Practical Dynamical-Statistical Reconstruction of Ocean’s Interior from Satellite Observations

The algorithms based on Surface Quasi-Geostrophic (SQG) dynamics have been developed and validated by many researchers through model products, however it is still doubtful whether these SQG-based algorithms are worth using in terms of observed data. This paper analyzes the factors impeding the practical application of SQG and makes amends by a simple “first-guess (FG) framework”. The proposed framework includes the correction of satellite salinity and the estimation of the FG background, making the SQG-based algorithms applicable in realistic circumstances. The dynamical-statistical method SQG-mEOF-R is thereafter applied to satellite data for the first time. The results are compared with two dynamical algorithms, SQG and isQG, and three empirical algorithms, multivariate linear regression (MLR), random forest (RF), and mEOF-R. The validation against Argo profiles showed that the SQG-mEOF-R presents a robust performance in mesoscale reconstruction and outperforms the other five algorithms in the upper layers. It is promising that the SQG-mEOF-R and the FG framework are applicable to operational reconstruction.

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Evaluation of Evaporation from Water Reservoirs in Local Conditions at Czech Republic

Hydrology ◽

10.3390/hydrology8040153 ◽

2021 ◽

Vol 8 (4) ◽

pp. 153

Author(s):

Eva Melišová ◽

Adam Vizina ◽

Martin Hanel ◽

Petr Pavlík ◽

Petra Šuhájková

Keyword(s):

Czech Republic ◽

Random Forest ◽

Linear Regression ◽

Statistical Methods ◽

Stepwise Regression ◽

The Other ◽

Water Reservoirs ◽

Random Forest Regression ◽

Local Conditions ◽

The Difference

Evaporation is an important factor in the overall hydrological balance. It is usually derived as the difference between runoff, precipitation and the change in water storage in a catchment. The magnitude of actual evaporation is determined by the quantity of available water and heavily influenced by climatic and meteorological factors. Currently, there are statistical methods such as linear regression, random forest regression or machine learning methods to calculate evaporation. However, in order to derive these relationships, it is necessary to have observations of evaporation from evaporation stations. In the present study, the statistical methods of linear regression and random forest regression were used to calculate evaporation, with part of the models being designed manually and the other part using stepwise regression. Observed data from 24 evaporation stations and ERA5-Land climate reanalysis data were used to create the regression models. The proposed regression formulas were tested on 33 water reservoirs. The results show that manual regression is a more appropriate method for calculating evaporation than stepwise regression, with the caveat that it is more time consuming. The difference between linear and random forest regression is the variance of the data; random forest regression is better able to fit the observed data. On the other hand, the interpretation of the result for linear regression is simpler. The study introduced that the use of reanalyzed data, ERA5-Land products using the random forest regression method is suitable for the calculation of evaporation from water reservoirs in the conditions of the Czech Republic.

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Interpolation of Instantaneous Air Temperature Using Geographical and MODIS Derived Variables with Machine Learning Techniques

10.20944/preprints201906.0008.v1 ◽

2019 ◽

Author(s):

Marcos Ruiz-Álvarez ◽

Francisco Alonso-Sarría ◽

Francisco Gomariz-Castillo

Keyword(s):

Machine Learning ◽

Support Vector Machine ◽

Random Forest ◽

Linear Regression ◽

Air Temperature ◽

Satellite Data ◽

Multivariate Linear Regression ◽

Machine Learning Algorithms ◽

Machine Learning Techniques ◽

Support Vector

Several methods have been tried to estimate air temperature using satellite imagery. In this paper, the results of two machine learning algorithms, Support Vector Machine and Random Forest, are compared with Multivariate Linear Regression, TVX and Ordinary kriging. Several geographic, remote sensing and time variables are used as predictors. The validation is carried out using four different statistics on a daily basis allowing the use of ANOVA to compare the results. The main conclusion is that Random Forest with residual kriging produces the best results (R$^2$=0.612 $\pm$ 0.019, NSE=0.578 $\pm$ 0.025, RMSE=1.068 $\pm$ 0.027, PBIAS=-0.172 $\pm$ 0.046), whereas TVX produces the least accurate results. The environmental conditions in the study area are not really suited to TVX, moreover this method only takes into account satellite data. On the other hand, regression methods (Support Vector Machine, Random Forest and Multivariate Linear Regression) use several parameters that are easily calculated from a Digital Elevation Model, adding very little difficulty to the use of satellite data alone. The most important variables in the Random Forest Model were satellite temperature, potential irradiation and cdayt, a cosine transformation of the julian day.

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Operational Walking Dynamics of Crowds Modeled with Linear Regression

Transportation Research Record Journal of the Transportation Research Board ◽

10.3141/2623-10 ◽

2017 ◽

Vol 2623 (1) ◽

pp. 90-97

Author(s):

Dorine C. Duives ◽

Winnie Daamen ◽

Serge P. Hoogendoorn

Keyword(s):

Linear Regression ◽

Walking Speed ◽

Simulation Models ◽

Combined Effect ◽

The Other ◽

Pedestrian Flow ◽

Time Headway ◽

Close Proximity ◽

Walking Dynamics ◽

First Time

In this study the influence of interaction characteristics on operational walking dynamics within a crowd—specifically the influence of the distance headway, time headway, angle of sight, angle of interaction, walking speed, and number of pedestrians located nearby on a pedestrian’s change in speed and direction—is investigated. To the authors’ best knowledge, this is the first time that the combined effect of the characteristics of interactions between pedestrians on the operational walking dynamics of pedestrians has been quantified. The walking speed and the number of pedestrians in close proximity were found to influence the adaptation of speed and direction. The other characteristics of the interaction affect either the change in speed (i.e., distance headway and interaction angle) or the change in direction (i.e., time headway and angle of sight). The results of this study strongly indicate that the density experienced by pedestrians is not the only characteristic of the crowd that affects pedestrians’ operational walking dynamics. Consequently, to model crowd movements correctly, the other characteristics of the interaction must also be taken into account in pedestrian flow theory and simulation models.

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Improving the Retrieval of Crop Canopy Chlorophyll Content Using Vegetation Index Combinations

Remote Sensing ◽

10.3390/rs13030470 ◽

2021 ◽

Vol 13 (3) ◽

pp. 470

Author(s):

Qi Sun ◽

Quanjun Jiao ◽

Xiaojin Qian ◽

Liangyun Liu ◽

Xinjie Liu ◽

...

Keyword(s):

Random Forest ◽

Linear Regression ◽

Chlorophyll Content ◽

Satellite Data ◽

Vegetation Indices ◽

Sensor Data ◽

Crop Canopy ◽

Random Forest Regression ◽

Satellite Sensor Data ◽

Satellite Sensor

Estimates of crop canopy chlorophyll content (CCC) can be used to monitor vegetation productivity, manage crop resources, and control disease and pests. However, making these estimates using conventional ground-based methods is time-consuming and resource-intensive when deployed over large areas. Although vegetation indices (VIs), derived from satellite sensor data, have been used to estimate CCC, they suffer from problems related to spectral saturation, soil background, and canopy structure. A new method was, therefore, proposed for combining the Medium Resolution Imaging Spectrometer (MERIS) terrestrial chlorophyll index (MTCI) and LAI-related vegetation indices (LAI-VIs) to increase the accuracy of CCC estimates for wheat and soybeans. The PROSAIL-D canopy reflectance model was used to simulate canopy spectra that were resampled to match the spectral response functions of the MERIS carried on the ENVISAT satellite. Combinations of the MTCI and LAI-VIs were then used to estimate CCC via univariate linear regression, binary linear regression and random forest regression. The accuracy using the field spectra and MERIS data was determined based on field CCC measurements. All the MTCI and LAI-VI combinations for the selected regression techniques resulted in more accurate estimates of CCC than the use of the MTCI alone (field spectra data for soybeans and wheat: R2 = 0.62 and RMSE = 77.10 μg cm−2; MERIS satellite data for soybeans: R2 = 0.24 and RMSE = 136.54 μg cm−2). The random forest regression resulted in better accuracy than the other two linear regression models. The combination resulting in the best accuracy was the MTCI and MTVI2 and random forest regression, with R2 = 0.65 and RMSE = 37.76 μg cm−2 (field spectra data) and R2 = 0.78 and RMSE = 47.96 μg cm−2 (MERIS satellite data). Combining the MTCI and a LAI-VI represents a further step towards improving the accuracy of estimation CCC based on multispectral satellite sensor data.

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Darwin's two competing phylogenetic trees: marsupials as ancestors or sister taxa?

Archives of Natural History ◽

10.3366/anh.2012.0091 ◽

2012 ◽

Vol 39 (2) ◽

pp. 217-233 ◽

Cited By ~ 4

Author(s):

J. David Archibald

Keyword(s):

Fossil Record ◽

Evolutionary Biology ◽

Phylogenetic Trees ◽

Charles Darwin ◽

The Other ◽

Charles Lyell ◽

Single Origin ◽

Molecular Studies ◽

Richard Owen ◽

First Time

Studies of the origin and diversification of major groups of plants and animals are contentious topics in current evolutionary biology. This includes the study of the timing and relationships of the two major clades of extant mammals – marsupials and placentals. Molecular studies concerned with marsupial and placental origin and diversification can be at odds with the fossil record. Such studies are, however, not a recent phenomenon. Over 150 years ago Charles Darwin weighed two alternative views on the origin of marsupials and placentals. Less than a year after the publication of On the origin of species, Darwin outlined these in a letter to Charles Lyell dated 23 September 1860. The letter concluded with two competing phylogenetic diagrams. One showed marsupials as ancestral to both living marsupials and placentals, whereas the other showed a non-marsupial, non-placental as being ancestral to both living marsupials and placentals. These two diagrams are published here for the first time. These are the only such competing phylogenetic diagrams that Darwin is known to have produced. In addition to examining the question of mammalian origins in this letter and in other manuscript notes discussed here, Darwin confronted the broader issue as to whether major groups of animals had a single origin (monophyly) or were the result of “continuous creation” as advocated for some groups by Richard Owen. Charles Lyell had held similar views to those of Owen, but it is clear from correspondence with Darwin that he was beginning to accept the idea of monophyly of major groups.

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RANKING OF FUEL-AIR MIXTURES IN TERMS OF THEIR PROPENSITYTO DEFLAGRATION-TO-DETONATION TRANSITION

PROGRESS IN DETONATION RESEARCH ◽

10.30826/icpcd12a05 ◽

2020 ◽

Author(s):

S. M. FROLOV ◽

◽

V. I. ZVEGINTSEV ◽

V. S. AKSENOV ◽

I. V. BILERA ◽

...

Keyword(s):

Detonation Wave ◽

The Other ◽

Practical Application ◽

Deflagration To Detonation Transition ◽

Other Hand ◽

Pressure Gain Combustion ◽

Reactive Mixture ◽

Detonation Transition ◽

The One ◽

Energy Converting

The term "detonability" with respect to fuel-air mixtures (FAMs) implies the ability of a reactive mixture of a given composition to support the propagation of a stationary detonation wave in various thermodynamic and gasdynamic conditions. The detonability of FAMs, on the one hand, determines their explosion hazards during storage, transportation, and use in various sectors of the economy and, on the other hand, the possibility of their practical application in advanced energy-converting devices operating on detonative pressure gain combustion.

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Sphagnum mosses (Sphagnaceae, Bryophyta) of mires Chefandzar and Masota in North Ossetia (Caucasus)

Novosti sistematiki nizshikh rastenii ◽

10.31111/nsnr/2018.52.2.455 ◽

2018 ◽

Vol 52 (2) ◽

pp. 455-462 ◽

Cited By ~ 2

Author(s):

G. Ya. Doroshina ◽

I. A. Nikolajev

Keyword(s):

Plant Communities ◽

The Other ◽

North Caucasus ◽

Sphagnum Mosses ◽

Greater Caucasus ◽

The North ◽

First Time ◽

North Ossetia

Sphagnum mires on the Greater Caucasus are rare, characterized by the presence of relict plant communities of glacial age and are in a stage of degradation. The study of Sphagnum of Chefandzar and Masota mires is carried out for the first time. Seven species of Sphagnum are recorded. Their distribution and frequency within the North Caucasus are analyzed. Sphagnum contortum, S. platyphyllum, S. russowii, S. squarrosum are recorded for the first time for the study area and for the flora of North Ossetia. The other mosses found in the study area are listed.

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An Epistemological Criticism of Social Entrepreneurship: Is Social Entrepreneurship a Sound Scientific Field of Research

10.31124/advance.7091927.v1 ◽

2018 ◽

Author(s):

Amir Forouharfar

Keyword(s):

Social Entrepreneurship ◽

Social Constructivism ◽

Social Epistemology ◽

American English ◽

Meta Analysis ◽

Research Question ◽

Knowledge Structure ◽

Scientific Field ◽

The Other ◽

First Time

The paper was shaped around the pivotal question: Is SE a sound and scientific field of research? The question has given a critical tone to the paper and has also helped to bring out some of the controversial debates in the realm of SE. The paper was organized under five main discussions to be able to provide a scientific answer to the research question: (1) is “social entrepreneurship” an oxymoron?, (2) the characteristics of SE knowledge, (3) sources of social entrepreneurship knowledge, (4) SE knowledge: structure and limitations and (5) contributing epistemology-making concepts for SE. Based on the sections, the study relied on the relevant philosophical schools of thought in Epistemology (e.g. Empiricism, Rationalism, Skepticism, Internalism vs. Externalism, Essentialism, Social Constructivism, Social Epistemology, etc.) to discuss these controversies around SE and proposes some solutions by reviewing SE literature. Also, to determine the governing linguistic discourse in the realm of SE, which was necessary for our discussion, Corpus of Contemporary American English (COCA) for the first time in SE studies was used. Further, through the study, SE buzzwords which constitute SE terminology were derived and introduced to help us narrowing down and converging the thoughts in this field and demarking the epistemological boundaries of SE. The originality of the paper on one hand lies in its pioneering discussions on SE epistemology and on the other hand in paving the way for a construction of sound epistemology for SE; therefore in many cases after preparing the philosophical ground for the discussions, it went beyond the prevalent SE literature through meta-analysis to discuss the cases which were raised. The results of the study verified previously claimed embryonic pre-paradigmatic phase in SE which was far from a sound and scientific knowledge, although the scholarly endeavors are the harbingers of such a possibility in the future which calls for further mature academic discussion and development of SE knowledge by the SE academia.

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ANALISIS VARIABEL YANG BERPENGARUH TERHADAP KINERJA PERUSAHAAN DI BURSA EFEK INDONESIA

10.31227/osf.io/7vum4 ◽

2019 ◽

Author(s):

SUSENO - SUSENO

Keyword(s):

Linear Regression ◽

Multiple Linear Regression ◽

Stock Exchange ◽

T Test ◽

The Other ◽

Financial Leverage ◽

F Test ◽

Research Results ◽

Independent Variables ◽

Influential Variable

ANALISIS VARIABEL YANG BERPENGARUH TERHADAP KINERJA PERUSAHAAN DI BURSA EFEK INDONESIAOleh : Suseno STIE SATRIA Purwokerto ABSTRACT The aims of the research are (1) to analyze influence of age, scale, financial leverage, and profitability to performance of firms at The Indonesian Stock Exchange. (2) to determine the most influential variable on the performance of the firms. Hypotheses proposed in this research were: (1) Age, Scales, Financial Leverage, Profitability influences the performance of firms, (2) Age influences the performance of firms, (3) Scales influences the performance of firms, (4) Financial Leverage influences the performance of firms, (5) Profitability influences the performance of firms. Instrument of analysis employed in the research was multiple linear regression with t test and F test.The results of analyses of t test showed that profitability did not influence the performance of the firms. It was indicated by the value of computed t which was smaller than the value of t table. Meanwhile, the t test of age, scale and financial leverage indicated that the value of computed t > t table. It means that these variables (scale and financial leverage) influenced the performance of the firms. The F test showed that the independent variables of age, scale, financial leverage and profitability as a whole significantly influenced the performance of the firms. It was indicated by the calculated F > the value of F table, the value the age computed t which was smaller than the value of -t table..Based on the research results that age and profitability do not influence the performance of the firms, it is suggested that investors should not pay any attention to those variables. On the other hand, they should pay attention to the variables of scale and financial leverage. It is recommended that for further research should include longer periode of the sample.

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A Nabatean port on the Red Sea: note on the pottery finds from al-Qusayr (al-Wajh, Saudi Arabia)

10.31338/uw.2083-537x.pam29.1.23 ◽

2020 ◽

Author(s):

Caroline Durand

Keyword(s):

Saudi Arabia ◽

19Th Century ◽

Red Sea ◽

Point Of View ◽

The Other ◽

Trade Routes ◽

Other Hand ◽

Roman Egypt ◽

Pottery Sherds ◽

First Time

Al-Qusayr is located 40 km south of modern al-Wajh, roughly 7 km from the eastern Red Sea shore. This site is known since the mid-19th century, when the explorer R. Burton described it for the first time, in particular the remains of a monumental building so-called al-Qasr. In March 2016, a new survey of the site was undertaken by the al-‘Ula–al-Wajh Survey Project. This survey focused not only on al-Qasr but also on the surrounding site corresponding to the ancient settlement. A surface collection of pottery sherds revealed a striking combination of Mediterranean and Egyptian imports on one hand, and of Nabataean productions on the other hand. This material is particularly homogeneous on the chronological point of view, suggesting a rather limited occupation period for the site. Attesting contacts between Mediterranean merchants, Roman Egypt and the Nabataean kingdom, these new data allow a complete reassessment of the importance of this locality in the Red Sea trade routes during antiquity.

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