Damage buildup in Si under bombardment with MeV heavy atomic and molecular ions

Accumulation of structural disorder in Si bombarded at −196 °C with 0.5 MeV ²⁰⁹Bi₁ and 1 MeV ²⁰⁹Bi₂ ions (the so-called molecular effect) is studied by Rutherford backscattering/channeling spectrometry. Results show that the damage buildup is sigmodal even for such heavy-ion bombardment at liquid nitrogen temperature. This strongly suggests that, for the implant conditions of this study, the buildup of lattice damage cannot be considered as an accumulation of completely disordered regions. Instead, damage-dose curves are well described by a cascade-overlap model modified to take into account a catastrophic collapse of incompletely disordered regions into an amorphous phase after damage reaches some critical level. Results also show that Bi₂ ions produce more lattice damage than Bi₁ ions implanted to the same dose. The ratio of lattice disorder produced by Bi₂ and Bi₁ ions is 1.7 near the surface, decreases with depth, and finally becomes close to unity in the bulk defect peak region. Parameters of collision cascades obtained using ballistic calculations are in good agreement with experimental data. The molecular effect is attributed to a spatial overlap of (relatively dense) collision subcascades, which gives rise to (i) nonlinear energy spike processes and/or (ii) an increase in the defect clustering efficiency with an effective increase in the density of ion-beam-generated defects.Research at StPSTU was supported in part by the Ministry for General and Professional Education of the Russian Federation

Studies of the structure and functions of blood cells in senile patients with pneumonia on the biological model of hypoxia by scanning probe microscopy

Biological model of hypoxia can be used for the diagnosis of functional changes in human erythrocytes under the effect of the hypoxic factor. The use of this model together with modern methods of scanning probe microscopy for evaluation of the severity of pulmonological disease in senile patients will help to predict treatment efficiency and outcom

Instantaneous pitch estimation algorithm based on multirate sampling

The paper presents an algorithm for accurate pitch estimation that takes advantage of the sinusoidal model with instantaneous parameters. The algorithm decomposes the signal into subband components, extracts their instantaneous parameters and evaluates period candidate generating function (PCGF). In order to achieve high accuracy for low and high-pitched sounds it is assumed that possible pitch variation range is proportional to current pitch value. The bandwidths of the decomposition filters and length of the analysis frame are scaled for each period candidate by multirate sampling. The algorithm is compared to other widely used pitch extractors on artificial quasiperiodic signals and natural speech. The proposed algorithm shows a remarkable frequency and time resolution for pitch-modulated sounds and performs well both in clean and noisy conditions

КОНЦЕПЦІЯ МОБІЛЬНОЇ ЛАБОРАТОРІЇ КОМПЛЕКСНОЇ ОЦІНКИ ТА ПРОГНОЗУВАННЯ НАДЗВИЧАЙНИХ СИТУАЦІЙ

The concept of elaboration of mobile laboratories of integrated assessment and forecasting of emergency situations was developed. They provide operational radiation control in routine and emergency situations, remote and contact monitoring of concentration of harmful chemical contaminants in the atmosphere, soil, water, food, forage, etc. High technology equipment in theselaboratories enables to carry out assessment of the integral man-made and natural risks, to anticipate arising and development of emergency situations promptly, to forecast development and implementation of priority measures, to mitigate and eliminate potential effects of accidents and disasters.Розроблена концепція зі створення мобільних лабораторій комплексної оцінки та прогнозування надзвичайних ситуацій, які забезпечать оперативний радіаційний контроль в штатних і аварійних ситуаціях, дистанційний і контактний контроль концентрацій шкідливих хімічних домішок в атмосфері, ґрунті, воді, продуктах харчування, кормах та ін. Наукомістка апаратура таких лабораторій дає можливість проводити інтегральну оцінку техногенних і природних ризиків, прогнозувати виникнення та розвиток надзвичайних ситуацій, оперативно здійснювати розробку і впровадження першочергових заходів з ліквідації та пом'якшення можливих наслідків аварій і катастроф

ОБРАБОТКА РЕЧЕВЫХ СИГНАЛОВ В ПРИЛОЖЕНИЯХ МУЛЬТИМЕДИА НА ОСНОВЕ ПЕРИОДИЧЕСКОЙ МОДЕЛИ С НЕСТАЦИОНАРНЫМИ ПАРАМЕТРАМИ

Methods of time-varying speech parameterization for analysis, processing and synthesis in multimedia systems. The main theoretical points are given and practical issues are discussed. Some practical results of instantaneous pitch estimation and quality of voice morphing are presented.Рассматриваются методы нестационарной параметризации речевых сигналов, позволяющие выполнять анализ, обработку и синтез речи в приложениях мультимедиа. Формулируются основные теоретические положения и рассматриваются вопросы практической реализации. Приводятся результаты применения методов к задачам оценки основного тона и изменения просодических характеристик речевого сигнала

Modeling of innovation research clusters in the field of radioactive waste utilization

The situation with the processing and disposal of radioactive waste, including the liquid phase, is not resolved. Many questions remain regarding the environmental safety of processes and the technological implementation of the most energy-efficient solutions. Thus, the article’s main attention is paid to theoretical studies of the development innovation directions of radioactive waste processing using the VOSviewer software tool. The clusters were formed under modeling directions of application of radiolysis for radioactive waste utilization: the red cluster includes research of radionuclide sorption processes and their concentration for radiolysis of liquid media; the green cluster concerns factors of influence on water radiolysis in hydrogen production; the yellow cluster includes research areas of natural processes related to radiolysis; the blue cluster is connected with mathematical modeling of radiolysis process with fuel production and engineering implementation and the purple cluster related to the processes of radioactive waste management and disposal as well as the application of radiolysis for this purpose. The cluster simulations of nanoparticle and radiolysis applications for radioactive waste treatment have resulted in a new energy recovery strategy. The development of new matrix materials in combination with nanoparticles for the agglomeration and concentration of radionuclides is a promising innovation method improving radiolysis under hydrogen production from radioactive waste

ЦИФРОВЫЕ БАНКИ ФИЛЬТРОВ ДЛЯ СОВРЕМЕННЫХ ЗАДАЧ ОБРАБОТКИ ЗВУКОВЫХ СИГНАЛОВ

The paper reviews techniques of digital filter bank synthesis that can be applied for contemporary speech processing challenges. The paper describes practical experience of using digital filter banks in original systems of sound processing, namely, musical player with noise-aware audio enhancement and hearing aid application for a smartphone.В работе выполнен обзор способов синтеза цифровых банков фильтров, которые могут применяться для решения современных прикладных задач обработки звуковых сигналов. Описывается практический опыт использования цифровых банков фильтров в оригинальных системах обработки звука: музыкальном плеере с функцией повышения разборчивости звучания при прослушивании в шумной акустической обстановке, а также слуховом аппарате на базе смартфона

Voice Analysis and Classification System Based on Perturbation Parameters and Cepstral Presentation in Psychoacoustic Scales

Описан подход к построению системы анализа и классификации голосового сигнала на основе пертурбационных параметров и кепстрального представления. Рассмотрены два варианта кепстрального представления голосового сигнала: при помощи мел-частотных кепстральных коэффициентов (МЧКК) и при помощи барк-частотных кепстральных коэффициентов (БЧКК). В работе использовался общепринятый подход к вычислению МЧКК на основе частотно-временного анализа методом дискретного преобразования Фурье (ДПФ) с объединением энергии в субполосах. Данный метод аппроксимирует частотное разрешение слуха человека, но имеет фиксированное временное разрешение. В качестве альтернативы предложен вариант кепстрального представления на основе БЧКК. При расчете БЧКК использовался неравнополосный ДПФ-модулированный банк фильтров, аппроксимирующий частотную и временную разрешающую способность слуха. Целью работы ставилось сравнение эффективности применения признаков на основе МЧКК и БЧКК для построения систем анализа и классификации голосового сигнала. Результаты эксперимента показали, что в случае использования акустических признаков на основе МЧКК можно получить систему классификации голоса со средней полнотой классификации 80,6 %, а в случае использовании признаков на основе БЧКК этот показатель равен 83,7 %. При дополнении набора МЧКК признаков пертурбационными параметрами голоса средняя полнота классификации повысилась до 94,1 %, при аналогичном дополнении набора БЧКК признаков средняя полнота классификации увеличилась до 96,7 %. The paper describes an approach to design a system for analyzing and classification of a voice signal based on perturbation parameters and cepstral representation. Two variants of the cepstral representation of the voice signal are considered: based on mel-frequency cepstral coefficients (MFCC) and based on bark-frequency cepstral coefficients (BFCC). The work used a generally accepted approach to calculating the MFCC based on the time-frequency analysis by the method of discrete Fourier transform (DFT) with summation of energy in subbands. This method approximates the frequency resolution of human hearing, but has a fixed temporal resolution. As an alternative, a variant of the cepstral representation based on the BFCC has been proposed. When calculating the BFCC, a warped DFT-modulated filter bank was used, which approximates the frequency and temporal resolution of hearing. The aim of the work was to compare the effectiveness of the use of features based on the MFCC and BFCC for the designing systems for the analysis and classification of the voice signal. The results of the experiment showed that in the case when using acoustic features based on the MFCC, it is possible to obtain a voice classification system with an average recall of 80.6 %, and in the case when using features based on the BFCC, this metric is 83.7 %. With the addition of the set of MFCC features with perturbation parameters of the voice, the average recall of the classification increased to 94.1 %, with a similar addition to the set of BFCC features, the average recall of the classification increased up to 96.7 %

Система анализа и классификации голосового сигнала на основе пертрубационных параметров и кепстрального представления в психоакустических шкалах

The paper describes an approach to design a system for analyzing and classification of a voice signal based on perturbation parameters and cepstral representation. Two variants of the cepstral representation of the voice signal are considered: based on mel-frequency cepstral coefficients (MFCC) and based on bark-frequency cepstral coefficients (BFCC). The work used a generally accepted approach to calculating the MFCC based on the time-frequency analysis by the method of discrete Fourier transform (DFT) with summation of energy in subbands. This method approximates the frequency resolution of human hearing, but has a fixed temporal resolution. As an alternative, a variant of the cepstral representation based on the BFCC has been proposed. When calculating the BFCC, a warped DFT-modulated filter bank was used, which approximates the frequency and temporal resolution of hearing. The aim of the work was to compare the effectiveness of the use of features based on the MFCC and BFCC for the designing systems for the analysis and classification of the voice signal. The results of the experiment showed that in the case when using acoustic features based on the MFCC, it is possible to obtain a voice classification system with an average recall of 80.6 %, and in the case when using features based on the BFCC, this metric is 83.7 %. With the addition of the set of MFCC features with perturbation parameters of the voice, the average recall of the classification increased to 94.1 %, with a similar addition to the set of BFCC features, the average recall of the classification increased up to 96.7 %.Описан подход к построению системы анализа и классификации голосового сигнала на основе пертурбационных параметров и кепстрального представления. Рассмотрены два варианта кепстрального представления голосового сигнала: при помощи мел-частотных кепстральных коэффициентов (МЧКК) и при помощи барк-частотных кепстральных коэффициентов (БЧКК). В работе использовался общепринятый подход к вычислению МЧКК на основе частотно-временного анализа методом дискретного преобразования Фурье (ДПФ) с объединением энергии в субполосах. Данный метод аппроксимирует частотное разрешение слуха человека, но имеет фиксированное временное разрешение. В качестве альтернативы предложен вариант кепстрального представления на основе БЧКК. При расчете БЧКК использовался неравнополосный ДПФ-модулированный банк фильтров, аппроксимирующий частотную и временную разрешающую способность слуха. Целью работы ставилось сравнение эффективности применения признаков на основе МЧКК и БЧКК для построения систем анализа и классификации голосового сигнала. Результаты эксперимента показали, что в случае использования акустических признаков на основе МЧКК можно получить систему классификации голоса со средней полнотой классификации 80,6 %, а в случае использовании признаков на основе БЧКК этот показатель равен 83,7 %. При дополнении набора МЧКК признаков пертурбационными параметрами голоса средняя полнота классификации повысилась до 94,1 %, при аналогичном дополнении набора БЧКК признаков средняя полнота классификации увеличилась до 96,7 %

Optimal values of rovibronic energy levels for triplet electronic states of molecular deuterium

Optimal set of 1050 rovibronic energy levels for 35 triplet electronic states of $D_2$ has been obtained by means of a statistical analysis of all available wavenumbers of triplet-triplet rovibronic transitions studied in emission, absorption, laser and anticrossing spectroscopic experiments of various authors. We used a new method of the analysis (Lavrov, Ryazanov, JETP Letters, 2005), which does not need any \it a priory \rm assumptions concerning the molecular structure being based on only two fundamental principles: Rydberg-Ritz and maximum likelihood. The method provides the opportunity to obtain the RMS estimates for uncertainties of the experimental wavenumbers independent from those presented in original papers. 234 from 3822 published wavenumber values were found to be spurious, while the remaining set of the data may be divided into 20 subsets (samples) of uniformly precise data having close to normal distributions of random errors within the samples. New experimental wavenumber values of 125 questionable lines were obtained in the present work. Optimal values of the rovibronic levels were obtained from the experimental data set consisting of 3713 wavenumber values (3588 old and 125 new). The unknown shift between levels of ortho- and para- deuterium was found by least squares analysis of the $a^3\Sigma_g^+$, $v = 0$, $N = 0 \div 18$ rovibronic levels with odd and even values of $N$. All the energy levels were obtained relative to the lowest vibro-rotational level ($v = 0$, $N = 0$) of the $a^3\Sigma_g^+$ electronic state, and presented in tabular form together with the standard deviations of the empirical determination. New energy level values differ significantly from those available in literature.Comment: 46 pages, 9 picture