Grid Loss: Detecting Occluded Faces

Detection of partially occluded objects is a challenging computer vision problem. Standard Convolutional Neural Network (CNN) detectors fail if parts of the detection window are occluded, since not every sub-part of the window is discriminative on its own. To address this issue, we propose a novel loss layer for CNNs, named grid loss, which minimizes the error rate on sub-blocks of a convolution layer independently rather than over the whole feature map. This results in parts being more discriminative on their own, enabling the detector to recover if the detection window is partially occluded. By mapping our loss layer back to a regular fully connected layer, no additional computational cost is incurred at runtime compared to standard CNNs. We demonstrate our method for face detection on several public face detection benchmarks and show that our method outperforms regular CNNs, is suitable for realtime applications and achieves state-of-the-art performance.Comment: accepted to ECCV 201

Controlling the Spin of Co Atoms on Pt(111) by Hydrogen Adsorption

We investigate the effect of H adsorption on the magnetic properties of individual Co atoms on Pt(111) with scanning tunneling microscopy. For pristine Co atoms, we detect no inelastic features in the tunnel spectra. Conversely, CoH and CoH2 show a number of low-energy vibrational features in their differential conductance identified by isotope substitution. Only the fcc-adsorbed species present conductance steps of magnetic origin, with a field splitting identifying their effective spin as S-eff = 2 for CoH and 3/2 for CoH2. The exposure to H-2 and desorption through tunnel electrons allow the reversible control of the spin in half-integer steps. Because of the presence of the surface, the hydrogen-induced spin increase is opposite to the spin sequence of CoHn molecules in the gas phase

Interlayer exchange coupling in ordered Fe nanocluster arrays grown on Al2O3/Ni3Al(111)

We have combined magneto-optical Kerr effect, scanning tunneling microscopy, and x-ray magnetic circular dichroism to study the magnetic properties and the morphology of Fe nanoparticles grown on 2 ML thick Al2O3/Ni3Al(111)-(root 67 x root 67)R12.2 degrees with and without Pd seeding. The Ni3Al(111) substrate is ferromagnetic and shows two transition temperatures. The first, T-C1 = 81 +/- 3 K, is attributed to a 20-30 nm thick slightly Ni enriched region; the second, T-C2 = 240 +/- 12 K, is attributed to a much thinner and more strongly Ni enriched near interface region that contains Ni clusters embedded in the alloy matrix. The magnetic properties of the Fe cluster superlattice are strongly influenced by the superexchange coupling between Fe clusters and the underlying Ni clusters in that near interface region. Since the Ni clusters are at different distances from the oxide/metal interface, this coupling oscillates between ferro-and antiferromagnetic such that the overall magnetic moment is not increased by the Fe clusters. Pd seeding does not influence the magnetic properties of the system. The intrinsic Fe cluster properties, such as Curie temperature and easy magnetization axis, are accessed for T > T-C2. We find out-of-plane easy magnetization axes and T-C approximate to 300 K for cluster sizes above 440 atoms

Tailoring the Magnetism of Co Atoms on Graphene through Substrate Hybridization

We determine the magnetic properties of individual Co atoms adsorbed on graphene (G) with x-ray absorption spectroscopy and magnetic circular dichroism. The magnetic ground state of Co adatoms strongly depends on the choice of the metal substrate on which graphene is grown. Cobalt atoms on G/Ru(0001) feature exceptionally large orbital and spin moments, as well as an out-of-plane easy axis with large magnetic anisotropy. Conversely, the magnetic moments are strongly reduced for Co/G/Ir(111), and the magnetization is of the easy-plane type. We demonstrate how the Co magnetic properties, which ultimately depend on the degree of hybridization between the Co 3d orbitals and graphene p bands, can be tailored through the strength of the graphene-substrate coupling

The ECHR and the Principle of Non-discrimination

The book examines the evolution of the interpretation of Article 14 ECHR and the related case law of the European Court of Human Rights. It reunites experts in this field who investigated the topic horizontally and in relation to specific groups or rights