title: Tyings in linear systems of equations modelled with positive and negative penalty functions

authors: Askes, Harm

subjects: constraints

abstract: In this short note, we focus on tyings (constraints that relate multiple degrees of freedom) modelled by means of penalty functions. In contrast to what is commonly thought, it is possible to obtain convergent results when negative penalty parameters are taken. A mathematical proof and an illustrating example are provided. In particular, we have proven that the results obtained with positive and negative penalty parameters enclose the exact solution from opposite sides. To this end, we have investigated a pseudo-force that is defined as the derivative of the constraint with respect to the inverse penalty parameter.

text: Tyings in linear systems of equations modelled with positive and negative penalty functions In this short note, we focus on tyings (constraints that relate multiple degrees of freedom) modelled by means of penalty functions. In contrast to what is commonly thought, it is possible to obtain convergent results when negative penalty parameters are taken. A mathematical proof and an illustrating example are provided. In particular, we have proven that the results obtained with positive and negative penalty parameters enclose the exact solution from opposite sides. To this end, we have investigated a pseudo-force that is defined as the derivative of the constraint with respect to the inverse penalty parameter.

year: 2008

title: Quaternary tephra marker beds and their potential for palaeoenvironmental reconstruction on Chatham Island, east of New Zealand, southwest Pacific Ocean

authors: Holt, Katherine A.

subjects: Kawakawa tephra

abstract: Tephras provide one of the most reliable methods of time control and synchronisation within Quaternary sequences. We report on the identification of two widespread rhyolitic tephras - the Kawakawa and Rangitawa tephras - preserved in extensive peat deposits on Chatham Island  900 km east of New Zealand. The tephras, both products of supereruptions from the Taupo Volcanic Zone, occur as pale, fine-ash dominated layers typically 10-150 mm thick. Mineralogically they are dominated by rhyolitic glass, together with subordinate amounts of quartz, feldspar, hypersthene, hornblende, Fe-Ti oxides and zircon. Phlogopite/biotite was identified additionally in Rangitawa Tephra. Ages for each tephra were obtained via mineralogical and major element glass composition-based correlation with well-dated equivalent deposits on mainland New Zealand, and we also obtained a new zircon fission-track age for Rangitawa Tephra (350 ± 50 ka) on Chatham Island. Both tephras were erupted at critical times for palaeoenvironmental reconstructions in the New Zealand region: the Kawakawa at ca. 27 cal. ka, near the beginning of the  extended  LGM early in marine isotope stage (MIS) 2; and the Rangitawa at ca. 350 ka near the end of MIS 10. The time constraints provided by the tephras demonstrate that Chatham Island peats contain long-distance pollen derived from mainland New Zealand, which provides a reliable proxy for identifying glacial-interglacial climate conditions, in this case during the MIS 11-10 and MIS 2-1 cycles. The two tephras thus provide important chronostratigraphic tie-points that facilitate correlation and synchronisation not only across the Quaternary deposits of the Chatham Islands group but also with climatically significant terrestrial and marine records in the wider New Zealand region.

text: Quaternary tephra marker beds and their potential for palaeoenvironmental reconstruction on Chatham Island, east of New Zealand, southwest Pacific Ocean Tephras provide one of the most reliable methods of time control and synchronisation within Quaternary sequences. We report on the identification of two widespread rhyolitic tephras - the Kawakawa and Rangitawa tephras - preserved in extensive peat deposits on Chatham Island  900 km east of New Zealand. The tephras, both products of supereruptions from the Taupo Volcanic Zone, occur as pale, fine-ash dominated layers typically 10-150 mm thick. Mineralogically they are dominated by rhyolitic glass, together with subordinate amounts of quartz, feldspar, hypersthene, hornblende, Fe-Ti oxides and zircon. Phlogopite/biotite was identified additionally in Rangitawa Tephra. Ages for each tephra were obtained via mineralogical and major element glass composition-based correlation with well-dated equivalent deposits on mainland New Zealand, and we also obtained a new zircon fission-track age for Rangitawa Tephra (350 ± 50 ka) on Chatham Island. Both tephras were erupted at critical times for palaeoenvironmental reconstructions in the New Zealand region: the Kawakawa at ca. 27 cal. ka, near the beginning of the  extended  LGM early in marine isotope stage (MIS) 2; and the Rangitawa at ca. 350 ka near the end of MIS 10. The time constraints provided by the tephras demonstrate that Chatham Island peats contain long-distance pollen derived from mainland New Zealand, which provides a reliable proxy for identifying glacial-interglacial climate conditions, in this case during the MIS 11-10 and MIS 2-1 cycles. The two tephras thus provide important chronostratigraphic tie-points that facilitate correlation and synchronisation not only across the Quaternary deposits of the Chatham Islands group but also with climatically significant terrestrial and marine records in the wider New Zealand region.

year: 2010

title: Genealogical Violence: Mormon (Mis)Appropriation of Māori Cultural Memory through Falsification of Whakapapa

authors: Simon, Hemopereki

subjects: whakapapa

abstract: The study examines how members of the historically white possessive and supremacist Church of Jesus Christ of Latter-day Saints in the United States (mis)appropriated Māori genealogy, known as whakapapa. The Mormon use of whakapapa to promote Mormon cultural memory and narratives perpetuates settler/invader colonialism and white supremacy, as this paper shows. The research discusses Church racism against Native Americans and Pacific Peoples. This paper uses Anthropologist Thomas Murphy’s scholarship to demonstrate how problematic the Book of Mormon’s religio-colonial identity of Lamanites is for these groups. Application of Aileen Moreton-Robinson’s white possessive doctrine and Hemopereki Simon’s adaptation to cover Church-Indigenous relations and the salvation contract is discussed. We explore collective and cultural memory and discuss key Māori concepts like Mana, Taonga, Tapu, and Whakapapa. A brief review of LDS scholar Louis C. Midgley’s views on Church culture, including Herewini Jones’s whakapapa wānanga, is followed by a discussion of Māori cultural considerations and issues. The paper concludes that the alteration perpetuates settler/invader colonialism and Pacific peoples’ racialization and white supremacy. Genetics science and human migration studies contradict Mormon identity narratives and suggest the BOM is spiritual rather than historical. Finally, the paper suggests promoting intercultural engagement on Mormon (mis)appropriation of taonga Māori.

text: Genealogical Violence: Mormon (Mis)Appropriation of Māori Cultural Memory through Falsification of Whakapapa The study examines how members of the historically white possessive and supremacist Church of Jesus Christ of Latter-day Saints in the United States (mis)appropriated Māori genealogy, known as whakapapa. The Mormon use of whakapapa to promote Mormon cultural memory and narratives perpetuates settler/invader colonialism and white supremacy, as this paper shows. The research discusses Church racism against Native Americans and Pacific Peoples. This paper uses Anthropologist Thomas Murphy’s scholarship to demonstrate how problematic the Book of Mormon’s religio-colonial identity of Lamanites is for these groups. Application of Aileen Moreton-Robinson’s white possessive doctrine and Hemopereki Simon’s adaptation to cover Church-Indigenous relations and the salvation contract is discussed. We explore collective and cultural memory and discuss key Māori concepts like Mana, Taonga, Tapu, and Whakapapa. A brief review of LDS scholar Louis C. Midgley’s views on Church culture, including Herewini Jones’s whakapapa wānanga, is followed by a discussion of Māori cultural considerations and issues. The paper concludes that the alteration perpetuates settler/invader colonialism and Pacific peoples’ racialization and white supremacy. Genetics science and human migration studies contradict Mormon identity narratives and suggest the BOM is spiritual rather than historical. Finally, the paper suggests promoting intercultural engagement on Mormon (mis)appropriation of taonga Māori.

year: 2024