237 research outputs found
Effect of V and N on the microstructure evolution during continuous casting of steel
Low Carbon (LC) steel is not expected to be sensitive to hot tearing and/or cracking while microalloyed steels are known for their high cracking sensitivity during continuous casting. Experience of the Direct Sheet Plant caster at Tata Steel in Ijmuiden (the Netherlands), seems to contradict this statement. It is observed that a LC steel grade has a high risk of cracking alias hot tearing, while a High Strength Low Alloyed (HSLA) steel has a very low cracking occurrence. Another HSLA steel grade, with a similar composition but less N and V is however very sensitive to hot tearing. An extreme crack results in a breakout. A previous statistical analysis of the breakout occurrence reveals a one and a half times higher possibility of a breakout for the HSLA grade compared to the LC grade. HSLA with extra N, V shows a four times smaller possibility of breakout than LC. This study assigns the unexpected effect of the chemical composition on the hot tearing sensitivity to the role of some alloying elements such as V and N as structure refiners.This research was carried out under project number M41.5.08320 within the framework of the
Research Program of the Materials innovation institute M2i (www.m2i.nl)
OpenML Benchmarking Suites
Machine learning research depends on objectively interpretable, comparable,
and reproducible algorithm benchmarks. Therefore, we advocate the use of
curated, comprehensive suites of machine learning tasks to standardize the
setup, execution, and reporting of benchmarks. We enable this through software
tools that help to create and leverage these benchmarking suites. These are
seamlessly integrated into the OpenML platform, and accessible through
interfaces in Python, Java, and R. OpenML benchmarking suites are (a) easy to
use through standardized data formats, APIs, and client libraries; (b)
machine-readable, with extensive meta-information on the included datasets; and
(c) allow benchmarks to be shared and reused in future studies. We also present
a first, carefully curated and practical benchmarking suite for classification:
the OpenML Curated Classification benchmarking suite 2018 (OpenML-CC18)
Pig fecal and tonsil contamination of Yersinia enterocolita in one French slaughterhouse
Pig is considered to be the main animal reservoir of human pathogenic Yersinia enterocolitica strains which is frequently isolated from tonsils, but can also be found in the feces and onto carcasses. In France, while the main pathogenic biotypes are known for humans, few data are available regarding their prevalence in the pork chain production, and generally focus on tonsils contamination
Applying configurational theory to build a typology of ethnocentric consumers
Purpose – Individuals showing high consumer ethnocentrism (CE) prefer domestic over foreign-made products and their preferences may contribute to barriers to international market entry. Therefore, how to identify such consumers is an important question. Shankarmahesh’s (2006) review reveals inconsistencies in the literature with regard to CE and its antecedents. To shed theoretical and empirical light on these inconsistencies, the purpose of this paper is to contribute two new perspectives on CE: first, a typology that classifies ethnocentric consumers by the extent to which they support government-controlled protectionism and consumer-controlled protectionism; and second, a configurational (recipe) perspective on the antecedents. Design/methodology/approach – The study applies fuzzy-set qualitative comparative analysis of survey data from 3,859 consumers. The study contrasts the findings with findings using traditional statistical hypotheses testing via multiple regression analysis. Findings – The results reveal several configurations of antecedents that are sufficient for consistently explaining three distinct types of CE. No single antecedent condition is necessary for high CE to occur. Practical implications – The findings help global business strategists in their market entry decisions and in their targeting and segmentation efforts. Originality/value – The authors show the value of asymmetrical thinking about the relationship between CE and its antecedents. The results expand understanding of CE and challenge conventional net-effects thinking about its antecedents
High-energy terahertz pulses from semiconductors pumped beyond the three-photon absorption edge
Ground deformation detection of the greater area of Thessaloniki (Northern Greece) using radar interferometry techniques
In the present study SAR interferometric techniques (stacking of conventional interferograms and Permanent Scatterers), using images from satellites ERS-1 and 2, have been applied to the region of Thessaloniki (northern Greece). The period covered by the images is 1992–2000. Both techniques gave good quantitative and qualitative results. The interferometric products were used to study ground surface deformation phenomena that could be related to the local tectonic context, the exploitation of underground water and sediments compaction. <br><br> The city of Thessaloniki shows relatively stable ground conditions. Subsidence in four locations, mainly in the area surrounding the city of Thessaloniki, has been detected and assessed. Two of the sites (Sindos-Kalochori and Langadhas) were already known from previous studies as subsiding areas, using ground base measurements. On the contrary the other two sites in the northern suburbs of Thessaloniki (Oreokastro) and in the south-east (airport area) were unknown as areas of subsidence. A further investigation based on fieldwork is needed in these two areas. Finally, an attempt to interpret the observed deformation, according to the geological regime of the area and its anthropogenic activities, has been carried out
Surface Oscillations in Overdense Plasmas Irradiated by Ultrashort Laser Pulses
The generation of electron surface oscillations in overdense plasmas
irradiated at normal incidence by an intense laser pulse is investigated.
Two-dimensional (2D) particle-in-cell simulations show a transition from a
planar, electrostatic oscillation at , with the laser
frequency, to a 2D electromagnetic oscillation at frequency and
wavevector . A new electron parametric instability, involving the
decay of a 1D electrostatic oscillation into two surface waves, is introduced
to explain the basic features of the 2D oscillations. This effect leads to the
rippling of the plasma surface within a few laser cycles, and is likely to have
a strong impact on laser interaction with solid targets.Comment: 9 pages (LaTeX, Revtex4), 4 GIF color figures, accepted for
publication in Phys. Rev. Let
Auto-Classifier: A Robust Defect Detector Based on an AutoML Head
The dominant approach for surface defect detection is the use of hand-crafted
feature-based methods. However, this falls short when conditions vary that
affect extracted images. So, in this paper, we sought to determine how well
several state-of-the-art Convolutional Neural Networks perform in the task of
surface defect detection. Moreover, we propose two methods: CNN-Fusion, that
fuses the prediction of all the networks into a final one, and Auto-Classifier,
which is a novel proposal that improves a Convolutional Neural Network by
modifying its classification component using AutoML. We carried out experiments
to evaluate the proposed methods in the task of surface defect detection using
different datasets from DAGM2007. We show that the use of Convolutional Neural
Networks achieves better results than traditional methods, and also, that
Auto-Classifier out-performs all other methods, by achieving 100% accuracy and
100% AUC results throughout all the datasets.Comment: 12 pages, 2 figures. Published in ICONIP2020, proceedings published
in the Springer's series of Lecture Notes in Computer Scienc
From wooded savannah to farmland and settlement: population growth, drought, energy needs and cotton price incentives driving changes in Wacoro, Mali
Land includes vegetation and water bodies and provides the basis for human livelihoods
through primary production, food and freshwater supply, and multiple other ecosystem services. The
last three decades have recorded frequent drought events as well as rapid population growth, which
has often resulted in adverse land use and land cover change (LULCC) in the Sahel of Sub-Saharan
Africa. In order to propose sustainable land management strategies, it is a prerequisite to investigate
the rate of LULCC and its driving factors in specific locations. This study investigated the case of
Wacoro municipality in Mali using a combined approach of remote sensing, Geographic Information
Systems, and focus group discussions. Satellite images and local people’s perceptions on LULCC
and drivers were collected and analyzed for the years 1990, 2000, 2010, and 2020. We found that
the study area faced a rapid decrease in wooded savannah that was degraded and converted to
shrub savannah and later to farmland and settlement. Changes were directly or indirectly related to
the rapid population growth, high cotton price (which encouraged cropland expansion), drought,
firewood extraction, and charcoal production, which was exacerbated by poverty. We suggest
promoting integrated land management strategies that consider current and future livelihood needs
and preserve the environment for the benefits of future generations. New agricultural policies,
such as cotton price incentives, should always be accompanied by an assessment of their potential
environmental impacts and design of adequate mitigation measures
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