DISCOVERING ENGLISH PRONUNCIATION DIFFICULTIES AND STRATEGIES: A CASE AT TRA VINH UNIVERSITY

Pronunciation can take a crucial role in communication because unintelligible pronunciation may cause the conversers to misunderstand. Therefore, obtaining a clear accent plays a vital role in understanding the speakers' intended meaning. With this importance, the current study attempted to investigate the learners’ perception of English pronunciation and explore the pronunciation difficulties facing Vietnamese EFL students. Then, it also attempted to discover learners’ ideas on how they would like pronunciation to be instructed. In order to have the data for the investigation, the study applied the quantitative method by using a 5-point Likert scale to measure the level of students’ agreement in these three mentioned domains of investigation. A group of 49 second-year EFL students was employed at the School of Foreign Languages, School of Southern Khmer Language - Culture - Arts and Humanity, Tra Vinh University. They are studying English as a foreign language, and their major is English education. The results revealed that students agreed that learning pronunciation is difficult and strongly agreed with the ideas exhibited in the questionnaire on how pronunciation should be instructed. These results are used as recommendations for learning English pronunciation, and limitations of the study were also included.  Article visualizations

On the Interference Alignment Designs for Secure Multiuser MIMO Systems

In this paper, we propose two secure multiuser multiple-input multiple-output transmission approaches based on interference alignment (IA) in the presence of an eavesdropper. To deal with the information leakage to the eavesdropper as well as the interference signals from undesired transmitters (Txs) at desired receivers (Rxs), our approaches aim to design the transmit precoding and receive subspace matrices to minimize both the total inter-main-link interference and the wiretapped signals (WSs). The first proposed IA scheme focuses on aligning the WSs into proper subspaces while the second one imposes a new structure on the precoding matrices to force the WSs to zero. When the channel state information is perfectly known at all Txs, in each proposed IA scheme, the precoding matrices at Txs and the receive subspaces at Rxs or the eavesdropper are alternatively selected to minimize the cost function of an convex optimization problem for every iteration. We provide the feasible conditions and the proofs of convergence for both IA approaches. The simulation results indicate that our two IA approaches outperform the conventional IA algorithm in terms of average secrecy sum rate.Comment: Updated version, updated author list, accepted to be appear in IEICE Transaction

Comparision of both methods psi and curli: applied in solving multi-objective optimization problem of turning process

Solving a multi-objective optimization problem involves finding the best solution to simultaneously satisfy multiple predefined objectives. Currently, various mathematical methods are available for solving optimization problems in general, and multi-objective optimization in particular. The comparison of mathematical methods when addressing the same problem has been explored in numerous studies. In this study, let’s conduct a comparison of two multi-objective optimization methods: the PSI method and the CURLI method. These two methods were applied collectively to tackle a multi-objective optimization problem related to a turning process. Experimental data were borrowed from a previous study, and a total of sixteen experiments were conducted. Roughness average (Ra), Roundness Error (RE), Tool Wear (VB), and Material Removal Rate (MRR) were the four output parameters measured in each experiment. The objective of solving the multi-objective optimization problem was to identify an experiment among the sixteen existing experiments that simultaneously minimized the three parameters of Ra, RE, and VB while maximizing MRR. The optimal results determined using the PSI and CURLI methods were also compared with the optimal results obtained through other methods (COCOSO, MABAC, MAIRCA, EAMR and TOPSIS) in published documents. The comparison results indicate that the optimal experiment found using the CURLI method consistently matches that of other methods. In contrast, the optimal results obtained through the PSI method differ significantly from those obtained through other methods. The Spearman correlation ranking coefficient between CURLI and the five methods COCOSO, MABAC, MAIRCA, EAMR, and TOPSIS is very high, ranging from 0.9 to 1. In contrast, this coefficient is very small when comparing PSI with the aforementioned five methods, falling within the range of –0.6088 to –0.3706 in this case. Ultimately, this study concludes that the CURLI method is suiTable for solving the multi-objective optimization problem in the turning process, whereas the PSI method is deemed unsuitabl

HYBRID END-TO-END APPROACH INTEGRATING ONLINE LEARNING WITH FACE-IDENTIFICATION SYSTEM

To date, facial recognition has been one of the most intriguing, interesting research topics over years. It requires some specific face-based algorithms such as facial detection, facial alignment, facial representation, and facial recognition as well; however, all of these algorithms derive from heavy deep learning architectures that cause limitations for development, scalability, flawed accuracy, and deployment into publicity with mere CPU servers. It also calls for large datasets containing hundreds of thousands of records for training purposes. In this paper, we propose a full pipeline for an effective face recognition application which only uses a small Vietnamese celebrity dataset and CPU for training that can solve the leakage of data and the need for GPU devices. It is based on a face vector-to-string tokens algorithm then saves face’s properties into Elasticsearch for future retrieval, so the problem of online learning in Facial Recognition is also tackled. Comparison with another popular algorithm on the dataset, our proposed pipeline not only outweighs the accuracy counterpart, but it also achieves a very speedy time inference for a real-time face recognition application

Seawater desalination using air gap membrane distillation-an experimental study on membrane scaling and cleaning

The connection between operating temperature and membrane scaling/cleaning during an air gap membrane distillation (AGMD) process of seawater has been systematically elucidated in this study. Experimental and mathematically simulated data demonstrate the profound influences of feed salinity and membrane scaling on water flux at various operating temperatures. Feed salinity exerted significant impacts on water flux at high operating temperatures because of aggravated polarization effects. Membrane scaling and the subsequent membrane cleaning efficiency were also strongly affected by operating temperatures. Indeed, membrane scaling was more severe and occurred at a lower water recovery when operating at 60-50 °C (feed-coolant temperature) compared to that at 35-25 °C. Moreover, membrane cleaning with fresh water and vinegar was less effective for the membrane scaled at 60-50 °C compared to 35-25 °C. Finally, membrane cleaning using vinegar was much more efficient than fresh water. Given the availability of vinegar at household level, vinegar cleaning can potentially be a low cost and readily accessible approach for MD maintenance for small scale seawater desalination applications in remote coastal communities

Numerical and Experimental Study on the Grinding Performance of Ti-Based Super-Alloy

The experiments of the surface grinding of Ti-6Al-4V grade 5 alloy (Ti-64) with a resin-bonded cubic Boron Nitride (cBN) grinding wheel are performed in this research to estimate the influence of cutting parameters named workpiece infeed speed, Depth of Cut (DOC), cooling condition on the grinding force, force ratio, and specific energy. A finite element simulation model of single-grain grinding of Ti-64 is also implemented in order to predict the values of grinding forces and temperature. The experimental results show that an increase of workpiece infeed speed creates higher intensified cutting forces than the DOC. The grinding experiments under wet conditions present slightly lower tangential forces, force ratio, and specific energy than those in dry grinding. The simulation outcomes exhibit that the relative deviation of simulated and experimental forces is in the range of 1-15%. The increase in feed rate considerably reduces grinding temperature, while enhancement of DOC elevates the heat generation in the cutting zone

Réduction de modèles issus de la méthode PEEC pour la modélisation électromagnétique des interconnexions électriques

Le sujet de cette thèse traite de l'amélioration de la méthode PEEC inductive (permettant une modélisation des interconnexions électriques d'un point de vue électromagnétique basse fréquence) en employant une méthode de compression matricielle FMM. L'introduction de ces compressions entraîne des restrictions concernant les opérations algébriques autorisées, seule les opérations de type produit matrice - vecteur sont permises. L'objectif était de proposer des méthodes pour déterminer : Les courants en tout point du dispositif Des impédances équivalentes entre différents ports d'entrées-sorties. Le premier point a pu être traité en mettant en place une méthode originale de recherche d'un jeu d'équations indépendantes ainsi qu'un préconditionneur spécifique dans la phase de résolution compatible avec les méthodes de compression matricielle. Le second point a nécessité l'utilisation de méthode de réduction d'ordre à base de sous espace de Krylov afin de construire un développement limité des jeux d'impédance recherché. Ensuite, nous avons mis en place une technique de synthèse de circuit afin d'obtenir un circuit électrique simple permettant de modéliser le comportement du dispositif avec de simples éléments de type résistance, inductance (non couplée) et capacité. Cette démarche permet l'utilisation dans tous les simulateurs temporels et ainsi permet d'avoir une vision système légère du dispositif d'interconnexion électrique.This thesis deals with the improvement of the inductive PEEC method (for modelling electrical interconnections of low frequency) using the matrix compression Fast Multipole Method (FMM). The introduction of FMM leads to only algebraic operation of type matrix - vector product is permitted. The objective of this thesis was to propose some methods to determine: Currents at any point of the device The equivalent impedances between different input-output ports. The first point has been treated by introducing a novel method to determine a set of independent equations. The choice of iterative methods in solving linear system imposed on the establishment of a specific preconditioner compatible with matrix compression methods. The second point require to describe the Kirchoff law in the form of state space equation and to use model order reduction method based on Krylov subspace to compute Taylor series of impedance matrix. Once again, all the steps are necessary to be taked into account the use of matrix compression method FMM. Following our order reduction method, we implemented a circuit synthesis technique to obtain a simple electrical circuit which conserve the behavior of the device by simple elements like resistance, inductance (uncoupled) and capacity. This approach allows the reuse of reduction model in all time domain simulation software. For global system, it provides also a light model of electrical interconnection device.SAVOIE-SCD - Bib.électronique (730659901) / SudocGRENOBLE1/INP-Bib.électronique (384210012) / SudocGRENOBLE2/3-Bib.électronique (384219901) / SudocSudocFranceF

Embedding Sustainable Consumption into Higher Education in Vietnam

Changing in the way that human produces and consumes are indispensable to achieve sustainable consumption. All of the countries in developed economies, economies in transition and developing economies should promote sustainable consumption. This will require larger changes in society. Higher education plays a vital role in promoting understanding, awareness of professors, staff members and students of sustainable consumption. Through higher education, these people would be positively change their mind about this issue. National Economics University (NEU) is one of the leading university in economics in Vietnam as a case study. Students graduated from the university will be future experts, leaders and businessmen. After graduation, as academic citizens with acquainted knowledge and skills, they will influence the economic and social changes though their business and private purchasing habits and decisions. Using data from the University, this paper will reveal the current landscape of sustainable consumption at National Economics University through the years. In order to embed this issues into education, the university should incorporate sustainable consumption into the curriculum, create and implement a sustainability plan and adjust teaching method to encourage students asking questions, analyzing, thinking critically and making decisions toward sustainable consumption. Keywords: Embedding sustainable consumption, higher education DOI: 10.7176/EJBM/11-18-12 Publication date:June 30th 201