Smart meter privacy by suprression of low power frequency components

This paper focuses on the problems associated with privacy protection in smart grid. We will give an overview of a possible realization of a privacy-preserving approach that encompasses privacy-utility tradeoff into a single model. This approach proposes suppression of low power frequency components as a solution to reduce the amount of information leakage from smart meter readings. We will consider the applicability of the procedure to hide the appliance usage with respect to the type of home devices

Interval-based Recording of Generated Pseudorandom Numbers

For some applications that use pseudorandom numbers it is essential to keep the record of numbers generated so far. Such a representative example is cryptanalytic TMTO approach. In order to save the space, instead of straightforward recording of individual numbers generated, an ordered tree-like data structure which tracks the intervals of generated numbers is proposed. For estimating the memory requirements of this structure as a function of pseudorandom numbers range size, an analytical probabilistic model is established and used. This model determines the maximum number of intervals during recording which corresponds to the tree size. The result obtained from analytical model is fully validated experimentally by means of simulation for a wide spectrum of range sizes.Peer Reviewe

Evaluating Sequential Combination of Two Light-Weight Genetic Algorithm based Solutions to Intrusion Detection

In this work we have presented a genetic algorithm approach for classifying normal connections and intrusions. We have created a serial combination of two light-weight genetic algorithm-based intrusion detection systems where each of the systems exhibits certain deficiency. In this way we have managed to mitigate the deficiencies of both of them. The model was verified on KDD99 intrusion detection dataset, generating a solution competitive with the solutions reported by the state-ofthe- art, while using small subset of features from the original set that contains forty one features. The most significant features were identified by deploying principal component analysis and multi expression programming. Furthermore, our system is adaptable since it permits retraining by using new data

A Reconfigurable Array Based Prototype of a Specialised String Lookup Chip

Different strategies for performing string lookups have been developed and deployed during the evolutionary scientific process. These are the results of both the development of technology and the need for improvement of previously existing solutions. Hence, the string lookup problem has been well studied and the respectful amount of good solutions is present. Due to nature of the problem, most of the solutions are software based. Nevertheless, in the modern computing environments, in which the amount of data to be searched trough is increasingly growing, the problem re-arises demanding for the different type of approaches that could target multi-gigabit throughput rates so as to perform close to real-time string lookups. In that light, this paper studies the potential of migrating, a well-known and widely used, Boyer-Moore string lookup algorithm to a hardware specific device capable of satisfying the demanded throughput, by proposing and characterising the initial implementation option on a reconfigurable platform

Unsupervised Genetic Algorithm Deployed for Intrusion Detection

This paper represents the first step in an on-going work for designing an unsupervised method based on genetic algorithm for intrusion detection. Its main role in a broader system is to notify of an unusual traffic and in that way provide the possibility of detecting unknown attacks. Most of the machinelearning techniques deployed for intrusion detection are supervised as these techniques are generally more accurate, but this implies the need of labeling the data for training and testing which is time-consuming and error-prone. Hence, our goal is to devise an anomaly detector which would be unsupervised, but at the same time robust and accurate. Genetic algorithms are robust and able to avoid getting stuck in local optima, unlike the rest of clustering techniques. The model is verified on KDD99 benchmark dataset, generating a solution competitive with the solutions of the state-of-the-art which demonstrates high possibilities of the proposed method

Data Privacy in Smart Electricity Networks

Smart Grids are amongst the most promising future developments to manage and control the energy consumption in the next decades. However, the integration and interdependencies that will evolve between the electricity power grid, telecommunication networks and ICT enable new threats and vulnerabilities to this critical infrastructure which must be addressed adequately with the right kind of security controls, balanced risk mitigation strategies and a continuous attention towards security, privacy and regulation aspects. It is an emerging area where new data privacy problems arise as mass rollout of smart meters is already happening

Electronic aspects of formation and properties of local structures around Mn in Cd1−xMnxTe1−ySey

Local electronic and structural features around Mn in Cd1−xMnxTe0.97Se0.03 (x = 0.02; 0.05; 0.1; y = 0.03) were studied by means of X-ray Absorption Fine Structure (XAFS) techniques. Manganese ions with an average valence 2+, are found to be well incorporated into the host CdTe lattice, with clear preference for Te atoms as the first neighbors. However, Mn and Te are found to form two essentially different types of bonds, one short, strong and directional (cubic MnTe-alike bond), and three much longer, predominantly ionic in nature (hexagonal MnTe-alike bonds), thereby distorting the tetrahedral coordination around Mn. The origin of peculiar Mn–Te bonds distribution and details of their nature and strength are further elaborated by employing the first principle electronic structure calculations. That way a thorough insight in impact of the Mn–Te bond length variation on the electronic structure of the compound is obtained. The relations established between the local structures and electronic properties offer a reliable procedure for detailed analysis of the structural and electronic consequences of the 3d-transition metals (TM) incorporation in II–VI semiconductor host. Clear distinction between various influences makes the procedure easily adoptable also to the studies of TM impurities in other semiconductors

Interval-based Recording of Generated Pseudorandom Numbers

For some applications that use pseudorandom numbers it is essential to keep the record of numbers generated so far. Such a representative example is cryptanalytic TMTO approach. In order to save the space, instead of straightforward recording of individual numbers generated, an ordered tree-like data structure which tracks the intervals of generated numbers is proposed. For estimating the memory requirements of this structure as a function of pseudorandom numbers range size, an analytical probabilistic model is established and used. This model determines the maximum number of intervals during recording which corresponds to the tree size. The result obtained from analytical model is fully validated experimentally by means of simulation for a wide spectrum of range sizes

Influence of Nd3+: YAG laser irradiation on the properties of composites with carbon fibers

The carbon fiber based composites: carbon fiber reinforced plastic and 3D carbon fiber reinforced carbon composites were exposed to the Nd3+: YAG laser beams (1064 nm). Experimental parameters for the interaction of the laser beam with 1.5 Hz pulse frequency and with pulse duration 0.7 ms varied: energy density between 128 and 1915 J cm(-2), pulse energy from 1 to 3 J and mean power in the range between 0.4 and 6.5 kW. Apparently, the energy absorbed by the composite samples was mainly converted into thermal energy, causing a range of damages, from instantaneous evaporation to cracking and melting, which resulted in a crater-like damage. Program ImageJ was executed for quantitative analysis of generated damages based on micrographs obtained by SEM and light microscopes. Obtaied results enable identification of the laser induced changes in the material. (C) 2017 Elsevier Ltd. All rights reserved

Calculations of optical properties of some molecules suitable for coating of nanoparticles for biological applications

Coating of nanoparticles by various molecules is promising way to modify their surfaces and extend their bio-functionality, and infrared (IR), and spectroscopy of electronic transitions at ultraviolet and visible (UV/VIS) wavelengths are suitable techniques to investigate details of their attachment at nanoparticle surface. In the present work structure and optical properties of dextran, chitosan, oleic acid and poly(ethylene glycol) have been investigated by semi-empirical quantum mechanics, and ab initio Hartree-Fock calculations using the HyperChem (R) software package (http://www.hyper.com). The equilibrium conformations, IR, and UV/VIS spectra of molecules of various lengths, before and after their attachment to the magnetite (111) surface are determined, and IR modes and UV/VIS transitions that change the most upon the molecules attachment identified. The results are compared to the existing experimental data and the results of similar calculations, and possible implications for biological applications of nanoparticles coated with the investigated molecules have been discussed