922 resultados para Size- structured model
Resumo:
This data set provides a high-resolution digital elevation model (DEM) of a thermokarst depression (~7 km²) on ice-complex deposits in the Arctic Lena Delta, Siberia. The DEM based on a geodetic field survey and was used for quantitative land surface analyses and detailed description of the thermokarst depression morphology. Detailed morphometrical analyses, volume calculations, and solar radiation modeling were performed and statistically analyzed by Ulrich et al. (2010) to investigate the asymmetrical thermokarst depression development and directed lake migration previously proposed by Morgenstern et al. (2008). Furthermore, the high-resolution DEM in combination with satellite data allowed detailed analyses of spatial and temporal landscape changes due to thermokarst development (Günther, 2009).
Resumo:
This paper examines whether the IMF high interest rate policy was suitable for crisis-ridden East Asian economies. Using an "overshoot" model similar to that of Dornbusch's (1976), it shows that this sort of policy might cause an unnecessary deflationary adjusting process and have no effect on containing the real depreciation of exchange rates in the long run. The study also demonstrates that Thai economic data coincides quite well with the model presented here. Finally, it points out that the high interest policy itself might provoke high risk-premium, the existence of which, in turn, justifies the policy. This means that the policy has a self-fulfilling property. In conclusion, a "one-size-fits-all" adaptation of high interest rate policy in a currency crisis is very dangerous in general, and was inappropriate for East Asia. The desirable policy would have been to let currencies depreciate and keep interest rates stable.
Resumo:
One of the key factors behind the growth in global trade in recent decades is an increase in intermediate input as a result of the development of vertical production networks (Feensta, 1998). It is widely recognized that the formation of production networks is due to the expansion of multinational enterprises' (MNEs) activities. MNEs have been differentiated into two types according to their production structure: horizontal and vertical foreign direct investment (FDI). In this paper, we extend the model presented by Zhang and Markusen (1999) to include horizontal and vertical FDI in a model with traded intermediates, using numerical general equilibrium analysis. The simulation results show that horizontal MNEs are more likely to exist when countries are similar in size and in relative factor endowments. Vertical MNEs are more likely to exist when countries differ in relative factor endowments, and trade costs are positive. From the results of the simulation, lower trade costs of final goods and differences in factor intensity are conditions for attracting vertical MNEs.
Resumo:
To prepare an answer to the question of how a developing country can attract FDI, this paper explored the factors and policies that may help bring FDI into a developing country by utilizing an extended version of the knowledge-capital model. With a special focus on the effects of FTAs/EPAs between market countries and developing countries, simulations with the model revealed the following: (1) Although FTA/EPA generally ends to increase FDI to a developing country, the possibility of improving welfare through increased demand for skilled and unskilled labor becomes higher as the size of the country declines; (2) Because the additional implementation of cost-saving policies to reduce firm-type/trade-link specific fixed costs ends to depreciate the price of skilled labor by saving its input, a developing country, which is extremely scarce in skilled labor, is better off avoiding the additional option; (3) If a country hopes to enjoy larger welfare gains with EPA, efforts to increase skilled labor in the country, such as investing in education, may be beneficial.
Resumo:
Chinese government commits to reach its peak carbon emissions before 2030, which requires China to implement new policies. Using a CGE model, this study conducts simulation studies on the functions of an energy tax and a carbon tax and analyzes their effects on macro-economic indices. The Chinese economy is affected at an acceptable level by the two taxes. GDP will lose less than 0.8% with a carbon tax of 100, 50, or 10 RMB/ton CO2 or 5% of the delivery price of an energy tax. Thus, the loss of real disposable personal income is smaller. Compared with implementing a single tax, a combined carbon and energy tax induces more emission reductions with relatively smaller economic costs. With these taxes, the domestic competitiveness of energy intensive industries is improved. Additionally, we found that the sooner such taxes are launched, the smaller the economic costs and the more significant the achieved emission reductions.
Resumo:
This paper explores the potential usefulness of an AGE model with the Melitz-type trade specification to assess economic effects of technical regulations, taking the case of the EU ELV/RoHS directives as an example. Simulation experiments reveal that: (1) raising the fixed exporting cost to make sales in the EU market brings results that exports of the targeted commodities (motor vehicles and parts for ELV and electronic equipment for RoHS) to the EU from outside regions/countries expand while the domestic trade in the EU shrinks when the importer's preference for variety (PfV) is not strong; (2) if the PfV is not strong, policy changes that may bring reduction in the number of firms enable survived producers with high productivity to expand production to be large-scale mass producers fully enjoying the fruit of economies of scale; and (3) When the strength of the importer's PfV is changed from zero to unity, there is the value that totally changes simulation results and their interpretations.
Resumo:
Criminals are common to all societies. To fight against them the community takes different security measures as, for example, to bring about a police. Thus, crime causes a depletion of the common wealth not only by criminal acts but also because the cost of hiring a police force. In this paper, we present a mathematical model of a criminal-prone self-protected society that is divided into socio-economical classes. We study the effect of a non-null crime rate on a free-of-criminals society which is taken as a reference system. As a consequence, we define a criminal-prone society as one whose free-of-criminals steady state is unstable under small perturbations of a certain socio-economical context. Finally, we compare two alternative strategies to control crime: (i) enhancing police efficiency, either by enlarging its size or by updating its technology, against (ii) either reducing criminal appealing or promoting social classes at risk
Resumo:
The variable nature of the irradiance can produce significant fluctuations in the power generated by large grid-connected photovoltaic (PV) plants. Experimental 1 s data were collected throughout a year from six PV plants, 18 MWp in total. Then, the dependence of short (below 10 min) power fluctuation on PV plant size has been investigated. The analysis focuses on the study of fluctuation frequency as well as the maximum fluctuation value registered. An analytic model able to describe the frequency of a given fluctuation for a certain day is proposed
Resumo:
In spite of the increasing presence of Semantic Web Facilities, only a limited amount of the available resources in the Internet provide a semantic access. Recent initiatives such as the emerging Linked Data Web are providing semantic access to available data by porting existing resources to the semantic web using different technologies, such as database-semantic mapping and scraping. Nevertheless, existing scraping solutions are based on ad-hoc solutions complemented with graphical interfaces for speeding up the scraper development. This article proposes a generic framework for web scraping based on semantic technologies. This framework is structured in three levels: scraping services, semantic scraping model and syntactic scraping. The first level provides an interface to generic applications or intelligent agents for gathering information from the web at a high level. The second level defines a semantic RDF model of the scraping process, in order to provide a declarative approach to the scraping task. Finally, the third level provides an implementation of the RDF scraping model for specific technologies. The work has been validated in a scenario that illustrates its application to mashup technologies