title: Computer graphics techniques for modeling page turning

authors: Liesaputra, Veronica

subjects: computer graphics models

abstract: Turning the page is a mechanical part of the cognitive act of reading that we do literally unthinkingly. Interest in realistic book models for digital libraries and other online documents is growing. Yet actually producing a computer graphics implementation for modeling page turning is a challenging undertaking. There are many possible foundations: two-dimensional models that use reflection and rotation; geometrical models using cylinders or cones; mass-spring models that simulate the mechanical properties of paper at varying degrees of fidelity; finite-element models that directly compute the actual forces within a piece of paper. Even the simplest methods are not trivial, and the more sophisticated ones involve detailed physical and mathematical models. The variety, intricacy and complexity of possible ways of simulating this fundamental act of reading is virtually unknown.
This paper surveys computer graphics models for page turning. It combines a tutorial introduction that covers the range of possibilities and complexities with a mathematical synopsis of each model in sufficient detail to serve as a basis for implementation. Illustrations are included that are generated by our implementations of each model. The techniques presented include geometric methods (both two- and three-dimensional), mass-spring models with varying degrees of accuracy and complexity, and finite-element models. We include a detailed comparison of experimentally-determined computation time and subjective visual fidelity for all methods discussed. The simpler techniques support convincing real-time implementations on ordinary workstations.

text: Computer graphics techniques for modeling page turning Turning the page is a mechanical part of the cognitive act of reading that we do literally unthinkingly. Interest in realistic book models for digital libraries and other online documents is growing. Yet actually producing a computer graphics implementation for modeling page turning is a challenging undertaking. There are many possible foundations: two-dimensional models that use reflection and rotation; geometrical models using cylinders or cones; mass-spring models that simulate the mechanical properties of paper at varying degrees of fidelity; finite-element models that directly compute the actual forces within a piece of paper. Even the simplest methods are not trivial, and the more sophisticated ones involve detailed physical and mathematical models. The variety, intricacy and complexity of possible ways of simulating this fundamental act of reading is virtually unknown.
This paper surveys computer graphics models for page turning. It combines a tutorial introduction that covers the range of possibilities and complexities with a mathematical synopsis of each model in sufficient detail to serve as a basis for implementation. Illustrations are included that are generated by our implementations of each model. The techniques presented include geometric methods (both two- and three-dimensional), mass-spring models with varying degrees of accuracy and complexity, and finite-element models. We include a detailed comparison of experimentally-determined computation time and subjective visual fidelity for all methods discussed. The simpler techniques support convincing real-time implementations on ordinary workstations.

year: 2007-10-24

title: Ecology of the invertebrate predatory fauna across Centre Bank, Tauranga Harbour

authors: Putt, Fiona Gloria

subjects: Centre Bank

abstract: The distribution, abundance, population size structure and behaviour of three common invertebrate predators were studied on Centre Bank, the flood-tidal delta of Tauranga Harbour. The study assessed the role of the predators in controlling the distribution and abundance of bivalve shellfish and provided information concerning the biology of Centre Bank for Port of Tauranga Ltd.
Two broad-scale surveys were conducted to describe the broad-scale spatial patterns of Patiriella regularis, Coscinasterias calamaria and Cominella adspersa. Results found P. regularis was the numerically dominant species across Centre Bank and it maintained a widespread distribution over the sampling period. C. calamaria was of low abundance and typically exhibited a patchy distribution. C. adspersa was also found to be of low abundance and similarly distributed as C. calamaria. Size structures of all 3 species comprised mostly adults in both surveys.
Temporal monitoring at finer scales was undertaken, two-monthly, to describe small-scale spatial patterns. P. regularis was found at similar densities to that of the large-scale surveys and it was the most prevalent species across the grid; C. calamaria was present at higher abundances within a small patch of the grid and appeared stable over time. C. adspersa was initially absent from the grid, but became more abundant and widespead over the 9 month sampling period.
Investigations included monitoring the natural movement behaviour of C. adspersa in relation to tidal currents and the body condition. Results showed the directions moved and distances displaced by C. adspersa may be influenced by the rate and direction of current movement and therefore potentially influencing the dispersal ability of C. adspersa, in relation to available prey. An experiment to determine the body condition of C. adspersa in the field suggested that food deprivation may be less detrimental than first realised, or that C. adspersa is able to feed on a greater variety of food types than known of.
Little evidence was found that indicated predation was an important mechanism controlling bivalve populations across Centre Bank. However, predators may be potentially important as scavengers of decaying or dead organisms. Their predatory activities may also provide shell substrate for macroalgae, and this, in combination with dense aggregations of C. calamaria, appeared to provide habitat for small fishes.

text: Ecology of the invertebrate predatory fauna across Centre Bank, Tauranga Harbour The distribution, abundance, population size structure and behaviour of three common invertebrate predators were studied on Centre Bank, the flood-tidal delta of Tauranga Harbour. The study assessed the role of the predators in controlling the distribution and abundance of bivalve shellfish and provided information concerning the biology of Centre Bank for Port of Tauranga Ltd.
Two broad-scale surveys were conducted to describe the broad-scale spatial patterns of Patiriella regularis, Coscinasterias calamaria and Cominella adspersa. Results found P. regularis was the numerically dominant species across Centre Bank and it maintained a widespread distribution over the sampling period. C. calamaria was of low abundance and typically exhibited a patchy distribution. C. adspersa was also found to be of low abundance and similarly distributed as C. calamaria. Size structures of all 3 species comprised mostly adults in both surveys.
Temporal monitoring at finer scales was undertaken, two-monthly, to describe small-scale spatial patterns. P. regularis was found at similar densities to that of the large-scale surveys and it was the most prevalent species across the grid; C. calamaria was present at higher abundances within a small patch of the grid and appeared stable over time. C. adspersa was initially absent from the grid, but became more abundant and widespead over the 9 month sampling period.
Investigations included monitoring the natural movement behaviour of C. adspersa in relation to tidal currents and the body condition. Results showed the directions moved and distances displaced by C. adspersa may be influenced by the rate and direction of current movement and therefore potentially influencing the dispersal ability of C. adspersa, in relation to available prey. An experiment to determine the body condition of C. adspersa in the field suggested that food deprivation may be less detrimental than first realised, or that C. adspersa is able to feed on a greater variety of food types than known of.
Little evidence was found that indicated predation was an important mechanism controlling bivalve populations across Centre Bank. However, predators may be potentially important as scavengers of decaying or dead organisms. Their predatory activities may also provide shell substrate for macroalgae, and this, in combination with dense aggregations of C. calamaria, appeared to provide habitat for small fishes.

year: 1996

title: Neighbours at Puhoi River: A cross-cultural dual biography of Te Hemara Tauhia(1815-1891) and Martin Krippner(1817-1894)

authors: Eddy, Anne

subjects: Cross-cultural

abstract: This thesis seeks to re-construct the biographies of two relatively obscure, yet fascinating and controversial players in the history of Aotearoa New Zealand. Both historical figures were initiators and leaders of neighbouring settlements: the rangatira, Te Hemara Tauhia (1815 – 1891), in his role as chief of the Te Kawerau/Ngāti Rongo hapū of the Ngāti Whātua iwi, re-occupying ancestral lands after living in captivity with Ngāpuhi, and the former Austrian captain, Martin Krippner (1817 – 1894), organiser of an Austrian-Bohemian settlement made possible under the Auckland Provincial Government land grant scheme. Despite their efforts for each community, both men were accused by their own people of misusing their positions for personal gains. Te Hemara Tauhia was blamed for selling off tribal lands to cover personal debts. Martin Krippner was never forgiven for promising his Bohemian compatriots a ‘land of milk and honey’ while leading them to near starvation and struggle within dense New Zealand bush, and subsequently into war in the Waikato where Krippner was commissioned captain in the Waikato Militia.
Focussing on three main objectives, this cross-cultural dual biography provides an original contribution to historical scholarship: Firstly, it looks behind the myths that have been created around Te Hemara Tauhia and Martin Krippner; it thoroughly examines what both men did and how social, economic and political circumstances influenced their motivations and choices at that particular time. Secondly, placing Tauhia’s and Krippner’s biographies side-by-side provides a novel view of a range of historical phenomena from both Tangata Whenua (indigenous peoples) and European settlers (Pākehā) perspectives. Looking at the same events from different angles and perspectives, a cross-cultural, dual biography can act like a prismatic tool, revealing the complexity of a shared history. The third aim of this research encompasses my intention to contribute to and to participate in a dialogue between ethnic groups in Aotearoa New Zealand, especially between Māori and Pākehā, in order to challenge stereotypes and generalisations based on lack of knowledge of historical and cultural contexts.

text: Neighbours at Puhoi River: A cross-cultural dual biography of Te Hemara Tauhia(1815-1891) and Martin Krippner(1817-1894) This thesis seeks to re-construct the biographies of two relatively obscure, yet fascinating and controversial players in the history of Aotearoa New Zealand. Both historical figures were initiators and leaders of neighbouring settlements: the rangatira, Te Hemara Tauhia (1815 – 1891), in his role as chief of the Te Kawerau/Ngāti Rongo hapū of the Ngāti Whātua iwi, re-occupying ancestral lands after living in captivity with Ngāpuhi, and the former Austrian captain, Martin Krippner (1817 – 1894), organiser of an Austrian-Bohemian settlement made possible under the Auckland Provincial Government land grant scheme. Despite their efforts for each community, both men were accused by their own people of misusing their positions for personal gains. Te Hemara Tauhia was blamed for selling off tribal lands to cover personal debts. Martin Krippner was never forgiven for promising his Bohemian compatriots a ‘land of milk and honey’ while leading them to near starvation and struggle within dense New Zealand bush, and subsequently into war in the Waikato where Krippner was commissioned captain in the Waikato Militia.
Focussing on three main objectives, this cross-cultural dual biography provides an original contribution to historical scholarship: Firstly, it looks behind the myths that have been created around Te Hemara Tauhia and Martin Krippner; it thoroughly examines what both men did and how social, economic and political circumstances influenced their motivations and choices at that particular time. Secondly, placing Tauhia’s and Krippner’s biographies side-by-side provides a novel view of a range of historical phenomena from both Tangata Whenua (indigenous peoples) and European settlers (Pākehā) perspectives. Looking at the same events from different angles and perspectives, a cross-cultural, dual biography can act like a prismatic tool, revealing the complexity of a shared history. The third aim of this research encompasses my intention to contribute to and to participate in a dialogue between ethnic groups in Aotearoa New Zealand, especially between Māori and Pākehā, in order to challenge stereotypes and generalisations based on lack of knowledge of historical and cultural contexts.

year: 2017