focus on Markovian stochastic processes in continuous time and space, and show how the techniques of equivalent measures combined with stochastic solutions of partial differential equations, obtained through Feynman-Kac formula, can be used to derive exact relations between forward and backward diffusion processes. We prove a theorem which allows us to derive the time evolution of an arbitrary path quantity in a simple and systematic way. We further consider a fairly general underdamped stochastic model, and study its nonequilibrium thermodynamic properties at both single trajectory and average levels. For this model, we establish several integral and detailed fluctuation theorems for thermodynamic quantities such as work and entropy production, amongst others. Some of these theorems directly parallel those already obtained in the context of overdamped and master equations, while others are novel. We also discuss some special cases of our model which are directly related to physical systems such as active Brownian particles, feedback processes and isoenergetic stochastic processes. The formalism we develop, and the general model considered here constitute a unified and extended framework for the study of the thermodynamics of underdamped processes, encompassing several physical systems and applications. [less ▲]

Detailed reference viewed: 16 (6 UL)
Full Text
Peer Reviewed
See detailAdaptive Cloud Radio Access Networks: Compression and Optimization
Vu, Xuan Thang UL; Nguyen, Hieu Duy; Quek, Tony Q.S. et al

in IEEE Transactions on Signal Processing (2017), 65(1), 228-241

Future mobile networks are facing with exponential data growth due to the proliferation of diverse mobile equipment and data-hungry applications. Among promising technology candidates to overcome this ... [more ▼]

Future mobile networks are facing with exponential data growth due to the proliferation of diverse mobile equipment and data-hungry applications. Among promising technology candidates to overcome this problem, cloud radio access network (CRAN) has received much attention. In this work, we investigate the design of fronthaul in C-RAN uplink by focusing on the compression and optimization in fronthaul uplinks based on the statistics of wireless fading channels. First, we derive the system block error rate (BLER) under Rayleigh fading channels. In particular, upper and lower bounds of the BLER union bound are obtained in closed-form. From these bounds, we gain insight in terms of diversity order and limits of the BLER. Next, we propose adaptive compression schemes to minimize the fronthaul transmission rate subject to a BLER constraint. Furthermore, a fronthaul rate allocation is proposed to minimize the system BLER. It is shown that the uniform rate allocation approaches the optimal scheme as the total fronthauls’ bandwidth increases. Lastly, numerical results are presented to demonstrate the effectiveness of our proposed optimizations. [less ▲]

Detailed reference viewed: 19 (10 UL)
Full Text
Peer Reviewed
See detailReceiver and Sender Deniable Functional Encryption
De Caro, Angelo; Iovino, Vincenzo UL; O'Neill, Adam

in IET Information Security (2017)

Deniable encryption, first introduced by Canetti et al. (CRYPTO 1997), allows equivocation of encrypted communication. In this work we generalize its study to functional encryption (FE). Our results are ... [more ▼]

Deniable encryption, first introduced by Canetti et al. (CRYPTO 1997), allows equivocation of encrypted communication. In this work we generalize its study to functional encryption (FE). Our results are summarized as follows: We first put forward and motivate the concept of receiver deniable FE, for which we consider two models. In the first model, as previously considered by O'Neill et al. (CRYPTO 2011) in the case of identity-based encryption, a receiver gets assistance from the master authority to generate a fake secret key. In the second model, there are ``normal'' and ``deniable'' secret keys, and a receiver in possession of a deniable secret key can produce a fake but authentic-looking normal key on its own. In the first model, we show a compiler from any FE scheme for the general circuit functionality to a FE scheme having receiver deniability. In addition we show an efficient receiver deniable FE scheme for Boolean Formulae from bilinear maps. In the second (multi-distributional) model, we present a specific FE scheme for the general circuit functionality having receiver deniability. To our knowledge, a scheme in the multi-distributional model was not previously known even for the special case of identity-based encryption. Finally, we construct the first sender (non-multi-distributional) deniable FE scheme. [less ▲]

Detailed reference viewed: 25 (0 UL)
See detail‘WHAT DO YOU MEAN YOU LOST THE PAST?’ AGENCY, EXPRESSION AND SPECTACLE IN AMATEUR FILMMAKING
Wecker, Danièle UL

Doctoral thesis (2017)

The following thesis presents an examination of privately produced amateur films taken from the Amateur Film Archive in the Centre National d’Audiovisuel in Luxembourg. It analyzes how amateur films ... [more ▼]

The following thesis presents an examination of privately produced amateur films taken from the Amateur Film Archive in the Centre National d’Audiovisuel in Luxembourg. It analyzes how amateur films present a filmic world and examines specific notions of meaning generation without meta-data and original context. Rather than take amateur film as a homogenous genre or practice, this study concentrates on film language. The first part of the following two-fold engagement with these filmic worlds thus identifies the highly differentiated filmic modes that can be read from the images. A filmic mode is related to as a concomitance of style and choice in subject matter. Without original context, these films lose their most important means of meaning generation, namely the recollective narratives that are constructed by the intended audience in the viewing situation. This work operates from a basis of analysis that takes these images as remnants of a visual narration rather than in terms of recollective narratives. It operates from the very simple basis that what was filmed had significance for these filmmakers and how the camera was used can serve as illustration of underlying intentions and motivations—both intended and inadvertent. The first part of this study then focuses on the diversification within the images and reads concomitant cultural codifications that structure representational productions in the private and also analyzes film language as means of self-inscription and self-narration. The second part of this two-fold engagement explores filmic language in terms of a visualization of primordial signifying expression coming-into-being. It relates to amateur film and practice from a basis of primary Becoming rather than a fixed Being. This engagement extends to include the researcher and his/her own background as co-constitutive part of this process of primordial meaning coming-into-being. Film is related to as the opening of a filmic universe that presents its own structures and engagements and not as visualization of a profilmic world from the past. [less ▲]

Detailed reference viewed: 15 (5 UL)
Full Text
Peer Reviewed
See detailPump Efficiency Analysis of Waste Water Treatment Plants: A Data Mining Approach Using Signal Decomposition for Decision Making
Torregrossa, Dario; Hansen, Joachim UL; Cornelissen, Alex et al

in Lecture Notes in Computer Science (2017)

Detailed reference viewed: 4 (1 UL)
Full Text
Peer Reviewed
See detailRäumliche Identifikationen und Identifizierungen in Grenzregionen. Das Beispiel der Großregion SaarLorLux
Wille, Christian UL

E-print/Working paper (2017)

In diesem Beitrag wird die Bedeutung von nationalen Grenzen für räumliche Identitäten in Grenzregionen analysiert. Dafür wird ein mehrdimensionales Analysemodell entwickelt und am Beispiel der Großregion ... [more ▼]

In diesem Beitrag wird die Bedeutung von nationalen Grenzen für räumliche Identitäten in Grenzregionen analysiert. Dafür wird ein mehrdimensionales Analysemodell entwickelt und am Beispiel der Großregion SaarLorLux gefragt, wie die Einwohner den Raum repräsentieren und wie sie ihre alltagskulturellen Praktiken räumlich organisieren. Außerdem werden räumliche Projektionen im politischen Diskurs aufgedeckt und rekonstruiert, inwiefern diese eine Grundlage bilden für Identifizierungsprozesse. Der Beitrag zeigt, dass nationale Grenzen in den Identifikations- und Identifizierungsvorgängen der Einwohner der Großregion SaarLorLux trotz grenzüberschreitender Verflechtungen eine wichtige Rolle spielen, aber nicht zwangsläufig als starre Ordnungskategorien. [less ▲]

Detailed reference viewed: 32 (5 UL)
Full Text
Peer Reviewed
See detailDeepCity: A Feature Learning Framework for Mining Location Check-Ins
Pang, Jun UL; Zhang, Yang

in Proceedings of the 11th International Conference on Web and Social Media (ICWSM'17) (2017)

Detailed reference viewed: 16 (0 UL)
Full Text
Peer Reviewed
See detailParkinson’s Disease-Associated Mutant LRRK2-Mediated Inhibition of miRNA Activity is Antagonized by TRIM32
Gonzalez-Cano, Laura; Menzl, Ingeborg; Tisserand, Johan UL et al

in Molecular Neurobiology (2017)

Detailed reference viewed: 7 (1 UL)
See detailL'incidence des lois de police étrangères sur l'activité bancaire
Kinsch, Patrick UL

in Le banquier luxembourgeois et le droit international privé (2017)

Detailed reference viewed: 5 (0 UL)
Full Text
See detailReNEUAL Model Rules on EU Administrative Procedure
Hofmann, Herwig UL; Craig, Paul; Schneider, Jens-Peter et al

Book published by OUP (2017)

Detailed reference viewed: 4 (0 UL)
Full Text
See detailComparative Perspectives on Administrative Procedure
Hofmann, Herwig UL; Weaver, Russel; Huang, Cheng-Yi et al

Book published by Carolina Academic Press (2017)

Detailed reference viewed: 5 (2 UL)
Full Text
See detailThe European Administrative Space - Some Considerations for the Consequences for Public Law in Europe
Hofmann, Herwig UL

in Koprić, Ivan; Kovač (Eds.) European Administrative Space: Spreading Standards, Building Capacities (2017)

Detailed reference viewed: 4 (1 UL)
See detailAPCGO: Stata module to calculate age-period-cohort effects for the gap between two groups (based on a Blinder-Oaxaca decomposition), including trends for each parameter
Chauvel, Louis UL; Hartung, Anne UL; Bar-Haim, Eyal UL

Computer development (2017)

The apcgo program calculates the blinder-oaxaca decomposition for each periodXage group context and estimates age-period-cohort APC-T (trended) models for the explained and unexplained gap. It provides ... [more ▼]

The apcgo program calculates the blinder-oaxaca decomposition for each periodXage group context and estimates age-period-cohort APC-T (trended) models for the explained and unexplained gap. It provides trended parameters of age, period and cohort effects (The trend in age is set to be the average effect of ageing of cohorts observed in the window of observation); appropriate constraints offer a unique solution and solve the traditional APC identification problem. The user provides a dependent variable, a binary group variable (gap), age and period, and controls from a microdata series of crossectional surveys. [less ▲]

Detailed reference viewed: 12 (2 UL)
See detailGENDER SEGREGATION IN EDUCATION, TRAINING AND THE LABOUR MARKET
Hartung, Anne UL

Speeches/Talks (2017)

Detailed reference viewed: 11 (1 UL)
Full Text
Peer Reviewed
See detailLong-Range Repulsion Between Spatially Confined van der Waals Dimers
Sadhukhan, Mainak UL; Tkatchenko, Alexandre UL

in Physical Review Letters (2017), 118

It is an undisputed textbook fact that nonretarded van der Waals (vdW) interactions between isotropic dimers are attractive, regardless of the polarizability of the interacting systems or spatial ... [more ▼]

It is an undisputed textbook fact that nonretarded van der Waals (vdW) interactions between isotropic dimers are attractive, regardless of the polarizability of the interacting systems or spatial dimensionality. The universality of vdW attraction is attributed to the dipolar coupling between fluctuating electron charge densities. Here, we demonstrate that the long-range interaction between spatially confined vdW dimers becomes repulsive when accounting for the full Coulomb interaction between charge fluctuations. Our analytic results are obtained by using the Coulomb potential as a perturbation over dipole-correlated states for two quantum harmonic oscillators embedded in spaces with reduced dimensionality; however, the long-range repulsion is expected to be a general phenomenon for spatially confined quantum systems. We suggest optical experiments to test our predictions, analyze their relevance in the context of intermolecular interactions in nanoscale environments, and rationalize the recent observation of anomalously strong screening of the lateral vdW interactions between aromatic hydrocarbons adsorbed on metal surfaces. [less ▲]

Detailed reference viewed: 4 (1 UL)