155 research outputs found
How to Support Poor Vietnamese Consumers to Deal with Food Price Volatility and Food Safety Issues
With 66 per cent of the population living in rural areas, over half depending on farm activities, food security and food safety are now two sides of the government effort to ensure food accessibility for the poor in Vietnam. While people living on low incomes may have to choose cheaper food over safer food, they are now more aware of food safety issues, and need more support to access safe food. After a long time of focusing on increasing food security in terms of quantities, new efforts are now needed to change the practice and awareness of stakeholders to move to quality?oriented production and consumption, including creating reasonable incentives for food producers, socialising of food safety monitoring and improving food safety inspection in Vietnam
The Transition in Goods Export Structure in the Northeast Region of Vietnam
The period 2005-2015 is an important stage in the preparation process of bringing Vietnam to basically become an industrialized country by 2020. The economic development of the Northeast with an open and export-oriented economy requires an important role of export activities in the region's socio-economic development. Although it is affected by the global economic crisis, the export value of the region has increased significantly, the structure of exports over the years has positively changed. In more detailed, the rate of raw goods slightly reduced. However, the restructuring of the region's exports has not made a breakthrough and failed to create a suitable structure of export products and made full use of the region’s advantages and potentials. The slow change of exports structure will lead to resource depletion, ecological imbalance, and poor economic efficiency. Keywords: Structure restructuring, Import and export, Northeast of Vietnam, PRODY, export commodities
An adaptive hierarchical sliding mode controller for autonomous underwater vehicles
The paper addresses a problem of efficiently controlling an autonomous underwater vehicle (AUV), where its typical underactuated model is considered. Due to critical uncertainties and nonlinearities in the system caused by unavoidable external disturbances such as ocean currents when it operates, it is paramount to robustly maintain motions of the vehicle over time as expected. Therefore, it is proposed to employ the hierarchical sliding mode control technique to design the closed-loop control scheme for the device. However, exactly determining parameters of the AUV control system is impractical since its nonlinearities and external disturbances can vary those parameters over time. Thus, it is proposed to exploit neural networks to develop an adaptive learning mechanism that allows the system to learn its parameters adaptively. More importantly, stability of the AUV system controlled by the proposed approach is theoretically proved to be guaranteed by the use of the Lyapunov theory. Effectiveness of the proposed control scheme was verified by the experiments implemented in a synthetic environment, where the obtained results are highly promising. © 2021 by the authors. Licensee MDPI, Basel, Switzerland. **Please note that there are multiple authors for this article therefore only the name of the first 5 including Federation University Australia affiliate “Linh Nguyen" is provided in this record*
EVALUATION OF ACUTE AND SUB-ACUTE ORAL TOXICITY OF CLINACANTHUS NUTANS LEAVES EXTRACT IN MICE
Objective: This study aimed to evaluate acute and sub-acute oral toxicity of ethanol extract of Clinacanthus nutans leaves in Swiss mice.
Methods: Acute oral toxicity study was performed as per OECD-423 guidelines. Sub-acute oral toxicity study was performed as per OECD-407 guidelines. The extract was dissolved in 10% dimethyl sulfoxide and administered orally, while the control group received only the vehicle.
Results: The acute oral toxicity test on mice showed that this extract was well tolerated up to LD50 5000 mg/kg body weight/day oral dosage level and non-toxic to mice under the present experimental conditions. The sub-acute toxicity study was carried out on mice with the oral dosage of the extract from 100 mg/kg–500 mg/kg body weight/day and 5000 mg/kg body weight/day for 28 d. The results showed that this extract did not induce death or adverse effects in activity, feed consumption or body weight gain. There were not significant changes in heamotological and biochemical parameters between control and experiment groups.
Conclusion: Thus, Clinacanthus nutans leaf has a very low toxicity value
A Two-Bit Reflectarray Element Using Cut-Ring Patch Coupled to Delay Lines
In this paper, a two-bit element for reflectarray applications is presented. The proposed element is based on the cut-ring patch coupled to delay lines through an annular slot. The four states of the reflection phase with a step of 90◦ are achieved with two switches. This reported work is the first step towards the 2-bit active reflectarray element. Prototypes of the element have been fabricated and characterized in X-band using waveguide simulator. Measured results show good characteristics with low magnitude losses and the bandwidth of 1.7-bit resolution is over 5%
Deep Transfer Learning: A Novel Collaborative Learning Model for Cyberattack Detection Systems in IoT Networks
Federated Learning (FL) has recently become an effective approach for
cyberattack detection systems, especially in Internet-of-Things (IoT) networks.
By distributing the learning process across IoT gateways, FL can improve
learning efficiency, reduce communication overheads and enhance privacy for
cyberattack detection systems. Challenges in implementation of FL in such
systems include unavailability of labeled data and dissimilarity of data
features in different IoT networks. In this paper, we propose a novel
collaborative learning framework that leverages Transfer Learning (TL) to
overcome these challenges. Particularly, we develop a novel collaborative
learning approach that enables a target network with unlabeled data to
effectively and quickly learn knowledge from a source network that possesses
abundant labeled data. It is important that the state-of-the-art studies
require the participated datasets of networks to have the same features, thus
limiting the efficiency, flexibility as well as scalability of intrusion
detection systems. However, our proposed framework can address these problems
by exchanging the learning knowledge among various deep learning models, even
when their datasets have different features. Extensive experiments on recent
real-world cybersecurity datasets show that the proposed framework can improve
more than 40% as compared to the state-of-the-art deep learning based
approaches.Comment: 12 page
All-dielectric Metamaterial for Electromagnetically-induced Transparency in Optical Region
Metamaterial (MM) is emerging as a promising approach to manipulate electromagnetic waves, spanning from radio frequency to the optical region. In this paper, we employ an effect called electromagnetically-induced transparency (EIT) in all-dielectric MM structures to create a narrow transparent window in opaque broadband of the optical region (580-670 nm). Using dielectric materials instead of metals can mitigate the large non-radiative ohmic loss on the metal surface. The unit-cell of MM consists of Silicon (Si) bars on Silicon dioxide (SiO) substrate, in which two bars are directed horizontally and one bar is directed vertically. By changing the relative position and dimension of the Si bars, the EIT effect could be achieved. The optical properties of the proposed MM are investigated numerically using the finite difference method with commercial software Computer Simulation Technology (CST). Then, characteristic parameters of MM exhibiting EIT effect (EIT-MM), including Q-factor, group delay, are calculated to evaluate the applicability of EIT-MM to sensing and light confinement
Antibiotic Resistance Profile and Methicillin-Resistant Encoding Genes of Staphylococcus aureus Strains Isolated from Bloodstream Infection Patients in Northern Vietnam
Background: Evaluating the antibiotic susceptibility and resistance genes is essential in the clinical management of bloodstream infections (BSIs). Nevertheless, there are still limited studies in Northern Vietnam.
AIM: This study aimed to determine the antibiotic resistance profile and methicillin-resistant encoding genes of Staphylococcus aureus (S. aureus) causing BSIs in Northern Vietnam.
METHODS: The cross-sectional study was done from December 2012 to June 2014 in two tertiary hospitals in Northern Vietnam. Tests performed at the lab of the hospital.
RESULTS: In 43 S. aureus strains isolating, 53.5 % were MRSA. Distribution of gene for overall, MRSA, and MSSA strains were following: mecA gene (58.1 %; 95.7%, and 15%), femA gene (48.8%, 47.8%, and 50%), femB gene (88.4%, 82.6%, and 95%). Antibiotic resistance was highest in penicillin (100%), followed by erythromycin (65.1%) and clindamycin (60.5%). Several antibiotics were susceptible (100%), including vancomycin, tigecycline, linezolid, quinupristin/dalfopristin. Quinolone group was highly sensitive, include ciprofloxacin (83.7%), levofloxacin (86%) and moxifloxacin (86%).
CONCLUSION: In S. aureus causing BSIs, antibiotic resistance was higher in penicillin, erythromycin, and clindamycin. All strains were utterly susceptible to vancomycin, tigecycline, linezolid, quinupristin/dalfopristin
Antibiotic Resistance Profile and Diversity of Subtypes Genes in Escherichia coli Causing Bloodstream Infection in Northern Vietnam
BACKGROUND: Evaluating the antibiotic susceptibility and resistance genes is essential in the clinical management of bloodstream infections (BSIs). But there are still limited studies in Northern Vietnam.
AIM: The aim of the study was to determine the antibiotic resistance profile and characteristics of subtypes genes in Escherichia coli causing BSIs in Northern Vietnam.
METHODS: The cross-sectional study was done in the period from December 2012 to June 2014 in two tertiary hospitals in Northern Vietnam. Tests were performed at the lab of the hospital.
RESULTS: In 56 E. coli strains isolating 39.29 % produced ESBL. 100% of the isolates harbored blaTEM gene, but none of them had the blaPER gene. The prevalence of ESBL producers and ESBL non-producers in blaCTX-M gene was 81.82%, and 73.53%, in blaSHV gene was 18.18% and 35.29%. Sequencing results showed three blaTEM subtypes (blaTEM 1, 79, 82), four blaCTX-M subtypes (blaCTX-M-15, 73, 98, 161), and eight blaSHV subtypes (blaSHV 5, 7, 12, 15, 24, 33, 57, 77). Antibiotic resistance was higher in ampicillin (85.71%), trimethoprim/sulfamethoxazole (64.29%) and cephazolin (50%). Antibiotics were still highly susceptible including doripenem (96.43%), ertapenem (94.64%), amikacin (96.43%), and cefepime (89.29%).
CONCLUSION: In Escherichia coli causing BSIs, antibiotic resistance was higher in ampicillin, trimethoprim/sulfamethoxazole and cephazolin. Antibiotics was highly susceptible including doripenem, ertapenem, amikacin, and cefepime
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