Bin Nie, Diqing Liu, Xiaohui Liu and Wenjing Ye
The purpose of this paper is to propose a new non-parametric phase I control chart for the problem of non-linear profile outlier detection.
Abstract
Purpose
The purpose of this paper is to propose a new non-parametric phase I control chart for the problem of non-linear profile outlier detection.
Design/methodology/approach
The proposed non-parametric method is based on a modified Hausdorff distance, which does not require a restrictive assumption on the form of profiles. By obtaining the distance between each profile and the baseline profile, the authors introduced an iterative optimization clustering algorithm to identify outliers by clustering distances.
Findings
The simulation results show that the proposed method can distinguish outliers for structural changes of non-linear profiles. The authors also present a real industrial case example to highlight how practitioners can implement and make use of the proposed control chart in outlier detection applications, and it achieves higher accuracy in the outlier detection of complex profiles.
Practical implications
The research results of this paper can be applied to any manufacturing or service system whose quality characteristics are characterized by non-linear profiles. This new approach provides quality practitioners a better decision-making tool for non-linear profile outlier detection.
Originality/value
Due to the complexity of real-world applications, the non-linear profiles monitoring problem is yet to be addressed. However, the related research still remains rare. And the authors’ proposed non-linear profile control chart, which does not require a restrictive assumption on the form of profiles, shows its applicability and superiority in simulation study and real-world case.
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Hamidreza Izadbakhsh, Rassoul Noorossana and Seyed Taghi Akhavan Niaki
The purpose of this paper is to apply Poisson generalized linear model (PGLM) with log link instead of multinomial logistic regression to monitor multinomial logistic profiles in…
Abstract
Purpose
The purpose of this paper is to apply Poisson generalized linear model (PGLM) with log link instead of multinomial logistic regression to monitor multinomial logistic profiles in Phase I. Hence, estimating the coefficients becomes easier and more accurate.
Design/methodology/approach
Simulation technique is used to assess the performance of the proposed algorithm using four different control charts for monitoring.
Findings
The proposed algorithm is faster and more accurate than the previous algorithms. Simulation results also indicate that the likelihood ratio test method is able to detect out-of-control parameters more efficiently.
Originality/value
The PGLM with log link has not been used to monitor multinomial profiles in Phase I.
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Many scientists encounter foreign‐language publications whose subjects are of particular relevance to them. Their problem then lies in finding whether a translation is available…
Abstract
Many scientists encounter foreign‐language publications whose subjects are of particular relevance to them. Their problem then lies in finding whether a translation is available and if not, where linguistic help may be found. The most useful sources of information about translations have been surveyed with particular emphasis on their strengths and weaknesses, and with examples pertinent to the metals industry. It has been demonstrated that very little effort is required to be 95 per cent certain of the availability, or otherwise, of a translation of a particular paper.
Eleonora Pantano and Kim Willems
Traditional sets of attributes characterizing shopping centres need to be updated to relate to new specific consumers' needs and choices, to ensure the survival of shopping…
Abstract
Traditional sets of attributes characterizing shopping centres need to be updated to relate to new specific consumers' needs and choices, to ensure the survival of shopping centres. To this end, this chapter revisits shopping centres’ attributes in the light of consumers' choices of actual centres, taking into account the recent increasing role of technologies, leisure activities and changes in consumer behaviour. In doing so, we aim to improve perceptions of modernity and help to regenerate (or at least mitigate the decline of) shopping centres. Specifically, the new set of attributes include appearance (external appearance), convenience, entertainment and leisure activities, memorable experiences, green place and policy, image (modern image), price, service, size and technology.
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Simone Pettigrew and Melanie Pescud
The purpose of this paper is to evaluate the ability of a social marketing intervention to provide families with specific nutrition information, stimulate family discussions on…
Abstract
Purpose
The purpose of this paper is to evaluate the ability of a social marketing intervention to provide families with specific nutrition information, stimulate family discussions on the topic of nutrition, and encourage parents to make changes in their child‐feeding practices.
Design/methodology/approach
A postcard intervention was administered to families with children aged five to 12 years at three primary schools in Western Australia. Approximately two months later, an evaluation questionnaire was administered to the three intervention schools and a control school.
Findings
In total, 229 usable questionnaires were returned, representing a 22 percent response rate. In the intervention schools, almost half of the respondents reported discussing the contents of the postcards with their children and a third reported giving the cards to their children to read. The intervention was successful in encouraging a majority (60 percent) of respondents to make at least one favourable change to their child‐feeding practices, in line with the recommendations provided.
Originality/value
The study demonstrated that a simple and cost‐effective social marketing intervention can encourage family discussions on the topic of nutrition and favourably influence parents' child‐feeding practices.
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The purpose of this paper is to demonstrate the application of the control chart procedure to monitor the characteristics whose profile over time resembles a set of connected line…
Abstract
Purpose
The purpose of this paper is to demonstrate the application of the control chart procedure to monitor the characteristics whose profile over time resembles a set of connected line segments.
Design/methodology/approach
Fit a regression spline model by taking the subgroup average of the characteristic as response variable and time as the explanatory variable. Then monitor the response variable using the regression spline control chart with the fitted model as center line and upper and lower control limits at three standard deviation units of the response variable above and below the center line.
Findings
The proposed chart is successfully deployed to monitor the daily response time profile of a client server of an application support process. The chart ensured the stability of the process as well as detected the assignable cause leading to the slowing down of the server performance.
Practical implications
The methodology can be used to monitor any characteristics whose performance profile over time resembles a set of connected line segments. Some of the examples are the consumption profile of utility providers like power distribution companies, usage profiles of telecom networks, loading profile of airline check-in process, e-commerce websites, etc.
Originality/value
To the best of the author’s knowledge, construction of control charts using regression spline is new. The usage of the control chart to monitor the performance characteristics which exhibits a nonlinear profile over time is also rare.
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Sofia Holguin and Olga Kosheleva
Usually, people's interests do not match perfectly. So when several people need to make a joint decision, they need to compromise. The more people one has to coordinate the…
Abstract
Purpose
Usually, people's interests do not match perfectly. So when several people need to make a joint decision, they need to compromise. The more people one has to coordinate the decision with, the fewer chances that each person's preferences will be properly taken into account. Therefore, when a large group of people need to make a decision, it is desirable to make sure that this decision can be reached by dividing all the people into small-size groups so that this decision can reach a compromise between the members of each group. The study's objective is to analyze when such a compromise is possible.
Design/methodology/approach
In this paper, the authors use a recent mathematical result about convex sets to analyze this problem and to come up with an optimal size of such groups.
Findings
The authors find the smallest group size for which a joint decision is possible. Specifically, the authors show that in situations where each alternative is characterized by n quantities, it is possible to have a joint decision if the participants are divided into groups of size n -- and, in general, no such decision is possible if the participants are divided into groups of size n -- 1.
Originality/value
The main novelty of this paper is that, first, it formulates the problem, which, to the best of the authors’ knowledge, was never formulated in this way before, and, second, that it provides a solution to this problem.
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I could quote many more examples of linguistic difficulties facing the managers, research workers, salesmen and other staff for whom we provide a service. You are all familiar…
Abstract
I could quote many more examples of linguistic difficulties facing the managers, research workers, salesmen and other staff for whom we provide a service. You are all familiar with the problem. Some of you cope with it using the resources at your disposal, sometimes scanty, sometimes considerable. Others would like to help their colleagues but are deterred, and I can almost hear them say ‘Am I taking on more than I can cope with? How do I set about it? Can I do it at a time when my budget is limited and it is a struggle to maintain services and standards, let alone embark upon a new venture?’
Ahmad Hakimi, Amirhossein Amiri and Reza Kamranrad
The purpose of this paper is to develop some robust approaches to estimate the logistic regression profile parameters in order to decrease the effects of outliers on the…
Abstract
Purpose
The purpose of this paper is to develop some robust approaches to estimate the logistic regression profile parameters in order to decrease the effects of outliers on the performance of T2 control chart. In addition, the performance of the non-robust and the proposed robust control charts is evaluated in Phase II.
Design/methodology/approach
In this paper some, robust approaches including weighted maximum likelihood estimation, redescending M-estimator and a combination of these two approaches (WRM) are used to decrease the effects of outliers on estimating the logistic regression parameters as well as the performance of the T2 control chart.
Findings
The results of the simulation studies in both Phases I and II show the better performance of the proposed robust control charts rather than the non-robust control chart for estimating the logistic regression profile parameters and monitoring the logistic regression profiles.
Practical implications
In many practical applications, there are outliers in processes which may affect the estimation of parameters in Phase I and as a result of deteriorate the statistical performance of control charts in Phase II. The methods developed in this paper are effective for decreasing the effect of outliers in both Phases I and II.
Originality/value
This paper considers monitoring the logistic regression profile in Phase I under the presence of outliers. Also, three robust approaches are developed to decrease the effects of outliers on the parameter estimation and monitoring the logistic regression profiles in both Phases I and II.
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High-growth firms (HGFs) make a considerable contribution to economic growth, and in recent years they have received increasing interest from entrepreneurship scholars. By…
Abstract
High-growth firms (HGFs) make a considerable contribution to economic growth, and in recent years they have received increasing interest from entrepreneurship scholars. By analysing recent findings in the literature of high-growth firms, this study identifies some Stylized Facts, as well as contradictory findings, and also some unknowns regarding the determinants and internal strategies of HGFs, particularly on the persistence of their superior growth performance and the implications of recent findings for economic policy.