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The queueing system with renewal arrival process, two types of customers, infinite number of servers and exponential service time is considered. Investigation of two-dimensional stochastic process that characterizes the number of busy devices for different types of customers is held by the method of initial moments.
The inspection (or renewal time) paradox is one of the basic results of the renewal theory. It expresses the mean stationary forward renewal time by means of the two first moments of the interrenewal time. We consider a single-server system with optical buffers and apply the inspection paradox to obtain more tight stability condition for the equidistant and asymptotically equidistant fiber delay lines...
In this paper, we develop a mathematical model of a load control mechanism for SIP server signaling networks based on a hysteretic technique. We investigate loss-based overload control, as proposed in recent IETF documents. The queuing model takes into account three types of system state — normal load, overload, and discard. The hysteretic control is made possible by introducing two thresholds, L...
The online collection of information about the consumption of gas, water, electricity and data from other sensors as temperature and humidity sensors or photo-voltaic systems became highly required. At the same time, the market liberalization on smart metering brought new challenges for utility distributors and telecommunication operators. Likewise, online data collection is crucial for increasing...
Methods for attitude & orbit control of the information satellites with economical expending of the energy and fuel onboard resources are presented. We consider the land-survey mini-satellites with an orbit altitude from 600 up to 800 km when their lifetime must be up to 10 years and economical control is actual problem.
This paper proposes a fuzzy interval type 2 logic based autonomous lateral flight controller for UAVs (unmanned aerial vehicles). The implementation framework utilizes MAT-LAB's standard configuration and the Aerosim Aeronautical Simulation Block Set which provides a complete set of tools for rapid development of detailed 6 degree-of-freedom nonlinear generic manned/unmanned aerial vehicle models...
In this paper we show the new approach to four-motors unmanned air vehicle control at the environment with rigid obstacles of various shapes. This approach is based on principles and methods of synergetic control theory. We explore analysis of mathematical model of four-motors unmanned air vehicle accounting of external disturbance action and synthesis of nonlinear synergetic control law for this...
Cognitive radio (CR) is seen as a promising technology to make radio spectrum usage more effective by providing an opportunistic access for secondary users to the licensed spectrum areas. CR systems need to detect the presence of a primary user (PU) signal by continuously sensing the spectrum area of interest. Radiowave propagation effects like fading and shadowing often complicate sensing of spectrum...
In this paper, we consider a cognitive radio (CR) link operating in a spectrum sharing (SS) mode with a primary network. In this mode, the primary and secondary users can share the same frequency band as long as the interference caused by the secondary network on the primary network is properly regulated. The optimal ergodic capacity of the secondary link that can be achieved is hence being investigated...
Iterative receiver combining multiple-input multiple-output (MIMO) detection with channel decoding is an attractive solution to greatly improve the error rate performance of wireless communication systems. However, such iterative process poses significant challenges for efficient receiver design. In this paper, a modification of soft-input soft-output K-Best decoder is proposed to provide high throughput...
The paper describes the modified backstopping robust algorithm for time-invariant linear single input single output (SISO) plants with delay. It is shown that the proposed algorithm is realized by one filter on input signal with dimension n, where n is a plant order. The derivatives of stabilizing control signals are not calculated but estimated by using the first order observer. This fact simplifies...
Capacity approximation of multi-hop unicast and multi-hop multicast channels is one of unsolved problems in information theory. Recently some researches investigate Degrees of Freedom (DoF) characterization and Interference Alignment schemes for these channels. However most of them assumed perfect instantaneous Channel State Information (CSI) at the relays and the transmitters. Due to practical limitations,...
Equipping vehicles with complicated information systems does not only introduce infotainment features but also makes it possible to implement new ideas to provide richer driving experience. The paper presents an approach integrating such concepts as smart space, collaborative recommendation system and context-based decision support. The key idea of the proposed approach is to implement context-based...
Nowadays simplified mathematical models and numerical simulation are widely used for the analysis of QPSK Costas loop. In the work it is shown that the use of simplified mathematical models and the application of non-rigorous methods of analysis may lead to wrong conclusions concerning the operability of real model of QPSK Costas loop.
In the paper the possibility of the vehicle speed estimation using the measurements of one sensor node which consist from the accelerometer and the magnetometer and located on the pavement is considered. The experiments on the test track demonstrated the good results: the speed estimation accuracy is approximately 90%. However, some improvements are needed before using the method on a regular road.
Recent achievements of automotive telematics in the area of communication channels integration for providing a persistent bidirectional link between vehicle and cloud infrastructure have intensified research in the field of mobile multiprotocol networks of intelligent vehicles oriented on cloud and fog environmental services. Synchronization of multiprotocol unit system clock is crucial for intelligent...
The paper deals with the robust algorithm for consensus control of dynamical networks where each local subsystem is described by nonlinear differential equation with delay, unknown parameters and disturbances. The algorithm provides the network synchronization and compensates uncontrollable disturbances with a given accuracy. Analytical results are presented by network consisting of four nodes.
In biology, the detection of visual motion is typically modeled via a set of elementary motion detectors (EMDs) forming a spatially distributed network. This paper summarizes recent results on estimating the dynamics of such an EMD construct from a biologically measured combination of their output signals. In particular, three interconnected problems pertaining to the field of system identification...
The problem of reasonable architectural and micro-architectural (at the level of functional blocks organization) synthesis still remains essential and the least formalized for complex embedded systems. Hardware and software components use configuration mechanisms at many system levels, which considerably complicates design. The HLD-methodology (High Level Design) of embedded systems design allows...
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