Use of special-purpose bulk activity measures in monitoring raw materials and environmental objects

Mendeleev All-Union Metrology Research Institute. Translated from Atomnaya Énergiya, Vol. 73, No. 5, pp. 393–397, November 1992.     

A new approach for displaying identities and differences among aligned amino acid sequences.

An algorithm is presented for computing degrees of sequence conservation found among aligned amino acid sequences. Sequence identities are calculated for each position of an alignment and average identity values of neighboring positions are figured. The average identity value of the whole alignment is chosen as a limit to discriminate between well and less conserved sequence sections. A second algorithm is given to calculate the degree of divergence of individual sequences compared to the other sequences of the alignment. The approach is easy to use on microcomputers and gives an exact picture of sequence identities and differences in order to determine, first, protein regions of high functional or structural importance among homologous proteins, and, second, significant differences of single sequences that may contribute to individual properties of the analysed protein. The method is illustrated by an example analysing a sequence alignment of higher plant nitrate reductases.     

Ultrafast all-optical switching in GaAlAs integrated interferometer in 1.55 mu m spectral region

The first observation is reported of ultrafast all-optical switching in an integrated asymmetric Mach-Zehnder interferometer, using the nonresonant nonlinearity in Ga/sub 0.82/Al/sub 0.18/As below half the bandgap. A relative switching fraction of more than 80% has been achieved using 330 fs pulses at around 1.55 mu m from a coupled-cavity mode-locked colour centre laser.<>     

An air curtain for Protecting Hydraulic Structures from seismic and blast effects

Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 10, pp. 1–6, October, 1992.     

1-persistent carrier sense multiple access in radio channels withimperfect carrier sensing

A comprehensive analysis of a 1-persistent carrier-sense multi-access (CSMA) system using a radio channel with imperfect carrier sensing is presented and discussed. It is shown that a careful optimization of the channel state detector parameters must be performed in order to get good system performance. If the threshold of the detector is too high, the system will tend to behave like an unslotted ALOHA; if the threshold is too low, the system throughput will be zero. It is also shown that for the larger average packet rate G the system throughput is decreased. This is because for the same probability of correct channel sensing, the probability of incorrect transmissions from the waiting mode is increased     

Evaluation of the stressed-state of a bed based on emission memory effects of rocks in near-well space

Mining Institute, Moscow. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 2, pp. 26–29, March–April, 1991.     

Spectral predictions for pulse interval and width modulation

An expression for the frequency spectrum of pulse interval and width modulation (PIWM) is presented. Experimental results obtained have shown close agreement with spectral predictions from the formula. Performance figures are also included from a practical PIWM optical-fibre transmission system intended for use with TV and video signals.<>     

Sensitivity analysis of lossy coupled transmission lines

An analysis method, based on the numerical inversion of the Laplace transform, is described for the evaluation of the time domain sensitivity of networks that include lossy coupled transmission lines. The sensitivity can be calculated with respect to network components and parameters of the transmission lines. Sensitivity analysis is useful for waveform shaping and optimization. Examples and comparisons with sensitivity determined by perturbation are presented