Showing 102 results for Ica
S. Abolmaali,
Volume 18, Issue 2 (6-2022)
Abstract
In this article, a critical path identification method is proposed for ternary logic circuits. The considered structure for the ternary circuits is based on 2:1 multiplexers. Sensitization conditions for the employed ternary multiplexers are introduced. Moreover, static timing analysis and dynamic programming are utilized in the identification of true and false paths of the circuit for obtaining more realistic results in a reasonable time. An event-driven simulation engine is also developed for confirming the sensitization state of the identified paths. Some ternary arithmetic logic circuits are designed to depict the effectiveness of the proposed identification method. Simulation results show the correctness and efficiency of the proposed method.
A. Jabbari,
Volume 18, Issue 2 (6-2022)
Abstract
Low-speed brushless permanent magnet machines are ideal for use in gearless propulsion systems. It is important to provide a precise analytical model to determine the performance characteristics of these machines. One of the challenges in designing permanent magnet machines is the elimination of the pulsating torque due to the presence of cogging torque and torque ripple components. The use of dummy slots (auxiliary teeth) is one of the most common methods of reducing pulsating torque phenomenon. In this paper, an accurate two-dimensional analytical model for calculating the magnetic vector potential in brushless permanent magnet machines is presented, taking into account the effect of stator slots, stator dummy slots, the magnetic direction of permanent magnets and phase winding style. The proposed analytical method is based on solving Laplace’s and Poisson’s equations using the separation of variables method for given regions in the subdomain approach. In the proposed method, to achieve a simpler analytical model, by changing the variable, the polar coordinate system is converted to a quasi-Cartesian coordinate system. Therefore, in mathematical terms, the hyperbolic functions are used instead of exponential ones. To validate the proposed model accuracy, the performance of a 14 kW low-speed brushless permanent magnet motor is calculated analytically and compared with the results of the numerical method and the experimental tests. Comparison of the performance results of this motor shows the consistency of analytical, numerical, and experimental results.
Gh. Khandar-Shahabad, J. Beiza, J. Pouladi, T. Abedinzadeh,
Volume 18, Issue 3 (9-2022)
Abstract
A new regionalization algorithm is presented to improve wide-area backup protection (WABP) of the power system. This method divides the power system into several protection zones based on the proposed optimal measurement device (MD) placement and electrical distances. The modified binary particle swarm optimization is used to achieve the optimal MD placement in the first step. Next, the power system is divided into small protection zones (SPZ) using the topology matrix of the power system and MD locations. Finally, the SPZs are combined to accomplish the main protection zones and protection centers according to electrical distances, degree of buses, and communication link constraints. The introduced regionalization formulation can help provide a rapid and secure WABP for power systems. This method was applied to several IEEE standard test systems, and the simulation results demonstrated the effectiveness of the proposed scheme.
M. Dodangeh, N. Ghaffarzadeh,
Volume 18, Issue 4 (12-2022)
Abstract
An intelligent strategy for the protection of AC microgrids is presented in this paper. This method was halving to an initial signal processing step and a machine learning-based forecasting step. The initial stage investigates currents and voltages with a window-based approach based on the dynamic decomposition method (DDM) and then involves the norms of the signals to the resultant DDM data. The results of the currents and voltages norms are applied as features for a topology data analysis algorithm for fault type classifying in the AC microgrid for fault location purposes. The Algorithm was tested on a microgrid that operates with precision equal to 100% in fault classification and a mean error lower than 20 m when forecasting the fault location. The proposed method robustly operates in sampling frequency, fault resistance variation, and noisy and high impedance fault conditions.
A. Rezapour, Z. Ahmadian,
Volume 19, Issue 1 (3-2023)
Abstract
Shamir’s secret sharing scheme is one of the substantial threshold primitives, based on which many security protocols are constructed such as group authentication schemes. Notwithstanding the unconditional security of Shamir's secret sharing scheme, protocols that are designed based on this scheme do not necessarily inherit this property. In this work, we evaluate the security of a lightweight group authentication scheme, introduced for IoT networks in IEEE IoT Journal in 2020, and prove its weakness against the linear subspace attack, which is a recently-proposed cryptanalytical method for secret sharing-based schemes. Then, we propose an efficient and attack-resistant group authentication protocol for IoT networks.
A. Aziznia, M. S. Akhavan Hejazi,
Volume 19, Issue 1 (3-2023)
Abstract
In this paper, a flexible pulsed power generator (FPPG) based on the solid-state Marx Structure is designed to create a wide range of pulses for cancer treatment. Pulse with different characteristics is needed to treat different samples depending on their type, dimensions, and impedance. Also, with the change in pulse widths, the pulse characteristics suitable for treatment change widely. With conventional semiconductor base Marx generators, due to the limitations in their rise time, current level, and impedance characteristics, it is not possible to generate a wide range of pulse characteristics, especially for low impedance loads. The FPPG by changing the connection mode of two Marx generators, can decrease the generator impedance for low impedance loads, increase the output current and voltage amplitude and repetition rate, and generate pulse width from nanosecond to several hundred microseconds. The simulation of FPPG in OrCAD-PSpice software shows its proper functioning.
H. Yaghobi,
Volume 19, Issue 2 (6-2023)
Abstract
For reliable operation, distance relays have to be blocked in case of stable power swings (SPSs). Because these relays are prone to detect an SPS as a symmetrical 3-phase fault according to their symmetric nature. It should be noted that there are zero and negative sequence components during asymmetrical faults. However, these components do not exist during stable fluctuations or symmetrical faults. Consequently, according to the symmetric nature of the stable fluctuation, the distance relay may experience maloperation. This article proposes a new technique to discriminate a symmetrical 3-phase fault from an SPS. The proposed technique is based on the extraction of the exponentially decaying DC component in the 3-phase current by using the MIMIC impedance. This technique can detect the symmetrical fault in less than a quarter of one power cycle. The suitability of the technique is shown by simulating various symmetrical faults during fast and slow SPS conditions.
Ananthakrishna T, Guru Prasad, A. Gopalkrishna Pai ,
Volume 19, Issue 3 (9-2023)
Abstract
This paper presents a low dropout voltage regulator, with the specifications suitable for hearing aid devices. The proposed LDO occupies very less area on chip and provides an excellent transient response. A novel voltage spike suppressor block is employed in the LDO architecture which reduces undershoot and overshoot of the output voltage during the abrupt load transition. It introduces a secondary negative feedback loop whose delay is lesser than the main loop and also steers the quiescent current to output node when required. This not only improves overall current efficiency but also reduces the on chip capacitance. The proposed LDO is laid out in 180 nm standard CMOS technology and post layout simulations are carried out. The LDO produces 0.9 V output when a minimum supply voltage of 1 V is applied. A maximum load of 0.5 mA can be driven by the regulator. The LDO exhibits 4.4 mV/V and 800 μV/mA line and load regulations respectively. When subjected to a step load change, an undershoot of 20.34 mV and an overshoot of 30.28 mV are recorded. For proper operation of the LDO, it requires only 4.5 pF on-chip capacitance.
A. Y. Abdulrahman, O. S. Zakariyya, A. S. Afolabi, A.t. Ajiboye,
Volume 19, Issue 3 (9-2023)
Abstract
Abstract: Rain attenuation prediction models are inevitably deployed to provide rough estimates of the actual measured attenuation due to severe scarcity in most of the tropical and equatorial climates. The results of rain attenuation measurements over a 14.8 GHz terrestrial microwave link and slant-path attenuation in vertically polarized signals propagating at 10.982 GHz in a tropical Malaysian climate were reported in this study. The experimental results including the path adjustment factors were compared with the predictions of some selected rain attenuation models. The relative errors in the path length adjustment factors (PLAFs) are in the range -0.3370 – 2.6272, while those of the slant path adjustment factors (SPAFs) are -0.9252 – +0.2923. Moreso, the charts of PLAFs and SPAFs at 0.01% of the time were also presented because they are the most commonly used availability by the telecommunications service providers. This study will allow the radio engineer to select the most suitable prediction models for the particular region under study, thereby ensuring adequate radio planning for improved service delivery especially in the tropical climates due to their peculiarity.
Ali Jabbari, Ali Badran,
Volume 19, Issue 3 (9-2023)
Abstract
Cost reduction, increased efficiency and reliability, extended service life, reduced noise and vibration, and environmental friendliness are critical for new generation wind turbines and electric vehicles. Segmented Hybrid Permanent Magnet (SHPM) machines, on the other hand, which are primarily segmented PMs combined with different materials, dimensions, and magnetization directions, offer a way to meet these needs. In this study, we present nine topologies of segmented PM-rotor SHPM generators based on the Taguchi experimental design method, while presenting a simple and accurate model based on subdomain method for estimating the magnetic performance characteristics of SHPM machines. An analytical model is provided. Magnetic partial differential equations (MPDEs) are represented in a pseudo-Cartesian coordinate system, and with appropriate boundary conditions (BC) and interface conditions (IC), the general solution and its Fourier coefficients are extracted using a variable separation approach. The performance characteristics of nine of the SHPM machines studied were compared semi-analytically and numerically. Two prototype SHPM machines were manufactured and semi-analytical modeling results were compared with finite element analysis (FEA) methods and experimental testing (load mode) on a generator. The FEA simulation and experimental test results have a maximum error rate of about 3, confirming the high accuracy of the provided semi-analytical model. We compare the induced voltage, torque ripple and magnetic torque among the investigated topologies.
S. Prasad Tiwari,
Volume 19, Issue 3 (9-2023)
Abstract
In spite of the numerous benefits over the traditional power distribution system, protection of the microgrid is a challenging and complex task. The varying fault resistances due to dissimilar grounding conditions can affect the performance of the protection scheme. Under such conditions, the magnitude of the fault current can vary from lower to higher level. In addition to the above, the dissimilar magnitude of fault current during grid connected and islanded mode demands a protection scheme that can easily discriminate the mode of operation. The magnitude of fault current in grid-connected and islanded modes needs a robust protection scheme. In this regard, an ensemble of subspace kNN based robust protection scheme has been proposed to detect the faulty conditions of the microgrid. The tasks of the mode detection, fault detection/classification as well as faulty line identification has been carried out in the proposed work. In the proposed protection scheme, discrete wavelet transform (DWT) has been used for processing of the data. After recording the voltage and current signals at bus-1, the protection scheme has been validated. The validation of the protection scheme in Section 6 reveals that the protection scheme is efficiently working.
Ayotunde Abimbola Ayorinde, Sulaiman Adeniyi Adekola, Ike Mowete,
Volume 19, Issue 4 (12-2023)
Abstract
This paper, using the circuit-geometric features of the Method of Moments (MoM), presents a comprehensive analytical treatment of an exponentially non-uniform helical antenna (ENH), mounted on a ground plane of finite extent. Earlier investigations reported in the literature established that the introduction of an exponential non-uniformity in the turns spacing of an otherwise uniformly wound helical antenna significantly improves its axial ratio and power gain profiles, but failed to address two important questions; one concerning the influence of the degree of non-uniformity on the antenna performance: and the other, the associated return loss profile, which is of particular importance in practical applications. It is shown in this paper, that when a properly designed impedance matching circuitry is introduced, a return loss of the ENH of close to 60 dB is achievable; without compromising axial ratio and gain performances. Indeed, axial ratio bandwidth remained unchanged at 54.55% for both the impedance-matched and unmatched ENHs, whilst maximum gain changed marginally from 14.19dB, for the unmatched ENH to 14.18dB for the impedance-matched antenna.
Maryam Akbari, Sattar Mirzakuchaki, Mahdi Fazeli, Mohammad Reza Tarihi,
Volume 19, Issue 4 (12-2023)
Abstract
In light of the growing prevalence of Internet of Things (IoT) devices, it has become essential to incorporate cryptographic protection techniques for high-security applications. Since IoT devices are resource-constraints in terms of power and area, finding cost-effective ways to enhance their security is necessary. Physical unclonable function (PUF) is considered a trusted hardware security mechanism that generates true and intrinsic randomness by extracting the inherent process variations of circuits. In this paper, a novel pure magnetic memory-based PUF is presented. The fundamental building blocks of the proposed PUF design are magnetic devices, the so-called mCells. These magnetoresistive devices exclusively utilize Magnetic Tunnel Junction (MTJ) components. Using purely MTJ in the main memory and sense amplifier in the proposed PUF leads to high randomness, high reliability, low power, and ultra-compact occupation area. The Monte Carlo HSPICE simulation results demonstrate that the proposed PUF achieves a uniqueness of 49.89%, uniformity of 50.02 %, power consumption of 1.43 µW, and an area occupation of 0.01 µm2 per bit.
Pardis Asghari, Alireza Zakariazadeh,
Volume 19, Issue 4 (12-2023)
Abstract
This paper proposes a novel approach to analyzing and managing electricity consumption using a clustering algorithm and a high-accuracy classifier for smart meter data. The proposed method utilizes a multilayer perceptron neural network classifier optimized by an Imperialist Competitive Algorithm (ICA) called ICA-optimized MLP, and a CD Index based on Fuzzy c-means to optimally determine representative load curves. A case study involving a real dataset of residential smart meters is conducted to validate the effectiveness of the proposed method, and the results demonstrate that the ICA-optimized MLP method achieves an accuracy of 98.62%, outperforming other classification methods. This approach has the potential to improve energy efficiency and reduce costs in the power system, making it a promising solution for analyzing and managing electricity consumption.
Ali Jabbari, Hassan Moradzadeh, Rasul Lotfi,
Volume 19, Issue 4 (12-2023)
Abstract
Along with the development of hybrid electric vehicles, researchers are trying to reduce existing limitations such as noise and environmental concerns and improve the efficiency and reliability of these systems. The use of magnetic gear technology is one of the solutions that have been recently proposed to remove these limitations and achieve higher benefits. In this paper, a mechanically coupled magnetic geared (MCMG) machine has been introduced. An accurate analytical model based on the subdomain method is presented to calculate the magnetic machine performance. To do this, first, a pseudo-Cartesian coordinate system is specified, and then the constitutive equations, i.e. Laplace’s and Poisson’s equations are rewritten for different regions of the machine. The separation of variables method was used to determine the general solution of the equations. Then by applying appropriate interface and boundary conditions, the Fourier coefficients of the equations were determined. To verify the analytical results, the performance of the proposed magnetic machine is numerically simulated using the finite element method in commercial software, and then a prototype is built and tested in three distinct modes. By comparing the analysis results with numerical simulation results and experimental tests, the high accuracy of the proposed analytical model can be confirmed.
Tasqiatul Qulbi Kamila Huda, I Gede Puja Astawa, Yoedy Moegiharto, Mohamad Ridwan, Budi Aswoyo, Anang Budikarso, Ida Anisah, Faridatun Nadziroh,
Volume 20, Issue 1 (3-2024)
Abstract
The progress of 5G networks is propelled by wireless technology, specifically mobile internet and smart devices. This article provides an in-depth analysis of the fundamental elements of 5G technology, encompassing the advancement of cellular networks, simultaneous transmission capabilities, energy efficiency enhancements, and the implementation of cooperative communication. This study examines the application of simultaneous wireless information and power transfer (SWIPT) in cooperative device-to-devices (D2D) communication. Specifically, it investigates relay selection using decode-forward (DF) protocols and considers the issue of self-interference. Radio frequency based energy harvesting (RF-EH) is proposed to address power limitations in device-to-device (D2D) communication. This article describes the development of this technology and suggests a system architecture that employs time-switching relaying (TSR) techniques to enhance the power efficiency of base stations. This research aims to assess data transfer efficiency in two-way cooperative communication systems by incorporating many technologies.
Ramin Safaeian, Mahmoud Tabandeh ,
Volume 20, Issue 2 (6-2024)
Abstract
Directed Acyclic Graphs stand as one of the prevailing approaches for representing causal relationships within a set of variables. With observational or interventional data, certain undirected edges within a causal DAG can be oriented. Performing intervention can be done in two different settings, passive and active. Here, we prove that an optimal intervention set can be obtained based on the minimum vertex cover of a graph. We propose an algorithm that efficiently identifies such an optimal intervention set for chordal graphs within polynomial time. Performing intervention on this optimal set recovers all the undirected edges in graph G, regardless of the underlying ground truth DAG. Furthermore, we present an algorithm for evaluating the performance of passive algorithms. This evaluation provides insights into how many intervention steps of a specific algorithm are required to recover all edges in the causal graph for any possible underlying ground truth in the equivalence class. Experimental findings underscore that the number of nodes in the optimal intervention set increases with growing the number of nodes in a graph, where the edge density is fixed, and also increases with the rising edge density in a graph with a fixed number of nodes.
Aws Alazawi, Huda Jameel, Mohammed Mohsen,
Volume 20, Issue 2 (6-2024)
Abstract
This study explores the use of distortion product otoacoustic emission (DPOAE) as a hearing screening modality for newborns and adults with hearing impairment. The goal is to improve cochlear response by developing digital filter characteristics to make it consistent for specialists to make accurate diagnoses. To accomplish this, the proposed system consists of a DPOAE ER-10C as stimulation and cochlear response probe, a digital signal processor, an oscilloscope, PC, and audio cables. Real-time distortion product frequency components were extracted using a signal processor of TMS320C6713. To validate the system, a senior medical physicist at Baghdad Medical City in Iraq conducted a study with five hearing-normal volunteers ages 38 and 55 at the center for hearing and communication. The results showed an ability to extract distortion product components in real-time implementation, with the superiority of shape parameters greater than 0.5. In addition, the quantization of filter coefficients was compared for both floating-point arithmetic and fixed-point arithmetic. Noisy environment-based noise reduction techniques have to be investigated by considering the implementation of robust digital signal processing techniques. Finally, the proposed system would contribute to advancements in hearing screening and treatment for those with hearing impairment.
Chhaya Belwal, Kunwar Singh, Shireesh Kumar Rai,
Volume 20, Issue 2 (6-2024)
Abstract
This paper introduces a floating flux-controlled meminductor emulator, implemented using two voltage differencing differential difference amplifier (VDDDA) along with a memristor and capacitor. Grounded and floating configurations are simulated with TSMC 0.18 µm level-49 BSIM3 CMOS process parameters in LTspice, showcasing the performance of the proposed circuits. The circuit features electronic tunability, allowing for the adjustment of nonlinear flux through the tuning of bias voltage. Simulation results validate the frequency-dependent current-flux dynamics of the proposed meminductor emulator. The simulation results, which involve frequency-dependent pinched hysteresis loops, transient analysis, non-volatility, and Monte Carlo analysis of the proposed meminductor, affirm the functionality and adequacy of the proposed design. A Chua’s oscillator is realized using proposed VDDDA-based meminductor as non-linear element.
Mohamad Almas Prakasa, Mohamad Idam Fuadi, Muhammad Ruswandi Djalal, Imam Robandi, Dimas Fajar Uman Putra,
Volume 20, Issue 3 (9-2024)
Abstract
The unbalanced load distribution in the electrical distribution network caused crucial power losses. This condition occurs in one of the electrical distribution networks, 20 kV Tarahan Substation, Province of Bandar Lampung, Indonesia. This condition can be maintained using optimal reconfiguration with the integration of Distributed Generation (DG) based on Renewable Energy (RE). This study demonstrates the optimal reconfiguration of the 20 kV Tarahan Substation with the integration of the Photovoltaic (PV) and Battery Energy Storage System (BESS). The reconfiguration process is optimized by using the Firefly Algorithm (FA). This process is conducted in the 24-hour simulation with various load profiles. The optimal reconfiguration is investigated in two scenarios based on without and with DG integration. The optimal configuration with more balanced load distribution conducted by FA reduces the power losses by up to 31.39% and 32.38% in without and with DG integration, respectively. Besides that, the DG integration improves the lowest voltage bus in the electrical distribution network from 0.95 p.u to 0.97 p.u.
