Degradation modelling of railway infrastructure

2021 ◽  
Author(s):  
Ewa Laskowska ◽  
Jørn Vatn
Keyword(s):  
Wiener Process ◽  
Empirical Data ◽  
Bayesian Framework ◽  
Degradation Model ◽  
Explanatory Variables ◽  
Linear Drift ◽  
Railway Infrastructure ◽  
The Impact ◽  
Railway Substructure

<p>In this paper the Wiener process with linear drift is proposed as a degradation model for the railway substructure. The model is based on the empirical data describing loss of tracks quality over the distance of one kilometre. The impact of explanatory variables on tracks degradation is investigated. The Bayesian framework is applied to examine uncertainty in the development of degradation for different sections along the tracks.</p>

scholarly journals The Innovation of Government Bonds in the Growth of an Emergent Capital Market

2021 ◽  
Vol 7 (1) ◽  
pp. 103
Author(s):  
Cordelia Onyinyechi Omodero ◽  
Philip Olasupo Alege
Keyword(s):  
Capital Market ◽  
Research Work ◽  
Government Bonds ◽  
Market Capitalization ◽  
Market Growth ◽  
Explanatory Variables ◽  
The Government ◽  
The Impact ◽  
Total Market ◽  
The Capital Market

The growth of an emerging capital market is necessary and requires all available resources and inputs from various sources to realize this objective. Several debates on government bonds’ contribution to Nigeria’s capital market developmental growth have ensued but have not triggered comprehensive studies in this area. The present research work seeks to close the breach by probing the impact of government bonds on developing the capital market in Nigeria from 2003–2019. We employ total market capitalization as the response variable to proxy the capital market, while various government bonds serve as the independent variables. The inflation rate moderates the predictor components. The research uses multiple regression technique to assess the explanatory variables’ impact on the total market capitalization. At the same time, diagnostic tests help guarantee the normality of the regression model’s data distribution and appropriateness. The findings reveal that the Federal Government of Nigeria’s (FGN) bond is statistically significant and positive in influencing Nigeria’s capital market growth. The other predictor variables are not found significant in this study. The study suggests that the Government should improve on the government bonds’ coupon, while still upholding the none default norm in paying interest and refunding principal to investors when due.

scholarly journals To Swab or Not to Swab? The Lesson Learned in Italy in the Early Stage of the COVID-19 Pandemic

2021 ◽  
Vol 11 (9) ◽  
pp. 4042
Author(s):  
Paola Berchialla ◽  
Maria Teresa Giraudo ◽  
Carmen Fava ◽  
Andrea Ricotti ◽  
Giuseppe Saglio ◽  
...  
Keyword(s):  
Early Phase ◽  
Early Stage ◽  
Respiratory Illness ◽  
Explanatory Variables ◽  
Daily Number ◽  
Testing Strategies ◽  
Serious Infections ◽  
The Impact ◽  
Epidemiological Link ◽  
Severe Respiratory Illness

Testing for the SARS-CoV-2 infection is critical for tracking the spread of the virus and controlling the transmission dynamics. In the early phase of the pandemic in Italy, the decentralized healthcare system allowed regions to adopt different testing strategies. The objective of this paper is to assess the impact of the extensive testing of symptomatic individuals and their contacts on the number of hospitalizations against a more stringent testing strategy limited to suspected cases with severe respiratory illness and an epidemiological link to a COVID-19 case. A Poisson regression modelling approach was adopted. In the first model developed, the cumulative daily number of positive cases and a temporal trend were considered as explanatory variables. In the second, the cumulative daily number of swabs was further added. The explanatory variable, given by the number of swabs over time, explained most of the observed differences in the number of hospitalizations between the two strategies. The percentage of the expected error dropped from 70% of the first, simpler model to 15%. Increasing testing to detect and isolate infected individuals in the early phase of an outbreak improves the capability to reduce the spread of serious infections, lessening the burden of hospitals.

scholarly journals How far from the road should land cover be assessed? A case study on mesopredator mortality on roads

2021 ◽  
Vol 67 (2) ◽  
Author(s):  
Angelika Nieszała ◽  
Daniel Klich
Keyword(s):  
Land Cover ◽  
Red Fox ◽  
Home Range Size ◽  
Buffer Size ◽  
Local Conditions ◽  
Explanatory Variables ◽  
The Road ◽  
Spatially Correlated ◽  
European Badger ◽  
The Impact

AbstractThe methods used to assess the significance of land cover in the vicinity of a road for the mortality of mesopredators are diverse. In assessing the effect of land cover along the road on road causalities, scientists use various buffer sizes, or even no buffer along the road. The aim of this study was to verify how results of land cover effects on the mortality of mesopredators on roads may differ when analyzing various buffer sizes from the road. We assessed road causalities in the Warmian-Masurian voivodeship (Poland) from 3 consecutive years: 2015, 2016, and 2017. The roads were divided into equal sections of 2000 m each with buffer size of radius: 10, 250, 500, and 1000 m. We analyzed the number of road kills of red fox and European badger separately in a generalized linear model, whereas explanatory variables we used land cover types (based on the Corine Land Cover inventory) and traffic volume. Mean annual mortality from road collisions amounts to 2.36% of the red fox population and 3.82% of the European badger population. We found that the buffer size determines the results of the impact of land cover on mesocarnivore mortality on roads. The red fox differed from the European badger in response to land cover depending on the buffer size. The differences we have shown relate in particular to built-up areas. Our results indicate a 500-m buffer as best reflecting the land cover effects in road kills of both species. This was confirmed by model evaluation and a tendency to use or avoid the vicinity of human settlements of the analyzed species. We concluded that buffer size will probably affect mostly the significance of cover types that are spatially correlated with roads, positively or negatively. We suggest that the home range size of given species in local conditions should be assessed before determining the size of the buffer for analysis.

scholarly journals Does Mobile Phone Penetration Affect Divorce Rate? Evidence from China

2018 ◽  
Vol 10 (10) ◽  
pp. 3701 ◽  
Author(s):  
Jiaping Zhang ◽  
Mingwang Cheng ◽  
Xinyu Wei ◽  
Xiaomei Gong
Keyword(s):  
Mobile Phone ◽  
Eastern China ◽  
Divorce Rate ◽  
Central China ◽  
Western China ◽  
Explanatory Variables ◽  
Information And Communication ◽  
Lag Times ◽  
One Year ◽  
The Impact

Marital happiness is an important symbol of social harmony and can help promote sustainable economic and social development. In recent years, the rapid rise of the divorce rate in China, a country where the divorce rate had previously been low, has attracted wide attention. However, few articles have focused on the popularization of information and communication technology's impact on China’s rising divorce rate in recent years. As a first attempt, the provincial panel data during the period 2001–2016 is applied to study quantitatively the relationship between mobile phone penetration and the divorce rate. In order to get more reliable estimation results, this paper uses two indicators to measure the divorce rate, and quantile regression is applied for further analysis. Additionally, one-year to five-year lag times of the mobile phone penetration are used as the core explanatory variables in order to analyse the lagging effect of mobile phone penetration on divorce rate. The result shows that the correlation between the mobile phone penetration and the divorce rate was statistically positive significant in China during the period 2001–2016. Furthermore, the paper also finds that mobile phone penetration had the greatest impact on divorce rate in central China, followed by eastern China, but it was not obvious in western China during this period. From a technological perspective, this paper provides some possible explanations for the rising divorce rate in China in recent years, and further enriches the relevant research on the impact of the development of information and communication technology on societal changes.

Reliability-based covariate analysis for complex systems in heterogeneous environment: Case study of mining equipment

2018 ◽  
Vol 233 (4) ◽  
pp. 593-604
Author(s):  
Amin Moniri-Morad ◽  
Mohammad Pourgol-Mohammad ◽  
Hamid Aghababaei ◽  
Javad Sattarvand
Keyword(s):  
Complex Systems ◽  
Cox Regression ◽  
Reliability Evaluation ◽  
Distribution Functions ◽  
Heterogeneous Environment ◽  
Mining Equipment ◽  
Data Set ◽  
Explanatory Variables ◽  
The Impact

Operational heterogeneity and harsh environment lead to major variations in production system performance and safety. Traditional probabilistic model is dealt with time-to-event data analysis, which does not have the capability of quantifying and simulation of these types of complexities. This research proposes an integrated methodology for analyzing the impact of dominant explanatory variables on the complex system reliability. A flexible parametric proportional hazards model is developed by focusing on standard parametric Cox regression model for reliability evaluation in complex systems. To achieve this, natural cubic splines are utilized to create a smooth and flexible baseline hazards function where the standard parametric distribution functions do not fit into the failure data set. A real case study is considered to evaluate the reliability for multi-component mechanical systems such as mining equipment. Different operational and environmental explanatory variables are chosen for the analysis process. Research findings revealed that precise estimation of the baseline hazards function is a major part of the reliability evaluation in heterogeneous environment. It is concluded that an appropriate maintenance strategy potentially mitigate the equipment failure intensity.

scholarly journals INFLUENCE OF STATE GRANTS UPON EFFECTIVENESS OF THE ENTERPRISES IN THE AGRICULTURAL SECTOR

2020 ◽  
Vol 18 (Suppl.1) ◽  
pp. 607-613
Author(s):  
D. Stoyanova ◽  
D. Stoyancheva
Keyword(s):  
Empirical Data ◽  
Agricultural Sector ◽  
Positive Influence ◽  
Innovation Activity ◽  
Investment Activity ◽  
Agricultural Enterprises ◽  
State Grants ◽  
The Impact ◽  
Positive Effect

This report aims to analyze the impact of state grants upon the effectiveness efficiency of the enterprises in the Agricultural sector. The presence/absence of the correlation between the “received state grants - financial results from the activity of the agricultural enterprises” was studied. The efficiency of agricultural enterprises is expressed through the indicators of profitability and productivity. The empirical data for a period of 10 years 2008 – 2017 were shown in the study. The main activities of the surveyed enterprises are crop, livestock and combined - crop-livestock. Based on the results obtained, it is expected that the receipt of grants will have a positive influence on the performance of enterprises in the agricultural sector, measured by indicators of effectiveness and productivity. The following research hypotheses have been proved: the positive effect of the grant is more obvious in larger agricultural enterprises, which have higher productivity and profitability compared to small and medium-sized farms; agricultural enterprises which receive grants and are characterized by higher investment activity and are also characterized by higher innovation activity; based on the predominant number of crop enterprises, it is assumed that this type of activity leads to the achievement of higher financial results as a result of the activity of the agricultural enterprises; the age of the enterprises, expressed through the years of their activity, contributes significantly to higher profitability and productivity of the carried out activity.

scholarly journals Impact of Liquidity on Rural and Community Banks Profitability in The Eastern Region of Ghana

2021 ◽  
Vol 1 (3) ◽  
pp. 129-148
Author(s):  
Osumanu Alhassan ◽  
Oscar Opoku Agyemang Opoku
Keyword(s):  
Secondary Data ◽  
Easy Access ◽  
Eastern Region ◽  
Community Banks ◽  
Loan Portfolio ◽  
Explanatory Variables ◽  
Financial Climate ◽  
Information And Communication ◽  
The Impact

Despite the major role played by rural and community banks in economic development and in the financial climate, their performance over a decade now have not been up to expectations. They continue to experience huge challenges due to innovations in technology as well as globalization which create opportunities for growth. The study was to examine the impact of liquidity on rural and community banks in the Eastern Region of Ghana selected from eleven (11) banks for the period of ten years from 2007 – 2016. The study used panel data and secondary data to collate the ratios from all the selected rural and community banks. A regression model was developed with Return on Asset as the dependent variable accompanied with other six explanatory variables. It was revealed that quality of loan portfolio ratio; capital ratio and loan to total assets had significant and positive relationship with profitability. It was also revealed that shocks in all the liquidity variables had one or other implications on profitability. Finally, based on finding seven, which states that cost to income has negative and significant effect on profitability, the study recommended that management must adopt information and communication technology to reduce cost and easy access to banks’ product in the form of Automated Teller Machine.  

scholarly journals The Suitability of the Satellite Metrological Inputs Source on the Hydrological Model in a Small Urban Catchment

2016 ◽  
Author(s):  
Song Song ◽  
Youpeng Xu ◽  
Jiali Wang ◽  
Jinkang Du ◽  
Jianxin Zhang ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Potential Evapotranspiration ◽  
Model Performance ◽  
Yangtze River Delta ◽  
Precipitation Data ◽  
Model Quality ◽  
Small Catchment ◽  
Explanatory Variables ◽  
Distributed Models ◽  
The Impact

Distributed/semi-distributed models are considered to be sensitive to the spatial resolution of the data input. In this paper, we take a small catchment in high urbanized Yangtze River Delta, Qinhuai catchment as study area, to analyze the impact of spatial resolution of precipitation and the potential evapotranspiration (PET) on the long-term runoff and flood runoff process. The data source includes the TRMM precipitation data, FEWS download PET data, and the interpolated metrological station data. GIS/RS technique was used to collect and pre-process the geographical, precipitation and PET series, which were then served as the input of CREST (Coupled Routing and Excess Storage) model to simulate the runoff process. The results clearly showed that, the CREST model is applicable to the Qinhuai catchment; the spatial resolution of precipitation had strong influence on the modelled runoff results and the metrological precipitation data cannot be substituted by the TRMM data in small catchment; the CREST model was not sensitive to the spatial resolution of the PET data, while the estimation fourmula of the PET data was correlated with the model quality. This paper focused on the small urbanized catchment, suggesting the influential explanatory variables for the model performance, and providing reliable reference for the study in similar area.

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