Sobre um problema que não era interessante para Erdős

Estudamos um problema na geometria euclidiana elementar utilizando múltiplas abordagens. Concluímos que o estudo assistido por computador de hoje pode introduzir novos métodos para compreender melhor as relações e conceitos. Nomeadamente, usando as Ferramentas de Raciocínio Automático do GeoGebra, vários detalhes do problema original podem ser colocados em um contexto algébrico e, portanto, sua investigação automatizada é possível, em algum sentido, mecanicamente. Ainda assim, o pensamento criativo e a reformulação do problema em um cenário diferente continua sendo útil

Drug-therapy networks and the predictions of novel drug targets

Recently, a number of drug-therapy, disease, drug, and drug-target networks have been introduced. Here we suggest novel methods for network-based prediction of novel drug targets and for improvement of drug efficiency by analysing the effects of drugs on the robustness of cellular networks.Comment: This is an extended version of the Journal of Biology paper containing 2 Figures, 1 Table and 44 reference

COOPERATIVE MOVEMENTS SETTING EXAMPLE FOR CLASSIC TEAMWORKS OF COUNTRYSIDES IN TRANSYLVANIA

Cooperative movements assured economic welfare of villages, led them to the way of becoming real citizens in the first half of the XXth century. By that period we can say that for improving competitivity advancing coops, and their social role is necessary. In an active coop continuous modernization is needed. This is due to global challenges and multinational companies, and also smaller dominant ones. This is why Hangya cooperative organisations are to be remembered for being the first in the Carpatian basin from the late 19th century. Manufacturers can realize their interests by building their own organizations. This is the cooperation of separate farmers, today dealing with very complicated transnational organizations. Realizing these may be the way to improve livings in the countryside, especially in the agriculture. Joining the following forms of groups is a unique and necessary way to reach these. By this the conclusion is: there must be an integrated network system for production branches controlled by coops with cooperative tenets in Transylvania. For this historical examples of helping farmers remain separate, reach markets must be known and adopted into today’s circumstances.Cooperatives of Transylvania, Judiciary bases, Improving competitiveness, Integrated product channel, Security of income, Community/Rural/Urban Development, Industrial Organization,

Vodenje reševanja problemov pri pouku

We report on the results of a professional development programme involving four Hungarian teachers of mathematics. The programme aims to support teachers in integrating problem solving into their classes. The basic principle of the programme, as well as its novelty (at least compared to Hungarian practice), is that the development takes place in the teacher’s classroom, adjusted to the teacher’s curriculum and in close cooperation between the teacher and researchers. The teachers included in the programme were supported by the researchers with lesson plans, practical teaching advice and lesson analyses. The progression of the teachers was assessed after the one-year programme based on a self-designed trial lesson, focusing particularly on how the teachers plan and implement problem-solving activities in lessons, as well as on their behaviour in the classroom during problem-solving activities. The findings of this qualitative research are based on video recordings of the lessons and on the teachers’ own reflections. We claim that the worked-out lesson plans and the self-reflection habits of the teachers contribute to the successful management of problem-solving activities. (DIPF/Orig.

THE RELATIONSHIP BETWEEN MACROECONOMIC VARIABLES AND ROMANIAN CORPORATE DEFAULT RATES BETWEEN 2002-2008

During its 20 year history of market economy, Romania experienced the most severe downturn in 2009, which resulted in many cost, mainly because of the output loss. These conditions forced several firms to declare bankruptcy and to stop their activity. The aim of this research is to assess the relationship between the corporate default rates and the macroeconomic processes in the case of Romania for the period comprised between 2002Q1-2008Q4. For this, based on the relevant literature, we ranked the potential explanatory variables of the default rates into seven groups: cyclical indicators, household indicators, corporate indicators, external sector indicators, price stability indicators and interest rates, loans to private sector and finally the capital market indicators. Some studies base their results only on accounting data, others only on market data. Our study focuses on both, since this seems to be an adequate approach in capturing most of the processes. Similar to the banks' loan portfolio structure, we conducted analysis for five sectors: industry, construction, agriculture, services and the overall economy. For each sector the average default probability at time t is modeled as a logistic function of many general and sector-specific macroeconomic variables. The use of logistic regression was motivated by its ability to account for fractional data between 0 and 1. We found that at least one variable from each group has a significant explanatory power regarding the evolution of the default rates in all five sectors analyzed. In some cases the sign of the variables was the opposite of what the economic theory would have suggested, but it has to be taken into account that Romania posted the picture of an overheated economy during the analyzed period. Another important conclusion was that many variables were significant through their lagged value, which indicates an even better supervision of the evolution of the specific variables. From all the variables, the volatility of the BET-C index proves to be the most important in predicting the evolution of the default rates, as it didn't proved to be significant only for the construction sector. The evolution of FDI and the volatility of the BET-C index proved to be very important in determining the evolution of the corporate default rates, as well. The first was a very important factor in the financing of companies, especially during the analyzed period, and the risk meter is something that never should be disregarded when it comes of analyzing default rates.corporate default rate, macroeconomic processes, economic imbalances, logistic regression, lagged effects