.

No abstract

Дискретная математика том 13 ВЫПУСК 4 * 2001 УДК 519.7 О свойствах функций, представимых в виде 2-КНФ © 2001 г. А. В. Тарасов В статье рассматриваются свойства булевых биюнктивных функций. Класс булевых биюнктивных функций состоит из функций, представимых в виде 2-КНФ. В работе построен алгоритм минимизации биюнктивных функций, ис следуются некоторые свойства этих функций.

No abstract

Background and Purpose-Population-based data on transient ischemic attack (TIA) incidence are scarce. This study defines incidence rates of first-ever TIA in Novosibirsk, Russia, during 1987Russia, during -1997 and compares the incidence of first TIA with that of first stroke. Methods-This is a prospective registry population-based study of all new cases of TIA and stroke in an overall population of 455 765 residents of Novosibirsk. All new TIA and stroke incident cases (whether inpatient or outpatient) that occurred during 1987-1988 and 1996 -1997 study periods were recorded and analyzed. A 95% CI was estimated for all age-and sex-specific strata. Results-During the 2 study periods, a total of 211 patients with first TIA were registered in the population studied. The crude annual TIA incidence rate per 100 000 residents was 16 (95% CI, 8 to 33) in -1988 and 29 (95% CI, 9 to 87) in 1996 -1997; these rates standardized to the European population were 17 (95% CI, 8 to 34) and 27 (95% CI, 9 to 79), respectively. Eighty-three percent of TIAs occurred in the carotid arteries (rate, 48/100 000), 10% occurred in the vertebrobasilar territory (rate, 6/100 000), and 7% of cases had a TIA of uncertain distribution (rate, 2/100 000). Conclusions-Unlike stroke incidence rate, the incidence rate of TIA in Novosibirsk is similar to that in other populationsand constitutes approximately 10% of stroke incidence. For the last decade (1987)(1988)(1989)(1990)(1991)(1992)(1993)(1994)(1995)(1996)(1997), there was a tendency, although statistically insignificant, toward increasing incidence rate of TIA in the population studied. (Stroke. 2000;31:9-13.) Key Words: epidemiology Ⅲ incidence Ⅲ stroke Ⅲ transient ischemic attack P opulation-based data on transient ischemic attack (TIA) incidence are scarce. Although incidence of TIA has been reported for numerous sites worldwide, only few incident population-based studies on TIA in all age groups of the population have been reported thus far. [1][2][3][4][5][6][7][8][9][10][11] No such data in Russia have ever been published in the international literature. However, data on TIA incidence trends are important in determining mechanisms and factors responsible for the occurrence of this disorder. Thus far only 2 truly populationbased studies 2,4 have addressed a relationship between TIA and stroke incidence rates over a period of 1 or a few decades. Herein we summarize the TIA incidence rates in Novosibirsk, Russia, for the last 10 years, from 1987-1988 to 1996 -1997, and we compare the incidence of first TIA with that of first stroke obtained in the same study population and during the same study periods. Subjects and MethodsThis prospective registry population-based study was conducted during 1987-1988 and 1996 -1997 in the general, unselected, and representative districts of Novosibirsk, Oktyabrsky District and Leninsky District. The population at risk, as determined by all-union census estimates in 1989, was 155 091 residents (85 028 women and 70 063 men) in Oktyabrsky District and...

Tc metal and metal-like carbide phases are revisited with special attention given to Tc-rich phases in the view of prospective nuclear fuel utilization and alternative transmutation targets fabrication. A new Tc-metal phase has been found and new softer conditions for the Tc carbide formation were observed. The unit cell parameters of a new orthorhombic Tc metal were a = 2.805(4), b = 4.958(8), c = 4.474(5)•ð (V/z = 15.55 •ð) for Tc-C with 1.38 wt.% C and a = 2.815(4), b = 4.963(8), c = 4.482(5) •ð (V/z = 15.65 A) for Tc-C with 1.96 wt.% C.

No abstract

В статье рассматриваются булевы функции от n переменных, не имеющие имплицент от k, 1 ⩽ k < n, переменных. Получены оценки минимально возможного веса w (n, k) таких функций. Показано, что w (n, 1) = 2, n = 2, 3, ..., и w (n, 2) ∼ log 2 n при n → ∞, а для k > 2 существует такое n0, что w (n, k) > 2 k−2 • log 2 n при всех n > n0.