177 research outputs found
BER Performance of IM/DD FSO System with OOK using APD Receiver
In this paper, the performance of intensity-modulated with direct detection (IM/DD) free space optical (FSO) system using the on-off keying (OOK) and avalanche photodiode (APD) receiver is observed. The gamma-gamma model is used to describe the effect of atmospheric turbulence since it provides good agreement in the wide range of atmospheric conditions. In addition, the same FSO system with equal gain combining applied at the reception is analyzed. After theoretical derivation of the expression for the bit error rate (BER), the numerical integration with previously specified relative calculation error is performed. Numerical results are presented and confirmed by Monte Carlo simulations. The effects of the FSO link and receiver parameters on the BER performance are discussed. The results illustrate that the optimal APD gain in the minimum BER sense depends considerably on the link distance, atmospheric turbulence strength and receiver temperature. In addition, the value of this optimal gain is slightly different in the case of spatial diversity application compared with single channel reception
(Non)dealing with the infamous past in the novel the "Reader" by Bernhard Schlink
Na primeru romana "Čitač" nemačkog autora Bernharda Šlinka u radu se uočavaju i analiziraju načini na koje se likovi (ne)suočavaju sa neslavnom nacističkom prošlošću, sa sopstvenom krivicom i krivicom svojih prethodnika. U radu se opisuju različiti postupci prihvatanja ili izmicanja od odgovornosti i krivice kojima pribegavaju likovi romana koji su bili ili direktni učesnici u nacističkim zločinima tokom Drugog svetskog rata ili pripadnici posleratnih generacija koji stiču saznanja i promišljaju o teškoj prošlosti sa kojom treba da se suoče. Cilj rada jeste ukazivanje na neophodnost bavljenja prošlošću kako bi se načini suočavanja i prihvatanja sopstvene i kolektivne krivice i odgovornosti bolje uvideli i razumeli.In the example of the novel "The Reader" by the German author Bernhard Schlink, the paper perceives and analyzes how the characters deal or do not deal with the infamous Nazi past, with their guilt and the guilt of their predecessors. The paper describes various actions of acceptance or evasion of responsibility and guilt resorted to by the characters of the novel who were either direct participants in Nazi crimes during the Second World War or members of the post-war generations who gain knowledge and reflect on the difficult past they have to face. The work aims to indicate the necessity of dealing with the past to distinguish and understand the ways of facing and accepting one's own and collective guilt and responsibility.Zbornik je rezultat istraživanja u okviru Studija Holokausta koje se pod pokrovitelјstvom Claims Conference (Conference on Jewish Material Claims Against Germany) izvode na Univerzitetu u Kragujevcu.The collection of papers is the result of research within Holocaust Studies, which are conducted at the University of Kragujevac under the support of the Claims Conference (Conference on Jewish Material Claims Against Germany)
Distribution of velocities and acceleration for a particle in Brownian correlated disorder: inertial case
We study the motion of an elastic object driven in a disordered environment
in presence of both dissipation and inertia. We consider random forces with the
statistics of random walks and reduce the problem to a single degree of
freedom. It is the extension of the mean field ABBM model in presence of an
inertial mass m. While the ABBM model can be solved exactly, its extension to
inertia exhibits complicated history dependence due to oscillations and
backward motion. The characteristic scales for avalanche motion are studied
from numerics and qualitative arguments. To make analytical progress we
consider two variants which coincide with the original model whenever the
particle moves only forward. Using a combination of analytical and numerical
methods together with simulations, we characterize the distributions of
instantaneous acceleration and velocity, and compare them in these three
models. We show that for large driving velocity, all three models share the
same large-deviation function for positive velocities, which is obtained
analytically for small and large m, as well as for m =6/25. The effect of small
additional thermal and quantum fluctuations can be treated within an
approximate method.Comment: 42 page
A Declarative Framework for Specifying and Enforcing Purpose-aware Policies
Purpose is crucial for privacy protection as it makes users confident that
their personal data are processed as intended. Available proposals for the
specification and enforcement of purpose-aware policies are unsatisfactory for
their ambiguous semantics of purposes and/or lack of support to the run-time
enforcement of policies.
In this paper, we propose a declarative framework based on a first-order
temporal logic that allows us to give a precise semantics to purpose-aware
policies and to reuse algorithms for the design of a run-time monitor enforcing
purpose-aware policies. We also show the complexity of the generation and use
of the monitor which, to the best of our knowledge, is the first such a result
in literature on purpose-aware policies.Comment: Extended version of the paper accepted at the 11th International
Workshop on Security and Trust Management (STM 2015
Reversible Random Sequential Adsorption of Dimers on a Triangular Lattice
We report on simulations of reversible random sequential adsorption of dimers
on three different lattices: a one-dimensional lattice, a two-dimensional
triangular lattice, and a two-dimensional triangular lattice with the nearest
neighbors excluded. In addition to the adsorption of particles at a rate K+, we
allow particles to leave the surface at a rate K-. The results from the
one-dimensional lattice model agree with previous results for the continuous
parking lot model. In particular, the long-time behavior is dominated by
collective events involving two particles. We were able to directly confirm the
importance of two-particle events in the simple two-dimensional triangular
lattice. For the two-dimensional triangular lattice with the nearest neighbors
excluded, the observed dynamics are consistent with this picture. The
two-dimensional simulations were motivated by measurements of Ca++ binding to
Langmuir monolayers. The two cases were chosen to model the effects of changing
pH in the experimental system.Comment: 9 pages, 10 figure
On a computer-aided approach to the computation of Abelian integrals
An accurate method to compute enclosures of Abelian integrals is developed.
This allows for an accurate description of the phase portraits of planar
polynomial systems that are perturbations of Hamiltonian systems. As an
example, it is applied to the study of bifurcations of limit cycles arising
from a cubic perturbation of an elliptic Hamiltonian of degree four
Multidimensional Homeier's generalized class and its application to planar 1D Bratu problem
[EN] In this paper, a parametric family of iterative methods for solving nonlinear systems, including Homeier’s scheme is presented, proving its third-order of convergence. The numerical section is devoted to obtain an estimation of the solution of the classical Bratu problem by transforming it in a nonlinear system by using finite differences, and solving it with different elements of the iterative family.This research was supported by Ministerio de Economía y Competitividad MTM2014-52016-C02-02.Cordero Barbero, A.; Franqués García, AM.; Torregrosa Sánchez, JR. (2015). Multidimensional Homeier's generalized class and its application to planar 1D Bratu problem. Journal of the Spanish Society of Applied Mathematics. 70(1):1-10. https://doi.org/10.1007/s40324-015-0037-xS110701Abad, M. F., Cordero, A., Torregrosa, J. R.: Fourth-and fifth-order for solving nonlinear systems of equations: an application to the global positioning system, Abstr. Appl. Anal. (2013) (Article ID 586708)Andreu, C., Cambil, N., Cordero, A., Torregrosa, J.R.: Preliminary orbit determination of artificial satellites: a vectorial sixth-order approach, Abstr. Appl. Anal. (2013) (Article ID 960582)Awawdeh, F.: On new iterative method for solving systems of nonlinear equations. Numer. Algorithms 54, 395–409 (2010)Boyd, J.P.: One-point pseudospectral collocation for the one-dimensional Bratu equation. Appl. Math. Comput. 217, 5553–5565 (2011)Bratu, G.: Sur les equation integrals non-lineaires. Bull. Math. Soc. France 42, 113–142 (1914)Buckmire, R.: Applications of Mickens finite differences to several related boundary value problems. In: Mickens, R.E. (ed.) Advances in the Applications of Nonstandard Finite Difference Schemes, pp. 47–87. World Scientific Publishing, Singapore (2005)Cordero, A., Hueso, J.L., Martínez, E., Torregrosa, J.R.: A modified Newton-Jarratt’s composition. Numer. Algorithms 55, 87–99 (2010)Gelfand, I.M.: Some problems in the theory of quasi-linear equations. Trans. Am. Math. Soc. Ser. 2, 295–381 (1963)Homeier, H.H.H.: On Newton-tyoe methods with cubic convergence. J. Comput. Appl. Math. 176, 425–432 (2005)Jacobsen, J., Schmitt, K.: The Liouville-Bratu-Gelfand problem for radial operators. J. Differ. Equ. 184, 283–298 (2002)Jalilian, R.: Non-polynomial spline method for solving Bratu’s problem. Comput. Phys. Comm. 181, 1868–1872 (2010)Kanwar, V., Kumar, S., Behl, R.: Several new families of Jarratts method for solving systems of nonlinear equations. Appl. Appl. Math. 8(2), 701–716 (2013)Mohsen, A.: A simple solution of the Bratu problem. Comput. Math. with Appl. 67, 26–33 (2014)Petković, M., Neta, B., Petković, L., Džunić, J.: Multipoint Methods for Solving Nonlinear Equations. Academic Press, Amsterdam (2013)Sharma, J.R., Guna, R.K., Sharma, R.: An efficient fourth order weighted-Newton method for systems of nonlinear equations. Numer. Algorithms 62, 307–323 (2013)Sharma, J.R., Arora, H.: On efficient weighted-Newton methods for solving systems of nonlinear equations. Appl. Math. Comput. 222, 497–506 (2013)Traub, J.F.: Iterative Methods for the Solution of Equations. Chelsea Publishing Company, New York (1982)Wan, Y.Q., Guo, Q., Pan, N.: Thermo-electro-hydrodynamic model for electrospinning process. Int. J. Nonlinear Sci. Numer. Simul. 5, 5–8 (2004
Predicted Relative Metabolomic Turnover (PRMT): determining metabolic turnover from a coastal marine metagenomic dataset
We present an approach in which the semantics of an XML language is defined by means of a transformation from an XML document model (an XML schema) to an application specific model. The application specific model implements the intended behavior of documents written in the language. A transformation is specified in a model transformation language used in the Model Driven Architecture (MDA) approach for software development. Our approach provides a better separation of three concerns found in XML applications: syntax, syntax processing logic and intended meaning of the syntax. It frees the developer of low-level syntactical details and improves the adaptability and reusability of XML applications. Declarative transformation rules and the explicit application model provide a finer control over the application parts affected by adaptations. Transformation rules and the application model for an XML language may be composed with the corresponding rules and application models defined for other XML languages. In that way we achieve reuse and composition of XML applications
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