629 research outputs found
The web - based tool for identification of amphibian and reptiles presented in three western provinces of South - Eastern region, Vietnam
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 “Herpetofauna of Vietnam” 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
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 cm−3 and 1.7 emu cm−3, respectively, about three times higher than multilayered BNKT. Thanks to heterolayered structure, J decreases strongly from 16.0 × 10−4 A cm−2 for BNKT films to 1.4 × 10−4 A cm−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
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 (π) were 0.903 ± 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
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
In this review, we have mainly focused on the recent computational studies on the bond dissociation enthalpies (BDE) of the X‒H bonds of the para and meta substituted benzene derivatives (3Y-C6H4X‒H and 4Y-C6H4X‒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(X‒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 1.0‒2.0 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
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
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 Robot’s mechanism is comprised of three active joints: hip joint, knee joint and ankle joint, which are driven by DC motors. Firstly, based on Robot’s mechanism, a dynamic model of the Robot is built. Then, based on Robot’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
EVALUATION OF BIODEGRADATION RATE CONSTANT (K₁) AND BOD POLLUTION IN THE LAKE SYSTEM OF HANOI
Joint Research on Environmental Science and Technology for the Eart
AN EVIDENCE FOR THE CONTRIBUTION OF ANAMMOX PROCESS IN NITROGEN REMOVAL FROM GROUNDWATER
Joint Research on Environmental Science and Technology for the Eart
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