170 research outputs found
Impacts of pollution discharges from Dinh Vu industrial zone on water quality in the Hai Phong coastal area
The hydrodynamic and water quality models (the Delft3D model) were established based on the measured data and the estimated pollution discharges from Dinh Vu industrial zones to Nam Trieu estuary. With seven separate simulation scenarios, the results show that in case of increased wastewater with the control of pollution discharge (water and concentration), the impact of pollution is only limited to a small area around the discharge point. Their influences on water quality in other areas in Nam Trieu estuary are quite small. Meanwhile, in case of environmental risk, a strongly increasing pollution load would cause the significantly increasing pollutant concentration in this area, they have almost exceeded the value in the National Technical Regulation on surface water quality (QCVN 10-MT:2015/BTNMT), such as NH4, COD, and BOD. Dissolved oxygen in the water would also decrease significantly. The spatial influence extends from the discharge point to Nam Trieu estuary, inside Cam, Bach Dang rivers, and Cat Hai coastal area
An improved performance routing protocol based on delay for MANETs in smart cities
Mobile ad-hoc networks (MANETs) is a set of mobile devices that can self-configuration, self-established parameters to transmission in-network. Although limited inability, MANETs have been applied in many domains to serve humanity in recent years, such as disaster recovery, forest fire, military, intelligent traffic, or IoT ecosystems. Because of the movement of network devices, the system performance is low. In order to MANETs could more contribution in the future of the Internet, the routing is a significant problem to enhance the performance of MANETs. In this work, we proposed a new delay-based protocol aim enhance the system performance, called performance routing protocol based on delay (PRPD). In order to analyze the efficiency of the proposed solution, we compared the proposed protocol with traditional protocols. Experiment results showed that the PRPD protocol improved packet delivery ratio, throughput, and delay compared to the traditional protocols
Academic Anxiety of Vietnamese Secondary School Students as a Reason for Applying Online Learning
Academic anxiety is one of the major problems in student psychology across the world. It applies equally to students of all ages, from elementary school to college and university students. Research shows that learning online is an effective way to defuse feelings of academic anxiety. Elimination of anxiety is clearly visible regardless of age, gender, or prior online learning experience. The study aims to identify academic anxiety as one of the most important reasons for moving to online learning or blended learning in secondary school. The study investigated academic anxiety among secondary school students in Vietnam. After surveying 677 students in classroom learning, the results showed that 13.7% of secondary students suffered from frequent anxiety, and 3.0% of them suffered from very frequent anxiety. Lower anxiety was observed among students actively participated in-class activities, and students with excellent academic performance. These factors can be optimally enhanced through blended and online learning. There were no differences in academic anxiety among male and female students, urban and rural students. There was a moderate correlation between a student's anxiety level and pressure of the school, parental expectations, students' motivation for high performance, and especially, among students who have the melancholic temperament. And the influence of these negative factors can also be optimally reduced with the help of online learning. Regression model could provide useful suggestions for parents, teachers and students in reducing academic anxiety for students, including the use of full or blended online learning
Factors Affecting Consumers’ Impulsive Purchasing Behavior in Circle K Convenience Stores in Hanoi, Vietnam
Impulsive purchasing behavior has been observed as one of the important studies conducted by marketers and researchers, as impulse buying has become a prevalent phenomenon in every retail format. The study was conducted to assess factors affecting consumers’ impulsive purchasing behavior in Circle K convenience stores in Hanoi, Vietnam. After reviewing a group of previous studies, the authors indicated 05 factors that affected consumers' impulsive purchasing behavior including impulsiveness, instant gratification, visual appeal, promotions and money availability. The study had selected 05 experts in the field of economics to conduct the expert interview. Moreover, the research team had also handed out the questionnaire and received 310 observations. Specifically, Impulsiveness had the strongest influence on the impulsive purchasing behavior of Circle K’s consumers in Hanoi. Keywords: factors, Impulsive purchasing behavior, Circle K convenience stores DOI: 10.7176/JESD/14-8-03 Publication date: April 30th 2023
A Multi-Constraints Routing Scheme for MANET-assisted IoT in Smart Cities
The fifth-generation mobile network (5G) provides extreme throughput and extremely low latency, which enables the Internet of Things (IoT) era and a series of smart IoT ecosystems. The widespread equipping of Device-to-Device (D2D) modules for vehiculars allows transmitting directly between devices without relying on central devices such as access points or base stations. This is the foundation for the shaping of mobile ad hoc communications, so-called MANETs. The combination of MANETs and IoT technology has led to the development of MANET-assisted IoT applications, which offer unprecedented capabilities. However, due to the mobility of network nodes, routing is one of the main challenges in these networks. To address this problem, we propose a multi-constraints routing schema to enhance the performance of MANET-assisted IoT systems. Our simulation experiments show that the proposed solution significantly outperforms traditional routing solutions in terms of performance such as latency, packet delivery ratio, and throughput
Impact of sand mining on sediment transport and morphological change of Hai Phong coastal area
The paper presents the results of simulating the impact of sand mining on sediment transport and morphological change in Hai Phong coastal area based on Delft3D model. Scenario groups are established: Present scenarios without sand mining and simulated scenarios of the present sand mining (assuming 30% sand compared to plan). The scenario groups are calculated in the dry and rainy seasons for main wind directions (NE, SE, SW) in the case of moderate wind and strong wind. The results show that sand mining reduces sediment flow alongshore (2–81%) and seawards (5–83%). Besides, the increase in depth causes morphological change in this area: Rising the deposition rate (5–10 mm/month) at the sand mining locations; decreasing accretion rate and increasing the erosion rate in the neighboring areas of sand mining location
ARtVista: Gateway To Empower Anyone Into Artist
Drawing is an art that enables people to express their imagination and
emotions. However, individuals usually face challenges in drawing, especially
when translating conceptual ideas into visually coherent representations and
bridging the gap between mental visualization and practical execution. In
response, we propose ARtVista - a novel system integrating AR and generative AI
technologies. ARtVista not only recommends reference images aligned with users'
abstract ideas and generates sketches for users to draw but also goes beyond,
crafting vibrant paintings in various painting styles. ARtVista also offers
users an alternative approach to create striking paintings by simulating the
paint-by-number concept on reference images, empowering users to create
visually stunning artwork devoid of the necessity for advanced drawing skills.
We perform a pilot study and reveal positive feedback on its usability,
emphasizing its effectiveness in visualizing user ideas and aiding the painting
process to achieve stunning pictures without requiring advanced drawing skills.
The source code will be available at https://github.com/htrvu/ARtVista.Comment: CHI 202
Optimization of protein extraction from "Cam" rice bran by response surface methodology
"Cam" rice bran was considered a waste product from rice, which is rich in natural compounds and protein owing to its outstanding nutritional value. This study aimed to establish an optimization model for extracting protein from rice bran, with two responses: extraction yield (%) and protein content (%). The variable parameters included were pH (8.5-9.5), stirring time (3.5-4.5 h), and enzyme incubation temperature (85-95°C). The coefficient of determination for both models were above 0.95, indicating a high correlation between the actual and estimated values. The maximum extraction yield and protein content were achieved when the conditions were set at pH of 9.02, stirring time of 4.02 h, and extraction temperature of 90.6°C. Under these optimum conditions, the predicted protein extracted from rice bran was 43.03% (moisture <13.0%), with an extraction yield of 15.9%. The findings of this study suggested that this protocol can enhance the utilization of rice bran and might be employed on a large scale in the food industry to exploit the nutritional source
On how religions could accidentally incite lies and violence: folktales as a cultural transmitter
Folklore has a critical role as a cultural transmitter, all the while being a socially accepted medium for the expressions of culturally contradicting wishes and conducts. In this study of Vietnamese folktales, through the use of Bayesian multilevel modeling and the Markov chain Monte Carlo technique, we offer empirical evidence for how the interplay between religious teachings (Confucianism, Buddhism, and Taoism) and deviant behaviors (lying and violence) could affect a folktale’s outcome. The findings indicate that characters who lie and/or commit violent acts tend to have bad endings, as intuition would dictate, but when they are associated with any of the above Three Teachings, the final endings may vary. Positive outcomes are seen in cases where characters associated with Confucianism lie and characters associated with Buddhism act violently. The results supplement the worldwide literature on discrepancies between folklore and real-life conduct, as well as on the contradictory human behaviors vis-à -vis religious teachings. Overall, the study highlights the complexity of human decision-making, especially beyond the folklore realm
Effects of potassium dichromate on the survival and reproduction of Moina micrura Kurz. 1875 (Cladocera: Moinidae)
Today, heavy metal pollution is an urgent problem in the world including Vietnam. An analytical approach is very important to identify, assess and forecast environmental risks from toxic components, in which ecotoxicology is considered to be the optimal tool. We conducted a study on M. micrura in order to contribute the creation of a biological basis for the use of zooplankton as an early warning of the risk of water pollution. The results showed that M. micrura was isolated from 29/3 Park Lake, Da Nang City, central Vietnam. The acute toxicity test of potassium dichromate on M. micrura showed LC 50 at 12, 24 and 48 hr were 0.26, 0.15 and 0.08 mg.l-1 K2Cr2O7, respectively. EC 50 was 0.015 mg.l-1 K2Cr2O7 for egg parameter and 0.009 mg.l-1 K2Cr2O7for neonate parameter. The results of acute and chronic toxicity tests showed that M. micrura was more sensitive than D. magna, D. pulex and C. cornuta.
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