Influence of Intra-cell Traffic on the Output Power of Base Station in GSM

In this paper we analyze the influence of intracell traffic in a GSM cell on the base station output power. It is proved that intracell traffic increases this power. If offered traffic is small, the increase of output power is equal to the part of intracell traffic. When the offered traffic and, as the result, call loss increase, the increase of output power becomes less. The results of calculation are verified by the computer simulation of traffic process in the GSM cell. The calculation and the simulation consider the uniform distribution of mobile users in the cell, but the conclusions are of a general nature

Effective slip over superhydrophobic surfaces in thin channels

Superhydrophobic surfaces reduce drag by combining hydrophobicity and roughness to trap gas bubbles in a micro- and nanoscopic texture. Recent work has focused on specific cases, such as striped grooves or arrays of pillars, with limited theoretical guidance. Here, we consider the experimentally relevant limit of thin channels and obtain rigorous bounds on the effective slip length for any two-component (e.g. low-slip and high-slip) texture with given area fractions. Among all anisotropic textures, parallel stripes attain the largest (or smallest) possible slip in a straight, thin channel for parallel (or perpendicular) orientation with respect to the mean flow. For isotropic (e.g. chessboard or random) textures, the Hashin-Strikman conditions further constrain the effective slip. These results provide a framework for the rational design of superhydrophobic surfaces.Comment: 4+ page

Error Probability in Redundant Packet Sending over IP Network

In this paper we calculate error probability of packetized signal when method of redundant packet sending is used in IP network. The number of repeated signaling packets from each interval of packetization is determined to achieve the desired error probability. The method for management of this number of repetitions is developed based on the new analysis. This method is especially important in the case of sending signaling criteria of classic telephony network over IP network, because it makes possible to reach the same error probability as in classic telephony network

Direct interaction of pyridinium oximes with organophosphorus compounds

Ispitana je in vitro interakcija devet mono- i bis-piridinijskih mono- i dioksima sa tabunom, sarinom. somanom i VX. Reakcija je praćena spektrofotometrijski u pH 7,7 na 37 ºC pri koncentraciji oksima 5x10-5 mol/L i koncentraciji organofosfata 8x10-4 mol/L. Oksimi se najbrže fosforilišu tabunom i sarinom (t/2 = 3,4-16,7 min), nešto sporije somanom (·t/2 = 14.4-22.5 min), a veoma sporo ako se upotrebi VX (t/2 = 191,1-457,5 min). S obzirom na to da su konstante brzine izračunate na reakcije samo jedne koncentracije otrova i jedne koncentracije oksima, koje nisu identične koncentracijama u in vivo eksperimentu, teško je proceniti povezanost fosforilacije in vitro i efikasnosti oksima in vivo.A direct interaction of organophosphorus nerve agents sarin, tabun, soman and VX with nine quaternated pyridinium aldoximes was studied in vitro. The kinetics of the reaction (kobs) was measured by UV spectrophotometry from decrease in oxime concentration. At an oxime concentration of 5 x 10-5 mol/L and organophosphate concentration of 8 x 10-4 mol/L, at pH 7.7 the half-period of the reaction between oximes and sarin or tabun was between 3.4 and 16.7 min. The half-period of the reaction between oximes and soman was slightly increased (14.4-22.5 min), and between oximes and VX it was greatly increased (191.1-457.5 min). Considering that the reaction rate constants were calculated from the reaction of only one organophosphate and one oxime concentration, which were not identical with those in viva, it is difficult to estimate to what extent these reactions may be useful in the therapy of intoxication by nerve agents

Synthesis and Optimization of Reversible Circuits - A Survey

Reversible logic circuits have been historically motivated by theoretical research in low-power electronics as well as practical improvement of bit-manipulation transforms in cryptography and computer graphics. Recently, reversible circuits have attracted interest as components of quantum algorithms, as well as in photonic and nano-computing technologies where some switching devices offer no signal gain. Research in generating reversible logic distinguishes between circuit synthesis, post-synthesis optimization, and technology mapping. In this survey, we review algorithmic paradigms --- search-based, cycle-based, transformation-based, and BDD-based --- as well as specific algorithms for reversible synthesis, both exact and heuristic. We conclude the survey by outlining key open challenges in synthesis of reversible and quantum logic, as well as most common misconceptions.Comment: 34 pages, 15 figures, 2 table

Optical extinction, refractive index, and multiple scattering for suspensions of interacting colloidal particles

We provide a general microscopic theory of the scattering cross-section and of the refractive index for a system of interacting colloidal particles, exact at second order in the molecular polarizabilities. In particular: a) we show that the structural features of the suspension are encoded into the forward scattered field by multiple scattering effects, whose contribution is essential for the so-called "optical theorem" to hold in the presence of interactions; b) we investigate the role of radiation reaction on light extinction; c) we discuss our results in the framework of effective medium theories, presenting a general result for the effective refractive index valid, whatever the structural properties of the suspension, in the limit of particles much larger than the wavelength; d) by discussing strongly-interacting suspensions, we unravel subtle anomalous dispersion effects for the suspension refractive index.Comment: Submitted to Journal of Chemical Physics 37 pages, 4 figure

Determination of Base Station Emission Power Change in a Mobile Network Cell with Movable Users

This paper considers base transceiver station (BTS) emission power change in the cell-organized mobile network with dynamic power control, due to users’ moving. Such power adjustment contributes to energy saving and environment pollution reduction. We analyzed mutual influence of user’s moving speed, users’ surface distribution and propagation coefficient γ on BTS power variations. It is proved that users’ concentration near BTS, greater γ (in urban areas), faster user’s moving and greater connection duration contribute to BTS power increase of several tens of percent in real conditions. We present two examples when mean user’s moving distance is 30% of mobile cell radius: 1) power of one movable user is increased more than 50% when distance between user and BTS is uniformly distributed (decreasing users’ surface density); 2) emission power is decreased 2.5% when users are uniformly distributed (there are more users near a cell rim). BTS power has nearly constant value in the second example, because in our model users, crossing the cell rim, are replaced by users from adjacent cells, who are moving towards BTS. The analysis results are verified by Monte Carlo simulation, where user’s starting position, displacement and angle of moving are determined based on randomly generated numbers

Fatigue threshold as a parameter of hightemperature hydrogen degradation of low-alloy steels used for power and petrochemical equipment

In order to substantiate the choice of workability factor for the evaluation of mechanical state of metal, we have compared various mechanical factors by their sensitivity to hightemperature hydrogen degradation. Just local factors of fracture mechanics (such as fracture toughness and threshold Stress Intensity Factor) were found to be the most sensitive to such changes, and therefore subsequently Stress Intensity Factor was used as indicator of mechanical state of the metal with different degradation level. The inversion of effect of hydrogen, absorbed by degraded metal, on its effective threshold of cyclic crack resistance depending on number of thermocycles in hydrogen and exploitation time has been revealed. The metal state when negative effect of absorbed hydrogen on its effective threshold appears is suggested to be limiting