297 research outputs found
Untersuchung zur unterrichtlichen Nutzung eines Naturkundemuseums
No full textWilde M, Klautke S. Untersuchung zur unterrichtlichen Nutzung eines Naturkundemuseums. In: Vogt H, Retzlaff-Fuerst C, eds. Erkenntnisweg Biologiedidaktik. Vol 1. Rostock: Universitätsdruckerei; 2002: 101-111
Identifying Agnotological Ploys: How to Stay Clear of Unjustified Dissent
No full textCarrier M. Identifying Agnotological Ploys: How to Stay Clear of Unjustified Dissent. In: Christian A, Hommen D, Retzlaff N, Schurz G, eds. Philosophy of Science. Between the Natural Science, the Social Sciences, and the Humanities. European Studies in Philosophy of Science. Vol 9. Cham: Springer; 2018: 155-169
The Great Observatories Origins Deep Survey VLT/ISAAC near-infrared imaging of the GOODS-South field
No full textAims. We present the final public data release of the VLT/ISAAC near-infrared imaging survey in the GOODS-South field. The survey covers an area of 172.5, 159.6 and 173.1 arcmin(2) in the J, H, and K(s) bands, respectively. For point sources total limiting magnitudes of J = 25.0, H = 24.5, and K(s) = 24.4 (5 sigma, AB) are reached within 75% of the survey area. Thus these observations are significantly deeper than the previous EIS Deep Public Survey which covers the same region. The image quality is characterized by a point spread function ranging between 0.34 '' and 0.65 '' FWHM. The images are registered to a common astrometric grid defined by the GSC 2 with an accuracy of similar to 0.06 '' RMS over the whole field. The overall photometric accuracy, including all systematic effects, adds up to 0.05 mag. The data are publicly available from the ESO science archive facility. Methods. We describe the data reduction, the calibration, and the quality control process. The final data set is characterized in terms of astrometric and photometric properties, including the PSF and the curve of growth. We establish an empirical model for the sky background noise in order to quantify the variation of limiting depth and statistical photometric errors over the survey area. We define a catalog of K(s)-selected sources which contains JHK(s) photometry for 7079 objects. Differential aperture corrections were applied to the color measurements in order to avoid possible biases as a result of the variation of the PSF. We briefly discuss the resulting color distributions in the context of available redshift data. Furthermore, we estimate the completeness fraction and relative contamination due to spurious detections for source catalogs extracted from the survey data. For this purpose, an empirical study based on a deep Ks image of the Hubble Ultra Deep Field is combined with extensive image simulations. Results. With respect to previous deep near-infrared surveys, the surface density of faint galaxies has been established with unprecedented accuracy by virtue of the unique combination of depth and area of this survey. We derived galaxy number counts over eight magnitudes in flux up to J = 25.25, H = 25.0, K(s) = 25.25 (in the AB system). Very similar faint-end logarithmic slopes between 0.24 and 0.27 mag(-1) were measured in the three bands. We found no evidence for a significant change in the slope of the logarithmic galaxy number counts at the faint end
Non-formales Biologielernen mit Schulbezug
No full textWilde M, Retzlaff-Fürst C, Scheersoi A, Basten M, Groß J. Non-formales Biologielernen mit Schulbezug. In: Groß J, Hammann M, Schmiemann P, Zabel J, eds. Biologiedidaktische Forschung: Erträge für die Praxis. Heidelberg: Springer; 2019: 251-268
Percolation in real wildfires
No full textThis paper focuses on the statistical properties of wild-land fires and, in particular, investigates if spread dynamics relates to simple invasion model. The fractal dimension and lacunarity of three fire scars classified from satellite imagery are analysed. Results indicate that the burned clusters behave similarly to percolation clusters on boundaries and look denser in their core. We show that Dynamical Percolation reproduces this behaviour and can help to describe the fire evolution. By mapping fire dynamics onto the percolation models, the strategies for fire control might be improved
Antibacterial effectiveness of a second generation steam pasteurization™ system for beef carcass decontamination
No full textThe original commercial Steam Pasteurization
™ System (SPS 400) involved a sealable
moving car by which carcass sides were carried
through the steam chamber at standard line
speeds. A second generation “static chamber”
system (SPS 400-SC) eliminates the mechanical
moving car and has been installed in a large beef
slaughter facility. We collected data to verify
SPS 400-SC’s effectiveness at chamber temperatures
from 185 to 205EF in a batch process
mode (only test carcasses passing through the
unit at variable intervals to facilitate collection of
research samples) and at 190EF with the system
running continuously. Tissue samples were
obtained from different carcass anatomical
locations to evaluate the uniformity of thermal
treatment. Batch-type steam treatment at 185
and 190EF did not consistently produce significant
bacterial reductions on the five anatomical
locations sampled. Batch processing at 195,
200, and 205EF provided increasingly greater
total bacterial reductions, ranging from 1.0 to
2.0 log colony forming units (CFU)/cm2. Under
continuous operation at 190EF, typical of commercial
operation, total bacterial reductions at
the carcass midline averaged 1.6 log CFU/cm2.
The new SPS design is substantially simplified in
terms of moving components and should offer
highly efficient operation and less mechanical
upkeep, extremely important in Hazard Analysis
Critical Control Point (HACCP) programs,
which require assurance of virtually 100%
system operation. The new SPS 400-SC
design will provide beef processors a very
effective and reliable means of assuring that
microbiologically clean carcasses enter the
holding cooler, thus substantially reducing the
risk of pathogenic contamination
Reply to the Comment by H. Tephany and J. Nahmias on "Percolation in real wildfires" by G. Caldarelli et al.
No full textIn a previous paper we analyzed the satellite images of three big wildfires in the Mediterranean area. The main result of this analysis is that the burnt area is quite compact, with a fractalperimeter (at least up to a characteristic scale), with a fractal dimension D = 4/3.In their comment to our paper, Tephany et al. propose another mechanism for the stopping of the progress of the wildfire and the formation of such a perimeter. Following their argument the spread is stopped by a pinning mechanism due to the “reaching of a critical local value of reactants average concentration” for many possible reasons (fuel variations, metereological conditions, topography, and human intervention).We agree completely with Tephany et al. that these are the real causes of the stopping. However, once these causes are identified, one needs a universal mechanism of formation of afractal perimeter with D = 4/3.We then want to stress the fact that our model takes into account the above mechanism in an effective way justified by the universality of the percolation properties
Tree-based sap flow monitoring to validate the crop water stress index in hazelnut
No full textLarge-scale hazelnut orchards need a fast and cost-effective method to estimate plant water status to properly manage irrigation. Imagery captured by unmanned aerial vehicles (UAV) is a promising technique because canopy temperature can be related to plant transpiration. This work aims to identify a correlation between the crop water stress index (CWSI) derived from UAV thermal images and the transpiration of hazelnut in the frame of the Pantheon project. The study was set in a private hazelnut orchard located in Viterbo Province (central Italy). The orchard of Tonda Romana was planted in 2010 in a 5×5 m planting design. Plants were grown as a free vase with 9 branches per plant and a mean branch diameter of 6.9 cm. The trial included a rain fed (control) and a sub-irrigated treatment. We installed thermal dissipation probes on 4 branches per treatment. A datalogger collected the sap flow data every 15 min during 2020 together with meteorological parameters. Sap flow, tree biometrics and microclimatic parameters served to estimate stem conductance. The UAV equipped with a thermal camera flew at an altitude of about 25 m which resulted in a ground resolution of around 2.7 cm pixel‐1. The CWSI was extrapolated for the sap flow-monitored plants for 5 sample days and related to the plant conductance. Results showed that Tonda Romana has a good water saving strategy through tight stomatal closure when it is well irrigated or sufficiently rain fed. The CWSI has a promising correlation with plant conductance. In 2020 there was no lack of rain, thus sap flow sensors showed no significant differences in the irrigation trials; this agrees with CWSI results. Still UAV-based water status assessment might be more helpful in areas with lower precipitation, while sap flow sensors are more likely to catch small differences in water status
Synthese von Bildern mittels parametrisierter Modelle für die automatische optische Inspektion (AOI)
No full textS.251-261Bei Entwurf und Optimierung von Systemen zur automatischen optischen Inspektion ist eine systematische Evaluierung von großer Bedeutung, um hohe Qualität zu erreichen und zu garantieren, zugleich aber *Corresponding author: Max-Gerd Retzlaff, Karlsruhe Institute of Technology (KIT), Institute for Visualization and Data Analysis, Computer Graphics Group, Karlsruhe; and Fraunhofer Institute of Optronics, System Technologies and Image Exploitation (IOSB), Karlsruhe, e-mail: [email protected] Josua Stabenow, Carsten Dachsbacher: Karlsruhe Institute of Technology (KIT), Institute for Visualization and Data Analysis, Computer Graphics Group, Karlsruhe Jürgen Beyerer: Karlsruhe Institute of Technology (KIT), Institute for Anthropomatics and Robotics, Vision and Fusion Laboratory (IES), Karlsruhe; and Fraunhofer Institute of Optronics, System Technologies and Image Exploitation (IOSB), Karlsruhe kostspielig. Methoden der Computergrafik können eingesetzt werden, um schnell große virtuelle Kontrollproben von Testobjekten zu erzeugen und die Bildgewinnung zu simulieren. Wir verwenden Techniken der prozeduralen Modellierung, um virtuelle Objekte in großer Vielfalt und mit variantenreichem Aussehen zu erzeugen, die reale Objekte und Messproben nachahmen. Physikalische Simulation von Starrkörpern wird verwendet, um die Platzierung der virtuellen Objekte zu simulieren, und mit physikalisch basierten Rendering-Methoden erzeugen wir synthetische Bilder. Diese Bilder werden als Eingabe für ein AOI-System anstatt physikalisch gewonnener Bilder eingesetzt. Dieses Vorgehen erlaubt eine Entwicklung, Verbesserung und Evaluierung der Bildverarbeitungs- und Klassifikationsschritte eines AOI-Systems unabhängig von einer physischen Realisierung. Wir demonstrieren den vorgestellten Ansatz für Glasscherben, da die Glassortierung eine anspruchsvolle praktische Anwendung der AOI darstellt.When designing or improving systems for automated optical inspection (AOI), systematic evaluation is an important but costly necessity to achieve and ensure high quality. Computer graphics methods can be used to quickly create large virtual sets of samples of test objects and to simulate image acquisition setups. We use procedural modeling techniques to generate virtual objects with varying appearance and properties, mimicking real objects and sample sets. Physical simulation of rigid bodies is deployed to simulate the placement of virtual objects, and using physically-based rendering techniques we create synthetic images. These are used as input to an AOI system instead of physically acquired images. This enables the development, optimization, and evaluation of the image processing and classification steps of an AOI system independently of a physical realization. We demonstrate this approach for shards of glass, as sorting glass is one challenging practical application for AOI.82Nr.
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