The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
A five-port Ka-band direct conversion receiver based on Six-port structures has been presented that is very suitable for software defined radio applications. An experimental prototype has been fabricated using microstrip components for 23-29 GHz frequency band. Simulation and measurement results are presented to validate the proposed approach. An exellent agreement shows the accuracy of the proposed...
In this study, two methods for solving economic dispatch problems, namely Hopfield neural network and lambda iteration method are compared. Three sample of power system with 3, 6 and 20 units have been considered. The time required for CPU, for solving economic dispatch of these two systems has been calculated. It has been shown that for on-line economic dispatch, Hopfield neural network is more efficient...
In this study, two methods for solving economic dispatch problems, namely Hopfield neural network and lambda iteration method are compared. Three sample of power system with 3, 6 and 20 units have been considered. The time required for CPU, for solving economic dispatch of these two systems has been calculated. It has been shown that for on-line economic dispatch, Hopfield neural network is more efficient...
In this paper, the Lyapunov function is used for nonlinear stability analysis of microwave oscillators. Using this method, both the instability of DC bias point and the stability of steady state oscillation can be analyzed. The successes of Lyapunov method, in nonlinear control theory, support the idea of using this method for stability analysis of microwave oscillators. In this paper the application...
A number of modulation strategies are used in multi-level power conversion applications. This paper is focused on novel multi-carrier PWM methods which have been extended for use in cascaded H-bridge multi-level inverter. Novel multi-carrier PWM method can be optimized or balanced the switch utilization in cascaded H-bridge multi-level inverter. Five-level cascaded H-bridge multi-level inverter has...
This paper provides an intelligence method for medium and long-term energy demand forecasting of a complicated electrical system. In this method we use energy data of several past years to train an adaptive network based on fuzzy inference system (ANFIS). We use this intelligence network to estimate the time series behaviour of energy consumption for several future years. Several simulations have...
Modal series is a new approach for modeling and analysis of nonlinear systems. This paper provides application of modal series to state estimation of nonlinear systems and introduces a new state estimation approach for nonlinear systems which uses a modal series model of nonlinear systems for Kalman filtering. The method implies a sequential use of Kalman filters which each one tries to decrease estimation...
The purpose of this study is to illustrate a new method for sensorless vector control of induction motors. This approach uses Zero-Crossing Times (ZCT) signal of stator current to estimate rotor speed. ZCT signal contains useful information which can be used for estimation of rotor speed and resistance. We have used this information for online estimation of rotor speed. To avoid time consuming fast...
In this paper we propose a traffic isolation method to be used in cluster-based broadcasting algorithms. For internal broadcast traffic, cluster-heads and gateways are responsible for re-broadcasting but for external ones, border nodes may perform the forwarding function as well. This simplifies the gateway selection method through the local selection of gateway nodes by its cluster head. This reduces...
In the regulated switching power supplies, the output voltage is usually sampled across a resistive voltage divider. In high voltage applications, the resistance of the voltage divider is very high in order to reduce its power loss. Therefore, these resistors are very good receivers of environment noise. This paper introduces a new control method for a high power, high voltage flyback converter insensitive...
A direct conversion modulator-demodulator with even harmonic mixers for fixed wireless applications is presented. The circuits consist of even harmonic mixers (EHMs) realized with antiparallel diode pairs (APDPs). The self-biased APDPs are used to flatten the conversion loss of the mixers. We also evaluate the different levels of I/Q imbalances and DC-offsets and use signal space concepts to analyze...
A cluster-based flooding algorithm for wireless ad hoc networks has been proposed. This mechanism uses a novel gateway usage approach. Dividing the flooding traffic to internal and external from each cluster point of view, gateway selection is just needed for the internal traffic. This simplifies the gateway selection method as well as improving the flooding performance parameters. The stability-based...
In this paper, we present a new direct conversion receiver based on multi-port structures that are very suitable for software defined radio applications. The proposed receiver is a five-port architecture which provides some advantages in compare to the previous architectures. The microwave simulations have been conducted to show its abilities as a direct demodulator. Meanwhile, the measured results...
In this paper, an analytical approach is proposed to study the performance of HBT_HEMT matrix amplifiers. A closed form relation for the central line attenuation function of the matrix amplifier is obtained which is very useful in the consideration of the influence of several parameters on the device performance. It is shown that this structure may have lower attenuation respect to the traditional...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.