title: Optical full Hadamard matrix multiplexing and noise effects

authors: Streeter, Lee

subjects: Hadamard multiplexing

abstract: Hadamard multiplexing provides a considerable SNR boost over additive random noise but Poisson noise such as photon noise reduces the boost. We develop the theory for full H-matrix Hadamard transform imaging under additive and Poisson noise effects. We show that H-matrix encoding results in no effect on average on the noise level due to Poisson noise sources while preferentially reducing additive noise. We use this result to explain the wavelength-dependent varying SNR boost in a Hadamard hyperspectral imager and argue that such a preferential boost is useful when the main noise source is indeterminant or varying.

text: Optical full Hadamard matrix multiplexing and noise effects Hadamard multiplexing provides a considerable SNR boost over additive random noise but Poisson noise such as photon noise reduces the boost. We develop the theory for full H-matrix Hadamard transform imaging under additive and Poisson noise effects. We show that H-matrix encoding results in no effect on average on the noise level due to Poisson noise sources while preferentially reducing additive noise. We use this result to explain the wavelength-dependent varying SNR boost in a Hadamard hyperspectral imager and argue that such a preferential boost is useful when the main noise source is indeterminant or varying.

year: 2009

title: Identifying Mineralogical and Geochemical Vectors towards the Epithermal Au-Ag Correnso Mine, Waihi

authors: Singh, Ravinder Sardul

subjects: Correnso Deposit

abstract: The Au-Ag rich Correnso vein is a low sulphidation epithermal deposit located east of Waihi and is named after the clay mineral corrensite. Hydrothermally altered andesitic and dacitic host rocks of the Waipupu Formation, informally subdivided into Upper Andesite and Lower Andesite units, contain Au-Ag rich quartz veins. The interaction of hot, dominantly meteoric water with the host rocks causes mineralogical and geochemical changes. Hydrothermal alteration manifested as mineralogical alteration and geochemical signatures can help in identifying vectors to constrain potential areas of enhanced mineralization for exploration purposes. Hydrothermal alteration has been suggested to have potential as exploration vector for epithermal deposits in particular as alteration halos can extend up to considerable distances (Christie et al., 2001; Simpson and Mauk, 2004). 
Visual core logging, petrography, pXRF, and Aqua-Regia/2-Acid Digest (ICP-MS) analysis were used in this study to analyse and quantify alteration zonation patterns and trace element metasomatism in order to identify vectors towards the mineralisation. Results suggest a clear mineralogical and geochemical alteration zonation pattern around the vein system. The unaltered, moderately altered and highly altered rocks are often adjacent to one another, implying that hydrothermal fluids have migrated through the host rocks in a highly heterogeneous fashion. The migration of fluids is likely controlled by both primary and secondary (e.g. fault/fracture) permeability. The overall mineralogical pattern can be described as quartz ± adularia ± sericite assemblage which is similar to the adjacent deposits of the Waihi area. Alteration zonation in the host rocks consists of potassic alteration proximal to the vein system surrounded by sericitic alteration, with illite-smectite dominated argillic assemblage overprinting both alteration types. Propylitic alteration is more prominent to the outward zones and distal to the mineralisation. Geochemical analysis show enrichment of pathfinder elements such as As, As, Sb, Hg, Zn, Pb, Se, and K and depletion of Cu, Te and Se.

text: Identifying Mineralogical and Geochemical Vectors towards the Epithermal Au-Ag Correnso Mine, Waihi The Au-Ag rich Correnso vein is a low sulphidation epithermal deposit located east of Waihi and is named after the clay mineral corrensite. Hydrothermally altered andesitic and dacitic host rocks of the Waipupu Formation, informally subdivided into Upper Andesite and Lower Andesite units, contain Au-Ag rich quartz veins. The interaction of hot, dominantly meteoric water with the host rocks causes mineralogical and geochemical changes. Hydrothermal alteration manifested as mineralogical alteration and geochemical signatures can help in identifying vectors to constrain potential areas of enhanced mineralization for exploration purposes. Hydrothermal alteration has been suggested to have potential as exploration vector for epithermal deposits in particular as alteration halos can extend up to considerable distances (Christie et al., 2001; Simpson and Mauk, 2004). 
Visual core logging, petrography, pXRF, and Aqua-Regia/2-Acid Digest (ICP-MS) analysis were used in this study to analyse and quantify alteration zonation patterns and trace element metasomatism in order to identify vectors towards the mineralisation. Results suggest a clear mineralogical and geochemical alteration zonation pattern around the vein system. The unaltered, moderately altered and highly altered rocks are often adjacent to one another, implying that hydrothermal fluids have migrated through the host rocks in a highly heterogeneous fashion. The migration of fluids is likely controlled by both primary and secondary (e.g. fault/fracture) permeability. The overall mineralogical pattern can be described as quartz ± adularia ± sericite assemblage which is similar to the adjacent deposits of the Waihi area. Alteration zonation in the host rocks consists of potassic alteration proximal to the vein system surrounded by sericitic alteration, with illite-smectite dominated argillic assemblage overprinting both alteration types. Propylitic alteration is more prominent to the outward zones and distal to the mineralisation. Geochemical analysis show enrichment of pathfinder elements such as As, As, Sb, Hg, Zn, Pb, Se, and K and depletion of Cu, Te and Se.

year: 2015

title: Maori participation in higher education: Tainui graduates from the University of Waikato, 1992 to 1997

authors: Tiakiwai, Sarah-Jane

abstract: This thesis is an examination of what factors contribute to the success of Maori who participate in higher education. The thesis is informed by the experiences of nine Tainui tribal members who received scholarships from the Tainui Maori Trust Board and who graduated from the University of Waikato between 1992 and 1997. 

The thesis addresses two questions: what factors contributed to the success of Tainui graduates at the University of Waikato? What effect did programmes, policies and initiatives offered by the University of Waikato and the Tainui Maori Trust Board have on the academic success of Tainui graduates at the University of Waikato? 

There are three main components to the thesis: a brief history of the University of Waikato and an examination of three documents (University of Waikato Charter 1991; Paetawhiti, the strategic plan 1993; Academic Audit Unit report 1997) and how they pertain to Maori; a history of the Tainui Maori Trust Board and an examination of the Tainui Education Strategy (1986, 1991), its review (1993) and scholarship programmes; and a study and analysis of the experiences of nine Tainui graduates from the University of Waikato. 

Argued from an eclectic theoretical and methodological position, drawing from indigenous and western theories and research practices that emphasise a kaupapa Maori and tribal approach, the thesis identifies multiple factors that have contributed to the success of the Tainui graduates. These factors include family and parental support, mentoring, the role of finances, institutional support, and identity. 

The thesis finds through examination of the documents, that the policies, initiatives and programmes of the Tainui Maori Trust Board and the University of Waikato have ambiguous and at times conflicting aims and objectives in regard to Maori participation and graduation from higher education. The thesis also finds that the experiences of the graduates reveal that neither the Tainui Maori Trust Board nor policies relating to Maori at the University of Waikato played significant roles in the success of the Tainui graduates. Rather, the thesis finds that the success of the graduates is largely borne by their own efforts, which reflect western notions of success, but which also reinforce their identity as Maori, and as Tainui tribal members. 

The thesis suggests that both the Tainui Maori Trust Board and the University of Waikato review their relationships with their tribal and Maori members (respectively), and recommendations are made to help develop a greater awareness of the contribution that both organisations can make to the success of Maori university students.

text: Maori participation in higher education: Tainui graduates from the University of Waikato, 1992 to 1997 This thesis is an examination of what factors contribute to the success of Maori who participate in higher education. The thesis is informed by the experiences of nine Tainui tribal members who received scholarships from the Tainui Maori Trust Board and who graduated from the University of Waikato between 1992 and 1997. 

The thesis addresses two questions: what factors contributed to the success of Tainui graduates at the University of Waikato? What effect did programmes, policies and initiatives offered by the University of Waikato and the Tainui Maori Trust Board have on the academic success of Tainui graduates at the University of Waikato? 

There are three main components to the thesis: a brief history of the University of Waikato and an examination of three documents (University of Waikato Charter 1991; Paetawhiti, the strategic plan 1993; Academic Audit Unit report 1997) and how they pertain to Maori; a history of the Tainui Maori Trust Board and an examination of the Tainui Education Strategy (1986, 1991), its review (1993) and scholarship programmes; and a study and analysis of the experiences of nine Tainui graduates from the University of Waikato. 

Argued from an eclectic theoretical and methodological position, drawing from indigenous and western theories and research practices that emphasise a kaupapa Maori and tribal approach, the thesis identifies multiple factors that have contributed to the success of the Tainui graduates. These factors include family and parental support, mentoring, the role of finances, institutional support, and identity. 

The thesis finds through examination of the documents, that the policies, initiatives and programmes of the Tainui Maori Trust Board and the University of Waikato have ambiguous and at times conflicting aims and objectives in regard to Maori participation and graduation from higher education. The thesis also finds that the experiences of the graduates reveal that neither the Tainui Maori Trust Board nor policies relating to Maori at the University of Waikato played significant roles in the success of the Tainui graduates. Rather, the thesis finds that the success of the graduates is largely borne by their own efforts, which reflect western notions of success, but which also reinforce their identity as Maori, and as Tainui tribal members. 

The thesis suggests that both the Tainui Maori Trust Board and the University of Waikato review their relationships with their tribal and Maori members (respectively), and recommendations are made to help develop a greater awareness of the contribution that both organisations can make to the success of Maori university students.

year: 2001