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Namju Kim Jungyeop Oh Sungkyu Kim Jun-Hwe Cha Junhwan Choi Sung Gap Im Sung-Yool Choi Byung Chul Jang 《Advanced functional materials》2024,34(16):2305136
Artificial Intelligence (AI) technology has attracted tremendous interest in the medical community, from image analysis to lesion diagnosis. However, progress in medical AI is hampered by a lack of available medical image datasets and labor-intensive labeling processes. Here, it is demonstrated that a large number of annotated, realistic chest X-ray images can be generated using a state-of-the-art generative adversarial network (GAN) that exploits noise produced by stochastic in-memory computing of memristor crossbar arrays. Memristors based on polymer film with high thermal resistance can increase the stochasticity of the tunneling distance for randomly ruptured conductive filaments via excessive Joule heating, thus generating true random numbers required for creating naturally diverse images in GAN. Using StyleGAN2-adaptive discriminator augmentation (ADA), high-quality chest X-ray images with and without pneumothorax are successfully augmented while maintaining a good Frechet inception distance score. The results provide a cost-effective solution for preparing privacy-sensitive medical images and labeling to develop innovative medical AI algorithms. 相似文献
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Chenyu Zhuge;Yukun Zhang;Jiandong Jiang;Xiang Li;Yanfei Zhao;Yujun Fu;Qi Wang;Deyan He; 《Small (Weinheim an der Bergstrasse, Germany)》2024,20(42):2400599
Memristors are used in artificial neural networks owing to their exceptional integration capabilities and scalability. However, traditional memristors are hampered by limited resistance states and randomness, which curtails their application. The migration of metal ions critically influences the number of conductance states and the linearity of weight updates. Semi-metal filaments can provide subquantum conductance changes to the memristors due to the smaller single-atom conductance, such as Sb (≈0.01 G0 = 7.69 × 10−7 S). Here, a memristor featuring an active electrode composed of semi-metal Sb is introduced for the first time. This memristor demonstrates precise conductance control, a large on/off ratio, consistent switching, and prolonged retention exceeding 105 s. Density functional theory (DFT) calculations and characterization methods reveal the formation of Sb filaments during a set process. The interaction between Sb and O within the dielectric layer facilitates the Sb filaments' ability to preserve their morphology in the absence of electric fields. 相似文献
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Miao Hu Catherine E. Graves Can Li Yunning Li Ning Ge Eric Montgomery Noraica Davila Hao Jiang R. Stanley Williams J. Joshua Yang Qiangfei Xia John Paul Strachan 《Advanced materials (Deerfield Beach, Fla.)》2018,30(9)
Using memristor crossbar arrays to accelerate computations is a promising approach to efficiently implement algorithms in deep neural networks. Early demonstrations, however, are limited to simulations or small‐scale problems primarily due to materials and device challenges that limit the size of the memristor crossbar arrays that can be reliably programmed to stable and analog values, which is the focus of the current work. High‐precision analog tuning and control of memristor cells across a 128 × 64 array is demonstrated, and the resulting vector matrix multiplication (VMM) computing precision is evaluated. Single‐layer neural network inference is performed in these arrays, and the performance compared to a digital approach is assessed. Memristor computing system used here reaches a VMM accuracy equivalent of 6 bits, and an 89.9% recognition accuracy is achieved for the 10k MNIST handwritten digit test set. Forecasts show that with integrated (on chip) and scaled memristors, a computational efficiency greater than 100 trillion operations per second per Watt is possible. 相似文献
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AbstractA gas discharge lamp is a device, which operates as a light source by producing electrical discharge in ionized gaseous medium. Discharge lamps are commonly used in the market and according to their physical properties they can be mainly classified in three different categories: high pressure, low pressure and high-intensity lamps. Ionized gases have tendency to produce ongoing discharges and finally electrical arcs, which exhibit memristor characteristics proposed by Leon Chua. This paper introduces a novel fully floating memristor circuit emulator with tunable threshold characteristics which mimic discharge lamp characteristics. In order to investigate discharge lamp characteristics a test set-up is designed and commercially available discharge lamps are tested. The proposed memristor circuit displays distinctive characteristics in contrast to well-known smooth switching memristor characteristics in terms of hard switching capability. Proposed memristor has unique switching behavior and fully capable of modeling discharge lamps since it satisfies required zero-crossing, pinched hysteresis and frequency dependent characteristics of the discharge lamps. The comparisons of the current-voltage characteristics for both memristor and discharge lamps are supplied and investigated. 相似文献
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Dimitri Jeltsema 《International Journal of Circuit Theory and Applications》2020,48(2):254-265
It is shown that virtually all nonlinear and/or time-varying loads that generate harmonic current distortion can be characterized in terms of so-called higher-order circuit elements. The most relevant higher-order elements exploited in this paper are the memristor, meminductor, and memcapacitor. Such elements naturally arise by introducing constitutive relationships in terms of higher-order voltage and current differentials and integrals. Consequently, the power conditioner necessary to compensate for the load current distortions is synthesized similarly. The new characterization and compensation synthesis is applied to the half-wave rectifier and the controlled bridge converter. 相似文献
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Nisha Yadav Shireesh Kumar Rai Rishikesh Pandey 《International Journal of Circuit Theory and Applications》2020,48(7):1154-1179
In this paper, grounded and floating decremental/incremental memristor emulators have been proposed by using an operational transconductance amplifier (OTA), current differencing buffered amplifier (CDBA), and a grounded capacitor. The proposed memristor emulators are simpler in design over most of the realizations of memristor emulators available in the literature. The proposed configurations of grounded and floating decremental memristor emulators can be easily converted into grounded and floating incremental memristor emulators. The pinched hysteresis loops obtained from proposed memristor emulators are maintained up to 1-MHz frequency in both decremental and incremental configurations. Simulation results have been obtained using a Mentor Graphics Eldo simulation tool in 0.18-μm complementary metal-oxide semiconductor (CMOS) technology parameters. Analog filters have also been designed to verify the performance of proposed grounded and floating memristor emulators. 相似文献
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Vinod K. Sangwan Sonal V. Rangnekar Joohoon Kang Jianan Shen Hong-Sub Lee David Lam Junhua Shen Xiaolong Liu Ana C. M. de Moraes Lidia Kuo Jie Gu Haihua Wang Mark C. Hersam 《Advanced functional materials》2021,31(52):2107385
Memristive systems present a low-power alternative to silicon-based electronics for neuromorphic and in-memory computation. 2D materials have been increasingly explored for memristive applications due to their novel biomimetic functions, ultrathin geometry for ultimate scaling limits, and potential for fabricating large-area, flexible, and printed neuromorphic devices. While the switching mechanism in memristors based on single 2D nanosheets is similar to conventional oxide memristors, the switching mechanism in nanosheet composite films is complicated by the interplay of multiple physical processes and the inaccessibility of the active area in a two-terminal vertical geometry. Here, the authors report thermally activated memristors fabricated from percolating networks of diverse solution-processed 2D semiconductors including MoS2, ReS2, WS2, and InSe. The mechanisms underlying threshold switching and negative differential resistance are elucidated by designing large-area lateral memristors that allow the direct observation of filament and dendrite formation using in situ spatially resolved optical, chemical, and thermal analyses. The high switching ratios (up to 103) that are achieved at low fields (≈4 kV cm−1) are explained by thermally assisted electrical discharge that preferentially occurs at the sharp edges of 2D nanosheets. Overall, this work establishes percolating networks of solution-processed 2D semiconductors as a platform for neuromorphic architectures. 相似文献
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《Advanced Materials Interfaces》2018,5(4)
Nanopatterned fabrication and electrical properties of Ag/Sb2Te3 layer‐by‐layer assembled films are systematically investigated by a conductive atomic force microscope. Multilayers’ film composed by alternating Ag and Sb2Te3 with respective thicknesses of 5 and 10 nm shows a bipolar resistive switching behavior contributed by the silver conductive filaments. Designed cross‐plane nanofilament arrays with reconfigurable patterns are fabricated, which show a potential application in memristor and nanofabrication. Multilayers with the same thickness of Ag but increased thickness of Sb2Te3 (up to 20 nm) present a Fowler–Nordheim tunneling‐dominated current and show in‐plane snowflake silver dendrite on the surface. Further studies on the silver dendrite may bring potential applications in extensive fields such as multifunctional data storage and neuromorphic. By controlling the type (Sb2Te3, Bi2Te3, etc.) and thickness of solid electrolyte materials, electronic devices with specific functions and applications can be designed. 相似文献