ARGon3: "3D appearance robot-based gonioreflectometer" at PTB

At the Physikalisch-Technische Bundesanstalt, the National Metrology Institute of Germany, a new facility for measuring visual appearance-related quantities has been built up. The acronym ARGon(3) stands for "3D appearance robot-based gonioreflectometer". Compared to standard gonioreflectometers, there are two main new features within this setup. First, a photometric luminance camera with a spatial resolution of 28 μm on the device under test (DUT) enables spatially high-resolved measurements of luminance and color coordinates. Second, a line-scan CCD-camera mounted to a spectrometer provides measurements of the radiance factor, respectively the bidirectional reflectance distribution function, in full V(λ)-range (360 nm-830 nm) with arbitrary angles of irradiation and detection relative to the surface normal, on a time scale of about 2 min. First goniometric measurements of diffuse reflection within 3D-space above the DUT with subsequent colorimetric representation of the obtained data of special effect pigments based on the interference effect are presented.     

Comparative housing,urban crisis and political economy: an ethnographically based ‘long view’ from Auckland,Singapore and Berlin

Abstract

This paper follows a call for a ‘long view’ perspective on contemporary housing problems and policy. It applies this longitudinal lens to a multi-city comparative ethnographical study that investigates and relates place-specific and common trajectories and policies in regard to contemporary urban housing. By comparing Auckland, Singapore and Berlin from a heterodox political economy perspective, it demonstrates how contemporary challenges and proposed solutions over housing have deep-seated historical and geographical roots that are usually overlooked. It suggests that comprehending current housing issues as cumulative effects of developments and policy (non)-action taken in the past, and relating and evaluating those constitutive trajectories and transformations across (disparate) cities, current academic and policy debates can be enriched and deepened. One lesson is that ‘learning from the past’ may be a more promising crisis response than nowadays’ politically fetishised learning via global best practice and spatially mobilised policy.     

Freezing point and other technological properties of milk of the Polish Coldblood horse breed

Mare milk is a valued and sought-after raw material for the production of innovative dairy products. The high demand, low supply, high price, and lack of accurate characterization of the milk of a given horse breed may provoke its deliberate fraudulent dilution. The aim of this work was to analyze the freezing point against a background of various selected technological parameters of Polish Coldblood mare milk. Research was carried out on multiparous Polish Coldblood mares from 5 to 8 yr of age with live weights between 618 and 851 kg. Their milk was tested on d 1, 3, and 7 postpartum and once a month for the next 9 mo of lactation (n = 52). Milk from 13 mares, taken daily in mo 4 of lactation, was collected for the dilution study (n = 403). The basic composition of the milk was as follows: solids-not-fat, 84.4 g/kg, fat 15.1 g/kg, lactose 65.3 g/kg, and total protein 24.2 g/kg (made up of casein, 14.6 g/kg, and whey protein, 9.5 g/kg). The dominant amino acids were glutamic acid, proline, leucine, and aspartic acid. The mean freezing point during a 9-mo lactation was ?0.557°C (coefficient of variation = ?2.787; 5th to 95th percentile: ?0.563 to ?0.550°C). Based on our analysis, we adopted ?0.550°C (from 3 to 6 mo) as the reference value for milk from the Polish Coldblood horse. Analysis of the model of changes in freezing point, after dilution, using the coefficient of determination and Akaike's information criterion, showed that a linear model could be recommended (y = 79.35 + 144.35x). Addition of 1% water increased the freezing point of Polish Coldblood mare milk by 0.0069°C.     

Passively operated vapor-fed direct methanol fuel cells for portable applications

The impact of structural parameters and operating conditions has not been researched yet for vapor-fed operation of a DMFC at near-ambient conditions. Thus, a detailed parameter study that included reference cell measurements to assess anode and cathode losses separately was performed. Among other parameters like temperature or air stoichiometry, different opening ratios that controlled evaporation of methanol into the vapor chamber were examined.     

BichiCAM,an Underwater Automated Video Tracking System for the Study of Migratory Dynamics of Benthic Diadromous Species in Streams

Conventional methods for surveying diadromous fish migration from marine coastal waters to freshwater habitats are mainly based on electrofishing, a non‐optimal technique for the study of fish migrations in rivers, and fishermen catch data. Underwater video has been recognized for a long time as a good alternative, but those approaches usually require intensive labour for retrieving the information from the video sequences. To overcome these problems, an underwater video system specifically designed for field work (low‐weight, low‐cost and autonomous) named BichiCAM has been developed for automatically counting, measuring and tracking fish observed in video sequences. The efficiency and precision of the BichiCAM system were tested by filming Sicyopterus lagocephalus juveniles passing through the camera field of vision in the Saint‐Etienne River, Reunion Island, Western Indian Ocean. The BichiCAM system accurately measured fish length of the observed individuals when lens distortion of the camera was corrected, and the error percentages on the measurements presented a standard deviation of 5.1% of the total length. The BichiCAM system provides a powerful tool that will not only facilitate research on migrating fishes and invertebrates' communities but also allow studies of the effectiveness of fishways associated to dams or the impacts of fishery activities. Copyright © 2015 John Wiley & Sons, Ltd.     

Computations of fatigue crack growth with strain gradient plasticity and an irreversible cohesive zone model

Computations of fatigue crack growth with a first-order strain gradient plasticity (SGP) model and an irreversible cohesive zone model are reported. SGP plays a significant role in the model predictions and leads to increased fatigue crack growth rates relative to predictions with classical plasticity. Increased magnitudes of tractions and material separation at the crack tip together with reduced crack closure appear as the cause for accelerated crack growth in SGP. Under plane strain conditions SGP appears as an essential feature of the development of the crack closure zone. Size effects are explored relative to changes in internal material length scale as well as to structural length scales.     

Music playlist generation by adapted simulated annealing

We present the design of an algorithm for use in an interactive music system that automatically generates music playlists that fit the music preferences of a user. To this end, we introduce a formal model, define the problem of automatic playlist generation (APG), and prove its NP-hardness. We use a local search (LS) procedure employing a heuristic improvement to standard simulated annealing (SA) to solve the APG problem. In order to employ this LS procedure, we introduce an optimization variant of the APG problem, which includes the definition of penalty functions and a neighborhood structure. To improve upon the performance of the standard SA algorithm, we incorporated three heuristics referred to as song domain reduction, partial constraint voting, and a two-level neighborhood structure. We evaluate the developed algorithm by comparing it to a previously developed approach based on constraint satisfaction (CS), both in terms of run time performance and quality of the solutions. For the latter we not only considered the penalty of the resulting solutions, but we also performed a conclusive user evaluation to assess the subjective quality of the playlists generated by both algorithms. In all tests, the LS algorithm was shown to be a dramatic improvement over the CS algorithm.