954 resultados para alternative economic networks
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This paper studies Spanish scientific production in Economics from 1994 to 2004. It focuses on aspects that have received little attention in other bibliometric studies, such as the impact of research and the role of scientific collaborations in the publications produced by Spanish universities. Our results show that national research networks have played a fundamental role in the increase in Spanish scientific production in this discipline.
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Tässä työssä tutkitaan haja-asutusalueiden sähkönjakeluverkkojen kehittämistä. Kehityskohteiksi on valittu viisi tekniikkaa, 1000 V-järjestelmä, keskijännitejohtojen siirtäminen teiden varsille, PAS -johtojen käyttö, maakaapelointi sekä pylväskatkaisijan käyttö. Teoreettisen tarkastelun tavoitteena on määrittää reunaehdot tarkasteltavien tekniikoiden kannattavuudelle. Aiemmin keskijänniteverkko on rakennettu lähes poikkeuksetta avojohtona. Viime vuosien myrskyt sekä lumikuormat ovat häirinneet sähkönjakelua ja nostaneet painetta jakeluvarmuuden kasvattamiseksi. Tutkimuksessa haja-asutusalueiden sähkönjakeluverkon kehittämiseen etsitään teknillisesti sekä taloudellisesti kannattavia ratkaisumalleja. Kehittämisen tavoitteena on parantaa kuluttajien sähkön laatua ja toimitusvarmuutta. Tutkimuksessa käsitellään tarkasteltavia tekniikoita esimerkkikohteiden avulla, jotka on valittu Itä-Suomelle tyypillisiltä jakelualueilta. Kohteissa taloudellista kannattavuutta tutkitaan vertaamalla perinteistä saneeraamista tarkastelussa oleviin korvaaviin menetelmiin. Korvaavilla ratkaisuilla toimitusvarmuus paranee, mutta kannattavuus riippuu siirrettävästä tehosta, asiakasryhmien jakaumasta sekä saavutettavasta vikataajuuden muutoksesta.
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ABSTRACT The traditional method of net present value (NPV) to analyze the economic profitability of an investment (based on a deterministic approach) does not adequately represent the implicit risk associated with different but correlated input variables. Using a stochastic simulation approach for evaluating the profitability of blueberry (Vaccinium corymbosum L.) production in Chile, the objective of this study is to illustrate the complexity of including risk in economic feasibility analysis when the project is subject to several but correlated risks. The results of the simulation analysis suggest that the non-inclusion of the intratemporal correlation between input variables underestimate the risk associated with investment decisions. The methodological contribution of this study illustrates the complexity of the interrelationships between uncertain variables and their impact on the convenience of carrying out this type of business in Chile. The steps for the analysis of economic viability were: First, adjusted probability distributions for stochastic input variables (SIV) were simulated and validated. Second, the random values of SIV were used to calculate random values of variables such as production, revenues, costs, depreciation, taxes and net cash flows. Third, the complete stochastic model was simulated with 10,000 iterations using random values for SIV. This result gave information to estimate the probability distributions of the stochastic output variables (SOV) such as the net present value, internal rate of return, value at risk, average cost of production, contribution margin and return on capital. Fourth, the complete stochastic model simulation results were used to analyze alternative scenarios and provide the results to decision makers in the form of probabilities, probability distributions, and for the SOV probabilistic forecasts. The main conclusion shown that this project is a profitable alternative investment in fruit trees in Chile.
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We all make decisions of varying levels of importance every day. Because making a decision implies that there are alternative choices to be considered, almost all decision involves some conflicts or dissatisfaction. Traditional economic models esteem that a person must weight the positive and negative outcomes of each option, and based on all these inferences, determines which option is the best for that particular situation. However, individuals rather act as irrational agents and tend to deviate from these rational choices. They somewhat evaluate the outcomes' subjective value, namely, when they face a risky choice leading to losses, people are inclined to have some preference for risk over certainty, while when facing a risky choice leading to gains, people often avoid to take risks and choose the most certain option. Yet, it is assumed that decision making is balanced between deliberative and emotional components. Distinct neural regions underpin these factors: the deliberative pathway that corresponds to executive functions, implies the activation of the prefrontal cortex, while the emotional pathway tends to activate the limbic system. These circuits appear to be altered in individuals with ADHD, and result, amongst others, in impaired decision making capacities. Their impulsive and inattentive behaviors are likely to be the cause of their irrational attitude towards risk taking. Still, a possible solution is to administrate these individuals a drug treatment, with the knowledge that it might have several side effects. However, an alternative treatment that relies on cognitive rehabilitation might be appropriate. This project was therefore aimed at investigate whether an intensive working memory training could have a spillover effect on decision making in adults with ADHD and in age-matched healthy controls. We designed a decision making task where the participants had to select an amount to gamble with the chance of 1/3 to win four times the chosen amount, while in the other cases they could loose their investment. Their performances were recorded using electroencephalography prior and after a one-month Dual N-Back training and the possible near and far transfer effects were investigated. Overall, we found that the performance during the gambling task was modulated by personality factors and by the importance of the symptoms at the pretest session. At posttest, we found that all individuals demonstrated an improvement on the Dual N-Back and on similar untrained dimensions. In addition, we discovered that not only the adults with ADHD showed a stable decrease of the symptomatology, as evaluated by the CAARS inventory, but this reduction was also detected in the control samples. In addition, Event-Related Potential (ERP) data are in favor of an change within prefrontal and parietal cortices. These results suggest that cognitive remediation can be effective in adults with ADHD, and in healthy controls. An important complement of this work would be the examination of the data in regard to the attentional networks, which could empower the fact that complex programs covering the remediation of several executive functions' dimensions is not required, a unique working memory training can be sufficient. -- Nous prenons tous chaque jour des décisions ayant des niveaux d'importance variables. Toutes les décisions ont une composante conflictuelle et d'insatisfaction, car prendre une décision implique qu'il y ait des choix alternatifs à considérer. Les modèles économiques traditionnels estiment qu'une personne doit peser les conséquences positives et négatives de chaque option et en se basant sur ces inférences, détermine quelle option est la meilleure dans une situation particulière. Cependant, les individus peuvent dévier de ces choix rationnels. Ils évaluent plutôt les valeur subjective des résultats, c'est-à-dire que lorsqu'ils sont face à un choix risqué pouvant les mener à des pertes, les gens ont tendance à avoir des préférences pour le risque à la place de la certitude, tandis que lorsqu'ils sont face à un choix risqué pouvant les conduire à un gain, ils évitent de prendre des risques et choisissent l'option la plus su^re. De nos jours, il est considéré que la prise de décision est balancée entre des composantes délibératives et émotionnelles. Ces facteurs sont sous-tendus par des régions neurales distinctes: le chemin délibératif, correspondant aux fonctions exécutives, implique l'activation du cortex préfrontal, tandis que le chemin émotionnel active le système limbique. Ces circuits semblent être dysfonctionnels chez les individus ayant un TDAH, et résulte, entre autres, en des capacités de prise de décision altérées. Leurs comportements impulsifs et inattentifs sont probablement la cause de ces attitudes irrationnelles face au risque. Cependant, une solution possible est de leur administrer un traitement médicamenteux, en prenant en compte les potentiels effets secondaires. Un traitement alternatif se reposant sur une réhabilitation cognitive pourrait être appropriée. Le but de ce projet est donc de déterminer si un entrainement intensif de la mémoire de travail peut avoir un effet sur la prise de décision chez des adultes ayant un TDAH et chez des contrôles sains du même âge. Nous avons conçu une tâche de prise de décision dans laquelle les participants devaient sélectionner un montant à jouer en ayant une chance sur trois de gagner quatre fois le montant choisi, alors que dans l'autre cas, ils pouvaient perdre leur investissement. Leurs performances ont été enregistrées en utilisant l'électroencéphalographie avant et après un entrainement d'un mois au Dual N-Back, et nous avons étudié les possibles effets de transfert. Dans l'ensemble, nous avons trouvé au pré-test que les performances au cours du jeu d'argent étaient modulées par les facteurs de personnalité, et par le degré des sympt^omes. Au post-test, nous avons non seulement trouvé que les adultes ayant un TDAH montraient une diminutions stable des symptômes, qui étaient évalués par le questionnaire du CAARS, mais que cette réduction était également perçue dans l'échantillon des contrôles. Les rsultats expérimentaux mesurés à l'aide de l'éléctroencéphalographie suggèrent un changement dans les cortex préfrontaux et pariétaux. Ces résultats suggèrent que la remédiation cognitive est efficace chez les adultes ayant un TDAH, mais produit aussi un effet chez les contrôles sains. Un complément important de ce travail pourrait examiner les données sur l'attention, qui pourraient renforcer l'idée qu'il n'est pas nécessaire d'utiliser des programmes complexes englobant la remédiation de plusieurs dimensions des fonctions exécutives, un simple entraiment de la mémoire de travail devrait suffire.
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This paper analyzes the impact of infrastructure investment on Spanish economic growth between 1850 and 1935. Using new infrastructure data and VAR techniques, this paper shows that the growth impact of local-scope infrastructure investment was positive, but returns to investment in large nation-wide networks were not significantly different from zero. Two complementary explanations are suggested for the last result. On the one hand, public intervention and the application of non-efficiency investment criteria were very intense in large network construction. On the other hand, returns to new investment in large networks might have decreased dramatically once the basic links were constructed.
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Due to the existence of free software and pedagogical guides, the use of Data Envelopment Analysis (DEA) has been further democratized in recent years. Nowadays, it is quite usual for practitioners and decision makers with no or little knowledge in operational research to run their own efficiency analysis. Within DEA, several alternative models allow for an environmental adjustment. Four alternative models, each user-friendly and easily accessible to practitioners and decision makers, are performed using empirical data of 90 primary schools in the State of Geneva, Switzerland. Results show that the majority of alternative models deliver divergent results. From a political and a managerial standpoint, these diverging results could lead to potentially ineffective decisions. As no consensus emerges on the best model to use, practitioners and decision makers may be tempted to select the model that is right for them, in other words, the model that best reflects their own preferences. Further studies should investigate how an appropriate multi-criteria decision analysis method could help decision makers to select the right model.
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The objective of this thesis is to provide a business model framework that connects customer value to firm resources and explains the change logic of the business model. Strategic supply management and especially dynamic value network management as its scope, the dissertation is based on basic economic theories, transaction cost economics and the resource-based view. The main research question is how the changing customer values should be taken into account when planning business in a networked environment. The main question is divided into questions that form the basic research problems for the separate case studies presented in the five Publications. This research adopts the case study strategy, and the constructive research approach within it. The material consists of data from several Delphi panels and expert workshops, software pilot documents, company financial statements and information on investor relations on the companies’ web sites. The cases used in this study are a mobile multi-player game value network, smart phone and “Skype mobile” services, the business models of AOL, eBay, Google, Amazon and a telecom operator, a virtual city portal business system and a multi-play offering. The main contribution of this dissertation is bridging the gap between firm resources and customer value. This has been done by theorizing the business model concept and connecting it to both the resource-based view and customer value. This thesis contributes to the resource-based view, which deals with customer value and firm resources needed to deliver the value but has a gap in explaining how the customer value changes should be connected to the changes in key resources. This dissertation also provides tools and processes for analyzing the customer value preferences of ICT services, constructing and analyzing business models and business concept innovation and conducting resource analysis.
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There is an increasing interest to seek new enzyme preparations for the development of new products derived from bioprocesses to obtain alternative bio-based materials. In this context, four non-commercial lipases from Pseudomonas species were prepared, immobilized on different low-cost supports, and examined for potential biotechnological applications. Results: To reduce costs of eventual scaling-up, the new lipases were obtained directly from crude cell extracts or from growth culture supernatants, and immobilized by simple adsorption on Accurel EP100, Accurel MP1000 and Celite (R) 545. The enzymes evaluated were LipA and LipC from Pseudomonas sp. 42A2, a thermostable mutant of LipC, and LipI. 3 from Pseudomonas CR611, which were produced in either homologous or heterologous hosts. Best immobilization results were obtained on Accurel EP100 for LipA and on Accurel MP1000 for LipC and its thermostable variant. Lip I. 3, requiring a refolding step, was poorly immobilized on all supports tested ( best results for Accurel MP1000). To test the behavior of immobilized lipases, they were assayed in triolein transesterification, where the best results were observed for lipases immobilized on Accurel MP1000. Conclusions: The suggested protocol does not require protein purification and uses crude enzymes immobilized by a fast adsorption technique on low-cost supports, which makes the method suitable for an eventual scaling up aimed at biotechnological applications. Therefore, a fast, simple and economic method for lipase preparation and immobilization has been set up. The low price of the supports tested and the simplicity of the procedure, skipping the tedious and expensive purification steps, will contribute to cost reduction in biotechnological lipase-catalyzed processes.
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The increasing prevalence of obesity and its associated complications requires specialized care to improve outcomes and control health care costs. Obesity is associated with numerous serious and costly medical problems requiring specialized care in managing health. The economic burden of obesity includes increased inpatient and outpatient medical expenditures as well as employer-related issues of absenteeism and associate costs. The objectives of this study are: - To describe the health consequences and the economic burden of obesity, - To review the existing treatment - To argue in favor of a specialized nutritional intervention that has shown to improve health and reduce obesity related health care costs. Therefore, expose the possibility of introducing the specialized nutrition in Switzerland and the feasibility of this project considering the medical trends and reimbursement system in Switzerland The benefits and outcomes for the patients will be the significant weight loss which reduces the severity and risk factors for complications and the improved health and quality of life. Weight loss will be a combination of a diet, exercise and behavioral interventions which are the basic recommendations for obesity treatment in addition to the specialized nutritional support. By nutritional support, we mean products that are intended to provide nutritional support in the dietary management of people with specific diseases and conditions when adequate intake of regular foods is compromised. These products are called, Food for special medical purposes FSMP. They are not intended to treat, cure, prevent, mitigate or have a direct impact on disease in a manner similar to drugs or other medical treatments and should be used under medical supervision. They also provide a low cost alternative to surgery. From a health care system perspective, the specialized nutrition will drive its advantage by reducing the utilization of medical services for obesity associated complications like medication, physician's consultations and surgical interventions arriving to a cost effective care for the hospitals, the health care organizations and the third party payers which are the health insurances. [Author, p. 4]
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Glioblastoma multiforme (GBM) is the most frequent and lethal primary brain tumor in adults. Accumulating evidence suggests that tumors comprise a hierarchical organization that is, at least partially, not genetically driven. Cells that reside at the apex of this hierarchy are commonly referred to as cancer stem cells (CSCs) and are believed to largely contribute to recurrence and therapeutic failure. Although the complexity of epigenetic regulation of the genome precludes prediction as to which epigenetic changes dominate CSC specification in different cancer types, the ability of microRNAs (miRNAs) to fine-tune expression of entire gene networks places them among prime candidates for establishing CSC properties. In this study we characterized the miRNA expression profile of primary GBM grown either under conditions that enrich for GSCs or their differentiated non-tumorigenic progeny (DGCs). Although, we identified a subset of miRNAs that was strongly differentially expressed between GSCs and DGCs, we observed that in GSCs both let-7 and, paradoxically, their target genes are highly expressed, suggesting protection against let-7 action. Using PAR-CLIP we show that insulin-like growth factor-2 mRNA-binding protein 2 (IMP2) provides a mechanism for let-7 target gene protection that represents an alternative to LIN28A/B, which abrogates let-7 biogenesis in normal embryonic and certain malignant stem cells. By direct binding to miRNA recognition elements, IMP2 protects its targets from let-7 mediated decay. Importantly, depletion of IMP2 in GSCs strongly impairs their self- renewal properties and tumorigenicity in vivo, a phenotype that can be rescued by expression of LIN28B, suggesting that IMP2 mainly contributes to GSC maintenance by protecting let-7 target genes from silencing. Using mouse models, we show that depletion of IMP2 in neural stem cells (NSCs) induces let-7 target gene down-regulation, impairs their clonogenic capacity, and affects differentiation. Taken together, our observations describe a novel regulatory function of IMP2 in the let-7 axis whereby it supports GSC and NSC specification. Résumé (Français) Le glioblastome (GBM) est la tumeur primaire maligne du cerveau la plus fréquente. De nombreuses études ont démontré l'existence d'une organisation hiérarchique des cellules cancéreuses liée à des mécanismes épigénétiques. Les cellules qui se trouvent au sommet de cette hiérarchie sont appelées cellules souches cancéreuses (CSC), et contribuent à l'échec thérapeutique. Bien que la complexité des régulateurs épigénétiques permette difficilement de prédire quel mécanisme contribue le plus aux propriétés des CSC, la capacité des microRNAs (miRNAs) de réguler des réseaux entiers de gènes, les placent comme des candidats de premiers choix. Ici, nous avons caractérisé le profil d'expression des miRNAs dans des tumeurs primaires de GBM cultivées dans des conditions qui enrichissent soit pour les CSC, soit pour leur contrepartie de cellules cancéreuses différences (CCD). De manière surprenante et paradoxale la famille de miRNA let-7 et leurs gènes cibles étaient hautement exprimés dans les CSC, suggérant un mécanisme de protection contre l'action des let-7. Avec l'aide de la technologie PAR-CLIP, nous démontrons que la protéine IMP2, protège les mRNAs de l'action des let-7 et représente une alternative à Lin28A/B, qui d'ordinaire réprime fortement la maturation des let-7 dans les cellules souches embryonnaires et divers cancers. En se liant à la région ciblée par les let-7, IMP2 protège ses transcrits de l'action de cette classe de microRNA qui est tumoro-supressive. La déplétion d'IMP2 dans des CSC de GBM réduit fortement leur clonogénicité in vitro et leur tumorigénicité in vivo. Ceci peut être reversé en introduisant Lin28B dans des CSC de GBM, suggérant qu'IMP2 exerce ses fonctions pro-tumorigéniques en modulant l'axe let-7. Avec l'aide de modèles murins, nous observons que la déplétion de IMP2 dans les cellules souches neurales (CSN) induit une baisse de leur clonogénicité et des cibles des miRNAs let-7, suggérant une conservation de ce mécanisme entre les CSC de GBM et les CSN. En résumé, nos observations définissent une nouvelle fonction de IMP2 dans l'axe let-7 par lequel il contribue au maintien des propriétés des CSC et des CSN.
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This paper studies Spanish scientific production in Economics from 1994 to 2004. It focuses on aspects that have received little attention in other bibliometric studies, such as the impact of research and the role of scientific collaborations in the publications produced by Spanish universities. Our results show that national research networks have played a fundamental role in the increase in Spanish scientific production in this discipline.
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An assortment of human behaviors is thought to be driven by rewards including reinforcement learning, novelty processing, learning, decision making, economic choice, incentive motivation, and addiction. In each case the ventral tegmental area/ventral striatum (nucleus accumbens) (VTAVS) system has been implicated as a key structure by functional imaging studies, mostly on the basis of standard, univariate analyses. Here we propose that standard functional magnetic resonance imaging analysis needs to be complemented by methods that take into account the differential connectivity of the VTAVS system in the different behavioral contexts in order to describe reward based processes more appropriately. We fi rst consider the wider network for reward processing as it emerged from animal experimentation. Subsequently, an example for a method to assess functional connectivity is given. Finally, we illustrate the usefulness of such analyses by examples regarding reward valuation, reward expectation and the role of reward in addiction.
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Strategic development of distribution networks plays a key role in the asset management in electricity distribution companies. Owing to the capital-intensive nature of the field and longspan operations of companies, the significance of a strategy is emphasised. A well-devised strategy combines awareness of challenges posed by the operating environment and the future targets of the distribution company. Economic regulation, ageing infrastructure, scarcity of resources and tightening supply requirements with challenges created by the climate change put a pressure on the strategy work. On the other hand, technology development related to network automation and underground cabling assists in answering these challenges. This dissertation aims at developing process knowledge and establishing a methodological framework by which key issues related to network development can be addressed. Moreover, the work develops tools by which the effects of changes in the operating environment on the distribution business can be analysed in the strategy work. To this end, the work discusses certain characteristics of the distribution business and describes the strategy process at a principle level. Further, the work defines the subtasks in the strategy process and presents the key elements in the strategy work and long-term network planning. The work delineates the factors having either a direct or indirect effect on strategic planning and development needs in the networks; in particular, outage costs constitute an important part of the economic regulation of the distribution business, reliability being thus a key driver in network planning. The dissertation describes the methodology and tools applied to cost and reliability analyses in the strategy work. The work focuses on determination of the techno-economic feasibility of different network development technologies; these feasibility surveys are linked to the economic regulation model of the distribution business, in particular from the viewpoint of reliability of electricity supply and allowed return. The work introduces the asset management system developed for research purposes and to support the strategy work, the calculation elements of the system and initial data used in the network analysis. The key elements of this asset management system are utilised in the dissertation. Finally, the study addresses the stages of strategic decision-making and compilation of investment strategies. Further, the work illustrates implementation of strategic planning in an actual distribution company environment.
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The objective of this paper was to evaluate the potential of neural networks (NN) as an alternative method to the basic epidemiological approach to describe epidemics of coffee rust. The NN was developed from the intensities of coffee (Coffea arabica) rust along with the climatic variables collected in Lavras-MG between 13 February 1998 and 20 April 2001. The NN was built with climatic variables that were either selected in a stepwise regression analysis or by the Braincel® system, software for NN building. Fifty-nine networks and 26 regression models were tested. The best models were selected based on small values of the mean square deviation (MSD) and of the mean prediction error (MPE). For the regression models, the highest coefficients of determination (R²) were used. The best model developed with neural networks had an MSD of 4.36 and an MPE of 2.43%. This model used the variables of minimum temperature, production, relative humidity of the air, and irradiance 30 days before the evaluation of disease. The best regression model was developed from 29 selected climatic variables in the network. The summary statistics for this model were: MPE=6.58%, MSE=4.36, and R²=0.80. The elaborated neural networks from a time series also were evaluated to describe the epidemic. The incidence of coffee rust at four previous fortnights resulted in a model with MPE=4.72% and an MSD=3.95.