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81.
82.
An a posteriori (off-line) approach to the simultaneous detection and identification of quasi-periodic fragments in a numerical
sequence using their segments is analyzed. The solution of the problem is proposed for the case when the number of the desired
fragments is known. The following assumptions are made. (i) Each desired fragment of the numerical sequence coincides with
an element of the given alphabet of the reference sequences that have equal lengths (i.e., number of elements). (ii) Only
a segment (part) of the desired fragment can be processed; unprocessable parts of the fragment are interpreted as lost data.
(iii) The numbers of the elements in the sequence that correspond to the beginning of the desired fragment and the boundaries
of the segment in the fragment represent deterministic (rather than random) quantities; the boundaries of the segments are
different for different fragments; and the desired fragments are quasi-periodic in the sequence. (iv) Gaussian uncorrelated
noise impedes the observation of the sequence that contains quasi-periodic segments of the reference sequences. It is demonstrated
that the essence of the problem under study lies in the verification of a set of hypotheses on the mean value of a random
Gaussian vector (the power of this set exponentially increases with an increase in the dimension of the vector—the sequence
length). An effective a posteriori algorithm that provides for maximum-likelihood detection and identification is validated.
The estimates of the time and space complexity are related to the parameters of the problem. The results of the numerical
simulation are presented.
This work was supported by the Russian Foundation for Basic Research, project no. 03-01-00036 and 06-01-00058.
Aleksandr V. Kel’manov. Born April 25, 1952. Graduated from Izhevsk State Technical University in 1974. Received candidate’s degree in 1980 and
doctoral degree in 1994. Leading researcher of the Sobolev Institute of Mathematics, Siberian Division, Russian Academy of
Sciences. Scientific interests: mathematical methods for pattern recognition; discrete optimization; effective algorithms
for the analysis and recognition of random sequences; algorithms for the solution of applied problems; and methods and algorithms
for the processing, recognition, and synthesis of voice signals. Author of more than 120 papers.
Sergei A. Khamidullin. Born March 28, 1952. Graduated from Novosibirsk State University in 1974. Received candidate’s degree in 1997. Senior researcher
of the Sobolev Institute of Mathematics, Siberian Division, Russian Academy of Sciences. Scientific interests: mathematical
methods for pattern recognition; discrete optimization; effective algorithms for the analysis and recognition of random sequences;
algorithms for the solution of applied problems; and methods and algorithms for the processing, recognition, and synthesis
of voice signals. Author of more than 80 papers. 相似文献
83.
Mahmoud Abu-Zeid 《国际水资源开发杂志》2001,17(4):527-538
Access to water is viewed as a basic human right, a social necessity and a critical environmental resource in spite of the fact that water also has its own financial and economic values. Thus, the selection of set prices and pricing mechanisms addressing these contradicting views is remarkably complicated. On the other hand, water pricing is typically viewed as a good means to cover initial costs and sustain resources invested in water systems development, especially irrigated agriculture. Additionally, the cost of water services needs to be reasonable enough and linked to the amount of water consumed to encourage conservation. This paper illustrates criteria for equitable cost sharing, which include economic justification, efficiency and equity as well as users' acceptance. Elements of agricultural water pricing are also discussed. These elements comprise: the cost of water services, which is the total cost associated with irrigated agricultural systems development; the value of water, which reflects water's economic, social, environmental, cultural and religious values in the society; and the cost recovery mechanisms, which are the organizational and administrative measures to implement agreed upon policies to value water and services and make the collections. 相似文献
84.
S. O. Shiryaeva A. I. Grigor’ev V. A. Koromyslov A. S. Golovanov 《Technical Physics Letters》2002,28(1):41-43
A dispersion equation for the capillary oscillations of a charged drop of incompressible liquid possessing a finite electric
conductivity is derived with an allowance for the energy lost as a result of the electromagnetic wave emission. The magnitude
of the electromagnetic radiation losses of the oscillating drop linearly increases with the electric conductivity and the
surface mobility of charge carriers. 相似文献
85.
A. A. Lebedev A. M. Strel’chuk D. V. Davydov N. S. Savkina A. N. Kuznetsov L. M. Sorokin 《Technical Physics Letters》2002,28(9):792-794
The electrical characteristics of (p)3C-SiC-(n)6H-SiC epitaxial heterostructures obtained by sublimation epitaxy in vacuum are studied. The band discontinuities are determined and the energy band diagram of the heterojunction is constructed. It is shown that the obtained heterostructure offers a promising material for high electron mobility transistors. 相似文献
86.
Yu. P. Pyt’ev I. I. Falomkin A. I. Chulichkov 《Pattern Recognition and Image Analysis》2006,16(3):523-528
A new method for compression of grayscale images containing a small number of graphical elements is proposed. The method is
characterized by high compression ratios, small losses, and good readability of the processed images. It is based on morphological
methods of image analysis and could be used to store images of documents produced by fax machines, scanners, etc.
Igor I. Falomkin. Born 1979. Graduated from the Faculty of Physics, Moscow State University, in 2001. Scientific interests: image analysis
and recognition, analysis and interpretation of experimental data. 相似文献
87.
O. E. Stepanov A. V. Bulanov V. E. Karnaukhov M. L. Lukashenko Yu. B. Vorob’ev 《Thermal Engineering》2006,53(9):699-705
We consider two procedures for evaluating the influence of nondensables on steam condensation taking into account the integral effect from interaction between the water-chemistry and thermal-hydrodynamic processes occurring in the primary coolant circuit of a nuclear power installation (NPI). Results from calculations of the passive safety system of an NPI are given. 相似文献
88.
V. P. Il’ina 《Glass and Ceramics》2007,64(9-10):318-321
Facing and decorative glass crystal materials were developed from mineral feedstock and technogenic wastes. The effect of the components present in the mineral feedstock in liquation and crystallization of the glasses was investigated. The materials obtained can be used in construction for facing walls. 相似文献
89.
V. D. Belik R. V. Litvin M. S. Koval’chenko 《Powder Metallurgy and Metal Ceramics》2006,45(11-12):593-598
The influence exerted by electric-spark spraying on the kinetics of mass transfer and the physicomechanical properties of coatings is investigated. It is shown that electric-spark spraying is determined by the dynamic properties of the cathode jets, which depend on the electrical parameters of the spark discharge, the size of the interelectrode interval, and the physical properties of the coatings, which vary during spraying. 相似文献
90.
Golestaneh S. Hafez H.M. Mahmoud S.A. 《Vehicular Technology, IEEE Transactions on》1994,43(4):946-954
In FDMA cellular radio systems, the adjacent channel interference (ACI) is suppressed by the IF filter and also by a distance factor. Channels immediately adjacent to each other in frequency are assigned to different cells and, as such, the distance plays a role in reducing their mutual interference. The authors study the feasibility of optimizing the frequency spacing between carriers such that the combined effect of distance and IF filter will be enough to control the interference while allowing the maximum number of channels in a given bandwidth. They also study the decision feedback equalizer (DFE) as a means to reduce any excess ACI that results from reducing the channel spacing. The paper starts with a model that estimates the cumulative probability density of the signal to adjacent channel interference ratio (SIR) as a function of the channel spacing. They then present the results of a computer simulation study to estimate the performance of DFE in mitigating the effect of ACI. The results indicate that, under the conditions of slow flat fading and selection diversity, the DFE is very effective in reducing the effect of excess ACI interference which allows for a considerable reduction in the frequency spacing 相似文献