Vegetation succession in extensive abandoned tall-trunk cherry orchards: a case study on Kaňk Mountain near Kutná Hora (Czech Republic)

Extensive tall-trunk orchards, a component of the central European landscape since the Middle Ages, form a biotope to which a number of plant and animal species are bound that are rare in other habitats. For these reasons, extensive tall-trunk orchards are interesting with regard to nature conservation. Once the management of these low-productivity vegetation sites ceases, the habitat is threatened by successive overgrowth by shrub vegetation. Taking abandoned tall-trunk cherry orchards with dry/mesophilous grassland undergrowth in the locality of Kaňk as an example, the degree of colonization of orchards by woody species and differences in the composition of vegetation cover in different time periods after abandonment were monitored. The results showed that the cover of cherry trees in orchards abandoned before 1990 was approximately 30% lower than that in orchards abandoned after 2000, and the cover of the herb layer was approximately 60% lower. The species diversity of orchards abandoned before 1990 was statistically significantly lower than that of orchards abandoned after 2000. The total cover of all species in habitat in areas of medieval ore extraction was approximately 50% lower than that in land originally used for farming

Alien plants in Central European river ports

River ports represent a special type of urbanized area. They are considered to be an important driver of biological invasion and biotic homogenization on a global scale, but it remains unclear how and to what degree they serve as a pool of alien species. Data for 54 river ports (16 German, 20 Czech, 7 Hungarian, 3 Slovak, and 8 Austrian ports) on two important Central European waterways (the Elbe-Vltava and Danube waterways) were collected over 40 years. In total, 1056 plant species were found. Of these, 433 were alien, representing 41% of the total number of species found in all the studied Elbe, Vltava, and Danube ports. During comparison of floristic data from literary sources significant differences in the percentage of alien species in ports (50%) and cities (38%) were found. The number of alien species was closely related to port size, but the proportion of alien species expressed as a percentage of the total number of species did not depend significantly on port area. The proportion of alien species in both studied waterways decreased with distance from the sea and was highest in the Hungarian ports and lowest in the Czech Republic, Austria and Bavaria. Lower levels of shipping towards inland regions due to decreased river flow are likely the reason for this trend. The dissimilarity in the species composition of alien and native flora between individual river ports increased with increasing inter-port distance. Neophytes presented a stronger distance decay pattern than did either native species or archaeophytes of the Danube inland ports, potentially due to the different cargoes of individual ports, which may affect the introduction of different neophytes from different geographic areas. The results show that river ports in Central Europe should be regarded as a type of industrial area and deserve full attention with regard to the distribution and spread of alien plants

Strong password authentication with AKA authentication mechanism

This contribution discusses algorithms for strong authentication of applications in mobile devices. The current LTE and IMS networks provide strong authentication using USIM smart cards based on AKA algorithm. The problem of this authentication is that this authentication is under the sole control of Telco operators. We can expect that more applications will be placed into the IMS environment in the future. These applications will be based either on SIP (video on demand etc.) or HTTP-based protocols (e.g. as government applications or banking applications etc.). They will be provided not only by Telco operators, but also especially by independent third parties - application (content) providers (e.g. government, banks etc.). This contribution proposes new authentication algorithms that combine AKA algorithm with other authentication algorithms. Therefore, the authentication is not under the sole control of Telco operators, still using strong authentication AKA protocol

ověřování, vícefaktorové ověřování, ověřování na základě rizik, více faktorové ověřování, detekce podvodů, heslo, digitální otisk

Kontext. V současné době čelí instituce a společnosti masivním kybernetickým útokům. Útoky jsou vždy zaměřeny na určitou slabost ověřování, která je součástí konkrétního ověřovacího protokolu. V případě útoku je nutné pružně reagovat na oslabení autentizačních mechanismů. V případě útoku je nutné rychle identifikovat ovlivněný faktor autentizace a jeho důležitost dočasně oslabit. Následně je možné detekovat ovlivněnou slabost a oslabit význam pouze algoritmů zobrazujících tuto slabost. Algoritmy, které tuto slabost nevykazují, by měly zůstat beze změny. Tento článek představuje matematický model autentizace. Rychlou změnou parametrů modelu můžeme flexibilně přizpůsobit použití autentizačních prostředků situaci. Předmět. Účelem této práce je navrhnout metodu, která umožní kvantifikovat sílu (kvalitu) autentizace. Aby bylo možné dynamicky měnit metodu ověřování v závislosti na aktuálním riziku útoků. Metoda. Metodou je návrh matematického modelu a jeho simulace. Model je pak založen na součtu sil jednotlivých faktorů autentizace. K určení parametrů modelu se používá mechanismus založený na riziku. Výsledek. Příspěvek poté demonstruje výsledky simulace pomocí běžně používaných prostředků autentizace. Příspěvek poté demonstruje výsledky simulace pomocí běžně používaných prostředků ověřování: heslo, jednorázové heslo založené na hardwaru, otisk prstu zařízení, externí ověřování a kombinace těchto metod. Simulace ukázaly, že použití tohoto matematického modelu usnadňuje modelování použití prostředků autentizace. Závěry. S tímto modelem se zdá snadné modelovat různé bezpečnostní situace. Ve skutečné situaci bude nutné upřesnit parametry modelu jako součást zpětnovazebního vyhodnocení zjištěných bezpečnostních incidentů.Context. Currently, institutions and companies face massive cyber-attacks. Attacks are always focused on some authentication weakness that is part of a particular authentication protocol. In the event of an attack, it is necessary to respond flexibly to the weakening of authentication mechanisms. In the event of an attack, it is necessary to quickly identify the affected authentication factor and its importance to temporarily weaken. Subsequently, it is possible to detect the affected weakness and weaken the meaning of only the algorithms showing this weakness. Algorithms that do not show this weakness should be left unchanged. This paper introduces a mathematics model of authentication. By quick changing the model parameters, we can flexibly adapt the use of authentication means to the situation. Objective. The purpose of this work is to propose a method that will allow to quantify the strength (quality) of authentication. In order it will be possible to dynamically change the authentication method depending on the current risks of attacks. Method. The method is to design a mathematical model and its simulation. The model is then based on the sum of the strengths of the individual authentication factors. A risk-based mechanism is used to determine model parameters. Results. The paper then demonstrates the simulation results using commonly used authentication means. The paper then demonstrates the simulation results using commonly used authentication means: password, hardware based one-time password, device fingerprint, external authentication, and combination of this methods. Simulations have shown that using this mathematical model makes it easy to model the use of authentication resources. Conclusions. With this model, it seems easy to model different security situations. In the real situation, the model parameters will need to be refined as part of the feedback assessment of the established security incidents

Strong authentication for internet mobile application

4G networks to utilize Voice over LTE (VoLTE). VoLTE uses similar authentication mechanisms such as HTTP. It is therefore possible that a web client on the mobile device will use for authentication mechanism originally designed for the VoLTE [10]. I.e. to use the AKA mechanism, which uses the UICC (USIM / ISIM). This mechanism authenticates the user to the mobile network. However, Web applications can provide another entity. This contribution to discuss the possibility of strong authentication into applications running on mobile devices. It deals with the possibility of combining algorithm AKA with other authentication algorithms. Combination of two algorithms will be created strong multifactor authentication, which is suitable for applications demanding high secure authentication such as Internet banking or Internet access to the Government applications

De synantrope flora van het Rotterdamse havengebied: bijzondere vondsten en het Conyzo-Cynodontetum dactyli nieuw voor Nederland

"The synanthropic flora in the Rotterdam Port complex: selected floristic records and the plant community Conyzo-Cynodontetum dactyli new for the Netherlands This paper discuss the most significant results of a floristic and phytosociological study that was conducted in the Rotterdam Port complex in 2004. The paper presents a list of 42 synanthropic plant species that were found in the Rotterdam Port complex and introduces the association Conyzo-Cynodontetum dactyli Eliáš 1979 (the alliance Convolvulo-Agropyrion repentis Görs 1966) as a new plant community for the vegetation of the Netherlands. This association was found in Hook of Holland.

Obnovitev suhe vresave v naravnem rezervatu Zlatice (Češka republika): ocena uspešnosti paše in košnje

The vegetation of low-altitude dry heathlands in Central Europe (Euphorbio cyparissiae-Callunion vulgaris) has declined because the abandonment of traditional management has resulted in gradual overgrowth by woody species and because nutrient inputs have changed. Low-intensity grazing and sod-cutting, which are traditionally recommended to regenerate heather (Calluna vulgaris) vegetation from the seed bank, were introduced to restore stands of heather that had disappeared. The study was conducted in the Zlatnice Nature Reserve, located in the northwestern part of Prague (Czech Republic). A system of 1 m² permanent plots was used to collect the data. Both grazing and sod-cutting were effective for the restoration of the Calluna vulgaris vegetation. During the two years after the introduction of grazing, the greatest increase in the heather cover occurred in the grazed areas. The heather cover in the areas managed by sod-cutting started to increase significantly in the third year following the removal of sods and reached values comparable with the grazed areas. Regular grazing hindered the increase in the cover of herbs; the increase in the herb cover was higher after single sodcutting. Sod-cutting facilitated the expansion of mosses. The experiment suggests that non-intensive sheep and goat grazing is most likely the most appropriate tool to restore dry heathland on shallow poor soils when more than 20 years have elapsed since the disappearance of the heathland. The use of sod-cutting itself is more demanding and brings a higher risk of overgrowth by unwanted herbs and woody species, resulting in repeated degradation of the Calluna vulgaris vegetation.Vegetacija nižinskih suhih vresav v srednji Evropi (Euphorbio cyparissiae-Callunion vulgaris) je v upadanju zaradi opuščanja tradicionalnega gospodarjenja in to se kaže v postopnem zaraščanju z lesnatimi rastlinami in spremenjenem vnosu hranil. Za obnovitev sestojev z vreso, ki so izginili, smo uporabili pašo z nizko intenzivnostjo in košnjo, ki sta tradicionalno priporočena načina za obnavljanje vegetacije z vreso (Calluna vulgaris) iz semenske banke. Raziskavo smo opravili v naravnem rezervatu Zlatnice, ki se nahaja v severozahodnem delu Prage (Češka republika). Vzpostavili smo sistem stalnih 1 m² ploskev. Za obnovitev vegetacije z vrsto Calluna vulgaris sta bila uspešna tako paša kot košnja. Pokrovnost vrese se je povečala dve leti po začetku poskusa s pašo, na površinah s košnjo pa se je značilno povečala tretje leto in vrednosti so bile primerljive s pašenimi površinami. Redna paša je ovirala povečanje pokrovnosti zelišč, medtem ko se je njihova pokrovnost povečala po posamezni košnji. Košnja je tudi vplivala na povečanje pokrovnosti mahov. Poizkus je pokazal, da je slabo intenzivna paša ovac in koz verjetno najbolj primeren način obnove suhih vresav na plitvih, s hranili revnih tleh, po več kot 20 let od uničenja vresave. Košnja je bolj zahtevna, pojavlja pa se tudi možnost razraščanja nezaželjenih zelišč in lesnatih rastlin, kar zopet vodi v degradacijo vegetacije z vrsto Calluna vulgaris

Algebraic tools in autotuning principles: Relay-based autotuners

The contribution is focused on algebraic methods used in the automatic design of controller parameters. The identification of a controlled system is based on a biased relay experiment. The identified system is consecutively approximated by a low order transfer function with a time delay. The controller parameters are then computed through the solution of a Diophantine equation in the ring of proper and stable rational functions. Tuning of the controller parameters can be achieved by a pole-placement problem as a desired multiple root of the characteristic closed loop equation. This approach introduces a scalar tuning parameter which can be adjusted by several methods