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The paper discusses new scheduling algorithms that are modifications of classical cycle based scheme, named the cycle based algorithm with time alternating priorities and time guard. The classical cycle based algorithm assumes that a given packet stream can be served only in predefined periods while it is not entitled to receive service in the periods dedicated to serve other packet streams. This...
Traditionally, the using an analog-to-digital conversion demands agreeing with the requirements of Shannon, Nyquist and Kotel'nikov theorem. According to this theorem, the frequency of the conversion should, at least, twice exceed the upper boundary frequency of the spectrum of the converted signal. It is also traditionally considered that the presence of high-frequency noises of more than one quantization...
Article deals with the problem of simulation modeling of robust control system for nonlinear plants with the input signal saturation, functioning under a priori uncertainty conditions and in the presence of several statement delays. With the help of computational experiments, the quality of the control system operation under various initial conditions of the controlled plant is illustrated.
The short reference differential chaos shift keying (SR-DCSK) is a variant of DCSK which increases data rata and enhances energy efficiency without extra complexity. However, the advantages of bit error ratio (BER) performance of the SR-DCSK over the conventional DCSK is not notable even if the optimal length of reference signal is applied. In this paper, we propose an improved SR-DCSK scheme where...
Delay Tolerant Networks (DTNs) differ from the traditional Mobile Ad Hoc networks (MANETs) in that DTNs are not always interconnected. The issue of routing data in a DTN is considered here. Many routing protocols exist for DTNs. Some are based on comparing nodes to each other, whereas others focus on the internal properties of the messages they hold. There are wide ranges of protocols, and they perform...
This paper investigates the deployment of an SDN-based UAV network providing communication service. Such a network is extremely useful in emergency scenarios. In such a network, the mobility of UAVs is minimal. We consider the placement of the SDN controller and its implications in terms of communication overhead and end-to-end delay of the control packets exchanged between the UAVs and the controller...
This paper investigates the network function virtualization (NFV)-enabled multicast problem, and proposes a steiner tree-based algorithm to reduce the cost of virtual network function (VNF) deployment and routing. In the algorithm, to minimize the bandwidth consumption, the Steiner tree is constructed by taking all the destination nodes as the terminals. Then a interconnection node of the tree is...
A new technique to reduce the clock jitter effect on single-bit continuous-time delta-sigma modulators (CTDSM) is proposed. It utilizes a delay line to generate N highly correlated clock sources to reconstruct the feedback waveform. Theoretical analysis show that the jitter-induced random noise power is reduced by a factor of 1/N2. Simulation results confirming the analysis are reported.
Supporting diverse services under a unified system is a major concern for the realization in the fifth generation (5G) cellular networks. In 5G systems, the massive connection property of massive machine-type communications (mMTC) results in the huge demand of physical downlink control channel (PDCCH) resources. Furthermore, greater overhead of PDCCH is indispensable for ultra-reliable downlink transmission...
This paper analyzes the transmission efficiency of two kinds of communication technologies: summation frame and individual frame. The abstract models for these two communication technologies using linear topology, which is the most popular topology in industrial control field, are proposed in this paper. The simulation results based on the models show that summation frame has a significant performance...
In Network Control Systems (NCSs), a dual rate controller is an approach that is applied to reduce the influence of packages loss and random delays. If the output measuring sensors is slower than the control action update can be reached, the dual rate controller is used as a possible solution. In this paper, a fuzzy controller will be combined with a dual rate controller in an NCS to regulate the...
The Hammerstein model is an effective way to model the nonlinear systems, which contains a nonlinear static block followed by a linear dynamic block. However, when facing with the strong nonlinear time-delay effects, the nonlinear memoryless block can not work very well. Hence, a time-delay neural network is used as a quasi-dynamic nonlinear block in the established nonlinear Hammerstein model which...
Simulation of the traffic flow is an effective approach to resolve the traffic congestion problem and expect to elucidate the traffic congestion mechanism. In this paper, we propose a traffic flow model based on the MLD (Mixed Logical Dynamical) system approach which regard the lane change and overtaking behavior. The research revealed that traffic jam spreads from driving lane to overtake lane.
There have been and there are still numerous initiatives aimed at improving the efficiency of Africa's trade corridors in order to make Africa more competitive in this modern and globalised world. If Africa is to fully participate in this emerging global phenomenon, the so called global value chains, then Africa has to immediately up her game in improving in all trade facilitating factors including...
Evolution of modern communications and radar systems have steadily increased the demand on modelling the propagation effects with real world scenarios for various signal types. The main purpose of this research is to create a flexible, generic and realistic Radio Frequency (RF) environment simulator including both radar and communication signals. Software defined radio (SDR) platform has been utilized...
Aiming at the issues of random delay and delay uncertainty in both the before channel and feedback channel for network control system, the root causes of random delay influence closed-loop control system by case is analysis, and the predictive control method based on neural network to solve the feasibility of existence network random delay in control system closed-loop control has provided. Simulation...
In this paper, we presented a graph-based computing model to perform the basic arithmetic operations using the DNA computing model with maximum parallelization capabilities. In other words, we proposed a mathematical transformation model to map the basic arithmetic operations to the Hamilton Path Problem (HPP) which can be solved with DNA computers easily and efficiently. Our analyses and simulations...
Mach-Zehnder Interferometer (MZI) is used to measure the phase shift (Δφ) between two light beams related to relative length difference (ΔL) of MZI's two arms. The phase shift of the interferometer output is represented by output Free Spectral Range (FSR). Thus the FSR can be configured by setting its length difference of the two arms, to vary the phase shift. In this paper, the FSR of two couplers...
When learning different control related concepts and methods, simulation is often used as a training tool; but, it does not have some real time characteristics of implementation like dealing with coding and PC resources, supervision, and communications. In some cases, implementation cannot be carried away, since it involves hardware design and is expensive. The proposed solution in this paper involves...
There are some shortcomings in the delay tolerant network (DTN) routing algorithm, such as low message delivery rate, low network efficiency and high cost in the satellite network. In order to solve the problem above, this paper proposes a limited copy algorithm MPWLC based on service probability. In MPWLC, not only is the number of copies limited, but the storage resources of the satellite are also...
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