Using oceanic-atmospheric oscillations for long lead time streamflow forecasting

We present a data-driven model, Support Vector Machine (SVM), for long lead time streamflow forecasting using oceanic-atmospheric oscillations. The SVM is based on statistical learning theory that uses a hypothesis space of linear functions based on Kernel approach and has been used to predict a quantity forward in time on the basis of training from past data. The strength of SVM lies in minimizing the empirical classification error and maximizing the geometric margin by solving inverse problem. The SVM model is applied to three gages, i.e., Cisco, Green River, and Lees Ferry in the Upper Colorado River Basin in the western United States. Annual oceanic-atmospheric indices, comprising Pacific Decadal Oscillation (PDO), North Atlantic Oscillation (NAO), Atlantic Multidecadal Oscillation (AMO), and El Nino–Southern Oscillations (ENSO) for a period of 1906–2001 are used to generate annual streamflow volumes with 3 years lead time. The SVM model is trained with 86 years of data (1906–1991) and tested with 10 years of data (1992–2001). On the basis of correlation coefficient, root means square error, and Nash Sutcliffe Efficiency Coefficient the model shows satisfactory results, and the predictions are in good agreement with measured streamflow volumes. Sensitivity analysis, performed to evaluate the effect of individual and coupled oscillations, reveals a strong signal for ENSO and NAO indices as compared to PDO and AMO indices for the long lead time streamflow forecast. Streamflow predictions from the SVM model are found to be better when compared with the predictions obtained from feedforward back propagation artificial neural network model and linear regression

The organisation and financing of Russian foreign trade before 1914

SIGLEAvailable from British Library Document Supply Centre-DSC:DX193416 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Les PME et les risques de la sous-traitance industrielle à l'heure de l'assurance qualité

Une étude empirique des relations de l’entreprise multinationale Alcan avec cinq PME du Saguenay-Lac-Saint-Jean (Québec) montre que l’implantation de l’assurance qualité change considérablement les objectifs de la sous-traitance industrielle. Les acheteurs du donneur d’ordre et les entrepreneurs sous- traitants doivent concevoir différemment les risques de la sous-traitance et les moyens de s’en prémunir. Malgré les incohérences de la phase d’implantation, les PME doivent acquérir une compréhension réaliste de la stratégie poursuivie par le donneur d’ordre et des possibilités pour elles d’en tirer profit. Elles doivent aussi se préparer à négocier les ajustements structurels requis par la nouvelle coordination interfirmes et prendre conscience des risques que comporte l’assurance qualité en tant que système-expert.An empirical study of the relations between the multinational Alcan and five SBF of the Saguenay-Lac-Saint-Jean area (Quebec) shows that the objectives of industrial subcontracting are significantly modified by the implementation of quality assurance. The purchasers of the client firm and the subcontractors must develop a new vision of the risks undertaken through subcontracting and of the means of protecting themselves against these risks. Notwithstanding the inconsistencies encountered at the implementation stage, the SBF will need an adequate understanding of the strategy pursued by the client and a realist appraisal of the opportunities opened to them by this strategy. The SBF will have to negotiate the structural adjustments required by the new dynamics of inter-firm coordination and must realize that quality assurance, like any other expert system, conveys its own risks.Un estudio empírico de las relaciones de la compañía multinacional Alean con cinco PyMEs de la región de Saguenay-Lac-Saint-Jean (Quebec) muestra como la implantación del seguro de calidad modifica, de manera significativa, los objetivos de la subcontratación industrial. Los compradores de la firma contratante y los empresarios que toman el subcontrato deben pensar de manera diferente los riesgos inherentes al sistema de subcontrato y la manera de protegerse contra esos riesgos. A pesar de las incongruencias propias del período de implantación, las PyMEs deben adquirir una comprensión adecuada de la estrategia del contratante y de las ventajas que les ofrece esta estrategia. Las PyMEs deben también estar preparadas para negociar los ajustes estructurales que requiere la nueva dinámica de la coordinación entre firmas y tomar conciencia de los riesgos que comporta el seguro de calidad como sistema experto