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Abstract

It is shown how a stability test, alternative to the classical Routh test, can profitably be applied to check the presence of polynomial roots inside half-planes or even sectors of the complex plane. This result is obtained by exploiting the peculiar symmetries of the root locus in which the basic recursion of the test can be embedded. As is expected, the suggested approach proves useful for testing the stability of fractional-order systems. A pair of examples show how the method operates. It is believed that the suggested geometric approach can also be of some didactic value in introducing basic control-system tools to engineering students.
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Authors and Affiliations

Daniele Casagrande
1
Wiesław Krajewski
2
Umberto Viaro
1

  1. Polytechnic Department of Engineering and Architecture, University of Udine, via delle Scienze 206, 33100 Udine, Italy
  2. Systems Research Institute, Polish Academy of Sciences, ul. Newelska 6, 01–447 Warsaw, Poland
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Abstract

New records to lichen flora and bryoflora of Wrangel Island are presented. The additions to the island cryptogam flora include 32 lichens and one lichenicolous fungus, 26 mosses and 11 liverwort species. Acarospora sinopica, Alectoria gowardii, Calogaya bryochrysion, Caloplaca cf. sibirica, Hymenelia ceracea, Porpidia ochrolemma, and Sagiolechia protuberans are new not only to the island but to the Russian Far East. Two lichen species ( Lecidea lithophila and Rinodina terrestris), as well as two liverwort taxa ( Clevea hyalina Lophoziopsis excisa var. elegans and Pseudolophozia debiliformis), are new to the Chukotka Autonomous Area. Two of the reported moss species ( Funaria arctica and Schistidium umbrosum) are extremely rare. Location data and ecological descriptions for the newly reported species are included.
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Authors and Affiliations

Gregory Evdokimov
1
Olga Afonina
2
Liudmila Konoreva
2 3 4
Roman Obabko
5
Yuriy Mamontov
4 6
Sergey Chesnokov
2 3
Ivan V. Frolov
7
Ulyana V. Babiy
8

  1. St. Petersburg State University, Universitetskaya emb. 7–9, 199034 St. Petersburg, Russia
  2. Komarov Botanical Institute of the Russian Academy of Sciences, Professor Popov St. 2, 197376 St. Petersburg, Russia
  3. Botanical Garden-Institute Far Eastern Branch of the Russian Academy of Sciences, Makovskogo Str., 142, 690024, Vladivostok, Russia
  4. Avrorin Polar-Alpine Botanical Garden-Institute of Kola Scientific Centre of the Russian Academy of Sciences, 184250 Kirovsk, Murmansk Region, Russia
  5. Federal Research Center Karelian Scientific Center of the Russian Academy of Sciences, Petrozavodsk, Russia
  6. Tsitsin Main Botanical Garden of the Russian Academy of Sciences, 127276, Moscow, Russia
  7. Institute Botanic Garden Ural Branch of Russian Academy of Sciences, Vosmogo Marta Str. 202a, 620144, Yekaterinburg, Russia
  8. Wrangel Island State Reserve, Kuvaeva St., 23, 689400, Pevek, Chukotka Autonomous District, Russia
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Abstract

Member states of the European Union face a growing number of irregular migrants attempting to cross the Unions maritime border in the Mediterranean. An illegal transfer route there allows tens of thousands to enter the EU, mostly from Africa and Asia. The southern EU states of Italy, Malta, Greece and Spain cope with the problem with increasing difficulty. Their border enforcement authorities are to be aided by EUs specialized Rapid Border Intervention Teams (RABITs). The task of coordinating the measures lies ahead of the European Agency for the Management of Operational Cooperation at the External Borders of the Member States of the European Union (Frontex), based in Warsaw. Frontex began its operations in October 2005. The European Parliament took position on the issue irregular migration in the Mediterranean and called upon the Commission and the Council to strengthen the efforts against human trafficking and smuggling. The problem has also been addressed by European Economic and Social Committee and Committee of the Regions.

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Authors and Affiliations

Dorota Pyć
ORCID: ORCID

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