Localization Recall Precision (LRP): A New Performance Metric for Object Detection

Average precision (AP), the area under the recall-precision (RP) curve, is the standard performance measure for object detection. Despite its wide acceptance, it has a number of shortcomings, the most important of which are (i) the inability to distinguish very different RP curves, and (ii) the lack of directly measuring bounding box localization accuracy. In this paper, we propose 'Localization Recall Precision (LRP) Error', a new metric which we specifically designed for object detection. LRP Error is composed of three components related to localization, false negative (FN) rate and false positive (FP) rate. Based on LRP, we introduce the 'Optimal LRP', the minimum achievable LRP error representing the best achievable configuration of the detector in terms of recall-precision and the tightness of the boxes. In contrast to AP, which considers precisions over the entire recall domain, Optimal LRP determines the 'best' confidence score threshold for a class, which balances the trade-off between localization and recall-precision. In our experiments, we show that, for state-of-the-art object (SOTA) detectors, Optimal LRP provides richer and more discriminative information than AP. We also demonstrate that the best confidence score thresholds vary significantly among classes and detectors. Moreover, we present LRP results of a simple online video object detector which uses a SOTA still image object detector and show that the class-specific optimized thresholds increase the accuracy against the common approach of using a general threshold for all classes. At https://github.com/cancam/LRP we provide the source code that can compute LRP for the PASCAL VOC and MSCOCO datasets. Our source code can easily be adapted to other datasets as well.Comment: to appear in ECCV 201

Real-Time Face Pose Estimation from Single Range Images

We present a real-time algorithm to estimate the 3D pose of a previously unseen face from a single range image. Based on a novel shape signature to identify noses in range images, we generate candidates for their positions, and then generate and evaluate many pose hypotheses in parallel using modern graphics processing units (GPUs). We developed a novel error function that compares the input range image to precomputed pose images of an average face model. The algorithm is robust to large pose variations of plusmn90deg yaw, plusmn45deg pitch and plusmn30deg roll rotation, facial expression, partial occlusion, and works for multiple faces in the field of view. It correctly estimates 97.8% of the poses within yaw and pitch error of 15deg at 55.8 fps. To evaluate the algorithm, we built a database of range images with large pose variations and developed a method for automatic ground truth annotation.Engineering and Applied Science

Luminescence emission from forward- and reverse-biased multicrystalline silicon solar cells

We study the emission of light from industrial multicrystalline silicon solar cells under forward and reverse biases. Camera-based luminescence imaging techniques and dark lock-in thermography are used to gain information about the spatial distribution and the energy dissipation at pre-breakdown sites frequently found in multicrystalline silicon solar cells. The pre-breakdown occurs at specific sites and is associated with an increase in temperature and the emission of visible light under reverse bias. Moreover, additional light emission is found in some regions in the subband-gap range between 1400 and 1700 nm under forward bias. Investigations of multicrystalline silicon solar cells with different interstitial oxygen concentrations and with an electron microscopic analysis suggest that the local light emission in these areas is directly related to clusters of oxygen. © 2009 American Institute of Physics

The quest for companions to post-common envelope binaries. II. NSVS14256825 and HS0705+6700

We report new mid-eclipse times of the two close binaries NSVS14256825 and HS0705+6700, harboring an sdB primary and a low-mass main-sequence secondary. Both objects display clear variations in the measured orbital period, which can be explained by the action of a third object orbiting the binary. If this interpretation is correct, the third object in NSVS14256825 is a giant planet with a mass of roughly 12 M_Jup. For HS0705+6700, we provide evidence that strengthens the case for the suggested periodic nature of the eclipse time variation and reduces the uncertainties in the parameters of the brown dwarf implied by that model. The derived period is 8.4 yr and the mass is 31 M_Jup, if the orbit is coplanar with the binary. This research is part of the PlanetFinders project, an ongoing collaboration between professional astronomers and student groups at high schools.Comment: Accepted by Astron. and Astrophy

Квазичастицы в квазиклассическом приближении двумерного уравнения типа Хартри

Semiclassical asymptotics have been constructed for the two-dimensional Hartree type equation. The dynamics of the initial state, which is the superposition of two wave packets, has been studied. The constructed solution has been interpreted as an interaction of two quasiparticles to the semiclassical approximation. Equations, describing the dynamics of quasiparticles, have been obtained

Multivariate analysis of 3D ToF-SIMS images: method validation and application to cultured neuronal networks

Advanced data analysis tools are crucial for the application of ToF-SIMS analysis to biological samples. Here, we demonstrate that by using a training set approach principal components analysis (PCA) can be performed on large 3D ToF-SIMS images of neuronal cell cultures. The method readily provides access to sample component information and significantly improves the images’ signal-to-noise ratio (SNR)

Acceptability and feasibility of peer assisted supervision and support for intervention practitioners: a Q-methodology evaluation

Evidence-based interventions often include quality improvement methods to support fidelity and improve client outcomes. Clinical supervision is promoted as an effective way of developing practitioner confidence and competence in delivery; however, supervision is often inconsistent and embedded in hierarchical line management structures that may limit the opportunity for reflective learning. The Peer Assisted Supervision and Support (PASS) supervision model uses peer relationships to promote the self-regulatory capacity of practitioners to improve intervention delivery. The aim of the present study was to assess the acceptability and feasibility of PASS amongst parenting intervention practitioners. A Q-methodology approach was used to generate data and 30 practitioners volunteered to participate in the study. Data were analyzed and interpreted using standard Q-methodology procedures and by-person factor analysis yielded three factors. There was consensus that PASS was acceptable. Participants shared the view that PASS facilitated an environment of support where negative aspects of interpersonal relationships that might develop in supervision were not evident. Two factors represented the viewpoint that PASS was also a feasible model of supervision. However, the third factor was comprised of practitioners who reported that PASS could be time consuming and difficult to fit into existing work demands. There were differences across the three factors in the extent to which practitioners considered PASS impacted on their intervention delivery. The findings highlight the importance of organizational mechanisms that support practitioner engagement in supervision

Strukturelle Organisation des alveolaren Surfactant:Tensiometrische und oberflächenmassenspektrometrische Untersuchungen zur Lipidspezifität des Surfactant Protein B

Der pulmonale Surfactant wird durch alveolare Typ II Pneumozyten sekretiert und bildet an der Luft/Wasser-Grenzfläche ein Multischichtsystem aus. Besteht das neu sekretierte Material neben einigen Proteinen aus einer Vielzahl unterschiedlicher Lipid-Komponenten, so ist das Multischichtsystem vermutlich angereichert mit Dipalmitoylphosphatidylcholin (DPPC). Für diesen Anreicherungsprozess sind die Surfactant Proteine verantwortlich, denen eine Spezifität für bestimmte Lipide zugesprochen wird. Ziel der vorliegenden Arbeit war es zu prüfen, ob das Surfactant Protein B (SP-B) spezifisch mit dem Lipid Phosphatidylglycerol wechselwirkt. Die Ergebnisse, die im Rahmen der vorliegenden Arbeit mit Hilfe der Sekundärionenmassenspektrometrie und der Captive Bubble Surfactometrie erzielt wurden, sprechen gegen diese Grundannahme. Sie legen vielmehr nahe, dass SP-B spezifisch mit DPPC wechselwirkt

Persistent decay of fresh xylem hydraulic conductivity varies with pressure gradient and marks plant responses to injury

Defining plant hydraulic traits is central to the quantification of ecohydrological processes ranging from land-atmosphere interactions, to tree mortality, and water-carbon budgets. A key plant trait is the xylem specific hydraulic conductivity (Kx ), that describes the plant's vascular system capacity to transport water. While xylem's vessels and tracheids are dead upon maturity, the xylem is neither inert nor deadwood, various components of the sapwood and surrounding tissue remaining alive and functional. Moreover, the established definition of Kx assumes linear relations between water flux and pressure gradient by tacitly considering the xylem as a "passive conduit". Here we reexamine this notion of an inert xylem by systematically characterizing xylem flow in several woody plants using Kx measurements under constant and cyclic pressure gradients. Results show a temporal and pressure gradient dependence of Kx . Additionally, microscopic features in "living branches" are irreversibly modified upon drying of the xylem thus differentiating the macroscopic definition of Kx for living and dead xylem. The findings highlight the picture of the xylem as a complex and delicate conductive system whose hydraulic behavior transcends a passive gradient-based flow. The study sheds new light on xylem conceptualization, conductivity measurement protocols, in situ long-distance water transport, and ecosystem modeling. This article is protected by copyright. All rights reserved