Application of an analytical formula for UV Index reconstructions for two locations in Southwestern Spain

It is suggested that for some transition metal hexahalo complexes, the Eg-(a1g + eg) vibronic coupling model is better suited than the classical T2g-(a1g + eg) model. For the former, alternative model, the potential constants in the analytical formula are evaluated from the numerical map of the adiabatic potential surface by using the linear regression method. The numerical values for 29 hexahalo complexes of the 1st row transition metals are obtained by the CNDO/2 method. Some interesting trends of parameters of such Jahn-Teller-active systems are disclosed.

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Über den Mechanismus der Bildung von Polyanionen in wäßriger Lösung. Zum Bildungsmechanismus eines Polytetramolybdations [Mo4O144-]n / On the Mechanism of Formation of Polyanions in Aqueous Solution. Concerning the Mechanism of Formation of a Polytetramolybdate Ion [Mo4O144-]n

Zeitschrift für Naturforschung B ◽

10.1515/znb-1976-0607 ◽

1976 ◽

Vol 31 (6) ◽

pp. 737-748 ◽

Cited By ~ 5

Author(s):

Karl-Heinz Tytko

Keyword(s):

Aqueous Solution ◽

Coordination Sphere ◽

Analytical Formula ◽

Reaction Pathways ◽

Mechanism Of Formation ◽

X Ray ◽

Theoretical Considerations

Possible structures and the pertinent reaction pathways for the polymetalate ion present in a slightly soluble polymetalate having the analytical formula A2O · 2 MOs have been derived on the basis of theoretical considerations. Structure and kind of combination of the tetrameric units of one of the possibilities are in agreement with the results of X-ray structure analyses. First the previously proposed planar tetrametalate ion [M4O12(OH)4]4--is formed by stepwise aggregation according to an addition mechanism. This species undergoes a rearrangement of the coordination sphere of two of the M atoms and is then subject to a polycondensation resulting in a polytetrametalate chain, [M4O144-]n.

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Understanding of the fast mediated bioelectrocatalytic reaction on microelectrodes based on an analytical formula

Journal of Electroanalytical Chemistry ◽

10.1016/j.jelechem.2021.115211 ◽

2021 ◽

Vol 888 ◽

pp. 115211

Author(s):

Yu Sugimoto

Keyword(s):

Analytical Formula

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An Improved Machine Learning-Based Employees Attrition Prediction Framework with Emphasis on Feature Selection

Mathematics ◽

10.3390/math9111226 ◽

2021 ◽

Vol 9 (11) ◽

pp. 1226

Author(s):

Saeed Najafi-Zangeneh ◽

Naser Shams-Gharneh ◽

Ali Arjomandi-Nezhad ◽

Sarfaraz Hashemkhani Zolfani

Keyword(s):

Machine Learning ◽

Feature Selection ◽

Standard Deviation ◽

Analytical Formula ◽

Feature Selection Method ◽

Selection Method ◽

Performance Measure ◽

Learning Approaches ◽

Training Costs ◽

Professional Employees

Companies always seek ways to make their professional employees stay with them to reduce extra recruiting and training costs. Predicting whether a particular employee may leave or not will help the company to make preventive decisions. Unlike physical systems, human resource problems cannot be described by a scientific-analytical formula. Therefore, machine learning approaches are the best tools for this aim. This paper presents a three-stage (pre-processing, processing, post-processing) framework for attrition prediction. An IBM HR dataset is chosen as the case study. Since there are several features in the dataset, the “max-out” feature selection method is proposed for dimension reduction in the pre-processing stage. This method is implemented for the IBM HR dataset. The coefficient of each feature in the logistic regression model shows the importance of the feature in attrition prediction. The results show improvement in the F1-score performance measure due to the “max-out” feature selection method. Finally, the validity of parameters is checked by training the model for multiple bootstrap datasets. Then, the average and standard deviation of parameters are analyzed to check the confidence value of the model’s parameters and their stability. The small standard deviation of parameters indicates that the model is stable and is more likely to generalize well.

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First-arrival traveltime inversion of seismic diving waves observed on undulant surface

Geophysical Journal International ◽

10.1093/gji/ggab025 ◽

2021 ◽

Vol 225 (2) ◽

pp. 1020-1031

Author(s):

Huachen Yang ◽

Jianzhong Zhang ◽

Kai Ren ◽

Changbo Wang

Keyword(s):

Turning Points ◽

Analytical Formula ◽

Velocity Model ◽

Western China ◽

Inversion Method ◽

Mountain Area ◽

Traveltime Inversion ◽

Static Correction ◽

Velocity Models ◽

First Arrival

SUMMARY A non-iterative first-arrival traveltime inversion method (NFTI) is proposed for building smooth velocity models using seismic diving waves observed on irregular surface. The new ray and traveltime equations of diving waves propagating in smooth media with undulant observation surface are deduced. According to the proposed ray and traveltime equations, an analytical formula for determining the location of the diving-wave turning points is then derived. Taking the influence of rough topography on first-arrival traveltimes into account, the new equations for calculating the velocities at turning points are established. Based on these equations, a method is proposed to construct subsurface velocity models from the observation surface downward to the bottom using the first-arrival traveltimes in common offset gathers. Tests on smooth velocity models with rugged topography verify the validity of the established equations, and the superiority of the proposed NFTI. The limitation of the proposed method is shown by an abruptly-varying velocity model example. Finally, the NFTI is applied to solve the static correction problem of the field seismic data acquired in a mountain area in the western China. The results confirm the effectivity of the proposed NFTI.

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A Study of UVER in Santiago, Chile Based on Long-Term In Situ Measurements (Five Years) and Empirical Modelling

Energies ◽

10.3390/en14020368 ◽

2021 ◽

Vol 14 (2) ◽

pp. 368

Author(s):

Lisdelys González-Rodríguez ◽

Amauri Pereira de Oliveira ◽

Lien Rodríguez-López ◽

Jorge Rosas ◽

David Contreras ◽

...

Keyword(s):

Urban Areas ◽

Solar Spectrum ◽

Sun Exposure ◽

Great Accuracy ◽

In Situ Measurements ◽

Uv Index ◽

Empirical Modelling ◽

The People

Ultraviolet radiation is a highly energetic component of the solar spectrum that needs to be monitored because is harmful to life on Earth, especially in areas where the ozone layer has been depleted, like Chile. This work is the first to address the long-term (five-year) behaviour of ultraviolet erythemal radiation (UVER) in Santiago, Chile (33.5° S, 70.7° W, 500 m) using in situ measurements and empirical modelling. Observations indicate that to alert the people on the risks of UVER overexposure, it is necessary to use, in addition to the currently available UV index (UVI), three more erythema indices: standard erythemal doses (SEDs), minimum erythemal doses (MEDs), and sun exposure time (tery). The combination of UVI, SEDs, MEDs, and tery shows that in Santiago, individuals with skin types III and IV are exposed to harmfully high UVER doses for 46% of the time that UVI indicates is safe. Empirical models predicted hourly and daily values UVER in Santiago with great accuracy and can be applied to other Chilean urban areas with similar climate. This research inspires future advances in reconstructing large datasets to analyse the UVER in Central Chile, its trends, and its changes.

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“I’ve Heard of It, Yes, but I Can’t Remember What Exactly It Was”—A Qualitative Study on Awareness, Knowledge, and Use of the UV Index

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18041615 ◽

2021 ◽

Vol 18 (4) ◽

pp. 1615

Author(s):

Katharina Diehl ◽

Tatiana Görig ◽

Charlotte Jansen ◽

Maike Carola Hruby ◽

Annette B. Pfahlberg ◽

...

Keyword(s):

Qualitative Study ◽

Qualitative Content Analysis ◽

Sun Protection ◽

Structured Interviews ◽

Protection Factor ◽

Protection Measures ◽

Uv Index ◽

Correct Definition ◽

Definition Of

Pharmacists and pharmaceutical technicians play an important role in counselling customers regarding sunscreen use and sun protection measures. A potentially helpful tool that can be used during counselling is the ultraviolet index (UVI), which informs individuals when and what sun protection measures are needed at a specific place and time. Our aim in this qualitative study was to explore awareness, knowledge, and use of the UVI during counselling in pharmacies. We used semi-structured interviews with pharmacists and pharmaceutical technicians (n = 20) to answer our research questions. Interviews were audiotaped, transcribed verbatim, and analyzed using qualitative content analysis. During the interviews pharmacists and pharmaceutical technicians revealed a lot of uncertainty and lack of knowledge regarding the UVI. Eight professionals were able to give a correct definition of UVI. Amongst others, the UVI was confused with sun protection factor. Overall, the UVI was hardly used during the counselling of customers. The UVI was developed to provide guidance when which type of sun protection is required to avoid detrimental effects of ultraviolet radiation. For effective implementation, both the general population and health professionals (e.g., pharmacists) have to increase their knowledge about the UVI. This would strengthen its use during professional counselling in pharmacies and may help to reduce the incidence of skin cancer over the long term.

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Local modal participation analysis of nonlinear systems using Poincaré linearization

Nonlinear Dynamics ◽

10.1007/s11071-019-05363-1 ◽

2019 ◽

Vol 99 (1) ◽

pp. 803-811 ◽

Cited By ~ 2

Author(s):

Boumediene Hamzi ◽

Eyad H. Abed

Keyword(s):

Nonlinear Systems ◽

Autonomous Systems ◽

Analytical Formula ◽

Linear Case ◽

Local Mode ◽

Initial Condition ◽

Initial State ◽

State Participation ◽

Symmetry Assumption ◽

Definition Of

AbstractThe paper studies an extension to nonlinear systems of a recently proposed approach to the definition of modal participation factors. A definition is given for local mode-in-state participation factors for smooth nonlinear autonomous systems. While the definition is general, the resulting measures depend on the assumed uncertainty law governing the system initial condition, as in the linear case. The work follows Hashlamoun et al. (IEEE Trans Autom Control 54(7):1439–1449 2009) in taking a mathematical expectation (or set-theoretic average) of a modal contribution measure over an uncertain set of system initial state. Poincaré linearization is used to replace the nonlinear system with a locally equivalent linear system. It is found that under a symmetry assumption on the distribution of the initial state, the tractable calculation and analytical formula for mode-in-state participation factors found for the linear case persists to the nonlinear setting. This paper is dedicated to the memory of Professor Ali H. Nayfeh.

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