Le Cam meets LeCun: Deficiency and Generic Feature Learning

"Deep Learning" methods attempt to learn generic features in an unsupervised fashion from a large unlabelled data set. These generic features should perform as well as the best hand crafted features for any learning problem that makes use of this data. We provide a definition of generic features, characterize when it is possible to learn them and provide methods closely related to the autoencoder and deep belief network of deep learning. In order to do so we use the notion of deficiency and illustrate its value in studying certain general learning problems.Comment: 25 pages, 2 figure

Learning with Symmetric Label Noise: The Importance of Being Unhinged

Convex potential minimisation is the de facto approach to binary classification. However, Long and Servedio [2010] proved that under symmetric label noise (SLN), minimisation of any convex potential over a linear function class can result in classification performance equivalent to random guessing. This ostensibly shows that convex losses are not SLN-robust. In this paper, we propose a convex, classification-calibrated loss and prove that it is SLN-robust. The loss avoids the Long and Servedio [2010] result by virtue of being negatively unbounded. The loss is a modification of the hinge loss, where one does not clamp at zero; hence, we call it the unhinged loss. We show that the optimal unhinged solution is equivalent to that of a strongly regularised SVM, and is the limiting solution for any convex potential; this implies that strong l2 regularisation makes most standard learners SLN-robust. Experiments confirm the SLN-robustness of the unhinged loss

Evaluation of the Nietvoorbi j Wine Score Card and Experimental Wine Panelists Utilizing Pattern Recognition Techniques

Principal component analysis (PCA) was applied to four cultivar wines, submitted repetitively amongst more than 450 experimental wines, to a sensory evaluation panel of 18 members who used a scoring system comprising overall wine quality and 11 wine descriptors. Inconsistent judges could be eliminated by the evaluation of scatter diagrams. After eliminating 11 judges, the scores of the remaining 7 were used to evaluate the score card in terms of weights placed on individual descriptors in a multiple regression equation, which related the 11 parameters to overall quality scores. Deviations from actual score card weights are discussed in terms of previous PCA analyses, and it is argued that both cultivar and the composition of a mixed data set with respect to these factors, could affect the relative importance of certain parameters. Fitting a similar equation to a large data set consisting of about 480 wines, comprising 23 different cultivars, confirmed the need for further investigations concerning relative score card weights, as well as a critical evaluation of score card parameters for evaluating widely diverging experimental wines

Studies in virus diseases

In any approach to this subject it is essential first to review the relevant literature, and secondly to examine and discuss the physical, chemical and physico-chemical principles upon which instruments such as the ultra violet light, electron, and fluorescence microscopes are constructed. Only in this way can one interpret the significance of published research and correlate them with one's own deductions.The following pages contain a comprehensive description of apparatus used, their mode of operation, scope of usefulness and methods of interpreting data. The text is subdivided into sections dealing with rnicroscopy, staining , filtration and centrifugation, in which are contained personal observations on the morphology of the elementary bodies of myxoma and their centrifugalisation, also an account of the existence of elementary bodies in Rift Valley fever

The Effect of Fermentation Time (as Induced by Fermentation and Must Conditions) on the Chemical Profile and Quality of a Chenin blanc Wine

Pattern recognition and simple factorial analyses were applied to chemical profiles determined on wines resulting from an experiment in which the effect of grape solids, assimilable nitrogen, bentonite and fermentation temperaturelevels as well as culture aeration on total fermentation time was investigated. It was found that fermentation times of the untreated Chenin blanc must could be shortened considerably by increasing grape solid levels and/ or nitrogen as well as temperature. However, it was established that the speeding up of fermentation at sub-optimal assimilable nitrogen levels leads to wines relatively high in higher alcohols and low in esters

Grape Maturity and Wine Quality

Several indices calculated from grape juice analyses were submitted to statistical analyses in order to determine correlations of these indices with quality of wine made from grapes at different stages of maturity. Curvilinear relationships were obtained enabling an optimum point to be calculated relating grape maturity to maximum wine quality. The application of skin contact in the case of white wine cultivars resulted in earlier maxima for wine quality, thus compensating to an extent for earlier harvesting. The cultivars Chenin blanc, Colombar, Pinotage and Cabernet Sauvignon were examined as outlined above over several years

How cheap is primary health care? Cost per script at the Heidedal Community Health Centre and National District Hospital in Bloemfontein

Background: It is essential to manage and budget for primary health care in order to deliver a sustainable, accessible and quality health service to the majority of the population. The aim of the study was to establish the cost per script at the Heidedal Community Health Centre (HCHC) and at the National District Hospital (NDH) in Bloemfontein and to evaluate prescribing patterns, the protocols and use of the Essential Drug List (EDL) and Standard Treatment Guidelines (STGs) and to budget more accurately for medicine. Methods: During a two-month period, every fifth script dispensed at HCHC and NDH was included in the study and analysed until we had included 1 000 scripts from each facility. Results: The mean number of items per script at the CHC was 3.3 and at the DH was 4.1, and the mean cost was R14.66 versus R64.69 respectively. At HCHC, 62 025 prescriptions were dispensed and at NDH 56 312 were dispensed at an estimated total value of R4.5 million during 2002. Conclusion: Many problem areas and incorrect prescribing patterns were identified and need to be addressed. Although the cost per script at primary care level is not high, the number of patients that need treatment is enormous. Primary health care is actually very expensive and good quality control is necessary.South African Family Practice Vol. 47(7) 2005: 37-4