Papers by Mario Mango Furnari
International Journal of High Speed Computing, 1999
We present the first systematic investigation of the [Ne v] (14 m/24 m) and [S iii] (18 m/33 m) i... more We present the first systematic investigation of the [Ne v] (14 m/24 m) and [S iii] (18 m/33 m) infrared line flux ratios, traditionally used to estimate the density of the ionized gas, in a sample of 41 type 1 and type 2 active galactic nuclei (AGNs) observed with the Infrared Spectrograph on board Spitzer. The majority of galaxies with both [Ne v] lines detected have observed [Ne v] line flux ratios consistent with or below the theoretical low-density limit, based on calculations using currently available collision strengths and ignoring absorption and stimulated emission. We find that type 2 AGNs have lower line flux ratios than type 1 AGNs and that all of the galaxies with line flux ratios below the low-density limit are type 2 AGNs. We argue that differential infrared extinction to the [Ne v] emitting region due to dust in the obscuring torus is responsible for the ratios below the low-density limit and we suggest that the ratio may be a tracer of the inclination angle of the torus to our line of sight. Because the temperature of the gas, the amount of extinction, and the effect of absorption and stimulated emission on the line ratios are all unknown, we are not able to determine the electron densities associated with the [Ne v] line flux ratios for the objects in our sample. We also find that the [S iii] emission from the galaxies in our sample is extended and originates primarily in star-forming regions. Since the emission from low-ionization species is extended, any analysis using line flux ratios from such species obtained from slits of different sizes is invalid for most nearby galaxies.
Proceedings of SPIE, Jan 15, 2006
A corporate information system needs to be as accessible as library content, which implies to org... more A corporate information system needs to be as accessible as library content, which implies to organize the content in a logical structure, categorizing it, and using the categories to add metadata to the information. Content Management System (CMS) are an emerging kind software component that manages content, usually making a large use of the web technologies, whose main goals are to allow easy creation, publishing and retrieval of content to fit business needs. The focus of this paper is to describe how we integrated "map" metaphor into a CMS. Where maps are symbolic information and rely on the use of a graphic sign language. A characteristic feature of maps is that their design has traditionally been constrained by the need to create one model of reality for a variety of purposes. The map's primary role as a communication medium involves the application of processes such as selection, classification, displacement, symbolization and graphic exaggeration. A model of the infrastructure is presented and the current prototype of the model is briefly discussed together the currently deployed environment for the cultural heritage information dissemination.
Springer eBooks, 2019
Representation Theorem for Linear Forms. Let ψ : V → R be linear. Then there exists a unique vect... more Representation Theorem for Linear Forms. Let ψ : V → R be linear. Then there exists a unique vector a such that ψ(v) = a • v for every v ∈ V. Note. Similar statements are true for many abstract inner product spaces! Definition. A tensor is a linear transformation from V into V. Note. In general a tensor is a multilinear form from a vector space into R, but our book uses tensor, as above, to always mean a "tensor of type
In this chapter the classical relativistic formulation of physical laws is analyzed. We begin by ... more In this chapter the classical relativistic formulation of physical laws is analyzed. We begin by recalling the fundamental principles of classical mechanics, since the great revolution produced by special and general relativity cannot be fully appreciated without a complete understanding of the ideas of classical physics.
In Chap. 7, the relativistic balance equations of momentum and energy were stated for a single ma... more In Chap. 7, the relativistic balance equations of momentum and energy were stated for a single material point. In Chap. 8, these equations have been formulated in Minkowski spacetime, i.e., in tensor form. In this chapter we formulate the relativistic equations of a continuous system S, showing that they can be • obtained by adopting different points of view, and • formulated in tensor form in Minkowski spacetime. We begin with a very simple model of incoherent matter that describes the behavior of a continuous system S in which there is no interaction among the parts of S. Then we consider the more realistic case of fluid or elastic systems, and we sketch the different paths leading to the above-mentioned equations. Finally, we formulate the thermodynamics of a continuous system evolving in the presence of irreversible thermal phenomena. 9.1 Relativistic Equations for Incoherent Matter Consider a continuous system S moving relative to the inertial frame of reference I , and suppose that its material content is distributed with density in the region C(t). Denote by x a point of S and by δc an elementary material neighborhood of x. Finally, let I (x) be the proper frame of the particle x. Then the mass δc contained in δc, relative to the observer I , and the mass δc, relative to the proper frame I (x), satisfy the relativistic condition γ v δc = δc,
In Chap. 7 we described the procedures that in special relativity allow us to derive the physical... more In Chap. 7 we described the procedures that in special relativity allow us to derive the physical laws relative to an inertial frame starting from their 4-dimensional formulation and vice versa. Determining analogous procedures in general relativity is a more difficult task. In this chapter, we analyze reasonable criteria leading to the relative formulation of physical laws starting from their 4-dimensional formulation. By this approach we determine the momentum equation and the energy equation of a material point relative to an arbitrary frame of reference starting from the four-dimensional momentum–energy equation. Then we compare the obtained equation with similar equations proposed in the literature. Finally, the above procedure is applied to derive the relative charge conservation, Maxwell’s equations, and the balance equations of an incoherent fluid (For the content of this chapter, see the review paper [142]).
In this chapter the two milestones on which Einstein based the special theory of relativity (see ... more In this chapter the two milestones on which Einstein based the special theory of relativity (see [42]) are presented: the principle of optical isotropy and the principle of special relativity. Further, we describe how the contradictions emerging from the efforts carried out to unify the theories of electrodynamics and mechanics were solved in a new physical framework. In this framework, time plays a role completely different from the role it had in classical mechanics. The special and general Lorentz transformations are presented, and many of their important physical consequences are discussed.
Einstein’s equations are nonlinear, and this makes it very difficult to exhibit their explicit so... more Einstein’s equations are nonlinear, and this makes it very difficult to exhibit their explicit solutions. In order to obtain some solutions, we can adopt one of two points of view: search for approximate solutions or impose symmetries on spacetime that can be justified by physical motivations.
In Chap. 14, some models of the universe that can be considered reasonable representations of a r... more In Chap. 14, some models of the universe that can be considered reasonable representations of a region of the universe have been described. In this chapter, general relativity is applied to cosmology.
WORLD SCIENTIFIC eBooks, 1994
Run-time methods for parallelizing Do loops, L. Rauchwerger and D. Padua a theoretical comparison... more Run-time methods for parallelizing Do loops, L. Rauchwerger and D. Padua a theoretical comparison of static versus dynamic scheduling for massively parallel machines, F. Gasperoni and U. Schwiegelshohn adaptive and integrated hardware/software data prefetching for shared-memory multi-processors, E.H. Gornish and A. Veidenbaum portable parallelization of the ECMWF's weather forecast program, U. Gartel et al a hypergraph-based model for port allocation on VLIW architectures, A. Capitanio et al performance evaluation of routing methods in a massively parallel machine, K. Khoumsi and G. Mazare an analytic model for a hierarchical parallel system, K. Joe and A. Fukuda Non Von - parallel programming language extensions for imperative languages, T. Lewis why high performance Fortran is not useful for advanced numerical applications - directions for future development, H. Zima a parallel edge linking algorithm using the Hough transform, T. Johansson and E. Bengtsson a parallel environment for cellular automata network simulation, M. Furnari et al. (Part Contents).
Initially the book was published without the Extra Supplementary Material. Now it has been includ... more Initially the book was published without the Extra Supplementary Material. Now it has been included in chapter 1, titled "Tensor Algebra".
In Chap. 14 we showed that the exterior Schwarzschild solution of Einstein’s equation describes t... more In Chap. 14 we showed that the exterior Schwarzschild solution of Einstein’s equation describes the gravitational field outside a static spherical mass with constant mass density. This solution has the peculiar characteristic that some components of the metric tensor became infinite at the Schwarzschild radius \(r_{s}=2m\) and at \(r=0\). The nature and meaning of this behavior was not quite understood at the time of its discovery (1916), although the bending of light and the redshift of clocks in a gravitational field were phenomena already acquired.
In this chapter we analyze the geometric formulation of special relativity proposed by Hermann Mi... more In this chapter we analyze the geometric formulation of special relativity proposed by Hermann Minkowski in 1907 (see [109]), two years after the publication of Albert Einstein’s famous paper on the special theory of relativity.
The principle of special relativity states that all optically isotropic frames of reference are e... more The principle of special relativity states that all optically isotropic frames of reference are equivalent for the description of physical phenomena. In other words, two optically isotropic observers I and \(I^{\prime }\) register the same results when they carry out measurements by identical experimental devices in the same physical conditions.
There are two complementary ways to use Einstein’s equations: $$\begin{aligned} G_{\alpha \beta }... more There are two complementary ways to use Einstein’s equations: $$\begin{aligned} G_{\alpha \beta } = -\chi \, T_{\alpha \beta }. \end{aligned}$$ After choosing a momentum–energy tensor on the basis of some physical assumptions, we can try to determine the solutions of Einstein’s equations corresponding to that momentum–energy tensor. For example, if the momentum–energy tensor of a perfect fluid is chosen and a spherically symmetric solution is searched for, then a reasonable stellar model is obtained.
In Chap. 9 we analyzed the relativistic formulation of a continuous distribution of matter S in t... more In Chap. 9 we analyzed the relativistic formulation of a continuous distribution of matter S in the presence of thermal phenomena. In this chapter we propose to extend the results of Chap. 9 to the case of a charged mass distribution. To achieve this goal we must answer the following questions: How do we write Maxwell’s equations in matter? How do we describe the interaction between electromagnetic fields and matter?
In this chapter, the one-parameter transformation groups and Lie derivative are defined. Furtherm... more In this chapter, the one-parameter transformation groups and Lie derivative are defined. Furthermore, two fundamental topics of differential geometry are presented in introductory form: exterior derivative and integration of r-forms. The exterior derivative extends to r-forms the elementary definitions of gradient of a function, curl, and divergence of a vector field as well as the meaning of exact and closed 1-forms. The integration of r-forms allows one to extend the definitions of surface and volume integrals as well as the theorems of Gauss and Stokes.
In this paper we review symbolic parallel programming issues. We start describing the peculiariti... more In this paper we review symbolic parallel programming issues. We start describing the peculiarities of symbolic programming. Next, we review the standard parallel programming framework for the imperative-like languages. Also the autoscheduling environment, proposed by Polychronopoulos (1990), is introduced. The current extensions for symbolic parallel programming are described. The problem how to efficiently manage the parallelism in LISP is addressed, and the Hierarchical Task Graph, an intermediate program representation in which the parallelism is expressed by the task hierarchy, and the associated run-time model are also described. The extensions necessary to manage the parallelism at run-time in a multiprogramming environment are described.<<ETX>>
ABSTRACT In this paper we describe an approach to coping with parallelism in symbolic application... more ABSTRACT In this paper we describe an approach to coping with parallelism in symbolic applications. Our purpose is to build a parallel symbolic system suited to homogenous and heterogenous Distributed Memory Parallel Systems. In particular we describe the design criteria and the implementation strategy for a Distributed Lisp System (DLISP) that relies on a client/server model and uses a functional level mechanism to synchronize and to control the processes. The intraprocess and interprocess management are obtained using the notion of continuation of a computation for process context switching and resuming. In this way this system does not rely on any control feature outside the LISP language. The DLISP system is structured in three main layers. The hardware heterogeneity is encapsulated using the Parallel Virtual Machine software package to implement the actual communication among processes
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Papers by Mario Mango Furnari