Capacity, Fidelity, and Noise Tolerance of Associative Spatial-Temporal Memories Based on Memristive Neuromorphic Network

We have calculated the key characteristics of associative (content-addressable) spatial-temporal memories based on neuromorphic networks with restricted connectivity - "CrossNets". Such networks may be naturally implemented in nanoelectronic hardware using hybrid CMOS/memristor circuits, which may feature extremely high energy efficiency, approaching that of biological cortical circuits, at much higher operation speed. Our numerical simulations, in some cases confirmed by analytical calculations, have shown that the characteristics depend substantially on the method of information recording into the memory. Of the four methods we have explored, two look especially promising - one based on the quadratic programming, and the other one being a specific discrete version of the gradient descent. The latter method provides a slightly lower memory capacity (at the same fidelity) then the former one, but it allows local recording, which may be more readily implemented in nanoelectronic hardware. Most importantly, at the synchronous retrieval, both methods provide a capacity higher than that of the well-known Ternary Content-Addressable Memories with the same number of nonvolatile memory cells (e.g., memristors), though the input noise immunity of the CrossNet memories is somewhat lower

Physical phenomena governing the behaviour of wildfires : numerical simulation of crown fires in boreal fores

This paper presents the physical phenomena contributing to the behaviour of wildfires. The problem was formulated using a multiphase approach, including the set of balance equations governing the coupled system formed by the vegetation and the surrounding atmosphere in the vicinity of the fire front. Some numerical simulations carried out for a crown fire in boreal forest are compared to data collected during an experimental campaign conducted in the North West territories in Canada

Cation–chromatin binding as shown by ion microscopy is essential for the structural integrity of chromosomes

Mammalian interphase and mitotic cells were analyzed for their cation composition using a three-dimensional high resolution scanning ion microprobe. This instrument maps the distribution of bound and unbound cations by secondary ion mass spectrometry (SIMS). SIMS analysis of cryofractured interphase and mitotic cells revealed a cell cycle dynamics of Ca2+, Mg2+, Na+, and K+. Direct analytical images showed that all four, but no other cations, were detected on mitotic chromosomes. SIMS measurements of the total cation content for diploid chromosomes imply that one Ca2+ binds to every 12.5–20 nucleotides and one Mg2+ to every 20–30 nucleotides. Only Ca2+ was enriched at the chromosomal DNA axis and colocalized with topoisomerase IIα (Topo II) and scaffold protein II (ScII). Cells depleted of Ca2+ and Mg2+ showed partially decondensed chromosomes and a loss of Topo II and ScII, but not hCAP-C and histones. The Ca2+-induced inhibition of Topo II catalytic activity and direct binding of Ca2+ to Topo II by a fluorescent filter-binding assay supports a regulatory role of Ca2+ during mitosis in promoting solely the structural function of Topo II. Our study directly implicates Ca2+, Mg2+, Na+, and K+ in higher order chromosome structure through electrostatic neutralization and a functional interaction with nonhistone proteins

Искажение спектра сигнала протяженной цели в радаре с непрерывным частотно-модулированным сигналом

The problem of spectrum distortion in radar with a continuous frequency modulated signal (FMCW radar) is considered in the case of locating extended targets containing a large number of closely spaced reflection points. An extended target model is introduced for which a beat signal is analyzed based on its representation in the form of an amplitude-modulated oscillation. It is shown that the distortion of the spectrum occurs due to a certain relationship between the distances of the target points, the values of the carrier frequency and the deviation of the probe signal frequency. The results of numerical calculations for various values of the signal parameters and the long target model are given.En el presente artículo se aborda el problema de la distorsión del espectro en radares con señal continua de frecuencia modulada (radar FMCW) al producir objetivos prolongados que contienen un gran número de puntos de reflexión cercanos. El documento introduce un modelo de objetivo extendido para el cual se realiza un análisis de la señal de los latidos en función de su presentación en forma de oscilación de amplitud modulada. Este estudio muestra que la distorsión del espectro se produce como resultado de ciertas relaciones entre las distancias de los puntos de destino, los valores de frecuencia portadora y la frecuencia de desviación de la señal de sondeo. El artículo presenta los resultados de los cálculos numéricos para los diferentes valores de los parámetros de la señal y el modelo de objetivo extendido.No presente artigo, o problema da distorção do espectro em radares com sinal de frequência modulada contínua (radar FMCW) é abordado ao produzir objetivos prolongados que contêm um grande número de pontos de reflexão próximos. O documento introduz um modelo objetivo estendido para o qual uma análise do sinal de batimentos cardíacos é realizada de acordo com sua apresentação na forma de uma oscilação de amplitude modulada. Este estudo mostra que a distorção do espectro ocorre como resultado de certas relações entre as distâncias dos pontos de destino, os valores da freqüência da portadora e a freqüência do desvio do sinal sonoro. O artigo apresenta os resultados dos cálculos numéricos para os diferentes valores dos parâmetros do sinal e do modelo objetivo estendido.Рассмотрена проблема искажения спектра в радаре с непрерывным частотно-модулированным сигналом (FMCW радаре) при лоцировании протяженных целей, содержащих большое число близкорасположенных точек отражения. Введена модель протяженной цели, для которой проведен анализ сигнала биений на основе представления его в виде амплитудно-модулированного колебания. Показано, что искажение спектра возникает в результате определенных соотношений между расстояниями точек цели, значениями несущей частоты и частоты девиации зондирующего сигнала. Приведены результаты численных расчетов для различных значений параметров сигнала и модели протяженной цели

Sakhalin real-time shaking map tool for industrial and civil facilities safety

Regional shaking map tool for rapid characterization of the strong ground motion following the significant earthquake has been developed. New tool is based on state-of-the-art data processing technologies and regional seismological data. The earthquake data processing system uses regional and global seismic stations. The technologies for generating shaking maps is mostly automatic. Public information on recent and past earthquakes is freely available on the eqalert.ru website. Internet users can also submit the felt report through the eqalert.ru using “Did you feel the earthquake?” questioner, unified in accordance with the U.S. Geological Survey DYFI. Automatic earthquake notification is freely available in the form of PUSH-notification for Android and iOS mobile applications and Telegram messenger bot

Mathematical model of stacked one-sided arrangement of the burners

Paper is aimed at computer simulation of the turbulent methane-air combustion in upgraded U-shaped boiler unit. To reduce the temperature in the flame and hence NOx release every burner output was reduced, but the number of the burners was increased. The subject of studying: complex of characteristics with space-time fields in the upgraded steam boiler E-370 with natural circulation. The flare structure, temperature and concentrations were determined computationally

Design, Performance and Calibration of the CMS Forward Calorimeter Wedges

We report on the test beam results and calibration methods using charged particles of the CMS Forward Calorimeter (HF). The HF calorimeter covers a large pseudorapidity region (3\l |\eta| \le 5), and is essential for large number of physics channels with missing transverse energy. It is also expected to play a prominent role in the measurement of forward tagging jets in weak boson fusion channels. The HF calorimeter is based on steel absorber with embedded fused-silica-core optical fibers where Cherenkov radiation forms the basis of signal generation. Thus, the detector is essentially sensitive only to the electromagnetic shower core and is highly non-compensating (e/h \approx 5). This feature is also manifest in narrow and relatively short showers compared to similar calorimeters based on ionization. The choice of fused-silica optical fibers as active material is dictated by its exceptional radiation hardness. The electromagnetic energy resolution is dominated by photoelectron statistics and can be expressed in the customary form as a/\sqrt{E} + b. The stochastic term a is 198% and the constant term b is 9%. The hadronic energy resolution is largely determined by the fluctuations in the neutral pion production in showers, and when it is expressed as in the electromagnetic case, a = 280% and b = 11%