We propose an efficient hand gesture recognition (HGR) algorithm, which can cope with time-dependent data from an inertial measurement unit (IMU) sensor and support real-time learning for various ...human-machine interface (HMI) applications. Although the data extracted from IMU sensors are time-dependent, most existing HGR algorithms do not consider this characteristic, which results in the degradation of recognition performance. Because the dynamic time warping (DTW) technique considers the time-dependent characteristic of IMU sensor data, the recognition performance of DTW-based algorithms is better than that of others. However, the DTW technique requires a very complex learning algorithm, which makes it difficult to support real-time learning. To solve this issue, the proposed HGR algorithm is based on a restricted column energy (RCE) neural network, which has a very simple learning scheme in which neurons are activated when necessary. By replacing the metric calculation of the RCE neural network with DTW distance, the proposed algorithm exhibits superior recognition performance for time-dependent sensor data while supporting real-time learning. Our verification results on a field-programmable gate array (FPGA)-based test platform show that the proposed HGR algorithm can achieve a recognition accuracy of 98.6% and supports real-time learning and recognition at an operating frequency of 150 MHz.
In this letter, a new learnable binary MIMO detection algorithm in massive MIMO systems with one‐bit analog‐to‐digital converters is proposed. A negative penalty is introduced to transform a ...non‐convex constraint to a convex box constraint and a learnable iterative algorithm is presented based on inexact alternating direction methods of multipliers. The proposed MIMO detection method performs better than the existing binary MIMO detection methods even with lower computational complexity.
The letter introduces a novel binary MIMO detection algorithm for massive MIMO systems using one‐bit analog‐to‐digital converters. It employs a negative penalty to make a non‐convex constraint convex and presents a learnable iterative algorithm based on inexact alternating direction methods of multipliers. This new method outperforms existing binary MIMO detection techniques while maintaining significantly lower computational complexity.
Room‐temperature liquid metal (LM)‐based electronics is expected to bring advancements in future soft electronics owing to its conductivity, conformability, stretchability, and biocompatibility. ...However, various difficulties arise when patterning LM because of its rheological features such as fluidity and surface tension. Numerous attempts are made to overcome these difficulties, resulting in various LM‐patterning methods. An appropriate choice of patterning method based on comprehensive understanding is necessary to fully utilize the unique properties. Therefore, the authors aim to provide thorough knowledge about patterning methods and unique properties for LM‐based future soft electronics. First, essential considerations for LM‐patterning are investigated. Then, LM‐patterning methods—serial‐patterning, parallel‐patterning, intermetallic bond‐assisted patterning, and molding/microfluidic injection—are categorized and investigated. Finally, perspectives on LM‐based soft electronics with unique properties are provided. They include outstanding features of LM such as conformability, biocompatibility, permeability, restorability, and recyclability. Also, they include perspectives on future LM‐based soft electronics in various areas such as radio frequency electronics, soft robots, and heterogeneous catalyst. LM‐based soft devices are expected to permeate the daily lives if patterning methods and the aforementioned features are analyzed and utilized.
Room‐temperature liquid metal (LM)‐based electronics will bring advancements in soft electronics owing to its unique properties. However, patterning LM is difficult because of its rheological features. This resulted in various LM‐patterning methods. A choice of patterning method with understanding is necessary to utilize the properties of LM. Therefore, knowledge about patterning methods and properties for LM‐based soft electronics is provided.
We theoretically analyze an optically spin-polarized collection of atoms, which serves as a basis for atomic sensors. Assuming that the intrinsic atomic spin projection noise is negligible, we ...provide the closed-form autocorrelation function and the power spectral density (PSD) of the solution to a noisy version of an optically pumped Bloch equation, wherein each component of the external magnetic field is subjected to white noise. We conclude that noise in the bias B-field direction does not affect the autocorrelation function, up to first order in white noise covariance amplitudes. Moreover, the noise terms for the remaining two axes make different contributions to the magnetic noise-driven spin PSD; in particular, the contribution corresponding to noises perpendicular to the probing direction dominates at high frequencies. Some results concerning the second (and higher)-order terms are given. In particular, we anticipate a decrease in the effective Larmor frequency despite an increase in the magnetic field magnitude in the case of anisotropic transversal B-field noises. The analytic results are supported by Monte Carlo simulations employing the Euler–Maruyama method. The analytic methodology is applied to the case of a Bell–Bloom magnetometer, which reveals a non-linearity in the PSD of the magnetometer output and also a broadening effect due to magnetic field noise.
Recently, negative differential resistance devices have attracted considerable attention due to their folded current-voltage characteristic, which presents multiple threshold voltage values. Because ...of this remarkable property, studies associated with the negative differential resistance devices have been explored for realizing multi-valued logic applications. Here we demonstrate a negative differential resistance device based on a phosphorene/rhenium disulfide (BP/ReS
) heterojunction that is formed by type-III broken-gap band alignment, showing high peak-to-valley current ratio values of 4.2 and 6.9 at room temperature and 180 K, respectively. Also, the carrier transport mechanism of the BP/ReS
negative differential resistance device is investigated in detail by analysing the tunnelling and diffusion currents at various temperatures with the proposed analytic negative differential resistance device model. Finally, we demonstrate a ternary inverter as a multi-valued logic application. This study of a two-dimensional material heterojunction is a step forward toward future multi-valued logic device research.
A high‐performance ReS2‐based thin‐film transistor and photodetector with high on/off‐current ratio (104), high mobility (7.6 cm2 V−1 s−1), high photoresponsivity (2.5 × 107 A W−1), and fast temporal ...response (rising and decaying time of 670 ms and 5.6 s, respectively) through O2 plasma treatment is reported.
Abstract
tRNA-derived RNA fragments (tRFs) have emerged as a new class of functional RNAs implicated in cancer, metabolic and neurological disorders, and viral infection. Yet our understanding of ...their biogenesis and functions remains limited. In the present study, through analysis of small RNA profile we have identified a distinct set of tRFs derived from pre-tRNA 3′ trailers in the hepatocellular carcinoma cell line Huh7. Among those tRFs, tRF_U3_1, which is a 19-nucleotide-long chr10.tRNA2-Ser(TGA)-derived trailer, was expressed most abundantly in both Huh7 and cancerous liver tissues, being present primarily in the cytoplasm. We show that genetic loss of tRF_U3_1 does not affect cell growth and it is not involved in Ago2-mediated gene silencing. Using La/SSB knockout Huh7 cell lines, we demonstrate that this nuclear-cytoplasmic shuttling protein directly binds to the 3′ U-tail of tRF_U3_1 and other abundantly expressed trailers and plays a critical role in their stable cytoplasmic accumulation. The pre-tRNA trailer-derived tRFs capable of sequestering the limiting amounts of La/SSB in the cytoplasm rendered cells resistant to various RNA viruses, which usurp La/SSB with RNA chaperone activity for their gene expression. Collectively, our results establish the trailer-derived tRF-La/SSB interface, regulating viral gene expression.
Direct chemical vapor deposition (CVD) growth of single‐layer graphene on CVD‐grown hexagonal boron nitride (h‐BN) film can suggest a large‐scale and high‐quality graphene/h‐BN film hybrid structure ...with a defect‐free interface. This sequentially grown graphene/h‐BN film shows better electronic properties than that of graphene/SiO2 or graphene transferred on h‐BN film, and suggests a new promising template for graphene device fabrication.
Bone mineral content (BMC) values in certain bones and changes in BMC over time are key features for diagnosing osteoporosis. This study examined those features using morphometric texture analysis in ...chest computational tomography (CT) by comparing a dual-energy X-ray absorptiometry (DXA)-based BMC. An accessible approach for screening osteoporosis was suggested by accessing BMC using only Hounsfield units (HU).
The study included a total of 510 cases (255 patients) acquired between May 6, 2012, and June 30, 2020, at a single institution. Two cases were associated with two chest CT scans from one patient with a scan interval of over two years, and each scan was followed soon after by a DXA scan. Axial cuts of the first lumbar vertebra in CT and DXA-based L1 BMC values were corrected for each case. The maximum trabecular area was selected from the L1 spine body, and 45 texture features were extracted from the region using gray-level co-occurrence matrices. A regression model was employed to estimate the absolute BMC value in each case using 45 features. Also, an additional regression model was used to estimate the change in BMC between two scans for each patient using 90 features from the corresponding cases.
The correlation coefficient (CC) and mean absolute error (MAE) between estimates and DXA references were obtained for the evaluation of regressors. In the case of the BMC estimation, CC and MAE were 0.754 and 1.641 (g). In the case of the estimation of change in BMC, CC and MAE were 0.680 and 0.528 (g).
The modality using morphometric texture analysis with CT HUs can indirectly help screening osteoporosis because it provides estimates of BMC and BMC change that show moderate positive correlations with DXA measures.
For over two decades photoacoustic imaging has been tested clinically, but successful human trials have been limited. To enable quantitative clinical spectroscopy, the fundamental issues of ...wavelength-dependent fluence variations and inter-wavelength motion must be overcome. Here we propose a real-time, spectroscopic photoacoustic/ultrasound (PAUS) imaging approach using a compact, 1-kHz rate wavelength-tunable laser. Instead of illuminating tissue over a large area, the fiber-optic delivery system surrounding an US array sequentially scans a narrow laser beam, with partial PA image reconstruction for each laser pulse. The final image is then formed by coherently summing partial images. This scheme enables (i) automatic compensation for wavelength-dependent fluence variations in spectroscopic PA imaging and (ii) motion correction of spectroscopic PA frames using US speckle tracking in real-time systems. The 50-Hz video rate PAUS system is demonstrated in vivo using a murine model of labelled drug delivery.
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