Atomic-scale representation and statistical learning of tensorial properties

This chapter discusses the importance of incorporating three-dimensional symmetries in the context of statistical learning models geared towards the interpolation of the tensorial properties of atomic-scale structures. We focus on Gaussian process regression, and in particular on the construction of structural representations, and the associated kernel functions, that are endowed with the geometric covariance properties compatible with those of the learning targets. We summarize the general formulation of such a symmetry-adapted Gaussian process regression model, and how it can be implemented based on a scheme that generalizes the popular smooth overlap of atomic positions representation. We give examples of the performance of this framework when learning the polarizability and the ground-state electron density of a molecule

Sage‐Grouse Breeding and Late Brood‐Rearing Habitat Guidelines in Utah

Delineation, protection, and restoration of habitats provide the basis for endangered and threatened species recovery plans. Species recovery plans typically contain guidelines that provide managers with a scientific basis to designate and manage critical habitats. As such, habitat guidelines are best developed using data that capture the full diversity of ecological and environmental conditions that provide habitat across the species’ range. However, when baseline information, which fails to capture habitat diversity, is used to develop guidelines, inconsistencies and problems arise when applying those guidelines to habitats within an ecologically diverse landscape. Greater sage‐grouse (Centrocercus urophasianus; sage‐ grouse) populations in Utah, USA, reflect this scenario—published range‐wide habitat guidelines developed through a literature synthesis did not include data from the full range of the species. Although all sage‐ grouse are considered sagebrush obligates (Artemisia spp.), the species occupies a diversity of sagebrush communities from shrub‐dominated semideserts in the southwest to more perennial grass‐dominated sagebrush‐steppe in the northeast portions of their distribution. Concomitantly, local ecological site and environmental conditions may limit the ability of managers to achieve broader range‐wide habitat guidelines. We combined microsite habitat vegetation parameters from radiomarked sage‐grouse nest and brood locations with state‐wide spatially continuous vegetation, climatic, and elevation data in a cluster analysis to develop empirically based sage‐grouse habitat guidelines that encompass the range of ecological and environmental variation across Utah. Using this novel approach, we identified 3 distinct clusters of sage‐grouse breeding (i.e., nesting and early brood‐rearing) and late brood‐rearing habitats in Utah. For each cluster, we identified specific vegetation recommendations that managers can use to assess sage‐grouse breeding and late brood‐rearing habitat. Our results provide relevant guidelines to Utah’s sage‐grouse populations and are feasible given the unique ecological variation found therein. This approach may have application to other species that occupy diverse habitats and physiographic regions

An unfolding signifier: London's Baltic Exchange in Tallinn

In the summer of 2007 an unusual cargo arrived at Muuga and Paldiski harbors outside Tallinn. It consisted of nearly 50 containers holding over 1,000 tons of building material ranging from marble columns, staircases and fireplaces, to sculpted allegorical figures, wooden paneling and old-fashioned telephone booths. They were once part of the Baltic Exchange in the City of London. Soon they will become facets of the landscape of Tallinn. The following article charts this remarkable story and deploys this fragmented monument to analyze three issues relating to the Estonian capital: the relocation of the ‘Bronze Soldier’, the demolition of the Sakala Culture Center, and Tallinn’s future role as European Cultural Capital in 2011

Coplanar Waveguide Resonators for Circuit Quantum Electrodynamics

We have designed and fabricated superconducting coplanar waveguide resonators with fundamental frequencies from 2 to $9 \rm{GHz}$ and loaded quality factors ranging from a few hundreds to a several hundred thousands reached at temperatures of $20 \rm{mK}$. The loaded quality factors are controlled by appropriately designed input and output coupling capacitors. The measured transmission spectra are analyzed using both a lumped element model and a distributed element transmission matrix method. The experimentally determined resonance frequencies, quality factors and insertion losses are fully and consistently characterized by the two models for all measured devices. Such resonators find prominent applications in quantum optics and quantum information processing with superconducting electronic circuits and in single photon detectors and parametric amplifiers.Comment: 8 pages, 8 figures, version with high resolution figures available at http://qudev.ethz.ch/content/science/PubsPapers.htm

Local piezoresponse and polarization switching in nucleobase thymine microcrystals

Thymine (2-oxy-4-oxy-5 methyl pyrimidine) is one of the four nucleobases of deoxyribonucleic acid (DNA). In the DNA molecule, thymine binds to adenine via two hydrogen bonds, thus stabilizing the nucleic acid structure and is involved in pairing and replication. Here, we show that synthetic thymine microcrystals grown from the solution exhibit local piezoelectricity and apparent ferroelectricity, as evidenced by nanoscale electromechanical measurements via Piezoresponse Force Microscopy. Our experimental results demonstrate significant electromechanical activity and polarization switchability of thymine, thus opening a pathway for piezoelectric and ferroelectric-based applications of thymine and, perhaps, of other DNA nucleobase materials. The results are supported by molecular modeling of polarization switching under an external electric field. (C) 2015 AIP Publishing LLC

Maintenance and refurbishment planning for a group of bridges

During the service, highway overpasses are exposed to various deterioration processes. The rate of these unavoidable processes depends on intensity of usage, weather influences and maintenance level. If maintenance works are not planned and executed in an adequate manner, the performance of the structures under consideration reduces. Planning an optimum set of intervention measures on the level of a group of structures is a complex task that is often left to subjective, partial decisions of managers that have to take int the account also financial limitations.\ud A group of 27 highway overpasses, spanning over the highway section under consideration, was analysed. A multi-criteria model for the selection of bridges that should have priority in the refurbishment process was developed. Condition rating data were collected from the periodic check\ud reports and and structured appropriately. Key criteria that need to be taken into the account were identified: condition ration of the whole structure, age of the pass, possibility of joining the works on a string of passes, indirect cost influence, refurbishment cost for a structure and deterioraton rate of the structure. Relative importance among these citeria was determined by using Analytical Hierarchy Method (AHP). On this basis, a multi-criteria model to be used for the selection of a set of structures\ud that have refurbishment priority in the case of limited financial contribution was developed. Refurbishment priority was identified for a group of structures that have, as a whole, a maximum overall benefit with respect to the selected criteria and their relative importance. Further, the analysis of the influence of the financial constraint magnitude upon the selection of structures to be repaired and the accompanying benefits ( that can facilitate the decision of the decision-makers' side) was carried out. The obtained results show that the proposed model can serve as an efficient tool used in rational selection of group of structures yielding the maximum overall benefit, and in analysis of possibilitie that lead to additional benefit with minimum financial input

Compendium of Single Event Effects for Candidate Spacecraft Electronics for NASA

We present the results of single events effects (SEE) testing and analysis investigating the effects of radiation on electronics

"I am NN": A Reconstruction of Anscombe's "The First Person"

This paper develops a way of understanding G.E.M. Anscombe’s essay “The First Person”, at the heart of which are the following two ideas: first, that the point of her essay is to show that it is not possible for anyone to understand what they express with “I” as an Art des Gegebenseins—a way of thinking of an object that constitutes identifying knowledge of which object is being thought of; and second, that the argument through which her essay seeks to show this is itself first personal in character. Understanding Anscombe’s essay in this light has the merit of showing much of what it says to be correct. But it sets us the task of saying what it is that we understand ourselves to express with “I” if not an Art des Gegebenseins, and in particular what it is that we understand ourselves to express with sentences with “I” as subject that might seem to express identity-judgments, such as “I am NN”, and “I am this body”