Search results

Filters

  • Journals
  • Authors
  • Keywords
  • Date
  • Type

Search results

Number of results: 6
items per page: 25 50 75
Sort by:
Download PDF Download RIS Download Bibtex

Abstract

The article presents a synthetic analysis of the crude oil market in Poland. As of today, this safety is provided mainly on the basis of native lignite and hard coal resources. However, the analysis of the hard coal market conducted by the authors indicates that the carried out mining restructuring (among others) led to an excessive reduction of mining volume and employment level in the hard coal mining sector. This led to a precedent situation when Poland became an importer of this energy carrier. In addition, the European Union’s requirements for greenhouse gas emissions must be taken into account. In connection with the above, it is necessary to search for new energy sources or technologies that enable hard coal to meet the requirements. It is possible to apply the so-called clean coal technologies that allow the greenhouse gas emissions generated during coal combustion to be reduced. As of today, they are not used on a mass scale, because the use of this type of technology involves additional financial expenses. However, taking into account that technologies have been growing faster and faster, are modernized in a shorter time, making a breakthrough discovery took hundreds of years, now it is often a few months, clean coal technologies can become the optimal solution in the near future. It is also necessary to diversify the sources of obtaining imported energy carriers.

The article describes coal and crude oil in terms of their mutual substitution. The article is a continuation of research conducted by the authors. Previous publications presented considerations on analogous topics related to natural gas and renewable energy sources. The crude oil market in Poland was analyzed and forecasts for oil extraction and the demand in the world and Poland by 2023 were presented. The SARIMA model was also created. The model made it possible to obtain oil an prices forecast.

Go to article

Authors and Affiliations

Aurelia Rybak
ORCID: ORCID
Anna Manowska
Download PDF Download RIS Download Bibtex

Abstract

The results of statistic estimation of measurements done within surface waters monitoring programme were described. The biogens concentrations (the years 1994-1998) and the oxygen indicators (the years 1992-1996) in the measurement point on Odra river in Krajnik Dolny constituted the date base. The time changeability of these indicators was well described by Jog-normal and gamma distributions was shown. The normalised distributions were also given.The autocorrelation and the periodicity were examined. It was stated that the considered time sequences were characterised by the strong autocorrelation and the periodicity. Using the ARIMA process the modelling of measurement series was realised. After the selection of models, the programming of examined indicators changes was accomplished. It was shown that using ARIMA models valuable results can be obtained.
Go to article

Authors and Affiliations

Jerzy Straszko
Marzena Jastrzębska
Download PDF Download RIS Download Bibtex

Abstract

This paper summarizes the arguments and counterarguments within the scientific discussion

on developing the free-carbon economy in Ukraine. The main purpose of the paper is elaborating

the energy efficiency profile of Ukraine to assure the development of the free-carbon economy. To

achieve this purpose, the authors carried out an investigation in the following logical sequence.

Firstly, the bibliometric analysis of 4674 of the most cited articles indexed by the Scopus database

was conducted. The obtained findings indicated that the green economy transformation depended

on the main factors such as economic performance, corruption, macroeconomic stability, social

welfare, shadow economy etc. As a result, the forecast of the final energy consumption to 2030

was performed. The methodological tool of this research is based on the Autoregressive Integrated

Moving Average (ARIMA) model. This study involved data of the Visegrad countries (Poland, the

Czech Republic, the Slovak Republic and Hungary) and Ukraine from 2000 to 2018. The base of

data is Eurostat, the EU statistical service. Based on the obtained results of analyzing the green

economic transformation in the Visegrad countries and Ukraine, the authors intimated the existence

of the significant energy-efficient gap in Ukraine compared to the analyzed countries. In reliance on

the experience of the Visegrad countries and the forecast results, the authors provided the main recommendations

for providing the green transforming in Ukraine. The authors highlighted that the obtained

results of this paper were considered to be the base for future investigations considering the influence

of endogenous and exogenous factors on developing the free-carbon economy in Ukraine.

Go to article

Authors and Affiliations

Yana Us
ORCID: ORCID
Tetyana Pimonenko
ORCID: ORCID
Oleksii Lyulyov
ORCID: ORCID
Download PDF Download RIS Download Bibtex

Abstract

The article presents the possibility of using the Cobb-Douglas production function for planning in a turbulent environment. A case study was carried out – the Cobb-Douglas function was used to examine the condition of the Polish hard coal mining industry and the progress which has been made after undertaking certain activities aimed at increasing the competitiveness of coal companies over recent years. Only the correct and confirmed identification of the causes of irregularities in the production process can allow for the introduction of effective remedies. The effectiveness of the solutions proposed by the author has been confirmed thanks to the simulation during which the impact of the proposed production strategy on the parameters of the CD function was examined. Three variants of production functions models were created and production productivity rates and marginal substitution rates were determined. The results enabled the verification of the progress of restructuring as well as identification of the origin of the observed problems and comparison of the current state with the results of analyses carried out in previous years. Scenarios of possible trend developments for the factors introduced into the function model in order to present remedial measures that could improve the process of hard coal extraction were created. The scenarios were created using the ARIMA class models. Which scenario is the most favourable was determined. A computer program, created by the author, for optimising the level and use of labor resources at the level of the entire coal company has been presented.

Go to article

Authors and Affiliations

Aurelia Rybak
ORCID: ORCID
Download PDF Download RIS Download Bibtex

Abstract

Time series models have been used to extract damage features in the measured structural response. In order to better extract the sensitive features in the signal and detect structural damage, this paper proposes a damage identification method that combines empirical mode decomposition (EMD) and Autoregressive Integrated Moving Average (ARIMA) models. EMD decomposes nonlinear and non-stationary signals into different intrinsic mode functions (IMFs) according to frequency. IMF reduces the complexity of the signal and makes it easier to extract damage-sensitive features (DSF). The ARIMA model is used to extract damage sensitive features in IMF signals. The damage sensitive characteristic value of each node is used to analyze the location and damage degree of the damaged structure of the bridge. Considering that there are usually multiple failures in the actual engineering structure, this paper focuses on analysing the location and damage degree of multi-damaged bridge structures. A 6-meter-long multi-destructive steel-whole vibration experiment proved the state of the method. Meanwhile, the other two damage identification methods are compared. The results demonstrate that the DSF can effectively identify the damage location of the structure, and the accuracy rate has increased by 22.98% and 18.4% on average respectively.
Go to article

Authors and Affiliations

Weijia Lu
1
ORCID: ORCID
Jiafan Dong
1
ORCID: ORCID
Yuheng Pan
1
ORCID: ORCID
Guoya Li
1
ORCID: ORCID
Jinpeng Guo
1
ORCID: ORCID

  1. Tianjin Chengjian University, Computer and Information Engineering Department, Tianjin, China

This page uses 'cookies'. Learn more