Temporal Smoothing for Joint Probabilistic People Detection in a Depth Sensor Network

Wide-area indoor people detection in a network of depth sensors is the basis for many applications, e.g. people counting or customer behavior analysis. Existing probabilistic methods use approximative stochastic inference to estimate the marginal probability distribution of people present in the scene for a single time step. In this work we investigate how the temporal context, given by a time series of multi-view depth observations, can be exploited to regularize a mean-field variational inference optimization process. We present a probabilistic grid based dynamic model and deduce the corresponding mean-field update regulations to effectively approximate the joint probability distribution of people present in the scene across space and time. Our experiments show that the proposed temporal regularization leads to a more robust estimation of the desired probability distribution and increases the detection performance

Joint Probabilistic People Detection in Overlapping Depth Images

Privacy-preserving high-quality people detection is a vital computer vision task for various indoor scenarios, e.g. people counting, customer behavior analysis, ambient assisted living or smart homes. In this work a novel approach for people detection in multiple overlapping depth images is proposed. We present a probabilistic framework utilizing a generative scene model to jointly exploit the multi-view image evidence, allowing us to detect people from arbitrary viewpoints. Our approach makes use of mean-field variational inference to not only estimate the maximum a posteriori (MAP) state but to also approximate the posterior probability distribution of people present in the scene. Evaluation shows state-of-the-art results on a novel data set for indoor people detection and tracking in depth images from the top-view with high perspective distortions. Furthermore it can be demonstrated that our approach (compared to the the mono-view setup) successfully exploits the multi-view image evidence and robustly converges in only a few iterations

People Detection in a Depth Sensor Network via Multi-View CNNs trained on Synthetic Data

In this work an approach for wide-area indoor people detection with a network of depth sensors is presented. We propose an end-to-end multi-view deep learning architecture which takes three foreground segmented overlapping depth images as input and predicts the marginal probability distribution of people present in the scene. In contrast to classical data-driven approaches our method does not make use of any real image data for training but uses a randomized generative scene model to generate synthetic depth images which are used to train our proposed deep learning architecture. The evaluation shows promising results on a publicly available data set

Communication and signal exchange in the Rhizobium bradyrhizobium legume system

A new comprehensive communication concept in the Rhizobium/Bradyrhizobium legume symbiosis was developed. It includes a root zone specific flavonoid exudation, the differential activity of phenylpropane/acetate pathway derivatives on chemotaxis, nod-gene inducing activity and phytoalexin resistance induction on the microsymbiont side (Bradyrhizobium). Nod factor production from the microsymbiont affects the host plant in root hair curling and meristem induction. Phytoalexin production in the host plant is also an early response, however repressed to a low level after a few hours. Another strategy of the microsymbiont to overcome phytoalexin effects is degradation of phytoalexins in Rhizobium leguminosarum bv. vicieae. Competitiveness within the same infection group of the microsymbiont was studied with gus-gene fusion, using the blue coloured nodules to easily discriminate marked strains from unmarked competitors. New exopolysaccharide (EPS) mutants of Bradyrhizobium japonicum were reconstructed homologous with a DNA region to exoB gene of Rhizobium meliloti. Their clearly reduced competitiveness of nodulation, demonstrates that exopolysaccharides of Bradyrhizohium japonicum also have an important function during the early stages of this symbiotic interaction

Predicting the binary black hole population of the Milky Way with cosmological simulations

Binary black holes are the primary endpoint of massive stellar evolution. Their properties provide a unique opportunity to constrain binary evolution, which is still poorly understood. In this paper, we predict the inventory of binary black holes and their merger products in/around the Milky Way, and detail their main properties. We present the first combination of a high-resolution cosmological simulation of a Milky Way-mass galaxy with a binary population synthesis model. The hydrodynamic simulation, taken from the FIRE project, provides a cosmologically realistic star formation history for the galaxy and its stellar halo and satellites. We apply a metallicity-dependent evolutionary model to the star particles to produce individual binary black holes. We find that a million binary black holes have merged in the model Milky Way, and 3 million binaries are still present, with an average mass of 28 Msun per binary. Because the black hole progenitors are biased towards low metallicity stars, half reside in the stellar halo and satellites and 40 per cent of the binaries were formed outside the main galaxy. This trend increases with the masses of the black holes. The numbers and mass distribution of the merged systems is compatible with the LIGO/Virgo detections. Observations of these black holes will be challenging, both with electromagnetic methods and LISA. We find that a cosmologically realistic star formation history, with self-consistent metal enrichment and Galactic accretion history, are key ingredients for determining binary black hole rates that can be compared with observations to constrain massive binary evolution.Comment: accepted in MNRAS, data available at https://fire.northwestern.edu/data

The impact of COVID-19 pandemic on mental burden and quality of life in physicians: Results of an online survey

BackgroundIn previous pan-/epidemics such as the SARS epidemic of 2002/2003, negative effects on the wellbeing and an increase in symptoms of depression and anxiety were observed in doctors due to social isolation and the threat they experienced. Therefore, it is feared that the COVID-19 pandemic will also have a negative impact on the mental health and quality of life of doctors.ObjectiveThe impact of the COVID-19 pandemic on the mental health of physicians. In particular, on the subjective anxiety and burden, depression and quality of life for the total sample and subsamples (work in COVID-19 units vs. no work in COVID-19 units).Materials and methodsIn an online survey, 107 physicians (23–42 years) were asked about their mental health during the COVID-19 pandemic. In addition to socio-demographic data, pandemic- and work-related data were also included. For example, infection control measures, deployment on COVID-19 wards and the subjective perceived threat posed by the pandemic. The physicians were asked to rate their perceived anxiety and stress, retrospectively, at 7 different points in time during the pandemic. The Hospital Anxiety and Depression Scale (HADS) was used to retrospectively assess symptoms of anxiety and depression before and after the onset of the pandemic. The quality of life of the participants after 2 years of the pandemic was assessed using the WHO Quality of Life (WHOQOL-BREF).ResultsBoth subjective anxiety and burden showed wave-like patterns with higher scores in autumn, winter and spring. We observed significant differences between the seven measurement time points for anxiety [Chi2(6) = 197.05, p < 0.001] as well as for burden [Chi2(6) = 106.33, p < 0.001]. Symptoms of depression and anxiety increased significantly during the COVID-19 pandemic (M = 14.16, SD = 7.83) compared to the pre-pandemic time [M = 7.31, SD = 5.14, t(106) = −10.67, p < 0.001]. Physicians who worked at COVID-19 units showed higher scores in quality of life related to social relationships (M = 70.39, SD = 17.69) than physicians not working at COVID-19 units [M = 61.44, SD = 24.55, t(90.14) = −2.145, p = 0.035]. The multi-factorial ANOVA showed that previous psychiatric illness (p < 0.001), greater difference in depression scores (p = 0.014), higher anxiety scores (p = 0.048) and less work experience (p = 0.032) led to lower quality of life.ConclusionHospitals should offer specific support, such as supervision, to prevent the development of longer-term psychiatric sequelae likely to lead to sick leave and high costs for the healthcare system.Trial registrationThe study has been registered at the German Clinical Trials Registry (DRKS-ID: DRKS00028984)

Digital Collages and Aesthetic-Communicative Networking: Insights into a Workshop of the NFKB Research Cluster Interaction and Participation

Dieser Beitrag dokumentiert Eindrücke, Beobachtungen und Ergebnisse aus einem Online-Workshop des Forschungsclusters «Interaktion und Partizipation in der Kulturellen Bildung», der die Vorstellung von Themen, Arbeitsweisen und Prinzipien des Forschungsclusters zum Ziel hatte. Dabei lag es nahe, die Auseinandersetzung selbst interaktiv und partizipativ sowie entlang der Thematik der rahmenden Tagung zu konzipieren. Ein Grossteil der Kommunikation wird hierfür parallel zur Videokonferenz auf ein digitales Whiteboard verlagert, auf dem alle Teilnehmenden individuell und gemeinsam agieren können. Als Material liegen zentrale Fragmente aus einem Text des Clusters bereit, in dem die Begriffe Interaktion und Partizipation in einem gemeinsamen Selbstversuch und geleitet vom Prinzip der Collage verhandelt werden. Dieses Textprinzip wird zum Handlungsprinzip des Workshops: Die Teilnehmenden werden dem Versuch ausgesetzt, in kleinen Gruppen auf dem digitalen Whiteboard sowohl mit dem bereitgestellten als auch mit eigenem Material selbst Collagen zu erstellen. In dem experimentellen Format des Workshops konturiert sich performativ ein ästhetisch-digitaler Möglichkeits- und Erfahrungsraum, in dem die individuellen Positionen und Perspektiven aller Beteiligten über Text, Bild und Sprache interaktiv in vernetzende Artikulationsformen treten. In den entstandenen Collagen kommen Aspekte von Ästhetik, Digitalität und Macht in eindrücklicher Weise zum Tragen.This contribution documents – especially visually – impressions, observations and results from an online workshop «Interaction and Participation in Cultural Education», which aimed to present topics, working methods and principles of the research cluster. It made sense to conceptualize the workshop itself in an interactive and participative manner, as well as along the theme of the framing conference. A large part of the communication is shifted to a digital whiteboard parallel to the video conference, on which all participants can act individually and together. Central fragments from a text of the cluster are available as material, in which the terms interaction and participation are negotiated in a joint self-experiment and guided by the principle of collage. The text principle becomes the operating principle of the workshop: The participants are exposed to the attempt to create collages themselves in small groups on the digital whiteboard using both the provided and their own material. In the experimental format of the workshop, an aesthetic-digital space of possibility and experience is contoured performatively, in which the individual positions and perspectives of all participants interactively enter into networked forms of articulation via text, image and language. In the resulting collages, aspects of aesthetics, digitality and power come into play in an impressive way

Astro2020 APC White Paper: Theoretical Astrophysics 2020-2030

The past two decades have seen a tremendous investment in observational facilities that promise to reveal new and unprecedented discoveries about the universe. In comparison, the investment in theoretical work is completely dwarfed, even though theory plays a crucial role in the interpretation of these observations, predicting new types of phenomena, and informing observing strategies. In this white paper, we argue that in order to reach the promised critical breakthroughs in astrophysics over the next decade and well beyond, the national agencies must take a serious approach to investment in theoretical astrophysics research. We discuss the role of theory in shaping our understanding of the universe, and then we provide a multi-level strategy, from the grassroots to the national, to address the current underinvestment in theory relative to observational work

The Local Group on FIRE: Dwarf galaxy populations across a suite of hydrodynamic simulations

We present a new set of high-resolution hydrodynamic cosmological zoom-in simulations that apply the Feedback In Realistic Environments physics to both Local Group (LG)-like and isolated Milky Way (MW)-like volumes (10 host systems in total with a baryonic particle mass ≃3500−7000M⁠). We study the stellar mass functions, circular velocity or mass profiles, and velocity dispersions of the dwarf galaxy populations. The simulations reproduce the stellar mass function and central densities of MW satellite dwarfs for M∗≥10^(5.5) M⊙ and predict the existence of ∼3 unidentified galaxies with M∗∼10^5M⊙ within 300 kpc of the MW. Overall, we find no evidence for the classical missing satellites or too-big-to-fail (TBTF) problems for satellite galaxies in our sample. Among the satellites, TBTF is resolved primarily by subhalo disruption and overall mass-loss; central density profiles of subhaloes are of secondary importance. For non-satellite galaxies, our LG-like simulations predict as many as ∼10 as-of-yet unseen galaxies at distances 0.3−1Mpc from both hosts, with M∗≃10^(5−6) M⊙ (in haloes with V_(max) ∼ 20 km s^(−1)), albeit with large halo-to-halo variance. None of our simulations produces a compact, baryon-dominated, high-density dwarf elliptical-type galaxy (with V_(circ) ≳ 35 km s^(−1) at r < 1kpc), of which six may appear in the LG (but none in the MW). It may therefore remain a challenge to reproduce the full diversity of the dwarf population, including both the highest and lowest density systems