Load profiling and data mining techniques in electricity deregulated market

This paper presents load profiles of electricity customers, using the knowledge discovery in databases (KDD) procedure, a data mining technique, to determine the load profiles for different types of customers. In this paper, the current load profiling methods are compared using data mining techniques, by analysing and evaluating these classification techniques. The objective of this study is to determine the best load profiling methods and data mining techniques to classify, detect and predict non-technical losses in the distribution sector, due to faulty metering and billing errors, as well as to gather knowledge on customer behaviour and preferences so as to gain a competitive advantage in the deregulated market. This paper focuses mainly on the comparative analysis of the classification techniques selected; a forthcoming paper will focus on the detection and prediction methods.

Co-registration of magnetoencephalography with magnetic resonance imaging using bite-bar-based fiducials and surface-matching

Objective: To introduce a new technique for co-registration of Magnetoencephalography (MEG) with magnetic resonance imaging (MRI). We compare the accuracy of a new bite-bar with fixed fiducials to a previous technique whereby fiducial coils were attached proximal to landmarks on the skull. Methods: A bite-bar with fixed fiducial coils is used to determine the position of the head in the MEG co-ordinate system. Co-registration is performed by a surface-matching technique. The advantage of fixing the coils is that the co-ordinate system is not based upon arbitrary and operator dependent fiducial points that are attached to landmarks (e.g. nasion and the preauricular points), but rather on those that are permanently fixed in relation to the skull. Results: As a consequence of minimizing coil movement during digitization, errors in localization of the coils are significantly reduced, as shown by a randomization test. Displacement of the bite-bar caused by removal and repositioning between MEG recordings is minimal (∼0.5 mm), and dipole localization accuracy of a somatosensory mapping paradigm shows a repeatability of ∼5 mm. The overall accuracy of the new procedure is greatly improved compared to the previous technique. Conclusions: The test-retest reliability and accuracy of target localization with the new design is superior to techniques that incorporate anatomical-based fiducial points or coils placed on the circumference of the head. © 2003 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Depth propagation and surface construction in 3-D vision

In stereo vision, regions with ambiguous or unspecified disparity can acquire perceived depth from unambiguous regions. This has been called stereo capture, depth interpolation or surface completion. We studied some striking induced depth effects suggesting that depth interpolation and surface completion are distinct stages of visual processing. An inducing texture (2-D Gaussian noise) had sinusoidal modulation of disparity, creating a smooth horizontal corrugation. The central region of this surface was replaced by various test patterns whose perceived corrugation was measured. When the test image was horizontal 1-D noise, shown to one eye or to both eyes without disparity, it appeared corrugated in much the same way as the disparity-modulated (DM) flanking regions. But when the test image was 2-D noise, or vertical 1-D noise, little or no depth was induced. This suggests that horizontal orientation was a key factor. For a horizontal sine-wave luminance grating, strong depth was induced, but for a square-wave grating, depth was induced only when its edges were aligned with the peaks and troughs of the DM flanking surface. These and related results suggest that disparity (or local depth) propagates along horizontal 1-D features, and then a 3-D surface is constructed from the depth samples acquired. The shape of the constructed surface can be different from the inducer, and so surface construction appears to operate on the results of a more local depth propagation process.

Depth propagation and surface construction in 3-D vision

Motion discontinuities can signal object boundaries where few or no other cues, such as luminance, colour, or texture, are available. Hence, motion-defined contours are an ecologically important counterpart to luminance contours. We developed a novel motion-defined Gabor stimulus to investigate the nature of neural operators analysing visual motion fields in order to draw parallels with known luminance operators. Luminance-defined Gabors have been successfully used to discern the spatial-extent and spatial-frequency specificity of possible visual contour detectors. We now extend these studies into the motion domain. We define a stimulus using limited-lifetime moving dots whose velocity is described over 2-D space by a Gabor pattern surrounded by randomly moving dots. Participants were asked to determine whether the orientation of the Gabor pattern (and hence of the motion contours) was vertical or horizontal in a 2AFC task, and the proportion of correct responses was recorded. We found that with practice participants became highly proficient at this task, able in certain cases to reach 90% accuracy with only 12 limited-lifetime dots. However, for both practised and novice participants we found that the ability to detect a single boundary saturates with the size of the Gaussian envelope of the Gabor at approximately 5 deg full-width at half-height. At this optimal size we then varied spatial frequency and found the optimum was at the lowest measured spatial frequency (0.1 cycle deg-1 ) and then steadily decreased with higher spatial frequencies, suggesting that motion contour detectors may be specifically tuned to a single, isolated edge.

Hydrophobicity and surface electrostatic charge of conidia of the mycoparasite Coniothyrium minitans

The effect of increasing culture age on cell surface hydrophobicity (CSH) and cell surface electrostatic charge (measured as zeta potential) of conidia from five isolates of Coniothyrium minitans representing three different morphological types was examined. Conidial CSH of three isolates (A2 960/1, CH1 and CH2) decreased with culture age, whereas CSH of two others (B 1300/2 and IMI 134523) remained high for the whole 42 day experimental period. In contrast, cell surface electrostatic charge decreased uniformly in conidia of all five isolates for the first 34 d and then rose slightly at 42 d. The variation in cell surface electrostatic charge (spectrum width) of the sampled conidia decreased with age for all five isolates. In all five isolates cell surface electrostatic charge of conidia became increasingly negative as the pH of the buffer used to suspend conidia was increased from pH 3.0 to 9.0. No relationship between colony morphology of C. minitans and conidial CSH and cell surface electrostatic charge was found.

Protein deposition at polymer surfaces:the bulk and surface structure-property effects of hydrogels

The primary objective of this research has been to investigate the interfacial phenomenon of protein adsorption in relation to the bulk and surface structure-property effect s of hydrogel polymers. In order to achieve this it was first necessary to characterise the bulk and surface properties of the hydrogels, with regard to the structural chemistry of their component monomers. The bulk properties of the hydrogels were established using equilibrium water content measurements, together with water-binding studies by differential scanning calorimetry (D.S.C.). Hamilton and captive air bubble-contact angle techniques were employed to characterise the hydrogel-water interface and from which by a mathematical derivation, the interfacial free energy (ðsw) and the surface free energy components (ð psv, ðdsv, ðsv) were obtained. From the adsorption studies using the radio labelled iodinated (125I) proteins of human serum albumin (H.S.A.) and human fibrinogen (H.Fb.), it was Found that multi-layered adsorption was occurring and that the rate and type of this adsorption was dependent on the physico-chemical behaviour of the adsorbing protein (and its bulk concentration in solution), together with the surface energetics of the adsorbent polymer. A potential method for the invitro evaluation of a material's 'biocompatibility' was also investigated, based on an empirically observed relationship between the adsorption of albumin and fibrinogen and the 'biocompatibility' of polymeric materials. Furthermore, some consideration was also given to the biocompatibility problem of proteinaceous deposit formation on hydrophilic soft' contact lenses and in addition a number of potential continual wear contact lens formulations now undergoing clinical trials,were characterised by the above techniques.

Characterisation and surface-profiling techniques for composite particles produced by dry powder coating in pharmaceutical drug delivery

The production of composite particles using dry powder coating is a one-step, environmentally friendly, process for the fabrication of particles with targeted properties and favourable functionalities. Diverse functionalities, such flowability enhancement, content uniformity, and dissolution, can be developed from dry particle coating. In this review, we discuss the particle functionalities that can be tailored and the selection of characterisation techniques relevant to understanding their molecular basis. We address key features in the powder blend sampling process and explore the relevant characterisation techniques, focussing on the functionality delivered by dry coating and on surface profiling that explores the dynamics and surface characteristics of the composite blends. Dry particle coating is a solvent- and heat-free process that can be used to develop functionalised particles. However, assessment of the resultant functionality requires careful selection of sensitive analytical techniques that can distinguish particle surface changes within nano and/or micrometre ranges.

The effect of care solutions on the bulk and surface properties of soft contact lenses

Purpose: Soft contact lenses for continuous wear require the use of cleaning regimes which utilise hydrogen peroxide systems or multipurpose cleaning solutions (MPS). The compositions of MPS are becoming increasingly complex and often include disinfectants, cleaning agents, preservatives, wetting agents, demulcents, chelating and buffering agents. Recent research on solution–lens interactions has focused on specific ocular parameters such as corneal staining. However the effect of a solution on the lens, particularly silicone hydrogel lenses, itself has received less attention. The purpose of this work was to establish and understand the effects that care solutions have on selected bulk and surface material properties. Methods: Selected bulk and surface properties of each material (etafilcon A, vifilcon A, balafilcon A, senofilcon A, lotrafilcon A and lotrafilcon B, galyfilcon A) were measured after a 24 h soak in a variety of care solutions. Additionally the lenses were soaked for 24 h in hyperosmolar (680 mOsm L-1) and hyposmolar (170 mOsm L-1) PBS. A bulk property parameter the total diameter (TD) was measured using an Optimec contact lens analyser. The surface property related CoF of soaked lenses was measured on a nano-tribometer with conditions of load 30 mN, at a distance of 20 mm and speed 30 mm/min. Results: In terms of bulk properties, change is related to the EWC of the lens, the higher the EWC of the lens the greater the TD changes. Silicone hydrogel lenses have EWCs of <47% and little or no TD changes were observed; lotrafilcon A exhibited no change irrespective of the cleaning solution. Conventional contact lenses have higher EWCs (58% for etafilcon A and 55% for vifilcon A) and the TD was seen to change to a greater extent, for example the etafilcon A material in ReNu MPS had an increase to 14.45± 0.07 mm from the cited 14.2 mm. Other lenses increased or decreased in TD depending on the solution used. The osmolarity of the solution although important is not the only factor governing change in the TD, for example soaking senofilcon A in hyperosmolar PBS (680 mOsm L-1) for 24 h increased the TD of the lens (+0.25 ± 0.07 mm), however when the same lens type was soaked for 24 h in a MPS with a lower osmolarity there was a similar effect. Biotribology measurements demonstrated that some solution–lens combinations can reduce the CoF by 55%, when compared with biotribology with the native packing solution. An increase in the CoF was observed for other solution–lens combinations. Conclusions: There is a dramatic difference in bulk and surface performance of specific lens materials with particular care solutions. Individual components of the care solutions have effects on the bulk and surface properties of contact lenses. The affects are not as great with the silicone hydrogel as compared with conventional hydrogels.

Bulk and surface switching in Mn-Fe-based Prussian blue analogues

Many Prussian Blue Analogues are known to show a thermally induced phase transition close to room temperature and a reversible, photo-induced phase transition at low temperatures. This work reports on magnetic measurements, X-ray photoemission and Raman spectroscopy on a particular class of these molecular heterobimetallic systems, specifically on Rb0.81Mn[Fe(CN)6]0.95_1.24H2O, Rb0.97Mn[Fe(CN)6]0.98_1.03H2O and Rb0.70Cu0.22Mn0.78[Fe(CN)6]0.86_2.05H2O, to investigate these transition phenomena both in the bulk of the material and at the sample surface. Results indicate a high degree of charge transfer in the bulk, while a substantially reduced conversion is found at the sample surface, even in case of a near perfect (Rb:Mn:Fe=1:1:1) stoichiometry. Thus, the intrinsic incompleteness of the charge transfer transition in these materials is found to be primarily due to surface reconstruction. Substitution of a large fraction of charge transfer active Mn ions by charge transfer inactive Cu ions leads to a proportional conversion reduction with respect to the maximum conversion that is still stoichiometrically possible and shows the charge transfer capability of metal centers to be quite robust upon inclusion of a neighboring impurity. Additionally, a 532 nm photo-induced metastable state, reminiscent of the high temperature Fe(III)Mn(II) ground state, is found at temperatures 50-100 K. The efficiency of photo-excitation to the metastable state is found to be maximized around 90 K. The photo-induced state is observed to relax to the low temperature Fe(II)Mn(III) ground state at a temperature of approximately 123 K.

Applications of Nonclassical Logic Methods for Purposes of Knowledge Discovery and Data Mining

* The work is partially supported by Grant no. NIP917 of the Ministry of Science and Education – Republic of Bulgaria.

Polymer-lipid interactions:biomimetic self-assembly behaviour and surface properties of poly(styrene-alt-maleic acid) with diacylphosphatidylcholines

Abstract Various lubricating body fluids at tissue interfaces are composed mainly of combinations of phospholipids and amphipathic apoproteins. The challenge in producing synthetic replacements for them is not replacing the phospholipid, which is readily available in synthetic form, but replacing the apoprotein component, more specifically, its unique biophysical properties rather than its chemistry. The potential of amphiphilic reactive hypercoiling behaviour of poly(styrene-alt-maleic acid) (PSMA) was studied in combination with two diacylphosphatidylcholines (PC) of different chain lengths in aqueous solution. The surface properties of the mixtures were characterized by conventional Langmuir-Wilhelmy balance (surface pressure under compression) and the du Noüy tensiometer (surface tension of the non-compressed mixtures). Surface tension values and 31P NMR demonstrated that self-assembly of polymer-phospholipid mixtures were pH and concentration-dependent. Finally, the particle size and zeta potential measurements of this self-assembly showed that it can form negatively charged nanosized structures that might find use as drug or lipids release systems on interfaces such as the tear film or lung interfacial layers. The structural reorganization was sensitive to the alkyl chain length of the PC.

Analysis and Data Mining of Lead-Zinc Ore Data

This paper presents the results of our data mining study of Pb-Zn (lead-zinc) ore assay records from a mine enterprise in Bulgaria. We examined the dataset, cleaned outliers, visualized the data, and created dataset statistics. A Pb-Zn cluster data mining model was created for segmentation and prediction of Pb-Zn ore assay data. The Pb-Zn cluster data model consists of five clusters and DMX queries. We analyzed the Pb-Zn cluster content, size, structure, and characteristics. The set of the DMX queries allows for browsing and managing the clusters, as well as predicting ore assay records. A testing and validation of the Pb-Zn cluster data mining model was developed in order to show its reasonable accuracy before beingused in a production environment. The Pb-Zn cluster data mining model can be used for changes of the mine grinding and floatation processing parameters in almost real-time, which is important for the efficiency of the Pb-Zn ore beneficiation process. ACM Computing Classification System (1998): H.2.8, H.3.3.

A Taxonomy of Big Data for Optimal Predictive Machine Learning and Data Mining

Big data comes in various ways, types, shapes, forms and sizes. Indeed, almost all areas of science, technology, medicine, public health, economics, business, linguistics and social science are bombarded by ever increasing flows of data begging to be analyzed efficiently and effectively. In this paper, we propose a rough idea of a possible taxonomy of big data, along with some of the most commonly used tools for handling each particular category of bigness. The dimensionality p of the input space and the sample size n are usually the main ingredients in the characterization of data bigness. The specific statistical machine learning technique used to handle a particular big data set will depend on which category it falls in within the bigness taxonomy. Large p small n data sets for instance require a different set of tools from the large n small p variety. Among other tools, we discuss Preprocessing, Standardization, Imputation, Projection, Regularization, Penalization, Compression, Reduction, Selection, Kernelization, Hybridization, Parallelization, Aggregation, Randomization, Replication, Sequentialization. Indeed, it is important to emphasize right away that the so-called no free lunch theorem applies here, in the sense that there is no universally superior method that outperforms all other methods on all categories of bigness. It is also important to stress the fact that simplicity in the sense of Ockham’s razor non-plurality principle of parsimony tends to reign supreme when it comes to massive data. We conclude with a comparison of the predictive performance of some of the most commonly used methods on a few data sets.