109 resultados para Box-Cox transformation and quintile-based capability indices

em Deakin Research Online - Australia


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Estimating the process capability index (PCI) for non-normal processes has been discussed by many researches. There are two basic approaches to estimating the PCI for non-normal processes. The first commonly used approach is to transform the non-normal data into normal data using transformation techniques and then use a conventional normal method to estimate the PCI for transformed data. This is a straightforward approach and is easy to deploy. The alternate approach is to use non-normal percentiles to calculate the PCI. The latter approach is not easy to implement and a deviation in estimating the distribution of the process may affect the efficacy of the estimated PCI. The aim of this paper is to estimate the PCI for non-normal processes using a transformation technique called root transformation. The efficacy of the proposed technique is assessed by conducting a simulation study using gamma, Weibull, and beta distributions. The root transformation technique is used to estimate the PCI for each set of simulated data. These results are then compared with the PCI obtained using exact percentiles and the Box-Cox method. Finally, a case study based on real-world data is presented.

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Several measures of process yield, defined on univariate and multivariate normal process characteristics, have been introduced and studied by several authors. These measures supplement several well-known Process Capacity Indices (PCI) used widely in assessing the quality of products before being released into the marketplace. In this paper, we generalise these yield indices to the location-scale family of distributions which includes the normal distribution as one of its member. One of the key contributions of this paper is to demonstrate that under appropriate conditions, these indices converge in distribution to a normal distribution. Several numerical examples will be used to illustrate our procedures and show how they can be applied to perform statistical inferences on process capability.

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When the distribution of a process characterized by a profile is non normal, process capability analysis using normal assumption often leads to erroneous interpretations of the process performance. Profile monitoring is a relatively new set of techniques in quality control that is used in situations where the state of product or process is represented by a function of two or more quality characteristics. Such profiles can be modeled using linear or nonlinear regression models. In some applications, it is assumed that the quality characteristics follow a normal distribution; however, in certain applications this assumption may fail to hold and may yield misleading results. In this article, we consider process capability analysis of non normal linear profiles. We investigate and compare five methods to estimate non normal process capability index (PCI) in profiles. In three of the methods, an estimation of the cumulative distribution function (cdf) of the process is required to analyze process capability in profiles. In order to estimate cdf of the process, we use a Burr XII distribution as well as empirical distributions. However, the resulted PCI with estimating cdf of the process is sometimes far from its true value. So, here we apply artificial neural network with supervised learning which allows the estimation of PCIs in profiles without the need to estimate cdf of the process. Box-Cox transformation technique is also developed to deal with non normal situations. Finally, a comparison study is performed through the simulation of Gamma, Weibull, Lognormal, Beta and student-t data.

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This article considers a comparison study between different non-normal process capability estimation methods and utilizing themin the leukocyte filtering process in blood service sectors. Since the amount of leukocyte in a unit of the blood is a critical issue inthe blood transfusion process and patient safety, estimating and monitoring the capability of the leukocyte filtering process to meetthe target window is very important for blood service sectors. However, observed data from the leukocyte filtering process showthat the leukocyte levels after filtering demonstrate a right skewed distribution and applying conventional methods with a normalityassumption fails to provide trustful results. Hence, we first conduct a simulation study to compare different methods in estimating theprocess capability index of non-normal processes and then we apply these techniques to obtain the process capability of the leukocytefiltering process. The study reveals that the Box-Cox transformation method provides reliable estimation of the process capability ofthe leukocyte filtering process.

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In response to the forces of globalisation, societies and organisations have had to adapt and even proactively transform themselves. Universities, as knowledge-based organisations, have recognised that there are now many other important sites of knowledge construction and use. The apparent monopoly over valued forms of knowledge making and knowledge certification is disappearing. Universities have had to recognise the value of practical working knowledge developed in workplace settings beyond university domains, and promote the value of academic forms of knowledge making to the practical concerns of everyday learning. It is within this broader systems view that professional curriculum development undertaken by universities needs to be examined.

University educational planning responds to these external forces in ways that are drawing together formal academic capability/competence and practice-based capability/competence. Both forms of academic and practice-based knowledge and knowing are being equally valued and related one to the other. University planning in turn gives impetus to the development of new forms of professional education curricula. This paper presents a contemporary case of a designed professional curriculum in the field of information technology that situates workplace learning as a central element in the education of Information Technology (IT)/Information Systems (IS) professionals.

The key dimensions of the learning environment of Deakin University’s BIT (Hons) program are considered with a view to identifying areas of strong integration between the worlds of academic and workplace learning from the perspectives of major stakeholders. The dynamic interplay between forms of theorising and practising is seen as critical in educating students for professional capability in their chosen field. From this analysis, an applied research agenda, relating to desired forms of professional learning in higher education, is outlined, with specific reference to the information and communication technology professions.

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Why are beginning teachers leaving the profession in large numbers? Are they leaving because of their dissatisfaction with teaching? Are they leaving because of the conditions of their work that shape their identity? Teacher identity work emphasises it is important beginning teachers understand their professional identity as something shifting, fluid and emerging – not fixed. These and other water metaphors – such as ‘washout’, ‘sink or swim’, and ‘thrown in the deep end’ – are often used to describe beginning teachers’ experiences. Such words and metaphors assist to portray the fluid and unpredictable nature of identity transformation. However, these survival terms also influence beginning teachers to believe that their transition to teaching will be difficult. Recently there has been an increased concern over beginning teacher attrition linked to the difficulties they encounter in their early years of teaching. Yet the conditions of beginning teachers’ work in Victorian schools in Australia – including the contractual nature of employment of first year (1yr) teachers – encourage these 1yr practitioners to view their work as semi-permanent. As a result these 1yr teachers do not see themselves as teaching for extended periods of time, as was once the case. Throughout 2011 twelve 1yr teachers shared their experiences of identity transformation in semi-structured interviews with the researcher. Their interview data was analysed through a theatre-based research method, examining how first experiences shape teachers’ future practice and identity. This presentation includes excerpts from the theatre-based research performance ‘The First Time’, and expands on the methodological approaches taken to analyse the data in a way that reflects the fluid and unpredictable nature of teachers’ identity formation and transformation. This qualitative study allows categories of description to emerge from the data rather than pre-determining categories of investigation. As such the processes of scripting, rehearsing, and performing, were utilised to analyse and re-present the data. In an aim to uncover questions that have been buried by answers, the research is oriented as a phenomenographic inquiry. This mode of inquiry seeks to describe, analyse, and understand the qualitatively different experiences 1yr teachers undergo in their identity formation and transformation. The results of this research reveal that beginning teachers’ identity transformation through their first experiences have both individual features specific to each teacher’s roles and aspirations, and extra-individual factors such as interactions, affiliations, and status, which shape their identity. Categories of description that have emerged from the analysis include survival, liminal, and hegemonic discourses, artifacts as symbols of belonging, and the impact of the contractual nature of teaching. Implications of this research focus on the importance for beginning teachers to develop an understanding of the transformative nature of identity in relation to the practice of teaching, to counter the negative preconceptions beginning teachers are told to expect as rites of passage upon entering the profession. The research outcomes have implications for teacher educators and in-service teachers negotiating the waters of an ever-changing profession.

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Understanding neural functions requires knowledge from analysing electrophysiological data. The process of assigning spikes of a multichannel signal into clusters, called spike sorting, is one of the important problems in such analysis. There have been various automated spike sorting techniques with both advantages and disadvantages regarding accuracy and computational costs. Therefore, developing spike sorting methods that are highly accurate and computationally inexpensive is always a challenge in the biomedical engineering practice.

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Purpose: In profile monitoring, which is a growing research area in the field of statistical process control, the relationship between response and explanatory variables is monitored over time. The purpose of this paper is to focus on the process capability analysis of linear profiles. Process capability indices give a quick indication of the capability of a manufacturing process. Design/methodology/approach: In this paper, the proportion of the non-conformance criteria is employed to estimate process capability index. The paper has considered the cases where specification limits is constant or is a function of explanatory variable X. Moreover, cases where both equal and random design schemes in profile data acquisition is required (as the explanatory variable) is considered. Profiles with the assumption of deterministic design points are usually used in the calibration applications. However, there are other applications where design points within a profile would be i.i.d. random variables from a given distribution. Findings: Simulation studies using simple linear profile processes for both fixed and random explanatory variable with constant and functional specification limits are considered to assess the efficacy of the proposed method. Originality/value: There are many cases in industries such as semiconductor industries where quality characteristics are in form of profiles. There is no method in the literature to analyze process capability for theses processes, however recently quite a few methods have been presented in monitoring profiles. Proposed methods provide a framework for quality engineers and production engineers to evaluate and analyze capability of the profile processes. © Emerald Group Publishing Limited.

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Australia's box-ironbark forests and woodlands once covered about 14 per cent of the State of Victoria on the riverine plains and foothills of the Great Dividing Range. But approximately 83 per cent of the total original habitat has been destroyed and what remains of this significant ecosystem is now highly fragmented and vulnerable to further degradation. Moreover, only 14 per cent of the area remaining is on public land. A 10 year campaign on the part of the environmental movement eventually succeeded in forcing the State government to conduct an independent inquiry into this ecosystem and make recommendations on future management. This paper outlines the innovative public participation process adopted by the Victorian State government and the outcomes of the inquiry. A subsequent compensation package for commercial operations disadvantaged by the proclamation of a series of new national parks is also discussed, as are the shortcomings of a process that can have little or no impact on what happens on private land.

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OBJECTIVES: The National Benchmarks and Evidence-Based National Clinical Guidelines for Heart Failure Management Programs Study is a national, multicenter study designed to determine the nature, range, and effect of interventions applied by chronic heart failure management programs (CHF-MPs) throughout Australia on patient outcomes. Its primary objective is to use these data to develop national benchmarks and evidence-based clinical guidelines and optimize their cost-effective application by reducing quality and outcome variability. DATA SOURCES/STUDY SETTING: Primary data will be collected from CHF-MP coordinators and CHF patients enrolled in these programs on a national basis. Secondary outcome data will be collected from a national morbidity record and from patients' medical records. STUDY DESIGN: Stage I of the study involves a prospective clinical audit of all CHF-MPs throughout Australia (n = 45) to determine the extent of variability in programs currently. Stage II is a prospective cross-sectional survey design enrolling 1,500 patients (average of 40 patients per program) to firstly determine the typical profile of patients being managed via a CHF-MP in Australia and, secondly, the subsequent morbidity and mortality during the 6-month follow-up. Outcome data will be subject to multivariate analysis to determine the key components of care in this regard. All study data will be then examined in the final stage of the study (III) to develop national benchmarks for the application and auditing of CHF-MPs in Australia. CONCLUSION: Variability in patient outcomes is a product of heterogeneity among CHF-MPs. The development of national benchmarks will minimize such heterogeneity and will provide a greater level of evidence for their cost-effective application.

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‘Good governance’ is increasingly regarded as pivotal to development in developing countries. The six indicators recognized as the most effective measurement tools of ‘good governance’ across the world are: voice and accountability; political stability and absence of violence; government effectiveness; regulatory quality; rule of law and control of corruption (Kaufmann, Kraay and Lobaton, 2003: 8–9). This paper investigates how lack of ‘good governance’ affects the success and sustainability of the market-based reforms undertaken in the agriculture sector of Bangladesh. The reforms have been associated with increased food grain production, improved food security conditions and easy access by farmers to agricultural inputs. However, a significant problem has arisen recently: the sale of low quality and underweight agricultural inputs sometimes at higher prices has become common. Not only is this problem undermining the positive impact of the reforms, it is also threatening their sustainability. The paper argues that the problems with regulatory quality, rule of law and control of corruption – indicators of good governance – are the underlying reasons for this problem. In the context of increasing pressures from donors to pursue market-based reforms, this paper stresses the need for integrated governance linking government, business and civil society as paramount for promoting good governance for the success and sustainability of the reforms.

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The objective of this study was to determine the feasibility and acceptability of a referral and outcall programme from a telephone-based information and support service, for men newly diagnosed with colorectal or prostate cancer. A block randomized controlled trial was performed involving 100 newly diagnosed colorectal and prostate cancer patients. Patients were referred to the Cancer Information Support Service (CISS) through clinicians at diagnosis. Clinicians were randomized into one of three conditions. Active referral 1: specialist referral with four CISS outcalls: (1) ≤1 week of diagnosis; (2) at 6 weeks; (3) 3 months; and (4) 6 months post diagnosis. Active referral 2: specialist referral with one CISS outcall ≤1 week of diagnosis. Passive referral: specialist recommended patient contacts CISS, but contact at the patient's initiative. Patients completed research questionnaires at study entry (before CISS contact), then 4 and 7 months post diagnosis. Overall, 96% of participants reported a positive experience with the referral process; 87% reported they were not concerned about receiving the calls; and 84% indicated the timing of the calls was helpful. In conclusion, the referral and outcall programme was achievable and acceptable for men newly diagnosed with colorectal or prostate cancer.

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This paper proposes a hyperlink-based web page similarity measurement and two matrix-based hierarchical web page clustering algorithms. The web page similarity measurement incorporates hyperlink transitivity and page importance within the concerned web page space. One clustering algorithm takes cluster overlapping into account, another one does not. These algorithxms do not require predefined similarity thresholds for clustering, and are independent of the page order. The primary evaluations show the effectiveness of the proposed algorithms in clustering improvement.