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Voltage dips are considered to be one of the costliest of all power quality disturbances due to their disruption of industrial and commercial operations. The ability to characterise the voltage dip performance of distribution networks has many benefits for industry. There is considerable potential for industry to make large economic gains if voltage dip behaviour can be better understood and planned for. To put strategies in place to deal with voltage dips, there is a need for extensive data collection and analysis so that correct planning decisions can be made. This study details the characteristics of voltage dip data which has been collected at low-voltage sites in Australia over a 9 year period. The data is displayed in a number of different formats to aid analysis. [ABSTRACT FROM AUTHOR]

Data perturbation aims to disguise original data values so the confidential information is kept safe and the disclosure risk is minimized. In this article, we exploit the characteristics of nonmetric multidimensional scaling (NMDS) to transform data and generate perturbed data. We hypothesize that NMDS is a good tool for privacy-preserving data clustering. For this, our model should preserve the distance between data objects (data utility in the context of clustering) whilst introducing enough uncertainty about the original data. We discuss privacy attacks in the context of disclosing the original data values and show that our method introduces uncertainty which could hinder the attacker from determining the exact location of points in the original space. We examine our model on a number of benchmark datasets and compare the results obtained from the perturbed data with those obtained from the original data using a number of clustering algorithms. We compare with other data perturbation techniques such as principal component analysis (PCA), random projection, single value decomposition and discrete cosine transform. We show that both NMDS and PCA produce the best utility preservation, obtaining clusterings of the perturbed data which are very similar to those on the original data. We also show that the transformation using NMDS introduces more uncertainty than other transformations in the point placement location and as the transformation is independent of the original data values it should produce enhanced privacy preservation. [ABSTRACT FROM AUTHOR]

The ITI curve developed by the Information Technology Industry Council (USA) describes an AC input voltage envelope, which typically can be tolerated by most information technology (IT) equipment supplied by nominal 120 V 60 Hz electricity networks. Although the curve ostensibly applies only to IT equipment supplied at 120 V 60 Hz it is often used throughout the electricity supply industry, including at other nominal voltages and frequencies, without modification or consideration of applicability to provide an indication of the input voltage tolerance of a wide range of equipment. This paper details a preliminary study aimed at developing an ITI style curve to suit 230 V 50 Hz electricity networks. A range of domestic and industrial equipment has been tested to determine voltage sag susceptibility. Overall, results for domestic appliances show that equipment connected to the Australian 230 V 50 Hz electricity network has voltage sag immunity considerably better than that defined by the ITI curve. The same may be said for the majority of industrial equipment tested. As such, the suitability of the ITI curve in describing a sag immunity envelope for individual pieces of equipment connected to 230 V 50 Hz electricity networks is highly questionable. [ABSTRACT FROM AUTHOR]

The author comments on the article "Garden Warbler (GW) Sylvia borin migration in sub-Saharan West Africa: phenology and body mass changes," by U. Ottosson and others. Ottosson and others note the lack of information from the sub-Saharan part of the migration range of the GWs. The author notes that data on GWs from West Africa, collected in the 1960s has not been mentioned. The author also comments on other issues including the mean weights, influence of climate change and flight models.