Frequency and voltage partitioning in presence of renewable energy resources for power system (example: North Chile power network)

This paper investigates techniques for frequency and voltage partitioning of power network based on the graph-theory. These methods divide the power system into distinguished regions to avoid the spread of disturbances and to minimize the interaction between these regions for frequency and voltage control of power system. In case of required active and reactive power for improving the performance of the power system, control can be performed regionally instead of a centralized controller. In this paper, renewable energy sources are connected to the power network to verify the effect of these sources on the power systems partitioning and performance. The number of regions is found based on the frequency sensitivity for frequency partitioning and bus voltage for voltage partitioning to disturbances being applied to loads in each region. The methodology is applied to the north part of Chile power network. The results show the performance and ability of graph frequency and voltage partitioning algorithm to divide large scale power systems to smaller regions for applying decentralized controllers.Peer ReviewedPostprint (published version

A generic tool to assess impact of changing edit rules in a business survey - an application to the UK Annual Business Inquiry part 2

Business surveys often use complex sets of edit rules (edits, for short) to check returned questionnaires (records), locate suspicious or unacceptable responses, and support data cleaning operations prior to using the survey responses for estimation of the required target parameters. These sets of edits are complex because they may involve large numbers of survey questionnaires and variables, they may contain a large number of edits, and the edits may depend on a large number of tolerance parameters. When such sets of edits are used, they may cause large numbers of record failures and generate substantial costs of revision, especially if edit failures are dealt with by means of clerical operations, like reviewing original paper questionnaires or digital images of these, and re-contacting businesses for clarification and/or correction of the responses provided. Costs can be high both in terms of the resources required, as well as in terms of timeliness of survey processing, by delaying availability of the survey data for estimation and publication.In this paper we describe a generic tool, developed as a result of the collaboration between the University of Southampton and the ONS. This tool can help to assess the potential impact of changing the edits in a specified business survey. It is a SAS macro using the IML language which enables calculation of a number of edit performance and data quality indicators. Changes to the set of edits aiming to ‘relax’ the existing edits so that failure rates decrease and efficiency savings are achieved are assessed by means of several edit-related performance indicators, like failure and hit rates, false hit rates, etc.. Data quality indicators include proportion of errors missed and estimates of the bias resulting from missing errors for a specified revision of the set of edits. Edit designers and managers can then aim to fine tune their edits so that failure rates, false hit rates and editing costs are reduced, while data quality is preserved. An illustration is provided by the application of the tool to revise the edits used for the UK Annual Business Inquiry Part 2 to the reference year 2007

Transitions between dissipative localized structures in the simplified Gilad-Meron model for dryland plant ecology

Spatially extended patterns and multistability of possible different states is common in many ecosystems, and their combination has an important impact on their dynamical behaviours. One potential combination involves tristability between a patterned state and two different uniform states. Using a simplified version of the Gilad-Meron model for dryland ecosystems, we study the organization, in bifurcation terms, of the localized structures arising in tristable regimes. These states are generally related with the concept of wave front locking, and appear in the form of spots and gaps of vegetation. We find that the coexistence of localized spots and gaps, within tristable configurations, yield the appearance of hybrid states. We also study the emergence of spatiotemporal localized states consisting in a portion of a periodic pattern embedded in a uniform Hopf-like oscillatory background in a subcritical Turing-Hopf dynamical regime

Endemic Methicillin-Resistant Staphylococcus Aureus: Nurses' Risk Perceptions and Attitudes

Dissemination of methicillin-resistant Staphylococcus aureus (MRSA) remains one of the most difficult challenges for prevention, control, and treatment of health care-associated infections. A survey and interviews were conducted on nurses from a hospital center. We found that most nurses' perceived risk of acquiring MRSA related to themselves (72%), other nurses (88.5%), and patients (97.8%). This perception influences attitudes, leading to compliance with the existing recommendations

Ising Field Theory on a Pseudosphere

We show how the symmetries of the Ising field theory on a pseudosphere can be exploited to derive the form factors of the spin fields as well as the non-linear differential equations satisfied by the corresponding two-point correlation functions. The latter are studied in detail and, in particular, we present a solution to the so-called connection problem relating two of the singular points of the associated Painleve VI equation. A brief discussion of the thermodynamic properties is also presented.Comment: 39 pages, 6 eps figures, uses harvma

Sentiment Analysis for e-Payment Service Providers Using Evolutionary eXtreme Gradient Boosting

Online services depend primarily on customer feedback and communications. When this kind of input is lacking, the overall approach of the service provider can shift in unintended ways. These services rely on feedback to maintain consumer satisfaction. Online social networks are a rich source of consumer data related to services and products. Well developed methods like sentiment analysis can offer insightful analyses and aid service providers in predicting outcomes based on their reviews—which, in turn, enables decision-makers to develop effective strategic plans. However, gathering this data is more challenging on Arabic online social networks, due to the complexity of the Arabic language and its dialects. In this study, we propose an approach to sentiment analysis that combines a neutrality detector model with eXtreme Gradient Boosting and a genetic algorithm to effectively predict and analyze customers’ opinions of an e-Payment service through an Arabic social network. The proposed approach yields excellent results compared to other approaches. Feature analysis is also conducted on consumer reviews to identify influencing keywords.Deanship of Scientific Research, The University of JordanMinisterio espanol de Economia y Competitividad TIN2017-85727-C4-2-

Capturing the industrial requirements of set-based design for CONGA framework

The Configuration Optimisation of Next-Generation Aircraft (CONGA) is a proposed framework in a response industrial need to enhance the aerospace capability in the UK. In order to successfully address this challenge, a need to develop a true multi-disciplinary Set-Based Design (SBD) capability that could deploy new technologies on novel configurations more quickly and with greater confidence was identified. This paper presents the first step towards the development of the SBD capabilities which is to elicit the industrial requirement of the SBD process for the key aerospace industrial partners involved in this CONGA approach

Robot skills and cognitive performance of preschool children

Several studies have demonstrated the potential of robots as assistive tools for play activities. Through the use of robots, children with motor impairments may be able to manipulate objects and engage in play activities as their typically developing peers, thus having the same opportunities to learn cognitive, social, motor and linguistic skills. Robot use can also provide a proxy measure of disabled children's cognitive abilities by comparing their performance with that of typically developing children. This paper reports a study with eighteen typically developing children aged three, four and five years to assess at which ages the cognitive concepts of causality, negation, binary logic, and sequencing are demonstrated during Lego robot use.info:eu-repo/semantics/acceptedVersio