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A5/1 and A5/2 are the GSM encryption algorithms that protect user data transmission over air. However, both of the A5/1 and A5/2 were cryptanalized by using different attack techniques such as time-memory trade off, divide and conquer and correlation attacks. In this study, we present a modified version of the A5/1 and A5/2 with offering security improvements to the vulnerabilities of the algorithms...
In this paper, we propose and solve the problem of feedback linearization of single-input control affine time-varying nonlinear systems. Feedback linearizability of time-varying is shown to be equivalent to the orbital feedback linearizability (or feedback linearization by state-dependent time scaling) of an extended version of the time-varying system. Necessary and sufficient conditions for feedback...
This paper describes the effects of input saturation in model-based fault diagnosis. A linear model has been used for the residual generator, in order to show its lack of robustness. The experiments have been developed on a simple simulation case: a liquid tank. The aim of the paper is to show the relation between the degree of nonlinearity and the performance of a diagnosis method based on linear...
In this paper, a nonlinear robust controller is proposed for the goal of power stabilization in power systems. The here-proposed approach is based on both the use of a properly-chosen sliding surface and the derivation of a disturbance attenuation condition (nonlinear L2-gain). The controller design is then applied to a single-machine-infinite-bus (SMIB) system and some simulation results demonstrate...
A smooth trajectory generator useful in motion control systems is presented. The considered generator is a second order nonlinear system which receives as input a standard reference signal (step, ramp, etc.) and provides as output a smooth reference signal satisfying proper nonlinear constraints on the state variables as, for example, bounds on the first time-derivative x of the output x, or bounds...
This paper is concerned with the ambiguity problem which is of major concern in a number of statistical signal processing applications. Initially, the concept of ‘hyperhelical’ parameterisation is presented and then a compact algorithm for the classification and calculation of ambiguities is proposed, in conjunction with two application areas: the array processing and the harmonic retrieval problem...
Aiming at the simulation for the prime mover supplied by thyristor, the principle and the fundamental methods to dynamically simulate the self-balancing characteristics of a turbine are studied in this paper. A new scheme is presented to simulate the characteristics of the prime mover when the generator simulator operates in various conditions. Nonlinear control components are adopted to solve long-existing...
Available Transfer Capability (ATC) of power system with large farms is influenced by many factors. These factors include wind farms output, load and generators output that they are uncertain and have statistical characteristics. This paper studies the feasibility and effectiveness of prediction ATC through Multivariable Linear Regression Models (MLRM). And the system which considering transmission...
In this paper, we are aimed to search the Pareto front of multi-objective optimal reactive power dispatch by the primal dual interior point method. In the front part are the introductions of optimal reactive power dispatch model, the concepts of Pareto optimum solution and Pareto front, and the primal dual interior point method. In the rear part, the process of searching Pareto front will be presented,...
This paper succeeds in solving the optimal reactive power dispatch (ORPD) of power system where the units contains wind turbines. Two types of wind turbine are taken into account in the ORPD, and they are the variable speed wind turbine (VSWT) and the fixed speed wind turbine (FSWT). Besides, the primal dual interior point method is introduced to serve as the algorithm to solve ORPD, since it performs...
This paper presents an analytical aggregation method for generator and its excitation system using structure preserving technique. It exactly considers the voltage deviations resulted from aggregating generators moved to the common bus. The parameters of the equivalent generator and its excitation systems are calculated directly in a non-iterative way. And in this paper, excitation systems of different...
Renewable energy developments have significantly influenced to the power system planning. In particular, in the last decade, renewable energy sources are considerably increased due to the supportive renewable energy policy worldwide. In this paper, an economic model is proposed to analyze the electricity market equilibrium under the impacts of renewable energy policy. In addition, the model reveals...
Aiming at the simulation for the prime mover supplied by thyristor, the principle and the fundamental methods to dynamically simulate the self-balancing characteristics of a turbine are studied in this paper. A new scheme is presented to simulate the characteristics of the prime mover when the generator simulator operates in various conditions. Nonlinear control components are adopted to solve long-existing...
In our day-today life, we performs a lot of tasks that involves direct or indirect use of random numbers e.g. Games, lotteries, simulations and most important cryptography and data communication security. Although, the field of pseudo random number generation is important, it is very difficult to find a good generator for several of applications. In present manuscript, we explore the possibility of...
This paper presents a temperature and supply compensated sub-threshold voltage reference generator which generates a reference voltage of 173 mV at supply voltage of 0.6 V and temperature @ 27 °C, has been designed in 45 nm CMOS technology. Variation of output voltage with temperature over a range of −25 to 85 °C is 172.88 to 173.25 mV which gives temperature coefficient of 19 ppm/°C at supply voltage...
This paper presents a configurable and optimized hardware architecture for computing Zadoff-Chu (ZC) complex sequences in the frequency domain. It is a hardware-efficient and accurate architecture for computing ZC sequences in realtime. The architecture is mainly based on the CORDIC algorithm for computing complex exponentials using only shift and add operations. Due to transformations applied to...
It is a general belief that voltage and current values are essential for calculating powers in circuit elements. We show that this belief is not justified in networks driven by power sources. We derive relation between injected powers and its constant fractions that are consumed in the circuit elements. Phasor (voltage and current) variables do not appear in this analytical expression. Injected power,...
The presence of distributed generators with DC output power and the advancement in power electronics devices have motivated system planners and grid operators to move towards integration of DC microgrids into conventional AC grid. In this paper, we address the optimal power flow (OPF) problem in AC-DC networks. The goal of the AC-DC OPF problem is to jointly minimize the total electricity generation...
An improved PID sliding mode control strategy with constant switching frequency for the voltage regulator of doubly salient electro-magnetic generator has been proposed in this paper. Next, operating principle of controller was described in detail and the stable condition of the system was deduced by Lyapunov function based on mathematical model and working principle of generator. Considering improved...
As the distributed generators are connected together through inverter interface in the microgrid, the control of the control of the interface inverter has an important influence on the operating performance of microgrid. In the paper, the study focuses on the control of the interfaced inverter, when microgrid operates in the islanded mode. In order to make the microgrid property similar to the utility...
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