250 research outputs found
Definition of MV Load Diagrams via Weighted Evidence Accumulation Clustering using Subsampling
A definition of medium voltage (MV) load diagrams was made, based on the data base knowledge discovery process. Clustering techniques were used as support for the agents of the electric power retail markets to obtain specific knowledge of their customers’ consumption habits. Each customer class resulting from the clustering operation is represented by its load diagram. The Two-step clustering algorithm and the WEACS approach based on evidence accumulation (EAC) were applied to an electricity consumption data from a utility client’s database in order to form the customer’s classes and to find a set of representative consumption patterns.
The WEACS approach is a clustering ensemble combination approach that uses subsampling and that weights differently the partitions in the co-association matrix. As a complementary step to the WEACS approach, all the final data partitions produced by the different variations of the method are combined and the Ward Link algorithm is used to obtain the final data partition. Experiment results showed that WEACS approach led to better accuracy than many other clustering approaches. In this paper the WEACS approach separates better the customer’s population than Two-step clustering algorithm
Determination of electricity consumers’ load profiles via weighted evidence accumulation clustering using subsampling
With the electricity market liberalization, the distribution and retail companies are looking for better market strategies based on adequate information upon the consumption patterns of its electricity consumers. A fair
insight on the consumers’ behavior will permit the definition of specific contract aspects based on the different consumption patterns. In order to form the different consumers’ classes, and find a set of representative consumption patterns we use electricity consumption data from a utility client’s database and two approaches: Two-step clustering algorithm and the WEACS approach based on evidence accumulation (EAC) for combining partitions in a clustering ensemble. While EAC uses a voting mechanism to produce a co-association matrix based on the pairwise associations obtained from N partitions and where each partition has equal weight in the combination process, the WEACS approach uses subsampling and weights differently the partitions. As a complementary step to the WEACS approach, we combine the partitions obtained in the WEACS approach with the ALL clustering ensemble construction method and we use the Ward Link algorithm to obtain the final data partition. The characterization of the obtained consumers’ clusters was performed using the C5.0 classification algorithm. Experiment results showed that the WEACS approach leads to better results than many other clustering approaches
Recurrence of conduction in accessory atrioventricular connections after initially successful radiofrequency catheter ablation
AbstractThe purpose of this study was to characterize the incidence and clinical features of accessory pathway recurrence after initially successful radiofrequency catheter ablation and to identify variables correlated with recurrence. Radiofrequency ablation was performed with a 7F deflectable tip catheter with a large (4 mm in length) distal electrode. Left-sided accessory patthways were approached through the left ventricle and right-sided pathways by way of the right atrium. Patients were included in the study if 1) they had an initially successful procedure, defined as the absence of accessory pathway conduction immediately after ablation, and 2) had undergone a 3-month follow-up electrophysiologic test or had documented recurrence of accessory pathway conduction.Accessory pathway conduction recurred after initially successful ablation in 16 (12%) of 130 patients. Almost half (7 of 16) of these recurrences were in the 1st 12 h after ablation, and the last occurred after 106 days. Return of delta waves on the electrocardiogram (ECG) or spontaneous paroxysmal supraventricular tachycardia was the initial indication of recurrence in 15 of the 16 patients. Two patients with manifest accessory pathways exhibited recurrence with exclusively concealed accessory pathway conduction.Accessory pathways ablated from the tricuspid anulus (right free wall or septal accessory pathways) had a much higher recurrence rate (24%) than did those on the mitral anulus (6%). Fourteen of 15 patients have had successful repeat accessory pathway ablation after the initial recurrence. After a mean follow-up period of 4 ± 3 months, there have been no repeat recurrences of any of these accessory pathways.It is concluded that accessory pathway recurrence is infrequent after successful radiofrequency catheter ablation. All but one episode of recurrence was diagnosed clinically, suggesting that routine follow-up electrophysiologic testing in asymptomatic patients is not warranted. Because manifest accessory pathways may recur with retrograde conduction only, patients with palpitation after ablation should have electrophysiologic testing even if no delta waves are seen on the ECG. The success rate of ablation after recurrence (93%) is comparable to that achieved at the initial session, suggesting that return of accessory pathway function should not be a contraindication to a repeat attempt
Common bean SNP alleles and candidate genes affecting photosynthesis under contrasting water regimes
Water deficit is a major worldwide constraint to common bean (Phaseolus vulgaris L.) production, being
photosynthesis one of the most affected physiological processes. To gain insights into the genetic basis of the
photosynthetic response of common bean under water-limited conditions, a collection of 158 Portuguese accessions
was grown under both well-watered and water-deficit regimes. Leaf gas-exchange parameters were measured and
photosynthetic pigments quantified. The same collection was genotyped using SNP arrays, and SNP-trait associations
tested considering a linear mixed model accounting for the genetic relatedness among accessions. A total of 133 SNPtrait
associations were identified for net CO2 assimilation rate, transpiration rate, stomatal conductance, and
chlorophylls a and b, carotenes, and xanthophyll contents. Ninety of these associations were detected under waterdeficit
and 43 under well-watered conditions, with only two associations common to both treatments. Identified
candidate genes revealed that stomatal regulation, protein translocation across membranes, redox mechanisms,
hormone, and osmotic stress signaling were the most relevant processes involved in common bean response to
water-limited conditions. These candidates are now preferential targets for common bean water-deficit-tolerance
breeding. Additionally, new sources of water-deficit tolerance of Andean, Mesoamerican, and admixed origin were
detected as accessions valuable for breeding, and not yet exploredinfo:eu-repo/semantics/publishedVersio
AVALIAÇÃO DO TEOR DE UMIDADE DA MADEIRA DE Eucalyptus grandis POR MEDIDORES ELÉTRICOS RESISTIVOS
O presente estudo teve como objetivo verificar a precisão de dois tipos de medidores elétricos de teor de umidade durante o processo de secagem da madeira de Eucalyptus grandis. Foram retiradas amostras representativas de 14 tábuas de Eucalyptus grandis e secas em estufa elétrica a 40 ºC de temperatura, até que o material atingisse 10% de umidade. Durante a secagem foram determinados, periodicamente, o teor de umidade através do método de massas correntes e de verificações simultâneas com um medidor elétrico portátil (EMM) e com o sistema de controle de um secador convencional (KCS). Os resultados mostraram que: (1) o sensor de umidade KCS pode substituir o método gravimétrico durante a secagem da madeira; (2) o medidor do teor de umidade EMM subestima os reais teores de umidade durante a secagem da madeira e não é indicado para substituir o método gravimétrico de determinação de umidade
Foundations of Digital Arch{\ae}oludology
Digital Archaeoludology (DAL) is a new field of study involving the analysis
and reconstruction of ancient games from incomplete descriptions and
archaeological evidence using modern computational techniques. The aim is to
provide digital tools and methods to help game historians and other researchers
better understand traditional games, their development throughout recorded
human history, and their relationship to the development of human culture and
mathematical knowledge. This work is being explored in the ERC-funded Digital
Ludeme Project.
The aim of this inaugural international research meeting on DAL is to gather
together leading experts in relevant disciplines - computer science, artificial
intelligence, machine learning, computational phylogenetics, mathematics,
history, archaeology, anthropology, etc. - to discuss the key themes and
establish the foundations for this new field of research, so that it may
continue beyond the lifetime of its initiating project.Comment: Report on Dagstuhl Research Meeting. Authored/edited by all
participants. Appendices by Thierry Depauli
Perfil epidemiológico de pessoas sob cuidados paliativos em unidade hospitalar / Epidemiological profile of people under palliative care in a hospital unit
Objetivo: conhecer o perfil epidemiológico dos usuários do serviço hospitalar em Cuidados Paliativos de um hospital da rede privada em Fortaleza. Método: Estudo descritivo, com base no método de investigação quantitativa. Foram analisados prontuários de 80 pessoas atendidas no período de janeiro de 2018 a setembro de 2018. A amostra foi constituída por 80 indivíduos, sendo 42 usuários (53%) do sexo masculino, com 39 (49%) acima de 75 anos, apresentam múltiplas comorbidades 44 usuários (55 %). Majoritariamente acamados e dependentes das atividades de vida diárias (AVDs) 46 (58%) e 26 usuários (33%) permaneceram por períodos de internação prolongados maior que 50 dias, e em algum período da internação em unidade de terapia intensiva 55 (69%), possuindo múltiplos dispositivos invasivos. Conclusão: o perfil dos usuários é composto predominantemente por idosos, com dependência total para as atividades de vida diária com múltiplas comorbidades que permaneceram por longos períodos de internação hospitalar, requerendo implementação de estratégias que visem à condução destes casos.
A survey and classification of storage deduplication systems
The automatic elimination of duplicate data in a storage system commonly known as deduplication is increasingly accepted as an effective technique to reduce storage costs. Thus, it has been applied to different storage types, including archives and backups, primary storage, within solid state disks, and even to random access memory. Although the general approach to deduplication is shared by all storage types, each poses specific challenges and leads to different trade-offs and solutions. This diversity is often misunderstood, thus underestimating the relevance of new research and development.
The first contribution of this paper is a classification of deduplication systems according to six criteria that correspond to key design decisions: granularity, locality, timing, indexing, technique, and scope.
This classification identifies and describes the different approaches used for each of them. As a second contribution, we describe which combinations of these design decisions have been proposed and found more useful for challenges in each storage type. Finally, outstanding research challenges and unexplored design points are identified and discussed.This work is funded by the European Regional Development Fund (EDRF) through the COMPETE Programme (operational programme for competitiveness) and by National Funds through the Fundacao para a Ciencia e a Tecnologia (FCT; Portuguese Foundation for Science and Technology) within project RED FCOMP-01-0124-FEDER-010156 and the FCT by PhD scholarship SFRH-BD-71372-2010
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