Electronics Letters最新文献

{"title":"Point2Vertex: Human Mesh Reconstruction With Hybrid Position Encoding and Dual Refinement From Point Clouds","authors":"Min Zhou,&nbsp;Ping An,&nbsp;Xinpeng Huang,&nbsp;Chao Yang","doi":"10.1049/ell2.70243","DOIUrl":"https://doi.org/10.1049/ell2.70243","url":null,"abstract":"<p>Human mesh reconstruction from point clouds has gained increasing attention in recent years. However, existing reconstruction pipelines predominantly focus on regressing human model parameters, which results in an indirect mapping between input observations and output meshes. In this letter, we introduce a point-to-vertex reconstruction method, which bypasses parameter spaces to reconstruct complete SMPL topology from partial point observations directly. Specifically, our framework employs a hierarchical approach to extract geometric information from the partial point cloud. The feature mapping process is realized via a transformer-based architecture, which integrates parametric human model priors and employs hybrid position encoding. To further improve accuracy, the dual refinement module progressively refines the reconstruction process through sequential optimization in the coordinate and vertex-level feature spaces. Experiments on SURREAL datasets demonstrate that our framework achieves state-of-the-art performance, surpassing previous methods by 18.4% in MPVE (from 19.6 to 16.0 mm) and 10.2% in MPJPE (from 17.7 to 15.9 mm).</p>","PeriodicalId":11556,"journal":{"name":"Electronics Letters","volume":"61 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/ell2.70243","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143769984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Passively Cooled BiTe Thermoelectric Generator for Operation in Harsh Environments","authors":"George Bernhardt,&nbsp;Luke Doucette,&nbsp;Ekaterina Khmeleva,&nbsp;Nuri Emanetoglu,&nbsp;Mauricio Pereira da Cunha","doi":"10.1049/ell2.70231","DOIUrl":"https://doi.org/10.1049/ell2.70231","url":null,"abstract":"<p>Energy harvesting from waste heat is becoming more prevalent as energy conservation efforts continue to increase worldwide. thermoelectric generators (TEGs) are devices that can harvest such waste heat and convert it into useful electrical power. Traditionally, active cooling methods are used to maximize the thermal gradient across a TEG module in order to optimize the energy conversion process. However, active cooling is impractical for a significant number of industrial harsh-environment applications. To examine the feasibility of using passively cooled TEG devices for producing useful electrical power, a bismuth telluride (BiTe) TEG device was fabricated and tested from 200°C to 290°C on the hot side, without active cooling on the cold side. As such, the temperature difference across the TEG device remained consistent at approximately 50°C over the range of hot-side temperatures tested. Under these conditions, the BiTe TEG device produced a single-couple average voltage of 8 mV over the range of test temperatures, and single-couple powers up to 0.10 mW at 290°C, despite the lack of active cooling. These results show the capability of TEG module integration to power electrical circuits for high-temperature harsh-environment applications operating under passive cooling.</p>","PeriodicalId":11556,"journal":{"name":"Electronics Letters","volume":"61 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/ell2.70231","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143749697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intrinsic Modulation Response and Electrical Parasitics in Oxide-confined Vertical-Cavity Surface-Emitting Lasers Based on Single or Multiple Apertures","authors":"Nikolay N. Ledentsov,&nbsp;Nikolay Ledentsov Jr.,&nbsp;Łukasz Chorchos,&nbsp;Oleg Yu. Makarov,&nbsp;Vitaly A. Shchukin,&nbsp;Vladimir P. Kalosha,&nbsp;Ilya E. Titkov,&nbsp;Jaroslaw Turkiewicz","doi":"10.1049/ell2.70234","DOIUrl":"https://doi.org/10.1049/ell2.70234","url":null,"abstract":"<p>Small aperture (∼2 µm) oxide-confined single-mode (SM) Vertical-Cavity Surface-Emitting Lasers (VCSELs) are capable of intrinsic optical modulation bandwidth above 42 GHz at low currents (∼2 mA). The measured optical bandwidth is limited to ∼36-38 GHz by the VCSEL resistance and capacitance (RC parasitics). To match requirements for industrial VCSELs, we applied a single mesa multi-aperture (MA) single-mode (SM) VCSEL design. The design is based on 4 diamond-shaped apertures at ∼10 µm pitch and an effective diameter of a single aperture of ∼1.7-2 µm. Higher capacitance of the large VCSEL mesa is compensated by a reduced resistance (50Ω) of the device, allowing optical bandwidth <i>f</i>_-3dBo ∼32 GHz. The intrinsic optical bandwidth <i>f</i>_-3dBo of ∼45 GHz is extracted. MA SM VCSEL allows narrow spectral width and error-free 50-Gbaud data transmission over 200 m OM5 multimode fibre (MMF).</p>","PeriodicalId":11556,"journal":{"name":"Electronics Letters","volume":"61 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/ell2.70234","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143762083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deep-Learning-Based Pilot Optimization for Near-Field Channel Estimation in Ultra-Massive MIMO","authors":"Zexian Chen,&nbsp;Kunpeng Song,&nbsp;Zhengwei Qu,&nbsp;Yunze Zhang,&nbsp;Yong Shang","doi":"10.1049/ell2.70227","DOIUrl":"https://doi.org/10.1049/ell2.70227","url":null,"abstract":"<p>As sixth-generation (6G) communication technology evolves, the increase in frequency and the number of antennas has made traditional far-field channel estimation methods less effective. This paper proposes a deep neural network (DNN)-based method to optimize pilot signals for near-field channel estimation in ultra-massive multiple-input multiple-output (MIMO) systems. By optimizing the pilot signals, the method can accurately estimate the distance and angle of scatterers, addressing the challenges of traditional sparse estimation techniques. Simulation results demonstrate that this approach improves estimation accuracy compared to conventional methods.</p>","PeriodicalId":11556,"journal":{"name":"Electronics Letters","volume":"61 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/ell2.70227","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143749286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Balancing Robustness and Efficiency in Embedded DNNs Through Activation Function Selection","authors":"Jon Gutiérrez-Zaballa,&nbsp;Koldo Basterretxea,&nbsp;Javier Echanobe","doi":"10.1049/ell2.70210","DOIUrl":"https://doi.org/10.1049/ell2.70210","url":null,"abstract":"<p>Machine learning-based embedded systems for safety-critical applications, such as aerospace and autonomous driving, must be robust to perturbations caused by soft errors. As transistor geometries shrink and voltages decrease, modern electronic devices become more susceptible to background radiation, increasing the concern about failures produced by soft errors. The resilience of deep neural networks (DNNs) to these errors depends not only on target device technology but also on model structure and the numerical representation and arithmetic precision of their parameters. Compression techniques like pruning and quantisation, used to reduce memory footprint and computational complexity, alter both model structure and representation, affecting soft error robustness. In this regard, although often overlooked, the choice of activation functions (AFs) impacts not only accuracy and trainability but also compressibility and error resilience. This paper explores the use of bounded AFs to enhance robustness against parameter perturbations, while evaluating their effects on model accuracy, compressibility, and computational load with a technology-agnostic approach. We focus on encoder–decoder convolutional models developed for semantic segmentation of hyperspectral images with application to autonomous driving systems. Experiments are conducted on an AMD-Xilinx's KV260 SoM.</p>","PeriodicalId":11556,"journal":{"name":"Electronics Letters","volume":"61 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/ell2.70210","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143741693","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Framework for Online Estimation of High Frequency Converter Circuit Parameters","authors":"Nicholas Green,&nbsp;Mohammed Agamy","doi":"10.1049/ell2.70230","DOIUrl":"https://doi.org/10.1049/ell2.70230","url":null,"abstract":"<p>In this paper a parameter estimation method of high frequency switching power converters is proposed. Parameters are estimated through measurement of basic circuit voltage and current quantities and using simple feed forward neural networks to establish correlations between circuit parameter variations and general converter performance. This allows the estimation of internal semiconductor device or passive component parameters that would be challenging to measure directly. This approach serves as a promising enabler for power converter digital twins and for converter health monitoring. The proposed framework is developed and verified for an LLC resonant converter. Parameter predictions achieved mean absolute errors below 4.12% and an average MAE of 1.57% for all parameters.</p>","PeriodicalId":11556,"journal":{"name":"Electronics Letters","volume":"61 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/ell2.70230","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143726921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing Electric Wheelchair Safety via Battery State of Charge Estimation With PCC–NSSR–LSTM Method","authors":"Panpan Hu,&nbsp;Chi-Wing Tsang,&nbsp;Xiao-Ying Lu,&nbsp;Chun Yin Li,&nbsp;Chi Chung Lee","doi":"10.1049/ell2.70228","DOIUrl":"https://doi.org/10.1049/ell2.70228","url":null,"abstract":"<p>This study explores a novel algorithm created to predict the state of charge (SOC) of batteries in electric wheelchairs (EWs) to improve EW safety by adjusting SOC thresholds and reducing consumer range anxiety. It involves collecting experimental data from lithium iron phosphate (LFP) battery cells over 1500 cycles at 25°C, encompassing various parameters. With the Pearson correlation coefficient (PCC), a select set of key parameters including voltage, temperature, dQ/dV (capacity increase to voltage increase ratio) are chosen as inputs for non-linear state space reconstruction long short-term memory (NSSR-LSTM) neural networks, facilitating precise SOC predictions. The study showcases the precision of SOC predictions by revealing outcomes for different cycles, such as 900, 1000 and 1100. In addition to EWs, the proposed PCC–NSSR–LSTM method is also applicable to other mobility devices, including electric bicycles, golf carts and similar vehicles.</p>","PeriodicalId":11556,"journal":{"name":"Electronics Letters","volume":"61 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/ell2.70228","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143726851","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Switchable Bulk Acoustic Resonator Based on AlN/Al0.7Sc0.3N Films","authors":"Jinghong Lu,&nbsp;Chongyang Huo,&nbsp;Xuanqi Huang,&nbsp;Weimin Li,&nbsp;Zhiqiang Mu,&nbsp;Wenjie Yu","doi":"10.1049/ell2.70241","DOIUrl":"https://doi.org/10.1049/ell2.70241","url":null,"abstract":"<p>Tuneable filters are essential for the development of the reconfigurable RF modules. This work demonstrates a switchable bulk acoustic wave resonator utilizing a double-layer structure of piezoelectric AlN and ferroelectric Al_0.7Sc_0.3N films. By applying a DC bias, the resonator achieves frequency switching through the control of the polarization in the Al_0.7Sc_0.3N layer. The resonator exhibits dual-mode operation, with tuneable resonant frequencies between 6.80 and 16.73 GHz, while maintaining considerable electromechanical coupling efficiency at high frequencies. These characteristics reveal great potential of this device for the development of reconfigurable acoustic filters and RF modules in advanced wireless communication systems.</p>","PeriodicalId":11556,"journal":{"name":"Electronics Letters","volume":"61 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/ell2.70241","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143735508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Low Power CMOS Stochastic Bit Based Ising Machine and Its Application to Graph Coloring Problem","authors":"Honggu Kim,&nbsp;Dongjun Son,&nbsp;Yerim An,&nbsp;Yong Shim","doi":"10.1049/ell2.70236","DOIUrl":"https://doi.org/10.1049/ell2.70236","url":null,"abstract":"<p>The Ising spin model is an efficient method for solving combinatorial optimization problems (COPs) but faces challenges in conventional Von-Neumann architectures due to high computational costs, especially with the growing data volume in the IoT era. To address this problem, we proposed low power CMOS stochastic bit based Ising machine to efficiently compute COPs. By adopting compute-in-memory (CIM) approach for parallel spin computation, we achieved energy efficient spin computing. Furthermore, we harnessed the inherent randomness of CMOS stochastic bit to prevent Ising computing process from being stuck into local minima, effectively mitigating the power penalty associated with the random number generators (RNGs) in the conventional CMOS based Ising machines. We demonstrated the feasibility of our design by solving NP-complete graph coloring problem with four vertices and three colors using TSMC 65 nm GP process. Moreover, the proposed CMOS stochastic bit based spin unit consumes the lowest power/spin among the state-of-the-art Ising machine researches, with power/spin of 1.07 <span></span><math>\u0000 <semantics>\u0000 <mrow>\u0000 <mi>μ</mi>\u0000 <mi>W</mi>\u0000 </mrow>\u0000 <annotation>$mu{rm W}$</annotation>\u0000 </semantics></math> and energy/spin of 107 fJ.</p>","PeriodicalId":11556,"journal":{"name":"Electronics Letters","volume":"61 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/ell2.70236","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143726899","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A 26.5–29.5 GHz 256-Element Dual-Polarized Integrated Phased Array With 61-dBm EIRP and 400-MHz 64-QAM Modulation","authors":"Huiqi Liu,&nbsp;Dixian Zhao","doi":"10.1049/ell2.70238","DOIUrl":"https://doi.org/10.1049/ell2.70238","url":null,"abstract":"<p>A dual-polarized 256-element integrated phased-array antenna is presented, with an operating frequency range covering the 5G NR N257 band (i.e., 26.5–29.5 GHz). By adopting an integrated phased array technology with cost-effective fabrication, multifunctional circuits can be implemented in high-density configurations, thereby reducing system footprint without sacrificing performance. A design methodology for the dual-polarized antennas with high isolation is employed to enhance the cross-polarization suppression. The proposed phased array supports scanning angles of <span></span><math>\u0000 <semantics>\u0000 <mo>±</mo>\u0000 <annotation>$pm$</annotation>\u0000 </semantics></math><span></span><math>\u0000 <semantics>\u0000 <msup>\u0000 <mn>40</mn>\u0000 <mo>∘</mo>\u0000 </msup>\u0000 <annotation>$40^circ$</annotation>\u0000 </semantics></math> and <span></span><math>\u0000 <semantics>\u0000 <mo>±</mo>\u0000 <annotation>$pm$</annotation>\u0000 </semantics></math><span></span><math>\u0000 <semantics>\u0000 <msup>\u0000 <mn>60</mn>\u0000 <mo>∘</mo>\u0000 </msup>\u0000 <annotation>$60^circ$</annotation>\u0000 </semantics></math> in the azimuth and elevation planes, respectively. The typical effective isotropic radiated power (EIRP) of the dual-polarized antenna is greater than 61 dBm with the 5G NR 400-MHz 64-QAM modulation (EVM <span></span><math>\u0000 <semantics>\u0000 <mo>&lt;</mo>\u0000 <annotation>$&lt;$</annotation>\u0000 </semantics></math> 5.6<span></span><math>\u0000 <semantics>\u0000 <mo>%</mo>\u0000 <annotation>$%$</annotation>\u0000 </semantics></math>).</p>","PeriodicalId":11556,"journal":{"name":"Electronics Letters","volume":"61 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1049/ell2.70238","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143726920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}