title: In-kernel passive measurement of the performance impact of hidden terminals in 802.11 wireless networks

authors: Raynel, Scott McKenzie

subjects: computer science

abstract: The negative performance impact of the presence of hidden terminals in wireless networks has been well know for decades. Despite much research in the area, many deployed networks continue to suffer a performance penalty because of hidden terminals. Ad hoc wireless networks are particularly susceptible to hidden terminal collisions because there are fewer opportunities to plan the network in a way that avoids or reduces the number of hidden terminals. Measuring the presence of hidden terminals and the impact they are having on performance is difficult, especially in a network of many nodes. Without such measurements, the users and operators of wireless networks can not tell if performance problems are caused by hidden terminals or some other problem. We introduce new methodology that can detect the presence of hidden terminals and estimate the performance impact they are causing. The methodology requires no additional hardware and is suitable for wide scale deployment and long term operation. The approach is based on in-kernel instrumentation of the wireless network stack. The design, implementation, and testing of the approach are covered. Results from in-lab testing and the measurement of a live commercial 802.11 network are also presented, including a case study where performance was significantly improved.

text: In-kernel passive measurement of the performance impact of hidden terminals in 802.11 wireless networks The negative performance impact of the presence of hidden terminals in wireless networks has been well know for decades. Despite much research in the area, many deployed networks continue to suffer a performance penalty because of hidden terminals. Ad hoc wireless networks are particularly susceptible to hidden terminal collisions because there are fewer opportunities to plan the network in a way that avoids or reduces the number of hidden terminals. Measuring the presence of hidden terminals and the impact they are having on performance is difficult, especially in a network of many nodes. Without such measurements, the users and operators of wireless networks can not tell if performance problems are caused by hidden terminals or some other problem. We introduce new methodology that can detect the presence of hidden terminals and estimate the performance impact they are causing. The methodology requires no additional hardware and is suitable for wide scale deployment and long term operation. The approach is based on in-kernel instrumentation of the wireless network stack. The design, implementation, and testing of the approach are covered. Results from in-lab testing and the measurement of a live commercial 802.11 network are also presented, including a case study where performance was significantly improved.

year: 2011

title: A descriptive study exploring the potential benefits of a model train club community for children with developmental disabilities

authors: Geary, Tamara

subjects: Autistic people

abstract: Approximately 1 in 100 individuals in New Zealand are diagnosed with autism spectrum disorder (ASD), facing significant challenges in socialisation and communication. Identifying effective methods to enhance these skills is important, as difficulties can lead to adversity in independent living, employment, and relationships.
Research indicates that utilising items of interest can boost social interaction motivations in autistic individuals. For example, Le Goff’s study demonstrated how structured, interest-based activities like LEGO can promote social engagement.
Building on Le Goff’s (2004) findings, this study examined opportunities for facilitating social interactions and communication among autistic children through a model train club. A mixed-methods approach was applied, gathering data via observations, caregiver interviews, a volunteer focus group, and case studies. Observational data confirmed instances of social interaction and engagement with trains. Caregiver interviews revealed the club’s beneficial impact on their children and their reasons for ongoing involvement. The volunteer focus group expressed dedication to maintaining an inclusive and engaging atmosphere, emphasising the club's social value. Meanwhile, case studies showed that neurodivergent individuals participated in social interactions, joint attention, and engagement with trains within this environment. 
The findings indicate that the model train club is a valuable space for neurodivergent children, particularly those with milder autism, to practice and improve their social interaction skills in a supportive setting.

text: A descriptive study exploring the potential benefits of a model train club community for children with developmental disabilities Approximately 1 in 100 individuals in New Zealand are diagnosed with autism spectrum disorder (ASD), facing significant challenges in socialisation and communication. Identifying effective methods to enhance these skills is important, as difficulties can lead to adversity in independent living, employment, and relationships.
Research indicates that utilising items of interest can boost social interaction motivations in autistic individuals. For example, Le Goff’s study demonstrated how structured, interest-based activities like LEGO can promote social engagement.
Building on Le Goff’s (2004) findings, this study examined opportunities for facilitating social interactions and communication among autistic children through a model train club. A mixed-methods approach was applied, gathering data via observations, caregiver interviews, a volunteer focus group, and case studies. Observational data confirmed instances of social interaction and engagement with trains. Caregiver interviews revealed the club’s beneficial impact on their children and their reasons for ongoing involvement. The volunteer focus group expressed dedication to maintaining an inclusive and engaging atmosphere, emphasising the club's social value. Meanwhile, case studies showed that neurodivergent individuals participated in social interactions, joint attention, and engagement with trains within this environment. 
The findings indicate that the model train club is a valuable space for neurodivergent children, particularly those with milder autism, to practice and improve their social interaction skills in a supportive setting.

year: 2025-06-14

title: Composition Portfolio

authors: Ulenberg, Phillippa

subjects: composition portfolio

abstract: The music written for this portfolio offers creative answers to some of the challenges facing contemporary New Zealand composition, including multiculturalism.This has involved in-depth research using a variety of methods. Engagement was undertaken with linguists and musicians from Malaysia and Korea, who not only assisted with texts, but also spoke knowledgeably about their cultural traditions and past and present musical genres. The inclusion of Chinese gu-zheng in several of the works was made possible with the assistance given by Chen Xi Yao, an excellent performer who comes from a long lineage of musicians. Attending concerts given by performers of the instruments that have been used in the portfolio was essential to understanding the sounds and uses of the instruments. In addition, on-line sources include many examples of the sounds. Attendance at workshops on Māori taonga pūoro also brought the additional honour, benefits and experience of making and playing the instruments, and the opportunities to meet and work with leading makers and performers of these musical treasures. Sources of Western classical music that have been particularly influential during the writing of the portfolio are orchestral works by Igor Stravinsky, Samuel Barber and Param Vir, and the song cycles of Alban Berg and Benjamin Britten. Luciano Berio’s virtuosic piece for solo bassoon was also instructive. Experiences of composition, reflection and scholarly research underpin the portfolio and have have informed the composition of each work.

text: Composition Portfolio The music written for this portfolio offers creative answers to some of the challenges facing contemporary New Zealand composition, including multiculturalism.This has involved in-depth research using a variety of methods. Engagement was undertaken with linguists and musicians from Malaysia and Korea, who not only assisted with texts, but also spoke knowledgeably about their cultural traditions and past and present musical genres. The inclusion of Chinese gu-zheng in several of the works was made possible with the assistance given by Chen Xi Yao, an excellent performer who comes from a long lineage of musicians. Attending concerts given by performers of the instruments that have been used in the portfolio was essential to understanding the sounds and uses of the instruments. In addition, on-line sources include many examples of the sounds. Attendance at workshops on Māori taonga pūoro also brought the additional honour, benefits and experience of making and playing the instruments, and the opportunities to meet and work with leading makers and performers of these musical treasures. Sources of Western classical music that have been particularly influential during the writing of the portfolio are orchestral works by Igor Stravinsky, Samuel Barber and Param Vir, and the song cycles of Alban Berg and Benjamin Britten. Luciano Berio’s virtuosic piece for solo bassoon was also instructive. Experiences of composition, reflection and scholarly research underpin the portfolio and have have informed the composition of each work.

year: 2011