Communication
Mehdi Rezaei; Arshnoos Nakhaei; Yaser Rahimi; Pouria Jafari
Abstract
This paper proposes a novel Optimal Deep Rate Controller (ODRC) designed for intra-coding configuration of the High-Efficiency Video Coding standard. The ODRC incorporates a Convolutional Neural Network-based Rate-Quantization Model (CRQM) to effectively predict bit consumption across the entire Quantization ...
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This paper proposes a novel Optimal Deep Rate Controller (ODRC) designed for intra-coding configuration of the High-Efficiency Video Coding standard. The ODRC incorporates a Convolutional Neural Network-based Rate-Quantization Model (CRQM) to effectively predict bit consumption across the entire Quantization Parameter (QP) range at the Coding Tree Unit (CTU) level. The proposed rate controller employs an optimization algorithm to minimize the buffering delay required for video communications. By establishing a specific search space through the CRQM, a greedy search algorithm is utilized to determine the optimal frame-level QP, thereby minimizing discrepancies between buffer occupancy and target occupancy. Unlike CTU-level rate controllers, which can introduce quality variations due to QP fluctuations among CTUs, the frame-level ODRC maintains consistent objective quality across CTUs within a frame. The ODRC is integrated within the standard reference software HM-16.20. Comparative evaluations with the default rate controller, RC-HM, in the same software, demonstrate the superior performance of ODRC in terms of both delay and bit error ratio. Experimental results indicate that ODRC achieves a notably lower average buffering delay of 0.02s and a lower bit error ratio of 11.25%, in contrast to RC-HM's 0.3s and 44.72%, respectively, emphasizing its effectiveness for HEVC low-delay applications.
Communication
Khalil Jahani; Behzad Moshiri; Babak Hossein Khalaj
Abstract
With the proliferation of federated learning programs as a suitable framework for protecting user privacy and reducing the computational overhead of AI algorithms, various industries have also turned to the widespread use of this framework in industrial applications such as improving predictive maintenance ...
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With the proliferation of federated learning programs as a suitable framework for protecting user privacy and reducing the computational overhead of AI algorithms, various industries have also turned to the widespread use of this framework in industrial applications such as improving predictive maintenance (PDM). However, despite its increasing applications, several security challenges, such as Byzantine attacks, make the application of federated learning in industries questionable. Byzantine attacks in FL can degrade model performance by injecting malicious updates, causing model divergence or biased learning. This reduces accuracy, and can introduce security vulnerabilities such as backdoors. To address this problem, we propose a Byzantine Fault Tolerant (BFT) federated learning algorithm designed to improve PDM in industrial applications. Our proposed approach uses a PCA-based anomaly detection algorithm to detect and mitigate local Byzantine updates. Also, a game theory-based reward mechanism is designed to promote honest participation and discourage malicious behavior among federated users. The proposed framework is evaluated using the predictive maintenance datasets “AI4I 2020” and “NASA Acoustics and Vibration”. The results show that our proposed framework effectively detects and mitigates Byzantine attacks, enhancing the overall reliability of PDM in industrial applications.
Communication
Motahareh Arezoomandan; Shahram Mohanna; Ahmad Bakhtiyari Shahri
Abstract
A new compact Ultra-Wide Band (UWB) arch shaped wide-slot antenna has been implemented for Microwave Imaging (MI) of breast cancer. It includes a fork-shaped strip and an arched slot ground, has a compact size of 16×20mm with a height of 1mm. The arched slot in the ground plate enhances the impedance ...
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A new compact Ultra-Wide Band (UWB) arch shaped wide-slot antenna has been implemented for Microwave Imaging (MI) of breast cancer. It includes a fork-shaped strip and an arched slot ground, has a compact size of 16×20mm with a height of 1mm. The arched slot in the ground plate enhances the impedance bandwidth and the gain of the antenna. It has a bandwidth of 3.7 GHz to 18 GHz, that covers WLAN (5.4 GHz), X band (8-12 GHz), and Ku band (12-18 GHz) and having gain of 2.7 dBi to 6.3 dBi in the frequency ranges. The fidelity factor was computed for both E-plane and H-plane scenarios, indicating range of 0.922 to 0.975 for the E-plane across all angles. It has a small size, simple design, less signal distortion, a high gain of 6.3 dBi, the fractional bandwidth percentage of 131%. and efficiency of 93.7% at 6 GHz. It has reliable performances in terms of the fidelity factor at all angles compared to the most recent works. A microwave imaging simulation for breast tumor detection is performed to detect changes in the backscattering signal in the presence or absence of a tumor with a high dielectric inclusion. S11 is quite high when measured in front of the breast model and a noticeable difference in S21 exists between the scenarios with and without a tumor in the breast model. A significant variation in the transmission parameter exists across the entire frequency range, the scenarios with and without the presence of the tumor.
Communication
Mahdieh Mohammadi; Hadi Zayyani; Mehdi Bekrani
Abstract
Target localization in wireless sensor networks (WSNs) is essential for various applications. This study investigates received signal strength (RSS)-based localization in the presence of malicious anchor nodes that intentionally alter signal power levels to mislead the fusion center (FC) and degrade ...
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Target localization in wireless sensor networks (WSNs) is essential for various applications. This study investigates received signal strength (RSS)-based localization in the presence of malicious anchor nodes that intentionally alter signal power levels to mislead the fusion center (FC) and degrade positioning accuracy. To address this challenge, we adopt a Maximum a Posteriori (MAP) estimator, which estimates the target location even when the path loss exponent is unknown. We show that the MAP estimation method can estimate the WSN unknown parameters, including the path loss exponent, the distance between the target node and anchor nodes, and the received signal strength. Simulation results demonstrate that the MAP method achieves lower localization errors than other competing approaches when the Signal-to-Noise Ratio (SNR) exceeds 10 dB, although it entails higher computational complexity in terms of simulation run time. The proposed approach is particularly efficient in applications in transportation, military operations, security, smart industries, and mapping.
Communication
Mohammad M. Fakharian
Abstract
This paper presents an optimized microwave rectifier circuit that integrates various couplers to enhance RF-to-DC conversion efficiency. A comprehensive theoretical analysis and performance evaluation of different microwave couplers are conducted to determine their impact on power distribution and impedance ...
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This paper presents an optimized microwave rectifier circuit that integrates various couplers to enhance RF-to-DC conversion efficiency. A comprehensive theoretical analysis and performance evaluation of different microwave couplers are conducted to determine their impact on power distribution and impedance matching. The study demonstrates that incorporating couplers into the rectifier circuit effectively reduces reflected power over a broad input power range. Among the evaluated configurations, the rectifier incorporating a branch-line coupler (BLC) exhibits superior RF-to-DC efficiency over a wide range of operating frequencies, input power levels, and output loads, ensuring broad impedance matching. To validate the proposed design, a rectifier circuit based on the BLC is implemented and fabricated at 2.45 GHz. The prototype consists of two identical sub-rectifying networks connected to the two output ports of the coupler, with the isolated port grounded. Experimental results indicate that the rectifier consistently achieves efficiency levels exceeding 50% for input power levels ranging from 0 to 12.5 dBm. Additionally, the design maintains high efficiency across a frequency range of 2.16 to 2.96 GHz. These findings underscore the potential of BLC-based rectifiers for high-efficiency microwave power transmission systems, offering enhanced energy harvesting capabilities and improved system performance.
Communication
Vida Esmaeili; Mahmood Mohassel Feghhi
Abstract
Objective: The Micro-Expression (ME), which automatically reveals genuine human emotions, has gained significant attention. Recognizing the ME is crucial for many real-time applications. However, there are significant challenges to overcome. For instance, the number of ME frames are limited due to their ...
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Objective: The Micro-Expression (ME), which automatically reveals genuine human emotions, has gained significant attention. Recognizing the ME is crucial for many real-time applications. However, there are significant challenges to overcome. For instance, the number of ME frames are limited due to their short duration, and the subtle facial movements can be hard to detect due to their low intensity. These challenges need to be addressed to improve ME recognition. Materials and Methods: We propose a novel method for the ME recognition in real-time. In this method, first, the apex frame is spotted using the rotated local binary pattern from six planes (RLBPS) and correlation coefficient (CC). Next, three hand-crafted methods such as the multi-color rotated local binary pattern from six planes (MRLBPS), the histograms of directed gradients from six planes (HDGS), and the histogram of image gradient direction from six planes (HIGDS) extract the features from the apex frame and its surrounding frames. Finally, the stacks of features as matrixes are fed into a three-dimensional convolutional neural network (3D-CNN), and the output is the maximum recognition rate by voting three results. Results: The proposed method has shown promising results when compared to most state-of-the-art methods. According to the results, an average precision of 99% has been obtained using our proposed method. Conclusion: The combination of the RLBPS and the CC creates a strong method for spotting the apex frame. Also, feeding the stacks of spatiotemporal features into the 3D-ResNet increases the ME recognition rate in real-time.
Communication
Mozhgan Ehsani; Mehdi Bekrani; Solyman Garousi
Abstract
The delay-and-sum (DS) beamforming and delay-weight-and-sum (DWS) beamforming are primary methods in ultrasonic imaging with phased arrays. Total focusing method (TFM) and Minimum Variance (MV) based adaptive beamforming are well-known methods within DS and DWS beamforming, respectively. The MV-based ...
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The delay-and-sum (DS) beamforming and delay-weight-and-sum (DWS) beamforming are primary methods in ultrasonic imaging with phased arrays. Total focusing method (TFM) and Minimum Variance (MV) based adaptive beamforming are well-known methods within DS and DWS beamforming, respectively. The MV-based adaptive beamforming significantly reduces interferences and provides high-resolution image compared to TFM beamforming, at the cost of high computational complexity, and sensitivity to input statistics for matrix inversion. To address these challenges, recently, iterative MV (IMV) has been proposed to alleviate computational burdens without the need for matrix inversion. The delay-multiply-and-sum (DMAS) beamforming enhances TFM beamforming performance by employing spatial information of the array signals. However, the resulting images remain susceptible to speckle and background noises in all of these beamformers. In this paper, we aim to improve these beamforming methods so that speckle and Gaussian background noise are reduced while preserving the quality of the reflective echoes in ultrasonic images. In the proposed method, a wavelet transform with a novel threshold function is applied to the received signals to initially reduce the noise, followed by the application of the beamformer. Subsequently, the coherence weighting using the denoised signals is derived, and the obtained coherence weighting is then integrated into the beamforming process. Simulation results demonstrate that the proposed method achieves a significant reduction in background noise and speckles of the above beamformer, and particularly reduces background noise and speckles of beamformer up to approximately -27dB while preserving the detection capability of reflective points.
Communication
Seyed Mostafa Alaviyan Shahri; Hamid Reza Abutalebi
Abstract
This paper deals with the problem of signal modeling using fractional-order linear prediction. In this research, we obtain the closed-form expression of the optimum sampling frequency of the One-Parameter Fractional-order Linear Prediction (OPFLP) and examine the performance when the fractional order ...
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This paper deals with the problem of signal modeling using fractional-order linear prediction. In this research, we obtain the closed-form expression of the optimum sampling frequency of the One-Parameter Fractional-order Linear Prediction (OPFLP) and examine the performance when the fractional order (alpha) is in (0<=alpha<=2). Our investigation focuses on determining optimum alpha within the individual ranges of 0<=alpha<=1 and 1<=alpha<=2 while considering various influential parameters, such as sampling frequency and environmental interferences. We initiate our study by examining the impact of the sampling frequency, a critical parameter that demands meticulous selection, on the optimal value of alpha. Simulation Results demonstrate that if the sampling rate falls within five to six times the maximum frequency of the signal under scrutiny, the optimal range for alpha resides within 1<=alpha<=2. Conversely, when the sampling frequency exceeds six times the maximum signal frequency, the optimal alpha shifts to 0<=alpha<=1. This observation underscores the crucial relationship between sampling frequency and the appropriate selection of the fractional order alpha for effective OPFLP performance. In the next step, we assess the robustness of OPFLP in handling challenging signal processing tasks, particularly in hands-free speech acquisition applications. We evaluate the model's performance and robustness against environmental interferences in three scenarios: noisy environments, reverberant environments, and noisy-reverberant settings. Simulation outcomes highlight OPFLP's superior robustness compared to second-order LP in handling environmental interferences. Furthermore, our investigations elucidate that noise exerts a more detrimental impact on OPFLP performance than reverberation, emphasizing the nuanced effects of these interferences on the model's efficacy.
Communication
Mahdi Nangir
Abstract
In this paper, we present a practical encoding and decoding scheme for the binary Wyner-Ziv problem based on graph-based codes. Our proposed scheme uses low-density generator-matrix (LDGM) codes in lossy source coding part and low-density parity-check (LDPC) codes in syndrome generation and decoding ...
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In this paper, we present a practical encoding and decoding scheme for the binary Wyner-Ziv problem based on graph-based codes. Our proposed scheme uses low-density generator-matrix (LDGM) codes in lossy source coding part and low-density parity-check (LDPC) codes in syndrome generation and decoding part. Actually, we apply Bias-Propagation algorithm for lossy source coding or binary quantization and Sum-Product algorithm for syndrome-based channel decoding. Using appropriate degree distributions for LDGM codes and optimized degree distributions for LDPC codes, we will be able to achieve close rate-distortion performance to the theoretical Wyner-Ziv bound. Also, we extend our proposed scheme for presenting a practical coding scheme for the binary Chief Executive Officer (CEO) problem. In our scheme, encodig is based on binary-quantization and Slepian-Wolf coding using source-splitting technique. It is shown that, source-splitting technique is an efficient strategy for achieving non-corner points in Slepian-Wolf rate region. We show that, this technique along with iterative message-passing algorithms can be efficient for having close rate-distortion performance to the Berger-Tung inner bound of binary CEO problem for non-corner points too.
Communication
Mahdi Kazeminia; Hamed Shahraki; Mehran Tamjidi
Abstract
Recent scene text detection methods perform superior on benchmark datasets using deep-learning frameworks. In this paper, we re-implement the state-of-the-art text detection method, character region awareness for text detection (CRAFT), which can detect individual characters of scene text images. CRAFT ...
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Recent scene text detection methods perform superior on benchmark datasets using deep-learning frameworks. In this paper, we re-implement the state-of-the-art text detection method, character region awareness for text detection (CRAFT), which can detect individual characters of scene text images. CRAFT is a character-based detection method with many advantages in detecting complex text by detecting character units and estimating the area between characters, capable of detecting texts of any shape. In the other words, we improve the detection performance of the baseline method, CRAFT, by some modifications in its architecture and proposing a training scheme that takes benefit of the advanced optimizer. The performance improvements of CRAFT are validated on three benchmark datasets: ICDAR2013, ICDAR2015, and COCO-Text. By applying the pre-trained models on COCO-Text, CRAFT shows that it cannot generalize without fine-tuning. We also improve the ICDAR2015 model and evaluate it on benchmark datasets. The evaluation results show improved precision performance compared to the original pre-trained model with fewer iterations and higher accuracy.
Communication
Fatemeh Kazemi
Abstract
In this paper, a dual-polarized antenna fed by CPW is presented. The proposed includes a conductor on the radiator and has defected ground, so it has been achieved as an omnidirectional antenna which makes it a low loss, and a simple antenna which is appropriate for a wireless communication ...
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In this paper, a dual-polarized antenna fed by CPW is presented. The proposed includes a conductor on the radiator and has defected ground, so it has been achieved as an omnidirectional antenna which makes it a low loss, and a simple antenna which is appropriate for a wireless communication system. By imposing the different circumstances of U-shape elements on the ground, the features of antennas have been improved. The scattering characteristic of the antenna are less than -20 dB with high impedance matching at 2.2GHz, 4.8GHz, and 6.6GHz. Also, the antenna covers 400 MHz bandwidth from 2 GHz to 2.4 GHz, 500 MHz bandwidth from 4.6 GHz to 5.1 GHz, and 1.3 GHz bandwidth from 5.7 GHz to 7 GHz, respectively. In addition, the maximum gain of the antenna is almost 10 dB. The simple and compact antenna with an overall size of 25x20mm2 is designed on an FR-4 substrate with 0.8 mm thickness. On the one hand, the structure is fabricated and tested. The results of the antenna have shown that the measured results agree with the simulated results; The performance of the antenna with CPW-fed, consisting of compact size, circular polarization, and suitable gain at resonance frequencies, make it a suitable choice for the communication system and the portable device.
Communication
Hadi Esmaeeli; Mehdi Rezaei
Abstract
Videos directly captured from a computer or smartphone screen have certain characteristics that differentiate them from camera-captured (CC) ones. These videos are called screen content (SC) videos whose specific encoder has been introduced as a new extension of the HEVC standard called screen content ...
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Videos directly captured from a computer or smartphone screen have certain characteristics that differentiate them from camera-captured (CC) ones. These videos are called screen content (SC) videos whose specific encoder has been introduced as a new extension of the HEVC standard called screen content coding (SCC). Most screen content applications are real-time with low delay requiring an accurate rate control. The difference in the characteristics and use of special coding tools such as palette mode, intra block copy, and adaptive color transform in this standard, have affected the mechanism of bit rate generation and control. This paper presents methods and criteria to evaluate the controllability of the bit rate of SC videos and compare it with that of CC counterparts. Furthermore, the requirements of SC video rate control are studied. The experimental results indicate that the bit rate of SC videos is much less controllable than the conventional ones so that the conventional rate-distortion models and bit rate control algorithms are not effective in coding the SC videos.
Communication
Fatemeh Geran; Nasim Mirzababaee; Shahram Mohanna
Abstract
An RF energy harvester (rectenna) consists of a broadband monopole antenna and a quad-band rectifying circuit is designed to harvest EM wave energy in the frequency range of 1.412 GHz to 8.56 GHz, which covers GSM-1800, LTE-band, Wimax, Wi-Fi, and WLAN. The initial component of the rectenna is an antenna ...
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An RF energy harvester (rectenna) consists of a broadband monopole antenna and a quad-band rectifying circuit is designed to harvest EM wave energy in the frequency range of 1.412 GHz to 8.56 GHz, which covers GSM-1800, LTE-band, Wimax, Wi-Fi, and WLAN. The initial component of the rectenna is an antenna that includes a semi-circular radiating patch with 8 circular stubs and a semicircle ground plane. The simulation results show the antenna has −10 dB impedance bandwidth at 7.148 GHz (from 1.412 GHz to 8.56 GHz). The second part of the rectenna is a rectifier circuit with a quad-band matching network for RF to DC conversion. The rectifier benefits from a two-stage Dickson rectifier using Schottky diodes. The RF-DC conversion efficiency and output DC voltage are simulated, and the maximum output voltage of the rectifier with the optimum load resistance of R=12 kΩ is 7.2 V, and the peak conversion efficiency is 65.3% when the input power to the rectifier is -4 dBm at 1.71 GHz.
