The Capability of E-reviews in Online Shopping. Integration of the PLS- SEM and ANN Method

Purpose: The aim of this study is to investigate the impact of e-review on iGen's propensity to purchase online. Especially, it can be better understood by dissecting the relationship among 3 variables of e-review (review valence, quantity of e-review and quality of e-review), e-satisfaction, and intention to buy.   Theoretical framework: This study classifies e-reviews according to their valence, quantity, and quality based on the study of Khammash (2008).   Design/methodology/approach: The PLS-SEM method was used to analyze data collected from online surveys administered to a sample of 222 iGen in Ho Chi Minh City to assess the hypotheses behind the study. Additionally, the Artificial Neural Network technique was used to separate SEM predictors that were relatively important.   Findings:  There are three results from the investigation: It has been found that (1) e-satisfaction is positively affected by valence, (2) e-satisfaction is generally increased with the high quality of e-review, but the quantity of e-review does not necessarily affect customers' e-satisfaction, and (3) e-satisfaction given in the context of an e-commerce platform has a strong effect on customers' online shopping intention. This study sheds new light on iGen's online buying habits and offers valuable management implications for iGen, online merchants, and e-commerce sites.   Research, Practical & Social implications:  E-reviews have become a significant factor in determining consumers' online purchase decisions. They also assist iGen in understanding how a qualified e-review—one that is clear, understandable, helpful, and has enough justification to support the opinions—will be advantageous for other consumers who wish to shop online.   Originality/value:  Provides the theory of e-review and its role in the online business environment. In addition, understand more about the behavior of igen, an age with a huge amount of spending on an online shopping platform

A SURVEY ON COMMON ERRORS IN STUDYING SPEAKING SKILL OF ENGLISH-MAJORED FRESHMEN AT TAY DO UNIVERSITY, VIETNAM

Speaking is regarded as the most important aspect of communication skills, and it contributes to the success of language learners in their studies and careers, as well as the success of teachers in their teaching process. However, English-majored students, especially English-majored freshmen, usually face some errors in speaking English. Consequently, this research, entitled "A Survey on Common Errors in Studying Speaking Skills of English-majored Freshmen at Tay Do University" was conducted to figure out some common problems in speaking English that these English-majored students have encountered. The participants of this research were 80 students from two classes, English 15A and English 15B, at Tay Do University. The main research instrument for collecting the data was a questionnaire. The findings of this research pointed out the participants’ errors in speaking skills problems (pronunciation, grammar tense, pronunciation, mother tongue, vocabulary) and psychological problems (anxiety of error, lack of motivation, shyness, lack of confidence). The results showed that the students had errors in their speaking skills. Thanks to the results, some useful solutions were proposed for English-majored students.  Article visualizations

Factors Affecting Firms’ Performance: The Case of Vietnam construction firms

In the context of Vietnam's international economic integration, improving the performance of enterprises is increasingly important because it not only affects businesses but also affects the development prospects of the economy. The purpose of the paper is to consider the impact of factors on the performance of listed construction companies in the period of 2012-2018. By means of an empirical analysis, this study uses Eviews econometric software and table data techniques. This study found the factors that positively impact on performance are asset structure, capital structure and firm size that negatively impact the performance of Vietnam listed construction firms. These findings support business administrators in selecting appropriate business and production plans to increase the operating performance of businesses in the construction industry. Keywords: Profitability, construction firms DOI: 10.7176/RJFA/11-2-15 Publication date: January 31st 202

Research and Design of an X-Band UHF Power Amplifier

Introduction. A method for designing power amplifiers for use in the transmitting channels of X-band transceiver modules is investigated. The design process was aimed at optimizing the relationship between the basic amplifier characteristics, including the operating frequency band, output power level, output linearity, high harmonics suppression, etc.  Aim. Investigation of a method for designing an X-band UHF power amplifier, which is capable of optimizing the relationship between its main characteristics.  Materials and methods. Theoretical calculations were combined with experimental studies into the design of a UHF power amplifier. The stages of the design process are described in detail, including major ideas, principal circuits, and strip circuits. Evaluations were conducted using the Keysight ADS high frequency circuit simulation tool.  Results. A method for designing X-band UHF power amplifiers on the basis of a close combination of theory, simulation, and experimental adjustment was described in detail.  Conclusion. A prototype of an X-band PA was developed; an approach to developing a methodology for manufacturing, measuring, and testing X-band PAs is described.Introduction. A method for designing power amplifiers for use in the transmitting channels of X-band transceiver modules is investigated. The design process was aimed at optimizing the relationship between the basic amplifier characteristics, including the operating frequency band, output power level, output linearity, high harmonics suppression, etc.  Aim. Investigation of a method for designing an X-band UHF power amplifier, which is capable of optimizing the relationship between its main characteristics.  Materials and methods. Theoretical calculations were combined with experimental studies into the design of a UHF power amplifier. The stages of the design process are described in detail, including major ideas, principal circuits, and strip circuits. Evaluations were conducted using the Keysight ADS high frequency circuit simulation tool.  Results. A method for designing X-band UHF power amplifiers on the basis of a close combination of theory, simulation, and experimental adjustment was described in detail.  Conclusion. A prototype of an X-band PA was developed; an approach to developing a methodology for manufacturing, measuring, and testing X-band PAs is described

Hall Coefficient in the Presence of Strong Electromagnetic Waves Caused by Confined Electrons and Phonons in a Rectangular Quantum Wire

The analytic expression for the Hall Coefficient (HC) caused by the confined electrons in the presence of a strong electromagnetic wave (EMW) including the effect of phonon confinement in rectangular quantum wires (RQWs) is calculated by using the quantum kinetic equation for electrons in the case of electron - optical phonon scattering. It is because the expression of the HC for the confined phonon case contains indexes m, m' which are specific to the phonon confinement. The expression in a RQW is different from that for the case of unconfined phonons in a RQW or in 2D. The results are numerically calculated and discussed for a GaAs/GaAsAl RQW. The numerical results show that HC in a RQW can have both negative and positive values. This is different from the case of the absence of EMW and the case presence of EMW including the effect of phonon unconfinement in a RQW. These results are also compared with those in the case of unconfined phonons in a RQW and confined phonons in a quantum well. The conductivity in the case of confined phonon has more resonance peaks compared with that in case of unconfined phonons in a RQW. This new property is the same in quantum well. All results are compared with the case of unconfined phonons to see differences

Tannins: Extraction from Plants

The chapter presents mainly on different extraction methods of tannin. Some technical means required for effective extraction are also presented, for example, collection and treatment of plant and drying and storage of plant. Opportunity and challenges in application of extraction methods are also exhibited in the chapter

Study of antihyperglycaemic activity in streptozotocin induced diabetic mice and antioxidant activities of medicinal plant extracts

Some extracts of medicinal plants have demonstrated potential benefits in treatment of different diseases for centuries such as antihyperglycemic, antioxidant, anti-inflammatory, antibacterial. The purpose of this study is to evaluate the effect of extracts from several herbal plants, such as Gymnema sylvestre, Stevia rebaudiana, Cinnamomum cassia, Zea may, Ocimum basilicumon blood glucose level in streptozotocin (STZ) induced diabetic miceand to offer scientific proofs for the identified antihyperglycemic effect by investigating on mechanismsof the most effective extract. The results proved that diabetic mice treated with 70% ethanol extracts of Gymnema sylvestre leaves and Stevia rebaudiana leaves showed significant reduction of the blood glucose levels at a dose of 500 mg/kg body weight when compared to control (p0,05). Antihyperglycemic activity of Gymnema sylvestre (57,68%) and Stevia rebaudiana extracts (54,93%) were significantly higher than other extracts. The inhibition of α-amylase and α-glucosidase activity of Gymnema sylvestreand, Stevia rebaudiana extracts were carried out in vitro. The result demonstrated that these Gymnema sylvestre and Stevia rebaudiana extracts exerted significant inhibition and specific on intestinal α-amylase and α-glucosidases activities. Using 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay showed that Gymnema sylvestre and Stevia rebaudiana extracts exhibited relatively low antioxidant activity with the concentration of a sample required for 50% scavenging of the DPPH free radical of 115,88 ± 1,16 µg/ml and 160,27 ± 2,01 µg/mlcompared to vitamin C (49,16 ± 1,26 µg/ml).

EVALUATION OF THE VULNERABILITY OF THE COASTAL SOCIO-NATURAL SYSTEMS (EXAMPLE FROM KHANH HOA COASTAL ZONE)

Joint Research on Environmental Science and Technology for the Eart

Impacts of Foreign Direct Investment on Economic Development: Does Institutional Quality Matter?

The linkage between foreign direct investment (FDI) and economic development has been demonstrated in economic literature. In this study, we analyze the impact of FDI on economic development, considering the role of institutional quality in 63 provinces/cities in Vietnam in the period 2005–2022. Applying various regression methods, such as Pooled OLS, FEM, REM, GMM, and PVAR, the results confirm that foreign direct investment and institutional quality have a positive impact on economic development. Findings also provide evidence that institutional quality is an important factor in attracting FDI, determining both the quality and quantity of inflows from other countries into Vietnam. Some policy implications are given to promote the role of institutions and attract foreign direct investment, thereby promoting the economic development of provinces and cities in Vietnam. Doi: 10.28991/ESJ-2023-07-06-05 Full Text: PD