Faculty of Mechanical Engineering, Technical University of Kosice, 042 00 Kosice, Slovakia.
Faculty of Electrical Engineering and Informatics, Technical University of Kosice, 042 00 Kosice, Slovakia.
Int J Environ Res Public Health. 2020 May 26;17(11):3759. doi: 10.3390/ijerph17113759.
The transport sector, including air transport, represents an important source of air pollution. The present article deals with the current situation regarding greenhouse gas emissions in the air in 27 European Union (EU-27) member states. Every member state is characterized by selected parameters that determine the unique nature of a particular country (e.g., population, area, life expectancy, gross domestic product (GDP) per capita, etc.). In addition to these parameters, there were also other parameters which were monitored as they characterize the amount of greenhouse gas emissions and the impact of aviation on these emissions. The main purpose of the article is to compare the European Union member states on the basis of 15 examined parameters. The identification of similarities between the EU-27 member states with regard to the selected parameters was carried out by applying principal component analysis (PCA) and hierarchical cluster analysis. The average linkage method was applied to create a dendrogram representing the similarities between the examined member states. The value of the cophenetic correlation coefficient CC = 0.923 confirmed the correct application of the average linkage method. The cluster analysis outputs were five similarity-based homogeneous groups (clusters) into which the 27 member states were divided on the basis of the examined variables.
交通运输部门（包括航空运输）是空气污染的一个重要来源。本文介绍了 27 个欧盟成员国（EU-27）空气中温室气体排放的现状。每个成员国都有一些特定的参数，这些参数决定了一个国家的独特性质（例如，人口、面积、预期寿命、人均国内生产总值（GDP）等）。除了这些参数外，还有其他一些参数也被监测，因为它们可以描述温室气体排放量和航空对这些排放量的影响。本文的主要目的是基于 15 个被考察的参数来比较欧盟成员国。通过应用主成分分析（PCA）和层次聚类分析，确定了欧盟 27 个成员国在所选参数上的相似性。采用平均链接法创建了一个代表被考察成员国之间相似性的聚类树图。Cophenetic 相关系数 CC 的值为 0.923，证明了平均链接法的正确应用。聚类分析的结果是将 27 个成员国分为五个基于相似性的同质组（聚类），这是基于被考察的变量进行的分组。
