Obfuscation-based malware update: A comparison of manual and automated methods

Indexación: Scopus; Web of Science.This research presents a proposal of malware classification and its update based on capacity and obfuscation. This article is an extension of [4]a, and describes the procedure for malware updating, that is, to take obsolete malware that is already detectable by antiviruses, update it through obfuscation techniques and thus making it undetectable again. As the updating of malware is generally performed manually, an automatic solution is presented together with a comparison from the standpoint of cost and processing time. The automated method proved to be more reliable, fast and less intensive in the use of resources, specially in terms of antivirus analysis and malware functionality checking times.http://univagora.ro/jour/index.php/ijccc/article/view/2961/112

Instrumentation status of the low-b magnet systems at the Large Hadron Collider (LHC)

The low-beta magnet systems are located in the Large Hadron Collider (LHC) insertion regions around the four interaction points. They are the key elements in the beams focusing/defocusing process allowing proton collisions at luminosity up to 10**34/cm**2s. Those systems are a contribution of the US-LHC Accelerator project. The systems are mainly composed of the quadrupole magnets (triplets), the separation dipoles and their respective electrical feed-boxes (DFBX). The low-beta magnet systems operate in an environment of extreme radiation, high gradient magnetic field and high heat load to the cryogenic system due to the beam dynamic effect. Due to the severe environment, the robustness of the diagnostics is primordial for the operation of the triplets. The hardware commissioning phase of the LHC was completed in February 2010. In the sake of a safer and more user-friendly operation, several consolidations and instrumentation modifications were implemented during this commissioning phase. This paper presents the instrumentation used to optimize the engineering process and operation of the final focusing/defocusing quadrupole magnets for the first years of operation.Comment: 6 pp. ICEC 23 - ICMC 2010 International Cryogenic Engineering Conference 23 - International Cryogenic Materials Conference 2010. 19-23 Jul 2010. Wroclaw, Polan

Young planets under extreme UV irradiation. I. Upper atmosphere modelling of the young exoplanet K2-33b

The K2-33 planetary system hosts one transiting ~5 R_E planet orbiting the young M-type host star. The planet's mass is still unknown, with an estimated upper limit of 5.4 M_J. The extreme youth of the system (<20 Myr) gives the unprecedented opportunity to study the earliest phases of planetary evolution, at a stage when the planet is exposed to an extremely high level of high-energy radiation emitted by the host star. We perform a series of 1D hydrodynamic simulations of the planet's upper atmosphere considering a range of possible planetary masses, from 2 to 40 M_E, and equilibrium temperatures, from 850 to 1300 K, to account for internal heating as a result of contraction. We obtain temperature profiles mostly controlled by the planet's mass, while the equilibrium temperature has a secondary effect. For planetary masses below 7-10 M_E, the atmosphere is subject to extremely high escape rates, driven by the planet's weak gravity and high thermal energy, which increase with decreasing mass and/or increasing temperature. For higher masses, the escape is instead driven by the absorption of the high-energy stellar radiation. A rough comparison of the timescales for complete atmospheric escape and age of the system indicates that the planet is more massive than 10 M_E.Comment: 11 pages, 7 figure

Tools for Quality Testing of Batches of Artifacts: The Cryogenic Thermometers for the LHC

In the processing of data series, such as in the case of the resistance R vs. temperature T calibrations of the thermometers (several thousands) necessary for the LHC new accelerator at CERN, it is necessary to use automatic methods for determining the quality of the acquired data and the degree of uniformity of the thermometer characteristics, that are of the semiconducting type. In addition, it must be determined if the calibration uncertainties comply with the specifications in the wide temperature range 1,6 - 300 K. Advantage has been taken of the fact that these thermometers represent a population with limited variability, to apply a Least Squares Method with Fixed Effect. This allows to fit the data of all the thermometers together, by taking into account the individuality of each thermometer in the model as a deviation from one of them taken as reference Ri = f(Ti) + bk0 + bk1 g(Tki) + bk1g(Tki)2 + ... where f(Ti) is the model valid for all i data and all k thermometers, while the subsequent part is the "fixed effect" model for the k-th thermometer, where g(T) is a suitable function of T. This method is shown in the paper applied to different stages of the data processing. First, for efficient compensation for the thermal drift occurring during acquisition, robust against the occurrence of outliers. Second, for detection of clusters of thermometers with inherently different characteristics. Finally, for optimisation of the calibration-point distribution

A grid of upper atmosphere models for 1--40 MEARTH planets: application to CoRoT-7 b and HD219134 b,c

There is growing observational and theoretical evidence suggesting that atmospheric escape is a key driver of planetary evolution. Commonly, planetary evolution models employ simple analytic formulae (e.g., energy limited escape) that are often inaccurate, and more detailed physical models of atmospheric loss usually only give snapshots of an atmosphere's structure and are difficult to use for evolutionary studies. To overcome this problem, we upgrade and employ an already existing upper atmosphere hydrodynamic code to produce a large grid of about 7000 models covering planets with masses 1 - 39 Earth mass with hydrogen-dominated atmospheres and orbiting late-type stars. The modeled planets have equilibrium temperatures ranging between 300 and 2000 K. For each considered stellar mass, we account for three different values of the high-energy stellar flux (i.e., low, moderate, and high activity). For each computed model, we derive the atmospheric temperature, number density, bulk velocity, X-ray and EUV (XUV) volume heating rates, and abundance of the considered species as a function of distance from the planetary center. From these quantities, we estimate the positions of the maximum dissociation and ionisation, the mass-loss rate, and the effective radius of the XUV absorption. We show that our results are in good agreement with previously published studies employing similar codes. We further present an interpolation routine capable to extract the modelling output parameters for any planet lying within the grid boundaries. We use the grid to identify the connection between the system parameters and the resulting atmospheric properties. We finally apply the grid and the interpolation routine to estimate atmospheric evolutionary tracks for the close-in, high-density planets CoRoT-7 b and HD219134 b,c...Comment: 21 pages, 4 Tables, 15 Figure

Linear Model-Based Predictive Control of the LHC 1.8 K Cryogenic Loop

The LHC accelerator will employ 1800 superconducting magnets (for guidance and focusing of the particle beams) in a pressurized superfluid helium bath at 1.9 K. This temperature is a severely constrained control parameter in order to avoid the transition from the superconducting to the normal state. Cryogenic processes are difficult to regulate due to their highly non-linear physical parameters (heat capacity, thermal conductance, etc.) and undesirable peculiarities like non self-regulating process, inverse response and variable dead time. To reduce the requirements on either temperature sensor or cryogenic system performance, various control strategies have been investigated on a reduced-scale LHC prototype built at CERN (String Test). Model Based Predictive Control (MBPC) is a regulation algorithm based on the explicit use of a process model to forecast the plant output over a certain prediction horizon. This predicted controlled variable is used in an on-line optimization procedure that minimizes an appropriate cost function to determine the manipulated variable. One of the main characteristics of the MBPC is that it can easily incorporate process constraints; therefore the regulation band amplitude can be substantially reduced and optimally placed. An MBPC controller has completed a run where performance and robustness has been compared against a standard PI controller (Proportional and Integral)

Velas solares, el futuro de la investigación espacial

Por un largo tiempo, la humanidad ha contemplado con entusiasmo el cielo y sus misterios. La observación y la curiosidad por el espacio exterior han sido siempre constantes. La busca por otros planetas, formas y civilizaciones donde la exploración del espacio es lo que despierta el deseo. Pero el desafío fue por años obtener suficiente autonomía de energía para realizar las misiones. Así, la procura de misiones que tengan una mayor autonomía es lo que se desea obtener y por consecuente, reducción del costo de la misión. Actualmente las velas solares han demostrado un gran potencial para la aplicación y la investigación. Y con los recientes avanzos en instrumentos livianos y ultralivianos en misiones que usan vela solar se ha convertido en una realidad. Este trabajo propone presentar las velas solares, desde su originaria esencia hasta los días de hoy, las misiones en actividad, los más diversos campos de investigación y los desafíos que se exhibe a la ingeniaría aeroespacial.Facultad de Ingenierí

Velas solares, el futuro de la investigación espacial

Por un largo tiempo, la humanidad ha contemplado con entusiasmo el cielo y sus misterios. La observación y la curiosidad por el espacio exterior han sido siempre constantes. La busca por otros planetas, formas y civilizaciones donde la exploración del espacio es lo que despierta el deseo. Pero el desafío fue por años obtener suficiente autonomía de energía para realizar las misiones. Así, la procura de misiones que tengan una mayor autonomía es lo que se desea obtener y por consecuente, reducción del costo de la misión. Actualmente las velas solares han demostrado un gran potencial para la aplicación y la investigación. Y con los recientes avanzos en instrumentos livianos y ultralivianos en misiones que usan vela solar se ha convertido en una realidad. Este trabajo propone presentar las velas solares, desde su originaria esencia hasta los días de hoy, las misiones en actividad, los más diversos campos de investigación y los desafíos que se exhibe a la ingeniaría aeroespacial.Facultad de Ingenierí

Non-Linear Advanced Control of the LHC Inner Triplet Heat Exchanger Test Unit

The future Large Hadron Collider (LHC) at CERN will include eight interaction region final focus magnet systems, the so-called "Inner Triplet", one on each side of the four beam collision points. The Inner Triplets will be cooled in a static bath of pressurized He II nominally at 1.9 K. This temperature is a control parameter and has very severe constraints in order to avoid the transition from the superconducting to normal resistive state. The main difference in these special zones with respect to a regular LHC cell is higher dynamic heat load unevenly distributed which modifies largely the process characteristics and hence the controller performance. Several control strategies have already been tested at CERN in a pilot plant (LHC String Test) which reproduced a LHC half-cell. In order to validate a common control structure along the whole LHC ring, a Nonlinear Model Predictive Control (NMPC) has been developed and implemented in the Inner Triplet Heat Exchanger Unit (IT-HXTU) at CERN. Automation of the Inner Triplet setup and the advanced control techniques deployed based on the Model Based Predictive Control (MBPC) principle are presented