757 research outputs found

    The web - based tool for identification of amphibian and reptiles presented in three western provinces of South - Eastern region, Vietnam

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    Based on checklist, the keys to the identification updating with the new name of species according to Sang Nguyen Van et al author of the book ā€œHerpetofauna of Vietnamā€ publisher Chimaira published in 2009 and the biological and ecological data of 120 species of amphibian and reptiles known from the herpetofauna in three western provinces of South - Eastern region, South Vietnam was announced by Hoa Pham Van in 2005 to build the web-based tool for identification of species from this herpetofaunayesBelgorod State Universit

    Influence of heterostructure on structure, electric and magnetic properties of Bi<sub>0.5</sub>(Na<sub>0.80</sub>,K<sub>0.20</sub>)<sub>0.5</sub>TiO<sub>3</sub>/BaZrO<sub>3</sub> films prepared by the sol-gel method

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    This study reports on the structure, electric, and magnetic properties of Bi0.5(Na0.80,K0.20)0.5TiO3/BaZrO3 (BNKT/BZO) heterolayered films synthesized via chemical solution deposition on Pt/Ti/SiO2/Si substrates. The influence of different heterolayered configurations on the microstructure, electric and magnetic properties of the films was investigated thoroughly. The heterostructures are expected to generate strongly correlated electron systems in the BNKT and BZO layers that cause a magnetic interface effect in the BNKT/BZO conjunction layer. The BZO layer also prevents metal ion evaporation, resulting in a decline in oxygen vacancies and an enhancement in the electric and magnetic properties. The obtained results show that magnetic properties and leakage current density (J) of BNKT/BZO heterolayered films were greatly improved thanks to the heterolayered structure. Heterolayered 4BNKT/2BZO films (M42) yield the highest M s and M r values of 14.4 emu cmāˆ’3 and 1.7 emu cmāˆ’3, respectively, about three times higher than multilayered BNKT. Thanks to heterolayered structure, J decreases strongly from 16.0 Ɨ 10āˆ’4 A cmāˆ’2 for BNKT films to 1.4 Ɨ 10āˆ’4 A cmāˆ’2 for heterolayered M42 films. It has been verified that the leakage current in BNKT/BZO heterolayered films follows the Schottky barrier mechanism, with the barrier height fluctuating between 0.80 eV and 0.92 eV. The results of the study show that BNKT/BZO heterolayered films may be suitable for use in environmentally friendly multifunction devices.</p

    DNA barcoding for identification of some fish species (Carangidae) in Vietnam coastal area

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    Carangidae family has got about 148 species belonging to 32 genera. In Vietnam, Carangidae is of high commercial value and playing an important role in the ecosystem. In the context Vietnam has received yellow card for seafood since Nov. 2017 by the EU, in which one of the main reasons was related to the restriction of traceability. In this study, DNA barcoding technique of mitochondrial cytochrome oxidase I (COI) gene was used to classify 56 specimens of Carangidae from three coastal areas (Northern, Central and Southern) in Vietnam to evaluate the effectiveness compared to the morphological classification method. Results showed that 21 species belonging to 16 genera were determined by the COI barcode while 18 species (16 genera) were determined when using morphological method. Seriola quinqueradiata and Trachinotus anak were newly recorded in Vietnam. From 56 sequences with 660 bp of mtDNA (COI), total 27 haplotypes were detected; haplotype diversity (h) and nucleotide diversity (Ļ€) were 0.903 Ā± 0.00060 and 0.14%, respectively. The DNA barcodes of COI gene of 21 species in Carangidae which were developed in this study could be used as a basis for comparison and traceability of their products. In addition, the results showed the high potentiality in using COI barcode to identify Carangidae fish in Vietnam

    LAPFormer: A Light and Accurate Polyp Segmentation Transformer

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    Polyp segmentation is still known as a difficult problem due to the large variety of polyp shapes, scanning and labeling modalities. This prevents deep learning model to generalize well on unseen data. However, Transformer-based approach recently has achieved some remarkable results on performance with the ability of extracting global context better than CNN-based architecture and yet lead to better generalization. To leverage this strength of Transformer, we propose a new model with encoder-decoder architecture named LAPFormer, which uses a hierarchical Transformer encoder to better extract global feature and combine with our novel CNN (Convolutional Neural Network) decoder for capturing local appearance of the polyps. Our proposed decoder contains a progressive feature fusion module designed for fusing feature from upper scales and lower scales and enable multi-scale features to be more correlative. Besides, we also use feature refinement module and feature selection module for processing feature. We test our model on five popular benchmark datasets for polyp segmentation, including Kvasir, CVC-Clinic DB, CVC-ColonDB, CVC-T, and ETIS-LaribComment: 7 pages, 7 figures, ACL 2023 underrevie

    Invited review. Bond dissociation enthalpies in benzene derivatives and effect of substituents: an overview of density functional theory (B3LYP) based computational approach

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    In this review, we have mainly focused on the recent computational studies on the bond dissociation enthalpies (BDE) of the Xā€’H bonds of the para and meta substituted benzene derivatives (3Y-C6H4Xā€’H and 4Y-C6H4Xā€’H with X = O, S, Se, NH, PH, CH2, SiH2 and Y = H, F, Cl, CH3, OCH3, NH2, CF3, CN, NO2). In addition, the remote substituent effects on the BDE(Xā€’H), the radical stability and parent one have also been discussed in terms of the calculated ground state effect, radical effect and total effect. Model chemistry of ROB3LYP/6-311++G(d,p)//B3LYP/6-311G(d,p) can reproduce the BDE values with the accuracy of 1.0ā€’2.0 kcal/mol. The good linear correlations between Hammett constants and BDE values were discovered for both para and meta substitutions in phenols, thiophenols, benzeneselenols, anilines and phenylposphines with the R-squared lager than 0.94. In contrast, it does not occur in case of toluenes and phenylsilanes.Keywords. Benzene derivatives, density functional theory, bond dissociation enthalpies, substituent effects, radical effect, ground state effect, total effect, Hammett constants

    XGV-BERT: Leveraging Contextualized Language Model and Graph Neural Network for Efficient Software Vulnerability Detection

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    With the advancement of deep learning (DL) in various fields, there are many attempts to reveal software vulnerabilities by data-driven approach. Nonetheless, such existing works lack the effective representation that can retain the non-sequential semantic characteristics and contextual relationship of source code attributes. Hence, in this work, we propose XGV-BERT, a framework that combines the pre-trained CodeBERT model and Graph Neural Network (GCN) to detect software vulnerabilities. By jointly training the CodeBERT and GCN modules within XGV-BERT, the proposed model leverages the advantages of large-scale pre-training, harnessing vast raw data, and transfer learning by learning representations for training data through graph convolution. The research results demonstrate that the XGV-BERT method significantly improves vulnerability detection accuracy compared to two existing methods such as VulDeePecker and SySeVR. For the VulDeePecker dataset, XGV-BERT achieves an impressive F1-score of 97.5%, significantly outperforming VulDeePecker, which achieved an F1-score of 78.3%. Again, with the SySeVR dataset, XGV-BERT achieves an F1-score of 95.5%, surpassing the results of SySeVR with an F1-score of 83.5%

    Advanced Method for Motion Control of a 3 DOFs Lower Limb Rehabilitation Robot

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    This paper presents two motion control methods for a lower limb rehabilitation robot based on compensate gravity proportional-derivative and inverse dynamic proportional-derivative (PD) control algorithms. The Robotā€™s mechanism is comprised of three active joints: hip joint, knee joint and ankle joint, which are driven by DC motors. Firstly, based on Robotā€™s mechanism, a dynamic model of the Robot is built. Then, based on Robotā€™s model, motion control systems for Robot are designed. Simulation results show good performances and workability of these proposed controllers. Finally, the calculation of the joint angle errors and toque of each controller is performed. The comparison of simulation results between proposed controllers and the adaptive fuzzy controller allows to choice suitable motion control methods for Robot that can meet the requirements of a 3 DOFs lower limb rehabilitation robot for post-stroke patient

    EFL Learnersā€™ Perception of Class Point Tool Application in Enhancing their Satisfaction and Active Learning in Classroom

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    Attaching the Classroom Response System (CRS) to the teaching process has been a flowering trend recently thanks to its appeal to studentsā€™ satisfaction and active learning. This paper set out simply to determine the learnersā€™ perception of the Class Point tool ā€“ a modern CRS that was launched in 2015 and has not yet been familiar to Vietnamese educators. After nine times applying the Class Point tool directly in the classrooms, the teachers, also the researchers, conducted an online survey and a semi-structured interview with over two hundred learners from four different EFL English classes at a private institution in Ho Chi Minh City. Far from the expectation, the result of this study proved that participants not only experienced pleasure with the tool but also felt effectively engaged in interactive activities. Furthermore, its modernized features seem to maximize the dominance and minimize the hardship that other CRSs still entail. The finding of this study will enable teachers to further apply the tool in their classroom with a certain view of its benefits

    EVALUATION OF BIODEGRADATION RATE CONSTANT (Kā‚) AND BOD POLLUTION IN THE LAKE SYSTEM OF HANOI

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    Joint Research on Environmental Science and Technology for the Eart
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