990 research outputs found

    Capital market inefficiencies, credit rationing and lending relationship in SME's

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    The financing of small-medium enterprises (SME' s) shows a great dependence on short term borrowing from banking institutions and savings banks. The causes of this situation are basically due to low credit availability at the stage of the firm' s life cycle when it requires the greatest access. A seminal paper by Fazzari, Hubbard and Petersen (1988) has served as the basis for important subsequent research. In Spain conclusions drawn by studies in this area mostly agree that the basic reason for the aboye mentioned low credit availability is high borrowing costs due to market imperfections which inevitably lead to credit ratioIĂšng. The aim of this paper is twofold. First, to study the roles of firm-creditor relationships (Berger and Udell, 1992,1995; Petersen and Rajan, 1994, 1995) and Loan Guarantee Associations [LGA] in reducing information asymmetries in loan contracts and, second, to attempt to ascertain whether these factors are among the determining factors of loan rates for SME's

    Application to small-scale field of Steinernema riobravis Cabanillas, Poinar and Raulston, 1994 (Nematoda, steinernematidae), thermo trilogy strain against Neocurtilla claraziana (Saussure, 1874) (Orthoptera, Gryllotalpidae) in gardens of La Plata, Argent

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    Fil: Reboredo, Guillermo R.. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Cátedra de Fisiología Animal; ArgentinaFil: Camino, Nora Beatriz. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios en Parasitología y Vectores (CEPAVE); Argentin

    The Economic Case for Landscape Restoration in Latin America

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    Degraded lands—lands that have lost some degree of their natural productivity through human activity—account for over 20 percent of forest and agricultural lands in Latin America and the Caribbean. Some 300 million hectares of the region's forests are considered degraded, and about 350 million hectares are now classified as deforested. The agriculture and forestry sectors are growing and exerting great pressure on natural areas. With the region expected to play an increasingly important role in global food security, this pressure will continue to ratchet up. In addition, land degradation is a major driver in greenhouse gas emissions in the region. Forest and landscape restoration can offer a solution to these increasing pressures

    Management education in Ibero-America : an exploratory analysis and perspective

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    Considering the importance of management education for society and the pedagogical inadequacies that pose a threat to academic institutions, this article develops an exploratory approach for evaluating and monitoring the quality of management education within an Ibero American context. Latin American countries and Spain tend to think of themselves as an Ibero American region, so the overview of key issues in management education in this article is pertinent to the entire region. The data is important to policymakers who wish to enhance the quality of higher education, since well trained managers contribute to successful business strategies and superior organizational performance. Unfortunately, there is almost no empirical work available on the performance and effectiveness of higher education in Ibero American countries. Our study helps bridge that gap by providing useful data for evaluating and reflecting upon some of the variables associated with management education in a sample of Ibero American universities.Publicad

    Logique floue Appliquée à la gestion à long terme des ressources en eau

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    Dans le contexte de la rareté des ressources en eau, une approche globale de la gestion à long terme d'un système de stockage/transfert/distribution d'eau est proposée. L'objectif principal de la gestion d'un tel type de système est de gérer les réserves et les délestages de manière à minimiser les écarts entre offre et demande, ceci à partir d'une prédiction de la demande et des apports.Ainsi, on propose une approche à horizon glissant et surtout une procédure d'adaptation des pondérations du critère fondée sur la logique floue. Cette notion d'adaptation du critère parait tout à fait judicieuse quand on connaît la difficulté de définir les pondérations de tels problèmes d'optimisation et son influence sur la pertinence de la solution obtenue. On vérifie ici l'apport essentiel de la logique floue qui permet d'appréhender finement les enjeux en présence dans la gestion de long terme du système stockage/transfert/distribution d'eau. Le problème de gestion à long terme est résolu par une heuristique améliorée utilisant la programmation linéaire et la programmation dynamique pour réduire les effets de la discrétisation spatiale qui est si limitative dans ce contexte.L'approche de gestion proposée est effectivement appliquée à un cas d'étude qui permet de mettre en évidence sa relative simplicité de mise en œuvre.Since the origins of history, irrigation of agricultural lands has been reported to be an activity of great concern for many human societies. At the beginning, natural irrigation systems such as the Nile River flowing through the sands of Egypt have provided to neighbouring populations some amenities in their hard life. However irregular cycles of floods and droughts were a serious impediment to permanent settlements and to a continuous improvement of life conditions. Consequently human ingenuity has been continuously challenged by the development of new ways and means to master water resource system (WRS).During the last century, improved civil engineering techniques and the development of digital control systems and techniques have dramatically increased the power of human societies over their water resources. However many problems, which received some attention in the past, now require new approaches, given the steady increase in water demand and the introduction of environmental conservation considerations. Today, intelligent systems techniques appear to be able to give some insight in this direction by improving the efficiency of the different decision steps involved in the management and control of such systems. This paper focuses on the problem of the long-term management of a water resource system composed of a network of dams and river reaches. This system is viewed as a hybrid dynamic system, called here a storage/transfer/distribution system. The main long-term management objective of such a system is to manage reserves and releases so as to minimise the deficit between supply and demand by taking into account predictions of demand and contributions.Thus, in the present context of water resource scarcity, a complete approach for long-term management of a storage/transfer/distribution system is proposed. To take into account major uncertainties related to the operations of this kind of system, a sliding horizon approach (it consists of readjusting each week the release plan over the whole coming year, according to the present reserves, the most recent long-term demand estimation and the programmed release for the next week). In addition, an adaptation procedure of weighting parameters of the minimisation criterion based on fuzzy logic is implemented. The definition of an optimisation objective function is in this case a very intricate question since it involves competition, uncertainty and geographical dispersion. However, it is crucial to guarantee the quality of long-term management. This is why Fuzzy Logic is used as a particularly appropriate means to refine on-line the formulation of the objective function of the recurrent optimisation problem. Fuzzy Logic is also shown to be very useful in defining what is at stake in the long-term management. This criterion adaptation concept seems judicious, in view of the difficulty of defining the weighting parameters of such optimisation problems and their influence on the relevant solution obtained.The long-term management problem is solved with improved heuristics using linear programming and dynamic programming in order to reduce the effects of spatial discretisation, which is so restrictive in this context. The suggested approach is applied to a case study, which highlights its relative simplicity of implementation

    Fast local search for fuzzy job shop scheduling

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    In the sequel, we propose a new neighbourhood structure for local search for the fuzzy job shop scheduling problem. This is a variant of the well-known job shop problem, with uncertainty in task durations modelled using fuzzy numbers and where the goal is to minimise the expected makespan of the resulting schedule. The new neighbourhood structure is based in changing the relative order of subsequences of tasks within critical blocks. We study its theoretical properties and provide a makespan estimate which allows to select only feasible neighbours while covering a greater portion of the search space than a previous neighbourhood from the literature. Despite its larger search domain, experimental results show that this new structure notably reduces the computational load of local search with respect to the previous neighbourhood while maintaining or even improving solution quality

    Enhanced memetic search for reducing energy consumption in fuzzy flexible job shops

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    The flexible job shop is a well-known scheduling problem that has historically attracted much research attention both because of its computational complexity and its importance in manufacturing and engineering processes. Here we consider a variant of the problem where uncertainty in operation processing times is modeled using triangular fuzzy numbers. Our objective is to minimize the total energy consumption, which combines the energy required by resources when they are actively processing an operation and the energy consumed by these resources simply for being switched on. To solve this NP-Hard problem, we propose a memetic algorithm, a hybrid metaheuristic method that combines global search with local search. Our focus has been on obtaining an efficient method, capable of obtaining similar solutions quality-wise to the state of the art using a reduced amount of time. To assess the performance of our algorithm, we present an extensive experimental analysis that compares it with previous proposals and evaluates the effect on the search of its different components.Supported by the Spanish Government under research grants PID2019-106263RB-I00 and TED2021-131938B-I00 and by Universidad de Cantabria and the Government of Cantabria under Grant ConcepciĂłn Arenal UC-20-20

    Biodiversity of mermitids (Nematoda: mermithidae) parasitoids of aquatic diptera (Simuliidae, culicidae and chironomidae) in Argentina

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    Fil: Camino, Nora Beatriz. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios en Parasitología y Vectores (CEPAVE); ArgentinaFil: González, Sandra Elizabeth. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios en Parasitología y Vectores (CEPAVE); ArgentinaFil: Reboredo, Guillermo R.. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Cátedra de Fisiología Animal; Argentin
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