5 resultados para On the Origin of Species
em Corvinus Research Archive - The institutional repository for the Corvinus University of Budapest
Resumo:
Climate change has serious effects on the setting up and the operation of natural ecosystems. Small increase in temperature could cause rise in the amount of some species or potential disappearance of others. During our researches, the dispersion of the species and biomass production of a theoretical ecosystem were examined on the effect of the temperature–climate change. The answers of the ecosystems which are given to the climate change could be described by means of global climate modelling and dynamic vegetation models. The examination of the operation of the ecosystems is only possible in huge centres on supercomputers because of the number and the complexity of the calculation. The number of the calculation could be decreased to the level of a PC by considering the temperature and the reproduction during modelling a theoretical ecosystem, and several important theoretical questions could be answered.
Resumo:
Kisebb bizonytalankodás után a legtöbb közgazdászhallgató a pénz funkcióinak felsorolásába kezd, ha megkérdezik, hogyan határozná meg a pénz fogalmát. A gyakorlatiasabb, vagy a számvitel iránt elkötelezettebb diákok esetleg felidézik a banki mérleget és – részben helyesen – a pénzt kötelezettségként helyezik el benne. Mintha azonban még mindig egy kicsit pironkodnánk, hogy nem találjuk a megfelelő definíciót. És ez már így megy évszázadok óta. Jelen tanulmányban két XIX. századi közgazdász – Karl Marx és Karl Menger – néhány pénzelméleti következtetését igyekszem összehasonlítani, figyelembe véve az általuk képviselt közgazdasági elmélet alapvető eltéréseit. A mára általánosan elfogadottá váló szubjektív értékelmélet és a kissé elfeledett munkaérték-elmélet látszólag teljesen eltérő feltevéseire alapozva a két gondolkodó egészen hasonló eredményre jutott. Számukra a pénz nem egy egyszerű eszköz, sem követelés és kötelezettség, ahogyan most elkönyvelnénk, hanem áru. Eredetét nem állami törvényekből vezetik le, hanem társadalmi konszenzus során létrejött jelenségnek tekintik a pénzt, ami fölötte áll a törvényeknek, eredendően nem jelképet testesít meg, hanem különleges jószágként válik alkalmassá értékjel kifejezésére. / === / If being asked how to define money most students of economics would start listing the functions of money, or those students with more practical insight would place money as liability in the balance sheet of banks. It seems, however, as if we were still embarrassed by not finding the right definition. In the present study I am endeavouring to give a brief overview of various theoretical findings on the essence of money in the economy preceding the 19th century and then compare some money theoretical conclusions of two economists – Karl Marx and Karl Menger – considering the major differences of the economic theories represented by them. On the basis of the premises of the widely accepted subjective value theory and the somewhat forgotten labour theory of value the two 19th century thinkers came to rather similar results. For them money is not a simple means of payment, nor liability or claim, the way we would account for them now, but a special commodity. They do not attach its creation to the appearance of state laws on money as a legal tender but regard it as a social phenomenon which became capable of expressing a value token due to its peculiar characteristics.
Resumo:
Climate change affects on insect populations in many ways: it can cause a shift in geographical spread, abundance, or diversity, it can change the location, the timing and the magnitude of outbreaks of pests and it can define the phenological or even the genetic properties of the species. Long-time investigations of special insect populations, simulation models and scenario studies give us very important information about the response of the insects far away and near to our century. Getting to know the potential responses of insect populations to climate change makes us possible to evaluate the adaptation of pest management alternatives as well as to formulate our future management policy. In this paper we apply two simple models, in order to introduce a complex case study for a Sycamore lace bug population. We test how the model works in case the whether conditions are very different from those in our days. Thus, besides we can understand the processes that happen in present, we can analyze the effects of a possible climate change, as well.
Resumo:
A climate envelope model was run on the distribution of four coniferous species (European silver fir, European larch, Norway spruce, and Swiss pine). The model was supported by EUFORGEN area database, ArcGIS 10 and PAST software, andREMO climate model. Prediction periods were 2011-40 and 2041-70.
Resumo:
Climate change has a great impact on the build and the work of natural ecosystems. Disappearance of some population or growth of the number in some species can be already caused by little change in temperature. A Theoretical Ecosystem Growth Model was investigated in order to examine the effects of various climate patterns on the ecological equilibrium. This paper examines the diversity of a theoretical ecosystem on the grounds of changing in temperature-climate patterns. Simulations were made from the simplest case to the more complex exercise to explain harder questions. Daily temperature values were calculated according to various functions. The effect of existing climate patterns (historical or future daily temperatures) was analysed where temperature values were from various climatic zones. In this paper it is examined what kind of environmental conditions result larger diversity related to the velocity of reproduction.