title: Compressing GPS data on mobile devices

authors: Lever, Ryan

subjects: computer science

abstract: In context-aware mobile systems, data on past user behaviour or use of a device can give critical information. The scale of this data may be large, and it must be quickly searched and retrieved. Compression is a powerful tool for both storing and indexing data. For text documents powerful algorithms using structured storage achieve high compression and rapid search and retrieval. Byte-stream techniques provide higher compression, but lack indexation and have slow retrieval. 
Location is a common form of context frequently used in research prototypes of tourist guide systems, location-aware searching and adaptive hypermedia. In this paper, we present an exploration of record-based compression of Global Positioning System (GPS) data that reveals significant technical limitations on what can be achieved on mobile devices, and a discussion of the benefits of different compression techniques on GPS data.

text: Compressing GPS data on mobile devices In context-aware mobile systems, data on past user behaviour or use of a device can give critical information. The scale of this data may be large, and it must be quickly searched and retrieved. Compression is a powerful tool for both storing and indexing data. For text documents powerful algorithms using structured storage achieve high compression and rapid search and retrieval. Byte-stream techniques provide higher compression, but lack indexation and have slow retrieval. 
Location is a common form of context frequently used in research prototypes of tourist guide systems, location-aware searching and adaptive hypermedia. In this paper, we present an exploration of record-based compression of Global Positioning System (GPS) data that reveals significant technical limitations on what can be achieved on mobile devices, and a discussion of the benefits of different compression techniques on GPS data.

year: 2006

title: Chemical Characterisation of Compression Wood in Plantation Grown Pinus Radiata

authors: Nanayakkara, Bernadette

subjects: Chemistry

abstract: The primary objective of this study was to find out if changes in chemistry could be used to quantify Pinus radiata compression wood severity or degree of compression wood development. Basic chemical composition and the lignin structure was assessed for a range of different compression wood samples sourced from juvenile wood, mature wood, earlywood, latewood, branches, knots, 2-year and 1-year old Pinus radiata. Fluorescence microscopy was used as the reference method to assess the degree of compression wood development. Lignin structure of compression wood was studied by thioacidolysis, size exclusion chromatography, and thioacidolysis/31P NMR spectroscopy.
Variation in the basic chemical composition and lignin structure with compression wood severity was ascertained. Results showed that, as the severity of compression wood changed, progressively from normal through mild to severe, all chemical parameters commonly associated with compression wood changed concurrently. With increasing severity lignin and galactose levels increased while glucose and mannose levels decreased.
Lignin structural changes were also associated with changing severity of compression wood. Levels of p-hydroxyphenyl (H) releasable β-ethers increased and guaiacyl (G) releasable β-ethers decreased. Similarly, levels of uncondensed p-hydroxyphenyl units increased, while uncondensed guaiacyl units decreased. Similar proportions of condensed guaiacyl units were present in compression wood and normal wood. Similar trends in chemical composition were observed between the compression wood and related opposite wood in branches, knots and young wood of Pinus radiata.
A number of chemical parameters changed linearly with compression wood severity. They were: the amount of lignin and galactose, the galactose/glucose ratio and p-hydroxyphenyl content in lignin. Parameters based on the p-hydroxyphenyl unit content in lignin, the H/G releasable β-ether ratio, releasable p-hydroxyphenyl β-ether units and uncondensed p-hydroxyphenyl C9 units are most suitable indicators of compression wood severity as they spanned a larger range relative to the normal wood levels and were not influenced by the morphological origin of wood samples. Chemical methods for quantifying compression wood severity should focus on the detection and measurement of these parameters.
Galactan present in Pinus radiata compression wood was isolated and characterised. Structural investigation by methylation analysis and NMR spectroscopy revealed that this galactan was largely composed of (1→4)-linked β-D-galactopyranose residues. No evidence was found to indicate the presence of any branches.
Characterisation of lignin in cell wall fractions of Pinus radiata normal wood revealed that middle lamella lignin has a higher lignin content, a lower amount of releasable β-ethers and a more condensed lignin than the secondary wall lignin. Levels of releasable p-hydroxyphenyl units were not higher in middle lamella lignin.
A new method based on thioacidolysis and 31P quantitative NMR spectroscopy for estimation of the degree of lignin condensation of the phenolic and etherified C9 units in in situ wood lignin is described. Using this method it was found that phenolic C9 units in in situ lignin were considerably less condensed than etherified C9 units in both compression wood and normal wood.

text: Chemical Characterisation of Compression Wood in Plantation Grown Pinus Radiata The primary objective of this study was to find out if changes in chemistry could be used to quantify Pinus radiata compression wood severity or degree of compression wood development. Basic chemical composition and the lignin structure was assessed for a range of different compression wood samples sourced from juvenile wood, mature wood, earlywood, latewood, branches, knots, 2-year and 1-year old Pinus radiata. Fluorescence microscopy was used as the reference method to assess the degree of compression wood development. Lignin structure of compression wood was studied by thioacidolysis, size exclusion chromatography, and thioacidolysis/31P NMR spectroscopy.
Variation in the basic chemical composition and lignin structure with compression wood severity was ascertained. Results showed that, as the severity of compression wood changed, progressively from normal through mild to severe, all chemical parameters commonly associated with compression wood changed concurrently. With increasing severity lignin and galactose levels increased while glucose and mannose levels decreased.
Lignin structural changes were also associated with changing severity of compression wood. Levels of p-hydroxyphenyl (H) releasable β-ethers increased and guaiacyl (G) releasable β-ethers decreased. Similarly, levels of uncondensed p-hydroxyphenyl units increased, while uncondensed guaiacyl units decreased. Similar proportions of condensed guaiacyl units were present in compression wood and normal wood. Similar trends in chemical composition were observed between the compression wood and related opposite wood in branches, knots and young wood of Pinus radiata.
A number of chemical parameters changed linearly with compression wood severity. They were: the amount of lignin and galactose, the galactose/glucose ratio and p-hydroxyphenyl content in lignin. Parameters based on the p-hydroxyphenyl unit content in lignin, the H/G releasable β-ether ratio, releasable p-hydroxyphenyl β-ether units and uncondensed p-hydroxyphenyl C9 units are most suitable indicators of compression wood severity as they spanned a larger range relative to the normal wood levels and were not influenced by the morphological origin of wood samples. Chemical methods for quantifying compression wood severity should focus on the detection and measurement of these parameters.
Galactan present in Pinus radiata compression wood was isolated and characterised. Structural investigation by methylation analysis and NMR spectroscopy revealed that this galactan was largely composed of (1→4)-linked β-D-galactopyranose residues. No evidence was found to indicate the presence of any branches.
Characterisation of lignin in cell wall fractions of Pinus radiata normal wood revealed that middle lamella lignin has a higher lignin content, a lower amount of releasable β-ethers and a more condensed lignin than the secondary wall lignin. Levels of releasable p-hydroxyphenyl units were not higher in middle lamella lignin.
A new method based on thioacidolysis and 31P quantitative NMR spectroscopy for estimation of the degree of lignin condensation of the phenolic and etherified C9 units in in situ wood lignin is described. Using this method it was found that phenolic C9 units in in situ lignin were considerably less condensed than etherified C9 units in both compression wood and normal wood.

year: 2007

title: Making the invisible visible: Exploring the complex pathways between childhood experiences of maltreatment and the perpetration of family harm

authors: Dempster-Rivett, Kirsty

subjects: Childhood maltreatment

abstract: Preventing family harm and providing care for those affected is a high priority for governments and social services worldwide. Adverse consequences of family harm continue to place demands on justice, mental health and care and protection services. The costs to individuals, families and communities are beyond measure, given that rates of family harm are under-reported. Quantitative researchers have demonstrated a link between childhood maltreatment and family harm perpetration with existing psychological theories used to explain this link. However, mainstream theories were first developed many decades ago, at a time when the notion of gender was not inclusively factored into theory development. Neither were they developed with or by Indigenous peoples, calling into question the translatability of mainstream theories for stopping the intergenerational transmission of trauma and violence. 
The main aim of this thesis was to explore the relationship between childhood maltreatment and the perpetration of family harm by investigating two research questions. How could psychological theories better explain the pathways between childhood experiences of maltreatment and family harm perpetration? And, to what extent do psychological theories about the cycle of family harm reflect the experiences of Māori and non-Māori men and women in Aotearoa New Zealand? To answer these questions, interviews were conducted with 16 individuals who self-identified as perpetrating family harm and had childhood histories of maltreatment. (n=8 men, n=8 women). Purposive sampling ensured an equal number of Māori (Indigenous people of Aotearoa New Zealand) and non-Māori participated in the research. Thematic analysis was utilised to examine the personal conceptualisations regarding the association between experiences of childhood maltreatment and subsequent perpetration of family harm. The core corpus of data explored the maltreatment-family harm relationship within and between Māori and non-Māori men and women. This thesis is comprised of three studies that investigate the intergenerational transmission of trauma and violence.

The first study analysed the interviews of the seven participants removed from their families of origin as children. All described ongoing experiences of poly-victimisation in subsequent placements, whether through adoption, foster or residential settings. When examined alongside all women interviewed in this thesis, men more often reported that their childhood maltreatment was overlooked by professionals. The findings of this study highlighted a relationship between the perpetration of family harm and limited relational and emotional experiences during childhood. Intervention points across the life span were identified to stop the intergenerational transmission of trauma and violence for people removed from their family of origin as children.

The second study focused on the experiences of the eight Māori men and women interviewed. A culture of silence surrounding childhood maltreatment pervaded all interviewees’ childhood experiences. However, additional issues, including cultural isolation, were evident for Māori from the adults and professionals charged with their care. Māori interviewees identified three core Indigenous concepts that facilitated healing and intergenerational wellbeing: Wairua (spiritual connection), Pou (becoming a symbol of strength and support for self and others), and Tūrangawaewae (finding a sense of belonging). A return to Indigenous knowledge and practices was integral to stopping the intergenerational transmission of trauma and violence. This highlights the importance of privileging Indigenous knowledge in existing theoretical understanding of the cycle of family harm and incorporation in prevention initiatives.

The final study explored the impact of psychological distress within the cycle of family harm. Everyone interviewed experienced severe adverse trauma reactions linked to mental health and addiction issues, self-harm and suicidality, and instances of family harm. A significant barrier to psychological and familial wellbeing was the lack of access to integrated models of care capable of responding to complex and intertwined issues in trauma informed and Indigenous informed ways. Thus, family harm, trauma and mental health and addiction services need to work together to tailor and deliver treatment according to the individual and family needs to break the cycle of family harm and ongoing adverse life course trajectories. 

This research identifies significant limitations in the psychological theories that usually contribute to thinking about family harm. There has been a particular failure to develop a theory that accounts for the heterogeneous cultural and gendered experiences of the cycle of family harm. Going forward, expanding the? view of traditional psychological theories of intergenerational trauma and violence is required to account for the historical trauma of colonisation and the ongoing adverse consequences for Indigenous communities. Family harm prevention initiatives must be led by and/or developed in partnership with and by Indigenous peoples to ensure responsivity through active incorporation of traditional practices for intergenerational healing and wellbeing.

The impact of poly-victimisation in childhood had severe and ongoing adverse consequences for both men and women that outweighed any obvious gender difference. For people who have experienced childhood maltreatment, it is essential to imbue initiatives with opportunities to understand emotions in relational contexts. Children who are placed in the care of the state must be cared for and, unlike the interviewees in this thesis, free from further childhood maltreatment. A therapeutic web should be established to stop the systemic issues identified in this thesis by providing cohesive and coherent services in a timely fashion for children and adults affected by the cycle of family harm. In conclusion, adopting practices that are informed by understandings of trauma, gender, and Indigenous knowledge are needed to replace the intergenerational transmission of trauma and violence with hope and wellbeing.

text: Making the invisible visible: Exploring the complex pathways between childhood experiences of maltreatment and the perpetration of family harm Preventing family harm and providing care for those affected is a high priority for governments and social services worldwide. Adverse consequences of family harm continue to place demands on justice, mental health and care and protection services. The costs to individuals, families and communities are beyond measure, given that rates of family harm are under-reported. Quantitative researchers have demonstrated a link between childhood maltreatment and family harm perpetration with existing psychological theories used to explain this link. However, mainstream theories were first developed many decades ago, at a time when the notion of gender was not inclusively factored into theory development. Neither were they developed with or by Indigenous peoples, calling into question the translatability of mainstream theories for stopping the intergenerational transmission of trauma and violence. 
The main aim of this thesis was to explore the relationship between childhood maltreatment and the perpetration of family harm by investigating two research questions. How could psychological theories better explain the pathways between childhood experiences of maltreatment and family harm perpetration? And, to what extent do psychological theories about the cycle of family harm reflect the experiences of Māori and non-Māori men and women in Aotearoa New Zealand? To answer these questions, interviews were conducted with 16 individuals who self-identified as perpetrating family harm and had childhood histories of maltreatment. (n=8 men, n=8 women). Purposive sampling ensured an equal number of Māori (Indigenous people of Aotearoa New Zealand) and non-Māori participated in the research. Thematic analysis was utilised to examine the personal conceptualisations regarding the association between experiences of childhood maltreatment and subsequent perpetration of family harm. The core corpus of data explored the maltreatment-family harm relationship within and between Māori and non-Māori men and women. This thesis is comprised of three studies that investigate the intergenerational transmission of trauma and violence.

The first study analysed the interviews of the seven participants removed from their families of origin as children. All described ongoing experiences of poly-victimisation in subsequent placements, whether through adoption, foster or residential settings. When examined alongside all women interviewed in this thesis, men more often reported that their childhood maltreatment was overlooked by professionals. The findings of this study highlighted a relationship between the perpetration of family harm and limited relational and emotional experiences during childhood. Intervention points across the life span were identified to stop the intergenerational transmission of trauma and violence for people removed from their family of origin as children.

The second study focused on the experiences of the eight Māori men and women interviewed. A culture of silence surrounding childhood maltreatment pervaded all interviewees’ childhood experiences. However, additional issues, including cultural isolation, were evident for Māori from the adults and professionals charged with their care. Māori interviewees identified three core Indigenous concepts that facilitated healing and intergenerational wellbeing: Wairua (spiritual connection), Pou (becoming a symbol of strength and support for self and others), and Tūrangawaewae (finding a sense of belonging). A return to Indigenous knowledge and practices was integral to stopping the intergenerational transmission of trauma and violence. This highlights the importance of privileging Indigenous knowledge in existing theoretical understanding of the cycle of family harm and incorporation in prevention initiatives.

The final study explored the impact of psychological distress within the cycle of family harm. Everyone interviewed experienced severe adverse trauma reactions linked to mental health and addiction issues, self-harm and suicidality, and instances of family harm. A significant barrier to psychological and familial wellbeing was the lack of access to integrated models of care capable of responding to complex and intertwined issues in trauma informed and Indigenous informed ways. Thus, family harm, trauma and mental health and addiction services need to work together to tailor and deliver treatment according to the individual and family needs to break the cycle of family harm and ongoing adverse life course trajectories. 

This research identifies significant limitations in the psychological theories that usually contribute to thinking about family harm. There has been a particular failure to develop a theory that accounts for the heterogeneous cultural and gendered experiences of the cycle of family harm. Going forward, expanding the? view of traditional psychological theories of intergenerational trauma and violence is required to account for the historical trauma of colonisation and the ongoing adverse consequences for Indigenous communities. Family harm prevention initiatives must be led by and/or developed in partnership with and by Indigenous peoples to ensure responsivity through active incorporation of traditional practices for intergenerational healing and wellbeing.

The impact of poly-victimisation in childhood had severe and ongoing adverse consequences for both men and women that outweighed any obvious gender difference. For people who have experienced childhood maltreatment, it is essential to imbue initiatives with opportunities to understand emotions in relational contexts. Children who are placed in the care of the state must be cared for and, unlike the interviewees in this thesis, free from further childhood maltreatment. A therapeutic web should be established to stop the systemic issues identified in this thesis by providing cohesive and coherent services in a timely fashion for children and adults affected by the cycle of family harm. In conclusion, adopting practices that are informed by understandings of trauma, gender, and Indigenous knowledge are needed to replace the intergenerational transmission of trauma and violence with hope and wellbeing.

year: 2022