1,288 research outputs found

    On the Consequences of Having a Central Bank with an Open Market-Policy Transmission Mechanism when a Financial Crisis hits. The case of the Federal Reserve and a Minskian Call for a Return to the Discount Window as the Primary Tool of Monetary Policy

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    This thesis analyzes the case of the Federal Reserve and highlights the negative consequences of having a Central Bank that normally prefers the open market rather than the discount window as the primary tool for the provisions of legal reserves to member financial institutions when usual private short-term credit markets get frozen. The two main negative consequences identified are from both a financial-economic efficiency point of view of the Central Bank’s lender of last resort primary responsibilities, and from a juridical-legal point of view with respect to the interpretative problems concerning the emergency liquidity Section 13(3) of the Federal Reserve Act. In light of such consequences, and adopting a Minskian perspective regarding the specific field of central banking and monetary policy, the thesis calls for a return to a Federal Reserve relying on the discount window, instead of open-market operations in its customer relationships with member financial institutions

    The Efficiency of the municipal waste management model in the Italian Municipalities

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    The role played by Public Administration in producing  local public services has been modified. This is due to the increasing of complex necessities and to the progressive evolution of the society.  So nowadays the Government is responsible for providing fundamental services in the life of any individual citizen. (Spallini S. 2014) Nevertheless in a time of recession there is a lack of financial resources. To combine these two conflicting factors the PA must be efficient in producing public services. The production of public services must be rationalized by adopting more efficient management models (Rhys A., Entwiste T. 2014). The aim of this paper is to analyse the efficiency of management in the municipal waste service in Italian cities and find a connection between the levels of efficiency and the management model adopted by the city. This study uses Data Envelopment Analysis to calculate a score for efficiency and to investigate the economies of scale in reference to management models used. We find a positive relation between dimension and efficiency, as we found more efficient management models with public capital or mixed public-private than those with only private equity capital

    Olive yield and future climate forcings

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    The rainfall reduction and the temperature increase forecasted for Mediterranean regions would likely increase the vegetation water stress and decrease productivity in rainfed agriculture. Olive trees, which have traditionally been grown under rainfed conditions, are one of the most characteristic tree crops from the Mediterranean not only for economical importance but also for minimizing erosion and desertification and for improving the carbon balance of these areas. In order to simulate how climatic change could alter soil moisture dynamics, biomass growth and fruit productivity, a water driven crop model is used in this study. The model quantitatively links olive yield to climate and soil moisture dynamics using an ecohydrological model, which simulates soil moisture, evapotranspiration and assimilation dynamics of olive orchards. The model is able to explicitly reproduce two different hydrological and climatic phases in Mediterranean areas: the well-watered conditions and the actual conditions, where the limitations induced by soil moisture availability are taken into account. Annual olive yield is obtained by integrating the carbon assimilation during the growing season, including the effects of vegetation water stress on biomass allocation. The numerical model, previously calibrated on an olive orchard located in Sicily (Italy) with a satisfactory reproduction of historical olive yield data, has been forced with future climate scenarios generated using a stochastic weather generator which allows for the downscaling of an ensemble of climate model outputs. The stochastic downscaling is carried out using simulations of some General Circulation Models adopted in the IPCC 4AR for future scenarios. In particular, 2010, 2050, 2090 and 2130 scenarios have been analyzed

    Hydrogen Production from Sea Wave for Alternative Energy Vehicles for Public Transport in Trapani (Italy)

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    The coupling of renewable energy and hydrogen technologies represents in the mid-term a very interesting way to match the tasks of increasing the reliable exploitation of wind and sea wave energy and introducing clean technologies in the transportation sector. This paper presents two different feasibility studies: the first proposes two plants based on wind and sea wave resource for the production, storage and distribution of hydrogen for public transportation facilities in theWest Sicily; the second applies the same approach to Pantelleria (a smaller island), including also some indications about solar resource. In both cases, all buses will be equipped with fuel-cells. A first economic analysis is presented together with the assessment of the avoidable greenhouse gas emissions during the operation phase. The scenarios addressed permit to correlate the demand of urban transport to renewable resources present in the territories and to the modern technologies available for the production of hydrogen from renewable energies. The study focuses on the possibility of tapping the renewable energy potential (wind and sea wave) for the hydrogen production by electrolysis. The use of hydrogen would significantly reduce emissions of particulate matter and greenhouse gases in urban districts under analysis. The procedures applied in the present article, as well as the main equations used, are the result of previous applications made in different technical fields that show a good replicability

    The Desalination Process Driven by Wave Energy: A Challenge for the Future

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    The correlation between water and energy is currently the focus of several investigations. In particular, desalination is a technological process characterized by high energy consumptionnevertheless, desalination represents the only practicable solution in several areas, where the availability of fresh water is limited but brackish water or seawater are present. These natural resources (energy and water) are essential for each otherenergy system conversion needs water, and electrical energy is necessary for water treatment or transport. Several interesting aspects include the study of saline desalination as an answer to freshwater needs and the application of renewable energy (RE) devices to satisfy electrical energy requirement for the desalination process. A merge between renewable energy and desalination is beneficial in that it is a sustainable and challenging option for the future. This work investigates the possibility of using renewable energy sources to supply the desalination process. In particular, as a case study, we analyze the application of wave energy sources in the Sicilian context.Univ Palermo UNIPA, Dept Energy Informat Engn & Math Models, I-90128 Palermo, ItalyUniv Fed Sao Paulo UNIFESP, Dept Ciencias Exatas & Terra, BR-09910720 Sao Paulo, BrazilDepartament of Ciências Exatas e da Terra, Universidade Federal de São Paulo (UNIFESP), Sao Paulo 09910-720, BrazilWeb of Scienc

    Longest Common Substring and Longest Palindromic Substring in O~(n)\tilde{\mathcal{O}}(\sqrt{n}) Time

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    The Longest Common Substring (LCS) and Longest Palindromic Substring (LPS) are classical problems in computer science, representing fundamental challenges in string processing. Both problems can be solved in linear time using a classical model of computation, by means of very similar algorithms, both relying on the use of suffix trees. Very recently, two sublinear algorithms for LCS and LPS in the quantum query model have been presented by Le Gall and Seddighin~\cite{GallS23}, requiring O~(n5/6)\tilde{\mathcal{O}}(n^{5/6}) and O~(n)\tilde{\mathcal{O}}(\sqrt{n}) queries, respectively. However, while the query model is fascinating from a theoretical standpoint, its practical applicability becomes limited when it comes to crafting algorithms meant for actual execution on real hardware. In this paper we present, for the first time, a O~(n)\tilde{\mathcal{O}}(\sqrt{n}) quantum algorithm for both LCS and LPS working in the circuit model of computation. Our solutions are simpler than previous ones and can be easily translated into quantum procedures. We also present actual implementations of the two algorithms as quantum circuits working in O(nlog5(n))\mathcal{O}(\sqrt{n}\log^5(n)) and O(nlog4(n))\mathcal{O}(\sqrt{n}\log^4(n)) time, respectively

    Detecting hydrological changes through conceptual model

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    Natural changes and human modifications in hydrological systems coevolve and interact in a coupled and interlinked way. If, on one hand, climatic changes are stochastic, non-steady, and affect the hydrological systems, on the other hand, human-induced changes due to over-exploitation of soils and water resources modifies the natural landscape, water fluxes and its partitioning. Indeed, the traditional assumption of static systems in hydrological analysis, which has been adopted for long time, fails whenever transient climatic conditions and/or land use changes occur. Time series analysis is a way to explore environmental changes together with societal changes; unfortunately, the not distinguishability between causes restrict the scope of this method. In order to overcome this limitation, it is possible to couple time series analysis with an opportune hydrological model, such as a conceptual hydrological model, which offers a schematization of complex dynamics acting within a basin. Assuming that model parameters represent morphological basin characteristics and that calibration is a way to detect hydrological signature at a specific moment, it is possible to argue that calibrating the model over different time windows could be a method for detecting potential hydrological changes. In order to test the capabilities of a conceptual model in detecting hydrological changes, this work presents different “in silico” experiments. A synthetic-basin is forced with an ensemble of possible future scenarios generated with a stochastic weather generator able to simulate steady and non-steady climatic conditions. The experiments refer to Mediterranean climate, which is characterized by marked seasonality, and consider the outcomes of the IPCC 5th report for describing climate evolution in the next century. In particular, in order to generate future climate change scenarios, a stochastic downscaling in space and time is carried out using realizations of an ensemble of General Circulation Models (GCMs) for the future scenarios 2046-2065 and 2081-2100. Land use changes (i.e. changes in the fraction of impervious area due to increasing urbanization) are explicitly simulated, while the reference hydrological responses are assessed by the spatially distributed, process-based hydrological model tRIBS, the TIN-based Real-time Integrated Basin Simulator. Several scenarios have been created, describing hypothetical centuries with steady conditions, climate change conditions, land use change conditions and finally complex conditions involving both transient climatic modifications and gradual land use changes. A conceptual lumped model, the EHSM (EcoHydrological Streamflow Model) is calibrated for the above mentioned scenarios with regard to different time-windows. The calibrated parameters show high sensitivity to anthropic variations in land use and/or climatic variability. Land use changes are clearly visible from parameters evolution especially when steady climatic conditions are considered. When the increase in urbanization is coupled with rainfall reduction the ability to detect human interventions through the analysis of conceptual model parameters is weakened

    Performances of GPM satellite precipitation over the two major Mediterranean islands

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    This study aims to assess the reliability of satellite-precipitation products from the Global Precipitation Measurements (GPM) mission in regions with complex landscape morphology. Our analysis is carried out in the European mid-latitude area, namely on the two major islands of Mediterranean Sea, i.e. Sardinia and Sicily (Italy). Both islands experience precipitation originating from the interaction of steep orography on the coasts with winds carrying humid air masses from the Mediterranean Sea. The GPM post real-time IMERG (Integrated Multi-satellitE Retrievals from Global Precipitation Measurement) “Final” run product at 0.1° spatial resolution and half-hour temporal resolution have been selected for the two-year 2015–2016 period. Evaluation and comparison ofthe selected product, withreferenceto raingauge network data, areperformed athourly and daily time scales using statistical and graphical tools. The influences of morphology and land-sea coastal area transition on the reliability of the GPM product have been analysed. Confirming previous studies, results showed that GPM satellite data slightly overestimate rainfall over the study areas, but they are well correlated with the interpolated raingauge data. Metrics based on occurrences above a given threshold and on total volume above the same threshold were applied and revealed better performances for the latter ones. Applying the same metrics we show how GPM performances improve as the temporal aggregation increases. Several drawbacks were detected in the coastal areas, which were characterized by worse performances than internal areas. Statistics are generally very similar for the two considered case studies (i.e., Sardinia and Sicily) except for correlation between topography and accuracy of GPM products, which was slightly higher for Sardinia

    Endothelial and Metabolic Function Interactions in Overweight/Obese Children.

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    AIM: Although the underlined mechanisms are still unknown, metabolic/coagulation alterations related to childhood obesity can induce vascular impairments. The aim of this study was to investigate the relationship between metabolic/coagulation parameters and endothelial function/vascular morphology in overweight/obese children. METHODS: Thirty-five obese/overweight children (22 pre-pubertal, mean age: 9.52±3.35 years) were enrolled. Body mass index (BMI), homeostasis model assessment index (HOMAIR), metabolic and coagulation parameters, [adiponectin, fibrinogen, high molecular weight adiponectin (HMW), endothelin-1, and vonWillebrand factor antigen] ultrasound early markers of atherosclerosis [flow-mediated dilatation (FMD), common carotid intima-media thickness (C-IMT), and anteroposterior diameter of infra-renal abdominal aorta (APAO)] were assessed. RESULTS: APAO was related to anthropometric (age: r=0.520, p=0.001; height: r=0.679, p<0.001; weight: r=0.548, p=0.001; BMI: r=0.607, p<0.001; SBP: r=0.377, p=0.026) and metabolic (HOMAIR: r=0.357, p=0.035; HMW: r=-0.355, p=0.036) parameters. Age, height, and systolic blood pressure were positively related to increased C-IMT (r=0.352, p=0.038; r=0.356, p=0.036; r=0.346, p=0.042, respectively). FMD was not related to any clinical and biochemical characteristics of the pediatric population. Age, HOMAIR, fasting glucose levels, and HMW were independent predictors for APAO increase. Each unit decrease in HMW concentrations (1 μg/ml) induced a 0.065 mm increase in APAO. CONCLUSION: High molecular weight adiponectin is related to cardiovascular risk in overweight/obese children
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