Switching median filter for suppressing multi-pixel impulse noise

This paper proposes a new switching median filter for suppressing multi-pixel impulse noise in X-ray images. A multi-pixel impulse is understood as a set of several neighboring pixels, the intensity of each significantly exceeds background intensity. Multi-pixel noise can occur, for example, due to the blooming effect, the reason being the limited value of pixel saturation capacity. This article defines the thresholds for the intensity increment relative to the eight immediate neighbors, above which the current pixel is processed by the median filter. The dependence of these thresholds on the number of pixels in an impulse is presented. The proposed algorithm is based on the median filtering process, which consists of several iterations. In this case, the filter has the smallest possible size, which minimizes image distortion during processing. In particular, to exclude a single-pixel impulse, pixel processing is turned on when intensity surge exceeds 3.5 with the grayscale value ranging from 0 to 1. At the same time, to exclude nine-pixel impulses, three iterations are required with the following thresholds: the first iteration with a threshold 2.0; the second iteration also with a threshold 2.0 and the third iteration with a threshold 3.5. The algorithm proposed was tested on real X-ray images corrupted by multi-pixel impulse noise. The algorithm is not only simple, but also reliable and suitable for real-time implementation and application. The efficiency of the technique is shown in comparison with other known filtering methods with respect to the degree of noise suppression. The main result of the testing is that only the proposed method allows excluding multi-pixel noise. Other advantage of the algorithm is its weak effect on the level of Gaussian noise leading to the absence of image blurring (or preserving image details) during processing.The research has been carried out due to the support of the Russian Science Foundation grant (project No.18-79-10168)

Application of the INR proton LINAC for development of methods of radiotherapy and nuclear medicine

The review of the results of researches in the field of proton therapy and contact radiotherapy (high-dose-rate brachytherapy) is presented. Medical beam formation elements for a wide range of proton energies were calculated, elaborated and tested with proton beams. These therapeutic beams cover most sizes and localizations of tumors. Researches of a new source for high-dose-rate brachytherapy with Yb-169 were carried out. This source has several important advantages compared to conventional sources. Experiments of activation of the new source at the INR Neutron complex were performed and therapeutic properties of the new source were confirmed. We also present in this paper the current status of the new target assembly for producing of some PET isotopes with 20 MeV protons.Проведено огляд результатів досліджень в області протонної терапії та контактної радіотерапії (високо-дозової брахітерапії). На підставі розрахунків були виготовлені і випробувані на протонному пучку елемен-ти системи формування базових терапевтичних пучків КПТ ІЯД РАН в широкому діапазоні енергій протонів. Ці пучки дозволяють проводити протонну терапію для новоутворень практично будь-якої локалізації. Були проведені дослідження нового джерела для високодозової брахітерапії на основі ізотопу Yb-169, що має ряд принципових переваг порівняно з іншими джерелами. Проводилися експерименти з активації нового джерела на нейтронному комплексі ІЯД РАН, які підтвердили його терапевтичні властивості. Показано стан справ зі збирання мішені для напрацювання ПЕТ ізотопів на пучку протонів з енергією 20 МеВ.Проведен обзор результатов исследований в области протонной терапии и контактной радиотерапии (высокодозовой брахитерапии). На основании расчетов были изготовлены и испытаны на протонном пучке элементы системы формирования базовых терапевтических пучков КПТ ИЯИ РАН в широком диапазоне энергий протонов. Эти пучки позволяют проводить протонную терапию для новообразований практически любой локализации. Были проведены исследования нового источника для высокодозовой брахитерапии на основе изотопа Yb-169, имеющего ряд принципиальных преимуществ по сравнению с другими источниками. Проводились эксперименты по активации нового источника на нейтронном комплексе ИЯИ РАН, подтвердившие его терапевтические свойства. Показано состояние дел по сборке мишени для наработки ПЭТ изотопов на пучке протонов с энергией 20 МэВ

Measurement Of The Σ̄- Lifetime And Direct Comparison With The Σ+ Lifetime

We have measured the lifetime of the Σ̄- using the Fermilab Proton Center 375 GeV/c charged hyperon beam. We obtained (80.43±0.80±0.14) ps. We also measured the lifetime of the Σ+, obtaining (80.38 ±0.40±0.14) ps, in agreement with the Particle Data Group value. A direct comparison between the two lifetimes from the ratio of the decay curves gives a fractional lifetime difference of Δτ/τ=(-0.06±1.12)%, consistent with equal lifetimes for baryon and antibaryon as required by CPT invariance. ©1999 The American Physical Society.61314Foucher, M., (1992) Phys. Rev. Lett., 68, p. 3004Timm, S., (1995) Phys. Rev. D, 51, p. 4638Dubbs, T., (1994) Phys. Rev. Lett., 72, p. 808Caso, C., (1998) Eur. Phys. J. C, 3, p. 690(1993) GEANT 3.21 CERN Program Library W5103, , CERNKuropatkin, N., private communicationLangland, J.L., (1995) Hyperon and Antihyperon Production in P-Cu Interactions, , Ph.D. thesis, University of IowaMorelos, A., (1993) Phys. Rev. Lett., 71, p. 341

Разработка модели биоимпедансометра

The model of a biomedansometer that generates a signal at a frequency of 20 Hz to 20 MHz is considered. The device consists of two units - the first unit is responsible for the generation of the signal, the second unit is responsible for reading and processing the data.В работе рассматривается модель биоимедансометра, генерирующего сигнал на частоте от 20 Гц до 20 МГц. Устройство состоит из двух блоков - первый блок отвечает за генерацию сигнала, второй блок отвечает за считывание и обработку полученных данных

Разработка модели биоимпедансометра

The model of a biomedansometer that generates a signal at a frequency of 20 Hz to 20 MHz is considered. The device consists of two units - the first unit is responsible for the generation of the signal, the second unit is responsible for reading and processing the data.В работе рассматривается модель биоимедансометра, генерирующего сигнал на частоте от 20 Гц до 20 МГц. Устройство состоит из двух блоков - первый блок отвечает за генерацию сигнала, второй блок отвечает за считывание и обработку полученных данных

NONLINEAR SPIN WAVES IN GRAPHENE STRUCTURES

Basing on Dirac equation for interacting massless fermions, we propose a nonlinear model that describes a possible mechanism of ferromagnetism in graphene structures, resulting from electron-electron interaction and spontaneous breaking of spin symmetry of valence electrons. Qualitative predictions of the model are important for practical applications in spintronics. Localized kink-antikink patterns of valence electron spin density on the graphene surface are calculated, their interaction is described, and, finally, the formation of their quasi-bound metastable states (breathers) is investigated. The spectrum of breathers is calculated in both the analytical and the numerical form. Possible inverted population of the appropriate states may be used to generate quantum coherent nonlinear spin waves that can find practical applications in nanoelectronics and spintronics