Large-scale Vietnamese point-of-interest classification using weak labeling

Point-of-Interests (POIs) represent geographic location by different categories (e.g., touristic places, amenities, or shops) and play a prominent role in several location-based applications. However, the majority of POIs category labels are crowd-sourced by the community, thus often of low quality. In this paper, we introduce the first annotated dataset for the POIs categorical classification task in Vietnamese. A total of 750,000 POIs are collected from WeMap, a Vietnamese digital map. Large-scale hand-labeling is inherently time-consuming and labor-intensive, thus we have proposed a new approach using weak labeling. As a result, our dataset covers 15 categories with 275,000 weak-labeled POIs for training, and 30,000 gold-standard POIs for testing, making it the largest compared to the existing Vietnamese POIs dataset. We empirically conduct POI categorical classification experiments using a strong baseline (BERT-based fine-tuning) on our dataset and find that our approach shows high efficiency and is applicable on a large scale. The proposed baseline gives an F1 score of 90% on the test dataset, and significantly improves the accuracy of WeMap POI data by a margin of 37% (from 56 to 93%)

An Analysis of Shoreline Changes Using Combined Multitemporal Remote Sensing and Digital Evaluation Model

Cua Dai estuary belonged to Quang Nam province is considered to be one of the localities of Vietnam having a complex erosion and accretion process. In this area, sandbars are recently observed with lots of arguments about the causes and regimes of formation. This could very likely result of not reliable source of information on shoreline evolution and a lack of historical monitoring data. Accurately identification of shoreline positions over a given period of time is a key to quantitatively and accurately assessing the beach erosion and accretion. The study is therefore to propose an innovative method of accurately shoreline positions for an analysis of coastal erosion and accretion in the Cua Dai estuary. The proposed technology of multitemporal remote sensing and digital evaluation model with tidal correction are used to analyse the changes in shoreline and estimate the rate of erosion and accretion. An empirical formula is, especially, exposed to fully interpret the shoreline evolution for multiple scales based on a limitation of satellite images during 1965 to 2018. The results show that there is a significant difference of shoreline shift between corrections and non-corrections of tidal. Erosion process tends to be recorded in the Cua Dai cape located in the Cua Dai ward, especially in the An Luong cape located in the Duy Hai commune with the length of 1050 m. Furthermore, it is observed that there is much stronger erosion in the north side compared with south side of Cua Dai estuary

EFL Agreeing and Disagreeing Discourses in Facebook

Agreeing and disagreeing are two common speech acts that occur in social conversations. Driven by the fact that there are direct and indirect way for expressing agreement and disagreement, and there are also mitigating strategies to protect interlocutors from face-threatening in disagreeing discourses, this study examined EFL students’ use of discourse strategies in their Facebook interaction. Thirty-four pre-intermediate EFL students at a university in Vietnam took part in this study. Data analysis shows that direct discourses is linguistically limited while indirect ones exhibit wider language use. Students also demonstrate two different directions of using mitigating strategies for their disagreeing discourses. Some pedagogical implications are also suggested in this study. Keywords: agreeing, disagreeing, direct, indirect, strategies DOI: 10.7176/JLLL/86-03 Publication date: February 28th 202

Application of Google Docs in English for Specific Purposes Collaborative Writing

English language learners today have considerable opportunities to practice their writing skill via their peer interaction in Web 2.0 platforms, such as Blogs, Wikis, and Google Docs. Different studies have investigated the influence of these platforms on student writing collaboration and interaction, but few studies had explored factors that may affect English for Specific Purposes (ESP) student collaborative writing in Vietnamese settings. This study, therefore, attempts to explore the impact of four factors, namely gender, student attitudes towards learning English, student economic status, and availability of English at home on Google Docs-based interaction and collaborative writing outcome at a southern university in Vietnam. Fifty participants took part in this study and they worked collaboratively in small groups in Google Docs to finish two writing tasks and complete a survey afterwards. Analysis of their survey, interaction, and writing outcome suggests that gender, student attitudes towards learning English, and the number of books available at their homes have an impact on their writing outcome whereas their economic status did not seemingly affect their writing quality. Some pertinent pedagogical implications are also discussed in this paper. Keywords: Google Docs, collaborative writing, English for Specific Purposes DOI: 10.7176/JLLL/78-02 Publication date: April 30th 202

The Synthesis and Photoluminescence of 3C-SiC Nanorods

The 3C-SiC nanorods were grown by using carbothermal reduction of SiO$_{2}$ without any catalyst. The intensive broad photoluminescence peak around 480-500 nm was observed at room temperature. The 3C-SiC nanorods with green -- blue emitting light may have great application in display devices and light emitting diodes

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

INFLUENCING FACTORS TO LOGISTICS CENTRE FORMATION – A STUDY OF VIETNAM-BASED LOGISTICS SECTOR

Purpose of the study: The paper tries to model dynamic interactions of factors that contribute to the logistics center building. Conducting the desk review and expert consultation, the causality of the factors is systemized in a form of Causal Loop Diagram using the System Dynamics approach. Methodology: System Dynamics (SD) is an approach for studying interlinked behaviors within a system and reflects the interactions of feedback loops. Compared to other approaches, SD demonstrates the real world by using factors and stocks for components and feedback loops for inter-relationships among them. SD model qualitatively illustrates the causal relationship among factors that influence the building of the logistics center. Main Findings: A combination of four different sub-systems, using a questionnaire survey conducted with logistics service users and providers to sort out the high scored factors. Besides, the survey also helps to study the practical conditions and characteristics in showing the demand, the trend, and the development of logistics centers in Vietnam. Applications of this study: Logistics centers (LCs) can be considered as a depot for vehicles where drivers and managers of vehicles are supposed to maintain, repair vehicles, and adjust vehicle operation schedules. Novelty/Originality of this study: As defined by the scope of the project, the SD model provides a qualitative demonstration of the interaction among factors. The built model gives a systematic insight into how factors link to each other

Epidemiological and molecular characteristics of Infectious bursal disease virus naturally infected in the broiler flocks in the Mekong Delta of Vietnam during 2015 and 2018

Infectious bursal disease is a highly contagious and economically devastating disease in the poultry industry worldwide caused by Infectious bursal disease virus (IBDV). However, the data on epidemiological and molecular characteristics of the IBDV outbreak in broiler flocks in the Mekong Delta of Vietnam is unclear. Herein, the epidemiological data of IBDV–positive flocks over a period of 2015–2018 were recorded and the hypervariable region of the VP2 gene of IBDV was amplified to analyze the local phylogeny. The current investigation showed that the overall morbidity and mortality rates of IBDV–positive flocks were 45% and 4.81%, respectively. The IBDV–positive birds occurred clinical signs and macroscopic findings involved with the very virulent (vv) IBDV outbreak. Epidemiological results revealed that IBDV was frequently infected in broiler flocks at 12–42 days, and birds belonging to Tau Vang and Binh Dinh breeds were more sensitive to IBDV. Also, the morbidity rate of IBDV was dramatically decreased in the open farming system. Flocks with complete vaccination significantly dropped morbidity in comparison with other groups. Regarding phylogenetic analysis, all identified IBDV sequences clustered in the same branch of vv phenotype and closely homology with prior strains circulated in Vietnam and other countries. These findings first indicated the epidemiological characteristics of the IBDV–positive broiler flocks in the Mekong Delta and highlighted the IBDV strain circulating in this region

Simulation of the Heavy Charged Particle Impacts on Electrical Characteristics of N-MOSFET Device Structure

The paper presents the results of simulation of the impacts of a heavy charged particle with a value of linear energy transfer equal to 1.81 MeV•cm2 /mg, 10.1 MeV•cm2 /mg, 18.8 MeV•cm2 /mg, 55.0 MeV•cm2 /mg, corresponding to nitrogen ions 15N+4 with energy E = 1.87 MeV, argon 40Ar+12 with energy E = 372 MeV, ferrum 56Fe+15 with energy E = 523 MeV, xenon 131Xe+35 with energy E = 1217 MeV, on electrical characteristics of n-MOSFET device structure when there are variations in the motion trajectory and ambient temperature