title: Renewable energy perspectives

authors: Daya-Winterbottom, Trevor

abstract: From the mountains to the sea, the Waikato region of New Zealand stretches from the snowcapped mountains of the North Island’s volcanic plateau surrounding Lake Taupo, through the broad Waikato River valley to the Tasman Sea. The region has the “capacity to power” up to 50 per cent of New Zealand, and exports over 75 per cent of the “electricity generated … to other regions”. The primary sources of electricity generation in the Waikato region are hydro, geothermal, and thermal (coal and gas); and recent growth in electricity development in the region has focused on geothermal and gas-fired generation. However, with “peaking” production from the Maui gas field offshore from the Taranaki coast, and the increased emphasis on a 90 per cent renewable electricity generation target by 2025: 
… the region is likely to play an important role in the development of future renewable electricity generation nationally. 
For example, limited capacity for new hydro dams along the Waikato River and constraints on further “assimilating discharges” for cooling from thermal power stations due to increasing demand for freshwater underpins the continued interest in geothermal and wind power and the interest in “emerging” technologies such as “underground coal gasification” and “marine energy”. In particular, accessing north Waikato coal reserves (over one billion tonnes), that is currently impractical and uneconomic using “conventional” open cast or deep mining methods, could become “a real possibility” using these new technologies. Against this background the Royal Society of New Zealand recommended that electricity generation should make the “transition” to renewable energy sources by 2020, including the use of less carbon intense bridging fuels, and with a “commitment to zero carbon emissions” from fossil-fuel generation through capture and storage techniques.

text: Renewable energy perspectives From the mountains to the sea, the Waikato region of New Zealand stretches from the snowcapped mountains of the North Island’s volcanic plateau surrounding Lake Taupo, through the broad Waikato River valley to the Tasman Sea. The region has the “capacity to power” up to 50 per cent of New Zealand, and exports over 75 per cent of the “electricity generated … to other regions”. The primary sources of electricity generation in the Waikato region are hydro, geothermal, and thermal (coal and gas); and recent growth in electricity development in the region has focused on geothermal and gas-fired generation. However, with “peaking” production from the Maui gas field offshore from the Taranaki coast, and the increased emphasis on a 90 per cent renewable electricity generation target by 2025: 
… the region is likely to play an important role in the development of future renewable electricity generation nationally. 
For example, limited capacity for new hydro dams along the Waikato River and constraints on further “assimilating discharges” for cooling from thermal power stations due to increasing demand for freshwater underpins the continued interest in geothermal and wind power and the interest in “emerging” technologies such as “underground coal gasification” and “marine energy”. In particular, accessing north Waikato coal reserves (over one billion tonnes), that is currently impractical and uneconomic using “conventional” open cast or deep mining methods, could become “a real possibility” using these new technologies. Against this background the Royal Society of New Zealand recommended that electricity generation should make the “transition” to renewable energy sources by 2020, including the use of less carbon intense bridging fuels, and with a “commitment to zero carbon emissions” from fossil-fuel generation through capture and storage techniques.

year: 2014

title: Construction of lattice rules for multiple integration based on a weighted discrepancy

authors: Sinescu, Vasile

subjects: Lattice rules

abstract: High-dimensional integrals arise in a variety of areas, including quantum physics, the physics and chemistry of molecules, statistical mechanics and more recently, in financial applications.
In order to approximate multidimensional integrals, one may use Monte Carlo methods in which the quadrature points are generated randomly or quasi-Monte Carlo methods, in which points are generated deterministically. One particular class of quasi-Monte Carlo methods for multivariate integration is represented by lattice rules. Lattice rules constructed throughout this thesis allow good approximations to integrals of functions belonging to certain
weighted function spaces. These function spaces were proposed as an explanation as to why integrals in many variables appear to be successfully approximated although the standard theory indicates that the number of quadrature
points required for reasonable accuracy would be astronomical because of the large number of variables.
The purpose of this thesis is to contribute to theoretical results regarding the construction of lattice rules for multiple integration. We consider both lattice rules for integrals over the unit cube and lattice rules suitable for integrals over Euclidean space. The research reported throughout the thesis is devoted to finding the generating vector required to produce lattice rules that have what is termed a  low weighted discrepancy . In simple terms, the  discrepancy  is a measure of the uniformity of the distribution of the quadrature points or in other settings, a worst-case error. One of the assumptions used in these weighted function spaces is that variables are arranged in the decreasing order of their importance and the assignment of weights in this situation results in so-called  product weights . In other applications it is rather the importance of group of variables that matters. This situation is modelled by using function spaces in which the weights are  general . In the weighted
settings mentioned above, the quality of the lattice rules is assessed by the  weighted discrepancy  mentioned earlier. Under appropriate conditions on the weights, the lattice rules constructed here produce a convergence rate of the error that ranges 
from O(n−1/2) to the (believed) optimal O(n−1+δ) for any δ gt 0, with the involved constant independent of the dimension.

text: Construction of lattice rules for multiple integration based on a weighted discrepancy High-dimensional integrals arise in a variety of areas, including quantum physics, the physics and chemistry of molecules, statistical mechanics and more recently, in financial applications.
In order to approximate multidimensional integrals, one may use Monte Carlo methods in which the quadrature points are generated randomly or quasi-Monte Carlo methods, in which points are generated deterministically. One particular class of quasi-Monte Carlo methods for multivariate integration is represented by lattice rules. Lattice rules constructed throughout this thesis allow good approximations to integrals of functions belonging to certain
weighted function spaces. These function spaces were proposed as an explanation as to why integrals in many variables appear to be successfully approximated although the standard theory indicates that the number of quadrature
points required for reasonable accuracy would be astronomical because of the large number of variables.
The purpose of this thesis is to contribute to theoretical results regarding the construction of lattice rules for multiple integration. We consider both lattice rules for integrals over the unit cube and lattice rules suitable for integrals over Euclidean space. The research reported throughout the thesis is devoted to finding the generating vector required to produce lattice rules that have what is termed a  low weighted discrepancy . In simple terms, the  discrepancy  is a measure of the uniformity of the distribution of the quadrature points or in other settings, a worst-case error. One of the assumptions used in these weighted function spaces is that variables are arranged in the decreasing order of their importance and the assignment of weights in this situation results in so-called  product weights . In other applications it is rather the importance of group of variables that matters. This situation is modelled by using function spaces in which the weights are  general . In the weighted
settings mentioned above, the quality of the lattice rules is assessed by the  weighted discrepancy  mentioned earlier. Under appropriate conditions on the weights, the lattice rules constructed here produce a convergence rate of the error that ranges 
from O(n−1/2) to the (believed) optimal O(n−1+δ) for any δ gt 0, with the involved constant independent of the dimension.

year: 2008

title: Boy, Oh Boy!: An interview with Taika Waititi

authors: Lealand, Geoff

subjects: film

abstract: An Interview with Taika Waititi.

text: Boy, Oh Boy!: An interview with Taika Waititi An Interview with Taika Waititi.

year: 2011