A Rough Set Based Model in Water Quality Analysis

Due to pollution caused by the expansion of human activities and economic development, water quality has gradually deteriorated in many areas of the world. Therefore, analysis of water quality becomes one of the most essential issues of modern civilization. Integrated interdisciplinary modeling techniques, providing reliable, efficient, and accurate representation of the complex phenomenon of water quality, have gained attention in recent years. With the ability to deal with both numeric and nominal information, and express knowledge in a rule-based form, the Rough Set Theory (RST) has been successfully employed in many fields. However, the application of RST has not been widely investigated in water quality analysis. The reducts generated by RST models become very time-consuming as the size of the problem increases. Using multinomial logistics regression (MLR) techniques to provide reducts of RST models, this investigation develops a hybrid Multinomial Logistic Regression and Rough Set Theory (MLRRST) model to analyze relations between degrees of water pollution and environmental factors in Taiwan. Empirical results indicate that the MLRRST model could analyze water qualities efficiently and accurately, and yield decision rules for the staff of water quality management. Thus, the proposed model is a promising and helpful scheme in analyzing water quality.     

Luft zum Atmen

Mehr Sicherheit im Umgang mit Trachealkanülen - Pflegende, die Patienten mit einer Trachealkanüle betreuen, müssen den Kanülenwechsel sicher beherrschen. Denn bei Komplikationen kann das Warten auf den Arzt katastrophale Folgen haben. Daher muss der Umgang mit den Kanülen zur Routine werden.     

Not all trade restrictions are created equally

There has been great focus in the recent trade theory literature on the introduction of firm heterogeneity into trade models. This introduction has highlighted the importance of the entry/exit decision of firms in response to changes in trade barriers. However, it is typical in many of these models to use iceberg transport costs as a general form of trade barriers that can be interchangeable with ad valorem tariffs. I show that this is not always an appropriate conclusion. Specifically, I illustrate that profit for an exporter is more elastic in response to tariffs than iceberg transport costs, which affects the entry/exit decision of firms. This has implications for welfare analysis and empirical specifications.     

Should multivariate early warning systems for banking crises pool across regions?

Most extant work on prediction of banking crises has utilised global samples, which are in turn dominated by observations from middle-income countries, and rely on a single estimator. However, economic and financial structures as well as the pattern of shocks may differ substantially across regions, while a range of specifications is desirable to check robustness. Accordingly, in this paper we test the implicit pooling assumption in earlier multivariate work on Early Warning Systems using both logit and binary recursive tree specifications separately for crises in Asia and Latin America, as well as the pooled sample. Results suggest markedly different crisis determinants across regions, implying global samples are inappropriate.