5,362,338 research outputs found
Innovative Method of the Power Analysis
This paper describes an innovative method of the power analysis which presents the typical example of successful attacks against trusted cryptographic devices such as RFID (Radio-Frequency IDentifications) and contact smart cards. The proposed method analyzes power consumption of the AES (Advanced Encryption Standard) algorithm with neural network, which successively classifies the first byte of the secret key. This way of the power analysis is an entirely new approach and it is designed to combine the advantages of simple and differential power analysis. In the extreme case, this feature allows to determine the whole secret key of a cryptographic module only from one measured power trace. This attribute makes the proposed method very attractive for potential attackers. Besides theoretical design of the method, we also provide the first implementation results. We assume that the method will be certainly optimized to obtain more accurate classification results in the future
Power Modelling for Heterogeneous Cloud-Edge Data Centers
Existing power modelling research focuses not on the method used for
developing models but rather on the model itself. This paper aims to develop a
method for deploying power models on emerging processors that will be used, for
example, in cloud-edge data centers. Our research first develops a hardware
counter selection method that appropriately selects counters most correlated to
power on ARM and Intel processors. Then, we propose a two stage power model
that works across multiple architectures. The key results are: (i) the
automated hardware performance counter selection method achieves comparable
selection to the manual selection methods reported in literature, and (ii) the
two stage power model can predict dynamic power more accurately on both ARM and
Intel processors when compared to classic power models.Comment: 10 pages,10 figures,conferenc
A new AHP – based reactive power valuation method
In Malaysia, the electricity tariff is based on the active energy consumed and does
not include any reactive (energy) power required. In order to recover the extra cost
incurred in supplying the reactive power required by the consumers, the utility
imposes a surcharge on a consumers whose power factor averaged over a month is
below the value of 0.85pf. However, the surcharge is imposed on medium to large
commercial and industrial consumers only. This paper proposes a new method for
valuation of Reactive Power in power system. This method uses two important
factors to determine the most important Reactive Power source power system. These
two factors are: Voltage Sensitivities and Voltage Adequacy and Stability (PV
Curve). In this paper AHP method has been used to classify the Reactive power
sources according to their importance in power system. The effectiveness of the
proposed method is verified under IEEE 9-bus system
International organisation analysed with the power index method
The period of globalisation has seen more and more of international and regional organisation. Setting up an organisation with a group of state entails a resolution to the following two questions: (1) How are votes to be allocated? (2) What aggregation rule is to be employed? International and regional organisations display some interesting differences in how they have approached these two questions choosing a regime. The power index framework offers a convenient method for analysing these constitutional differences. It may be linked with the basic framework in constitutional economics – Wicksell’s classic approach, which entails that players very much use their preferences for the power to act and the power to prevent action when deciding the regime to be employed
Spectral parameter power series method for discontinuous coefficients
Let (a,b) be a finite interval and 1/p, q, r be functions from L1(a,b). We
show that a general solution (in the weak sense) of the equation (pu')'+qu =
zru on (a,b) can be constructed in terms of power series of the spectral
parameter z. The series converge uniformly on [a,b] and the corresponding
coefficients are constructed by means of a simple recursive procedure. We use
this representation to solve different types of eigenvalue problems. Several
numerical tests are discussed
Double power series method for approximating cosmological perturbations
We introduce a double power series method for finding approximate analytical
solutions for systems of differential equations commonly found in cosmological
perturbation theory. The method was set out, in a non-cosmological context, by
Feshchenko, Shkil' and Nikolenko (FSN) in 1966, and is applicable to cases
where perturbations are on sub-horizon scales. The FSN method is essentially an
extension of the well known Wentzel-Kramers-Brillouin (WKB) method for finding
approximate analytical solutions for ordinary differential equations. The FSN
method we use is applicable well beyond perturbation theory to solve systems of
ordinary differential equations, linear in the derivatives, that also depend on
a small parameter, which here we take to be related to the inverse wave-number.
We use the FSN method to find new approximate oscillating solutions in linear
order cosmological perturbation theory for a flat radiation-matter universe.
Together with this model's well known growing and decaying M\'esz\'aros
solutions, these oscillating modes provide a complete set of sub-horizon
approximations for the metric potential, radiation and matter perturbations.
Comparison with numerical solutions of the perturbation equations shows that
our approximations can be made accurate to within a typical error of 1%, or
better. We also set out a heuristic method for error estimation. A Mathematica
notebook which implements the double power series method is made available
online.Comment: 22 pages, 10 figures, 2 tables. Mathematica notebook available from
Github at https://github.com/AndrewWren/Double-power-series.gi
Shear Power Spectrum Reconstruction using Pseudo-Spectrum Method
We develop a pseudo power spectrum technique for measuring the lensing power
spectrum from weak lensing surveys in both the full sky and flat sky limits.
The power spectrum approaches have a number of advantages over the traditional
correlation function approach. We test the pseudo spectrum method by using
numerical simulations with square-shape boundary that include masked regions
with complex configuration due to bright stars and saturated spikes. Even when
25% of total area of the survey is masked, the method recovers the E-mode power
spectrum at a sub-percent precision over a wide range of multipoles
100<l<10000. The systematic error is smaller than the statistical errors
expected for a 2000 square degree survey. The residual B-mode spectrum is well
suppressed in the amplitudes at less than a percent level relative to the
E-mode. We also find that the correlated errors of binned power spectra caused
by the survey geometry effects are not significant. Our method is applicable to
the current and upcoming wide-field lensing surveys.Comment: 11 pages, 4 figures, accepted for publication in MNRA
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