title: Naive Bayes for text classification with unbalanced classes

authors: Frank, Eibe

subjects: Science & Technology

abstract: Multinomial naive Bayes (MNB) is a popular method for document classification due to its computational efficiency and relatively good predictive performance. It has recently been established that predictive performance can be improved further by appropriate data transformations [1,2]. In this paper, we present another transformation that is designed to combat a potential problem with the application of MNB to unbalanced datasets. We propose an appropriate correction by adjusting attribute priors. This correction can be implemented as another data normalization step, and we show that it can significantly improve the area under the ROC curve. We also show that the modified version of MNB is very closely related to the simple centroid-based classifier and compare the two methods empirically.

text: Naive Bayes for text classification with unbalanced classes Multinomial naive Bayes (MNB) is a popular method for document classification due to its computational efficiency and relatively good predictive performance. It has recently been established that predictive performance can be improved further by appropriate data transformations [1,2]. In this paper, we present another transformation that is designed to combat a potential problem with the application of MNB to unbalanced datasets. We propose an appropriate correction by adjusting attribute priors. This correction can be implemented as another data normalization step, and we show that it can significantly improve the area under the ROC curve. We also show that the modified version of MNB is very closely related to the simple centroid-based classifier and compare the two methods empirically.

year: 2006-01-01

title: The cold chain in New Zealand - A review

authors: Carson, James K.

subjects: Science & Technology

abstract: Approximately 45 % of all exports from New Zealand are food products or by-products, and an estimated 60 % of these are exported in the refrigerated state. The leading food sectors in terms of volume and income are in order: the dairy industry, the red meat industry, the horticultural industry and the seafood industry. Due to its geographic isolation, New Zealand food exports form part of some of the longest cold chains in the world. Responsibility for temperature integrity in the cold chain is placed on the processors and exporters and is overseen by the Ministry for Primary Industry of the Government of New Zealand. Currently, the major research theme related to the cold-chain in New Zealand is focussed around optimising chilling and freezing processes for shelf-life extension. Improving energy efficiency in refrigeration processes is also a significant research theme.

text: The cold chain in New Zealand - A review Approximately 45 % of all exports from New Zealand are food products or by-products, and an estimated 60 % of these are exported in the refrigerated state. The leading food sectors in terms of volume and income are in order: the dairy industry, the red meat industry, the horticultural industry and the seafood industry. Due to its geographic isolation, New Zealand food exports form part of some of the longest cold chains in the world. Responsibility for temperature integrity in the cold chain is placed on the processors and exporters and is overseen by the Ministry for Primary Industry of the Government of New Zealand. Currently, the major research theme related to the cold-chain in New Zealand is focussed around optimising chilling and freezing processes for shelf-life extension. Improving energy efficiency in refrigeration processes is also a significant research theme.

year: 2018

title: Mining at Te Aroha before the murder in February 1881

authors: Hart, Philip

abstract: Mining was slow to restart after the Christmas holidays on a goldfield whose value was still unknown. Some miners did not return, but other men, mostly with mining experience, replaced them. As was pointed out, more testing was required to justify the cautious optimism, and more explorations did not discover any payable ore or a reef of any sort. More capital was needed to fund adequate development, and the lack of a battery held back the field.
Some searched the nearby countryside, fruitlessly, but at Tui the mostly Maori miners working there seemed to be having better results. Unskilled miners who drove incompetent and even dangerous adits wasted their efforts, while others were accused of shepherding their ground. Two companies formed during January attracted many small investors, but experienced miners started leaving for newer finds, and non-miners abandoned their attempts at mining after discovering that gold was not easy to find. But others remained hopeful, and waited for the erection of a local battery to prove the value of what they had found.

text: Mining at Te Aroha before the murder in February 1881 Mining was slow to restart after the Christmas holidays on a goldfield whose value was still unknown. Some miners did not return, but other men, mostly with mining experience, replaced them. As was pointed out, more testing was required to justify the cautious optimism, and more explorations did not discover any payable ore or a reef of any sort. More capital was needed to fund adequate development, and the lack of a battery held back the field.
Some searched the nearby countryside, fruitlessly, but at Tui the mostly Maori miners working there seemed to be having better results. Unskilled miners who drove incompetent and even dangerous adits wasted their efforts, while others were accused of shepherding their ground. Two companies formed during January attracted many small investors, but experienced miners started leaving for newer finds, and non-miners abandoned their attempts at mining after discovering that gold was not easy to find. But others remained hopeful, and waited for the erection of a local battery to prove the value of what they had found.

year: 2016