Vertical versus conical square functions

We study the difference between vertical and conical square functions in the abstract and also in the specific case where the square functions come from an elliptic operator.Comment: 21 page

Riesz transform on manifolds and heat kernel regularity

One considers the class of complete non-compact Riemannian manifolds whose heat kernel satisfies Gaussian estimates from above and below. One shows that the Riesz transform is $L^p$ bounded on such a manifold, for $p$ ranging in an open interval above 2, if and only if the gradient of the heat kernel satisfies a certain $L^p$ estimate in the same interval of $p$'s.Comment: to appear in Annales de l'Ecole Normale Superieure de Pari

Carleson measures, trees, extrapolation, and T(b)T(b) theorems

The theory of Carleson measures, stopping time arguments, and atomic decompositions has been well-established in harmonic analysis. More recent is the theory of phase space analysis from the point of view of wave packets on tiles, tree selection algorithms, and tree size estimates. The purpose of this paper is to demonstrate that the two theories are in fact closely related, by taking existing results and reproving them in a unified setting. In particular we give a dyadic version of extrapolation for Carleson measures, with two separate proofs, as well as a two-sided local dyadic $T(b)$ theorem which generalizes earlier $T(b)$ theorems of David, Journe, Semmes, and Christ.Comment: 50 pages, 3 figures, to appear, Publications Matematiques Barcelona. A new proof of the extrapolation lemma (due to John Garnett) is now include

Learning Aerial Image Segmentation from Online Maps

This study deals with semantic segmentation of high-resolution (aerial) images where a semantic class label is assigned to each pixel via supervised classification as a basis for automatic map generation. Recently, deep convolutional neural networks (CNNs) have shown impressive performance and have quickly become the de-facto standard for semantic segmentation, with the added benefit that task-specific feature design is no longer necessary. However, a major downside of deep learning methods is that they are extremely data-hungry, thus aggravating the perennial bottleneck of supervised classification, to obtain enough annotated training data. On the other hand, it has been observed that they are rather robust against noise in the training labels. This opens up the intriguing possibility to avoid annotating huge amounts of training data, and instead train the classifier from existing legacy data or crowd-sourced maps which can exhibit high levels of noise. The question addressed in this paper is: can training with large-scale, publicly available labels replace a substantial part of the manual labeling effort and still achieve sufficient performance? Such data will inevitably contain a significant portion of errors, but in return virtually unlimited quantities of it are available in larger parts of the world. We adapt a state-of-the-art CNN architecture for semantic segmentation of buildings and roads in aerial images, and compare its performance when using different training data sets, ranging from manually labeled, pixel-accurate ground truth of the same city to automatic training data derived from OpenStreetMap data from distant locations. We report our results that indicate that satisfying performance can be obtained with significantly less manual annotation effort, by exploiting noisy large-scale training data.Comment: Published in IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSIN

Absence of superconductivity in ultra-thin layers of FeSe synthesized on a topological insulator

The structural and electronic properties of FeSe ultra-thin layers on Bi$_{2}$Se$_{3}$ have been investigated with a combination of scanning tunneling microscopy and spectroscopy and angle-resolved photoemission spectroscopy. The FeSe multi-layers, which are predominantly 3-5 monolayers (ML) thick, exhibit a hole pocket-like electron band at \bar{\Gamma} and a dumbbell-like feature at \bar{M}, similar to multi-layers of FeSe on SrTiO$_{3}$. Moreover, the topological state of the Bi2Se3 is preserved beneath the FeSe layer, as indicated by a heavily \it{n}-doped Dirac cone. Low temperature STS does not exhibit a superconducting gap for any investigated thickness down to a temperature of 5 K

The local structure of molecular reaction intermediates at surfaces

A critical review is presented of the results of (experimental) quantitative structural studies of molecular reaction intermediates at surfaces; i.e. molecular species that do not exist naturally in the gas phase and, in most cases, are implicated in surface catalytic processes. A brief review of the main experimental methods that have contributed to this area is followed by a summary of the main results. Investigated species include: carboxylates, RCOO– (particularly formate, but also deprotonated amino acids); methoxy, CH3O–; carbonate, CO3; ethylidyne, CH3C–; NHx and SOx species; cyanide, CN. As far as possible in the limited range of systems studied, a few general trends are identified

Reporting in Large‑Scale Agile Organizations : Insights And Recommendations From a Case Study in Software Development

Abstract Application of agile software development methodologies in large-scale organizations is becoming increasingly common. However, working with multiple teams and on multiple products at the same time yields higher coordination and communication efforts compared to single-team settings for which agile methodologies have been designed originally. With the introduction of agile methodologies at scale also comes the need to be able to report progress and performance not only of individual teams but also on higher aggregation of products and portfolios. Due to faster iterations, production of intermediate work results, increased autonomy of teams, and other novel characteristics, agile methodologies are challenging existing reporting approaches in large organizations. Based on 23 interviews with 17 practitioners from a large German car manufacturing company, this case study investigates challenges with reporting in large-scale agile settings. Further, based on insights from the case study, recommendations are derived. We find that combining reporting and agile methodologies in large-scale settings is indeed challenging in practice. Our research contributes to the understanding of these challenges, and points out opportunities for future research to improve reporting in large-scale agile organizations by goal-setting and automation

Linking Mine Action and SSR through Human Security

Security sector reform (SSR) and mine action share a strong common conceptual basis, which draws from a shared understanding of security. They both reflect a conceptualization of security that is not limited to the level of the state, but takes into account security threats and needs at societal and individual levels. This common basis provides opportunities for synergies between SSR and mine action. However, empirical evidence demonstrates that the strong conceptual basis is not fully reflected in concrete activities, and the linkages remain limited and underexplored. Despite this gap, there are positive examples showing the potential for synergies between SSR and mine action. Ultimately, this paper maintains that the concept of human security provides a comprehensive framework which can bridge the differences and open broader opportunities for cooperation, which in turn will increase the impact of interventions in SSR and mine action

Pilot testing methodologies, models, scenarios and validation approach

This report describes the pilot tests that will be carried out within GARPUR. The pilot tests aim at assessing and validating, as closely as possible to real-life conditions, the new Reliability Management Approach and Criteria (RMACs) developed in work package 2 and the socio-economic impact assessment framework developed in work package 3, while considering the methodologies and approaches for practical implementation in work packages 4, 5 and 6. The proposed RMACs are compared against the current N-1 practices and approaches determined in work package 1. In addition, some pilot tests will make use of the GARPUR Quantification Platform (GQP) that has been developed by work package 7. A total of eight pilot tests are proposed by five different transmission system operators (TSOs) and given different priority levels for implementation. Three pilot tests make use of the GQP. The five other pilot tests will be implemented at TSOs’ premises in near real-life context. The pilot tests cover real-time operations, short-term operation planning and long-term system development. Different indicators are proposed to assess the proposed reliability management approach and criteria and compare them with current practices. The diversity of the pilot tests in terms of time horizons and the number of involved TSOs demonstrate the general nature of the reliability management approach and criteria proposed within GARPUR