Costing Mixed Coxian Phase-type Systems with Poisson Arrivals

Previously, we developed a modeling framework which classifies individuals with respect to their length of stay (LOS) in the transient states of a continuous-time Markov model with a single absorbing state; phase-type models are used for each class of the Markov model. We here add costs and obtain results for moments of total costs in (0, t], for an individual, a cohort arriving at time zero and when arrivals are Poisson. Based on stroke patient data from the Belfast City Hospital we use the overall modelling framework to obtain results for total cost in a given time interval.     

The impact of the Victorian infringements system on disadvantaged groups: findings from a qualitative study

This article focuses on the infringements system currently operating in the state of Victoria, Australia and, in particular, its impact on disadvantaged groups, such as people suffering homelessness, drug and alcohol dependency, mental illness, acquired brain injury, poverty, and domestic violence. The concerns of lawyers working in community legal centres striving to address the needs of people in these disadvantaged groups prompted this qualitative study, which involved in‐depth interviews with key stakeholders in the infringements system. Participants included those who issue and enforce fines, those who represent vulnerable fine recipients, and the fine recipients themselves. The research sought participants' understanding of the system, its aims, and its outcomes. This article presents an overview of the research findings in relation to the complex Victorian infringements system process, net‐widening, proportionality, and the 'special circumstances' process. Our findings suggest that the Victorian infringements system is expedient and efficient when people can promptly pay their fines. However, multiple issues need to be addressed if the system is to be just and fair to people suffering various types of disadvantage. A number of systemic changes and educational initiatives are recommended, along with law reform that addresses the unreasonable and unacceptable impacts on disadvantaged groups in Victoria.     

Education and employment opportunities among staff in Aboriginal family service agencies

The purpose of the study was to describe ways that successful culture‐based Aboriginal preventive family service agencies offer employment and education opportunities for staff. Staff in three inner‐city, culture‐based Aboriginal family agencies were asked about their employment and educational opportunities. Forty‐four individuals were asked the question: ‘what employment and education opportunities have you had while in this job?’ A total of 81 unique responses were received. Participants grouped the responses into eight themes including: planning for services, promotion within the agency, specific skill development, enhanced self‐confidence, cultural awareness, teaching others, workshops as well as certified training. Differences between the experiences of study participants and the existing literature indicate that practices within culture‐based Aboriginal family agencies are distinct in relation to funding, staff mobility, strengths‐base, practical training and cultural knowledge, and that these should be understood and recognized formally in funding decisions and in future research.     

Physical needs of Aboriginal foster parents

Aboriginal foster parents were surveyed about their physical needs. Each was asked ‘What do you need physically to be a good foster parent?’ A total of 39 unique responses were made. They were grouped together by participants and the grouping data were analysed using multidimensional scaling and cluster analysis. Five concepts resulted from the analysis. The concepts included physical, financial and emotional resources, supplies and equipment, community, fitness and wellness. Results were compared and contrasted with the fostering literature.     

Emotional needs of Aboriginal foster parents

Aboriginal children are overrepresented in care. Aboriginal foster parents are underrepresented. There is a need to recruit and retain Aboriginal foster parents. In the study, Aboriginal foster parents were asked: “What do you need emotionally to be a good foster parent?” The results were analyzed using multidimensional scaling and cluster analysis, leading to eight concepts, including: awareness, contentment, self‐assurance, appreciation, resolve, space, caring, and commitment to one's values. These results were compared with the existing foster parent literature. Similarities and differences were described.     

Forecasting before,during, and after recession with singular spectrum analysis

The aim of this research is to apply the singular spectrum analysis (SSA) technique, which is a relatively new and powerful technique in time series analysis and forecasting, to forecast the 2008 UK recession, using eight economic time series. These time series were selected as they represent the most important economic indicators in the UK. The ability to understand the underlying structure of these series and to quickly identify turning points such as the on-set of the recent recession is of key interest to users. In recent years, the SSA technique has been further developed and applied to many practical problems. Hence, these series will provide an ideal practical test of the potential benefits from SSA during one of the most challenging periods for econometric analyses of recent years. The results are compared with those obtained using the ARIMA and Holt–Winters models as these methods are currently used as standard forecasting methods in the Office for National Statistics in the UK.     

An Extended Mixture Distribution Survival Tree for Patient Pathway Prognostication

Mixture distribution survival trees are constructed by approximating different nodes in the tree by distinct types of mixture distributions to improve within node homogeneity. Previously, we proposed a mixture distribution survival tree-based method for determining clinically meaningful patient groups from a given dataset of patients’ length of stay. This article extends this approach to examine the interrelationship between length of stay in hospital, outcome measures, and other covariates. We describe an application of this approach to patient pathway and examine the relationship between length of stay in hospital and/or treatment outcome using five-years’ retrospective data of stroke patients.     

Improved best linear unbiased estimators for the simple linear regression model using double ranked set sampling schemes

ABSTRACT

In this paper, we consider the best linear unbiased estimators (BLUEs) based on double ranked set sampling (DRSS) and ordered DRSS (ODRSS) schemes for the simple linear regression model with replicated observations. We assume three symmetric distributions for the random error term, i.e., normal, Laplace and some scale contaminated normal distributions. The proposed BLUEs under DRSS (BLUEs-DRSS) and ODRSS (BLUEs-ODRSS) are compared with the BLUEs based on ordered simple random sampling (OSRS), ranked set sampling (RSS), and ordered RSS (ORSS) schemes. These estimators are compared in terms of relative efficiency (RE), RE of determinant (RED), and RE of trace (RET). It is found that the BLUEs-ODRSS are uniformly better than the BLUEs based on OSRS, RSS, ORSS, and DRSS schemes. We also compare the estimators based on imperfect RSS (IRSS) schemes. It is worth mentioning here that the BLUEs under ordered imperfect DRSS (OIDRSS) are better than their counterparts based on IRSS, ordered IRSS (OIRSS), and imperfect DRSS (IDRSS) methods. Moreover, for sensitivity analysis of the BLUEs, we calculate REs and REDs of the BLUEs under the assumption of normality when in fact the parent distribution follows a non normal symmetric distribution. It turns out that even under violation of normality assumptions, BLUEs of the intercept and the slope parameters are found to be unbiased with equal REs under each sampling scheme. It is also observed that the BLUEs under ODRSS are more efficient than the existing BLUEs.