Asymptotic solution of the optimal speed problem for the quasilinear system under Euclidean constraint on control

For the system with a small parameter under nonlinearities, consideration was given to the problem of optimal speed. The values of the multivariable control actions are bounded in the Euclidean norm. The theorem of existence and asymptotic properties of the solution of this problem was proved. It underlies the algorithm to construct asymptotic arbitrary-order approximations to the optimal control.     

VBÉR-300 reactor system and power-generating units for regional nuclear power production

The basic design solutions and characteristics of the VBéR-300 reactor system for the power-generating units of 150–300 MW(e) nuclear power plants and regional nuclear heat-and-electricity plants are described. The reactor system implemented as a unit is based on the technologies and solutions used for marine nuclear power systems, which have been corroborated by experience in operating nuclear-powered icebreakers. The technical-economic advantages of floating power-generating units are substantiated. __________ Translated from Atomnaya énergiya, Vol. 102, No. 1, pp. 35–39, January, 2007.     

A theory of personalisation of appearance: quantitative evaluation of qualitatively derived data

Using qualitative data, Blom and Monk (2003) derived a theory of why people choose to personalise the appearance of their PCs and mobile phones. This paper describes some quantitative data that provide some support for, and some modifications to, the theory. Individuals having personal home pages were recruited to fill in a questionnaire that assesses dispositions to personalise and its effects. In addition the 82 home pages were inspected to assess the extent of personalisation. This correlated significantly with the dispositions 'Frequency of Use' and 'Knowledge of Personalisation'. The questionnaire items corresponding to effects were factor analysed. A four-factor solution suggested item groupings similar, but not identical, to those used in the theory. There are significant positive correlations between the extent of personalisation and cognitive effects and enduring emotional effects. The value of quantitative data for confirming and refining a qualitative theory is discussed.     

Use of waterless molding mixtures as a substitute for the traditional sandy-argillaceous mixtures

In the last years, there is carried out an intensive search for new molding mixtures capable of replacing sand-argillaceous mixtures whose properties have already been well studied. Unfortunately, the majority of them form a mold in the course of the hardening of a bonding agent, which requires creating a complex system for the regeneration of the used sand. In this connection, we investigated a waterless molding mixture with the use of organobentonite as the binder, which does not require any changes in the technological process of green-sand molding. The influence of the amount and composition of the solvent on the properties of waterless mixtures is estimated.     

非洲妇女面临的困境

事实上所有非洲国家都存在着一个非常重要的现象，那就是在国家独立之后由于原先禁止妇女移民进入城市的法律法规有所松动，不断有大量的妇女人VI正迁移向城市。     

Scaling Laws for One- and Two-Dimensional Random Wireless Networks in the Low-Attenuation Regime

The capacity scaling of extended two-dimensional wireless networks is known in the high-attenuation regime, i.e., when the power path loss exponent alpha is greater than 4. This has been accomplished by deriving information-theoretic upper bounds for this regime that match the corresponding lower bounds. On the contrary, not much is known in the so-called low-attenuation regime when 2lesalphales4. (For one-dimensional networks, the uncharacterized regime is 1lesalphales2.5.) The dichotomy is due to the fact that while communication is highly power-limited in the first case and power-based arguments suffice to get tight upper bounds, the study of the low-attenuation regime requires a more precise analysis of the degrees of freedom involved. In this paper, we study the capacity scaling of extended wireless networks with an emphasis on the low-attenuation regime and show that in the absence of small scale fading, the low attenuation regime does not behave significantly different from the high attenuation regime.     

Empirical analysis of a 2 x 2 MIMO channel in outdoor-indoor scenarios for BFWA applications

The unquestionable advantages of multiple-input multiple-output (MIMO) systems are having a strong influence on the development of new wireless systems, both in wireless local-area networks (WLANs), and in those designed to offer broadband fixed wireless access (BFWA) services in wireless metropolitan-area networks (WMANs). The MIMO channel characterization in different environments and for different operating frequency bands is a crucial factor in the design of new systems and standards, and for adequate planning of existing systems. This article makes two main contributions. First, the experimental characterization of a 2 times 2 MIMO channel at a frequency of 2.4 GHz in a canonical outdoor-indoor scenario is presented. The channel characterization performed includes the analysis of the spatial correlation between the MIMO system subchannels and its impact on the channel capacity. Second, on the basis of the capacity results obtained, a proposal is made for the use of a 2 times 2 MIMO system in outdoor-indoor scenarios for BFWA applications in metropolitan environments. The proposal is based on the experimentally verified hypothesis that the path loss due to building penetration can be practically compensated for by the diversity gain of 2 times 2 systems     

Effect of stationary ionization of traps near the midgap on the spectrum of thermally stimulated capacitance of semiconductor devices

An algorithm for calculating the parameters of deep-level centers in the space-charge region of semiconductor devices on the basis of an analysis of the curves of thermally stimulated capacitance in the presence of recombination centers with the levels located near the midgap is suggested. The method is tested using the commercial AL-107 GaAs-based light-emitting diodes. The results of calculations of the deep-center parameters in the materials under study are consistent with the results of other methods of analysis.     

Metabolic factors have a major impact on kidney allograft survival

BACKGROUND: At the present time, late graft loss is the major cause of kidney failure after transplantation. However, the influence of metabolic factors on this process is ill-defined. METHODS: To identify the impact of lipid metabolism, glucose metabolism, and blood pressure and their prognostic value for graft survival, data for all recipients of a kidney allograft with a potential graft survival of >15 years and a minimum graft survival of 1 month were analyzed retrospectively. Recipients of kidney grafts functioning more than 15 years (n=32) were compared with those with a graft function of less than 10 years (n=152, controls) and evaluated in a multivariate analysis. RESULTS: Low levels of serum cholesterol, triglycerides, and glucose, before and after transplantation, were accompanied by a prolonged graft survival. Prognostic factors for early graft failure included serum triglycerides >300 mg/dl, cholesterol >250 mg/dl before transplantation, serum creatinine >4.0 mg/dl 1 month after transplantation, and donor age above 45 or less than 10 years. Additionally, systolic and, particularly, diastolic blood pressure was lower in the group with a prolonged graft function as compared with controls immediately before and after transplantation. In addition, the incidence of primary graft function was lower and the incidence of acute rejection episodes higher in controls. Cold and warm ischemic time, body mass index, recipient age, and gender did not differ significantly. CONCLUSIONS: Our data suggest that metabolic parameters play an important role in the process of late graft loss after kidney transplantation.     

A characterization of permolybdate and its effect on cellular tyrosine phosphorylation, gap junctional intercellular communication and phosphorylation status of the gap junction protein, connexin43

Biological and analytical characterizations of permolybdate (a mixture of H2O2 and molybdate) were done. Molybdate (10 mM) and molybdenum(V) chloride (3 mM) did not affect gap junctional intercellular communication (GJIC), phosphorylation status of connexin43 (Cx43) or cellular tyrosine phosphorylation in early passage hamster embryonic cells (mainly fibroblast-like). High concentrations of H2O2 (3-10 mM) affected some of the parameters. Acidified permolybdate was clearly more stable than the unadjusted permolybdate. The maximum biological potency of acidified permolybdate was found at a molar ratio of 2:1 (H2O2:molybdate). The mixtures of molybdenum(V) chloride and H2O2 gave a maximum effect at 4:1 molar ratio (H2O2:molybdenum(V)). This can be explained by decomposition of H2O2 and by the generation of less biologically active compounds. Spectrophotometric analyses of the mixtures corroborated the biological results. The Mo(V) electron spin resonance spectrum disappeared upon addition of H2O2 to Mo(V) solutions, and no spectrum appeared when H2O2 was mixed with Mo(VI). Thus, permolybdate is probably diperoxomolybdate, a Mo(VI) compound. Regardless of the parent metal salt, the H2O2/metal salt mixtures showed concentration-dependent biphasic responses with an initial decrease in GJIC followed by an increase. A dissociation between alteration in Cx43 phosphorylation status and GJIC was obtained under certain conditions. The biological activities of permolybdate were only partially mimicked by phenylarsine oxide, an alternative protein tyrosine phosphatase inhibitor.