scholarly journals A Probabilistic Approach for the Evaluation of Fault Detection Schemes in Microgrids

2017 ◽  
Vol 7 (5) ◽  
pp. 1967-1973 ◽  
Author(s):  
R. Eslami ◽  
S. H. H. Sadeghi ◽  
H. Askarian Abyaneh
Keyword(s):  
Fault Detection ◽  
Probabilistic Approach ◽  
Successful Performance ◽  
Three Phase ◽  
Important Challenge ◽  
Network Topologies ◽  
Location Type ◽  
High Degree ◽  
Detection Schemes ◽  
Very High

An important challenge in protection of a microgrid is the process of fault detection, considering the uncertainties in its topologies. Equally important is the evaluation of proposed methods as their incorrect performances could result in unreasonable power outages. In this paper, a new fault detection and characterization method is introduced and evaluated subject to the uncertainties of network topologies. The features of three-phase components together with the positive, negative and zero sequences of current and voltage waveforms are derived to detect the occurrence of a fault, its location, type and the engaged phases. The proposed method is independent of the microgrid topology. To evaluate the performance of the proposed method in various network topologies, a Monte Carlo scheme is developed. This is done by computing the expected energy not-supplied reliability index and the percentage of successful performance of the fault detection. Simulation results show that the proposed method can detect faults in various microgrid topologies with a very high degree of accuracy.

Electron Microscopy in Molecular Biology

1967 ◽  
Vol 25 ◽  
pp. 2-3
Author(s):  
Cecil E. Hall
Keyword(s):  
Electron Microscopy ◽  
Molecular Biology ◽  
Noise Level ◽  
Molecular Structures ◽  
Material Structure ◽  
The Arts ◽  
Shadow Casting ◽  
Electron Image ◽  
High Degree ◽  
Very High

The visualization of organic macromolecules such as proteins, nucleic acids, viruses and virus components has reached its high degree of effectiveness owing to refinements and reliability of instruments and to the invention of methods for enhancing the structure of these materials within the electron image. The latter techniques have been most important because what can be seen depends upon the molecular and atomic character of the object as modified which is rarely evident in the pristine material. Structure may thus be displayed by the arts of positive and negative staining, shadow casting, replication and other techniques. Enhancement of contrast, which delineates bounds of isolated macromolecules has been effected progressively over the years as illustrated in Figs. 1, 2, 3 and 4 by these methods. We now look to the future wondering what other visions are waiting to be seen. The instrument designers will need to exact from the arts of fabrication the performance that theory has prescribed as well as methods for phase and interference contrast with explorations of the potentialities of very high and very low voltages. Chemistry must play an increasingly important part in future progress by providing specific stain molecules of high visibility, substrates of vanishing “noise” level and means for preservation of molecular structures that usually exist in a solvated condition.

scholarly journals Multi-Locus Selection and the Structure of Variation at the white Gene of Drosophila melanogaster

Genetics ◽  
1996 ◽  
Vol 144 (2) ◽  
pp. 635-645 ◽  
Author(s):  
David A Kirby ◽  
Wolfgang Stephan
Keyword(s):  
Drosophila Melanogaster ◽  
White Gene ◽  
Transcriptional Unit ◽  
North American Population ◽  
Evolutionary Mechanisms ◽  
Locus Selection ◽  
Neutral Equilibrium ◽  
History Of ◽  
High Degree ◽  
Very High

Abstract We surveyed sequence variation and divergence for the entire 5972-bp transcriptional unit of the white gene in 15 lines of Drosophila melanogaster and one line of D. simulans. We found a very high degree of haplotypic structuring for the polymorphisms in the 3′ half of the gene, as opposed to the polymorphisms in the 5′ half. To determine the evolutionary mechanisms responsible for this pattern, we sequenced a 1612-bp segment of the white gene from an additional 33 lines of D. melanogaster from a European and a North American population. This 1612-bp segment encompasses an 834bp region of the white gene in which the polymorphisms form high frequency haplotypes that cannot be explained by a neutral equilibrium model of molecular evolution. The small number of recombinants in the 834bp region suggests epistatic selection as the cause of the haplotypic structuring, while an investigation of nucleotide diversity supports a directional selection hypothesis. A multi-locus selection model that combines features from both-hypotheses and takes the recent history of D. melanogaster into account may be the best explanation for these data.

Continuous DNA replication in the nucleus of the dinoflagellate Prorocentrum micans (Ehrenberg)

1977 ◽  
Vol 27 (1) ◽  
pp. 81-90
Author(s):  
S.A. Filfilan ◽  
D.C. Sigee
Keyword(s):  
Electron Microscope ◽  
Dna Synthesis ◽  
Nuclear Dna ◽  
Continuous Process ◽  
Prorocentrum Micans ◽  
Interphase Nuclei ◽  
Electron Microscope Autoradiography ◽  
Dividing Cells ◽  
High Degree ◽  
Very High

The uptake of tritiated thymine into cells of a heterogeneous population of Prorocentrum micans was investigated using light-microscope and electron-microscope autoradiography. Specificity of thymine uptake into DNA was demonstrated by the specific removal of label from wax-embedded material using DNase and by the high degree of localization of nuclear label to chromosomes in the electron-microscope autoradiographs. All nuclei, including both dividing and non-dividing cells, showed a substantial uptake of label, indicating that nuclear DNA synthesis in Prorocentrum micans is a continuous process. The level of DNA synthesis does show considerable variation, however, with very high levels in some interphase nuclei. The continuous replication of nuclear DNA provides further evidence of dinoflagellate affinity to the prokaryotes, and indicates that Prorocentrum micans is a very primitive eukaryote cell.

Decision Support System Based on Fuzzy Logic for Assessment of Expected Corporate Income Performance

2021 ◽  
pp. 2150009
Author(s):  
Arthur Yosef ◽  
Eli Shnaider ◽  
Rimona Palas ◽  
Amos Baranes
Keyword(s):  
Fuzzy Logic ◽  
Decision Support ◽  
Operating Income ◽  
Explanatory Variables ◽  
Section Model ◽  
Evaluation Mechanism ◽  
One Year ◽  
High Degree ◽  
Decision Support Method ◽  
Very High

This study presents a decision-support method to estimate the next year performance of corporate Operating Income Margin (OIM). It is based on a unique combination of cross-section model and the rules-based evaluation mechanism. The estimate is done in terms of broad categories, and not precise numerical values. The model is constructed as follows: its dependent variable (OIM) is one year ahead vs. the corresponding explanatory variables. This structure of the model allows us to view explanatory variables as reflecting financial potential of corporations. The evaluation component consists of a set of rules designed to identify the companies whose “potential” clearly points to an opportunity to invest. For the method presented here to succeed, it is necessary to utilize a highly reliable modeling method, even if it is “Fuzzy”. We apply Soft Regression (SR), which is a Soft Computing modeling tool based on Fuzzy Logic, and utilize all available proxy variables by creating intervals of values. Advantages of utilizing SR, and the intervals’-based modeling are extensively discussed. Modeling results for five consecutive years are consistent and stable, thus indicating high degree of reliability. Testing indicates very high success rate for the stock market related domain, the lowest being 87.9%.

scholarly journals Application of Machine Learning for Fault Classification and Location in a Radial Distribution Grid

2020 ◽  
Vol 10 (14) ◽  
pp. 4965
Author(s):  
Yordanos Dametw Mamuya ◽  
Yih-Der Lee ◽  
Jing-Wen Shen ◽  
Md Shafiullah ◽  
Cheng-Chien Kuo
Keyword(s):  
Machine Learning ◽  
Fault Detection ◽  
Radial Distribution ◽  
Fault Classification ◽  
Discrete Wavelet ◽  
Efficiency Coefficient ◽  
Distribution Grid ◽  
Phase Current ◽  
Three Phase ◽  
Types Of Faults

Fault location with the highest possible accuracy has a significant role in expediting the restoration process, after being exposed to any kind of fault in power distribution grids. This paper provides fault detection, classification, and location methods using machine learning tools and advanced signal processing for a radial distribution grid. The three-phase current signals, one cycle before and one cycle after the inception of the fault are measured at the sending end of the grid. A discrete wavelet transform (DWT) is employed to extract useful features from the three-phase current signal. Standard statistical techniques are then applied onto DWT coefficients to extract the useful features. Among many features, mean, standard deviation (SD), energy, skewness, kurtosis, and entropy are evaluated and fed into the artificial neural network (ANN), Multilayer perceptron (MLP), and extreme learning machine (ELM), to identify the fault type and its location. During the training process, all types of faults with variations in the loading and fault resistance are considered. The performance of the proposed fault locating methods is evaluated in terms of root mean absolute percentage error (MAPE), root mean squared error (RMSE), Willmott’s index of agreement (WIA), coefficient of determination ( R 2 ), and Nash-Sutcliffe model efficiency coefficient (NSEC). The time it takes for training and testing are also considered. The proposed method that discrete wavelet transforms with machine learning is a very accurate and reliable method for fault classifying and locating in both a balanced and unbalanced radial system. 100% fault detection accuracy is achieved for all types of faults. Except for the slight confusion of three line to ground (3LG) and three line (3L) faults, 100% classification accuracy is also achieved. The performance measures show that both MLP and ELM are very accurate and comparative in locating faults. The method can be further applied for meshed networks with multiple distributed generators. Renewable generations in the form of distributed generation units can also be studied.

scholarly journals CYTOPLASMIC DNA SYNTHESIS IN AMOEBA PROTEUS

1962 ◽  
Vol 15 (3) ◽  
pp. 525-534 ◽  
Author(s):  
M. Rabinovitch ◽  
W. Plaut
Keyword(s):  
Dna Synthesis ◽  
Tritiated Thymidine ◽  
Amoeba Proteus ◽  
Living Cells ◽  
Large Numbers ◽  
Cytoplasmic Dna ◽  
Basic Dyes ◽  
Nuclease Digestion ◽  
High Degree ◽  
Very High

The incorporation of tritiated thymidine in Amoeba proteus was reinvestigated in order to see if it could be associated with microscopically detectable structures. Staining experiments with basic dyes, including the fluorochrome acridine orange, revealed the presence of large numbers of 0.3 to 0.5 µ particles in the cytoplasm of all cells studied. The effect of nuclease digestion on the dye affinity of the particles suggests that they contain DNA as well as RNA. Centrifugation of living cells at 10,000 g leads to the sedimentation of the particles in the centrifugal third of the ameba near the nucleus. Analysis of centrifuged cells which had been incubated with H3-thymidine showed a very high degree of correlation between the location of the nucleic acid-containing granules and that of acid-insoluble, deoxyribonuclease-sensitive labeled molecules and leads to the conclusion that cytoplasmic DNA synthesis in Amoeba proteus occurs in association with these particles.

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