scholarly journals Statistical Analysis and Machine Learning Prediction of Fog-Caused Low-Visibility Events at A-8 Motor-Road in Spain

Atmosphere ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 679
Author(s):  
Sara Cornejo-Bueno ◽  
David Casillas-Pérez ◽  
Laura Cornejo-Bueno ◽  
Mihaela I. Chidean ◽  
Antonio J. Caamaño ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Probability Distributions ◽  
Pearson Correlation ◽  
Likelihood Method ◽  
Neural Network Approach ◽  
Event Duration ◽  
Full Characterization ◽  
Low Visibility ◽  
Learning Machine ◽  
The Impact

This work presents a full statistical analysis and accurate prediction of low-visibility events due to fog, at the A-8 motor-road in Mondoñedo (Galicia, Spain). The present analysis covers two years of study, considering visibility time series and exogenous variables collected in the zone affected the most by extreme low-visibility events. This paper has then a two-fold objective: first, we carry out a statistical analysis for estimating the fittest probability distributions to the fog event duration, using the Maximum Likelihood method and an alternative method known as the L-moments method. This statistical study allows association of the low-visibility depth with the event duration, showing a clear relationship, which can be modeled with distributions for extremes such as Generalized Extreme Value and Generalized Pareto distributions. Second, we apply a neural network approach, trained by means of the ELM (Extreme Learning Machine) algorithm, to predict the occurrence of low-visibility events due to fog, from atmospheric predictive variables. This study provides a full characterization of fog events at this motor-road, in which orographic fog is predominant, causing important traffic problems during all year. We also show how the ELM approach is able to obtain highly accurate low-visibility events predictions, with a Pearson correlation coefficient of 0.8, within a half-hour time horizon, enough to initialize some protocols aiming at reducing the impact of these extreme events in the traffic of the A-8 motor road.

scholarly journals Thematic Maps of the Impact of Urbanization and Socioeconomic Factors on the Distribution of the Incidence of Cutaneous Leishmaniasis Cases in Sefrou Province, Central North of Morocco (2007–2011)

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Fatima Zahra Talbi ◽  
Nordine Nouayti ◽  
Hajar El Omari ◽  
Mohamed Najy ◽  
Khadija Lahouiti ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Socioeconomic Factors ◽  
Cutaneous Leishmaniasis ◽  
Rural Areas ◽  
Urban Areas ◽  
Pearson Correlation ◽  
Correlation Study ◽  
Poverty Rate ◽  
Impact Of Urbanization ◽  
The Impact

Background. Leishmaniases are vector-borne diseases with health risks. They cause a big health problem. These parasitic diseases are transmitted by the parasite of the genus Leishmania through sandflies. Objective. The aim of this work is to study the distribution of the incidence of cutaneous leishmaniasis (CL) cases and the impact of urbanization and socioeconomic factors and their effects as leishmaniasis risk factors. Methods. We conducted a retrospective study of CL cases collected at the level of Sefrou Province during the period from 2007 to 2011. The data was collected from registers of the Medical Delegation of Sefrou Province. The socioeconomic data, namely, the poverty rate, the popular density, and the type of environment (urban/rural) of Sefrou Province, were obtained from the High Commission for Planning. Statistical analysis was performed by SPSS software (version 20). The data were registered in a Microsoft Excel 2010 file. Statistical analysis was based on one-way analysis of variance (ANOVA), and then a correlation study was carried out (Pearson correlation). The results were considered significant when p was less than 0.05. The database was analyzed by QGIS 2.18, which is open source software. Results. A total of 349 cases of CL were collected at Sefrou Province from 2007 to 2011. A percentage of 49% of the cases come from urban areas, while 51% of the cases come from rural areas. In the statistical analysis, the division of the incidence of CL cases was found to be significantly associated only with urbanization. For the other factors, the number of people or the poverty rate is not taken into account in the incidence dynamics. Conclusion. This study may be useful for the implementation of future adequate measures and controls. Getting rid of leishmaniasis requires a comprehensive approach by acting on the sources of contamination through good continuous surveillance, appropriate management, effective vector control, and awareness-raising strategies.

Asteroid and Comet Impact Speeds upon Mars: Significance for Panspermia and the Supply of Organics

1997 ◽  
Vol 161 ◽  
pp. 197-201 ◽  
Author(s):  
Duncan Steel
Keyword(s):  
Probability Distributions ◽  
Regions Of Interest ◽  
Significant Fraction ◽  
Organic Chemicals ◽  
Impact Speed ◽  
The Mean ◽  
The Impact

AbstractWhilst lithopanspermia depends upon massive impacts occurring at a speed above some limit, the intact delivery of organic chemicals or other volatiles to a planet requires the impact speed to be below some other limit such that a significant fraction of that material escapes destruction. Thus the two opposite ends of the impact speed distributions are the regions of interest in the bioastronomical context, whereas much modelling work on impacts delivers, or makes use of, only the mean speed. Here the probability distributions of impact speeds upon Mars are calculated for (i) the orbital distribution of known asteroids; and (ii) the expected distribution of near-parabolic cometary orbits. It is found that cometary impacts are far more likely to eject rocks from Mars (over 99 percent of the cometary impacts are at speeds above 20 km/sec, but at most 5 percent of the asteroidal impacts); paradoxically, the objects impacting at speeds low enough to make organic/volatile survival possible (the asteroids) are those which are depleted in such species.

Assessment of small businesses activities in Ukraine

2019 ◽  
pp. 40-47
Author(s):  
Igor Ponomarenko ◽  
Kateryna Volovnenko
Keyword(s):  
Comparative Analysis ◽  
Statistical Analysis ◽  
Small Business ◽  
Small Businesses ◽  
Government Agencies ◽  
Small Enterprises ◽  
The Subject ◽  
Business Entities ◽  
The Impact ◽  
Micro Enterprises

The subject of the research is a set of approaches to the statistical analysis ofthe activities of small business entities in Ukraine, including micro-enterprises. The purpose of writing this article is to study of the features of functioningof small business entities in Ukraine. Methodology. The research methodology isto use a system-structural and comparative analysis (to study the change in thenumber of small enterprises by major components); monographic (when studyingmethods of statistical analysis of small businesses); economic analysis (when assessing the impact of small business entities on socio-economic phenomena andprocesses in Ukraine). The scientific novelty consists to determine the features ofthe functioning of small businesses in Ukraine in modern conditions. The influenceof the activities of the main socio-economic and political indicators on the activities of small enterprises in recent periods of time has been identified. It has beenestablished that there is flexibility in the development of strategies by small businesses in conditions of significant competition, which makes it possible to quicklyrespond to changing situations in specific markets. Conclusions. The use of acomprehensive statistical analysis of small businesses functioning in Ukraine willallow government agencies to develop a set of measures to optimize the activitiesof these enterprises, which ultimately will positively affect the strengthening oftheir competitiveness and will contribute to the growth of the national economicsystem.

Effects of Quarantine Due to the COVID-19 on Sleep Duration and Quality in Algerians

2020 ◽  
Vol 60 (2) ◽  
pp. 182-193
Author(s):  
Kacem Abdelhadi ◽  
Houar Abdelatif ◽  
Zerf Mohamed ◽  
Bengoua Ali
Keyword(s):  
Statistical Analysis ◽  
Sleep Quality ◽  
Sleep Duration ◽  
Online Survey ◽  
Public Awareness ◽  
Italian Version ◽  
Sleep Timing ◽  
Algerian Population ◽  
Significant Change ◽  
The Impact

SummaryThis study tests the impact of COVID-19 on sleep of Algerian population before and during the COVID-19 quarantine by an estimated online survey, adapted from the PSQI Italian version. Including 1210 participants (age between 18-60 years old). The statistical analysis was carried out using SPSS version 22.0 software. Our results showed a significant change in sleeping quality during quarantine, the sleep timing markedly changed, we also noticed additional use of sleeping medications. Algerian scientists recommend to build public awareness and to provide necessary information regarding Algerian sleep quality, especially for Algerian adults.

The Effect of Public Office Values on Government Trust: Focusing on the Effects of Regulating the Level of Citizenship

2019 ◽  
Vol 118 (2) ◽  
pp. 35-42
Author(s):  
Nam-Sik Yun ◽  
Seok-Kee Lee
Keyword(s):  
Statistical Analysis ◽  
Public Administration ◽  
Public Service ◽  
Public Office ◽  
Institute Of Public Administration ◽  
Service Value ◽  
Korean Government ◽  
Government Sector ◽  
The Impact

Background/Objectives: The study discussed the impact of citizens' perceptions of public office values of integrity, accountability, and fairness, based on the view that government trust is centered on the citizens' perception of the value of public office.  Methods/Statistical analysis: The data was based on a 2017 survey conducted by the Korea Institute of Public Administration on the perception of corruption in the Korean government sector. The study included 1,000 people and was conducted through a survey public service value, citizenship level and government trust. The data were analyzed using the SPSS 22 and AMOS 22.0 program.

The Effect of Public Office Values on Government Trust: Focusing on the Effects of Regulating the Level of Citizenship

2019 ◽  
Vol 118 (8) ◽  
pp. 366-374
Author(s):  
Nam-Sik Yun ◽  
Seok-Kee Lee
Keyword(s):  
Statistical Analysis ◽  
Public Administration ◽  
Public Service ◽  
Public Office ◽  
Institute Of Public Administration ◽  
Service Value ◽  
Korean Government ◽  
Government Sector ◽  
The Impact

The study discussed the impact of citizens' perceptions of public office values of integrity, accountability, and fairness, based on the view that government trust is centered on the citizens' perception of the value of public office. Methods/Statistical analysis: The data was based on a 2017 survey conducted by the Korea Institute of Public Administration on the perception of corruption in the Korean government sector. The study included 1,000 people and was conducted through a survey public service value, citizenship level and government trust. The data were analyzed using the SPSS 22 and AMOS 22.0 program.

scholarly journals Image Statistics Preserving Encrypt-then-Compress Scheme Dedicated for JPEG Compression Standard

Entropy ◽  
2021 ◽  
Vol 23 (4) ◽  
pp. 421
Author(s):  
Dariusz Puchala ◽  
Kamil Stokfiszewski ◽  
Mykhaylo Yatsymirskyy
Keyword(s):  
Statistical Analysis ◽  
Image Encryption ◽  
Experimental Studies ◽  
Quality Measures ◽  
Input Image ◽  
Jpeg Compression ◽  
Image Statistics ◽  
Compression Stage ◽  
Wide Range ◽  
The Impact

In this paper, the authors analyze in more details an image encryption scheme, proposed by the authors in their earlier work, which preserves input image statistics and can be used in connection with the JPEG compression standard. The image encryption process takes advantage of fast linear transforms parametrized with private keys and is carried out prior to the compression stage in a way that does not alter those statistical characteristics of the input image that are crucial from the point of view of the subsequent compression. This feature makes the encryption process transparent to the compression stage and enables the JPEG algorithm to maintain its full compression capabilities even though it operates on the encrypted image data. The main advantage of the considered approach is the fact that the JPEG algorithm can be used without any modifications as a part of the encrypt-then-compress image processing framework. The paper includes a detailed mathematical model of the examined scheme allowing for theoretical analysis of the impact of the image encryption step on the effectiveness of the compression process. The combinatorial and statistical analysis of the encryption process is also included and it allows to evaluate its cryptographic strength. In addition, the paper considers several practical use-case scenarios with different characteristics of the compression and encryption stages. The final part of the paper contains the additional results of the experimental studies regarding general effectiveness of the presented scheme. The results show that for a wide range of compression ratios the considered scheme performs comparably to the JPEG algorithm alone, that is, without the encryption stage, in terms of the quality measures of reconstructed images. Moreover, the results of statistical analysis as well as those obtained with generally approved quality measures of image cryptographic systems, prove high strength and efficiency of the scheme’s encryption stage.

Data and visual displays in the Journal of Ecology 1996–2016

2020 ◽  
pp. 147387162098012
Author(s):  
Alon Friedman
Keyword(s):  
Best Practices ◽  
Pearson Correlation ◽  
Single Species ◽  
Data Type ◽  
Reliability Test ◽  
Visual Displays ◽  
Domain Type ◽  
Academic Publications ◽  
The Creation ◽  
The Impact

Scholars in scientific disciplines face unique challenges in the creation of visualizations, especially in publications that require insights derived from analyses to be visually displayed. The literature on visualizations describes different techniques and best practices for the creation of graphs. However, these techniques have not been used to evaluate the impact of visualizations in academic publications. In the field of ecology, as in other scientific fields, graphs are an essential part of journal articles. Little is known about the connections between the kind of data presented and domain in which the researchers conducted their study that together produces the visual graphics. This study focused on articles published in the Journal of Ecology between 1996 and 2016 to explore possible connections between data type, domain, and visualization type. Specifically, this study asked three questions: How many of the graphics published between 1996 and 2016 follow a particular set of recommendations for best practices? What can Pearson correlations reveal about the relationships between type of data, domain of study, and visual displays? Can the findings be examined through an inter-reliability test lens? Out of the 20,080 visualizations assessed, 54% included unnecessary graphical elements in the early part of the study (1996–2010). The most common type of data was univariate (35%) and it was often displayed using line graphs. Twenty-one percent of the articles in the period studied could be categorized under the domain type “single species.” Pearson correlation analysis showed that data type and domain type was positively correlated ( r = 0.08; p ≤ 0.05). Cohen’s kappa for the reliability test was 0.86, suggesting good agreement between the two categories. This study provides evidence that data type and domain types are equally important in determining the type of visualizations found in scientific journals.

Validating the impact of accounting disclosures on stock market: A deep neural network approach

2021 ◽  
Vol 170 ◽  
pp. 120903
Author(s):  
Prajwal Eachempati ◽  
Praveen Ranjan Srivastava ◽  
Ajay Kumar ◽  
Kim Hua Tan ◽  
Shivam Gupta
Keyword(s):  
Neural Network ◽  
Stock Market ◽  
Deep Neural Network ◽  
Network Approach ◽  
Neural Network Approach ◽  
Accounting Disclosures ◽  
The Impact

scholarly journals Towards Including Dynamic Vegetation Parameters in the EUMETSAT H SAF ASCAT Soil Moisture Products

2021 ◽  
Vol 13 (8) ◽  
pp. 1463
Author(s):  
Susan C. Steele-Dunne ◽  
Sebastian Hahn ◽  
Wolfgang Wagner ◽  
Mariette Vreugdenhil
Keyword(s):  
Soil Moisture ◽  
Interannual Variability ◽  
Incidence Angle ◽  
Pearson Correlation ◽  
The United States ◽  
Research Network ◽  
Window Width ◽  
High Frequency Variability ◽  
Vegetation Parameters ◽  
The Impact

The TU Wien Soil Moisture Retrieval (TUW SMR) approach is used to produce several operational soil moisture products from the Advanced Scatterometer (ASCAT) on the Metop series of satellites as part of the EUMETSAT Satellite Application Facility on Support to Operational Hydrology and Water Management (H SAF). The incidence angle dependence of backscatter is described by a second-order Taylor polynomial, the coefficients of which are used to normalize ASCAT observations to the reference incidence angle of 40∘ and for correcting vegetation effects. Recently, a kernel smoother was developed to estimate the coefficients dynamically, in order to account for interannual variability. In this study, we used the kernel smoother for estimating these coefficients, where we distinguished for the first time between their two uses, meaning that we used a short and fixed window width for the backscatter normalisation while we tested different window widths for optimizing the vegetation correction. In particular, we investigated the impact of using the dynamic vegetation parameters on soil moisture retrieval. We compared soil moisture retrievals based on the dynamic vegetation parameters to those estimated using the current operational approach by examining their agreement, in terms of the Pearson correlation coefficient, unbiased RMSE and bias with respect to in situ soil moisture. Data from the United States Climate Research Network were used to study the influence of climate class and land cover type on performance. The sensitivity to the kernel smoother half-width was also investigated. Results show that estimating the vegetation parameters with the kernel smoother can yield an improvement when there is interannual variability in vegetation due to a trend or a change in the amplitude or timing of the seasonal cycle. However, using the kernel smoother introduces high-frequency variability in the dynamic vegetation parameters, particularly for shorter kernel half-widths.

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