Reliability of Strategic Environmental Assessment for Territorial Management: General Criticisms and a Proposed Approach in the Presence of Relevant Accident Risk Facilities

The Strategic Environmental Assessment (SEA) is a procedure with a wide application, that has a very important role in sustainable territorial development. The aim of this work is to make some evaluations after the initial period of application also based on data of a particular complex territory, Lombardy Region (Northern Italy), which is characterized by a very high concentration of population, industrial activities and economic interests. The evaluations reveal some critical aspects that negatively influence the correct application of the SEA in Italy, with consequences on the territorial governance and the determination of expected effects corresponding to specific aims. One of these critical aspects is the need to define specific standards and parameters for carrying out a SEA on the different environmental themes. One of these is the assessment of the anthropic risk, which may initially be approximately identified as the industrial risk during territorial planning and programming. On this matter, we suggest adopting a methodological approach that is found in specific guidelines for anyone that produces the Environmental Report to support the SEA, and for councils that have to produce a Technical Examination Paper of the Relevant Accident Risk, to assess the industrial risk, also when there are companies with a relevant accident risk

On the particle paths and the stagnation points in small-amplitude deep-water waves

In order to obtain quite precise information about the shape of the particle paths below small-amplitude gravity waves travelling on irrotational deep water, analytic solutions of the nonlinear differential equation system describing the particle motion are provided. All these solutions are not closed curves. Some particle trajectories are peakon-like, others can be expressed with the aid of the Jacobi elliptic functions or with the aid of the hyperelliptic functions. Remarks on the stagnation points of the small-amplitude irrotational deep-water waves are also made.Comment: to appear in J. Math. Fluid Mech. arXiv admin note: text overlap with arXiv:1106.382

Model reduction with pole-zero placement and high order moment matching

In this paper, we compute a low order approximation of a system of large order $n$ that matches $\nu$ moments of order $j_i$ of the transfer function, at $\nu$ interpolation points, has $\ell$ poles and $k$ zeros fixed and also matches $\nu-(\ell +k)$ moments of order $j_i+1$, where $j_i+1$ is the multiplicity of the $i$-th interpolation point. We derive explicit linear systems in the free parameters to simultaneously achieve the required pole-zero placement and match the desired high order moments. We compute the closed form of the free parameters that meet the constraints, as the solution of a $\nu$ order linear system. Furthermore, for data-driven model reduction, we generalize the construction of the Loewner matrices to include the data and the imposed pole and higher order moment constraints. The resulting approximations achieve a trade-off between the good norm approximation and the preservation of the dynamics of the original system in a region of interest.Comment: 7 page

Comparison of seismic signatures of flares obtained by SOHO/MDI and GONG instruments

The first observations of seismic responses to solar flares were carried out using time-distance (TD) and holography techniques applied to SOHO/MDI Dopplergrams obtained from space and un-affected by terrestrial atmospheric disturbances. However, the ground-based network GONG is potentially a very valuable source of sunquake observations, especially in cases where space observations are unavailable. In this paper we present updated technique for pre-processing of GONG observations for application of subjacent vantage holography. Using this method and TD diagrams we investigate several sunquakes observed in association with M and X-class solar flares and compare the outcomes with those reported earlier using MDI data. In both GONG and MDI datasets, for the first time, we also detect the TD ridge associated with the September 9, 2001 flare. Our results show reassuringly positive identification of sunquakes from GONG data that can provide further information about the physics of seismic processes associated with solar flares.Comment: 19 pages, 6 figures, accepted to Astrophysical Journa

Graph complexes in deformation quantization

Kontsevich's formality theorem and the consequent star-product formula rely on the construction of an $L_\infty$-morphism between the DGLA of polyvector fields and the DGLA of polydifferential operators. This construction uses a version of graphical calculus. In this article we present the details of this graphical calculus with emphasis on its algebraic features. It is a morphism of differential graded Lie algebras between the Kontsevich DGLA of admissible graphs and the Chevalley-Eilenberg DGLA of linear homomorphisms between polyvector fields and polydifferential operators. Kontsevich's proof of the formality morphism is reexamined in this light and an algebraic framework for discussing the tree-level reduction of Kontsevich's star-product is described.Comment: 39 pages; 3 eps figures; uses Xy-pic. Final version. Details added, mainly concerning the tree-level approximation. Typos corrected. An abridged version will appear in Lett. Math. Phy