نشریه عصر برق
پیاپی 15 (تابستان 1400)

Quantum computing is a new method of information processing based on the concepts of quantum mechanics which leads to strange and powerful events in the field of quantum. Each unitary matrix represents a quantum gate. Synthesis of quantum circuits refers to the process of converting a quantum gate into a series of basic gates and is divided into two general categories, namely decomposition and composition-based. In the first category, quantum circuits are synthesized using matrix decomposition methods. This study deals with the second category, which uses evolutionary algorithms and especially genetic algorithms to multiply matrix gates to achieve the final characteristic of a quantum circuit.

In this paper, the overall structure of a digital camera is introduced and its most important part which is the CMOS image sensor, is explained in detail. After getting acquainted with the different parts of the image sensor, an image sensor has been designed using column-parallel architecture and a resolution of one megapixel. The most popular circuits have been used to design different blocks of the sensor. To evaluate image sensors, a variety of important sensor parameters with descriptions have been collected in the article.

Bifurcations are used in the biological, medicine and industry. In this article, first, the importance and applications of bifurcation and its types are discussed. Then, in particular, the hoop and bead system has been studied in both theoretical and laboratory forms, which have been determined by performing theoretical and practical experiments. In the laboratory discussion, a sensor for measuring angular velocity and a tool for reading the position of the bead were used to obtain a bifurcation diagram. As a result, the bifurcation diagram obtained from the experiment is important because it is an essential tool for studying system behavior change in response to changes in system parameters.

Due to the growing desire of people to join and use social networks, communication and shar ing data in these networks has been considered by various sciences such as political science, psychology, sociology, economics, etc. Hence, researchers have begun to distinguish and extract relationships between individuals from the data contained in these networks, to create more accurate communities. However, there is still no effective method to identify and extract communities based on social media data. In this article, a method has been proposed for social network accurate clustering by using Imperial Competitive Evolutionary Algorithm (ICEA) and selecting the initial population based on the density-based clustering criterion. The proposed method has improved the result of modularity about 21.45% in average, compared to rival basic ICEA and extracted more densed communities.

Due to the development of electricity market in a sustainable and competitive way in most countries, investigating the ability to transfer power has increased dramatically. Also, the increasing consumption and the lacking expansion of the transmission network have left most components of the power system within their authorized limits, which reduces the efficiency. Therefore, determining the exact amount of available transfer capability (ATC) is crucial for planning, operating and controlling the power system. There are many ways to calculate the ATC. The algorithms are either fast but not precise or accurate but not fast enough. This paper provides a comprehensive review of the various methods for determining ATC in both static and dynamic methods. First, the concepts and definitions essential to a better understanding of ATC are presented then in two separate parts the, static methods and dynamic methods are examined. These studies show that simultaneously with the development of static methods, dynamic methods have been also developed. This paper is useful both for those who already work in this field and also those willing to enter the field.

Sensor is a device that converts signals from one physical energy domain to electrical domain. Capacitive sensors have gain lots of attention because of their good performance, excellent sensitivity, easy-to-use principles, ease of manufacturing, etc. Due to the growing demand for the integrated on-chip electronic systems and need for the sensor downscaling, interdigital capacitor type of the sensors has become increasingly popular. These capacitors are the most common used capacitor structures in the micro electro- mechanical systems and are multi-finger periodic structures on an insulating substrate. Sensitivity and capacitance of the IDTs are relatively higher in comparison with the other capacitors that makes them to an attractive candidate in the sensor applications. This study reviews application of IDTs in the capacitive sensors.

It’s known that equalizing inductive reactance (caused by winding inductance) with capacitive reactance (caused by resonance capacitor) and creating resonant frequency is imperative to produce heat in metal pan located on induction cookers’ coil fed by classic resonant convertor. Moreover, the magnetic field induced by the currency passing through the induction cooker coil (with an active component and high frequency), produces Eddy currents in the pan and the Ohmic losses resulted from these currents (Req×I2 ) causes heat in the pan. Thus, in order to produce higher heat and cook faster, there is a need to increase the transitional active power to the cookers’ coils of these types and this in turn, raises the system efficiency. Increasing the transitional active power to the induction cookers’ coil means increasing the Ohmic losses caused by Eddy currents produced in the pan. To achieve this, by changing the circuit structure in classic resonant converter (using a voltage amplifying inductor in the converter input) as well as changing the switching system, a converter named “proposal converter” is developed and studied in this dissertation. This proposal converter increases the system efficiency by about 20 percent.

Recursive neural networks are a model of deep learning techniques that has been a very popular topic for the past few decades. LSTM neural networks are a new way of processing information that, because of its chain structure, operates on time-series data that leads to powerful deep learning events if LSTM is an important feature in the input sequence. Recognize in the early stages because of its short-term memory, it can transmit this information over long distances and receive and maintain such potential long-term dependencies. In this article, we have tried to examine the types of LSTM and their application in text processing in the fields of text classification, emotion analysis and feature extraction. In addition, we have also considered identifying future goals and highlighting the path of future research

The growing needs of communication, some of which are not even met by fifth-generation communication network technology, have led to research and targeting of the sixth generation communication network. According to various sources and references, it is predicted that by 2030, the capacity of the fifth generation communication network will reach its final level in today’s defined standards. Sixth Generation Communication Networks will be built primarily on the development of the fifth generation communication network architecture, and will inherit the benefits of the fifth generation communication network (for example, allowable frequency bandwidth and optimal decentralized network architecture). It is expected to update the communication technologies for the sixth generation of communication networks and to significantly improve the performance of telecommunication networks that we are familiar with today. With the goals set, the sixth generation communication network will have the characteristics of high bit rate, high reliability, low latency, high energy efficiency and high spectral efficiency.

Today, studies in plasmonic is mainly focused on integrating the Plasmonic Parts for optical communication and data transfer. Making such field resulted in studying new Plasmonic parts that developed in recent years. Some these parts are waveguides, couplers, optical modulators, optical detectors and optical sources. These circuit elements have an important position in the optical integrated circuits. Therefore, based on the main figure of Plasmonic devices which is the is able to go beyond the diffraction limits, design, simulation and construction of such elements have a special attractiveness for the researchers. In this research first, a Plasmonic laser has studied by using AlGaAs/GaAs/AlGaAs structure is the GaAs layer that itself interest environment quantum well that analyzed by using the metamaterial Plasmonic layser.