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Article
Publication date: 18 April 2008

J. Rodrigues Dias and Paulo Infante

The purpose of this paper is to investigate a new sampling methodology previously proposed for systems with a known lifetime distribution: the Predetermined Sampling Intervals…

1194

Abstract

Purpose

The purpose of this paper is to investigate a new sampling methodology previously proposed for systems with a known lifetime distribution: the Predetermined Sampling Intervals (PSI) method.

Design/methodology/approach

The methodology is defined on basis of system hazard cumulative rate, and is compared with other approaches, particularly those whose parameters may change in real time, taking into account current sample information.

Findings

For different lifetime distributions, the results obtained for adjusted average time to signal (AATS) using a control chart for the sample mean are presented and analysed. They demonstrate the high degree of statistical performance of this sampling procedure, particularly when used in systems with an increasing failure rate distribution.

Practical implications

This PSI method is important from a quality and reliability management point of view.

Originality/value

This methodology involves a process by which sampling instants are obtained at the beginning of the process to be controlled. Also this new approach allows for statistical comparison with other sampling schemes, which is a novel feature.

Details

International Journal of Quality & Reliability Management, vol. 25 no. 4
Type: Research Article
ISSN: 0265-671X

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Article
Publication date: 9 January 2009

J. Rodrigues Dias

The main purpose of this paper is to present an optimal economic solution for a different adaptive sampling method that is highly intuitive in its nature: the normal sampling…

811

Abstract

Purpose

The main purpose of this paper is to present an optimal economic solution for a different adaptive sampling method that is highly intuitive in its nature: the normal sampling intervals (NSI) method.

Design/methodology/approach

Considering costs associated with sampling, false alarms and imperfect operation per unit of time, the paper presents a new optimal simple solution that minimizes the expected total cost per cycle. This NSI method involves the density function of the standard normal variable, assuming that the distribution of averages is normal or approximately normal (on the basis of the central limit theorem). It depends on a single scale parameter while other methods depend on various parameters.

Findings

When this expected total cost associated with the new NSI method is compared with the fixed (FSI) and variable sampling intervals (VSI) methods, in identical situations, it may be seen that, in general, it is lower (and may be much lower) and, also, that it is lower for a wider range of changes in terms of quality. This feature is particularly important because, in practice, the degree of change that occurs is not known, so this greater robustness in terms of performance is relevant.

Practical implications

In the practice, the minimization of total expected costs is an important point of view in the life of companies, concerning quality and statistical process control (SPC). The paper holds that this NSI method has a great degree of potential, in particular considering that in industrial processes there is growing recourse to automated systems for the collection and analysis of samples, and thus there are no special additional costs associated with labour, management or administration.

Originality/value

The great advantages of this NSI method are its highly intuitive nature and the fact that it enables generally much better results to be achieved as compared with the use of FSI and VSI methods. An optimal economic solution for this NSI method is presented in this paper.

Details

International Journal of Quality & Reliability Management, vol. 26 no. 1
Type: Research Article
ISSN: 0265-671X

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Article
Publication date: 29 April 2014

Manuel do Carmo, Paulo Infante and Jorge M Mendes

– The purpose of this paper is to measure the performance of a sampling method through the average number of samples drawn in control.

1127

Abstract

Purpose

The purpose of this paper is to measure the performance of a sampling method through the average number of samples drawn in control.

Design/methodology/approach

Matching the adjusted average time to signal (AATS) of sampling methods, using as a reference the AATS of one of them the paper obtains the design parameters of the others. Thus, it will be possible to obtain, in control, the average number of samples required, so that the AATS of the mentioned sampling methods may be equal to the AATS of the method that the paper uses as the reference.

Findings

A more robust performance measure to compare sampling methods because in many cases the period of time where the process is in control is greater than the out of control period. With this performance measure the paper compares different sampling methods through the average total cost per cycle, in systems with Weibull lifetime distributions: three systems with an increasing hazard rate (shape parameter β=2, 4 and 7) and one system with a decreasing failure rate (β=0, 8).

Practical implications

In a usual production cycle where the in control period is much larger than the out of control period, particularly if the sampling costs and false alarms costs are high in relation to malfunction costs, the paper thinks that this methodology allows us a more careful choice of the appropriate sampling method.

Originality/value

To compare the statistical performance between different sampling methods using the average number of samples need to be inspected when the process is in control. Particularly, the paper compares the statistical and economic performance between different sampling methods in contexts not previously considered in literature. The paper presents an approximation for the average time between the instant that failure occurs and the first sample with the process out of control, as well.

Details

International Journal of Quality & Reliability Management, vol. 31 no. 5
Type: Research Article
ISSN: 0265-671X

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Article
Publication date: 12 October 2010

694

Abstract

Details

International Journal of Quality & Reliability Management, vol. 27 no. 9
Type: Research Article
ISSN: 0265-671X

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Article
Publication date: 24 October 2022

Rogério Lopes, Francisco Barros, Francisco Q. de Melo, Nuno V. Ramos, Rafael Cunha, Ricardo Maia, Rui Rodrigues, M.P.L. Parente and P.M.G. Moreira

The vehicle´s body front pillar should absorb most of the striker kinetic energy, while only a fraction of that is absorbed by the door structure. This study aims to discuss the…

121

Abstract

Purpose

The vehicle´s body front pillar should absorb most of the striker kinetic energy, while only a fraction of that is absorbed by the door structure. This study aims to discuss the aforementioned issue. In this test the striker is a virtual entity. Six uniaxial strain gauges are installed throughout the door. Additionally, contactless 3D digital image correlation (DIC) allows to assess the major door panel’s continuous deformation and strain fields.

Design/methodology/approach

A coach is a large and heavy long-distance passenger transport vehicle. Their structural certification, classifies coaches as M3 Class III vehicles. New coach structures’ designs need analyses of each sub-system for critical pre-validation of the entire structure, aiming driver and passenger carrier safety. Also, a thorough examination due to increased travel speed is needed.

Findings

Experimental pseudo-dynamic (PSD) results were compared and validated using finite element method (FEM) with two pieces of distinct FEM software (Abaqus® and PamCrash®). The time dependent solution was carried out by explicit techniques. Results by FEM and PSD test showed good agreement, evidencing the reliability of the tools selected. Results by PamCrash® were closer to the experimental data.

Practical implications

R-29 is truck-only regulation, however can be adapted to coaches in case of a frontal collision. The present work focuses on the impact behavior of the passenger front door subsystem.

Originality/value

As a first validation the entire structure, the behavior of a vehicle door, under in-plane impacts was studied. The corresponding deformation energy absorbed by the frontal passenger coach door under virtual impacts of a swinging striker was assessed using a PSD approach.

Details

International Journal of Structural Integrity, vol. 14 no. 1
Type: Research Article
ISSN: 1757-9864

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Article
Publication date: 5 October 2015

Shi Zhang, Yun Zhang, Zhigao Huang, Huamin Zhou and Jianhui Li

– The purpose of this paper is to study the inter-element coupling effect of membrane and plate components between two adjacent shells occurring on the common boundary.

157

Abstract

Purpose

The purpose of this paper is to study the inter-element coupling effect of membrane and plate components between two adjacent shells occurring on the common boundary.

Design/methodology/approach

In this paper, three triangular flat shells developed by combining an excellent membrane element (OPT) with three outstanding plate bending elements (DKT, RDKTM and DST-BK), respectively, are used to study this phenomenon. Benchmark tests are implemented to evaluate the performance of three selected plate elements and the formulated flat shells.

Findings

The inter-element coupling effect of membrane and plate components belonging, respectively, to two adjacent shells deteriorate the performance of shells. Therefore, a shell’s performance cannot be guaranteed certainly by the superimposed membrane and plate behaviors.

Practical implications

The “order matching” criterion is proposed to explain this phenomenon and it is concluded that the flat shell that follows this criterion explicitly may alleviate or even overcome the inter-element coupling effect.

Originality/value

Previous studies mainly focus on formulation of high-performance membrane and plate elements. However, the inter-element coupling effect of membrane and plate components between two adjacent shells occurring on the common boundary, has attracted less attention. Thorough benchmark tests for three flat shells are implemented to investigate the phenomenon. The results shows that the inter-element coupling effect deteriorates the performance of shells. And the “order matching” criterion is proposed to explain this phenomenon and it is concluded that the flat shell that follows this criterion explicitly may alleviate or even overcome the inter-element coupling effect.

Details

Engineering Computations, vol. 32 no. 7
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 21 January 2022

Angélica Vasconcelos, Alan Sangster and Lúcia Lima Rodrigues

The main aim of this paper is to illustrate the importance of avoiding Whig interpretations in historical research. It does so by highlighting examples of what may occur when this…

472

Abstract

Purpose

The main aim of this paper is to illustrate the importance of avoiding Whig interpretations in historical research. It does so by highlighting examples of what may occur when this is not done. The paper also aims to promote interdisciplinarity, in the form of working with those from other disciplines, as a means to avoid this occurring.

Design/methodology/approach

This paper includes an in-depth study of the bookkeeping and financial reporting of two 18th century Portuguese state-sponsored companies using archival sources. The companies were selected because of conflicting insights across disciplines concerning the quality of their bookkeeping and financial reporting – historians have been very critical, while accounting historians have seen little wrong. These differences of opinion have never previously been investigated. The authors demonstrate how information was distributed among the account books and other records of the two companies. The approach adopted enabled a reader to fully understand the recorded economic events. The authors also present and explain the procedures, criteria and accounting terminology used in their annual reports.

Findings

This paper demonstrates how easy is to inadvertently adopt a Whig interpretation of accounting history when the focus of interest is something of which the principal researcher has insufficient understanding or expertise. It also illustrates how important it is to embrace interdisciplinarity by working with those from other discipline to avoid doing so.

Research limitations/implications

The conclusions from the case study are company-specific and cannot be generalised beyond those companies. However, the implications of this study go beyond the companies in its illustration of the importance of fully understanding historical evidence within its own context.

Originality/value

This paper unveils primary archival sources never previously presented in the literature. It also contributes to the literature by providing an evidence-based justification for the calls previously made to accounting historians to study accounting in its social context and engage with historians from other disciplines.

Details

Accounting, Auditing & Accountability Journal, vol. 35 no. 6
Type: Research Article
ISSN: 0951-3574

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Article
Publication date: 3 October 2016

António Dias, Lúcia Lima Rodrigues and Russell Craig

This paper investigates the effect of the global financial crisis (GFC) on the level of corporate social responsibility disclosures (CSRD) in the annual report and/or CSR report…

2437

Abstract

Purpose

This paper investigates the effect of the global financial crisis (GFC) on the level of corporate social responsibility disclosures (CSRD) in the annual report and/or CSR report of 36 major listed Portuguese companies in each of the years 2005, 2008 and 2011.

Design/methodology/approach

The analysis is framed principally by stakeholder theory. Data were explored using thematic content analysis and an index of disclosure calculated by year, industry type (consumer proximity versus environment sensitivity) and category of information.

Findings

Before the GFC, Portuguese listed companies increased their CSRD practices significantly. During the crisis, there was a slight decrease in CSRD. However, this was not as pronounced, as it would otherwise have been because it was counteracted by increased disclosures of company interactions with society, particularly in matters of corruption prevention and community engagement. CSRD was higher for companies with high consumer proximity but did not appear to be influenced by companies’ level of environmental sensitivity.

Originality/value

The results reveal a strong concern by companies for stakeholder management (particularly in respect of community relations) in a period of financial crisis. This study highlights the effect of a company’s proximity to consumers on levels of CSRD.

Details

Social Responsibility Journal, vol. 12 no. 4
Type: Research Article
ISSN: 1747-1117

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Article
Publication date: 2 November 2018

António Dias, Lúcia Lima Rodrigues, Russell Craig and Maria Elisabete Neves

Corporate Social Responsibility (CSR) literature has focused mainly on larger firms. Only recently has discussion of the engagement of small and medium-sized enterprises (SMEs) in…

2280

Abstract

Purpose

Corporate Social Responsibility (CSR) literature has focused mainly on larger firms. Only recently has discussion of the engagement of small and medium-sized enterprises (SMEs) in CSR emerged in research studies. Here we contribute to that growing discussion of CSR in SMEs by analyzing the disclosure practices of 57 Portuguese companies of different sizes (small, medium, large).

Design/methodology/approach

We use stakeholder theory to identify the stakeholders that SMEs and large firms prioritize. By means of thematic content analysis and an index of disclosure (calculated according to company type and stakeholder type) we analyze whether business characteristics influence CSR disclose strategies.

Findings

Companies give priority to CSR activities that are directly related to maintaining business and achieving economic results. CSR disclosure practices of SMEs and large companies do not differ significantly. However, larger companies disclose more information on Environment and Society. Companies who are closer to consumers disclose more information on Customers, Community and Society. The act of assuring a CSR report drives system improvements and extended CSR disclosure.

Research limitations/implications

We recognize that it is difficult to compare CSR in Small and large enterprises. For this reason, we have developed a methodology based on the most basic aspects of the CSRD, and therefore applicable without distinction to large and small companies.

Practical implications

A framework to evaluate the CSRD of SMEs was developed. We identify CSR indicators divided in five dimensions (customers, employees, environment, community and society) that are applicable to firms of all sizes.

Originality/value

This study extends knowledge of CSR by comparing the disclosure practices of SMEs and large (listed and un-listed) Portuguese companies. This study takes account of the particularities of SMEs and other fundamental business characteristics using a replicable assessment framework.

Details

Social Responsibility Journal, vol. 15 no. 2
Type: Research Article
ISSN: 1747-1117

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Book part
Publication date: 25 November 2019

Filomena Santos and Rita Dias

In the twenty-first century, the family has been turning towards a greater plurality of training paths, situations, family and parental arrangements. However, despite changes in…

Abstract

In the twenty-first century, the family has been turning towards a greater plurality of training paths, situations, family and parental arrangements. However, despite changes in legislation, values, representations and practices, the word family remains inexorably associated with the heterosexual bi-parental model. This paper aims to contribute to the knowledge of the family dynamics of non-heterosexual people, mainly concerning the process of transition to parenting, in relation to family changes in Portuguese society. To do so this study aims to analyze four in-depth interviews1 with young adults, women and men who have a homoconjugality relationship and a project of parenting in mind.

Based on a qualitative methodology the study intends to discuss issues related to the challenge of heteronormativity, equality within the couple, projects and gender representations of parenthood and in particular what it means for the men and women interviewed, to be a father and to be a mother in a same sex couple and how they project themselves as fathers and mothers.

The study discusses all these issues always in relation to the biographical trajectories, the history and life as a couple and the structural and individual resources, such as school and professional qualifications. It also analyzes the main difficulties experienced in revealing their sexuality to the significant others and the difficulties / strategies they anticipate in relation to the parenting project.

The authors conclude that female interviewees show greater independence of a male figure in relation to their parental projects and anticipate less difficulty in their parental skills compared with the gay man interviewed.

To analyze the dynamics of parenting in same-sex couples, this study also points out to the need to construct a model of analysis capable of articulating structural factors, such as job insecurity and heteronormativity, biographies and individual resources and profiles of conjugal interactions.

Details

Childbearing and the Changing Nature of Parenthood: The Contexts, Actors, and Experiences of Having Children
Type: Book
ISBN: 978-1-83867-067-2

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