title: Comparing classical criteria for selecting intra-class correlated features in Multimix

authors: Hunt, Lynette Anne

subjects: Science & Technology

abstract: The mixture approach to clustering requires the user to specify both the number of components to be fitted to the model and the form of the component distributions. In the Multimix class of models, the user also has to decide on the correlation structure to be introduced into the model. The behaviour of some commonly used model selection criteria is investigated when using the finite mixture model to cluster data containing mixed categorical and continuous attributes. The performance of these criteria in selecting both the number of components in the model and the form of the correlation structure amongst the attributes when fitting the Multimix class of models is illustrated using simulated data and a real medical data set. It is found that criteria based on the integrated classification likelihood have the best performance in detecting the number of clusters to be fitted to the model and in selecting the form of the component distributions. The performance of the Bayesian information criterion in detecting the correct model depends on the partitioning structure among the attributes while the Akaike information criterion and classification likelihood criterion perform in a less satisfactory way.

text: Comparing classical criteria for selecting intra-class correlated features in Multimix The mixture approach to clustering requires the user to specify both the number of components to be fitted to the model and the form of the component distributions. In the Multimix class of models, the user also has to decide on the correlation structure to be introduced into the model. The behaviour of some commonly used model selection criteria is investigated when using the finite mixture model to cluster data containing mixed categorical and continuous attributes. The performance of these criteria in selecting both the number of components in the model and the form of the correlation structure amongst the attributes when fitting the Multimix class of models is illustrated using simulated data and a real medical data set. It is found that criteria based on the integrated classification likelihood have the best performance in detecting the number of clusters to be fitted to the model and in selecting the form of the component distributions. The performance of the Bayesian information criterion in detecting the correct model depends on the partitioning structure among the attributes while the Akaike information criterion and classification likelihood criterion perform in a less satisfactory way.

year: 2016

title: Population trends, convictions and imprisonment: Demographic divergence, dichotomy and diversity

authors: Pool, Ian

subjects: convictions

abstract: The links between population patterns and trends, and policy and planning for the justice system is important. The trends in the number of convictions and imprisonments by regional councils are investigated for the period 1986 to 2001. This does not just focus on Custodial sentences but also looks at other types of sentences such as monetary and community sentences. Additionally, a regional estimate of the muster in prison is derived to give “normal” place of residence of those in prison. The relationship of imprisonment to other factors such as income, unemployment, sickness/invalid benefit rates, labour force participation rates and ethnicity is investigated. Some policy implications of these findings are presented.

text: Population trends, convictions and imprisonment: Demographic divergence, dichotomy and diversity The links between population patterns and trends, and policy and planning for the justice system is important. The trends in the number of convictions and imprisonments by regional councils are investigated for the period 1986 to 2001. This does not just focus on Custodial sentences but also looks at other types of sentences such as monetary and community sentences. Additionally, a regional estimate of the muster in prison is derived to give “normal” place of residence of those in prison. The relationship of imprisonment to other factors such as income, unemployment, sickness/invalid benefit rates, labour force participation rates and ethnicity is investigated. Some policy implications of these findings are presented.

year: 2006-02

title: Voices of the land: Richard Nunns in conversation with Martin Lodge

authors: Nunns, Richard

abstract: Richard Nunns in conversation with Martin Lodge

text: Voices of the land: Richard Nunns in conversation with Martin Lodge Richard Nunns in conversation with Martin Lodge

year: 2008