Hasil untuk "Electric apparatus and materials. Electric circuits. Electric networks"

V.B. Murali Krishna, Hossein Fotouhi, Rajesh Cheruku et al.

The transition to truly smart cities demands more than layered technologies; it requires convergent intelligence that unifies physical sensing, adaptive control, and ethical security. This editorial paper brief about the special issue entitled “Measurement, Control and Security of Systems for Smart Cities”. As smart cities are among the most active research areas, the call for papers for this special issue, “VSI: Systems for Smart Cities” attracted a wide range of manuscripts spanning multiple disciplines, including Computer Science, Electrical and Electronics Engineering, Communication Engineering, Civil Engineering, Mechanical Engineering, Urban Construction, Artificial Intelligence and Machine Learning, Cybersecurity, and Renewable Energy etc. Notably, authors from 16 different countries, including Algeria, Chile, China, Egypt, England, Ethiopia, India, Iran, Jordan, Kosovo, Nigeria, Portugal, Saudi Arabia and United Arab Emirates have contributed their research articles. In this editorial, we synthesize insights from all 30 published articles to present a holistic vision of next-generation urban ecosystems. Together, these works span renewable energy, structural health, healthcare, transportation, noise pollution, public space, and data security, these works collectively redefine what it means to build intelligent infrastructure that is sustainable, equitable, resilient, and trustworthy. We organize these advances around three interwoven pillars: (1) Measurement for Awareness, (2) Control for Adaptation, and (3) Security and Ethics for Trust-and demonstrate how fractional-order controllers, lightweight crack detectors, edge-based triage systems, multimodal transport models, and secure data-mining frameworks all contribute to a human-centered urban future. This synthesis serves as both a technical roadmap and a philosophical compass for the responsible evolution of smart cities.

Sotaro Kageyama, Kazuki Okamoto, Shinnosuke Yasuoka et al.

Abstract The piezoelectric and ferroelectric applications of heterovalent ternary materials are not well explored. Epitaxial MgSiN2 films are grown at 600 °C on (111)Pt//(001)Al2O3 substrates by the reactive sputtering method using metallic Mg and Si under the N2 atmosphere. Detailed X‐ray diffraction measurements and transmission electron microscopy observations revealed that the epitaxially grown films on the substrates have a hexagonal wurtzite structure with c‐axis out‐of‐plane orientation. The random occupation of this structure by Mg and Si differs from that of the previously reported structure in which these two cations periodically occupy the cationic sites. However, the lattice spacings closely approximate those that are previously reported, irrespective of the ordering, and they are almost comparable with those of (Al0.8Sc0.2)N. The wide bandgap of >5.0 eV in deposited MgSiN2 is compatible with that of AlN and suggests durability against the application of strong external electric fields, possibly to induce polarization switching. In addition, MgSiN2 is shown to have piezoelectric properties with an effective d33 value of 2.3 pm V−1 for the first time. This work demonstrates the compositional expansion of hexagonal wurtzite to heterovalent ternary nitrides for novel piezoelectric materials, whose ferroelectricity is expected.

Mohamadali Malakoutian, Kelly Woo, Dennis Rich et al.

Abstract Advancing Silicon (Si) technology beyond Moore's law through 3D architectures requires highly efficient heat management methods compatible with foundry processes. While continued increases in transistor density can be achieved through 3D architectures, self‐heating in the upper tiers degrades the performance. Self‐heating is a critical problem for high‐power, high‐frequency, wide bandgap, and ultra‐wide bandgap devices as well. Diamond, known for its exceptional thermal conductivity, offers a viable solution in both these cases. Since thermal boundary resistance (between the channel/junction and diamond plays a crucial role in overall thermal resistance, this study investigates various dielectrics for interface engineering, such as Silicon dioxide (SiO2), amorphous‐ Silicon Carbide (a‐SiC), and Silicon Nitride (SiNx), to make a phonon bridge at gallium nitride (GaN)‐diamond and Si‐diamond interfaces. The a‐SiC interlayer reduces diamond/GaN (<5 m2K per GW) and diamond/Si (<2 m2K per GW) thermal boundary resistances by linking low‐ and high‐frequency phonons, boosting phonon transport through the interface. Engineered interfaces enhance heat spreading from the channel/junction and rule out premature failure.

Yifei Zhu, Zhenxuan Luan, Dawei Feng et al.

The escalating demand for high-performance and energy-efficient electronics has propelled 3D integrated circuits (3D ICs) as a promising solution. However, major obstacles have been the lack of specialized electronic design automation (EDA) software and standardized design flows for 3D chiplets. To bridge the gap, we introduce Open3DFlow,<xref ref-type="fn" rid="fn1">1</xref> an open-source design platform for 3D ICs. It is a seven-step workflow that incorporates essential ASIC back-end processes while supporting multi-physics analysis, such as through silicon via (TSV) modeling, thermal analysis, and signal integrity (SI) evaluations. To illustrate all functionalities of <italic>Open3DFlow</italic>, we use it to implement a 3D RISC-V CPU design with a vertically stacked L2 cache on a separated die. We harden both CPU logic and 3D-cache die in a GlobalFoundries <inline-formula> <tex-math notation="LaTeX">$0.18\mu $ </tex-math></inline-formula>m (GF180) process with open-source PDK support. We enable face-to-face (F2F) coupling of the top and bottom die by constructing a bonding layer based on the original technology file. <italic>Open3DFlow</italic>&#x2019;s open-source nature allows seamless integration of custom AI optimization algorithms. As a showcase, we leverage large language models (LLMs) to help the bonding pad placement. In addition, we apply LLM on back-end Tcl script generations to improve design productivity. We expect <italic>Open3DFlow</italic> to open up a brand-new paradigm for future 3D IC innovations.

Keval Hadiyal, Ramakrishnan Ganesan, R. Thamankar

Abstract Quantum effects in nanowires and nanodevices can potentially revolutionize the device concepts with multi‐functionalities for future technologies. Memristive devices which undergo transition from high resistance state to low resistance state involve nanoscale conduction paths can show quantum effects at room temperature. Here, Mn3O4 nanowires based memristor showing very reliable resistive switching at very low voltages and with ON/OFF States ratio ∼ 103 is reported. The switching device can also be programmed to multiple memory states (up to 16 states ∼ 24). Since the conduction paths are geometrically constrained along the nanowires, quantized conductance steps are observed. Step‐wise conductance jumps are observed during the SET and RESET process with better control along RESET process. Conductance jumps range between 1 and 9 G0. The nanowire devices show very consistent resistive switching up to 100 °C. These measurements confirm extremely stable nanowire based resistive switching devices which can be used for next‐generation memories showing quantum effects in neuromorphic computing architectures.

Noual Amina, Touati Zine-eddine, Messai Zitouni et al.

This paper presents a numerical simulation study of an E-mode AlInGaN/AlN/GaN metal oxide semiconductor high electron mobility transistor (MOSHEMT) grown on an ultra-wide bandgap beta oxide gallium substrate (UWBG-β-Ga2O3) using the two-dimensional device simulator Silvaco-Atlas. The study investigates the influence of aluminum (x) and indium (y) concentrations and the downscaling of the AlxInyGazN barrier layer on various electrical characteristics, including polarization, 2D electron gas (2DEG) concentration, sheet charge density, threshold voltage, and Ion/Ioff ratio. The impact of introducing an AlN spacer layer is also examined. The results demonstrate that increasing the alloy composition and barrier thickness leads to significantly improved analog performance, accompanied by a reduction in the threshold voltage. Notably, an optimal 20nm-Al0.80In0.18Ga0.02N barrier grown over β-Ga2O3 substrate achieves a high 2DEG carrier density of 1.54 × 1013 cm-2, a positive threshold voltage of 1.09 V, and a higher Ion/Ioff ratio of around 5. 5 × 1012.The proposed numerical simulation model proves to be well-suited for the investigation of quaternary nitride-based MOSHEMTs grown on UWBG-β-Ga2O3 substrates, offering valuable insights prior to device manufacturing.

Aravinda Perera, Roy Nilsen

This article presents a position-sensorless Interior Permanent Magnet Synchronous Machine (IPMSM) drive scheme that incorporates an open-loop stator current predictor to identify electrical parameters and improve observer performance. Unlike classical observers, the proposed open-loop, full-order model is inherently sensitive to discrepancies between the physical and model parameters. Capitalizing on this sensitivity through current prediction error gradients (PEGs), the parameter estimator scheme identifies the temperature sensitive parameters, i.e., the permanent magnet flux linkage Ψm and stator resistance Rs. An offline experimental method, utilizing the same prediction model, is proposed for mapping the inductance-current relationship, which is subsequently implemented in the processor using a look-up table (LUT). Rotor position and speed are estimated via an Active Flux Observer, with real-time updates to all model parameters. Furthermore, a novel approach for tuning the estimation gain matrix using customized Hessian functions is presented, enabling improved simultaneous identification of Ψm and Rs. Experimental validation is conducted on a 3 kW IPMSM drive, with control and estimation routines implemented on a Zynq System-on-Chip (SoC)-based industrial embedded control platform. Results demonstrate that the proposed schemes enhance observer stability, precision, and robustness to parameter variations compared to conventional observers without parameter adaptation.

Minjeong Ryu, Jae Seung Woo, Yeonwoo Kim et al.

Abstract Single ambipolar ferroelectric memcapacitor‐based time‐domain (TD) content‐addressable memory (CAM) is proposed and experimentally demonstrated. The proposed TD CAM design effectively resolves the critical challenges of limited integration density and computational reliability in conventional ferroelectric memcapacitor‐based capacitive CAMs. The band‐reject‐filter‐shaped and symmetric capacitance‐voltage characteristics with high dynamic range of a gated p‐i‐n diode‐structured ferroelectric memcapacitor are leveraged. This CAM performs dual‐edge search operations, where the Hamming distance (HD) between entry and query vectors is computed based on the modulation of the variable capacitance of cells. The propagation delay of the TD CAM output signal is linearly correlated with the computed HD, enabling improved search accuracy and sensing margin. The error‐free classification of previously unseen classes in a five‐way one‐shot learning task indicates the feasibility of the proposed TD CAM as an associative memory within memory‐augmented neural networks toward real‐world implementations. Moreover, modeling results confirm that the proposed operation scheme maintains robustness against process variations and interconnect parasitics in massive arrays of highly scaled devices. Overall, the proposed TD CAM array offers exceptional compactness, linearity, and in‐memory search reliability, considerably outperforming the conventional ferroelectric CAMs for HD computation.

Tokunbo Ogunfunmi

Minhyun Jung, Seungyeob Kim, Junghyeon Hwang et al.

Abstract The development of artificial tactile receptor systems is important in the fields of prosthetic devices, interfaces for the metaverse, and sensors. A pressure sensor and memory device may be used in this system to replicate the tactile detecting capabilities of human skin. The implementation of systems that take into account mass production and miniaturization is still difficult. Here, a flexible artificial tactile receptor built using conventional semiconductor processes that combine a vertically stacked piezoelectric sensor with neuromorphic memory is presented. As a fundamental component for both sensors and memory, hafnium zirconium oxide (HZO) formed by using semiconductor deposition technique is introduced. Due to its exceptional piezoelectric performance, the morphotropic phase boundary of HZO is studied. The entire materials and processes are highly compatible with conventional semiconductor processes, including microwave annealing‐based low‐temperature crystallization. Even after 10,000 times of bending stress, the sensor and memory constructed on a flexible substrate exhibit consistent pressure detection characteristics over a wide range of 2–25 kPa. The feasibility of the approach is further demonstrated by a deep neural network simulation, which reached 90.8% braille recognition accuracy. Wearable electronics and medical devices are two examples of industrial domains that can use these flexible, exceptionally durable devices.

Hyeon Jun Hwang, Seung Mo Kim, Byoung Hun Lee

Abstract In this study, the domain switching mechanism of ferroelectric HZO thin films is investigated by analyzing the bulk charge of a graphene field‐effect transistor with an HZO dielectric device by using a pulsed IV measurement method. The domain switching speed, which is generally difficult to observe from a typical DC‐IV analysis of metal‐oxide‐semiconductor field‐effect transistors using a parameter analyzer, is investigated via the fast pulsed IV analysis method. Based on the measurements, most of the ferroelectric HZO domains are fast switched within 100 ns; however, domains that require a longer switching time in the order of 1 ms are also identified. Short pulses can be continuously applied to minimize the influence of other domains that are not switched by the switched domain. The feasibility of partial switching of the domains, which can be utilized for the multi‐functional operation of ferroelectric HZO devices, is observed. The results suggest that further investigation of the physical properties of slow‐switching domains is necessary to develop future synaptic array applications.

Shova Neupane, Serguei Chiriaev, William Greenbank et al.

Polypropylene (PP) films have a wide range of applications, e.g. as dielectric materials for metallized film capacitors. In this article, we present a method for thickness reduction of PP films by ion irradiation, which has a direct effect on device capacitance. We show that the thickness of PP layers can be reduced by irradiation with He+ ions and controlled on the nanometer scale by the irradiation dose. The effect of different thin metal film coatings on PP surface was also investigated. The metal coatings were used for two reasons: they function as one of the metal electrodes in the capacitor structure, and they minimize sample charging during ion irradiation. Three different metallization materials were investigated: 5 nm Pt60Pd40, 5 nm Au, and 15 nm Al. We studied two technologically relevant PP films: the thinnest commercially available biaxially oriented polypropylene (BOPP) and spin-coated polypropylene (SC-PP) thin films. The irradiation was done with a focused Helium-ion beam (He-FIB) in a Zeiss Orion NanoFab Microscope at a landing energy of 30 keV with doses in a range of 5.4 × 10–5 nC/μm2 to 8.1 × 10–3 nC/μm2. An atomic force microscope (AFM) was used to analyze the details of surface modification: the surface height of the irradiated regions and surface morphology changes caused by the irradiation. For all applied doses, the Al-coated samples demonstrated smaller surface-height reduction compared to the Pt60Pd40 and Au-coated samples. We speculate that the possible factors responsible for this effect include differences in the thickness and the crystalline-grain orientation (texture) of the metallization films. Both BOPP and spin-coated PP presented surface ridges at the borders between the irradiated and non-irradiated regions. It can be attributed to the mechanical strain induced by the material modification.

Bowen Zhang, Shi Chen, Guo-Quan. Lu et al.

In this paper, excellent thermo-mechanical reliability of resin-free silver sintering for large-area (20 × 20 mm2) bonding was successfully achieved by using a trimodal particle system composed of nano-, submicron-, and micron-sized Ag particles. After 1000 cycles of the thermal shock (TS) test, the transient thermal impedance (Zth) increase of the proposed resin-free silver paste sintered at 180°C under 2 MPa and 5 MPa is only 5.8% and 6.1%, respectively. Due to the avoidance of resin degradation, the obtained resin-free silver paste as-sintered under 5 MPa exhibt outstanding shear strength (>12.5 MPa) even after 1000 cycles TS test. The obtained cross-sectional microstructure can confirms the excellent thermo-mechanical reliability of the sintered resin-free silver paste, which exhibits a denser and more homogeneous bonding layer with a porosity as low as 12.5%. Furthermore, distinct indications of plastic flow can be observed on the fracture surfaces of corresponding joints before and after aging, which further confirm the superiority of proposed resin-free sintering method. The development of novel resin-free silver paste successfully promotes the thermo-mechanical reliability of silicon carbide (SiC) power devices at a low processing temperature of 180°C, and greatly benefits the practical application of SiC power devices.

B. Raviprasad, Chinnem Rama Mohan, G. Naga Rama Devi et al.

The Internet of Things (IoT) offers users a wide variety of facilities because it interconnects billions of smart devices. However, when connected to wireless connections, unlimited access to IoT gadgets poses potential risks. As it eases cost constraints on sensor nodes, the cloud service with IoT networks has received greater attention. In addition, the high complexity of the distribution and networking of IoT makes them vulnerable to attacks. Intrusion detection systems (IDSs) are selected to ensure the security of reliable information and operations. IDS successfully detects anomalies in complex network situations and guarantees network security. Deep Convolution Network (DCN) IDS have a slow learning curve and poor categorization precision. Deep Learning (DL) methods are often used in a wide range of safety data processing, imaging, and signal processing like Poor transfer learning ability, reusability of modules, and integration. To overcome the constraints of Machine Learning (ML) IDS is intended to provide a comprehensive mechanism to learn the detection mechanism for multicloud IoT environments. The proposed IDS approach increases training efficiencies while increasing detection accuracy. Experimental investigations of the proposed system using the considered database confirms that the performance of the proposed system is capable and in the range of acceptance with relative to existing methods. Further, achieving detection capability, reliability, and accuracy of 97.51, 96.28, and 94.41% respectively are achieved.

Jae-Sun Seo

Machine learning (ML) and artificial intelligence (AI) have been successful in many practical applications, e.g., image/speech/video recognition, object detection/tracking, natural language processing, etc. To efficiently execute such AI/ML algorithms, there have been large advances in custom hardware accelerator designs, such as digital systolic arrays of processing engines (PEs), and analog or digital circuits for in-/near-memory computing for deep neural networks (DNNs) <xref ref-type="bibr" rid="ref1">[1]</xref>, <xref ref-type="bibr" rid="ref2">[2]</xref>.

S. Subburaj, S. Murugavalli

Every day we see many people with disabilities like the deaf, the dumb and the blind, etc. Sign language is one of the communication tools for the hard-of-hearing people community and common people community. But, normal people find it hard to understand the sign language and gestures of the deaf and dumb. Many tools can be used to translate the sign language created by the disabled into a form that normal people can understand. The studies are based on various image acquisition, preprocessing, hand gesture segmentation, extraction of features, and classification methods. This paper aims to research and examine the methods employed within the SLR systems, and the classification methods used, and to propose the most promising technique for future research. Due to the latest advancement in classification methods, a few of the currently proposed works specifically contribute to classification methods, together with hybrid techniques and deep learning. This paper specializes in the classification strategies utilized in earlier Sign Language Recognition. Based on our review, HMM-based techniques were explored significantly in previous studies, which include modifications. Deep learning consisting of convolutional neural networks has become popular over the past five years.

Márcio J Oliveira, Alaelson Vieira Gomes, André Rocha Pimenta

Este trabalho apresenta um compósito, formado por alumina e polietileno de baixa densidade, para utilização em proteções balísticas, principalmente coletes. O material foi fabricado com 70% em peso de alumina e 30% em peso de polietileno de baixa densidade e submetido a testes balísticos e caracterizações físicas e térmicas. Após o ensaio balístico, a superfície de fratura foi caracterizada por microscopia eletrônica de varredura. Os resultados indicaram que uma placa de 15 mm do compósito é capaz de resistir de forma adequada a impactos balísticos de projéteis .22 LR. O compósito apresentou baixa absorção de água, suportou altas temperaturas e demonstrou boa estabilidade térmica. Contudo, apesar de aumentar o tempo de propagação de chama do polietileno, a adição de alumina não foi capaz de conferir propriedade de auto extinção de chama. Conclui-se que o compósito possui bom desempenho para proteções balísticas de projéteis .22 LR.

Miha Hiti

The paper presents an evaluation of synchronization issues when performing material testing machine calibration using continuous loading. A procedure for the compensation of a rangewide error in calibrated force values is proposed based on a correction factor determined from static and transient errors difference at a chosen force step. The procedure was applied for a calibration of a testing machine with a 20 kN force transducer and 200 N/s to 2000 N/s loading rates. The results show good performance of the compensation technique, reducing calibration errors to below 1% in non-synchronized signals even under unknown filter and delay setting.

Sinisa Prugovecki, Mirna Fakin, Mirna Lerotic

This paper describes LorisQ, fully digital solution for equipment maintenance which already includes some important features of digital calibration certificates (DCC) even before their standardization. More importantly, it provides user-friendly environment for future standardized DCCs to be used and exchanged between calibration clients and providers. LorisQ connects people within a team (laboratory, department, or organization) and improves their collaboration on measuring equipment maintenance in general and calibration specifically, but it also connects a team of equipment users with any of their calibration or any other maintenance service providers. It enables 24h access to complete instrument documentation including DCCs and everything else important to the user.

Tomofumi Shimoda, Wataru Kokuyama, Hideaki Nozato

Micro-vibration is an important measurement target in various fields, such as infrastructure health monitoring or satellite operation. In this study, the effect of background noise in calibrating vibration sensors at small amplitudes is discussed. The primary noise sources in the calibration system are the seismic vibration, self-noise of the laser interferometer, and cyclic error. A vibration isolation system was introduced, and the laser interferometer was replaced to reduce the noise sources. These upgrades reduced the background noise down to 10−7 (m/s2)/Hz1/2 around 10 Hz. Using the system, a servo accelerometer was calibrated with an acceleration amplitude of 0.01 m/s2. The calibration repeatability below 0.1% for the sensitivity was achieved between 0.4 Hz and 100 Hz.