EnsembleSVM: A Library for Ensemble Learning Using Support Vector Machines

EnsembleSVM is a free software package containing efficient routines to perform ensemble learning with support vector machine (SVM) base models. It currently offers ensemble methods based on binary SVM models. Our implementation avoids duplicate storage and evaluation of support vectors which are shared between constituent models. Experimental results show that using ensemble approaches can drastically reduce training complexity while maintaining high predictive accuracy. The EnsembleSVM software package is freely available online at http://esat.kuleuven.be/stadius/ensemblesvm.Comment: 5 pages, 1 tabl

Scalable Multi-label Classification

Multi-label classification is relevant to many domains, such as text, image and other media, and bioinformatics. Researchers have already noticed that in multi-label data, correlations exist between labels, and a variety of approaches, drawing inspiration from many spheres of machine learning, have been able to model these correlations. However, data sources from the real world are growing ever larger and the multi-label task is particularly sensitive to this due to the complexity associated with multiple labels and the correlations between them. Consequently, many methods do not scale up to large problems. This thesis deals with scalable multi-label classification: methods which exhibit high predictive performance, but are also able to scale up to larger problems. The first major contribution is the pruned sets method, which is able to model label correlations directly for high predictive performance, but reduces overfitting and complexity over related methods by pruning and subsampling label sets, and can thus scale up to larger datasets. The second major contribution is the classifier chains method, which models correlations with a chain of binary classifiers. The use of binary models allows for scalability to even larger datasets. Pruned sets and classifier chains are robust with respect to both the variety and scale of data that they can deal with, and can be incorporated into other methods. In an ensemble scheme, these methods are able to compete with state-of-the-art methods in terms of predictive performance as well as scale up to large datasets of hundreds of thousands of training examples. This thesis also puts a special emphasis on multi-label evaluation; introducing a new evaluation measure and studying threshold calibration. With one of the largest and most varied collections of multi-label datasets in the literature, extensive experimental evaluation shows the advantage of these methods, both in terms of predictive performance, and computational efficiency and scalability

High-efficiency chrome tanning using pre-treatments

Content: Pre-treatments are widely used during tanning processes as to improve the performance of the main tannage. Synchrotron small-angle X-ray scattering (SAXS) and differential scanning calorimetry (DSC) were used to study four common types of pre-treatments, viz. monodentate complexing agent (sodium formate, SF), chelating agent (disodium phthalate, DSP), covalent cross-linker (glutaraldehyde, GA) and nanoclay (sodium montmorillonite, MMT) about their effects on chromium-collagen cross-linking reaction during tanning. Based on the results, the performance of chromium-collagen cross-linking with and without pre-treatments was presented considering five aspects: cross-linking, the level of hydration, hydrothermal stability, uniformity through leather cross-section and the uptake of chrome. Comparing to the original ThruBlu chrome tanning, at the same chrome offers, leather pre-treated using SF, DSP and MMT showed improved hydrothermal stability, uniformity and the level of hydration, while GA showed decreased hydration. All of the pre-treatments reduce surface fixation by decreasing the reactivity of chromium with collagen. Changes in the reaction performance can influence the properties of the leather products as well as the efficiency of the leather manufacturing processes. Insights into the structural changes of collagen during tanning with varied reaction conditions can guide the design of novel, benign tanning processes to reduce environmental impact. Take-Away: 1. Uniformity of the hydrothermal stability through leather cross-section were improved by all of the studied pre-treatments. 2. Reactivity of chromium to cross-link with collagen was reduced as a result of the complexing, covalent cross-linking, or preferential adsorption. 3. Complexing agents and nanoclay pre-treatments tend to retain collagen bound water, while covalent cross-linker causing decrease in the level of hydration of collagen

Towards a molecular level understanding of chrome tanning: Interplay between collagen structure and reactivity

Content: Synchrotron small-angle X-ray scattering (SAXS) technique was applied to leather research to understand the changes in molecular-level collagen structure during tanning and denaturation (shrinkage), which can help reduce the environmental impact from the extensive chrome usage. Based on SAXS results from realtime denaturation experiments on leather samples, we established a mechanistic model of chrome tanning indicated by the structural changes of collagen. It suggests that only a low level of chromium species is effectively involved in the cross-linking with collagen, which highlights the overuse of chrome during conventional tanning processes. Any extra amount of chrome added, however, can support the stabilisation of collagen possibly via a non-covalent mechanism. Such mechanism points towards a more environment-friendly tanning method by using suitable supplementary reagents to benefit tanning effect non-covalently instead of chrome. By pre-treating with complexing agents such as sodium formate and disodium phthalate, as well as nanoclay (sodium montmorillonite), the uniformity through bovine hide collagen matrix were improved significantly. These pre-treatments effectively reduce the reactivity of chromium during its cross-linking reaction with collagen while retaining its bound water. However, collagen pre-treated with a covalent cross-linker (glutaraldehyde) results in a decrease in both chromium-collagen cross-linking and bound water while improving uniformity. These molecular-level insights can be developed into metrics to guide us towards a more sustainable future for the leather industry. The coating on collagen fibrils can provide a pseudo-stabilisation effect of increasing the heat resistance of collagen. A group of tanning experiments were also conducted in situ on the SAXS beamline to observe the different mechanisms of free-of-chrome alternative tannages as potential replacements. Overall, synchrotron SAXS provides valuable information about collagen structure changes that could lead to more efficient use of chrome (or other tanning agents) in the global leather tanning industry. Take-Away: 1. Kinetics of hydrothermal denaturation and collagen crosslinking mechanism proceed through different pathways 2. Alternative chemistries to enhance chrome uptake at low offers. 3. The role of collagen structure studies in understanding tanning mechanim

Comparing the Measured and Thermodynamically Predicted AFm Phases in a Hydrating Cement

In hydrating Portland cements, more than one of the AFm family of calcium aluminates may exist. Depending on the amount of carbonate and sulfate present in the cement, the most common phase to precipitate is monosulfate, monocarbonate and/or hemicarbonate. It has been reported in the literature that hemicarbonate often appears in measurements such as XRD but not predicted to form/equilibrate in thermodynamic models. With the ongoing use of commercial cements such as CEM I and CEM II containing more and more limestone, it is important to understand which hydrate solids physically precipitate and numerically predict over time. Using 27 cement samples with three w/c ratios analysed at 1, 3 and 28 days, this paper shows that although hemicarbonate was observed in a hydrating commercial Portland cement, as well as being predicted based on its carbonate (CO2/Al2O3) and sulfate (SO3/Al2O3) ratios, thermodynamic analysis did not predict it to equilibrate and form as a solid hydrate. Regardless of the w/c ratio, thermodynamic analysis did predict hemicarbonate to form for calcite contents \u3c 2 wt.%. It appears that the dominant stability of monocarbonate in thermodynamic models leads to it precipitating and remaining as a persistent phase

GURLS: A Least Squares Library for Supervised Learning

We present GURLS, a least squares, modular, easy-to-extend software library for efficient supervised learning. GURLS is targeted to machine learning practitioners, as well as non- specialists. It offers a number state-of-the-art training strategies for medium and large-scale learning, and routines for efficient model selection. The library is particularly well suited for multi-output problems (multi-category/multi-label). GURLS is currently available in two independent implementations: Matlab and C++. It takes advantage of the favorable properties of regularized least squares algorithm to exploit advanced tools in linear algebra. Routines to handle computations with very large matrices by means of memory-mapped storage and distributed task execution are available. The package is distributed under the BSD license and is available for download at https://github.com/LCSL/GURLS

Application of multivariate analysis in the processing of medical data

Medical data frequently represent multidimensional datasets as investigated factors and clinical and laboratory parameters coverage is huge. This research area is very important in terms of practical applications. We were given monthly lipid metabolism and hormonal status data of children (including children suffering from obesity) of Siberian region during a year. In this article some research results appear

Audit of walk-in access for members of the public to online resources at higher education and further education libraries in the South West of England

This SWRLS-funded project aims to analyse and evaluate the extent to which Higher Education (HE) and Further Education (FE) libraries across the South West region of the United Kingdom provide walk-in access to electronic resources.The information presented within this report is derived from the findings of a survey questionnaire of librarians from across the South West region. Findings of the survey reveal that in the majority of the six institutions that provide walk-in access, the service is not actively promoted. Potential audiences are not actively identified. Information about walk-in services and which resources are available to use within HE or FE in the region is currently hard to discover. There does appear to be some desire to provide walk-in access but the report identifies IT difficulties and legal issues over licences as particular barriers to implementation

Stressful life-events exposure is associated with 17-year mortality, but it is health-related events that prove predictive

Objectives Despite the widely-held view that psychological stress is a major cause of poor health, few studies have examined the relationship between stressful life-events exposure and death. The present analyses examined the association between overall life-events stress load, health-related and health-unrelated stress, and subsequent all-cause mortality.\ud \ud Design This study employed a prospective longitudinal design incorporating time-varying covariates.\ud \ud Methods Participants were 968 Scottish men and women who were 56 years old. Stressful life-events experience for the preceding 2 years was assessed at baseline, 8–9 years and 12–13 years later. Mortality was tracked for the subsequent 17 years during which time 266 participants had died. Cox's regression models with time-varying covariates were applied. We adjusted for sex, occupational status, smoking, BMI, and systolic blood pressure.\ud \ud Results Overall life-events numbers and their impact scores at the time of exposure and the time of assessment were associated with 17-year mortality. Health-related event numbers and impact scores were strongly predictive of mortality. This was not the case for health-unrelated events.\ud \ud Conclusions The frequency of life-events and the stress load they imposed were associated with all-cause mortality. However, it was the experience and impact of health-related, not health-unrelated, events that proved predictive. This reinforces the need to disaggregate these two classes of exposures in studies of stress and health outcomes.\u