title: Informed mutation of wind farm layouts to maximise energy harvest

authors: Mayo, Michael

subjects: Machine learning

abstract: Correct placement of turbines in a wind farm is a critical issue in wind farm design optimisation. While traditional "trial and error"-based approaches suffice for small layouts, automated approaches are required for larger wind farms with turbines numbering in the hundreds. In this paper we propose an evolutionary strategy with a novel mutation operator for identifying wind farm layouts that minimise expected velocity deficit due to wake effects. The mutation operator is based on constructing a predictive model of velocity deficits across a layout so that mutations are inherently biased towards better layouts. This makes the operator informed rather than randomised. We perform a comprehensive evaluation of our approach on five challenging simulated scenarios using a simulation approach acceptable to industry [1]. We then compare our algorithm against two baseline approaches including the Turbine Displacement Algorithm [2]. Our results indicate that our informed mutation approach works effectively, with our approach identifying layouts with the lowest aggregate velocity deficits on all five test scenarios.

text: Informed mutation of wind farm layouts to maximise energy harvest Correct placement of turbines in a wind farm is a critical issue in wind farm design optimisation. While traditional "trial and error"-based approaches suffice for small layouts, automated approaches are required for larger wind farms with turbines numbering in the hundreds. In this paper we propose an evolutionary strategy with a novel mutation operator for identifying wind farm layouts that minimise expected velocity deficit due to wake effects. The mutation operator is based on constructing a predictive model of velocity deficits across a layout so that mutations are inherently biased towards better layouts. This makes the operator informed rather than randomised. We perform a comprehensive evaluation of our approach on five challenging simulated scenarios using a simulation approach acceptable to industry [1]. We then compare our algorithm against two baseline approaches including the Turbine Displacement Algorithm [2]. Our results indicate that our informed mutation approach works effectively, with our approach identifying layouts with the lowest aggregate velocity deficits on all five test scenarios.

year: 2016

title: The new find mine at Waiorongomai

authors: Hart, Philip

abstract: Hone Werahiko and his party, who owned the original New Find claims, undertook the preliminary development of what was universally praised as a valuable property. The large outcrop and the highest levels, driven through steep and rough country, were relatively easy to work, but were high above the county tramway. Encouraging sampling was proved to be correct when crushing commenced, leading to further development, with a series of new levels and connections between the same being driven. But despite hopes of establishing a permanently profitable mine, over time the financial returns declined, particularly because of excessive battery costs and a treatment process that lost an unacceptable percentage of the gold. As the mine workings became larger, incoming water and poor ventilation created problems for miners. To reduce costs, contractors increasingly replaced wages men, but by 1886, with output declining, more efforts were made to lower costs further.
The New Find Company would pay more dividends than any other company on this field. As usual, it was under-capitalized, and as the mine declined so did the share values. Observers urged it to erect its own battery rather than just provide work for the Battery Company, which, after the company collapsed in 1887, acquired its property. The new owners did more development, but, as most of the free-milling ore had been extracted, mining stopped in 1889. Subsequent owners did some more work, but, lacking capital, they sought (and obtained) a small amount of government assistance. Mining revived, briefly, during the boom of 1895, and although there were subsequent plans to reopen the ground it remained abandoned.  
The nature of the mine, with its 100-metre deep stope open to the sky, meant some accidents, but none were fatal.

text: The new find mine at Waiorongomai Hone Werahiko and his party, who owned the original New Find claims, undertook the preliminary development of what was universally praised as a valuable property. The large outcrop and the highest levels, driven through steep and rough country, were relatively easy to work, but were high above the county tramway. Encouraging sampling was proved to be correct when crushing commenced, leading to further development, with a series of new levels and connections between the same being driven. But despite hopes of establishing a permanently profitable mine, over time the financial returns declined, particularly because of excessive battery costs and a treatment process that lost an unacceptable percentage of the gold. As the mine workings became larger, incoming water and poor ventilation created problems for miners. To reduce costs, contractors increasingly replaced wages men, but by 1886, with output declining, more efforts were made to lower costs further.
The New Find Company would pay more dividends than any other company on this field. As usual, it was under-capitalized, and as the mine declined so did the share values. Observers urged it to erect its own battery rather than just provide work for the Battery Company, which, after the company collapsed in 1887, acquired its property. The new owners did more development, but, as most of the free-milling ore had been extracted, mining stopped in 1889. Subsequent owners did some more work, but, lacking capital, they sought (and obtained) a small amount of government assistance. Mining revived, briefly, during the boom of 1895, and although there were subsequent plans to reopen the ground it remained abandoned.  
The nature of the mine, with its 100-metre deep stope open to the sky, meant some accidents, but none were fatal.

year: 2016

title: The cultural perspective: Lakeweed and pest animals

authors: Douglas, Nicki

abstract: I have been with the Department of Conservation for about 15 years now and worked in Rotorua for 11 of those 15 years in various roles. I was lucky enough to be the Operations Manager for Lake Tarawera so I have a very strong association from a practitioner perspective. Practitioner is probably the key word for me. Most of my korero today will be based on experience and practice in working with communities and that is my area of expertise. I will talk about collective impact. It does say that I am talking about lake weeds and pests and I will mention them at least twice.

text: The cultural perspective: Lakeweed and pest animals I have been with the Department of Conservation for about 15 years now and worked in Rotorua for 11 of those 15 years in various roles. I was lucky enough to be the Operations Manager for Lake Tarawera so I have a very strong association from a practitioner perspective. Practitioner is probably the key word for me. Most of my korero today will be based on experience and practice in working with communities and that is my area of expertise. I will talk about collective impact. It does say that I am talking about lake weeds and pests and I will mention them at least twice.

year: 2017