Search results for "testing."

Comparison of Post-Weld Treatment of High-Strength Steel Welded Joints in Medium Cycle Fatigue

2010

This paper presents a comparison of three post-weld treatments for fatigue life improvement of welded joints. The objective is to determine the most suitable post-weld treatment for implementation in mass production of certain crane components manufactured from very high-strength steel. The processes investigated are: burr grinding, TIG dressing and ultrasonic impact treatment. The focus of this investigation is on the so-called medium cycle area, i.e. 10 000-500 000 cycles and very high stress ranges. In this area of fatigue design, the use of very high strength steel becomes necessary, since the stress range can exceed the yield-strength of ordinary structural steel, especially when consi…

Editorial: Scale Development and Score Validation

2020

DigiTala research project : automatic speech recognition in assessing L2 speaking

2020

In this article, we discuss the premise of assessing oral language skills with the help of automatic speech recognition. We present the main goals and working methods in DigiTala project (2019–2023) – a research project between University of Helsinki, Aalto University and University of Jyväskylä that aims at developing a digital tool for assessing and practicing oral language skills. Ultimately, this digital tool would enable implementing tasks measuring oral skills into the language tests of the Matriculation Examination. nonPeerReviewed

Why is the hypothetico-deductive (H-D) method in information systems not an H-D method?

2020

The hypothetico-deductive (H-D) method is reported to be common in information systems (IS). In IS, the H-D method is often presented as a Popperian, Hempelian, or natural science method. However, there are many fundamental differences between what Popper or Hempel actually say and what the alleged H-D method per Hempel or per Popper means in IS. To avoid possible misunderstanding and conceptual confusion about the basic philosophical concepts, we explain some of these differences, which are not mentioned in IS literature describing the H-D model. Due to these distinctive differences, the alleged H-D method per Hempel or per Popper in IS cannot be regarded as the H-D model per Hempel or per…

A methodology for the control of the residual lifetimes of carbon fibre reinforced composite pressure vessels

2005

International audience; Pressure vessels must be periodically proof tested. Traditional techniques for metal vessels are inapplicable for composite vessels as the latter do not break by crack propagation so that the reasoning behind the traditional testing procedures is not appropriate. Damage accumulation leading to the degradation of a composite vessel is by fibre failure. Fibres show a wide distribution in strengths and loading a composite inevitably breaks some. The method which has been developed is supported by an analysis of delayed fibre failure due to the relaxation of the resin around fibre breaks. This provokes overloading of intact fibres neighbouring breaks. The time until a cr…

Corrigendum: ExGUtils: A Python Package for Statistical Analysis With the ex-Gaussian Probability Density

2018

Two‐sample problems in statistical data modelling

2010

A common problem in mathematical statistics is to check whether two samples differ from each other. From modelling point of view it is possible to make a statistical test for the equality of two means or alternatively two distribution functions. The second approach allows to represent the two‐sample test graphically. This can be done by adding simultaneous confidence bands to the probability‐probability (P — P) or quantile‐quantile (Q — Q) plots. In this paper we compare empirically the accuracy of the classical two‐sample t‐test, empirical likelihood method and several bootstrap methods. For a real data example both Q — Q and P — P plots with simultaneous confidence bands have been plotted…

Fibre fragment distribution in a single-fibre composite tension test

2001

Abstract Single fibre fragmentation tests are performed for brittle fibres with Weibull strength distribution and different surface treatments. The fragmentation process is modelled and closed-form expressions for break spacing distribution are obtained. The model accounts for the effect of finite fibre length on the initial fragmentation as well as for break interaction on the advanced fragmentation stage. It is assumed that the exclusion zone due to fibre–matrix interface failure and stress recovery in the fibre is linearly dependent on the applied load. This assumption is validated experimentally. The derived theoretical average fragment length dependence on applied load is used to deter…

Analysis of a database to predict the result of allergy testing in vivo in patients with chronic nasal symptoms.

2014

Background This article uses the logistic regression model for diagnostic decision making in patients with chronic nasal symptoms. We studied the ability of the logistic regression model, obtained by the evaluation of a database, to detect patients with positive allergy skin-prick test (SPT) and patients with negative SPT. The model developed was validated using the data set obtained from another medical institution. Methods The analysis was performed using a database obtained from a questionnaire administered to the patients with nasal symptoms containing personal data, clinical data, and results of allergy testing (SPT). All variables found to be significantly different between patients w…

Inventory of Testing Ideas and Structuring of Testing Terms

2013

This is a preprint of the paper submitted for publication in "Baltic Journal of Modern Computing".