CTU Journal of Science

Research solutions for building the embankments to cope with sea shore erosion risk at Hiep Thanh in Duyen Hai town in Tra Vinh Province

Van Huu Hue*, Le Van Tuan

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This article presents the research purpose of finding the causes of erosions and proposing solutions to coastal erosions in Hiep Thanh, Duyen Hai town, Tra Vinh province. The research method surveys and evaluates geology, impacts due to ocean waves, transports sediment through Mike 21, Plaxis, Geoslope software and presents research results. The results concluded that the leading cause of erosions is large waves impacting the coast during the northeast wind season, causing mud and sand to be blown away. Coastal currents carry mud and sand away, causing the coast to lower, causing erosions, etc. Thereby, construction solutions and new research direction for the research area were given to ensure the welfare of people in the research area.

Prediction of mangoes’ sweetness based on spectral data acquired from a low-cost multispectral sensor

Nguyen Phuoc Loc, Duong Van Su, Tran Nhut Thanh, Nguyen Chi Ngon, Nguyen Chanh Nghiem*

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Recent studies have shown that low-cost multispectral sensors have attracted much interest in developing agricultural applications. This study evaluated the potential of using a low-cost multispectral sensor to predict the sweetness of mango fruit with high export values. A few spectral data preprocessing and wavelength selection algorithms were applied to develop an accurate prediction model. Experimental results showed that unprocessed spectral data of fourteen wavelengths selected by the “regression coefficients” algorithm were suitable for developing a partial least square regression model with a correlation coefficient of 0.703 and a root mean square error of 1.439 °Brix. These results were comparable to recent studies using the same multispectral sensor, confirming the potential use of low-cost multispectral sensors in developing applications and portable devices for fruit quality assessment.

Canxi alginate-based linkage For composite films and bioleather applications: a critical review

Nguyen Ngoc Nhu Y, Nguyen Thanh Phuong*, Ta Huu Nhan, Lu Tran Tu MY, Pham Thi Ngoc Nga

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Calcium alginate gel has been widely used in composite films with many versatile applications discovered by many scientists. Besides, the trend of using environmentally friendly leather materials has developed globally. This paper reviews information about alginate-based films and eco-friendly bio-leather, which have been synthesized based on the ion-gel linking of Calcium Alginate in aqueous solution.

Detecting and displaying 3D abnormal areas on MRI images with service BILLOW AISA

Le Minh Loi, Tran Nguyen Minh Thu*, Nguyen Thien Hung, Ho Quoc An, Pham Nguyen Khang

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Timely detection of tumors to support doctors in effectively diagnosing and treating patients in overloaded hospitals is essential. The Slicer application allows the rendering of 2D images of damaged areas into 3D volume data, helping doctors obtain a more intuitive view of diagnosis and treatment. However, the Slicer application does not yet allow automatic detection of abnormal regions and requires a powerful computer to execute these models. In this research, Slicer's Billow AISA extension is proposed to build an analysis and prediction service portal from image data provided by users. The analysis and prediction function experimented in this research is the detection of abnormal areas on brain MRI images using the Swin-Unet model. Experimental results on the dataset collected from Can Tho University of Medicine and Pharmacy Hospital demonstrate the feasibility and effectiveness of the Billow AISA model.

Chlorination of MOF material based on 2-aminobenzene-1,4-dicarboxylic acid linker

Ly Thanh Dong, Tran Trang-Anh N., Tran Bich-Huyen T., Tran Bich Thuan, Nguyen Mong Hoang, Nguyen Thi Tuyet Nhung*

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In this study, a metal-organic framework based on [Zr6O4(OH)4] cluster, termed Zr‑MOF-NH2, was synthesized by the reaction of zirconium chloride (ZrCl4) and 2‑aminobenzene‑1,4‑dicarboxylic acid linker (H2BDC-NH2) in N,N¢‑dimethylformamide (DMF) and formic acid (HCOOH) by solvothermal synthesis. The structure of the resulting material was characterized by powder X‑ray diffraction (PXRD) and fourier‑transform infrared spectroscopy (FT-IR). The morphology of the compound was observed by scanning electronic microscopy (SEM) and the elemental composition was determined by energy dispersion X‑ray spectroscopy (EDS). The Zr‑MOF‑NH2 was further chlorinated with 1% NaDCC solution forming the resulting material Zr‑MOF‑NHCl. The chlorine loading on the material was quantified by the iodometric/thiosulfate titration method.

Investigation of the antioxidant, anti-inflammatory and antibacterial activities of Alternanthera sessilis

Phan Kim Dinh, Thanh Thai Vang, Hoang Duy To, Tram Anh Do, Tran Chi Linh*

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The present study was carried out to determine the phytochemistry and biological activity of extracts from the above-ground parts (stems and leaves), and the leaves and stems of Alternanthera sessilis. Antioxidant activity is determined based on neutralising or inhibiting abiotic free radicals. Anti-inflammatory activity was determined based on its ability to protect red blood cell membranes and inhibit bovine serum albumin denaturation. The antibacterial activity was determined by determining the antibacterial ring diameter, the minimum inhibitory concentration and the minimum bactericidal concentration. Alternanthera sessilis extracts have antioxidant and anti-inflammatory activities with EC50 values ranging from 50.60±0.29 to 125.58±7.12 µg/mL. Alternanthera sessilis extracts have the ability to inhibit Gram-positive bacteria more effectively than Gram-negative bacteria with minimum bactericidal concentrations ranging from 250 to 2,000 µg/mL. The antioxidant, anti-inflammatory and antibacterial activities of Alternanthera sessilis extracts are related to the polyphenols, flavonoids and alkaloids content. These results highlighted the potential use of Alternanthera sessilis extracts as a natural antioxidant, anti-inflammatory and antimicrobial agent.

The reverse scheduling-location problem with maximum lateness on trees

Le Minh Huy*, Tran Thanh Hiep

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We address the problem of finding the location of a machine on trees and scheduling jobs (located at vertices) so that the maximum lateness is minimized. The customers (jobs) move to the machine whenever they are called due to the slackness of space for jobs waiting at the machine location. We develop an algorithm that solves the corresponding problem in O(n2) time, where n is the number of vertices in the tree. On the counterpart, we investigate the problem of reducing edge lengths within a given budget to improve the maximum lateness at a prespecified point as much as possible. We call it the reverse scheduling location problem with maximum lateness on trees. A greedy-type algorithm that solved the problem in quadratic time is discussed.

Synthesis of Zr-MOF for catalyst degradation of Polyethylene Terephtalate

Nguyen Bui Thi Que Tran, Nguyen Minh Thy, Nguyen Hai Hieu, Nguyen Phuong Duy, Diep Le Ha Tho, Nguyen Thi Tuyet Nhung*

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In this study, a zirconium-based metal-organic framework (Zr-MOF) was successfully synthesized using zirconium tetrachloride (ZrCl₄) and terephthalic acid (H₂BDC) as precursors in N,N-dimethylformamide (DMF) at 120°C. The crystalline structure of the material was characterized by powder X-ray diffraction (PXRD), while its morphology was examined using field emission scanning electron microscopy (FE-SEM). Elemental composition analysis was conducted via X-ray energy dispersive spectroscopy (EDS). The synthesized Zr-MOF exhibited high thermal stability, as determined by thermogravimetric analysis (TGA). Additionally, the material demonstrated catalytic activity in the decomposition of polyethylene terephthalate (PET) into terephthalic acid (TA) within 24 hours at 260°C.

Estimating the parameters of Logistic regression with covariates missing at random and application

Tran Phuoc Loc*, Ta Thi Thanh Thuy, Duong Thi Tuyen, Duong Thi Be Ba, Le Hoai Nhan, Lam Hoang Chuong

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This study proposes a method to estimate the coefficients of the logistic regression model with covariates missing at random. Firstly, the multiple imputation method replaces missing values with reasonable values obtained from an empirical conditional distribution function. The estimator of the parameters of the regression model and its variance are then obtained by the corresponding estimating and equations and estimated variance formulas, respectively. The large sample properties of the estimator are also studied. The estimator efficiency of the proposed method is studied through several numerical simulation scenarios and compared with other methods. The results show that the proposed method has outperformed the other methods, e.g., complete-case, semi-parametric inverse probability weighting, validation likelihood, and random forest multiple imputation methods. Real example data from medical research is used to illustrate the applicability of the proposed method.

Conditions for coexistence of two species in the Lotka-Volterra competitive system

Le Xuan Dai, Duong Hung Manh*

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In this paper, the Lotka-Volterra system (LVS) is studied . Under some conditions of space forcing terms, the qualitative properties of equilibrium points was stated and the conditions for the coexistence of the two species of the ordinary differential equations for LVS are examined. Furthermore, the factors that influence the survival or extinction of the two species are examined and the numerical running examples are given to elucidate the theoretical results obtained through visualization of trajectory of the solution curve and the surrounding vector field balance points.

First data on species diversity and distribution of centipedes (Chilopoda) in Son Doong cave, Quang Binh province

Le Xuan Son, NGUYEN DUC HUNG, Nguyễn Đức Anh, Tran Thi Thanh Binh*

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Son Doong Cave is the largest natural cave in the world, with a length of nearly 9,000m, a height of 100m, and a width of 80-100m maintained nearly the entire length of the cave. Its large size contains many interesting geological features, notably two large and deep sinkholes, where light can shine down enough to grow a tropical forest at the bottom of the cave. From there, a very diverse ecosystem is formed with special values in many natural aspects, including biodiversity. To understand the centipedes in Son Doong cave, a field investigation in May 2022 was conduction. The results recorded 5 centipede species belonging to 4 families and 4 orders. Among them, two species have only been identified to the genus Lithobius sp. and Mecistocephalus sp.. These are the two species that dominate the number of individuals recorded. Besides, there are species widely distributed in Vietnam including Scolopendra subspinipes, Otostigmus scaber and Thereuopoda longicornis.

Developments of polymer functionalized silk fibroin nanoparticles for oral drug delivery applications

Pham Duy Toan*, Nguyen Ngoc Yen, Nguyen Quoc Chau Thanh, Quach Thi Hong Dung, Ha Thi Kim Quy

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Silk fibroin is a biomaterial commonly utilized in numerous medical applications. However, limited information has been reported on fibroin usage in oral drug delivery. Thus, this study was conducted. Fibroin was successfully extracted from silk cocoons with a 20.08% extraction efficiency. The fibroin nanoparticles, functionalized with poly(vinyl alcohol) or Eudragit E100, were effectively formulated by the desolvation method, with nano-sizes and high stability in the simulated gastrointestinal condition. The Fourier-transform infrared (FT-IR) spectroscopy was used to examine the system structure, which revealed the distinctive peaks of all components. Using a scanning electron microscope (SEM), the nanoparticle system was spherical. In conclusion, the research successfully developed novel polymer-functionalized silk fibroin nanoparticles for oral drug delivery.

Salt tolerance threshold in Phan Rang sheep drinking with diluted seawater

Nguyen Thiet*, Dat Nguyen Thanh, Nguyen Trong Ngu

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The experiment aimed to evaluate the salt tolerance threshold in sheep drinking with diluted seawater was carried out on 10 rams, divided into two phases: Phase 1 (control, C) all rams were given fresh water for 7 days from two identical buckets, and daily water intake was recorded from both buckets. In phase 2 (preference test, PT), each ram was supplied with fresh water for the first bucket and diluted seawater (DSW) for the second bucket or vice versa. The concentration of DSW for preference tests ranged from 0.5% to 2.0%. The results from the experiment showed that body weight and dry matter intake did not differ by DSW, whereas water intake was significantly higher during phase 2 (P

The effect of formulation and pasteurization conditions on the quality of soursop juice (Annona muricata L.)

Huynh Thi Ngoc Mi, Doan Thi Kieu Tien*

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Soursop (Annona muricata L.) is one of the tropical fruits with high potential in producing juice, nectar, jam, frozen fruit pulp, and fruit pulp powder, bringing high economic efficiency. The study aims to investigate the influence of formulation conditions on the sensory quality of the product. The research was performed with the dilution ratio between puree and water (1:2, 1:2.5, 1:3, and 1:3.5), the addition of total soluble solids (TSS) content (16, 18, and 20 °Brix), pH value (3.3, 3.6, and 3.9), and the final product pasteurization conditions (75, 80, and 85°C for 5, 10, and 15 minutes, respectively). The results indicated the suitable conditions for processing soursop juice were 18 °Brix, pH 3.6, and a dilution ratio by weight of 1 part puree to 3 parts water, with final product pasteurization at 80°C for 10 minutes. The product met the Vietnamese Ministry of Health standards QCVN 6-2:2010/BYT, with a total acid content of 0.24% and vitamin C content of 1.47 mg%.

Composition of Plant Parasitic Nematodes on Giay Lime (Citrus aurantifolia) in some key cultivation areas in Tien Giang Province

Dang Thi Kim Uyen, Nguyen Gia Huy*, Tran Thi Thu Tram, Le Thi Ngoc Tien, Vo Thi Thanh Loc, Nguyen Van Hoa

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Giay lime (Citrus aurantifolia) is a commercially valuable crop widely cultivated in Tien Giang province. Meanwhile, plant parasitic nematodes are one of the factors that limit productivity and economic of giay lime and are of increased concern. This study identified the density and composition of nematodes on Giay lime trees in some main cultivated areas in Tien Giang province such as Cai Be, Cai Lay, Chau Thanh, Cho Gao districts and My Tho city. The results identified 8 types of nematodes, including Tylenchulus sp., Rotylenchulus sp., Aphelenchus sp., Pratylenchus sp., Helicotylenchus sp., Tylenchorhynchus sp., Xiphinema sp. and Paratylenchus sp.. The most significant frequency explored in the soil sample was Tylenchulus sp. (80%), followed by Rotylenchulus sp. (63.33%), Aphelenchus sp. (60%), Pratylenchus sp. (50%), Helicotylenchus sp. (46.67%), Tylenchorhynchus sp. (46.67%), Xiphinema sp. (36.67%) and the lowest was Paratylenchus sp. (3.33%). In roots, Tylenchulus sp. was (80%), Rotylenchulus sp. (63.33%), Pratylenchus sp. (46.67%), Tylenchorhynchus sp. (40%), Helicotylenchus sp. (33.33%). The nematode species Tylenchulus semipenetrans, Pratylenchus coffeae and Rotylenchulus reniformis were identified as species commonly present on the rhizosphere of Giay lime trees in Tien Giang province.

Study on CCR Gene Structure and Expression In Some Acacia (Acacia auriculiformis) Clones

Nguyen Tien Dung*, Duong Van Doan, Tran Thi Thu Ha

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Cinnamoyl-CoA reductase (CCR) is the main gene involved in lignin synthesis and is a DNA marker related to lignin content in plants. In this study, we evaluated the structure and expression of the CCR gene in 7 Acacia auriculiformis clones selected by the Vietnam Academy of Science and Forestry, named as Clt7, Clt18, Clt19, Clt25, Clt26, Clt43 and Clt57. Research results showed that the CCR gene isolated from the Clt has a highly similar sequence (98.8%) to the sequence of HQ317734 published on NCBI. The gene is 3,317bp long, including 5 exons and 4 introns, encoding 319 amino acids. Compared to HQ317734, the CDS region of the CCR_ Clt has some positions that have been deleted one or two nucleotides such as positions 108, 468, 630, 670, 671, 794, 796. Three AAA nucleotides at position 420-423 were substituted by TTT, and A was replaced by G at position 715. Analysis of gene expression by qT-PCR showed that the level of CCR expression was not significantly different from 7 Acacia clones.

Composition of plant parasitic nematodes on groundnuts in Tra Vinh province

Nguyen Gia Huy, Nguyen Thi Thu Nga*, Tran Vu Phen, N Van Hoa

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The composition of plant-parasitic nematodes (PPNs) associated with peanut crops was investigated in Duyen Hai, Cau Ngang, and Tra Cu districts of Tra Vinh province. The research methodology was based on morphological characteristics and morphometric indices, combined with biological indicators to evaluate soil community characteristics. The survey results identified 17 species, 10 genera of PPNs belonging to 8 families, including Pratylenchus coffeae, P. brachyurus, Ditylenchus ausafi, Helicotylenchus crenacauda, Hirschmanniella oryzae, H. mucronata, Mesocriconema curvatum, M. ornatum, Mesocriconema sp., Meloidogyne graminicola, Tylenchorhynchus leviterminalis, T. mashhoodi, T. nudus, T. annulatus, Tylenchus sp., Longidorus elongatus, and Xiphinema elongatum. Among them, Mesocriconema was prevalent in sandy soils, with a 100% occurrence rate. The study also recorded the presence of three genera (Pratylenchus, Tylenchorhynchus, and Hirschmanniella) in peanut roots, along with the presence of the Pratylenchus genus in peanut pods exhibiting black spot symptoms. Mesocriconema and Pratylenchus found in this study are significant parasitic agents on peanuts and require management measures.

Status of pig husbandry, infectious diseases and veterinary hygiene practices related to African swine fever in Ca Mau province

Lam Tran Bao Tran, Chung Huu Nghi, Tong Van Mo, To Quoc Huong, Doan Dinh Toan, Huynh Truong Giang, Truong Quoc Thai, Le Quang Trung, Tran Ngoc Bich, Nguyen Thanh Lam*

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This study aims to investigate the status of pig husbandry, infectious diseases, and veterinary hygiene practices related to African swine fever (ASF) in pigs in Ca Mau province. Secondary data regarding pig husbandry, and infectious diseases were collected via a retrospective survey of statistical data; primary data regarding veterinary hygiene practices was collected via a cross-sectional survey and direct interviews with 79 pig households. The results showed that the total pig herd of Ca Mau province decreased sharply in 2019 (22.98%) and 2020 (25.63%) compared to 2018 due to the impact of ASF. During the period 2019 – 2022, infectious diseases in pigs were caused by ASF. The results of the survey on the status of pig husbandry showed that the scale of pig farming was mainly household scale (89.87%); pigs were raised for meat (89.87%); long–term farming experience (>10 years) (50.63%); open system (63.29%); pig households used mixed feed (91.14%) and drilled wells (89.87%) in raising pigs. In addition, local households were concerned about the veterinary hygiene practices to prevent ASF infection.

Effect of pre-harvest fruit bagging on the quality of post-harvest violet star apple fruit (Chrysophyllum cainito L.) in Ke Sach district, Soc Trang province

Nguyen Thi Thuo*, Nguyen Thi Bich Hang, Vu Ba Quan, Tran Van Toan, Vu Quan, Le Trung Tam

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The experiment was conducted to evaluate the fruit bagging type and pre-harvest fruit bagging time to minimize the percentage of fruit flies while ensuring the yield and quality of violet star apple fruit. The experiment was conducted using a completely randomized blocks design, with two factors: (1) fruit bagging type (clear nylon, foam fabric, and a combination of clear nylon and foam fabric), non-bagged fruit as control; and (2 ) pre-haverst fruit bagging time (90 days, 120 days and 150 days after fruit set). The experiment was carried out on 7 year-old violet star apple fruit orchard in Trinh Phu and Xuan Hoa communes (Ke Sach district, Soc Trang province). The results showed that the use of fruit bagging type had reduced fruit flies by more than 96%. Clear nylon bag type was suitable for violet star apple fruit bagging ưith a low percentage of fruit flies (about 3,3%), high fruit weight (235 g), high Brix (14,1). The appropriate pre-harvest fruit bagging time was 90 days after fruit set.

Isolation and identification of Staphylococcus spp. in dogs with dermatitis in Ho Chi Minh city

Nguyen Thi Lan Anh, Nguyen Vu Thuy Hong Loan, Doan Thi Kim Cuc, Pham Thi Hai Hung, Nguyen Thuy Y Vi, Dao Huyen Tran, Nguyen Thanh Lam*

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This study aims to determine the prevalence of Staphylococcus spp. in dogs with dermatitis visiting veterinary clinics in Ho Chi Minh city using clinical examination, bacterial isolation and identification by PCR technique. A total of 96 swab samples were collected from skin of dogs with dermatitis. The results showed that the isolation rate of Staphylococcus spp. from dogs with dermatitis was 84.4%. The presence of Staphylococcus spp. free-ranging and semi-confined dogs (94.7%) was higher than confined dogs (69.2%). The prevalence of Staphylococcus spp. in dogs under one year old (62.5%) was lower than in those over five years (96.7%). A total of 105 Staphylococcus strains were isolated in this study, with the prevalence of coagulase-positive Staphylococcus (80.0%) being higher than that of coagulase-negative Staphylococcus (20.0%). In addition, four species of Staphylococcus spp. including S. aureus, S. pseudintermedius, S. epidermidis, and S. schleiferi were identified and S. pseudintermedius was isolated at the highest rate (49.5%).

Effect of inulin and Lactobacillus plantarum on growth performance and immune response of cultured striped catfish (Pangasianodon hypophthalmus) in pond

Bui Thi Bich Hang*, Tran Tuan Thanh, Nguyen Van Trieu, Nguyen Thanh Phuong

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The study was conducted to evaluate the effect of Lactobacillus plantarum (107 CFU/g feed) and 1% inulin dietary supplementation on the growth performance and immune response of striped catfish (Pangasianodon hypophthalmus). The experiment was randomly designed with 3 treatments including control (NT1), L. plantarum (107 CFU/g) 2 weeks interval (NT2), 1% inulin 2 weeks interval (NT3). Alltreatments weretriplicated. Sampling were done in the week 4th and 8th of L. plantarum (107 CFU/g) and 1% inulin supplementation. Immune parameters including total erythrocyte cells, total leucocyte cells, the number of each type of leucocyte and lysozyme activity were analyzed to evaluate fish immune response. The results showed that the growth performance, haematology and lysozyme activity in treatment NT2 and NT 3 were higher than those of the control treatment. In the treatment of 1% inulin 2 weeks interval - NT3, the growth performance and daily weight gain showed the highest values (42,42g and 0,61 g/day) in both sampling times and indicated the best immune response of fish.

Using Social constructivist theory in the teaching of solving problems of conditional probability grade 12

Bui Anh Kiet*, Tran Hieu Phat

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Social constructivist theory is formed from solving problems and receiving feedback from society. Socio-economic integration is also formed through interaction, debate, and exchange winthin the community. Socio-economic integration considers knowledge to be the product of a construction process, but this construction is social and not individual (subjective). “Conditional probability” is one of the topics closely related to social factors. It is also a new topic updated by the Ministry of Education in the Grade 12 Math curriculum, officially taught in 2024. Because the teaching tools and content are related to society. A teaching model for solving conditional probability exercises of the Grade 12 Math program was proposed based on social constructivist theory. After presenting the basic knowledge and formulas needed to solve conditional probability exercises, a 5-step problem-solving teaching model based on socio-economic theory were proposed.

Applying combined learning method to improve Kanji learning efficiency for students majoring in Japanese language at FPT Can Tho university

Nguyen Thi Phi*, Nguyen Ngoc Son Hai Van, Nguyen Thi Hong Van, Vuong Khanh Quynh

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Currently, many methods of learning Kanji have been proposed and applied such as learning through Flashcards, learning through Sino-Vietnamese sounds, learning Kanji characters from basic to complex, etc. However, the current situation showed that learners of Japanese are facing many difficulties, especially in learning Kanji. This study was conducted on 31 Japanese language students to find more effective and interesting learning methods. An experimental class was conducted by combining various learning methods such as learning Kanji with radicals, using sentences related to Sino-Vietnamese meaning and pronunciation, and writing over and over again. The results showed that more than 93% of students thought that this combined learning method was effective, helping to improve Kanji learning and remember Kanji longer. In particular, learners' Kanji writing ability improved significantly with 100% of students scoring 8 or higher. While this number only reaches 39% for traditional learning methods. This result showed that this learning method can be a supplementary method to help students learn more to improve their Kanji ability.

Simulation of conditional probability using R software

Bui Anh Kiet*, Trinh Phung Chi

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Conditional probability is a new content added to grade 12 in the 2018 Mathematics General Education Program. This is a completely new concept for high school students, requiring teachers to be highly qualified and thorough in teaching plans, teaching methods and teaching aids. The article presents the use of simulation in solving Conditional Probability problems, and proposed procedures for using R software in solving Conditional Probability problems.

Internal auditing in the public sector – A literature review and future research directions

Le Phuoc Huong*, Vu Xuan Nam, Tran Khanh Dung

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The main purpose of this study was to discuss the development, focus and criticisms of the literature on public sector IA and then propose directions for future studies. The study was to review 77 articles to discuss possible data sources, theories, types of organizational respondents, research instruments, and evaluating findings. Future research should examine the differences of IA in the public sector across countries, using theory for analysis, giving evidence regarding risk management and fruitless and wasteful expenditure, higher emphasis on the acquisition of IT skills, the effect of cultural, institutional and demographical characteristics in IA, and the design rigorous models to predict IA effectiveness.