Knowledge of sampling methods is essential to design quality research. Critical questions are provided to help researchers choose a sampling method. This article reviews probability and non-probability sampling method...
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Knowledge of sampling methods is essential to design quality research. Critical questions are provided to help researchers choose a sampling method. This article reviews probability and non-probability sampling methods, lists and defines specific sampling techniques, and provides pros and cons for consideration. In addition, issues related to sampling methods are described to highlight potential problems.
This study explores the uncertainty in severe accident analysis of nuclear power plants, focusing on the thermal-hydraulic parameters of the WWER1000 reactor during station black-out scenarios. The primary challenge i...
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This study explores the uncertainty in severe accident analysis of nuclear power plants, focusing on the thermal-hydraulic parameters of the WWER1000 reactor during station black-out scenarios. The primary challenge in such analyses lies in the inherent uncertainties associated with the simplifying assumptions embedded in computational codes. To address this, five prominent sampling methods-simple generation sampling, Latin hypercube sampling, SOBOL, HALTON, and LHS-SOBOL-are applied to improve the MELCOR code's predictive accuracy. The results highlight that SGS produces non-uniform input distributions and performs poorly in comparison to the other methods. Additionally, key parameters, including hydrogen production, maximum containment pressure, and reactor pressure vessel rupture time, show significant variability, ranging from 150 to 602 kg, 14,100 to 28,000 s, and 0.62 to 1.05 MPa, respectively, with a 95 % confidence level. The findings emphasize the importance of selecting robust sampling techniques for enhancing the reliability of nuclear safety assessments.
This study aims to evaluate the efficiency of electric fishing and seine-net/dip-net to obtain quantitative and qualitative data on the fish community of low conductivity streams in the semi-arid region of Bahia, Braz...
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This study aims to evaluate the efficiency of electric fishing and seine-net/dip-net to obtain quantitative and qualitative data on the fish community of low conductivity streams in the semi-arid region of Bahia, Brazil. samplings were collected in 15 streams in the region of Chapada Diamantina. Two homogeneous stretches with 50 m each were selected and closed with blocking nets. Zippin analysis was used to evaluate the suitability of each capture method. Differences in abundance, richness, composition of species, and length of specimens captured were compared for each method. Twenty-nine species were collected, twenty-four using electric fishing, and twenty-one using seine-net/dip-net. There were no significant differences between methods as for abundance, richness, composition of species, and length of the individual captured. There were no significant differences in capturability. Both methods have high values of sample efficiency (SE). Therefore, electric fishing and seine-net/dip-net are equally effective on describing qualitatively and quantitatively the fish community. It is noteworthy that for an ideal choice of collection method, the geomorphological characteristics of the streams must be taken into account since they exert a direct influence on both collection methods.
The exponential expansion of data generation in the internet age has had a major impact on a number of sectors, including medical exploration. still, handling unstable datasets is one of the difficulties faced by expe...
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ISBN:
(数字)9798331520762
ISBN:
(纸本)9798331520779
The exponential expansion of data generation in the internet age has had a major impact on a number of sectors, including medical exploration. still, handling unstable datasets is one of the difficulties faced by experimenters in the field of drug. This problem occurs when there's an unstable distribution of classes in a dataset, which could lead to one class being mainly more multitudinous than the others. The creation of precise individual models can be seriously hampered by imbalanced datasets. In this design, we concentrate on two medical datasets the PIMA INDIAN DIABETICS dataset and the habitual order complaint dataset. Experimenters have been probing a number of styles to balance the datasets previous to training machine literacy models in order to overcome this difficulty. Data about people's health characteristics, similar as blood pressure, blood sugar, and other material clinical pointers, are included in these databases. The quantum of data generated is growing snappily in the period of the internet. Research in medical supplementary opinion is decreasingly being backed by artificial intelligence, especially big data categorization technologies. still, because sample crops differ, medical big data constantly has imbalances. In general, the term “imbalanced data” describes a situation where several data samples within a specific problem are not distributed unevenly, which results in one or further classes in the dataset being underrepresented. Traditional bracket ways generally assume that training misclassification costs are the same for all classes and that each class has an analogous quantum of samples.
To evaluate the classification accuracy of a classification algorithm on a certain dataset, it is necessary to sample training and test data from the original dataset. After building the classification model from the ...
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ISBN:
(数字)9798331507022
ISBN:
(纸本)9798331507039
To evaluate the classification accuracy of a classification algorithm on a certain dataset, it is necessary to sample training and test data from the original dataset. After building the classification model from the training data, the test data can be used to evaluate the classification accuracy. However, in order to evaluate the classification accuracy of a classification algorithm on an original dataset, it is usually necessary to sample the training/test data many times, build the classification model many times, and then average the accuracies of all the evaluation, which will consume a lot of time and resources. To address this, we propose a sampling method so that the sampled training/test data can replace the results of building multiple models and averaging multiple classification accuracy, that is close to the evaluation results of the original data. Our approach introduces different methods for calculating the similarity of data distributions and incorporates feature weights in the similarity calculation process to select training/test sets that are close to the distribution of the original dataset.
Animals perform a continuous stream of behavior throughout their lives. Because their behavior is not random, appropriate sampling methods can be used to obtain data that accurately reflect the actual behavior and are...
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Animals perform a continuous stream of behavior throughout their lives. Because their behavior is not random, appropriate sampling methods can be used to obtain data that accurately reflect the actual behavior and are valid for answering research questions. Answering questions related to several variables assists in narrowing the choices of sampling methods. First, a determination must be made of what behaviors to measure. If the behaviors are few and easily measured, then All Occurrences sampling is the method of choice because it generates accurate frequency and duration data through continuous recording. Sequence and Sociometric Matrix sampling are specialized types of All Occurrences sampling that are restricted to sampling intra- or interindividual sequences and social interactions (e.g., agonistic), respectively. Second, if who (e.g., specific individual, sex, or genotype) performs the behavior is a major component of the research question, then consideration should be given to Focal Animal (Pair, Group) sampling. Third, if when or where the behavior is performed is of interest (e.g., activity budget), then Instantaneous or Scan sampling can often be effective. Ad libitum sampling does not produce valid data for analyses, but it is useful when formulating and fine-tuning research questions. One-Zero sampling is not recommended except when the research question relates to the presence or absence of behaviors only. Other factors to consider in selecting a sampling method are duration of the behavior (event or state), desired scale of measurement (nominal, ordinal, interval, or ratio), and logistics (e.g., time, and equipment and facilities available).
A total of 160 consecutive isolates of Neisseria gonorrhoeae was collected over a 3-month period. They were tested for their susceptibility to penicillin, erythromycin and spectinomycin and the auxotype and the seroty...
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A total of 160 consecutive isolates of Neisseria gonorrhoeae was collected over a 3-month period. They were tested for their susceptibility to penicillin, erythromycin and spectinomycin and the auxotype and the serotype determined. We have evaluated two sampling methods, the collection of every fifth isolate and the first 20 isolates (10 male and 10 female) each month, to determine whether either is representative of the total population. There was no significant difference between either method of sampling and the total for detecting the predominant auxotypes and serovars or the distributions in antibiotic susceptibility. It is possible to monitor major changes in a gonococcal population, particularly susceptibility to antibiotics, using a sample of the total population.
In recent years, there are growing concerns of emerging organic contaminants (EOCs) owing to their potential adverse impacts on human health. Lots of EOCs are used in civilian products and considered as primary contam...
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In recent years, there are growing concerns of emerging organic contaminants (EOCs) owing to their potential adverse impacts on human health. Lots of EOCs are used in civilian products and considered as primary contaminants in indoor environment. Developing efficient air sampling techniques are prerequisite to evaluate EOC contaminations in indoor environment. This article aims to review the temporal trends of indoor air sampling techniques of several typical EOCs, i.e. brominated flame retardants, phthalates, pharmaceutics and personal care products, and per-and polyfluoroalkyl substances. Although some progress has been made in this field, there is still a large gap to be filled in the monitoring of EOCs in indoor air. (C) 2016 Published by Elsevier B.V.
A review is presented of methods for sampling phlebotomine sandflies (Diptera: Psychodidae). Among similar to 500 species of Phlebotominae so far described, mostly in the New World genus Lutzomyia and the Old World ge...
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A review is presented of methods for sampling phlebotomine sandflies (Diptera: Psychodidae). Among similar to 500 species of Phlebotominae so far described, mostly in the New World genus Lutzomyia and the Old World genus Phlebotomus, about 10% are known vectors of Leishmania parasites or other pathogens. Despite being small and fragile, sandflies have a wide geographical range with species occupying a considerable diversity of ecotopes and habitats, from deserts to humid forests, so that suitable methods for collecting them are influenced by environmental conditions where they are sought. Because immature phlebotomines occupy obscure terrestrial habitats, it is difficult to find their breeding sites. Therefore, most trapping methods and sampling procedures focus on sandfly adults, whether resting or active. The diurnal resting sites of adult sandflies include tree holes, buttress roots, rock crevices, houses, animal shelters and burrows, from which they may be aspirated directly or trapped after being disturbed. Sandflies can be collected during their periods of activity by interception traps, or by using attractants such as bait animals, CO2 or light. The method of trapping used should: (a) be suited to the habitat and area to be surveyed, (b) take into account the segment of the sandfly population to be sampled (species, sex and reproduction condition) and (c) yield specimens of appropriate condition for the study objectives (e.g. identification of species present, population genetics or vector implication). methods for preservation and transportation of sandflies to the laboratory also depend on the objectives of a particular study and are described accordingly.
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