title: Racing committees for large datasets

authors: Frank, Eibe

subjects: Machine learning

abstract: This paper proposes a method for generating classifiers from large datasets by building a committee of simple base classifiers using a standard boosting algorithm.  It allows the processing of large datasets even if the underlying base learning algorithm cannot efficiently do so.  The basic idea is to split incoming data into chunks and build a committee based on classifiers build from these individual chunks [3].  Our method extends earlier work in two ways:  (a) the best chunk size is chosen automatically by racing committees corresponding to different chunk sizes, and (b) the committees are pruned adaptively to keep the size of each individual committee as small as possible without negatively affecting accuracy.  This paper shows that choosing an appropriate chunk size automatically is important because the accuracy of the resulting committee can vary significantly with the chunk size.  It also shows that pruning is crucial to make the method practical for large datasets in terms of running time and memory requirements.  Surprisingly, the results demonstrate that pruning can also improve accuracy.

text: Racing committees for large datasets This paper proposes a method for generating classifiers from large datasets by building a committee of simple base classifiers using a standard boosting algorithm.  It allows the processing of large datasets even if the underlying base learning algorithm cannot efficiently do so.  The basic idea is to split incoming data into chunks and build a committee based on classifiers build from these individual chunks [3].  Our method extends earlier work in two ways:  (a) the best chunk size is chosen automatically by racing committees corresponding to different chunk sizes, and (b) the committees are pruned adaptively to keep the size of each individual committee as small as possible without negatively affecting accuracy.  This paper shows that choosing an appropriate chunk size automatically is important because the accuracy of the resulting committee can vary significantly with the chunk size.  It also shows that pruning is crucial to make the method practical for large datasets in terms of running time and memory requirements.  Surprisingly, the results demonstrate that pruning can also improve accuracy.

year: 2002-06-01

title: Social Competence and Executive Functioning in Adolescents Following a Mild Traumatic Brain Injury

authors: Hollands, David M.

subjects: mild traumatic brain injury

abstract: A traumatic brain injury (TBI) is one of the most common injuries sustained by adolescents and a leading cause of death and long-term disability. The vast majority of these cases are mild and yet they can cause a range of difficulties across multiple domains which can negatively impact upon a person’s social functioning. The aim of this study was to determine whether adolescents who have sustained a mild TBI would differ from their uninjured peers in regards to social competence. A secondary aim was to investigate whether there was a relationship between an adolescent’s level of social competence and their executive functioning abilities. 
This investigation involved a population-based sample of 30 young adolescents who had sustained a mild TBI between the age of 12 and 15 years. Parental and/or self-report ratings of behaviour and executive function, as well as a performance-based measure of cognition were explored at 12 months post-injury. These adolescents were then compared to a community recruited, age-matched sample of their TBI-free peers. 
A composite scale of social competence based on observable behaviours was formulated. The results showed adolescents with a mild TBI demonstrated greater difficulties with socially competent behaviours compared to their uninjured peers. These difficulties were found to centre around aspect of their behavioural functioning, particularly regarding their regulation and inhibition of behaviour. Higher levels of dysfunction in the mild TBI sample were also found for parental ratings of behaviours associated with executive functions. A relationship between the Social Competence Index and executive function was not found. However, a relationship between the Social Competence Index and composite measures of cognitive functioning was. Suggesting there are more cognitions behind socially competent behaviour than the domain of executive functions alone. These findings highlight the need for post-injury screening for behavioural and social difficulties, with interventions implemented as required, to reduce the risk of on-going social impairment.

text: Social Competence and Executive Functioning in Adolescents Following a Mild Traumatic Brain Injury A traumatic brain injury (TBI) is one of the most common injuries sustained by adolescents and a leading cause of death and long-term disability. The vast majority of these cases are mild and yet they can cause a range of difficulties across multiple domains which can negatively impact upon a person’s social functioning. The aim of this study was to determine whether adolescents who have sustained a mild TBI would differ from their uninjured peers in regards to social competence. A secondary aim was to investigate whether there was a relationship between an adolescent’s level of social competence and their executive functioning abilities. 
This investigation involved a population-based sample of 30 young adolescents who had sustained a mild TBI between the age of 12 and 15 years. Parental and/or self-report ratings of behaviour and executive function, as well as a performance-based measure of cognition were explored at 12 months post-injury. These adolescents were then compared to a community recruited, age-matched sample of their TBI-free peers. 
A composite scale of social competence based on observable behaviours was formulated. The results showed adolescents with a mild TBI demonstrated greater difficulties with socially competent behaviours compared to their uninjured peers. These difficulties were found to centre around aspect of their behavioural functioning, particularly regarding their regulation and inhibition of behaviour. Higher levels of dysfunction in the mild TBI sample were also found for parental ratings of behaviours associated with executive functions. A relationship between the Social Competence Index and executive function was not found. However, a relationship between the Social Competence Index and composite measures of cognitive functioning was. Suggesting there are more cognitions behind socially competent behaviour than the domain of executive functions alone. These findings highlight the need for post-injury screening for behavioural and social difficulties, with interventions implemented as required, to reduce the risk of on-going social impairment.

year: 2014

title: Weaving the realities and responsibilities: Crossing culture and concepts of healing within co-existing mental health and addictive disorders.

authors: McLachlan, Andre David

subjects: Maori

abstract: Within ‘Mainstream’ western and Kaupapa Māori services, competing priorities often mean that cultural and clinical services are not implemented in unison. Without this ‘unison’, treatment of Māori with co-existing mental health and addictive disorders may be ineffective. This paper reflects the journey of a small social service agency ‘Pai Ake Solutions Limited’ (PASL) in integrating western clinical approaches within tikanga Māori values. 
Pai Ake Solutions Limited (PASL) provides a range of group and individual services to whānau who are affected by mental illness and co-existing substance use problems. The initial development of the service was based on the whakaaro of providing ‘pai ake’ (better) services for whānau in the greater Waikato. These services were initially founded on the strong values of founders Mihaka Hohua and the late Ritchie Re Cribb, which were influenced by the practices and experiences of Ngati Kahangungu, Ngati Haua, and Waikato-Maniopoto. From an initial non-clinical service provision contract, PASL began receiving referrals from individuals and whānau whose needs were not being met by mainstream service providers. Encouraging outcomes and an internal agency review of clientele utilising the service, identified that those accessing PASL services were experiencing socially and clinically significant mental and physical health, addiction and psychosocial problems.

text: Weaving the realities and responsibilities: Crossing culture and concepts of healing within co-existing mental health and addictive disorders. Within ‘Mainstream’ western and Kaupapa Māori services, competing priorities often mean that cultural and clinical services are not implemented in unison. Without this ‘unison’, treatment of Māori with co-existing mental health and addictive disorders may be ineffective. This paper reflects the journey of a small social service agency ‘Pai Ake Solutions Limited’ (PASL) in integrating western clinical approaches within tikanga Māori values. 
Pai Ake Solutions Limited (PASL) provides a range of group and individual services to whānau who are affected by mental illness and co-existing substance use problems. The initial development of the service was based on the whakaaro of providing ‘pai ake’ (better) services for whānau in the greater Waikato. These services were initially founded on the strong values of founders Mihaka Hohua and the late Ritchie Re Cribb, which were influenced by the practices and experiences of Ngati Kahangungu, Ngati Haua, and Waikato-Maniopoto. From an initial non-clinical service provision contract, PASL began receiving referrals from individuals and whānau whose needs were not being met by mainstream service providers. Encouraging outcomes and an internal agency review of clientele utilising the service, identified that those accessing PASL services were experiencing socially and clinically significant mental and physical health, addiction and psychosocial problems.

year: 2008