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  • Author: Jan Berka x
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High temperature alloys stability testing in impure helium

Abstract

Within the national and international research program of materials for advanced nuclear reactors Czech organizations contributed with several tests of metallic alloys. The specimens of the alloys were first exposed in the long term (up to 1500 hours) in simulated advanced gas cooled reactor coolant environment at 750-900 °C. After exposure the degradation of tested materials was explored, especially changes in material microstructure, corrosion damage and corrosion layer composition and in some cases also changes in mechanical properties were observed. In this paper selected results of exposure tests in high temperature helium of alloy 800 H, austenitic steel 316L and high-temperature nickel alloys are presented.

Open access
Quiz-Based Evaluation of Machine Translation

Quiz-Based Evaluation of Machine Translation

This paper proposes a new method of manual evaluation for statistical machine translation, the so-called quiz-based evaluation, estimating whether people are able to extract information from machine-translated texts reliably. We apply the method to two commercial and two experimental MT systems that participated in WMT 2010 in English-to-Czech translation. We report inter-annotator agreement for the evaluation as well as the outcomes of the individual systems. The quiz-based evaluation suggests rather different ranking of the systems compared to the WMT 2010 manual and automatic metrics. We also see that overall, MT quality is becoming acceptable for obtaining information from the text: about 80% of questions can be answered correctly given only machine-translated text.

Open access
Addicter: What Is Wrong with My Translations?

Addicter: What Is Wrong with My Translations?

We introduce Addicter, a tool for Automatic Detection and DIsplay of Common Translation ERrors. The tool allows to automatically identify and label translation errors and browse the test and training corpus and word alignments; usage of additional linguistic tools is also supported. The error classification is inspired by that of Vilar et al. (2006), although some of their higher-level categories are beyond the reach of the current version of our system. In addition to the tool itself we present a comparison of the proposed method to manually classified translation errors and a thorough evaluation of the generated alignments.

Open access
Testování mechanických vlastností Inconelu 713 a 738 pro pokročilé reaktory

Abstract

Mezi kovové konstrukční materiály pro komponenty pokročilých plynem chlazených reaktorů patří niklové superslitiny Inconel 713 a 738. V rámci projektu aplikovaného výzkumu řešeného na VŠCHT Praha a CV Řež byly testovány mechanické vlastnosti těchto slitin ve výchozím stavu a po expozici vzorků v heliu obsahujícím stopové nečistoty (CO, H2, CH4, H2O) při teplotě 900 °C po dobu 1000 hod. Vzorky testovaných slitin byly vyrobeny: a) z původního litého materiálu (virgin), b) přepracovaného materiálu z výroby (revert 100R) a c) materiálu získaného slitím těchto materiálů v poměru 50V/50R. K určení mechanických vlastností materiálů po expozicích byly provedeny tahové zkoušky a strukturní analýza pomocí SEM. Porovnány byly změny vlastností po expozici jednotlivých testovaných slitin i stejné slitiny vyrobené různými postupy. Zatímco mez kluzu a mez pevnosti poklesly u Inconelu 713 jen zlehka, u Inconelu 738 poklesly výrazně. Stav 50V/50R vykazoval lepší mechanické vlastnosti než stav revert 100R.

Open access