Analytical description of muon distributions at large depths

The analytical expression for integral energy spectra and zenith angle distributions of atmospheric muons at large depths is derived. Fluctuations of muon energy losses are described using the parametrized correction factor. The fitting formula for the sea level muon spectrum at different zenith angles for spherical atmosphere is proposed. The concrete calculations for pure water are presented.Comment: Contribution to the 27th ICRC (Hamburg, August 7-15, 2001), 4 pages, 3 .eps figures, uses icrc.cl

Precise parametrizations of muon energy losses in water

The description of muon propagation through large depths of matter, based on a concept of the correction factor, is proposed. The results of Monte-Carlo calculations of this correction factor are presented. The parametrizations for continuous energy loss coefficients, valid in the broad interval of muon energies, and for the correction factor are given. The concrete calculations for pure water are presented

Atmospheric MUons from PArametric formulas: a fast GEnerator for neutrino telescopes (MUPAGE)

Neutrino telescopes will open, in the next years, new opportunities in observational high energy astrophysics. For these experiments, atmospheric muons from primary cosmic ray interactions in the atmosphere play an important role, because they provide the most abundant source of events for calibration and test. On the other side, they represent the major background source. In this paper a fast Monte Carlo generator (called MUPAGE) of bundles of atmospheric muons for underwater/ice neutrino telescopes is presented. MUPAGE is based on parametric formulas [APP25(2006)1] obtained from a full Monte Carlo simulation of cosmic ray showers generating muons in bundle, which are propagated down to 5 km w.e. It produces the event kinematics on the surface of a user-defined virtual cylinder, surrounding the detector. The multiplicity of the muons in the bundle, the muon spatial distribution and energy spectrum are simulated according to a specific model of primary cosmic ray flux, with constraints from measurements of the muon flux with underground experiments. As an example of the application, the result of the generation of events on a cylindrical surface of 3 km^2 at a depth of 2450 m of water is presented.Comment: 20 pages, 4 figure

Detection potential to point-like neutrino sources with the NEMO-km3 telescope

The NEMO Collaboration is conducting an R&D activity towards the construction of a Mediterranean km3 neutrino telescope. In this work, we present the results of Monte Carlo simulation studies on the capability of the proposed NEMO telescope to detect and identify point-like sources of high energy muon neutrinos.Comment: To be published on BCN06 proceedings (Barcelona, July 4-7, 2006

ANALYSIS OF ACOUSTIC INFORMATION PROTECTION METHODS IN CRITICAL APPLICATIONS

Subject of the study: the process of acoustic information protection in computer systems of critical applications to ensure the required level of system security. The aim of the article is to analyze the methods of acoustic information protection in computer systems of critical application by means of masking to ensure the impossibility of unauthorized access to the system. The article solves the following tasks: to analyze the software and hardware masking of speech; to study the masking of speech messages in order to introduce unrecognizability; to study the features of speech message compression; to investigate methods of covert transmission of acoustic information. The results of the work, which were obtained using mathematical methods of information transformation in computer systems, are potentially possible methods of masking speech messages to ensure the impossibility of unauthorized access to the system. The analysis of the functioning of the presented methods has led to the following conclusions. One of the perspective directions of acoustic information protection in communication channels and dedicated premises can be considered the creation and development of computerized speech masking systems along with or in conjunction with traditional technologies of semantic protection of acoustic information, namely, speech signal classification based on cryptographic algorithms. The main requirements for today's systems that provide protection of acoustic information in critical computer systems are speed and efficiency of various speech signal processing procedures using standard inexpensive technical means of computer telephony, namely: a personal computer, sound card, telephone line interface device and/or modem. These requirements can be met by applying digital methods of dynamic spectral analysis, i.e. synthesis of speech and audio signals. The choice of specific methods and means of speech masking as one of the types of semantic protection of acoustic information will depend on the practical requirements for the speech protection system and the technical characteristics of the acoustic information transmission channel. Further research is desirable to analyze the possible use of methods for synthesizing large ensembles of quasi-orthogonal discrete signals with improved ensemble, structural and correlation properties to ensure higher security indicators of acoustic channels in computer systems of critical applications