3 resultados para Topological distribution factors
em Corvinus Research Archive - The institutional repository for the Corvinus University of Budapest
Resumo:
Several methods and indicators can be used to evaluate the coenological state of a given habitat, the ones which can be created simply, quickly, standardizably and reliably and which can be used to exactly quantify the state of a given habitat in point of numbers can be of outstanding practical importance in ecology. One possible method is the examination of the genera which can be found in a given habitat in great abundance and have little number of species and various ecological characteristics. For this purpose one of the most appropriate groups is that of ground-dwelling oribatid mites (Acari: Oribatida). In our research, joining the bioindication methodological project of the “Adaptation to Climate Change” Research Group of the Hungarian Academy of Sciences, the indication strength of genus-level taxon lists and the effects of the main pattern-generating factors creating similarity patterns were analysed with the help of data series on oribatid mites collected by us and originating from literature. Our aim was to develop a method with the help of which the difference expressed with distance functions between two oribatid mite genus lists originating from any sources can correspond to spatial and temporal scales. Our results prove that these genus lists are able to express the spatial distance of the habitats. With the help of this base of comparison changes in disturbed or transformed habitats can be expressed by means of oribatid mite communities, with spatial and temporal distances.
Resumo:
Global average temperature has increased and precipitation pattern has altered over the past 100 years due to increases in greenhouse gases. These changes will alter numerous site factors and biochemical processes of vegetative communities such as nutrient and water availability, permafrost thawing, fire regime, biotic interactions and invasion. As a consequence, climate change is expected to alter distribution ranges of many species and communities as well as boundaries of biomes. Shifting of species and vegetation zones northwards and upwards in elevation has already been observed. Besides, several experiments have been conducted and simulations have been run all over the world in order to predict possible range shifts and ecological risks. In this paper, we review literature available in Web of Science on Europe and boreal Eurasia and give an overview of observed and predicted changes in vegetation in these regions. The main trends include advance of the tree line, reduction of the alpine vegetation belt, drought risk, forest diebacks, a shift from coniferous forests to deciduous forests and invasion. It is still controversial if species migration will be able to keep pace with climate change.
Resumo:
A szerzők tanulmányukban az információbiztonság egy merőben új, minőségi változást hozó találmányával, a kvantumkulcscserével (QKD-vel – quantum key distribution) foglalkoznak. Céljuk az, hogy az újdonságra mint informatikai biztonsági termékre tekintsenek, és megvizsgálják a bevezetéséről szóló vállalati döntés során felmerülő érveket, ellenérveket. Munkájuk egyaránt műszaki és üzleti szemléletű. Előbb elkülönítik a kvantumkulcscsere hagyományos eljárásokkal szembeni használatának motiváló tényezőit, és megállapítják, milyen körülmények között szükséges a napi működésben alkalmazni. Ezt követően a forgalomban is kapható QKD-termékek tulajdonságait és gyártóit szemügyre véve megfogalmazzák a termék széles körű elterjedésének korlátait. Végül a kvantumkulcscsere-termék bevezetéséről szóló vállalati döntéshozás különböző aspektusait tekintik át. Információbiztonsági és üzleti szempontból összehasonlítják az új, valamint a hagyományosan használt kulcscsereeszközöket. Javaslatot tesznek a védendő információ értékének becslésére, amely a használatbavétel költség-haszon elemzését támaszthatja alá. Ebből levezetve megállapítják, hogy mely szervezetek alkotják a QKD lehetséges célcsoportját. Utolsó lépésként pedig arra keresik a választ, melyik időpont lehet ideális a termék bevezetésére. _____ This study aims to illuminate Quantum Key Distribution (QKD), a new invention that has the potential to bring sweeping changes to information security. The authors’ goal is to present QKD as a product in the field of IT security, and to examine several pro and con arguments regarding the installation of this product. Their work demonstrates both the technical and the business perspectives of applying QKD. First they identify motivational factors of using Quantum Key Distribution over traditional methods. Then the authors assess under which circumstances QKD could be necessary to be used in daily business. Furthermore, to evaluate the limitations of its broad spread, they introduce the vendors and explore the properties of their commercially available QKD products. Bearing all this in mind, they come out with numerous factors that can influence corporate decision making regarding the installation of QKD. The authors compare the traditional and the new tools of key distribution from an IT security and business perspective. They also take efforts to estimate the value of the pieces of information to be protected. This could be useful for a subsequent cost–benefit analysis. Their findings try to provide support for determining the target audience of QKD in the IT security market. Finally the authors attempt to find an ideal moment for an organization to invest in Quantum Key Distribution.