Journal of Science and Technology - IUH

A PROPOSING FOR MINING K SEQUENTIAL PATTERNS

2024-08-23T08:19:54+00:00

The problem of finding k sequential patterns from a sequence database has been researched and proposed to solve the problem of how users can choose a minimum support threshold to find the number k desired user patterns in the sequential pattern mining problem. This solution is highly appreciated because the implementation cost is much lower than the traditional sequential pattern mining problem. However, currently, the process of finding sequential patterns in the problem of finding k sequential patterns is built according to the pattern development and projection database approach, so it costs a lot of money to perform projections. To reduce execution time, this paper proposes to use prism block encoding method to represent pattern information and calculate pattern support. Experimental results show that the proposed method has better execution time than the projection method on projection database.

HARMONIC REDUCTION FOR SINGLE-PHASE UNINTERRUPTIBLE POWER SUPPLY INVERTER

2025-03-05T02:09:54+00:00

Numerous control strategies for Uninterruptible Power Supply (UPS) inverters have been proposed, with the primary objectives of voltage tracking, stability, and maintaining a perfect sinusoidal waveform even under nonlinear loads, varying loads, and the presence of disturbances.

A proposed method is two Multiple Loop Control (MLC) with an outer voltage control loop tracking the reference voltage and an inner current control loop to reduce the steady-state error of the load voltage, reduce harmonics in the main circuit current, and improve system efficiency. The controller's robustness based on the Lyapunov function is proven by sudden load changes and variations in the reference voltage along with the presence of noise. The fundamental principles of Lyapunov's theorem are applied to the state equations to calculate the switching function for generating Pulse Width Modulation (PWM) to reduce harmonics in UPS.

Simulations and experiments were conducted using MATLAB-Simulink. Results demonstrated that the UPS output voltage and current can track the reference values from low to high, regardless of sudden load changes or reference voltage variations, and in the presence of noise. The total harmonic distortion (THD) of the current was significantly reduced to 0.04%, meeting the IEEE-519 standard.

DESIGNING A TEACHING MODEL COMBINED WITH THE SUPPORT OF ARTIFICIAL INTELLIGENCE (AI) TECHNOLOGY. A TYPICAL STUDY IN TRAINING STUDENTS IN ELECTRICAL - ELECTRONICS ENGINEERING

2024-10-17T01:28:15+00:00

Abstract: Blended-learning (DHKH) is a form of teaching that has been researched and widely deployed at universities around the world. Along with that, research shows that artificial intelligence technology (Artificial Intelligence - AI) is currently becoming an important tool in many fields, including education. The combination of higher education and AI brings many significant benefits and positive impacts in the teaching process. The article points out that AI contributes to promoting the effectiveness of scientific teaching, learning activities supported by AI that take place smoothly in online and in-person environments will help lecturers (teachers) maximize their effectiveness. teaching methods, training practical skills for students, improving self-study capacity, thereby improving the quality of human resources of engineering sectors in general and the Electrical Engineering Technology sector - Electronics in particular aims to meet the requirements of employers during the integration period.

CHALLENGES IN GROUP WORK ACTIVITIES OF STUDENTS IN NON-MAJOR ENGLISH CLASSES

2025-02-26T06:35:56+00:00

The study was conducted to examine the attitudes and difficulties of students through group work activities in English classes. The findings indicated that the students held divergent perspectives regarding the group. However, the majority of them expressed an interest in working in a group and deemed it an efficient means of enhancing their language proficiency. Particularly, the students exhibited fondness for this type of task. I found it enjoyable. A limited number of students expressed a lack of interest and displayed a neutral concern regarding group work, with only a small percentage expressing a negative attitude. The findings demonstrated that students experienced various problems when they were involved in group work, such as overuse of native language, arguments, losing face, or being controlled. From the study, it is suggested that there are some significant modifications that would improve the success of group work activities.

LEARNER AUTONOMY IN LMS READING ASSIGNMENTS: A STUDY ON STUDENT PARTICIPATION AND THEIR PERSPECTIVES AT A UNIVERSITY IN HO CHI MINH CITY

2024-09-18T08:59:48+00:00

This study examines the role of the learning management system in promoting learner autonomy and reading comprehension among English students at a Vietnamese university. With the rise of technology in higher education, it is paramount to understand the effectiveness of Learning Management System (LMS) in promoting independent learning. Using a mixed methods research design, the study assesses students' engagement in LMS reading tasks, collects students' and instructors' perspectives, and evaluates the overall contribution of LMSs to learner autonomy. Quantitative data from outcome analysis of 160 students and qualitative insights from questionnaires show that while LMS platforms ensure accessible and structured learning experiences, their success in promoting autonomy depends on differentiated pedagogical integration and digital literacy. The results highlight the importance of strategic LMS implementation and highlight the need to focus on learner-centered approaches to maximize educational outcomes. The study offers practical recommendations for optimizing the use of LMS in language teaching and highlights the interaction of technology and pedagogy in facilitating autonomous learning. Although the study is limited due to its sample size and reliance on digital tools, it suggests avenues for future research, including cross-institutional studies and exploration of new LMS technologies.

COMMERCIAL ACTIVITIES IN AN GIANG PROVINCE UNDER THE NGUYEN DYNASTY (1802 – 1867)

2025-01-21T03:27:57+00:00

The commercial activities of An Giang province from 1802 to 1867 developed based on important foundations in geography, economy, and politics. Strategically located within the Mekong River basin and bordering Cambodia, An Giang was endowed with a rich river network and abundant natural resources, especially fertile alluvial soil and diverse aquatic resources. Concurrently, the Nguyen dynasty’s policies on reclamation and frontier development facilitated the formation and expansion of commercial activities. During this period, trade in An Giang focused on the exchange of rice, aquatic products, and forest products—the primary commodities of the region. Traditional markets and floating markets along the Hau River and Vinh Te Canal served as central trading hubs, catering not only to local demands but also connecting trade with Cambodia and other southern provinces. Notably, the involvement of Chinese merchants fostered the exchange of goods between An Giang and international markets. This article analyzes three main aspects: (1) the foundations of An Giang's commerce, including natural conditions and the border management policies of the dynasty; (2) the primary commercial activities, encompassing the exchange of rice, aquatic products, floating and traditional markets, and the role of Chinese merchants in linking domestic and international trade; (3) the role of commercial activities in promoting local economic development and contributing to the prosperity of southern Vietnam, thereby confirming An Giang's strategic position in the regional trade system.

PROPOSING AN IQA MODEL FOR GENERAL ENGLISH CURRICULUM AT INDUSTRIAL UNIVERSITY OF HO CHI MINH CITY

2024-09-06T02:23:16+00:00

The construction of internal quality assurance (IQA) for academic programs is crucial for higher education institutions (HEIs) to achieve internationalization, meet employer requirements, and fulfill social accountability. In Vietnam, the quality of General English programs at HEIs is a significant concern, as many Vietnamese students fail to meet minimum exit level requirements, hindering both educational internationalization and employer satisfaction. Ensuring the quality of General English teaching and learning is therefore critical. This study aims to develop an IQA model for General English programs, incorporating three key factors: policy and human resources, instruments, and specific criteria. The first two factors are adapted from an existing QA model, while the criteria are based on the National ELT Accreditation Scheme (NEAS) to ensure the quality of General English teaching for non-English majors. The research uses a quantitative approach, employing survey questionnaires for data collection and analysis, to assess the applicability of NEAS accreditation standards for QA in General English teaching at Industrial University of Ho Chi Minh City (IUH). A qualitative method validates the feasibility of the proposed IQA model. The findings indicate that both experts and English lecturers at IUH recognize the applicability, feasibility, and effectiveness of the NEAS standards and the proposed criteria.

THE CURRENT STATE OF PESTICIDE USE BY FARMERS IN RICE CULTIVATION IN TRANG BANG TOWN - TAY NINH PROVINCE

2024-12-13T08:14:28+00:00

This study was conducted to investigate and evaluate the current status of pesticide use in rice cultivation in Trang Bang Town, Tay Ninh Province. Primary data was collected through a sociological survey and interviews with representatives of farming households in the study area, while secondary data was obtained from the town's environmental resources department. The results showed that pesticides were frequently used in cultivation, 27 types of pesticides were commonly applied in Trang Bang Town. Farmers placed greater emphasis on pesticide efficiency (91.30%) and cost (88.69%) than on related environmental issues (44.35% - 52.17%) and health impacts (67.83%). Pesticide usage was often based on farming experience (30.43%), and farmers did not strictly adhere to technical regulations and guidelines regarding dosage and application methods. While farmers were aware of the need to collect pesticide packaging, they did not consistently sort and store it separately, with many households mixing it with household waste. There is a need to intensify outreach and training activities to enhance farmers' understanding of the properties, usage, and environmental and health impacts of pesticides, enabling them to make informed decisions when using these chemicals.

EFFECTS OF BIOCHAR PYROLYSIS TEMPERATURES ON THE PHOSPHORUS ABSORPTION CAPACITY OF ACRISOL SOIL (TAY NINH): BIOCHAR FROM QUAIL DUNG

2025-03-13T03:16:43+00:00

Phosphorus (P) is a critical macronutrient for plant growth. Previous research suggests that biochar derived from livestock waste can be an effective strategy for maintaining soil P availability. This study investigated the impact of biochar amendment on available P adsorption capacity in Happlic Acrisols of Tay Ninh Province, Vietnam. Quail dung biochars were prepared using a temperature range of 300-600 °C, with three specific pyrolysis temperatures of 300, 450, and 600 °C. A batch adsorption experiment was conducted to evaluate the effect of using biochar amendment (4% w/w) on soil P adsorption compared to a control treatment (unamended soil). Soil samples were equilibrated with varying phosphate solution concentrations at different time points to assess P adsorption capacity after adding. The effects of biochar pyrolysis temperature on soil properties and phosphate (P) adsorption were investigated. Key findings include: increased soil pH and pHpzc with increasing pyrolysis temperature of the biochar amendment. The recovery efficiency of biochar, total organic carbon (TOC), and cation exchange capacity (CEC) of the soil decreased with higher pyrolysis temperature. Adsorption data followed both Langmuir and Freundlich isotherm models, indicating different binding mechanisms for phosphate on the biochar surface. The maximum P adsorption capacity varied depending on the pyrolysis temperature. The pseudo-second-order kinetic model were fit for the P adsorption process, suggesting a chemisorption mechanism involving chemical interactions between biochar and phosphate ions. This finding aligns with the potential for biochar derived from quail dung pyrolyzed at 300 °C to serve as a viable strategy for enhancing P adsorption capacity in Happlic Acrisols of Tay Ninh Province, Vietnam.

APPLICATION OF CELLULOSE/TiO2 MATERIALS SYNTHESIZED FROM BANANA WASTE FOR ANALYZING MALACHITE GREEN IN WATER AND SHRIMP SAMPLES

2024-11-01T01:54:33+00:00

The Cellulose/TiO₂ material was synthesized from banana peels, and its properties were characterized using SEM, FTIR, XRD methods. The material was applied for adsorption to enrich Malachite Green under solid-phase extraction conditions such as pH, material mass, adsorption time, and desorption solvent, respectively investigated to achieve the highest adsorption and desorption efficiency. The results showed that using 100 mg of adsorbent material for 60 minutes at pH 7 resulted in an adsorption efficiency of 94.64% with a maximum adsorption capacity of about 79.42 mg/g of material. Ethanol/HCl 1M (8:2) was the desorption solvent for Malachite Green with a desorption efficiency of 100% at an initial concentration of 100 mg/L. Under optimal conditions, Malachite Green was determined by UV-VIS spectrophotometry in the linear range of 0.1 ÷ 20.0 mg/L (r² = 0.9977) with detection and quantification limits of 0.023 mg/L and 0.068 mg/L, respectively; the recovery efficiency of the method was about (96.28 ± 1.58) %. The method was applied to determine Malachite Green in shrimp aquaculture water and shrimp samples.

ANTIOXIDANT AND IMMUNOMODULATORY EFFECTS OF ETHANOL EXTRACT FROM Oldenlandia capitellata Kuntze LEAVES IN INDOMETHACIN-INDUCED GASTRIC INFLAMMATION IN MICE

2024-10-16T02:42:34+00:00

This study evaluates the antioxidant and immunomodulatory effects of the ethanol extract from Oldenlandia capitellata (EEOC) in a mouse model of indomethacin (IND)-induced gastric inflammation. Mice were subjected to treatment with IND (45 mg/kg), the standard drug omeprazole (OME) (20 mg/kg), and EEOC at varying doses of 100 mg/kg, 200 mg/kg, and 300 mg/kg. Key parameters assessed included malondialdehyde (MDA), hydrogen peroxide (H₂O₂), glutathione (GSH), total antioxidant capacity (TAC), catalase (CAT), superoxide dismutase (SOD), white blood cell (WBC) counts, Nitroblue tetrazolium reduction test (NBT), T-independent (TI), and phagocytic activity (PA). Results indicated that the IND group exhibited significantly elevated MDA (3.57 ± 0.03 nmol/mg protein) and H₂O₂ (2.15 ± 0.04 nmol/g tissue) levels (p < 0.05), reflecting oxidative stress and tissue damage. Treatment with EEOC led to notable reductions in both MDA and H₂O₂, particularly in the EEOC 300 group, which showed MDA levels of 2.26 ± 0.01 nmol/mg protein and H₂O₂ levels of 1.36 ± 0.02 nmol/g tissue (p < 0.05). Additionally, the EEOC administration restored GSH and TAC levels, along with enhancing CAT, GPx, and SOD activities. Furthermore, the EEOC treatment resulted in decreased WBC, NBT, TI, and PA counts and improved phagocytic activity, demonstrating its capacity to modulate immune responses. These findings suggest that EEOC effectively alleviates oxidative stress and enhances immune function in the context of gastric inflammation, highlighting its potential as a therapeutic agent for managing oxidative stress-related conditions.

ENERGY AND BONDING STATE CALCULATIONS OF ADSORBED CH3OH ON 2Pd/ZnO ADSORBENT SURFACE USING DENSITY FUNCTIONAL THEORY STUDY

2024-08-23T03:02:31+00:00

In this examination, the density functional theory (DFT) was used to investigate the calculated energies and structures of two Palladium atoms (2Pd) adsorption on ZnOsurface, forming 2Pd deposition over the ZnO surface model, namely 2Pd/ZnO adsorbent surface. Then, 2Pd/ZnO was employed to adsorb CH₃OH (methanol) molecule in gas phase. In the detailed performances, 2Pd was adsorbed at many positions on ZnO surface to obtain four structural sites and energies of 2Pd/ZnO adsorbent surface, called as site A, site B, site C, and site D. Herein, based on the resulted calculations of adsorption energies pointed out that the structural 2Pd/ZnO adsorbent surface of site A was the most stable one. Hereafter, 2Pd/ZnO adsorbent surface of site A was used to adsorb CH₃OH molecule in gas phase. There were six- adsorbed CH₃OH at positions on site A with structure and energy was found namely as from ADS-A to ADS-F, in which ADS-A and ADS-B to be the initially- stable sites in considering details.

APPLYING THE THEORY OF CONSUMER VALUE AND TRIPLE BOTTOM LINE: A STUDY OF CUSTOMER SATISFACTION AND LOYALTY IN MOBILE PAYMENT APPLICATIONS

2024-10-23T09:52:46+00:00

This study was conducted to measure the impact of consumer values and corporate social responsibility on customer loyalty when using mobile payment applications under the mediation of satisfaction. The research model was developed based on the Theory of Consumer Value (TCV) and the Triple Bottom Line (TBL). The data was collected through a convenient survey of 360 customers who used mobile payment applications in Ho Chi Minh City. The Structural Equation Model (SEM) was used to examine the research hypotheses. The results show that consumer values and social responsibility have a positive impact on loyalty and confirm the mediating role of satisfaction. Then, some managerial implications were proposed to help businesses improve customer loyalty, production, and business efficiency.

THE IMPACT OF TRUST AND SYSTEM DESIGN ON E-MARKETPLACE ADOPTION BY SUPPLIERS IN VIETNAM

2025-04-29T11:13:05+00:00

This study analyzed factors influencing e-commerce adoption by suppliers in Vietnam, focusing specifically on the mediating role of trust and the impact of e-marketplace system design. The research objective was to develop an integrated model to assess e-commerce adoption, analyze the mediating role of trust, and examine the impact of e-marketplace system design. The study employed a quantitative approach with data collected from 515 suppliers in Vietnam and analyzed using PLS-SEM structural equation modeling. Results showed that perceived usefulness, trust, and seller data security positively influenced e-commerce adoption, while perceived ease of use had no direct effect. Seller data security had the strongest overall influence, primarily through indirect effects. The study concluded that e-marketplaces should focus on enhancing data security, emphasizing business benefits, and building trust to attract more supplier participation.

THE CAUSAL RELATIONSHIP BETWEEN INCOME IVERSIFICATION AND PROFIT OF VIETNAMESE COMMERCIAL BANKS

2024-12-12T07:52:52+00:00

Studying the causal relationship between income diversification and bank profits with data including 32 Vietnamese commercial banks, period 2007-2022. The author uses the PVAR estimation method and Granger test to estimate this causal relationship. The research results show a causal relationship between income diversification and bank profits. In addition, specific factors such as scale, equity, deposits, and macroeconomic factors also affect this causal relationship. The higher the diversification, the higher the profit, and vice versa, the higher the profit is the reason to strongly promote bank diversification activities. However, when considering risks, the higher the diversification, the lower the banks' profit. This empirical evidence is the basis for suggesting some policies for bank managers, investors, and policy makers.

FACTORS AFFECTING PURCHASE INTENTIONS OF YOUTH IN HO CHI MINH CITY FROM LIVESTREAM SALES ON THE TIKTOK PLATFORM

2024-10-23T08:09:22+00:00

Currently, TikTok has become one of the most popular social networking applications, attracting the attention of consumers, especially young people. Instead of shopping in person, customers now prefer to shop through live streaming on TikTok, which is becoming increasingly popular. This is considered the most authentic form of purchase because customers are not fooled by edited images or fake reviews in articles. Therefore, this study aims to identify factors that influence young people's purchase intentions from live streaming on the TikTok platform in Ho Chi Minh City. Specifically, the research will focus on analyzing six factors: price promotions, limited-time promotions, consumer interaction with live streamers, consumer-to-consumer interaction, streamer appeal, trust. The study combined both qualitative and quantitative methods. The author sent the survey via Google Form and received 230 valid responses. The collected data will be analyzed and evaluated using SPSS 20 software, the results show that all six factors have a positive impact on purchase intention. Based on these findings, the author proposes some management implications to help businesses optimize their sales strategy on TikTok, improve business efficiency and increase purchase intention

DESIGN AND TESTING OF THE MOLD SYSTEM STRUCTURE OF UNBURNT BRICK PRESS MACHINE

2024-10-24T01:32:52+00:00

Hiện nay gạch không nung được sản xuất và ứng dụng trong thực tế xây dựng các công trình tại Việt Nam, nhưng chưa có công trình nghiên cứu nào phân tích độ tin cậy thiết kế kết cấu hệ thống khuôn của máy ép gạch không nung. Bài báo này nghiên cứu phân tích độ tin cậy thiết kế hệ thống khuôn, hệ thống rung, bàn rung, thanh đỡ palet và kiểm nghiệm các thông số kỹ thuật sản phẩm gạch. Kết quả phân tích cho thấy khuôn đực giá trị ứng suất cực đại ( Pa), ứng suất nhỏ nhất ( Pa), giá trị lớn nhất của chuyển vị chỉ là (mm), sức căng bề mặt lớn nhất là (mm). Hệ thống rung số vòng quay 3000 vòng/phút, lực kích rung 3210N, công suất 0,27kw, khối lượng 9,8kg, tần số 50Hz. Bàn rung giá trị ứng suất cực đại (Pa), ứng suất nhỏ nhất (Pa), giá trị lớn nhất của chuyển vị là (mm), sức căng bề mặt lớn nhất là (Pa). Thanh đỡ palet giá trị ứng suất cực đại (Pa), ứng suất nhỏ nhất (Pa), giá trị lớn nhất của chuyển vị chỉ là (mm), sức căng bề mặt lớn nhất là (Pa). Khối lượng viên gạch 1.4kg, cường độ chịu nén 78km/cm², độ thấm nước 1.6ml/cm²/h, độ ngậm nước bão hòa 9%, hệ số dẫn nhiệt 0.65w/m^ok, hệ số cách âm 39dB, độ rỗng tương đương 45%, chất lượng bề mặt đạt yêu cầu. Kết cấu đảm bảo độ cứng vững và an toàn trong quá trình làm việc. Sản phẩm gạch đạt tiêu chuẩn về chất lượng gạch không nung sử dụng tại Việt Nam.

INVESTIGATION OF THE INFLUENCE OF SUPERSTRUCTURE FLEXIBILITY ON THE BEHAVIOR OF BASE-ISOLATED STRUCTURES

2024-12-24T07:50:28+00:00

The use of single friction pendulum bearings in seismic design with base isolation techniques has become popular worldwide, and its damping efficiency is highly regarded. However, the disadvantage of base isolation techniques is the large lateral displacement of the bearings and the superstructure. Therefore, the maximum lateral displacement of the bearings is always a major concern during the design process. In preliminary design, this parameter is allowed to be quickly determined using the equivalent lateral force procedure. According to this method, the superstructure is assumed to be a rigid body when certain specified criteria are satisfied. This assumption can be the cause of distortion in the behavior of the isolated structure. This study aims to investigate the influence of structural flexibility on the maximum displacement of the bearings and the absolute acceleration of the superstructure. The time history analysis results from various numerical models using OpenSees software were utilized for evaluation.

APPLYING FUZZY ALGORITHMS TO PREDICT JOB POTENTIALS BASED ON CAPABILITY AND AGE FACTORS OF WORKERS IN CONSTRUCTION

2025-03-12T07:44:20+00:00

This article focuses on applying fuzzy algorithms to predict employment potential in the construction industry based on the factors of skills and age of workers. The construction sector plays a crucial role in the economic development of a country. We gather information on the skills and age of workers in this field and construct a prediction model using fuzzy algorithms. This model provides valuable insights for recruitment and workforce allocation in the construction industry. By leveraging the flexibility and ability to handle uncertain data of fuzzy algorithms, we believe that this article will contribute to optimizing the recruitment process and developing human resources in the construction sector.