Automatic classification of building types in 3D city models

This article presents a classifier based on Support Vector Machines (SVMs), an advanced machine learning method for semantic enrichment of coarse 3D city models by deriving the building type. The information on the building type (detached building, terraced building, etc.) is essential for a variety of relevant applications of 3D city models like spatial marketing, real estate management and marketing, and for visualization. The derivation of the building type from coarse data (mainly 2D footprints, building heights and functions) seems impossible at first sight. However it succeeds by incorporating the spatial context of a building. Since the input data can be derived easily and at very low cost, this method is widely applicable. Nevertheless, as with all supervised learning algorithms, obtaining labelled training data is very time-consuming. Herewith, we provide a method which uses outlier detection and clustering methods to support users in efficiently and rapidly obtaining adequate training data.     

Inseparability and Strong Hypotheses for Disjoint NP Pairs

This paper investigates the existence of inseparable disjoint pairs of NP languages and related strong hypotheses in computational complexity. Our main theorem says that, if NP does not have measure 0 in EXP, then there exist disjoint pairs of NP languages that are P-inseparable, in fact ${\mathrm {TIME}(2^{n^{k}})}$ -inseparable. We also relate these conditions to strong hypotheses concerning randomness and genericity of disjoint pairs.     

Performance of an adaptive liquid microlens controlled by a microcoil actuator

We present an optofluidic system based on electromagnetic manipulation of a ferrofluid to tune a liquid lens. Both studies of the dynamics of fluid transport and of the optical properties of the liquid lens have been carried out. Thermal and magnetic field simulations of the microcoil actuators are presented. Proof-of-principle experiments demonstrating the adaption of the focal length of the lens have been carried out. It is shown that the lens adaption proceeds in a reversible and reproducible manner, given that the ferrofluid plug moves with a speed below a specific threshold value. Furthermore, the time delay between the actuation and the deflection of the lens surface is studied.     

Electro‐Oxidation of Ni42 Steel: A Highly Active Bifunctional Electrocatalyst

Janus type water‐splitting catalysts have attracted highest attention as a tool of choice for solar to fuel conversion. AISI Ni42 steel is upon harsh anodization converted into a bifunctional electrocatalyst. Oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) are highly efficiently and steadfast catalyzed at pH 7, 13, 14, 14.6 (OER) and at pH 0, 1, 13, 14, 14.6 (HER), respectively. The current density taken from long‐term OER measurements in pH 7 buffer solution upon the electro‐activated steel at 491 mV overpotential (η) is around four times higher (4 mA cm^?2) in comparison with recently developed OER electrocatalysts. The very strong voltage–current behavior of the catalyst shown in OER polarization experiments at both pH 7 and at pH 13 are even superior to those known for IrO₂‐RuO₂. No degradation of the catalyst is detected even when conditions close to standard industrial operations are applied to the catalyst. A stable Ni‐, Fe‐oxide based passivating layer sufficiently protects the bare metal for further oxidation. Quantitative charge to oxygen (OER) and charge to hydrogen (HER) conversion are confirmed. High‐resolution XPS spectra show that most likely γ?NiO(OH) and FeO(OH) are the catalytic active OER and NiO is the catalytic active HER species.     

How should the societal impact of research be generated and measured? A proposal for a simple and practicable approach to allow interdisciplinary comparisons

Since the 1990s, the scope of research evaluation has widened to encompass the societal products (outputs), societal use (societal references) and societal benefits (changes in society) of research. Research evaluation has been extended to include measures of the (1) social, (2) cultural, (3) environmental and (4) economic returns from publicly funded research. Even though no robust or reliable methods for measuring societal impact have yet been developed. In this study, we would like to introduce an approach which, unlike the currently common case study approach (and others), is relatively simple, can be used in almost every subject area and delivers results regarding societal impact which can be compared between disciplines. Our approach to societal impact starts with the actual function of science in society: to generate reliable knowledge. That is why a study (which we would like to refer to as an assessment report) summarising the status of the research on a certain subject represents knowledge which is available for society to access. Societal impact is given when the content of a report is addressed outside of science (in a government document, for example).     

The impact of metal doping on fumed silica structure and amino acid thermal condensation catalytic properties

Fumed silica nanoparticles (FSN) are one of the most common synthetic forms of silica, but prolonged exposure leads to cell toxicity and apoptosis due to reactive oxygen species (ROS) generation and cell membrane perturbation resulting from hydrogen bonding and electrostatic interactions. Increasing attention is being put on synthesizing FSN material that is safer both for workers involved in large-scale industrial production, and consumers coming in contact with FSN additives. In the present work, we explore the molecular structural differences and efficacy of Al- and Ti-metal-doped FSN which has previously been shown to reduce toxicity effects of FSN. We use a combination of ²⁹Si and ²⁷Al solid-state magic angle spinning (MAS) NMR, Raman spectroscopy, and thermogravimetric analysis (TGA) to probe the surface and bulk structure and quantify the adsorption capacity and reactivity of the metal-doped FSN with respect to amino acid thermal condensation. Alanine was selected as the amino acid of choice for its simplicity and ubiquity in biochemical reactions. The results indicate that metal doping has a modest impact on the fumed silica molecular structure with a small decrease in amino acid adsorption capacity and thermal condensation reactivity as a function of increased metal doping.

Graphical Abstract

     

A unified theory for optimal feedforward torque control of anisotropic synchronous machines

A unified theory for optimal feedforward torque control of anisotropic synchronous machines with non-negligible stator resistance and mutual inductance is presented which allows to analytically compute (1) the optimal direct and quadrature reference currents for all operating strategies, such as maximum torque per current (MTPC), maximum current, field weakening, maximum torque per voltage (MTPV) or maximum torque per flux (MTPF), and (2) the transition points indicating when to switch between the operating strategies due to speed, voltage or current constraints. The analytical solutions allow for an (almost) instantaneous selection and computation of actual operation strategy and corresponding reference currents. Numerical methods (approximating these solutions only) are no longer required. The unified theory is based on one simple idea: all optimisation problems, their respective constraints and the computation of the intersection point(s) of voltage ellipse, current circle or torque, MTPC, MTPV, MTPF hyperbolas are reformulated implicitly as quadrics which allows to invoke the Lagrangian formalism and to find the roots of fourth-order polynomials analytically. The proposed theory is suitable for any anisotropic synchronous machine. Implementation and measurement results illustrate effectiveness and applicability of the theoretical findings in real world.     

Indentation modulus extrapolation and thickness estimation of ta-C coatings from nanoindentation

Coatings used in tribological applications often exhibit high hardness and stiffness to achieve high wear resistance. One coating characterization method frequently used is nanoindentation which allows the determination of indentation hardness and indentation modulus among other material properties. The indentation modulus describes the elastic surface behavior during indentation and is, among hardness, a direct indicator for wear resistance. To obtain the true indentation modulus of a coating, it must be measured with varying loads and then extrapolated to zero load. Current recommendation of the standard ISO 14577-4:2016 is a linear extrapolation which fits poorly for nonlinear curves. Such nonlinear curves are commonly found for high hardness mismatches between coating and substrate, for example, superhard tetrahedral amorphous carbon coatings (ta-C) on a steel substrate. In this study, we present a new empirical fit model, henceforth named sigmoid. This fit model is compared to several existing fit models described in the literature using a large number of nanoindentation measurements on ta-C coatings with wide ranges of indentation modulus and coating thickness. This is done by employing a user-independent and model agnostic fitting methodology. It is shown that the sigmoid model outperforms all other models in the combination of goodness of fit and stability of fit. Furthermore, we demonstrate that the sigmoid model’s fit parameter directly correlates with coating thickness and thus allows for a new approach of determining ta-C coating thickness from nanoindentation.

     

Effect of feeding colostrum at different volumes and subsequent number of transition milk feeds on the serum immunoglobulin G concentration and health status of dairy calves

Transfer of sufficient IgG to the newborn calf via colostrum is vital to provide it with adequate immunological protection and resistance to disease. The objectives of the present study were to compare serum IgG concentration and health parameters of calves (1) fed different volumes of colostrum [7, 8.5, or 10% of body weight (BW)] within 2 h of birth and (2) given 0, 2, or 4 subsequent feedings of transition milk (i.e., milkings 2 to 6 postcalving). Ninety-nine dairy calves were fed 7, 8.5, or 10% of BW in colostrum within 2 h of birth and given 0, 2, or 4 subsequent feedings of transition milk. The concentration of IgG in the serum of calves was measured at 24, 48, 72, and 642 h of age by an ELISA. The apparent efficiency of absorption for IgG was determined. Health scores were assigned to calves twice per week and all episodes of disease were recorded. The effect of experimental treatment on calf serum IgG concentration differed by the age of the calf. Calves fed 8.5% of BW in colostrum had a greater mean serum IgG concentration than calves fed 7 or 10% of BW at 24, 48, and 72 h of age. At 642 h of age, serum IgG concentrations of calves fed 8.5% of BW (24.2 g/L) and calves fed 10% of BW (21.6 g/L) did not differ, although the serum IgG concentration of calves fed 8.5% of BW was still greater than that of calves fed 7% of BW (20.7 g/L). No difference in serum IgG concentration existed between calves fed 7% of BW and those fed 10% of BW at any age. No significant effect of number of subsequent feedings of transition milk on calf serum IgG concentration was detected. The apparent efficiency of absorption of calves fed 8.5% of BW in colostrum (38%) was greater than calves fed 7% of BW in colostrum (26%) and tended to be greater than in calves fed 10% of BW (29%). Calves fed further feedings of transition milk after the initial feeding of colostrum had a lower odds (0.62; 95% confidence interval: 0.41 to 0.93) of being assigned a worse eye/ear score (i.e., a more copious ocular discharge or pronounced ear droop) and a lower odds (0.5; 95% confidence interval: 0.32 to 0.79) of being assigned a worse nasal score (i.e., a more copious and purulent nasal discharge) during the study period relative to calves that received no further feedings of transition milk. In conclusion, calves fed 8.5% of BW in colostrum within 2 h of birth achieved a greater concentration of IgG in serum in the first 3 d of life than calves fed either 7 or 10% of BW. Feeding calves transition milk subsequently reduced their odds of being assigned a worse eye/ear and nasal score.