Diagnostics of the drive shaft bearing based on vibrations in the high-frequency range as a part of the vehicle's self-diagnostic system

Currently, one of the trends in the automotive industry is to make vehicles as autonomous as possible. In particular, this concerns the implementation of complex and innovative selfdiagnostic systems for cars. This paper proposes a new diagnostic algorithm that evaluates the performance of the drive shaft bearings of a road vehicle during use. The diagnostic parameter was selected based on vibration measurements and machine learning analysis results. The analyses included the use of more than a dozen time domain features of vibration signal in different frequency ranges. Upper limit values and down limit values of the diagnostic parameter were determined, based on which the vehicle user will receive information about impending wear and total bearing damage. Additionally, statistical verification of the developed model and validation of the results were performed.

RELATIONSHIP MARKETING IN CUSTOMER LOYALTY OF COMMERCIAL GALLERIES IN TIMES OF COVID-19

The main objective of the study is to determine the level of dependence between relationship marketing and the level of customer loyalty to the brand. The study was conducted through a quantitative approach using the CAWI method. Relationships were determined by several factors. The loyalty factors are: Differentiation, Personalization, Satisfaction, Loyalty, usually. The relationship marketing indicators are: Trust, Commitment, Customer Satisfaction, Intention to renew the relationship. The survey results were processed using statistical methods. In particular, internal consistency checks performed on the questionnaire with questions to use Cronbach’s alpha. The use of such criteria allows to draw conclusions about the high level of consistency. The coefficient of determination was used for statistical verification of dependence. The results of the calculations confirmed a high level of dependence. Dependence was also confirmed by calculating p-values with a high level of probability. Conclusions were drawn according to the results of the empirical investigation.

Providing statistical stability of qualimetric studies on the basis of geochronological tracking

Geochronological tracking has received wide recognition as an appropriate scientific and methodological tool and an effective information technology of qualimetric research in the interests of ensuring high quality of transport services, transportation efficiency, analysis of the facts of insufficient meeting the needs of the population with spatially remote services, etc. On the basis of geochronotracking, a procedure has been developed for statistical verification of research hypotheses about stable trends in changes in the quality of various spatio-temporal processes. The reliability and validity of accepting a particular hypothesis in the framework of a qualimetric research is determined by the representativeness of the volume of initial data on geographical movements, considered as a selection from the general population. This article is devoted to the analysis of this dependence and the development of an algorithm for assessing the specified stability (significance).

Four-dimensional variational (4DVAR) performance test with assimilation satellite and radar data (case study of a heavy rainfall Bengkulu March 4, 2019)

Four-dimensional variational (4DVAR) is one of the assimilation techniques considering time integration to distribute observational data at time window intervals. In this study, we aim to evaluate the 4DVAR assimilation technique using satellite and radar data to simulate a heavy rainfall case in Bengkulu on March 4, 2019. The result shows that radar data assimilation (DA-RAD) can improve rainfall pattern over Bengkulu mainland areas, while the satellite data assimilation (DA-SAT) enhances rainfall over the ocean. In addition, for temporal analysis, the DA-RAD successfully correct the initial time of the event, producing the smallest error and the best correlation in statistical verification, also a small bias and higher accuracy for discrete verification. However, DA-SAT is more capable to improve rainfall accumulation with the lowest FAR value. In conclusion, compared to others, both satellite and radar can be used as assimilation data for 4DVAR methods as they have different roles in increasing the quality of model performance.

Validation of the modified Témez rational model in the watersheds of Norte de Santander, Colombia

Physics includes the study and investigation of the phases that make up the hydrological cycle, including the estimation of flow rates in river basins, most of which are not instrumented, i.e., they lack historical records of circulating flows. For this situation, the application of hydrological models can allow flow estimates to be made. In the Department of Norte de Santander, Colombia, some watersheds do not have instrumentation for flow measurement or hydrological modeling methodologies appropriate to the site. Therefore, methods such as the modified rational model of Teméz are used, even without knowing the relevance of its applicability to the site conditions. Consequently, for the present research, the Teméz model was validated in watersheds of the Norte de Santander Department to estimate the values of extreme flows with a return period of 100 years. In this sense, 11 watersheds were selected, which contained historical rainfall data greater than 20 years and a drainage network of fewer than 1000 Km2. It was found that the Teméz model overestimates the real flows of the 11 hydrological basins, where the climatological parameters used in the application of the Fhrüling factor and its statistical verification using multivariate regression did not achieve an acceptable correlation.

Simulation of atmospheric radiocesium (137Cs) from Fukushima nuclear accident using FLEXPART-WRF driven by ERA5 reanalysis data

This study investigates short-range atmospheric transport of radiocesium (137Cs) after Fukushima nuclear accident using the Weather Research and Forecasting (WRF) model and the Lagrangian particle dispersion FLEXPART-WRF model. The most up-to-date ERA5 reanalysis dataset is used as initial and boundary condition for the WRF model for every hour. Four experiments were carried out to examine the sensitivity of simulation results to micro-physics parameterizations in the WRF model with two configured domains of 5 km and 1 km horizontal resolution. Compared with observation at Futaba and Naraha station, all experiments reproduce reasonably the variation of 137Cs concentration from 11/03 to 26/03/2011. Statistical verification as shown in Taylor diagrams highlights noticeable sensitivity of simulation results to different micro-physics choices. Three configurations of the WRF model are also recommended for further study based on their better performance among all.

Risk Factors Affecting Bancassurance Development in Poland

The aim of the article is to identify the risk factors affecting bancassurance development in Poland. The development is understood here as a change of gross written premiums obtained through banks in Poland. The group of risk factors selected in a survey conducted among financial sector employees was subject to statistical verification. The analysis used both variables directly related to the insurance product (e.g., a regulatory restriction of insurance acquisition costs) as well as those resulting from the specificity of the bancassurance channel, such as the sales of banking products, i.e., cash loans, housing loans and the value of funds placed by customers on deposits. The study was conducted on the basis of data on the gross premiums written in Poland in the years 2004–2019. The result of the applied model confirms the assumptions and the importance of insurance distribution in banks. Significant risk factors (statistically significant) which determine gross premiums written in the bancassurance channel are: the size of policyholder’s family (number of children, dependants) represented by the average number of people in a household in Poland, demand on mortgage loans represents by bank housing loans for households and agent’s commission, represented by the ratio of acquisition costs to gross written premium. The results of the econometric model obtained are consistent with expectations arising from the principles and practice of cooperation between banks and insurers as well as the specificity of insurance products distribution (also local) in the bancassurance channel.

Pengaruh pembelajaran manajemen keuangan terhadap perilaku berinvestasi yang dimoderasi gender

<span>The purpose of this study was to analyze the effect of learning financial management on investment behavior of Master of Management students at Pamulang University and to determine the effect of learning financial management on investment behavior moderated by gender. This research is an applied research type with a descriptive statistical verification approach. The population is Master of Management students class 2018 and 2019, sampling using purposive sampling so that the number of samples is 100 respondents. Data analysis using path analysis method using SmartPLS program. Data processing techniques using SEM method based on Partial Least Square (PLS). The results showed that there was an effect of financial management learning on investment behavior of Pamulang University Master of Management students, gender variable could not moderate the effect of financial management learning on investment behavior of Pamulang University Master of Management students.</span>

THE USE OF INTERNET TECHNOLOGIES IN MEDICAL EDUCATIONAL SCHOOLS

The article emphasizes the need for the application of innovative Internet technologies in medical schools. The authors submit some practical aspects of using educational blog Blogger, mental maps Mindomo and application Learning Apps in training of medical students when they study the professional disciplines. The results of a survey of would-be doctors and junior medical staff are described. They prove the effectiveness of the use of blogs, mental maps and online exercises by means of Learning Apps in studying of professional disciplines. The purpose of the article is to highlight the methodology and results of experimental work aimed at the verification of the effectiveness of using of innovative Internet technologies in medical schools. The experimental verification of the effectiveness of the introduction innovative Internet technologies on the training of future junior medical staff in study of special disciplines is presented. It was specified that future doctors and junior medical staff of the experimental groups at the formative stage of the experiment received better results, than the students of the control groups and they have a higher level of readiness for professional activity. The statistical verification also confirmed the effectiveness of the implementation of Internet technologies.

A Paradox of the Average Waiting Time for the Case of a Single Bottleneck on the Commuters’ Route

Average waiting time is considered as one of the basic performance indicators for a bottleneck zone on a route for commuter traffic. It turns out that the average waiting time in a queue remains paradoxically unchanged regardless of how fast the queue dissolves for a single bottleneck problem. In this study, the paradox is verified theoretically for the deterministic case with constant arrival and departure rates. Consistent results with the deterministic case have also been obtained by simulation runs for which vehicle interarrival time is a random variable. Results are tabulated for interarrival times which have uniform, triangular, normal, and exponential distributions along with a statistical verification of the average waiting time paradox.