Zeitschriftenartikel: „Geometric quantile“

1

Cheng, Yebin, und Jan G. De Gooijer. „On the uth geometric conditional quantile“. Journal of Statistical Planning and Inference 137, Nr. 6 (Juni 2007): 1914–30. http://dx.doi.org/10.1016/j.jspi.2006.02.014.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

2

Sathar, E. I. Abdul, und Veena L. Vijayan. „Quantile Based Geometric Vitality Function of Order Statistics“. Mathematical Methods of Statistics 32, Nr. 1 (März 2023): 88–101. http://dx.doi.org/10.3103/s1066530723010040.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

3

Kim, Hyuk Joo. „A Study on Computing Sample Quantiles of Discrete Probability Distributions“. Korean Data Analysis Society 26, Nr. 1 (29.02.2024): 175–86. http://dx.doi.org/10.37727/jkdas.2024.26.1.175.

Der volle Inhalt der Quelle

Annotation:

In this paper, we studied the methods of computing sample quantiles for the case of discrete probability distributions. There are two main methods which are introduced in statistics textbooks. We compared these two methods by simulation from practical and educational necessity. We considered some cases of Poisson, binomial, geometric, negative binomial, and discrete uniform distributions by setting up the parameters, and for each distribution we performed 10,000 times of simulation of drawing random samples of size 20 and 50. At each time of simulation, we computed the difference between the population quantile and the sample quantile obtained by each method. We compared the two methods by using two criteria: one is the mean square error over 10,000 times of simulation, and the other is the frequency of obtaining closer sample quantile to the population quantile than the competing method. We also obtained the estimated probabilities of exact estimation of population quantiles for the two methods, and performed the tests of homogeneity on the probability distribution of under-estimation, exact estimation, and over-estimation of the population quantiles.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

4

Khare, Kshitij, und James P. Hobert. „Geometric ergodicity of the Gibbs sampler for Bayesian quantile regression“. Journal of Multivariate Analysis 112 (November 2012): 108–16. http://dx.doi.org/10.1016/j.jmva.2012.05.004.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

5

Arshad, Rana Muhammad Imran, Christophe Chesneau und Farrukh Jamal. „The Odd Gamma Weibull-Geometric Model: Theory and Applications“. Mathematics 7, Nr. 5 (02.05.2019): 399. http://dx.doi.org/10.3390/math7050399.

Der volle Inhalt der Quelle

Annotation:

In this paper, we study a new four-parameter distribution called the odd gamma Weibull-geometric distribution. Having the qualities suggested by its name, the new distribution is a special member of the odd-gamma-G family of distributions, defined with the Weibull-geometric distribution as baseline, benefiting of their respective merits. Firstly, we present a comprehensive account of its mathematical properties, including shapes, asymptotes, quantile function, quantile density function, skewness, kurtosis, moments, moment generating function and stochastic ordering. Then, we focus our attention on the statistical inference of the corresponding model. The maximum likelihood estimation method is used to estimate the model parameters. The performance of this method is assessed by a Monte Carlo simulation study. An empirical illustration of the new distribution is presented by the analyses two real-life data sets. The results of the proposed model reveal to be better as compared to those of the useful beta-Weibull, gamma-Weibull and Weibull-geometric models.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

6

Li, Shuang, und Jie Shan. „Adaptive Geometric Interval Classifier“. ISPRS International Journal of Geo-Information 11, Nr. 8 (31.07.2022): 430. http://dx.doi.org/10.3390/ijgi11080430.

Der volle Inhalt der Quelle

Annotation:

Quantile, equal interval, and natural breaks methods are widely used data classification methods in geospatial analysis and cartography. However, when applied to data with skewed distributions, they can only reveal the variations of either high frequent values or extremes, which often leads to undesired and biased classification results. To handle this problem, Esri provided a compromise method, named geometric interval classification (GIC). Although GIC performs well for various classification tasks, its mathematics and solution process remain unclear. Moreover, GIC is theoretically only applicable to single-peak (single-modal), one-dimensional data. This paper first mathematically formulates GIC as a general optimization problem subject to equality constraint. We then further adapt such formulated GIC to handle multi-peak and multi-dimensional data. Both thematic data and remote sensing images are used in this study. The comparison with other classification methods demonstrates the advantage of GIC being able to highlight both middle and extreme values. As such, it can be regarded as a general data classification approach for thematic mapping and other geospatial applications.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

7

Peng, Bo, Zhengqiu Xu und Min Wang. „The Exponentiated Lindley Geometric Distribution with Applications“. Entropy 21, Nr. 5 (20.05.2019): 510. http://dx.doi.org/10.3390/e21050510.

Der volle Inhalt der Quelle

Annotation:

We introduce a new three-parameter lifetime distribution, the exponentiated Lindley geometric distribution, which exhibits increasing, decreasing, unimodal, and bathtub shaped hazard rates. We provide statistical properties of the new distribution, including shape of the probability density function, hazard rate function, quantile function, order statistics, moments, residual life function, mean deviations, Bonferroni and Lorenz curves, and entropies. We use maximum likelihood estimation of the unknown parameters, and an Expectation-Maximization algorithm is also developed to find the maximum likelihood estimates. The Fisher information matrix is provided to construct the asymptotic confidence intervals. Finally, two real-data examples are analyzed for illustrative purposes.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

8

Huang, Mei Ling, und Xiang Raney-Yan. „A Method for Confidence Intervals of High Quantiles“. Entropy 23, Nr. 1 (04.01.2021): 70. http://dx.doi.org/10.3390/e23010070.

Der volle Inhalt der Quelle

Annotation:

The high quantile estimation of heavy tailed distributions has many important applications. There are theoretical difficulties in studying heavy tailed distributions since they often have infinite moments. There are also bias issues with the existing methods of confidence intervals (CIs) of high quantiles. This paper proposes a new estimator for high quantiles based on the geometric mean. The new estimator has good asymptotic properties as well as it provides a computational algorithm for estimating confidence intervals of high quantiles. The new estimator avoids difficulties, improves efficiency and reduces bias. Comparisons of efficiencies and biases of the new estimator relative to existing estimators are studied. The theoretical are confirmed through Monte Carlo simulations. Finally, the applications on two real-world examples are provided.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

9

Ramires, Thiago, Edwin Ortega, Gauss Cordeiro und Gholamhoss Hamedani. „The beta generalized half-normal geometric distribution“. Studia Scientiarum Mathematicarum Hungarica 50, Nr. 4 (01.12.2013): 523–54. http://dx.doi.org/10.1556/sscmath.50.2013.4.1258.

Der volle Inhalt der Quelle

Annotation:

The beta generalized half-normal distribution is commonly used to model lifetimes. We propose a new wider distribution called the beta generalized half-normal geometric distribution, whose failure rate function can be decreasing, increasing or upside-down bathtub. Its density function can be expressed as a linear combination of beta generalzed half-normal density functions. We derive quantile function, moments and generating unction. We characterize the proposed distribution using a simple relationship between wo truncated moments. The method of maximum likelihood is adapted to estimate the model parameters and its potentiality is illustrated with an application to a real fatigue data set. Further, we propose a new extended regression model based on the logarithm of the new distribution. This regression model can be very useful for the analysis of real data and provide more realistic fits than other special regression models.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

10

Ramadan, Ahmed T., Ahlam H. Tolba und Beih S. El-Desouky. „A Unit Half-Logistic Geometric Distribution and Its Application in Insurance“. Axioms 11, Nr. 12 (28.11.2022): 676. http://dx.doi.org/10.3390/axioms11120676.

Der volle Inhalt der Quelle

Annotation:

A new one parameter distribution recently was proposed for modelling lifetime data called half logistic-geometric (HLG) distribution. In this paper, appropriate transformation is considered for HLG distribution and a new distribution is derived called unit half logistic-geometric (UHLG) distribution for modelling bounded data in the interval (0, 1). Some important statistical properties are investigated with a closed form quantile function. Some methods of parameter estimation are introduced to evaluate the distribution parameter and a simulation study is introduced to compare these different methods. A real data application in the insurance field is introduced to show the flexibility of the new distribution modelling such data comparing with other distributions.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

11

Bottai, Matteo. „A regression method for modelling geometric rates“. Statistical Methods in Medical Research 26, Nr. 6 (18.09.2015): 2700–2707. http://dx.doi.org/10.1177/0962280215606474.

Der volle Inhalt der Quelle

Annotation:

The occurrence of an event of interest over time is often summarized by the incidence rate, defined as the average number of events per person-time. This type of rate applies to events that may occur repeatedly over time on any given subject, such as infections, and Poisson regression represents a natural regression method for modelling the effect of covariates on it. However, for events that can occur only once, such as death, the geometric rate may be a better summary measure. The geometric rate has long been utilized in demography for studying the growth of populations and in finance to compute compound interest on capital. This type of rate, however, is virtually unknown to medical research. This may be partly a consequence of the lack of a regression method for it. This paper describes a regression method for modelling the effect of covariates on the geometric rate. The described method is based on applying quantile regression to a transform of the time-to-event variable. The proposed method is used to analyze mortality in a randomized clinical trial and in an observational epidemiological study.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

12

Nasiru, Suleman, Christophe Chesneau, Abdul Ghaniyyu Abubakari und Irene Dekomwine Angbing. „Generalized Unit Half-Logistic Geometric Distribution: Properties and Regression with Applications to Insurance“. Analytics 2, Nr. 2 (16.05.2023): 438–62. http://dx.doi.org/10.3390/analytics2020025.

Der volle Inhalt der Quelle

Annotation:

The use of distributions to model and quantify risk is essential in risk assessment and management. In this study, the generalized unit half-logistic geometric (GUHLG) distribution is developed to model bounded insurance data on the unit interval. The corresponding probability density function plots indicate that the related distribution can handle data that exhibit left-skewed, right-skewed, symmetric, reversed-J, and bathtub shapes. The hazard rate function also suggests that the distribution can be applied to analyze data with bathtubs, N-shapes, and increasing failure rates. Subsequently, the inferential aspects of the proposed model are investigated. In particular, Monte Carlo simulation exercises are carried out to examine the performance of the estimation method by using an algorithm to generate random observations from the quantile function. The results of the simulation suggest that the considered estimation method is efficient. The univariate application of the distribution and the multivariate application of the associated regression using risk survey data reveal that the model provides a better fit than the other existing distributions and regression models. Under the multivariate application, we estimate the parameters of the regression model using both maximum likelihood and Bayesian estimations. The estimates of the parameters for the two methods are very close. Diagnostic plots of the Bayesian method using the trace, ergodic, and autocorrelation plots reveal that the chains converge to a stationary distribution.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

13

HOBSON, DAVID, und JEREMY PENN. „MAXIMIZING THE PROBABILITY OF A PERFECT HEDGE USING AN IMPERFECTLY CORRELATED INSTRUMENT“. International Journal of Theoretical and Applied Finance 08, Nr. 06 (September 2005): 763–89. http://dx.doi.org/10.1142/s0219024905003220.

Der volle Inhalt der Quelle

Annotation:

Let Xϕ denote the trading wealth generated using a strategy ϕ, and let CT be a contingent claim which is not spanned by the traded assets. Consider the problem of finding the strategy which maximizes the probability of terminal wealth meeting or exceeding the claim value at some fixed time horizon, i.e., of finding [Formula: see text]. This problem is sometimes referred to as the quantile hedging problem. We consider the quantile hedging problem when the traded asset and the contingent claim are correlated geometric Brownian motions. This fits with several important examples. One of the benefits of working with such a concrete model is that although it is incomplete we can still do calculations. In particular, we can consider some detailed issues such as the impact of the timing at which information about CT is revealed.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

14

Prataviera, Fábio, Gauss M. Cordeiro, Edwin M. M. Ortega und Adriano K. Suzuki. „The Odd Log-Logistic Geometric Normal Regression Model with Applications“. Advances in Data Science and Adaptive Analysis 11, Nr. 01n02 (April 2019): 1950003. http://dx.doi.org/10.1142/s2424922x19500037.

Der volle Inhalt der Quelle

Annotation:

In several applications, the distribution of the data is frequently unimodal, asymmetric or bimodal. The regression models commonly used for applications to data with real support are the normal, skew normal, beta normal and gamma normal, among others. We define a new regression model based on the odd log-logistic geometric normal distribution for modeling asymmetric or bimodal data with support in [Formula: see text], which generalizes some known regression models including the widely known heteroscedastic linear regression. We adopt the maximum likelihood method for estimating the model parameters and define diagnostic measures to detect influential observations. For some parameter settings, sample sizes and different systematic structures, various simulations are performed to verify the adequacy of the estimators of the model parameters. The empirical distribution of the quantile residuals is investigated and compared with the standard normal distribution. We prove empirically the usefulness of the proposed models by means of three applications to real data.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

15

Louzada, Francisco, Cintia Y. Yamachi, Vitor A. A. Marchi und Maria A. P. Franco. „The long-term exponentiated complementary exponential geometric distribution under a latent complementary causes framework“. TEMA (São Carlos) 15, Nr. 1 (12.07.2014): 019. http://dx.doi.org/10.5540/tema.2014.015.01.0019.

Der volle Inhalt der Quelle

Annotation:

<p><span>A new lifetime distribution which accommodates decreasing and unimodal hazard function is proposed in this paper. It is derived from the exponentiated complementary exponential geometric distribution and has it genesis on the compounding the exponential and geometric distributions. It can be used on a latent complementary causes scenario, where onle thethe minimum lifetime among all causes is observed. We derive the density, quantile, survival and failure rate functions for the proposed distribution, as well as some proprieties such as the characteristic function, mean, variance and r-th order statistics. The estimation is based on maximum likelihood approach. A simulation study performed in order to assess the performance of the maximum likelihood estimates of the parameters of the proposed distribution. The methodology is illustrated in three real datasets. </span></p>

APA, Harvard, Vancouver, ISO und andere Zitierweisen

16

Magnussen, S., und P. Boudewyn. „Derivations of stand heights from airborne laser scanner data with canopy-based quantile estimators“. Canadian Journal of Forest Research 28, Nr. 7 (01.07.1998): 1016–31. http://dx.doi.org/10.1139/x98-078.

Der volle Inhalt der Quelle

Annotation:

The distribution of canopy heights obtained with an airborne laser scanner over a field trial with Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) was a function of the vertical distribution of foliage area. Over a wide range of canopy structures, the proportion of laser pulses returned from or above a given reference height was proportional to the fraction of leaf area above it. We hypothesized that the quantile of the laser canopy heights matching in probability the fraction of leaf area above a desired height would be an unbiased estimator of same. This was confirmed in 36 (20 × 20 m) plots and 6 older validation plots. Canopy-based quantiles of the laser canopy height data were within 6% (mean 3%) of the field estimates. Laser and field estimates were strongly correlated (r ~ 0.8), and statistical tests supported the null hypotheses of no difference in mean stand height (P > 0.3). A geometric model successfully predicted the mean difference between the laser canopy heights and the mean tree height. Our results explicate why estimation of stand heights from laser scanner data based on the maximum canopy height value in each cell of a fixed area grid has been successful in practice.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

17

Faraz, Humaira, Fahim Raees und Mirza Mahmood Baig. „Capturing the role of rural consumers in sensitive price indicator through geometric consistency check on urban and rural market prices“. Mehran University Research Journal of Engineering and Technology 42, Nr. 4 (27.09.2023): 01. http://dx.doi.org/10.22581/muet1982.2304.2567.

Der volle Inhalt der Quelle

Annotation:

This paper focuses on capturing price movement and price stability in rural and urban markets. Pakistan collects prices from both markets, but only for the computation of the Consumer Price Index (CPI), which is calculated on a monthly basis. It is proposed to include rural markets by widening the scope of the Sensitive Price Indicator (SPI), computed by the Pakistan Bureau of Statistics (PBS). The inconsistency in the prices of rural markets is observed on the basis of different measures, including descriptive and inferential statistics. Therefore, it is suggested to include rural markets as well in the SPI computation. Large numbers of head counts make transactions in rural areas, which may be taken into account for capturing the accurate weekly consumption pattern of the consumers. Prices of all SPI items were taken from urban and rural markets and checked for normality through the Kolmogorov-Smirnovand Shapiro-Wilk tests. Further, the normality was checked graphically by the Q-Q plot (Quantile-Quantile plot) and histogram. Due to the skewness of the data, non-parametric methods like the geometric coefficient of variation and the coefficient of mean deviation from the median have been applied to check the consistency of the prices in rural markets. The prices of rural markets for further framing of policy to widen the scope of capturing the movement of prices.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

18

Warahena-Liyanage, Gayan, Felix Famoye und Carl Lee. „A Generalization of LASSO Modeling via Bayesian Interpretation“. Austrian Journal of Statistics 52, Nr. 4 (19.07.2023): 15–45. http://dx.doi.org/10.17713/ajs.v52i4.1455.

Der volle Inhalt der Quelle

Annotation:

The aim of this paper is to introduce a generalized LASSO regression model that is derived using a generalized Laplace (GL) distribution. Five different GL distributions are obtained through the T -R{Y } framework with quantile functions of standard uniform, Weibull, log-logistic, logistic, and extreme value distributions. The properties, including quantile function, mode, and Shannon entropy of these GL distributions are derived. A particular case of GL distributions called the beta-Laplace distribution is explored. Some additional components to the constraint in the ordinary LASSO regression model are obtained through the Bayesian interpretation of LASSO with beta-Laplace priors. The geometric interpretations of these additional components are presented. The effects of the parameters from beta-Laplace distribution in the generalized LASSO regression model are also discussed. Two real data sets are analyzed to illustrate the flexibility and usefulness of the generalized LASSO regression model in the process of variable selection with better prediction performance. Consequently, this research study demonstrates that more flexible statistical distributions can be used to enhance LASSO in terms of flexibility in variable selection and shrinkage with better prediction.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

19

Angbing, Irene Dekomwine, Suleman Nasiru und Dioggban Jakperik. „Sine-Weibull Geometric Mixture and Nonmixture Cure Rate Models with Applications to Lifetime Data“. International Journal of Mathematics and Mathematical Sciences 2022 (08.08.2022): 1–13. http://dx.doi.org/10.1155/2022/1798278.

Der volle Inhalt der Quelle

Annotation:

In this study, two new distributions are developed by compounding Sine-Weibull and zero-truncated geometric distributions. The quantile and ordinary moments of the distributions are obtained. Plots of the hazard rate functions of the distributions show that the distributions exhibit nonmonotonic failure rates. Also, plots of the densities of the distributions show that they exhibit decreasing, skewed, and approximately symmetric shapes, among others. Mixture and nonmixture cure rate models based on these distributions are also developed. The estimators of the parameters of the cure rate models are shown to be consistent via simulation studies. Covariates are introduced into the cure rate models via the logit link function. Finally, the performance of the distributions and the cure rate and regression models is demonstrated using real datasets. The results show that the developed distributions can serve as alternatives to existing models for survival data analyses.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

20

Farooq, Muhammad, Muhammad Mohsin, Muhammad Naeem, Muhammad Farman, Ali Akgul und Muhammad Saleem. „Discretization of the method of generating an expanded family of distributions based upon truncated distributions“. Thermal Science 25, Spec. issue 1 (2021): 19–30. http://dx.doi.org/10.2298/tsci200605003f.

Der volle Inhalt der Quelle

Annotation:

Discretization translates the continuous functions into discrete version making them more adaptable for numerical computation and application in applied mathematics and computer sciences. In this article, discrete analogues of a generalization method of generating a new family of distributions is provided. Several new discrete distributions are derived using the proposed methodology. A discrete Weibull-Geometric distribution is considered and various of its significant characteristics including moment, survival function, reliability function, quantile function, and order statistics are discussed. The method of maximum likelihood and the method of moments are used to estimate the model parameters. The performance of the proposed model is probed through a real data set. A comparison of our model with some existing models is also given to demonstrate its efficiency.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

21

Andrews-Trevino, Johanna Y., Patrick Webb, Gerald Shively, Beatrice Rogers, Kedar Baral, Dale Davis, Krishna Paudel et al. „Dietary determinants of aflatoxin B1-lysine adduct in pregnant women consuming a rice-dominated diet in Nepal“. European Journal of Clinical Nutrition 74, Nr. 5 (02.01.2020): 732–40. http://dx.doi.org/10.1038/s41430-019-0554-2.

Der volle Inhalt der Quelle

Annotation:

Abstract Background Aflatoxins are found in diverse foods widely consumed worldwide. This study investigated the association between aflatoxin exposure and (a) consumption of specific foods, (b) dietary diversity (DD), and (c) seasonality. Methods Women enrolled in the AflaCohort Study in Banke, Nepal (n = 1648) were asked how often they ate certain food items in the past 7 days and 24 h. Serum aflatoxin B1-lysine (AFB1-lys) adduct levels, measured during pregnancy, were determined using high-performance liquid chromatography. Multivariable ordinary least squares and quantile regression models were used to examine incremental increases in AFB1-lys adduct levels per frequency of food consumption and the relationship between DD, seasonality, and increases in AFB1-lys adduct. Results Roughly 94% of women were exposed to aflatoxin (geometric mean 1.37 pg/mg). Women in the 30th, 50th, and 70th quantiles of aflatoxin exposure who reported one more occasion of maize consumption in the past week showed increases in AFB1-lys adduct levels: 0.094, 0.112, and 0.109 pg/mg (p < 0.05, all). Women in the 30th, 50th, 70th, and 90th quantiles of exposure who reported one more occasion of groundnut consumption in the past week also showed increases in AFB1-lys adduct levels: 0.058 (p < 0.001), 0.085 (p < 0.01), 0.133 (p < 0.001), and 0.133 (p < 0.001) pg/mg. Winter month recruitment was positively associated with AFB1-lys adduct levels at all quantiles of aflatoxin exposure (range: 0.313–1.101 pg/mg, p < 0.001). DD was not predictive of aflatoxin exposure. Conclusions Our findings justify integrated approaches to aflatoxin reduction, including regulatory, agricultural, and food safety interventions across the value chain and at the household level.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

22

Kim, Wonkook, Sunghun Jung, Yongseon Moon und Stephen C. Mangum. „Morphological Band Registration of Multispectral Cameras for Water Quality Analysis with Unmanned Aerial Vehicle“. Remote Sensing 12, Nr. 12 (24.06.2020): 2024. http://dx.doi.org/10.3390/rs12122024.

Der volle Inhalt der Quelle

Annotation:

Multispectral imagery contains abundant spectral information on terrestrial and oceanic targets, and retrieval of the geophysical variables of the targets is possible when the radiometric integrity of the data is secured. Multispectral cameras typically require the registration of individual band images because their lens locations for individual bands are often displaced from each other, thereby generating images of different viewing angles. Although this type of displacement can be corrected through a geometric transformation of the image coordinates, a mismatch or misregistration between the bands still remains, owing to the image acquisition timing that differs by bands. Even a short time difference is critical for the image quality of fast-moving targets, such as water surfaces, and this type of deformation cannot be compensated for with a geometric transformation between the bands. This study proposes a novel morphological band registration technique, based on the quantile matching method, for which the correspondence between the pixels of different bands is not sought by their geometric relationship, but by the radiometric distribution constructed in the vicinity of the pixel. In this study, a Micasense Rededge-M camera was operated on an unmanned aerial vehicle and multispectral images of coastal areas were acquired at various altitudes to examine the performance of the proposed method for different spatial scales. To assess the impact of the correction on a geophysical variable, the performance of the proposed method was evaluated for the chlorophyll-a concentration estimation. The results showed that the proposed method successfully removed the noisy spatial pattern caused by misregistration while maintaining the original spatial resolution for both homogeneous scenes and an episodic scene with a red tide outbreak.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

23

Zhao, Bin, Supeng Wu und Kaiyun Wang. „Quantale algebras as lattice-valued quantales“. Soft Computing 21, Nr. 10 (20.04.2016): 2561–74. http://dx.doi.org/10.1007/s00500-016-2147-5.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

24

Vargas-Herrera, Natalia, Manuel Fernández-Navarro, Nestor E. Cabezudo, Percy Soto-Becerra, Gilmer Solís-Sánchez, Stefan Escobar-Agreda, Javier Silva-Valencia et al. „Immunogenicity and reactogenicity of a third dose of BNT162b2 vaccine for COVID-19 after a primary regimen with BBIBP-CorV or BNT162b2 vaccines in Lima, Peru“. PLOS ONE 17, Nr. 10 (17.10.2022): e0268419. http://dx.doi.org/10.1371/journal.pone.0268419.

Der volle Inhalt der Quelle

Annotation:

Background The administration of a third (booster) dose of COVID-19 vaccines in Peru initially employed the BNT162b2 (Pfizer) mRNA vaccine. The national vaccination program started with healthcare workers (HCW) who received BBIBP-CorV (Sinopharm) vaccine as primary regimen and elderly people previously immunized with BNT162b2. This study evaluated the reactogenicity and immunogenicity of the “booster” dose in these two groups in Lima, Peru. Methods We conducted a prospective cohort study, recruiting participants from November to December of 2021 in Lima, Peru. We evaluated immunogenicity and reactogenicity in HCW and elderly patients previously vaccinated with either two doses of BBIBP-CorV (heterologous regimen) or BTN162b2 (homologous regimen). Immunogenicity was measured by anti-SARS-CoV-2 IgG antibody levels immediately before boosting dose and 14 days later. IgG geometric means (GM) and medians were obtained, and modeled using ANCOVA and quantile regressions. Results The GM of IgG levels increased significantly after boosting: from 28.5±5.0 AU/mL up to 486.6±1.2 AU/mL (p<0.001) which corresponds to a 17-fold increase. The heterologous vaccine regimen produced higher GM of post-booster anti-SARS-CoV-2 IgG levels, eliciting a 13% increase in the geometric mean ratio (95%CI: 1.02–1.27) and a median difference of 92.3 AU/ml (95%CI: 24.9–159.7). Both vaccine regimens were safe and well tolerated. Previous COVID-19 infection was also associated with higher pre and post-booster IgG GM levels. Conclusion Although both boosting regimens were highly immunogenic, two doses of BBIBP-CorV boosted with BTN162b2 produced a stronger IgG antibody response than the homologous BNT162b2 regimen in the Peruvian population. Additionally, both regimens were mildly reactogenic and well-tolerated.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

25

Mazorra-Aguiar, Luis, Philippe Lauret, Mathieu David, Albert Oliver und Gustavo Montero. „Comparison of Two Solar Probabilistic Forecasting Methodologies for Microgrids Energy Efficiency“. Energies 14, Nr. 6 (18.03.2021): 1679. http://dx.doi.org/10.3390/en14061679.

Der volle Inhalt der Quelle

Annotation:

In this paper, the performances of two approaches for solar probabilistic are evaluated using a set of metrics previously tested by the meteorology verification community. A particular focus is put on several scores and the decomposition of a specific probabilistic metric: the continuous rank probability score (CRPS) as they give extensive information to compare the forecasting performance of both methodologies. The two solar probabilistic forecasting methodologies are used to produce intra-day solar forecasts with time horizons ranging from 1 h to 6 h. The first methodology is based on two steps. In the first step, we generated a point forecast for each horizon and in a second step, we use quantile regression methods to estimate the prediction intervals. The second methodology directly estimates the prediction intervals of the forecasted clear sky index distribution using past data as inputs. With this second methodology we also propose to add solar geometric angles as inputs. Overall, nine probabilistic forecasting performances are compared at six measurements stations with different climatic conditions. This paper shows a detailed picture of the overall performance of the models and consequently may help in selecting the best methodology.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

26

Vojtek, Matej, Jana Vojteková und Quoc Bao Pham. „GIS-Based Spatial and Multi-Criteria Assessment of Riverine Flood Potential: A Case Study of the Nitra River Basin, Slovakia“. ISPRS International Journal of Geo-Information 10, Nr. 9 (27.08.2021): 578. http://dx.doi.org/10.3390/ijgi10090578.

Der volle Inhalt der Quelle

Annotation:

The aim of this study was to identify the areas with different levels of riverine flood potential (RFP) in the Nitra river basin, Slovakia, using multi-criteria evaluation (MCE)-analytical hierarchical process (AHP), geographic information systems (GIS), and seven flood conditioning factors. The RFP in the Nitra river basin had not yet been assessed through MCE-AHP. Therefore, the methodology used can be useful, especially in terms of the preliminary flood risk assessment required by the EU Floods Directive. The results showed that classification techniques of natural breaks (Jenks), equal interval, quantile, and geometric interval classified 32.03%, 29.90%, 41.84%, and 53.52% of the basin, respectively, into high and very high RFP while 87.38%, 87.38%, 96.21%, and 98.73% of flood validation events, respectively, corresponded to high and very high RFP. A single-parameter sensitivity analysis of factor weights was performed in order to derive the effective weights, which were used to calculate the revised riverine flood potential (RRFP). In general, the differences between the RFP and RRFP can be interpreted as an underestimation of the share of high and very high RFP as well as the share of flood events in these classes within the RFP assessment. Therefore, the RRFP is recommended for the assessment of riverine flood potential in the Nitra river basin.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

27

Lu, Wei, Zhuo Sun, Zhengyuan Wang, Mengying Qu, Zehuan Shi, Qi Song, Liping Shen et al. „The Joint Effects of Bisphenols and Iodine Exposure on Thyroid during Pregnancy“. Nutrients 15, Nr. 15 (02.08.2023): 3422. http://dx.doi.org/10.3390/nu15153422.

Der volle Inhalt der Quelle

Annotation:

The aim of this research was to study the combined effects of bisphenols and iodine exposure on the thyroid gland during pregnancy. We included 162 pregnant women from a cohort established in Shanghai. Urinary concentrations of bisphenol A, bisphenol B(BPB), bisphenol C(BPC), bisphenol F, bisphenol S, and bisphenol AF(BPAF) were examined. Bayesian kernel machine regression (BKMR) and quantile g-computation models were used. The geometric means of BPA, BPB, BPC, BPF, BPS, BPAF, and ΣBPs levels in urine were 3.03, 0.24, 2.66, 0.36, 0.26, 0.72, and 7.55 μg/g creatinine, respectively. We observed a positive trend in the cumulative effects of BPs and iodine on serum triiodothyronine (FT3) and free thyroxine (FT4), as well as a U-shaped dose–response relationship between BPs and the probability of occurrence of thyroperoxidase autoantibody positivity in women with low urinary iodine concentration. In addition, a synergistic effect on the probability of occurrence of thyroid autoantibody positivity was observed between BPF and BPB, as well as between BPC and BPAF in this study. There were adverse health effects on the thyroid after co-exposure to BPs and iodine. Even if pregnant women were exposed to lower levels of BPs, women with iodine deficiency remained vulnerable to thyroid autoimmune disease.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

28

Zayed, Mohammad A., Amal S. Hassan, Ehab M. Almetwally, Ahmad M. Aboalkhair, Abdullah H. Al-Nefaie und Hisham M. Almongy. „A Compound Class of Unit Burr XII Model: Theory, Estimation, Fuzzy, and Application“. Scientific Programming 2023 (26.04.2023): 1–17. http://dx.doi.org/10.1155/2023/4509889.

Der volle Inhalt der Quelle

Annotation:

The current research offers an enhanced three-parameter lifetime model that combines the unit Burr XII distribution with a power series distribution. The novel class of distribution is named the unit Burr XII power series (UBXIIPS). This compounding technique allows for the production of flexible distributions with strong physical meanings in domains such as biology and engineering. The UBXIIPS class includes the unit Burr XII Poisson (UBXIIP) distribution, the unit Burr XII binomial distribution, the unit Burr XII geometric distribution, and the unit Burr XII negative binomial distribution. The statistical properties of the class include formulas for the density and cumulative distribution functions, and limiting behaviour, moments and incomplete moments, entropy measures, and quantile function are provided. For estimating population parameters and fuzzy reliability for the UBXIIP model, maximum likelihood and Bayesian approaches are studied by the Metropolis–Hastings algorithm. For maximum likelihood estimators, the length of asymptotic confidence intervals is specified, whereas, for Bayesian estimators, the length of credible confidence intervals is assigned. A simulation investigation of the UBXIIP model was established to evaluate the performance of suggested estimates. In addition, the UBXIIP distribution is explored using real-world data. The UBXIIP distribution appears to offer some benefits in understanding lifetime data when compared to unit Weibull, beta, Kumaraswamy, Kumaraswamy Kumaraswamy, Marshall-Olkin Kumaraswamy, and Topp–Leone Weibull Lomax distributions.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

29

VASILCA, Doina. „How to Create an Effective Thematic Map“. Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca. Horticulture 76, Nr. 2 (19.11.2019): 258. http://dx.doi.org/10.15835/buasvmcn-hort:2019.0035.

Der volle Inhalt der Quelle

Annotation:

Considering the evolution of automatic mapping programs and the huge amount of available data, the key elements that go into creating thematic maps are presented so that those less familiar with map-making might be able to craft accurate, reliable and illustrative maps.Here, we used ArcGIS Pro in order to exemplify the process of creating thematic maps presenting correlations between the number of emergency/total 112 calls and the population of Romanian counties. These freely-available data were classified using Natural Brakes, Quantile, Equal Interval, Geometric Interval, Standard Deviation, Defined Interval and Manual Interval, so as to highlight their relevant aspects. The value of the goodness of absolute deviation fit was calculated for each method and each data set. The maps were then created using combined choropleth and proportional symbol methods. The ratio between the total number of 112 calls and the county populations, structured into five classes, has been represented using choropleth method. On the resulting map, emergency calls have been represented with proportional symbols. Furthermore, aspects related to the other map elements were presented all in one place, in order to create a thematic map that would be easy to understand and interpret.The findings of the present paper could be used by those who want to represent their own data in a very suggestive and reliable manner, without having had any cartographic training beforehand. They could also more easily interpret their datasets and be able to take the necessary steps in their own domains of activity.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

30

Astakhova, Tatiyana, Nataliya Verzun, Viktor Kasatkin, Mikhail Kolbanev und Aleksey Shamin. „Sensor network connectivity models“. Information and Control Systems, Nr. 5 (17.10.2019): 38–50. http://dx.doi.org/10.31799/1684-8853-2019-5-38-50.

Der volle Inhalt der Quelle

Annotation:

Introduction: One of the key areas in the research of wireless sensor networks is studying the ways to increase the battery lifeby saving energy in individual devices. The article introduces and discusses a new energy-efficient stochastic measure of the qualityparameter for a wireless sensor network – connectivity, which reflects the ability of a network to establish connections betweenits elements within the boundaries of the sensor field in real time, at a certain level of the sensor device battery charge. Purpose:Identifying the interdependence between the probability-time and probability-energy characteristics, as well as the influence, on thesecharacteristics, of such parameters as geometric dimensions, distribution model of sensor devices within the sensor field, networktopology and message routing algorithms. Results: A new stochastic characteristic of wireless sensor network functioning quality isproposed, called connectivity. It encompasses the spatial, temporal and energy characteristics of the network, making it possible todescribe, from a general point of view, a wide range of problems which arise when you study the functioning of wireless networksat the stages of data collecting, distributing and processing by the sensors. Stochastic connectivity indicators are introduced forwireless sensor networks, describing a network as a whole and allowing you to investigate the delay and blocking of the informationexchange, taking into account the size of the sensor field and the power consumed by individual devices. Models are built for assessingthe probability of wireless sensor network connectivity, message delivery time and delivery time quantile, improving the accuracyof network quality assessments. Practical relevance: The obtained models and methods are supposed to be used in digitalization ofagricultural organizations and in the educational process at Knyagininsky University.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

31

Koechlin, Luca, Urs Zenklusen, Thomas Doebele, Bejtush Rrahmani, Brigitta Gahl, Thibault Schaeffer, Denis Berdajs, Friedrich S. Eckstein und Oliver Reuthebuch. „Analysis of Myocardial Ischemia Parameters after Coronary Artery Bypass Grafting with Minimal Extracorporeal Circulation and a Novel Microplegia versus Off-Pump Coronary Artery Bypass Grafting“. Mediators of Inflammation 2020 (25.01.2020): 1–8. http://dx.doi.org/10.1155/2020/5141503.

Der volle Inhalt der Quelle

Annotation:

Background. To compare the performance of our institutionally refined microplegia protocol in conjunction with minimal extracorporeal circulation system (MiECC) with off-pump coronary artery bypass grafting (OPCAB). Methods. We conducted a single center study including patients undergoing isolated CABG surgery performed either off-pump or on-pump using our refined microplegia protocol in conjunction with MiECC. We used propensity modelling to calculate the inverse probability of treatment weights (IPTW). Primary endpoints were peak values of high-sensitivity cardiac troponin T (hs-cTnT) during hospitalization, and respective first values on the first postoperative day. Endpoint analysis was adjusted for intraoperative variables. Results. After IPTW, we could include 278 patients into our analyses, 153 of which had received OPCAB and 125 of which had received microplegia. Standardized differences indicated that treatment groups were comparable after IPTW. The multivariable quantile regression yielded a nonsignificant median increase of first hs-cTnT by 39 ng/L (95% CI -8 to 87 ng/L, p=0.11), and of peak hs-cTnT by 35 ng/L (CI -13 to 84, p=0.16), when microplegia was used, as compared to OPCAB. Major adverse cardiac and cerebrovascular events (MACCE) occurred with equal frequency in both groups (7.8% vs. 5.0%; p=0.51), and length of stay in the intensive care unit (ICU) was significantly shorter after the use of microplegia (geometric mean 1.6 days versus 1.3 days; p=0.01). Conclusion. The use of our institutionally refined microplegia in conjunction with MiECC was associated with similar results with regard to ischemic injury, expressed in hs-cTnT compared to OPCAB. MACCE was seen equally frequent. ICU discharge was earlier if microplegia was used.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

32

Balabushkin, Aleksander. „Approximation to portfolio liquidation value with calculation of its skewness“. Economics and the Mathematical Methods 59, Nr. 1 (2023): 105. http://dx.doi.org/10.31857/s042473880024878-4.

Der volle Inhalt der Quelle

Annotation:

A boundary problem for a homogeneous multidimensional diffusion process is considered under the assumption of small perturbations. Approximations to the mean, second and third central moments of the process at the moment of the first crossing a given plane in phase space are presented as a solution of ordinary differential equations with an additional transformation (“projection onto the boundary”). The quantile of a linear combination of coordinates is estimated by the second order expansion in powers of a small parameter determining the magnitude of perturbations. In the first approximation, this expansion corresponds to the Gaussian distribution, the next term contains skewness. The result is extended to a process with multiple boundaries, upon reaching each of them the equation of the process changes. Such a model describes the liquidation of a portfolio of financial instruments in which the closing rate of each of the positions is a random process. The result is illustrated by two examples. In the first example a portfolio consists of linear instruments (such as stocks, futures), prices are correlated Geometric Brownian Motions with zero drift. The closing rates are constant, but with random noise due to daily fluctuations in trading volume. In this particular case approximations for the mean, variance, skewness, VaR and CVaR of the financial result of portfolio liquidation are given explicitly. In the second example, the liquidation of an exchange-traded option position is considered under the assumption that the closing rate depends on the ratio of the underlying price to the strike of the option. Numerical calculations demonstrate that taking into account skewness significantly increases the accuracy of estimates.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

33

Ristl, Robin, Johannes Klopf, Andreas Scheuba, Florian Wolf, Martin Funovics, Bernd Gollackner, Anders Wanhainen et al. „Growth prediction model for abdominal aortic aneurysms“. British Journal of Surgery 109, Nr. 2 (28.11.2021): 211–19. http://dx.doi.org/10.1093/bjs/znab407.

Der volle Inhalt der Quelle

Annotation:

Abstract Background The most relevant determinant in scheduling monitoring intervals for abdominal aortic aneurysms (AAAs) is maximum diameter. The aim of the study was to develop a statistical model that takes into account specific characteristics of AAA growth distributions such as between-patient variability as well as within-patient variability across time, and allows probabilistic statements to be made regarding expected AAA growth. Methods CT angiography (CTA) data from patients monitored at 6-month intervals with maximum AAA diameters at baseline between 30 and 66 mm were used to develop the model. By extending the model of geometric Brownian motion with a log-normal random effect, a stochastic growth model was developed. An additional set of ultrasound-based growth data was used for external validation. Results The study data included 363 CTAs from 87 patients, and the external validation set comprised 390 patients. Internal and external cross-validation showed that the stochastic growth model allowed accurate description of the distribution of aneurysm growth. Median relative growth within 1 year was 4.1 (5–95 per cent quantile 0.5–13.3) per cent. Model calculations further resulted in relative 1-year growth of 7.0 (1.0–16.4) per cent for patients with previously observed rapid 1-year growth of 10 per cent, and 2.6 (0.3–8.3) per cent for those with previously observed slow growth of 1 per cent. The probability of exceeding a threshold of 55 mm was calculated to be 1.78 per cent at most when adhering to the current RESCAN guidelines for rescreening intervals. An online calculator based on the fitted model was made available. Conclusion The stochastic growth model was found to provide a reliable tool for predicting AAA growth.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

34

Chen, Wei, Zhao Wang, Guirong Wang, Zixin Ning, Boxiang Lian, Shangjie Li, Paraskevas Tsangaratos, Ioanna Ilia und Weifeng Xue. „Optimizing Rotation Forest-Based Decision Tree Algorithms for Groundwater Potential Mapping“. Water 15, Nr. 12 (19.06.2023): 2287. http://dx.doi.org/10.3390/w15122287.

Der volle Inhalt der Quelle

Annotation:

Groundwater potential mapping is an important prerequisite for evaluating the exploitation, utilization, and recharge of groundwater. The study uses BFT (best-first decision tree classifier), CART (classification and regression tree), FT (functional trees), EBF (evidential belief function) benchmark models, and RF-BFTree, RF-CART, and RF-FT ensemble models to map the groundwater potential of Wuqi County, China. Firstly, select sixteen groundwater spring-related variables, such as altitude, plan curvature, profile curvature, curvature, slope angle, slope aspect, stream power index, topographic wetness index, stream sediment transport index, normalized difference vegetation index, land use, soil, lithology, distance to roads, distance to rivers, and rainfall, and make a correlation analysis of these sixteen groundwater spring-related variables. Secondly, optimize the parameters of the seven models and select the optimal parameters for groundwater modeling in Wuqi County. The predictive performance of each model was evaluated by estimating the area under the receiver operating characteristic (ROC) curve (AUC) and statistical index (accuracy, sensitivity, and specificity). The results show that the seven models have good predictive capabilities, and the ensemble model has a larger AUC value. Among them, the RF-BFT model has the highest success rate (AUC = 0.911), followed by RF-FT (0.898), RF-CART (0.894), FT (0.852), EBF (0.824), CART (0.801), and BFtree (0.784), respectively. Groundwater potential maps of these 7 models were obtained, and four different classification methods (geometric interval, natural breaks, quantile, and equal interval) were used to reclassify the obtained GPM into 5 categories: very low (VLC), low (LC), moderate (MC), high (HC), and very high (VHC). The results show that the natural breaks method has the best classification performance, and the RF-BFT model is the most reliable. The study highlights that the proposed ensemble model has more efficient and accurate performance for groundwater potential mapping.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

35

Chaudhuri, Probal. „On a Geometric Notion of Quantiles for Multivariate Data“. Journal of the American Statistical Association 91, Nr. 434 (Juni 1996): 862–72. http://dx.doi.org/10.1080/01621459.1996.10476954.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

36

Girard, Stéphane, und Gilles Stupfler. „Extreme geometric quantiles in a multivariate regular variation framework“. Extremes 18, Nr. 4 (01.10.2015): 629–63. http://dx.doi.org/10.1007/s10687-015-0226-0.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

37

'Afifah, Z. N. „EFFECTIVENESS OF CLASSIFICATION METHOD AND COLOR SYMBOL SCHEME ON CHOROPLETH MAP OF POPULATION DENSITY IN SPECIAL REGION OF YOGYAKARTA“. ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-4/W16 (01.10.2019): 55–61. http://dx.doi.org/10.5194/isprs-archives-xlii-4-w16-55-2019.

Der volle Inhalt der Quelle

Annotation:

Abstract. The need for presenting information in maps is increasingly high in various scientific fields. All scientific fields need to present effective data for decision making. Good decision making based on maps requires good understanding but not all scientific fields are familiar with using maps. Supporting factors for easy maps to understand are classification method and color symbol scheme. The purpose of this study was to select and test the classification method and the most effective color symbol scheme for mapping population density in the Special Region of Yogyakarta. The classification methods used in this study are constant interval, arithmetic progression, geometric progression, quantile, standard deviation and dispersal graph. The effectiveness test method for the most effective classification method is the proportion assessment. The color symbol scheme used in this study is a sequential color scheme, diverging color schemes, Corel Draw color schemes and color symbol schemes provided in ArcMap 10.3 software. The effectiveness test method for the most effective color symbol scheme is conventional eye tracking. The results showed that according to the proportion test the most effective classification method was the arithmetic interval classification method with results of 0.26. The most effective color symbol scheme in accordance with the effectiveness test using the conventional eye tracking method shows that the most effective color symbol scheme is a diverging color scheme. The important aspects to consider are average answering duration of 8.15 seconds, the accuracy of the answer is 98.9%, and easiness level of symbolization readings is 341. This research can be one of the references on the most effective classification method and reference regarding the selection of the most effective color symbol scheme on Choropleth Map of Population Density in Special Region of Yogyakarta, so that further research can continue the analysis of appropriate classification methods for demographic data. The method discussed in this study is also expected to be applicable to other data.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

38

Ahmadi, Shukrullah, Barbara Le Bot, Roméo Zoumenou, Séverine Durand, Nadine Fiévet, Pierre Ayotte, Achille Massougbodji et al. „Follow-Up of Elevated Blood Lead Levels and Sources in a Cohort of Children in Benin“. International Journal of Environmental Research and Public Health 17, Nr. 22 (23.11.2020): 8689. http://dx.doi.org/10.3390/ijerph17228689.

Der volle Inhalt der Quelle

Annotation:

Lead exposure is associated with poor cognitive development in children. Very few studies in sub-Saharan Africa (SSA) have studied blood lead levels (BLLs) and non-gasoline sources of exposure in children. Data from a birth cohort in Benin (2011–2013) suggested that 58% of 1-year-old children had BLLs > 50 ug/L. We aimed to investigate the prevalence of elevated BLLs (>50 µg/L and >100 µg /L) among 425 of these children at 6 years of age in 2016–2018 and to compare BLLs between age 1 and 6 years, and study sources of lead at age 6 years. BLLs were analysed by inductively coupled plasma mass spectrometry. Multiple linear regression and quantile regressions were used to study potential sources of lead. The prevalence of BLLs > 50 µg/L in children was 59.5% (Geometric Mean (GM) 56.4 µg/L, 95% CI: 54.1–58.7) at 6 years of age compared to 54.8% (GM 56.5 µg/L, 95% CI: 53.4–59.6) at 1 year of age. The prevalence of children with BLLs > 100 µg/L decreased from 14.4% at 1 year of age to 8.2% at 6 years of age. After adjustment for all other covariates, consumption of peanuts more than once per month was significantly associated with a 22.0% (95% CI: 4.6, 42.5) increment in BLLs at age 6 years compared with no consumption. Consumption of bushmeat killed by lead bullets at age 6 years was associated with an increase in the higher percentiles of BLLs (P75) compared with the absence of this source. Other potential sources of lead associated with BLLs with marginal significance were consumption of rice, paternal occupational exposure, and the presence of activity with the potential use of lead. This prospective cohort confirms the persistently high prevalence of elevated BLLs in children residing in a rural region in the south of Benin, as well as the presence of multiple and continuous sources of lead. These results highlight the need for prevention programs to reduce and eliminate lead exposure in children.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

39

Keevil, Brian G., Soazig Clifton, Clare Tanton, Wendy Macdowall, Andrew J. Copas, David Lee, Nigel Field et al. „Distribution of Salivary Testosterone in Men and Women in a British General Population-Based Sample: The Third National Survey of Sexual Attitudes and Lifestyles (Natsal-3)“. Journal of the Endocrine Society 1, Nr. 1 (01.01.2017): 14–25. http://dx.doi.org/10.1210/js.2016-1029.

Der volle Inhalt der Quelle

Annotation:

Abstract Introduction: Measurement of salivary testosterone (Sal-T) to assess androgen status offers important potential advantages in epidemiological research. The utility of the method depends on the interpretation of the results against robustly determined population distributions, which are currently lacking. Aim: To determine age-specific Sal-T population distributions for men and women. Methods: Morning saliva samples were obtained from participants in the third National Survey of Sexual Attitudes and Lifestyles, a probability sample survey of the British general population. Sal-T was measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Linear and quantile regression analyses were used to determine the age-specific 2.5th and 97.5th percentiles for the general population (1675 men and 2453 women) and the population with health exclusions (1145 men and 1276 women). Results: In the general population, the mean Sal-T level in men decreased from 322.6 pmol/L at 18 years of age to 153.9 pmol/L at 69 years of age. In women, the decrease in the geometric mean Sal-T level was from 39.8 pmol/L at 18 years of age to 19.5 pmol/L at 74 years of age. The annual decrease varied with age, with an average of 1.0% to 1.4% in men and 1.3% to 1.5% in women. For women, the 2.5th percentile fell below the detection limit (<6.5 pmol/L) from age 52 years onward. The mean Sal-T level was approximately 6 times greater in men than in women, and this remained constant over the age range. The Sal-T level was lowest for men and highest for women in the summer. The results were similar for the general population with exclusions. Conclusions: To our knowledge, this is the first study to describe the sex- and age-specific distributions for Sal-T in a large representative population using a specific and sensitive LC-MS/MS technique. The present data can inform future population research by facilitating the interpretation of Sal-T results as a marker of androgen status.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

40

ADESSO, GERARDO, und DAVIDE GIROLAMI. „GAUSSIAN GEOMETRIC DISCORD“. International Journal of Quantum Information 09, Nr. 07n08 (Oktober 2011): 1773–86. http://dx.doi.org/10.1142/s0219749911008192.

Der volle Inhalt der Quelle

Annotation:

We extend the geometric measure of quantum discord, introduced and computed for two-qubit states, to quantify non-classical correlations in composite Gaussian states of continuous variable systems. We lay the formalism for the evaluation of a Gaussian geometric discord in two-mode Gaussian states, and present explicit formulas for the class of two-mode squeezed thermal states. In such a case, under physical constraints of bounded mean energy, geometric discord is shown to admit upper and lower bounds for a fixed value of the conventional (entropic) quantum discord. We finally discuss alternative geometric approaches to quantify Gaussian quadrature correlations.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

41

Sun, Edward W., Yu-Jen Wang und Min-Teh Yu. „Integrated Portfolio Risk Measure: Estimation and Asymptotics of Multivariate Geometric Quantiles“. Computational Economics 52, Nr. 2 (13.06.2017): 627–52. http://dx.doi.org/10.1007/s10614-017-9708-2.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

42

Chaouch, Mohamed, und Camelia Goga. „Design-based estimation for geometric quantiles with application to outlier detection“. Computational Statistics & Data Analysis 54, Nr. 10 (Oktober 2010): 2214–29. http://dx.doi.org/10.1016/j.csda.2010.03.006.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

43

Yamaka, Woraphon, Jianxu Liu, Mingyang Li, Paravee Maneejuk und Hai Q. Dinh. „Analyzing the Causality and Dependence between Exchange Rate and Real Estate Prices in Boom-and-Bust Markets: Quantile Causality and DCC Copula GARCH Approaches“. Axioms 11, Nr. 3 (03.03.2022): 113. http://dx.doi.org/10.3390/axioms11030113.

Der volle Inhalt der Quelle

Annotation:

Unlike most previous studies examining the causal relationship and dependence between exchange rates and real estate prices, this study aims to investigate the causal relationship and dependence between these two variables in a boom-and-bust market setting using the panel quantile Granger causality and dynamic conditional correlation (DCC) copula GARCH approaches, respectively. In the panel quantile Granger causality test, quantiles 0.1 and 0.9 are considered to represent extreme markets (bust and boom, respectively). Our first results showed the causal effects at extreme quantiles to be very different from those at the median quantile. We also found a greater causality between house prices and exchange rates in the boom market compared to the bust market. In the second model, we explored the relationship between exchange rates and real estate prices, taking boom-and-bust dynamics into account by measuring the tail dependence through the DCC copula GARCH method. Our findings confirm the strong time-varying tail dependence between house prices and exchange rates. The degree of tail dependence was quite stable over the sample period, except for the periods around 1997–1998 and 2008–2009, when the degree of tail dependence was stronger and less persistent. These two periods correspond to the two great financial crises in Asia and the USA, respectively.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

44

Hofmann, Dirk, und Paweł Waszkiewicz. „Approximation in quantale-enriched categories“. Topology and its Applications 158, Nr. 8 (Mai 2011): 963–77. http://dx.doi.org/10.1016/j.topol.2011.02.003.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

45

Boyer, D. M., Y. Lipman, E. St. Clair, J. Puente, B. A. Patel, T. Funkhouser, J. Jernvall und I. Daubechies. „Algorithms to automatically quantify the geometric similarity of anatomical surfaces“. Proceedings of the National Academy of Sciences 108, Nr. 45 (24.10.2011): 18221–26. http://dx.doi.org/10.1073/pnas.1112822108.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

46

Almeida, Celeste, João Paulo Guedes, António Arêde und Aníbal Costa. „Geometric indices to quantify textures irregularity of stone masonry walls“. Construction and Building Materials 111 (Mai 2016): 199–208. http://dx.doi.org/10.1016/j.conbuildmat.2016.02.038.

Der volle Inhalt der Quelle

APA, Harvard, Vancouver, ISO und andere Zitierweisen

47

Koç, Tuba, und Haydar Koç. „A New Class of Quantile Regression Ratio-Type Estimators for Finite Population Mean in Stratified Random Sampling“. Axioms 12, Nr. 7 (22.07.2023): 713. http://dx.doi.org/10.3390/axioms12070713.

Der volle Inhalt der Quelle

Annotation:

Quantile regression is one of the alternative regression techniques used when the assumptions of classical regression analysis are not met, and it estimates the values of the study variable in various quantiles of the distribution. This study proposes ratio-type estimators of a population mean using the information on quantile regression for stratified random sampling. The proposed ratio-type estimators are investigated with the help of the mean square error equations. Efficiency comparisons between the proposed estimators and classical estimators are presented in certain conditions. Under these obtained conditions, it is seen that the proposed estimators outperform the classical estimators. In addition, the theoretical results are supported by a real data application.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

48

Wang, Gang, Norden E. Huang, Wei Tai Hsu, Men Tzung Lo, Fang Li Qiao und Min Lin. „Measurement of the Irregular Geometric Shapes“. Applied Mechanics and Materials 152-154 (Januar 2012): 1287–91. http://dx.doi.org/10.4028/www.scientific.net/amm.152-154.1287.

Der volle Inhalt der Quelle

Annotation:

Image presents the basic physical features of an object. Geometry, on the other hand, provides us a powerful way to quantify the information reflected by images or their shapes. Traditional geometry however finds limitation in describing the differences between highly irregular objects，which requires us to find new approaches to measure an object and quantify its difference from another. In this paper, we define some scalars in two dimensions to meet this demand. These approaches, grounded on circularity, convexity and cavity, describe the geometry of shapes in statistic sense, and they can also be applied to qualify the differences of shapes.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

49

Korotimi, Ou´edraogo, und Barro Diakarya. „An Approach of Estimating the Value at Risk of Heavy-tailed Distribution using Copulas“. European Journal of Pure and Applied Mathematics 15, Nr. 4 (31.10.2022): 2074–85. http://dx.doi.org/10.29020/nybg.ejpam.v15i4.4280.

Der volle Inhalt der Quelle

Annotation:

The value at risk (VaR) plays a fundamental role in modeling risk in financial studies. We propose a approach in estimating the VaR for heavy-tailed distribution by taking into account the effects of certain covariates on the variable of interest. This method, involves estimating the extreme conditional quantiles by using the assciated copula. Morever, we use Bernstein copulas to estimate the intermediate conditional quantile in a non-parametric approach of the direct method.Then, the extreme conditional quantile is also estimated and we study the asymptotic properties of this new estimator.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

50

Szőke, Róbert. „Adapted complex structures and geometric quantization“. Nagoya Mathematical Journal 154 (1999): 171–83. http://dx.doi.org/10.1017/s002776300002537x.

Der volle Inhalt der Quelle

Annotation:

AbstractA compact Riemannian symmetric space admits a canonical complexification. This so called adapted complex manifold structure JA is defined on the tangent bundle. For compact rank-one symmetric spaces another complex structure JS is defined on the punctured tangent bundle. This latter is used to quantize the geodesic flow for such manifolds. We show that the limit of the push forward of JA under an appropriate family of diffeomorphisms exists and agrees with JS.

APA, Harvard, Vancouver, ISO und andere Zitierweisen

Zeitschriftenartikel zum Thema „Geometric quantile“

Geben Sie eine Quelle nach APA, MLA, Chicago, Harvard und anderen Zitierweisen an