JUNIOR SCHOOL TEACHERS’ OPINIONS ON TEACHING TOPIC “TRAPEZOID” BY DISCOVERY LEARNING: THE INVESTIGATION IN DONG THAP PROVINCE, VIETNAM

Discovery learning is a method of inquiry-based instruction, in discovery learning, learners have opportunities to discover facts and relationships for themselves. In Vietnam, this method was approached from many decades ago. The paper will present the results of the investigating mathematics teachers’ opinions on the use of discovery learning in teaching geometry in junior schools of Vietnam in the case of instructing topic “trapezoid”.  Article visualizations

Limiting Reinforcement Ratios for Hybrid GFRP/Steel Reinforced Concrete Beams

In this work, a theoretical approach is proposed for estimating the minimum and maximum reinforcement ratios for hybrid glass fiber reinforced polymer (GFRP)/steel-reinforced concrete beams to prevent sudden and brittle failure as well as the compression failure of concrete before the tension failure of reinforcements. Equilibrium equations were used to develop a method for determining the minimum hybrid GFRP/steel reinforcement ratio. A method for determining the maximum hybrid GFRP/steel reinforcement ratio was also developed based on the equilibrium of forces of the balanced failure mode. For estimating the load-carrying capacity of concrete beams reinforced with hybrid GFRP/steel, less than the minimum and more than the maximum reinforcement ratio is recommended. Comparisons between the proposed expressions, experimental data, and available test results in the literature shows good agreement between the theoretical and experimental data, with a maximum discrepancy of 7%

A Case Study of BIM Application in a Public Construction Project Management Unit in Vietnam: Lessons Learned and Organizational Changes

Public construction projects in Vietnam are managed by project management units (PMUs). A PMU should consist of the board of directors, a project office, functional and project executive departments. Functional departments are in charge of investor’s responsibilities, while project executive departments are in charge of project execution. This paper discusses the practice of BIM adoption in a case study of a PMU (SPMB) in a public project. Lessons learned include the fact that, while BIM could provide certain benefits to the project, it also extended the project's duration and increased project costs. The SPMB, previously departmentalized by project phases, has changed its organizational structure by establishing a task group made up of professionals from various project executive departments, leading directly by the SPMB leaders, to address BIM issues, though only some basic uses of BIM have been applied. The functions of the project executive departments have also been adjusted due to the application of a new procurement form and the emergence of new processes, and the requirements for a new type of capability (BIM). Subsequently, other elements of the organizational design have been changed accordingly. The lessons learned contribute to the current understanding that PMUs need substantially organizational restructuring for BIM implementation effectively and efficiently while also well-prepared for negative impacts

A segmentation method for shared protection in WDM networks

Shared link and shared path protections have been recognized as preferred schemes to protect traffic flows against network failures. In recent years, another method referred to as Shared Segment Protection has been studied as an alternative solution for protection. This method is more flexible and efficient in terms of capacity utilization and restoration time. However, to our best knowledge, this method has mostly been studied in dynamic provisioning scenarios in which searching for restoration paths is dynamically performed after a failure has occurred. In this paper, based on the path segmentation idea, we propose a method to generate good candidate routes for traffic demands in static provisioning. These candidates are used as input parameters of an Integer Linear Programming (ILP) model for shared backup protection. Numerical results show that the capacity efficiency resulting from these candidates is much better than the best known Shared Backup Path Protection (SBPP) schemes. In addition, although the restoration time of our scheme is a little bit longer than those implementing link protection, it is still faster than path protection schemes

Revisiting LARS for Large Batch Training Generalization of Neural Networks

LARS and LAMB have emerged as prominent techniques in Large Batch Learning (LBL), ensuring the stability of AI training. One of the primary challenges in LBL is convergence stability, where the AI agent usually gets trapped into the sharp minimizer. Addressing this challenge, a relatively recent technique, known as warm-up, has been employed. However, warm-up lacks a strong theoretical foundation, leaving the door open for further exploration of more efficacious algorithms. In light of this situation, we conduct empirical experiments to analyze the behaviors of the two most popular optimizers in the LARS family: LARS and LAMB, with and without a warm-up strategy. Our analyses give us a comprehension of the novel LARS, LAMB, and the necessity of a warm-up technique in LBL. Building upon these insights, we propose a novel algorithm called Time Varying LARS (TVLARS), which facilitates robust training in the initial phase without the need for warm-up. Experimental evaluation demonstrates that TVLARS achieves competitive results with LARS and LAMB when warm-up is utilized while surpassing their performance without the warm-up technique

Possible Impact from Foreign Bank Presence to the Performance of Local Commercial Banks in Vietnam

Research on the impact of the presence of foreign banks on the domestic banking industry in particular is a popular topic for policy implications. The paper examines whether the presence of foreign banks improves the performance of domestic commercial banks in Vietnam. On the sample of 26 domestic commercial banks and 9 fully foreign-owned banks in Vietnam in the period 2009-2018, the research result shows that the presence of foreign banks reduces the profitability of domestic commercial banks, whereas does not have any impact on their operating costs, showing that the combination of spillover effects and competition effects has not caused a positive impact on Vietnamese banking industry. This result leads to policy implications that competition and the introduction of substitute products should be promoted, in order to make good use of the benefits of the entry of foreign banks. Keywords: foreign bank presence, bank performance, spillover effect, competition effect. JEL Classifications: G21, G34 DOI: https://doi.org/10.32479/ijefi.929