Update propagation algorithms for supporting disconnected write in mobile wireless systems with data broadcasting capability

We develop and analyze algorithms for propagating updates by mobile hosts in wireless client-server environments that support disconnected write operations, with the goal of minimizing the tuning time for update propagation to the server. These algorithms allow a mobile host to update cached data objects while disconnected and propagate the updates to the server upon reconnection for conflict resolutions. We investigate two algorithms applicable to mobile systems in which invalidation reports/data can be broadcast to mobile hosts periodically. We show that there exists an optimal broadcasting period under which the tuning time is minimized for update propagations. We perform a comparative analysis between these two update propagation algorithms that rely on broadcasting data and an algorithm that does not, and identify conditions under which an algorithm should be applied to reduce the total tuning time for update propagation by the mobile user to save the valuable battery power and avoid high communication cost. For real-time applications, we address the tradeoff between tuning time and access time with the goal to select the best update propagation algorithm that can minimize the tuning time while satisfying the imposed real-time deadline constraint. The analysis result is applicable to file/data objects that mobile users may need to modify while on the move

EMPLOYEE COMMITMENT TO ORGANIZATIONAL CHANGE WITH THE ROLE OF JOB SATISFACTION AND TRANSFORMATIONAL LEADERSHIP

This study aimed to analyze the role of job satisfaction and transformation leadership for employees’ commitment to organizational change. Based on a survey sample of 381 employees in post-merger enterprises in retail and pharmaceutical sector and a linear regression model. The results revealed that Transformational leadership was associated positively and significantly with Affective Commitment (β = .42, p \u3c .000), Normative Commitment (β = .32, p \u3c .000), and Continuance Commitment (β = .27, p \u3c .000); Job satisfaction was associated positively and significantly with Affective Commitment (β = .24, p \u3c .000) and Normative Commitment (β = .30, p \u3c .000) among employees’ to organizational change. The results of this study provide a foundation of theory and practice for organizational changes that can efficiently exploit the human resource for the development in the next period

SEASONAL VARIATION OF PHYTOPLANKTON FUNCTIONAL GROUPS IN TUYEN LAM RESERVOIR, CENTRAL HIGHLANDS, VIETNAM

Seasonal changes in freshwater phytoplankton assemblages at Tuyen Lam Reservoir in the Central Highlands of Vietnam were classified into 23 functional groups based on physiological, morphological, and ecological characteristics. A total of 168 species were recorded during 10 surveys from 2015 to 2019 at 7 sampling sites, with Chlorophyta dominating in number of species. Phytoplankton abundance varied from 0.18×105 to 21.2×105 cells/L during the study period, mainly due to cyanobacteria. Seven of the 23 functional groups were considered to be dominant (relative density > 5%).  The dominant functional groups were groups M and G in the dry season and groups M, G, P, and E in the rainy season. Group M (Microcystis aeruginosa) was the most common in both seasons, while group P (Closterium, Staurastrum, Aulacoseira), group E (Dinobryon, Synura), and group G (Sphaerocystis, Eudorina) were more common in the rainy season. The Shannon diversity index (H¢) showed that phytoplankton communities were relatively diverse and that most of the study sites were lightly polluted. However, the ecological status has deteriorated at some locations due to the overgrowth of group M, leading to eutrophication in this reservoir. This study highlights the usefulness of functional groups in the study of seasonal changes in phytoplankton dynamics. Functional groups are applied for the first time at Tuyen Lam Reservoir and can be used to predict early-stage cyanobacterial blooms in future studies

WATER QUALITY STATUS OF WHITE LEG SHRIMP FARMING AREAS IN BINH DAI DISTRICT, BEN TRE PROVINCE, VIETNAM

This study focused on water quality assessment of farmed shrimp ponds in Binh Dai District, Ben Tre Province. The goals of the study were to provide chemical parameters of pond water for farmers, to identify problems and causes in farmed shrimp related to water quality and disease, and to help managers find appropriate solutions to minimize damage to local shrimp farming. Water samples were collected monthly from January to June 2021 from 90 vannamei farmers in six different areas, including Vang Quoi Dong, Dinh Trung Binh Thoi, Phu Long, Phu Vang, and Binh Thang of Binh Dai District. Parameters investigated in this study included pH, alkalinity, NH4+, NH3, NO2- and three other minerals. Water quality parameters were analyzed based on APHA standard analysis methods. The results showed that the water quality of shrimp farming areas in Binh Dai fluctuated from time to time, and water quality parameters were suitable for vannamei shrimp farming. However, the concentration of NO2- was always higher than the permitted threshold. The results from cluster analysis and MANOVA testing showed that water quality of the shrimp farming areas in Binh Dai was significantly different (p < 0.05), especially NO2-, Ca, Mg and alkalinity. These findings suggest that farmers must apply proper solutions for water quality management in each farming area to maximize crop production

A SOCIAL SURVEY ON COMMUNITY RESPONSE TO ROAD TRAFFIC NOISE IN HANOI

Joint Research on Environmental Science and Technology for the Eart

STUDY ON LEARNING AUTONOMY STRATEGIES FOR ENGLISH SPEAKING SKILLS OF HIGH-QUALITY FIRST-YEAR STUDENTS, SCHOOL OF FOREIGN LANGUAGES, CAN THO UNIVERSITY, VIETNAM

This study examined the challenges of self-studying English-speaking skills for first-year English studies majors at Can Tho University. The study aimed to answer questions such as: What self-study strategies can first-year students majoring in high-quality English at School of Foreign Languages at Can Tho University apply to develop speaking skills? The target audience was 96 English studies majors who have studied speaking and listening at Can Tho University. A questionnaire and an interview with 13 students were used to collect data for this study. In order to support the quantitative data, a questionnaire was used, while an interview was used for the qualitative data. This study aimed to find out the difficulties encountered by students, thereby proposing solutions to overcome them and improve the quality of their learning autonomy or self-studying English-speaking skills.  Article visualizations

Factors affecting consumer’s bargaining behavior: The case of fashionable clothing

Shopping is one of the current trends of the Vietnamese. According to Nielsen’s research results about consumer confidence in the fourth quarter of 2017, more than half of Vietnamese people (51%) use their spare money to buy new clothes at modern business models such as supermarkets, shopping centers, or at very traditional models like street vendors and wet markets where haggling (also known as bargaining) is considered as a common habit for Vietnamese. This is due to business characteristics from a very long time ago in Viet Nam. The bargaining behavior is not so hard to recognize in shopping. Even now, a large part of foreign tourists is familiar with the bargaining culture. This study aimed to discover bargaining behavior, the factors affecting such a behavior in buying fashionable clothing of the consumers in Ho Chi Minh City, and to consider whether the differences in bargaining behavior exist among different groups of gender, age, and income. The research was conducted using mixed methods concluding qualitative research (in-depth interview and focus group) and quantitative one (survey). The results showed that Attitude towards bargaining, Perceived behavioral control, Interest in bargaining affect Consumer’s bargaining behavior when buying fashionable clothes. Results were validated in Ho Chi Minh City context, and some conclusions were also presented

SYNTHESIS AND COMPARATIVE PHOTOLUMINESCENCE OF CdZnSe / ZnS AND CdZnSe / ZnSeS ALLOY QUANTUM DOTS

In order to search for new structures and compositions of quantum dots, suppress the blinking photoluminescence (random changes between high emission state ( on) and low emission status ( off ) under continuous photo- excitation ) and serve the application purposes in bio- medical and in optoelectronic devices , we have studied the fabrication of new alloy quantum dots ( QDs ). In this paper, we present new results on alloy core / shell quantum dots, with changed alloy shell composition, that was CdZnSe/ZnSexS1-x a ML with x ( x = 0 , 0.2, 0.4, 0.5 , 0.6, 0.8) and the shell thickness in monolayer (ML) ( a = 2 , 4 , 6 ) . The emission spectra and the intensity change according to the composition of the alloy shell. The full width a half maximum ( FWHM ) of the emission spectra of quantum dots CdZnSe is 25.5 nm. Covered with a shell layer, the emission intensity of the CdZnSe core increases along with the shell thickness. For comparison purpose, two different shell materials have been used, which are ZnS and ZnSeS alloy. With the same shell thickness, the emission wavelengths and intensity of the QDs change when the shell’s composition changes.The photoluminescence (PL) decay and the PL blinking of the alloy QDs was studied. It was shown that the alloy QDs spent by the nanocrystal in the ON state ranged typically between 20 and 40 %, and was dependent on the core composition. Detailed discussions on the experiment results are presented

Acute Kidney Injury After Percutaneous Coronary Intervention Guided by Intravascular Ultrasound

Purpose We investigated the impact of intravascular ultrasound guidance on reducing the incidence of contrast-induced acute kidney injury (CI-AKI) in patients undergoing percutaneous coronary intervention (PCI). Methods Ninety-nine patients were enrolled in this prospective cohort who were not randomly assigned to angiography-guided percutaneous coronary intervention or intravascular ultrasound-guided percutaneous coronary intervention. The patients were hospitalized at the Vietnam National Heart Institute - Bach Mai Hospital between 2019 and 2020. Acute kidney injury incidence during hospitalization was the primary endpoint. Results A total of 99 patients were divided into two groups: the intravascular ultrasound-guided group (33 participants) and the angiography-guided group (66 participants). The mean ± SD contrast volume of each group was 95.2 ± 37.1 mL and 133.0 ± 36.0 mL for the ultrasound-guided and angiography-guided groups, with P \u3c 0.0001. Intravascular imaging-guided percutaneous coronary intervention (IVUS-guided PCI) was associated with reduced acute kidney injury incidence during hospitalization: 0.0% vs. 12.12% and P = 0.049. Conclusions Intravascular ultrasound is a safe imaging tool that guides percutaneous coronary intervention and significantly reduces the rate of acute kidney injury compared to angiography alone. Patients who have a high chance of experiencing acute kidney injury benefit from using intravascular ultrasound

HAEMAGGLUTINATION ACTIVITY OF THE EXTRACTS FROM SOME VIETNAM MARINE INVERTEBRATES

Aqueous extracts from 21 species of Vietnam marine invertebrates, including 11 bivalve and 10 gastropod species, were examined for haemagglutination activity using native and enzyme-treated different animal and human erythrocytes. The 8 bivalve and 10 gastropod species were found to have haemagglutinination activities toward at least one type of erythrocyte tested. A total of 86% of marine invertebrate species surveyed were active. Strong activity was detected in extracts from two bivalve species (Tridacna squamosa and Geloina coaxans) and three gastropod species (Tutufa rubeta, Pleuroploca trapezium and Tectus conus) with enzyme-treated rabbit, horse and human A, B, O erythrocytes. In a haemagglutination–inhibition test with various monosaccharides and glycoproteins, haemagglutination activities of two extracts from T. rubeta and P. trapezium had no affinity for any of the monosaccharides and glycoproteins tested, while activities of the extracts from T. squamosa and T. conus were strongly inhibited by porcine stomach mucin tested, suggesting the presence of lectins specific for O-glycans of these species. The activities of four marine invertebrate extracts were stable over a wide range ofpH and temperature. The haemagglutination activities of T. rubeta and P. trapezium extracts were independent of the presence of divalent cations, whereas the haemagglutination activity of extracts from T. squamosa and T. conus were slightly dependent on the presence of divalent cations. The results suggest that Vietnam marine invertebrates may be good sources of useful lectins for biochemical and biomedical applications