120 research outputs found
A Vietnamese Handwritten Text Recognition Pipeline for Tetanus Medical Records
Machine learning techniques are successful for optical character recognition tasks, especially in recognizing handwriting. However, recognizing Vietnamese handwriting is challenging with the presence of extra six distinctive tonal symbols and vowels. Such a challenge is amplified given the handwriting of health workers in an emergency care setting, where staff is under constant pressure to record the well-being of patients. In this study, we aim to digitize the handwriting of Vietnamese health workers. We develop a complete handwritten text recognition pipeline that receives scanned documents, detects, and enhances the handwriting text areas of interest, transcribes the images into computer text, and finally auto-corrects invalid words and terms to achieve high accuracy. From experiments with medical documents written by 30 doctors and nurses from the Tetanus Emergency Care unit at the Hospital for Tropical Diseases, we obtain promising results of 2% and 12% for Character Error Rate and Word Error Rate, respectively
HierarchyNet : learning to summarize source code with heterogeneous representations
Code representation is important to machine learning models in the code-related applications. Existing code summarization approaches primarily leverage Abstract Syntax Trees (ASTs) and sequential information from source code to generate code summaries while often overlooking the critical consideration of the interplay of dependencies among code elements and code hierarchy. However, effective summarization necessitates a holistic analysis of code snippets from three distinct aspects: lexical, syntactic, and semantic information. In this paper, we propose a novel code summarization approach utilizing Heterogeneous Code Representations (HCRs) and our specially designed HierarchyNet. HCRs adeptly capture essential code features at lexical, syntactic, and semantic levels within a hierarchical structure. HierarchyNet processes each layer of the HCR separately, employing a Heterogeneous Graph Transformer, a Tree-based CNN, and a Transformer Encoder. In addition, HierarchyNet demonstrates superior performance compared to fine-tuned pre-trained models, including CodeT5, and CodeBERT, as well as large language models that employ zero/few-shot settings, such as CodeLlama, StarCoder, and CodeGen. Implementation details can be found at https://github.com/FSoft-AI4Code/HierarchyNet
Security-reliability analysis in CR-NOMA IoT network under I/Q imbalance
This paper presents a controllable analysis framework for evaluating the reliability and security
of underlay cognitive radio networks (CRs) relying on non-orthogonal multiple access (NOMA). In such
systems, a secondary base station (BS) transmits confidential information to multiple secondary users
uniformly distributed in the presence of a nearby located external eavesdropper. Moreover, transmit power
constraints are introduced to limit the interference to the primary imposed by cognitive base stations. As an
effective approach of multiple input single output (MISO) systems, the transmit antenna selection (TAS)
is selected in the BS to improve the secrecy performance of the primary networks. Furthermore, we first
consider the impact of quadrature-phase imbalance (IQI) to characterize the secure performance of the
considered network in practice. Then, the degraded performance is evaluated in terms of outage probability
(OP), intercept probability (IP), and effective secrecy throughput (EST) of two NOMA users. The optimal
EST can be achieved through simulations while the results of OP and IP provide guidelines in the design of
IQI-aware CR-NOMA systems. Finally, the trade-off between OP and IP with transmit signal-to-noise ratio
(SNR) at the BS is investigated for reflecting the security characteristic. Finally, the trade-off between OP
and IP with transmit signal-to-noise ratio (SNR) at the BS is studied for displaying the security characteristic.
Numerical results show that increasing the number of transmit antennas at the BS and other main parameters
improves performance. Moreover, when the system parameters are reasonably set, the secondary NOMA
user in CR-NOMA can be reached secure requirements regardless of the controlled IQI.Web of Science1111905611904
Optical properties of MoSe monolayer implanted with ultra-low energy Cr ions
The paper explores the optical properties of an exfoliated MoSe monolayer
implanted with Cr ions, accelerated to 25 eV. Photoluminescence of the
implanted MoSe reveals an emission line from Cr-related defects that is
present only under weak electron doping. Unlike band-to-band transition, the
Cr-introduced emission is characterised by non-zero activation energy, long
lifetimes, and weak response to the magnetic field. To rationalise the
experimental results and get insights into the atomic structure of the defects,
we modelled the Cr-ion irradiation process using ab-initio molecular dynamics
simulations followed by the electronic structure calculations of the system
with defects. The experimental and theoretical results suggest that the
recombination of electrons on the acceptors, which could be introduced by the
Cr implantation-induced defects, with the valence band holes is the most likely
origin of the low energy emission. Our results demonstrate the potential of
low-energy ion implantation as a tool to tailor the properties of 2D materials
by doping
Outage analysis of the power splitting based underlay cooperative cognitive radio networks
In the present paper, we investigate the performance of the simultaneous wireless information and power transfer (SWIPT) based cooperative cognitive radio networks (CCRNs). In particular, the outage probability is derived in the closed-form expressions under the opportunistic partial relay selection. Different from the conventional CRNs in which the transmit power of the secondary transmitters count merely on the aggregate interference measured on the primary networks, the transmit power of the SWIPT-enabled transmitters is also constrained by the harvested energy. As a result, the mathematical framework involves more correlated random variables and, thus, is of higher complexity. Monte Carlo simulations are given to corroborate the accuracy of the mathematical analysis and to shed light on the behavior of the OP with respect to several important parameters, e.g., the transmit power and the number of relays. Our findings illustrate that increasing the transmit power and/or the number of relays is beneficial for the outage probability.Web of Science2122art. no. 765
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