Event-driven simulation of digital circuits using modified Petri nets algorithm

This paper presents a modified Petri nets simulation algorithm applied as an engine for a logic simulator in digital integrated circuit design. The simulator uses an event-driven algorithm and eliminates the delta delay which occurs in the majority of modern simulation algorithms. The algorithm has been tested for the logic simulation of combinational digital circuits and demonstrated more accurate simulation results. This has been achieved due to solving the issue of the priority choice problem when two or more events are occurring simultaneously

Thermodynamic aspects of materials' hardness: prediction of novel superhard high-pressure phases

In the present work we have proposed the method that allows one to easily estimate hardness and bulk modulus of known or hypothetical solid phases from the data on Gibbs energy of atomization of the elements and corresponding covalent radii. It has been shown that hardness and bulk moduli of compounds strongly correlate with their thermodynamic and structural properties. The proposed method may be used for a large number of compounds with various types of chemical bonding and structures; moreover, the temperature dependence of hardness may be calculated, that has been performed for diamond and cubic boron nitride. The correctness of this approach has been shown for the recently synthesized superhard diamond-like BC5. It has been predicted that the hypothetical forms of B2O3, diamond-like boron, BCx and COx, which could be synthesized at high pressures and temperatures, should have extreme hardness

Approaches of Russian oil companies to optimal capital structure

Oil companies play a vital role in Russian economy. Demand for hydrocarbon products will be increasing for the nearest decades simultaneously with the population growth and social needs. Change of raw-material orientation of Russian economy and the transition to the innovative way of the development do not exclude the development of oil industry in future. Moreover, society believes that this sector must bring the Russian economy on to the road of innovative development due to neo-industrialization. To achieve this, the government power as well as capital management of companies are required. To make their optimal capital structure, it is necessary to minimize the capital cost, decrease definite risks under existing limits, and maximize profitability. The capital structure analysis of Russian and foreign oil companies shows different approaches, reasons, as well as conditions and, consequently, equity capital and debt capital relationship and their cost, which demands the effective capital management strategy

Digital receivers for low-frequency radio telescopes UTR-2, URAN, GURT

This paper describes digital radio astronomical receivers used for decameter and meter wavelength observations. This paper describes digital radio astronomical receivers used for decameter and meter wavelength observations. Since 1998, digital receivers performing on-the-fly dynamic spectrum calculations or waveform data recording without data loss have been used at the UTR-2 radio telescope, the URAN VLBI system, and the GURT new generation radio telescope. Here we detail these receivers developed for operation in the strong interference environment that prevails in the decameter wavelength range. Data collected with these receivers allowed us to discover numerous radio astronomical objects and phenomena at low frequencies, a summary of which is also presented.Comment: 24 pages, 15 figure

Клинические особенности развития и прогрессирования первичной открытоугольной глаукомы у пациентов с отягощенным семейным анамнезом

PURPOSE. To identify clinical and epidemiological features of the course of primary open-angle glaucoma (POAG) in patients with a verified family history of the disease.METHODS. The study protocol included data from 103 people (103 eyes), among them 37 (35.9%) men and 66 (64.1%) women. Group 1 (44 people, 44 eyes) included patients with sporadic glaucoma. Group 2 consisted of patients with a hereditary form of the disease (41 people, 41 eyes). Healthy individuals (18 people, 18 eyes) comprised the control group. Mean age of all patients at the time of final examination was 60.6 (56.0; 66.3) years. In all cases, the diagnosis was established in accordance with the system of differential diagnosis of diseases. Examination was always carried out in person and included routine and specialized study methods (static automated perimetry, optical coherence tomography, examination of the thickness of the cornea in the central optical zone).RESULTS. The mean age of patients with a family history at the time of POAG diagnosis was 59.8 (53.9; 63.1) years, in patients with sporadic glaucoma — 63.85 (58.5; 67.9) years. Therefore, POAG in the group with a family history was diagnosed 4.05 years earlier. No significant differences in the structural and functional characteristics of the visual analyzer were established. A greater number of patients with the sporadic form of the disease undergo glaucoma surgery (47.7% and 34.1%, respectively) in comparable disease duration.CONCLUSION. In people with a family history of glaucoma, preventive screening should be carried out at an earlier age than the average in the population.ЦЕЛЬ. Определение клинико-эпидемиологических особенностей развития прогрессирования первичной открытоугольной глаукомы (ПОУГ) у пациентов с верифицированным семейным анамнезом.МЕТОДЫ. В протокол исследования были включены данные 103 человек (103 глаза), в числе которых было 37 (35,9%) мужчин и 66 (64,1%) женщин. В группу 1 (44 человека, 44 глаза) вошли пациенты со спорадической глаукомой. Пациенты с наследственно-отягощенной формой заболевания (41 человек, 41 глаз) составили группу 2.Здоровые лица (18 человек, 18 глаз) составили контрольную группу. Средний возраст всех пациентов на момент проведения финального обследования составил 60,6 (56,0; 66,3) лет. Во всех случаях диагноз был установлен в соответствии с системой дифференциальной диагн стики заболеваний. Обследование включало рутинные и специализированные методы исследования (статическая автоматизированная периметрия, оптическая когерентная томография, исследование толщины роговицы в центральной оптической зоне), и проводилось в очном формате.РЕЗУЛЬТАТЫ. Средний возраст пациентов с отягощенным семейным анамнезом на момент диагностирования ПОУГ составил 59,8 (53,9; 63,1) года, у пациентов со спорадической глаукомой — 63,85 (58,5; 67,9) года. Таким образом, ПОУГ в группе с наследственной отягощенностью была диагностирована на 4,05 года раньше. Достоверной разницы структурно-функциональных характеристик зрительного анализатора установлено не было. Большее число пациентов со спорадической формой заболевания оперируются по поводу заболевания (47,7% и 34,1% соответственно) на протяжении сопоставимого по срокам анамнеза заболевания.ЗАКЛЮЧЕНИЕ. Профилактические осмотры населения с целью выявления глаукомы у людей с наследственной отягощенностью по данному заболеванию, должны проводиться в более раннем возрасте, чем в среднем в популяции