51,816 research outputs found
Improving the Reliability of an Electric Power System by Biomass-Fueled Gas Engine
This paper shows a practice to raise the reliability of an electric power system by the
installation of distributed generation, taking gasified biomass as fuel. To calculate the reliability index,
a probabilistic load flow was used. This index is determined as the fault probability of the system.
The resolution of this probabilistic load flow combines the method of cumulants and Gram–Charlier
expansion. To achieve the reliability index, simulating a number of contingencies is required; the
greater the number of simulated contingencies, the higher the accuracy of the index obtained. This
probabilistic technique uses the random variables as starting information, so the two generators
and loads are simulated as random variables. The generators of this distributed generation are
biomass-fueled gas engines, commonly found in Spain. The simulations carried out on the IEEE
14-bus Test System, including three biomass generators, show that the inclusion of this type of
generation improves the overall reliability indices of the electrical syste
Unbiased All-Optical Random-Number Generator
The generation of random bits is of enormous importance in modern information
science. Cryptographic security is based on random numbers which require a
physical process for their generation. This is commonly performed by hardware
random number generators. These exhibit often a number of problems, namely
experimental bias, memory in the system, and other technical subtleties, which
reduce the reliability in the entropy estimation. Further, the generated
outcome has to be post-processed to "iron out" such spurious effects. Here, we
present a purely optical randomness generator, based on the bi-stable output of
an optical parametric oscillator. Detector noise plays no role and no further
post-processing is required. Upon entering the bi-stable regime, initially the
resulting output phase depends on vacuum fluctuations. Later, the phase is
rigidly locked and can be well determined versus a pulse train, which is
derived from the pump laser. This delivers an ambiguity-free output, which is
reliably detected and associated with a binary outcome. The resulting random
bit stream resembles a perfect coin toss and passes all relevant randomness
measures. The random nature of the generated binary outcome is furthermore
confirmed by an analysis of resulting conditional entropies.Comment: 10 pages, 4 figure
On the Approximation Errors in the Frequency Test Included in the NIST SP800-22 Statistical Test Suite
In previous papers we have addressed the problem of testing Random Number Generators (RNGs) through statistical tests, with particular emphasis on the approach we called second-level testing. We have shown that this approach is capable of achieving much higher accuracy in exposing non-random generators, but may suffer from reliability issues due to approximations introduced in the test. Here we consider the NIST Frequency Test and present a mathematical expression of the error introduced by approximating the effective discrete distribution function with its continuous limit distribution. The matching against experimental data is almost perfect. © 2008 IEEE
Random Numbers Certified by Bell's Theorem
Randomness is a fundamental feature in nature and a valuable resource for
applications ranging from cryptography and gambling to numerical simulation of
physical and biological systems. Random numbers, however, are difficult to
characterize mathematically, and their generation must rely on an unpredictable
physical process. Inaccuracies in the theoretical modelling of such processes
or failures of the devices, possibly due to adversarial attacks, limit the
reliability of random number generators in ways that are difficult to control
and detect. Here, inspired by earlier work on nonlocality based and device
independent quantum information processing, we show that the nonlocal
correlations of entangled quantum particles can be used to certify the presence
of genuine randomness. It is thereby possible to design of a new type of
cryptographically secure random number generator which does not require any
assumption on the internal working of the devices. This strong form of
randomness generation is impossible classically and possible in quantum systems
only if certified by a Bell inequality violation. We carry out a
proof-of-concept demonstration of this proposal in a system of two entangled
atoms separated by approximately 1 meter. The observed Bell inequality
violation, featuring near-perfect detection efficiency, guarantees that 42 new
random numbers are generated with 99% confidence. Our results lay the
groundwork for future device-independent quantum information experiments and
for addressing fundamental issues raised by the intrinsic randomness of quantum
theory.Comment: 10 pages, 3 figures, 16 page appendix. Version as close as possible
to the published version following the terms of the journa
5G-SRNG: 5G Spectrogram-based Random Number Generation for Devices with Low Entropy Sources
Random number generation (RNG) is a crucial element in security protocols,
and its performance and reliability are critical for the safety and integrity
of digital systems. This is especially true in 5G networks with many devices
with low entropy sources. This paper proposes 5G-SRNG, an end-to-end random
number generation solution for devices with low entropy sources in 5G networks.
Compared to traditional RNG methods, the 5G-SRNG relies on hardware or software
random number generators, using 5G spectral information, such as from
spectrum-sensing or a spectrum-aware feedback mechanism, as a source of
entropy. The proposed algorithm is experimentally verified, and its performance
is analysed by simulating a realistic 5G network environment. Results show that
5G-SRNG outperforms existing RNG in all aspects, including randomness, partial
correlation and power, making it suitable for 5G network deployments.Comment: 6 Page
К вопросу о коэффициенте вариации наработки до отказа системы с последовательной структурой элементов
Рассмотрены вопросы статистического моделирования надежности невосстанавливаемой системы с последовательной структурой элементов на основе генераторов случайных чисел, имеющих -распределение. Установлена зависимость величины коэффициента вариации наработки до отказа системы от количества ее элементов.Розглянуті питання статистичного моделювання надійності невідновлювальної системи з послідовною структурою елементів на основі використання генераторів випадкових чисел, що мають -розподіл. Встановлено залежність величини коефіцієнта варіації наробітку до відмови системи від кількості її елементів.The questions of statistical modeling reliability of nonrecoverable system with consecutive structure elements based on random number generators with -distribution are considered. The dependence of the variation coefficient operating time to failure of the elements amount is determined
Influence of Experiment Design in GPA Investigating with Respect to PRNGs
This paper analyses the influence of experiment parameters onto the reliability of experiments with genetic programming algorithms. The paper is focused on the required number of experiments and especially on the influence of parallel execution which affect not only the order of thread execution but also behaviors of pseudo random number generators, which frequently do not respect recommendation of C++11 standard and are not implemented as thread safe. The observations and the effect of the suggested improvements are demonstrated on results of 720,000 experiments
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