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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Economic integration and agglomeration in a customs union in the presence of an outside region

Commendatore, Pasquale, Kubin, Ingrid, Petraglia, Carmelo, Sushko, Iryna 10 1900 (has links) (PDF)
New Economic Geography (NEG) models do not typically account for the presence of regions other than the ones involved in the integration process. We explore such a possibility in a Footloose Entrepreneur (FE) model aiming at studying the stability properties of long-run industrial location equilibria. We consider a world economy composed by a customs union of two regions (regions 1 and 2) and an "outside region" which can be regarded as the rest of the world (region 3). The effects of economic integration on industrial agglomeration within the customs union are studied under the assumption of a constant distance between the customs union itself and the third region. The results show that higher economic integration does not always implies the standard result of full agglomeration of FE models. This incomplete agglomeration outcome is due to the fact that the periphery region keeps a share of industrial activities in order to satisfy a share of "external demand". That is, the deindustrialization process brought about by economic integration in the periphery of the union is mitigated by the demand of consumers living in the rest of the world. In general, the market size of the third region affects the number of the long-run equilibria, as well as their stability properties. In addition to the standard outcomes of FE models, we describe the existence of two asymmetric equilibria characterised by unequal distribution of firms between regions 1 and 2, with no full agglomeration though. Interestingly, these equilibria are stable and therefore can be regarded as a likely long-run equilibrium state of the economy. (author's abstract) / Series: Department of Economics Working Paper Series
42

An?lise de desempenho de vendas em telecomunica??es utilizando t?cnicas de minera??o de dados / Analysis of business development in telecommunication using data minig techniques

Mattozo, Te?filo Camara 22 November 2007 (has links)
Made available in DSpace on 2014-12-17T14:52:36Z (GMT). No. of bitstreams: 1 TeofiloCM.pdf: 1145688 bytes, checksum: d9ef0be6d9fb3c2958916ee42bdb507a (MD5) Previous issue date: 2007-11-22 / Nowadays, telecommunications is one of the most dynamic and strategic areas in the world. Organizations are always seeking to find new management practices within an ever increasing competitive environment where resources are getting scarce. In this scenario, data obtained from business and corporate processes have even greater importance, although this data is not yet adequately explored. Knowledge Discovery in Databases (KDD) appears then, as an option to allow the study of complex problems in different areas of management. This work proposes both a systematization of KDD activities using concepts from different methodologies, such as CRISP-DM, SEMMA and FAYYAD approaches and a study concerning the viability of multivariate regression analysis models to explain corporative telecommunications sales using performance indicators. Thus, statistical methods were outlined to analyze the effects of such indicators on the behavior of business productivity. According to business and standard statistical analysis, equations were defined and fit to their respective determination coefficients. Tests of hypotheses were also conducted on parameters with the purpose of validating the regression models. The results show that there is a relationship between these development indicators and the amount of sales / Telecomunica??es ? uma das mais din?micas e estrat?gicas ?reas no mundo atual. H? constante necessidade das organiza??es buscarem novas formas de gerenciamento, em um ambiente cada vez mais competitivo e com recursos cada vez menores. A exist?ncia de bases de dados nas empresas passou a ter maior import?ncia. Na grande maioria dos casos, dados n?o s?o ainda explorados adequadamente. T?cnicas de Descoberta de Conhecimento em Bases de Dados (DCBD) surgem como alternativas, permitindo o estudo de problemas complexos, sendo cada vez mais utilizadas nas diferentes ?reas de gest?o. O presente trabalho apresenta uma proposta para a sistematiza??o das atividades de DCBD a qual integra as metodologias CRISP-DM, SEMMA, FAYYAD, em um ambiente interativo, bem como um estudo de viabilidade do uso de an?lise de regress?o linear m?ltipla para explica??o de vendas, no setor corporativo de telecomunica??es, utilizando indicadores de desempenho. Foi delineado um m?todo estat?stico para analisar o efeito que os indicadores de desempenho t?m sobre o comportamento da produtividade de venda. Mediante an?lises estat?sticas e comerciais criteriosas, as equa??es foram definidas, sendo ajustados os seus respectivos coeficientes de determina??o. Foram tamb?m realizados testes de hip?teses de seus par?metros, visando ? valida??o ou n?o dos modelos de regress?o e an?lise da qualidade de seus ajustamentos. Ficou evidenciada a exist?ncia de relacionamento entre as caracter?sticas desses indicadores de desempenho com o volume de vendas realizado
43

Analisi del rischio ed impatto ambientale della produzione di energia elettrica utilizzando sorgo da biomassa / RISK ASSESSMENT AND ENVIRONMENTAL IMPACT ANALYSIS OF ELECTRICITY GENERATION FROM BIOMASS SORGHUM / RISK ASSESSMENT AND ENVIRONMENTAL IMPACT ANALYSIS OF ELECTRICITY GENERATION FROM BIOMASS SORGHUM

SERRA, PAOLO 17 March 2016 (has links)
Questa tesi di dottorato analizza l’utilizzo del sorgo (Sorghum bicolour (L.) Moench) al fine di produrre energia elettrica, tramite combustione diretta della biomassa. Il focus della tesi è stato quello di sottolineare i benefici ed i rischi associati all’uso di tre genotipi di sorgo caratterizzati da diversa lunghezza del ciclo culturale (precoce, medio-tardivo e tardivo). La dinamica e la durata del processo di essicazione in campo sono state simulate attraverso un modello ad hoc (“sorghum haying model”), il quale integrato a CropSyst, è stato utilizzato per realizzare un’analisi del rischio produttivo stimando le perdite di biomassa (respirazione e meccanizzazione), ed i mancati affienamenti. Nell’analisi del rischio vengono stimati il numero di ettari necessari e la probabilità di eccedere la soglia di 64.000 ton ss anno-1 necessari per l’alimentazione di una centrale nell’Oltrepò pavese . Inoltre uno studio di Life Cycle Assessment è stato condotto per la valutazione dell’impatto ambientale dell’utilizzo del sorgo integrato a quello della paglia per il completamento del fabbisogno totale della centrale 94.000 ton ss anno-1. Particolare attenzione inoltre è stata data alla variazione del contenuto di C organico del suolo dovuto alla rimozione della paglia ed all’interramento dei mancati affienamenti di sorgo. Il genotipo precoce mostra le migliori performance produttive ed energetiche oltre che la più alta probabilità di eccedere la soglia di 64.000 ton ss anno-1. Lo studio di LCA non ha mostrato differenze significative tra i genotipi anche se il minor impatto ambientale, è stato evidenziato dal genotipo tardivo conseguenza dell’interramento della più alta quantità di mancati affienamenti. / This PhD thesis explores the use of sorghum (Sorghum bicolour (L.) Moench) as a dedicated bio-energy crop and highlights the benefits and risks associated with the use of early, medium-late and late sorghum genotypes to generate electricity by direct combustion in a biomass power plant. The dynamics and duration of the field drying process were simulated through the development of a specific model ("sorghum haying model"), which integrated with CropSyst, was used to perform a production risk assessment analysis estimating the biomass losses (respiration and mechanical), the haymaking failures and consequently to quantify the amount of dry baled biomass available for the power plant. In addition, the number of hectares needed to plant sorghum and the probability to exceed the threshold of 64000 Mg DM y-1, necessary to feed a biomass power plant in Oltrepò Pavese, were estimated. A complete Life Cycle Assessment (LCA) study was carried out in order to evaluate the environmental impact of the three sorghum genotypes involved in this study. The LCA study takes into consideration the use of winter wheat straw as an additional biomass source to satisfy the total biomass power plant needs (94000 Mg DM y-1). Particular attention was given to the soil organic C change (ΔSOC) due to straw removal and haymaking failures soil incorporation. Early genotype showed the best biomass production and energy performance as well as the highest probability to exceed the threshold of 64000 Mg DM y-1. The LCA results did not show significant differences between genotypes although the lower environmental impact, has been achieved by the late genotype due to the highest amount of haymaking failures incorporated in the soil.

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