Hybrid One-Shot 3D Hand Pose Estimation by Exploiting Uncertainties

Model-based approaches to 3D hand tracking have been shown to perform well in a wide range of scenarios. However, they require initialisation and cannot recover easily from tracking failures that occur due to fast hand motions. Data-driven approaches, on the other hand, can quickly deliver a solution, but the results often suffer from lower accuracy or missing anatomical validity compared to those obtained from model-based approaches. In this work we propose a hybrid approach for hand pose estimation from a single depth image. First, a learned regressor is employed to deliver multiple initial hypotheses for the 3D position of each hand joint. Subsequently, the kinematic parameters of a 3D hand model are found by deliberately exploiting the inherent uncertainty of the inferred joint proposals. This way, the method provides anatomically valid and accurate solutions without requiring manual initialisation or suffering from track losses. Quantitative results on several standard datasets demonstrate that the proposed method outperforms state-of-the-art representatives of the model-based, data-driven and hybrid paradigms.Comment: BMVC 2015 (oral); see also http://lrs.icg.tugraz.at/research/hybridhape

PetroSurf3D - A Dataset for high-resolution 3D Surface Segmentation

The development of powerful 3D scanning hardware and reconstruction algorithms has strongly promoted the generation of 3D surface reconstructions in different domains. An area of special interest for such 3D reconstructions is the cultural heritage domain, where surface reconstructions are generated to digitally preserve historical artifacts. While reconstruction quality nowadays is sufficient in many cases, the robust analysis (e.g. segmentation, matching, and classification) of reconstructed 3D data is still an open topic. In this paper, we target the automatic and interactive segmentation of high-resolution 3D surface reconstructions from the archaeological domain. To foster research in this field, we introduce a fully annotated and publicly available large-scale 3D surface dataset including high-resolution meshes, depth maps and point clouds as a novel benchmark dataset to the community. We provide baseline results for our existing random forest-based approach and for the first time investigate segmentation with convolutional neural networks (CNNs) on the data. Results show that both approaches have complementary strengths and weaknesses and that the provided dataset represents a challenge for future research.Comment: CBMI Submission; Dataset and more information can be found at http://lrs.icg.tugraz.at/research/petroglyphsegmentation

Exploring the Reactivity of a Frustrated Sn/P Lewis Pair: the Highly Selective Complexation of the cis-Azobenzene Photoisomer

Holtkamp P, Poier D, Neumann B, Stammler H-G, Mitzel NW. Exploring the Reactivity of a Frustrated Sn/P Lewis Pair: the Highly Selective Complexation of the cis-Azobenzene Photoisomer. Chemistry - A European Journal. 2021;27(11):3793-3798.The reactivity of the geminal frustrated Lewis pair (FLP) (F 5 C 2 ) 3 Sn-CH 2 -P(tBu) 2 ( 1 ) was explored by reacting it with a variety of small molecules (PhOCN, PhNCS, PhCCH, tBuCCH, H 3 CC(O)-CH=CH 2 , Ph[C(O)] 2 Ph, PhN=NPh and Me 3 SiCHN 2 ), featuring polar or non-polar multiple bonds and/or represent alpha,beta-unsaturated systems. While most adducts are formed readily, the binding of azobenzene requires UV-induced photoisomerization, which results in the highly selective complexation of cis-azobenzene. In case of benzil, the reac-tion does not lead to the expected 1,2- or 1,4-addition products, but to the non-stereoselective (tBu) 2 PCH 2 -transfer to a prochiral keto func-tion of benzil. All adducts of 1 were characterised by means of multi-nuclear NMR spectroscopy, elemental analyses and X-ray diffraction experiments. © 2020 Wiley-VCH GmbH

Shift of dietary carbohydrate source from milk to various solid feeds reshapes the rumen and fecal microbiome in calves

Abstract The transition from milk to solid diets drastically impacts the gut microbiome of calves. We explored the microbial communities of ruminal fluid and feces of Holstein calves when fed milk on d 7 of life, and when fed solid feeds based on either medium- or high-quality hay with or without concentrate inclusion (70% in fresh matter) on d 91. Ruminal fluid and feces had distinct microbial compositions already on d 7, showing that niche specialization in early-life gut is rather diet-independent. Changes between d 7 and d 91 were accompanied by a general increase in microbial diversity. Solid diets differed largely in their carbohydrate composition, being reflected in major changes on d 91, whereby concentrate inclusion was the main driver for differences among groups and strongly decreased microbial diversity in both matrices. Fecal enterotyping revealed two clusters: concentrate-supplemented animals had an enterotype prevalent in Prevotella, Succinivibrio and Anaerovibrio, whereas the enterotype of animals without concentrate was dominated by fibrolytic Ruminococcaceae. Hay quality also affected microbial composition and, compared to medium-quality, high-quality hay reduced alpha-diversity metrics. Concluding, our study revealed that concentrate inclusion, more than hay quality, dictates the establishment of niche-specific, microbial communities in the rumen and feces of calves

Ein Schwefelmonoxid‐Addukt eines frustrierten Sn/P‐Lewis‐Paares

Holtkamp P, Glodde T, Poier D, Neumann B, Stammler H-G, Mitzel NW. Ein Schwefelmonoxid‐Addukt eines frustrierten Sn/P‐Lewis‐Paares. Angewandte Chemie. 2020;132(40):17541-17545.Die Reaktion des geminalen frustrierten Lewis-Paares (F5C2)3SnCH2P(tBu)2(1) mit N-Sulfinylanilin PhNSOergab das erste Schwefelmonoxid-Addukt eines Hauptgrup-penmetalls (F5C2)3SnCH2P(tBu)2·SO (2). Es enthält einenSnCPSO-Ring. Das zweite Produkt ist ein Phenylnitren-Addukt von1. Die überraschende Stabilität von2wurde mitdenen der bisher unzugänglichen O2- und S2-Addukte von1verglichen. Versuche, diese aus1und den elementarenChalkogenen (O2,S8,Se1,Te1) herzustellen, führten zu vier-gliedrigen SnCPE-Ringsystemen. Quantenchemische Unter-suchungen von2zeigen den Beitrag der Bindungspolarität derSO-Einheit zur Stabilisierung von2