34 research outputs found
FACTORS INFLUENCING STUDENT SATISFACTION OF ONLINE LEARNING WITHIN A VIETNAMESE UNIVERSITY CONTEXT DURING THE COVID-19 PANDEMIC
Covid-19 created an unprecedented and severe crisis in Ho Chi Minh City. One of the more serious consequences of the Covid-19 pandemic has been social distancing. For the education system, the pandemic has directly affected students’ learning processes. Students have to study online at the begining of the new school year. This study aimed to investigate and clarify the impact of factors affecting the satisfaction of university students in Ho Chi Minh City in the online learning process. A total of 999 university students participated in a student satisfaction survey. The survey results show that most of students participating in the survey are satisfied with their online learning process. Many factors had a positive influence on students’ satisfaction in online learning, in which learning conferencing software had the greatest influence. Another finding was that there is a huge difference in students’ responses to learning conferencing software. The
study determined that the experience of using learning conferencing software influences student satisfaction, and it evaluated which learning conferencing software is the most optimal. Students satisfaction also varied depending on the number of academic years which the respondents had previously completed. This study’s findings are valuable for higher education administrators who want to improve student satisfaction with online
learning as it makes suggestions and recommendations to improve the quality of online learning and student satisfaction in Vietnam
The Relationship between Online Learning and Student Satisfaction with Training Quality in Private Universities during the COVID-19 Pandemic
This study aims to explore the relationship between the influential factors of online learning and the satisfaction of economics and business majors with the quality of their training in the context of the Covid-19 pandemic. A total of 900 students in private universities completed a questionnaire. The principal findings of this research are that the students are satisfied with their online learning and that learning conferencing software is the most important driving factor leading to the students’ satisfaction when compared with learning conditions and learning devices. Another interesting finding is that the experience of using learning conferencing software results in a slight difference in the students’ perceived level of satisfaction, adding that users with more than two years’ experience are more satisfied with their training quality than users with less than one year’s experience. However, the results also show that students want to switch to offline learning when the pandemic is over. This study should, therefore, be of value to higher education authorities wishing to understand their students’ perceptions of online learning. In addition, results from the study suggest more managerial approaches as well as improve the online teaching quality during the pandemic
Propagation of radiation source uncertainties in spent fuel cask shielding calculations
The propagation of radiation source uncertainties in spent nuclear fuel (SNF) cask shielding calculations is presented in this paper. The uncertainty propagation employs the depletion and source term outputs of the deterministic code STREAM as input to the transport simulation of the Monte Carlo (MC) codes MCS and MCNP6. The uncertainties of dose rate coming from two sources: nuclear data and modeling parameters, are quantified. The nuclear data uncertainties are obtained from the stochastic sampling of the cross-section covariance and perturbed fission product yields. Uncertainties induced by perturbed modeling parameters consider the design parameters and operating conditions. Uncertainties coming from the two sources result in perturbed depleted nuclide inventories and radiation source terms which are then propagated to the dose rate on the cask surface. The uncertainty analysis results show that the neutron and secondary photon dose have uncertainties which are dominated by the cross section and modeling parameters, while the fission yields have relatively insignificant effect. Besides, the primary photon dose is mostly influenced by the fission yield and modeling parameters, while the cross-section data have a relatively negligible effect. Moreover, the neutron, secondary photon, and primary photon dose can have uncertainties up to about 13%, 14%, and 6%, respectively
Measurement of neutron flux and gamma dose rate distribution inside a water phantom for Boron Neutron Capture Therapy study at Dalat Research Reactor
Exposure dose rate to the tumor and surrounding cells during neutron beam irradiation in Boron Neutron Capture Therapy (BNCT) comes not only from heavy charged particles produced from the 10B(n,α)7Li nuclear reaction, but also from neutron-induced reactions with other biological elements in living tissue, as well as from gamma rays leaked from the reactor core. At Dalat Research Reactor, Vietnam, the neutron and gamma dose rate distribution inside a water phantom were measured by using activation method and Thermoluminescent Dosimeter (TLD) detector, respectively. The results showed that effective thermal neutron dose rate along the center line of the water phantom had a maximum value of 479 mSv h-1 at 1 cm in phantom and then decreases rapidly to 4.87 mSv h-1 at 10 cm. The gamma dose rate along the center line of the water phantom also reach its maximum of 4.31 mSv h-1 at 1 cm depth and decreases to 1.16 mSv h-1 at 10 cm position. The maximum biological tumor dose rate was 1.74 Gy-eq h-1, not high enough to satisfy the treatment requirement of brain tumors. However, the results of this work are important in supporting of BNCT study in the upcoming stages at Dalat Research Reactor
Analysis of several VERA benchmark problems with the photon transport capability of STREAM
STREAM - a lattice transport calculation code with method of characteristics for the purpose of light water reactor analysis - has been developed by the Computational Reactor Physics and Experiment laboratory (CORE) of the Ulsan National Institute of Science and Technology (UNIST). Recently, efforts have been taken to develop a photon module in STREAM to assess photon heating and the influence of gamma photon transport on power distributions, as only neutron transport was considered in previous STREAM versions. A multi-group photon library is produced for STREAM based on the ENDF/B-VII.1 library with the use of the library-processing code NJOY. The developed photon solver for the computation of 2D and 3D distributions of photon flux and energy deposition is based on the method of characteristics like the neutron solver. The photon library and photon module produced and implemented for STREAM are verified on VERA pin and assembly problems by comparison with the Monte Carlo code MCS - also developed at UNIST. A short analysis of the impact of photon transport during depletion and thermal hydraulics feedback is presented for a 2D core also from the VERA benchmark. (C) 2022 Korean Nuclear Society, Published by Elsevier Korea LLC
Spatiotemporal evolution of SARS-CoV-2 Alpha and Delta variants during large nationwide outbreak of COVID-19, Vietnam, 2021
We analyzed 1,303 SARS-CoV-2 whole-genome sequences from Vietnam, and found the Alpha and Delta variants were responsible for a large nationwide outbreak of COVID-19 in 2021. The Delta variant was confined to the AY.57 lineage and caused >1.7 million infections and >32,000 deaths. Viral transmission was strongly affected by nonpharmaceutical interventions
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead