2015 12th International Symposium on Wireless Communication Systems (ISWCS). Brussels, Belgium, August 25-28, 2015. PROCEEDINGS
Due to the scarcity of license exempt spectrum at low frequencies, next generation multi-gigabit wireless communication will use 60 GHz. Propagation characteristics make impossible to use omnidirectional high-rate low-power transmission at long distances. As for directional transmission, it cannot be efficient with random channel access while the usage of deterministic one even in the state-of-the-art 60 GHz technologies - e.g. IEEE 802.11ad - raises a question of how much channel time shall be allocated for a stream to satisfy its QoS requirement. The main contribution of the paper is the mathematical model of Constant Bit Rate (CBR) flow transmission in IEEE 802.11ad networks, which allows to answer this question.
Network coding is a paradigm in data transport that allows a network node to code information flows before forwarding them. While it has been theoretically proven that network coding saves bandwidth and increases throughput of multicast communication, it does not directly consider the quality of service (QoS) requirements of multicast routing. In this paper, we study the problem of establishing minimum-cost, multiple multicast sessions over coded packet networks to meet the statistical QoS target considering boundedend-to-end statistical delay and jitter from source to each destination. For this purpose, we first propose a path-based formulation for the problem and prove that this problem is NP-hard. Then, in order to obtain an exact solution, we present an effective and efficient decomposition approach in which the problem is decomposed in to master problem and subproblems, and the solution is built up successively by feasible path generation.Computational results on random networks show that the proposed method provides an efficient way for solving the problem, even for relatively large networks.
We describe a new recommender system for the Russian interactive radio network FMhost. The underlying model combines collaborative and user-based approaches. The system extracts information from tags of listened tracks for matching user and radio station profiles and follows an adaptive online learning strategy based on user history. We also provide some basic examples and describe the quality of service evaluation methodology.
We describe a new recommender system for the Russian interactive radio network FMhost. The new recommender model combines collaborative and user-based approaches. The system extracts information from tags of listened tracks for matching user and radio station profiles and follows an adaptive online learning strategy based on user history. We also provide some basic examples and describe the quality of service evaluation methodology.
The results of numerical simulation of electrodynamic characteristics of a slow-wave structure shaped as a folded waveguide and an electron–optical system of a three-millimeter-band pulse travelling wave tube with an output pulsed power of up to 50 W are presented. The matching devices, the interaction space, and the electron–optical system are calculated, which allows determination of their constructive parameters. The effect of loss caused by the roughness of the surfaces of the walls of the electrodynamic system on the output characteristics of the device is estimated.
In this article comparative analysis of two methodologies of client satisfaction evaluation - CSI and NPS - is given. Based on this analysis it is proved that in case of tuning of NPS up to Russian specifics it better fits authors criteria for services industry. Necessity for testing of western NPS methodology before its mass use in practice of companies on Russian market is justified. Main results of adaptation of present methodology in Russia (with example of insurance industry) are given.
Generalized error-locating codes are discussed. An algorithm for calculation of the upper bound of the probability of erroneous decoding for known code parameters and the input error probability is given. Based on this algorithm, an algorithm for selection of the code parameters for a specified design and input and output error probabilities is constructed. The lower bound of the probability of erroneous decoding is given. Examples of the dependence of the probability of erroneous decoding on the input error probability are given and the behavior of the obtained curves is explained.
The dynamics of a two-component Davydov-Scott (DS) soliton with a small mismatch of the initial location or velocity of the high-frequency (HF) component was investigated within the framework of the Zakharov-type system of two coupled equations for the HF and low-frequency (LF) fields. In this system, the HF field is described by the linear Schrödinger equation with the potential generated by the LF component varying in time and space. The LF component in this system is described by the Korteweg-de Vries equation with a term of quadratic influence of the HF field on the LF field. The frequency of the DS soliton`s component oscillation was found analytically using the balance equation. The perturbed DS soliton was shown to be stable. The analytical results were confirmed by numerical simulations.
Radiation conditions are described for various space regions, radiation-induced effects in spacecraft materials and equipment components are considered and information on theoretical, computational, and experimental methods for studying radiation effects are presented. The peculiarities of radiation effects on nanostructures and some problems related to modeling and radiation testing of such structures are considered.