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1 – 10 of over 52000
Article
Publication date: 15 June 2015

Qing Wang, Peng Huang, Jiangxiong Li and Yinglin Ke

The purpose of this paper is to propose an innovative method to extend the operating range of the laser tracking system and improve the accuracy and automation of…

Abstract

Purpose

The purpose of this paper is to propose an innovative method to extend the operating range of the laser tracking system and improve the accuracy and automation of boresighting by designing a measurement instrument. Boresighting is a process that aligns the direction of special equipment with the aircraft reference axis. Sometimes the accurate measurement and adjustment of the equipment and the aircraft are hard to achieve.

Design/methodology/approach

The aircraft is moved by an automatic adjustment system which consists of three numerical control positioners. For obtaining the position of the bore axis, an instrument with two measurement points is designed. Based on the multivariate normal distribution hypothesis, an uncertainty evaluation method for the aiming points is introduced. The accuracy of the measurement point is described by an uncertainty ellipsoid. A compensation and calibration method is proposed to decrease the effect of manufacturing error and deflection error by the finite element analysis.

Findings

The experimental results of the boresighting measurement prove that the proposed method is effective and reliable in digital assembly. The measurement accuracy of the angle between the bore axis and the reference axis is about ±0.004°. In addition, the measurement result is mainly influenced by the position error of the instrument.

Originality/value

The results of this study will provide a new way to obtain and control the installation deviation of part in aircraft digital assembly and will help to improve the precision and efficiency. This measurement method can be applied to obtain the axis of a deep blind hole.

Details

Sensor Review, vol. 35 no. 3
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 27 September 2011

Sven Berg, Ulf Jungmar, Jan Lundberg and Pekka Vähäoja

The aim of this study is to determine the variation of the different oil analysis instruments in terms of standard deviation and CV‐values, when measuring samples of fully…

Abstract

Purpose

The aim of this study is to determine the variation of the different oil analysis instruments in terms of standard deviation and CV‐values, when measuring samples of fully formulated hydraulic and gear oils taken from working systems.

Design/methodology/approach

In this investigation, two different spectrometric techniques, inductively coupled plasma‐optical emission spectrometers (ICP‐OES) and rotating disk electrode‐optical emission spectrometers (RDE‐OES), have been studied to determine the instruments' precision of measurement and ability to measure the absolute level of contamination. The study was based on a series of measurements using artificial contamination mixed with oil.

Findings

The ICP has better precision of measurement of the two instruments, but cannot predict the absolute values of contamination when oil samples are only treated by organic solvent dilution if the samples include large or dense particles. It is therefore not too good, with the sample pre‐treatment method used, at detecting wear processes that produce dense/large particles, such as pitting failure. For instance, microwave‐assisted acid digestion could be used for sample pre‐treating to obtain accurate results in that case. It should, however, be able to detect wear mechanisms that produce small particles such as abrasive wear in any case. The ICP has a repeatability value of r=3 percent and a reproducibility value of R=12 percent for contamination levels of between 50 and 400 ppm and r=0.6  and R=2 ppm, respectively, at values below 50 ppm. The RDE cannot predict the absolute value of contamination if this includes large or dense particles if proper sample pre‐treatment is not used. It is therefore not good at detecting wear mechanisms that produces dense/large particles (if the oil samples are not pre‐treated properly) such as pitting but should be able to detect abrasive wear and similar processes that produce small particles in any case. The RDE's precision of measurement is not as good as the ICP, with a reproducibility variation of R=r=25 percent for contamination levels between 20 and 500 ppm and R=r=6 ppm for contamination level below 20 ppm.

Research limitations/implications

Only the effects from lubricating oils are studied.

Practical implications

This study will significantly increase the industrial knowledge concerning measurement precision in particle contamination measurement systems.

Originality/value

No similar study is found.

Details

Industrial Lubrication and Tribology, vol. 63 no. 6
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 1 March 1990

C. Lea

The wetting balance is being used as the focal point to establish a quantitative measurement capability for solderability of electronic components of all configurations…

Abstract

The wetting balance is being used as the focal point to establish a quantitative measurement capability for solderability of electronic components of all configurations. This paper considers the factors influencing solderability measurement that arise directly from the thermal design and construction materials of the wetting balance instrument. The work is illustrated by the differences between the three commercial wetting balances currently manufactured within the European Community.

Details

Soldering & Surface Mount Technology, vol. 2 no. 3
Type: Research Article
ISSN: 0954-0911

Article
Publication date: 1 March 2004

Salvatore Nuccio and Ciro Spataro

This paper concerns with the measurement uncertainty estimation in the analog‐to‐digital conversion‐based instruments. By using an ad hoc developed software tool, the…

382

Abstract

This paper concerns with the measurement uncertainty estimation in the analog‐to‐digital conversion‐based instruments. By using an ad hoc developed software tool, the Monte Carlo method is applied in order to assess the uncertainties associated with the measurement results, overcoming the possible inapplicability of the pure theoretical approach prescribed in the ISO – “Guide to the Expression of Uncertainty in Measurement”. By implementing the software tool in the measurement instruments, the proposed approach can be utilized in order to make the instrument itself able to auto‐estimate the measurement uncertainties.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 23 no. 1
Type: Research Article
ISSN: 0332-1649

Keywords

Book part
Publication date: 12 November 2021

Kaylee Litson and David Feldon

There is currently a great deal of attention in psychometric and statistical methods on ensuring measurement invariance when examining measures across time or populations…

Abstract

There is currently a great deal of attention in psychometric and statistical methods on ensuring measurement invariance when examining measures across time or populations. When measurement invariance is established, changes in scores over time or across groups can be attributed to changes in the construct rather than changes in reaction to or interpretation of the measurement instrument. When measurement in not invariant, it is possible that measured differences are due to the measurement instrument itself and not to the underlying phenomenon of interest. This chapter discusses the importance of establishing measurement invariance specifically in postsecondary settings, where it is anticipated that individuals' perspectives will change over time as a function of their higher education experiences. Using examples from several measures commonly used in higher education research, the concepts and processes underlying tests of measurement invariance are explained and analyses are interpreted using data from a US-based longitudinal study on bioscience PhD students. These measures include sense of belonging over time and across groups, mental well-being over time, and perceived mentorship quality over time. The chapter ends with a discussion about the implications of longitudinal and group measurement invariance as an important conceptual property for moving forward equitable, reproducible, and generalizable quantitative research in higher education. Invariance methods may further be relevant for addressing criticisms about quantitative analyses being biased toward majority populations that have been discussed by critical theorists engaging quantitative research strategies.

Details

Theory and Method in Higher Education Research
Type: Book
ISBN: 978-1-80262-441-0

Keywords

Article
Publication date: 27 September 2011

Sven Berg, Ulf Jungmar, Jan Lundberg and Pekka Vähäoja

The aim of this study is to determine the variation of the different oil analysis instruments in terms of standard deviation and CV‐values, when measuring samples of fully…

Abstract

Purpose

The aim of this study is to determine the variation of the different oil analysis instruments in terms of standard deviation and CV‐values, when measuring samples of fully formulated hydraulic and gear oils taken from working systems.

Design/methodology/approach

In this investigation two different spectrometric techniques, ICP‐OES and RDE‐OES, have been studied to determine the instruments' precision of measurement and ability to measure the absolute level of contamination.

Findings

The ICP has better precision of measurement of the two instruments, but cannot predict the absolute values of contamination when oil samples are only treated by organic solvent dilution if the samples include large or dense particles. It is therefore not too good, with the sample pre‐treatment method used, at detecting wear processes that produce dense/large particles, such as pitting failure. For instance, microwave‐assisted acid digestion could be used for sample pre‐treating to obtain accurate results in that case. It should, however, be able to detect wear mechanisms that produce small particles such as abrasive wear in any case: the ICP has a repeatability value of r=3 per cent and a reproducibility value of R=12 per cent for contamination levels of between 50‐400 PPM and r=0.6 PPM and R=2 PPM, respectively, at values below 50 PPM; the RDE cannot predict the absolute value of contamination if this includes large or dense particles if proper sample pre‐treatment is not used. It is therefore not good at detecting wear mechanisms that produce dense/large particles (if the oil samples are not pre‐treated properly) such as pitting but should be able to detect abrasive wear and similar processes that produce small particles in any case; the RDE's precision of measurement is not as good as the ICP, with a reproducibility variation of R=r=25 per cent for contamination levels between 20‐500 PPM and R=r=6 PPM for contamination level below 20 PPM.

Research limitations/implications

Measuring only on fully formulated oils from hydraulic and gear systems.

Practical implications

The study will be of significant support regarding industrial interpretation of measurement results from the most common oil particle measurement methods.

Originality/value

No other similar studies are known.

Details

Industrial Lubrication and Tribology, vol. 63 no. 6
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 1 November 2000

Juan Carlos Bou Llusar and César Camisón Zornoza

This paper verifies the adequacy of perceived quality measurement instruments by comparing the SERVPERF and EP methods. After a discussion of the differences between the…

2781

Abstract

This paper verifies the adequacy of perceived quality measurement instruments by comparing the SERVPERF and EP methods. After a discussion of the differences between the two methods, a quality perception measurement instrument for the company is developed and applied to a sample of ceramic company clients. The methods are compared by analyzing the multitrait‐multimethod matrix using the structural equation model methodology. Results indicate that SERVPERF has greater reliability, greater convergent and discriminant validity, explains variance more completely, and consequently introduces less bias.

Details

International Journal of Quality & Reliability Management, vol. 17 no. 8
Type: Research Article
ISSN: 0265-671X

Keywords

Article
Publication date: 6 May 2014

Kristel Wouters and Jeroen Maesschalck

– The aim of this study was to develop a valid and reliable measurement instrument for organizational culture on the basis of grid-group cultural theory (GGCT).

1139

Abstract

Purpose

The aim of this study was to develop a valid and reliable measurement instrument for organizational culture on the basis of grid-group cultural theory (GGCT).

Design/methodology/approach

The study consisted of three phases. In a first phase, the literature was reviewed and experts on GGCT were consulted in order to design an item pool for the typology. In a second phase, a pilot study was done in two organizations of the Belgian federal government to evaluate this original item pool. The third phase consisted of the actual data gathering in seven organizations within the Belgian federal government.

Findings

The study showed that it is possible to measure organizational culture based on GGCT. The authors used confirmatory factor analysis to examine the underlying structure of the data and found support for the existence of four culture scales. Scale reliabilities in the third phase of the study were satisfactory and ranged between 0.703 and 0.848.

Research limitations/implications

The current research was not specifically designed to evaluate content validity. Further research is needed to explore this issue. It would also be interesting to develop a GGCT-based measurement instrument for the team level.

Practical implications

The measurement instrument can be used by practitioners to describe and assess their organizational culture.

Originality/value

This study introduces a novel way to measure organizational culture, using a promising theoretical framework.

Details

International Journal of Organizational Analysis, vol. 22 no. 2
Type: Research Article
ISSN: 1934-8835

Keywords

Article
Publication date: 22 October 2020

Christy M.K. Cheung, Randy Yee Man Wong and Tommy K.H. Chan

Online disinhibition is one of the key factors leading to the occurrence of cyberaggression, cyberbullying and various forms of deviant behaviors in the online…

Abstract

Purpose

Online disinhibition is one of the key factors leading to the occurrence of cyberaggression, cyberbullying and various forms of deviant behaviors in the online environment. To understand the composition of online disinhibition, this study aims to conceptualize online disinhibition and develop a measurement instrument for online disinhibition.

Design/methodology/approach

We followed a rigorous procedure to develop and validate the multidimensional instrument of online disinhibition in three phases: item generation, measurement development and instrument testing.

Findings

We developed a 23-item online disinhibition scale and identified six key dimensions: dissociative anonymity, invisibility, asynchronicity, solipsistic introjections, dissociative imagination and minimization of authority.

Practical implications

The online disinhibition instrument is an accessible and easily administered measure that can be used as a checklist for systems designers and administrators to evaluate the level of online disinhibition among users. It offers systems design information on how to prevent and combat online deviant behaviors on platforms.

Originality/value

This work provides a rich conceptualization of an online disinhibition instrument that can serve as a springboard for future work to understand online deviant behaviors. The newly developed measurement instrument of online disinhibition also adds to the repository of rigorous research scales in this area.

Article
Publication date: 1 September 2002

M. Saadat and L. Cretin

This paper results from research carried out to survey the various large commercial aerospace engineering component measurement systems. The commercial aircraft…

1205

Abstract

This paper results from research carried out to survey the various large commercial aerospace engineering component measurement systems. The commercial aircraft manufacturing industry is special due to the size of the components involved. Accuracy constraints remain very close, despite the size, and therefore accurate methods of measurement are necessary to control the quality of the final product. A survey of various current methods of measurement for such components is presented. These methods are based around three main principles: theodolites, photogrammetry, and laser technology. Each method has its own advantages and disadvantages in terms of accuracy, repeatability, range and cost. It is also often necessary to consider what each technique provides in terms of data storage and analysis. Most techniques use computer‐based systems to store results and perform various calculations. These systems also have their own requirements in terms of the environment in which they are used. It is important to consider whether a particular system can be installed in an area suitable to measure the required component, as well as ensuring that the stability requirements are met. In this paper the principles and characteristics of conventional optical tooling, electronic triangulation, electronic trilateration, photogrammetry, laser trackers, and laser scanners are reviewed.

Details

Sensor Review, vol. 22 no. 3
Type: Research Article
ISSN: 0260-2288

Keywords

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