1,257 research outputs found

    Illegal trafficking and unsustainable waste management in Italy: evidence at the regional level

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    The presence of organized crime strongly affects sustainable waste management in Italy. In particular, illegal traf cking of waste has become one of the fastest growing areas of crime and one of the most lucrative industries among organized criminal activities, which has now in ltrated both the Italian urban and hazardous waste management cycle. In this study, we aim to investigate the determinants of the illegal traf cking of waste using waste, economic, and enforcement data in a panel analysis over the period 2002-2013. The topic is particularly relevant, given the high heterogeneity across Italian regions which also relates, and eventually leads, to different environmental performances. Our main ndings reveal that, in most Italian regions, enforcement activities do not exert a signi cant deterrence on criminal behaviors; a negative relationship between enforcement and illegal traf cking of waste can be identi ed only for very high levels of enforcement efforts. Moreover, we nd that the major determinants in uencing the rate of illegal traf cking of waste differ between northern-central and southern regions, con rming the existence of a regional dualism. In particular, while in the northern-central area the crime rate is positively related to the level of education and negatively to the adoption of environmentally sound policies, in southern regions the organized activities for illegal traf cking are negatively related to the degree of education attainment and positively to the endowment of waste management plants

    String Inspired Brane World Cosmology

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    We consider brane world scenarios including the leading correction to the Einstein-Hilbert action suggested by superstring theory, the Gauss-Bonnet term. We obtain and study the complete set of equations governing the cosmological dynamics. We find they have the same form as those in Randall-Sundrum scenarios but with time-varying four-dimensional gravitational and cosmological constants. By studying the bulk geometry we show that this variation is produced by bulk curvature terms parametrized by the mass of a black hole. Finally, we show there is a coupling between these curvature terms and matter that can be relevant for early universe cosmology

    LTV stochastic systems stabilization with large and variable input delay

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    In this paper we propose a solution to the state-feedback and output-feedback stabilization problem for linear time-varying stochastic systems affected by arbitrarily large and variable input delay. It is proved that under the proposed controller the underlying stochastic process is exponentially centered and mean square bounded. The solution is given through a set of delay differential equations with cardinality proportional to the delay bound. The predictor is based on the semigroup generated by the closed-loop system in absence of delay, and its computation is described by a numerically reliable and robust method. In the deterministic case this method generates the same optimal trajectories as in the delay-less case

    A New Class of Four-Dimensional N=1 Supergravity with Non-minimal Derivative Couplings

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    In the N=1 four-dimensional new-minimal supergravity framework, we supersymmetrise the coupling of the scalar kinetic term to the Einstein tensor. This coupling, although introduces a non-minimal derivative interaction of curvature to matter, it does not introduce harmful higher-derivatives. For this construction, we employ off-shell chiral and real linear multiplets. Physical scalars are accommodated in the chiral multiplet whereas curvature resides in a linear one.Comment: 18 pages, version published at JHE

    What is a Gene? A Two Sided View

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    The need to account for all currently available experimental observations concerning the gene nature, has reshaped the concept of gene turning it from the essentially mechanistic unit, predominant during the '70s, into a quite abstract open and generalized entity, whose contour appears less defined as compared to the past. Here we propose the essence of the gene to be considered double faced. In this respect genotypic and phenotypic entities of a gene would coexist and mix reciprocally. This harmonizes present knowledge with current definitions and predisposes for remodelling of our thinking as a consequence of future discoveries. A two sided view of the gene also allows to combine the genetic and epigenetic aspects in a unique solution, being structural and functional at the same time and simultaneously able to include the different levels in an overlapping unicum

    Parametric cost modelling of components for turbomachines: Preliminary study

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    The ever-increasing competitiveness, due to the market globalisation, has forced the industries to modify their design and production strategies. Hence, it is crucial to estimate and optimise costs as early as possible since any following changes will negatively impact the redesign effort and lead time. This paper aims to compare different parametric cost estimation methods that can be used for analysing mechanical components. The current work presents a cost estimation methodology which uses non-historical data for the database population. The database is settled using should cost data obtained from analytical cost models implemented in a cost estimation software. Then, the paper compares different parametric cost modelling techniques (artificial neural networks, deep learning, random forest and linear regression) to define the best one for industrial components. Such methods have been tested on 9 axial compressor discs, different in dimensions. Then, by considering other materials and batch sizes, it was possible to reach a training dataset of 90 records. From the analysis carried out in this work, it is possible to conclude that the machine learning techniques are a valid alternative to the traditional linear regression ones

    Preferred foliation effects in Quantum General Relativity

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    We investigate the infrared (IR) effects of Lorentz violating terms in the gravitational sector using functional renormalization group methods similar to Reuter and collaborators. The model we consider consists of pure quantum gravity coupled to a preferred foliation, described effectively via a scalar field with non-standard dynamics. We find that vanishing Lorentz violation is a UV attractive fixed-point of this model in the local potential approximation. Since larger truncations may lead to differing results, we study as a first example effects of additional matter fields on the RG running of the Lorentz violating term and provide a general argument why they are small.Comment: 12 pages, no figures, compatible with published versio
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