日本産植物フシグロSilene firma、クロタキカズラHosiea japonica およびベトナム産植物Heliciopsis terminalisの成分研究

広島大学(Hiroshima University)博士(薬科学)Doctor of Philosophy in Medicinal Sciencedoctora

CPSS : a flexible and efficient simulator for wormhole-routed multicomputers

In this thesis, we present the design and implementation of the Concordia Parallel Systems Simulator (CPSS), a simulator for wormhole-routed multicomputers. The ultimate purpose of the CPSS is to provide a parallel programming environment which allows users to study impacts of system and software factors on program performance and to locate performance bottlenecks in parallel programs. The major challenge in the design of the CPSS is to make a good tradeoff between the accuracy of simulation results and the feasibility of simulation time. The CPSS can accurately simulate a large range of regular topologies that represent the communication structures of most applications in scientific computations as well as the topologies of many large-scale wormhole-routed networks. Users are given the flexibility of changing communication and computation parameters as often as needed. This flexibility allows for thorough analyses of program performance under different sets of systems parameters, or on various multicomputer systems having different characteristics. The CPSS provides a rich, powerful and user-friendly set of correctness and performance debugging tools. Performance statistics at several levels of details are available for users to fine-tune their programs. To support efficient network communication, we also propose optimal program mappings specifically designed for wormhole-routed networks. Our theoretical work in program mapping on wormhole-routed networks aims at emphasizing the importance of good mappings on such networks. As wormhole routing has become more popular, network sizes are expanded, and communication overheads are reduced, good mappings are indispensable to ensure high performance of applications running on wormhole-routed networks

Consistency of control performance in 3d overhead cranes under payload mass uncertainty

The paper addresses the problem of effectively and robustly controlling a 3D overhead crane under the payload mass uncertainty, where the control performance is shown to be consistent. It is proposed to employ the sliding mode control technique to design the closed-loop controller due to its robustness, regardless of the uncertainties and nonlinearities of the under-actuated crane system. The radial basis function neural network has been exploited to construct an adaptive mechanism for estimating the unknown dynamics. More importantly, the adaptation methods have been derived from the Lyapunov theory to not only guarantee stability of the closed-loop control system, but also approximate the unknown and uncertain payload mass and weight matrix, which maintains the consistency of the control performance, although the cargo mass can be varied. Furthermore, the results obtained by implementing the proposed algorithm in the simulations show the effectiveness of the proposed approach and the consistency of the control performance, although the payload mass is uncertain. © 2020 by the authors. Licensee MDPI, Basel, Switzerland

Artificial Intelligence and Machine Learning for Green Shipping: Navigating towards Sustainable Maritime Practices

This paper aims to investigate the role that artificial intelligence (AI) plays in promoting sustainability in the marine industry. The report demonstrates the potential of AI-driven technology to improve vessel operations, decrease emissions, and promote environmental stewardship. This potential is shown by detailed examination of existing trends, problems, and possibilities. Several vital studies highlight the significance of policy interventions that encourage the use of artificial intelligence. These interventions include financial incentives, legal frameworks, and programs to increase capability. Throughout this work, the importance of the role that artificial intelligence plays in driving efficiency, safety, and sustainability is emphasized. This work also highlights the urgent need for action to address climate change and environmental degradation in the marine sector. The marine industry can lessen its carbon footprint, decrease pollution, and improve ecosystem health if it shifts to various alternative fuels, renewable energy sources, and technologies powered by artificial intelligence. At the end of this work, an appeal is made to policymakers, industry stakeholders, and technology providers, urging them to prioritize investments in artificial intelligence research and development and to create collaboration to speed up the transition to a marine sector that is more sustainable and resilient

Corporate governance and firm performance: Evidence from Vietnamese listed companies

The research aims to provide empirical evidence on the relationship between corporate governance and firm performance in Vietnam – a developing economy in Asia. It focuses on the corporate governance of Vietnamese listed companies with a data-set of the five-year period from 2011 to 2015. Vietnamese listed companies are governed and controlled by two boards, Board of Directors and Supervisory Board. The research investigates the impacts of directors’ and supervisors’ characteristics and ownership structure on firm performance. The outcomes reveal that most governance mechanisms employed by Vietnamese listed companies were not effective and had no effect on the companies’ performance, except for managerial ownership and Supervisory Board size. Specifically, management ownership and firm performance were negatively correlated. Additional analyses show a positive relationship between the number of supervisors and firm performance, which was measured by market-based measurement

A SURVEY OF THE ERRORS OF STUDENTS IN GRADES 10 AND 12 WHEN USING VIETA’S FORMULAS TO SOLVE THE ASSOCIATED MATHEMATICAL PROBLEMS

Vieta’s formulas have many applications in the general mathematics program in Vietnam. Indeed, they appear in many forms of mathematical problems, ranging from 9th, 10th and 12th grades. The complexity of the mathematical problems makes students commit many errors when using the Vieta’s formulas to solve them. The sample consisted of 246 students in grades 10 and 12, in which they addressed four questionnaires related to Vieta’s formulas. The results were quite unexpected because the errors of tenth graders also existed for 12th grade students for many different reasons.  Article visualizations

Economic policy uncertainty and corporate social responsibility: evidence from emerging countries

This study examines the impact of economic policy uncertainty on corporate social responsibility (CSR) performance using a panel dataset spanning from 2004 to 2021 across six emerging countries within Southeast Asia. We find a negative association between country-level economic policy uncertainty and firms’ CSR performance, particularly in terms of environmental and social indicators. Our findings remain robust across various robustness analyses and after addressing endogeneity concerns. Further, our study sheds light on how country-level policy uncertainty influences firms’ sustainability investments across different sectors. Specifically, firms in the Consumer Discretionary, Basic Materials and Real Estate sectors experience adverse effects from increased economic uncertainty, whereas those in the Health Care sector demonstrate a positive correlation. The study suggests that policymakers and firm managers should address economic policy uncertainty to enhance CSR performance and sustainability investments across industries

Covid-19 Pandemic and Performance of Economic Sectors in Vietnam

Purpose of the paper: This study aims to consider the Covid impact on stock – price volatility of different industry groups in Vietnam by using the M-GARCH model

Covid-19 Pandemic and Performance of Economic Sectors in Vietnam

Purpose of the paper: This study aims to consider the Covid impact on stock – price volatility of different industry groups in Vietnam by using the M-GARCH model

Research on manufacturing dry mixed cement mortar with high compressive strength, high flexural strength, low shrinkage and high watertightness for restoration of damaged hydraulic structures in Vietnam

Using normal materials to manufacture the mixed mortar is necessary for restoration of hydraulic structures in Vietnam. It will salvage the materials and decreases the cost price of the mortar. In this research, we used cement made in Vietnam (Chinfon - Haiphong cement), natural sand (Lo River sand), polymer acrylic and high range water reducing (of SIKA company)' with proportion 1 : 3 : 0.03 : 0.003 by weight. The water to cement ratio is 0.5, which always ensure the compressive strength of mortar more than 40 MPa and small shrinkage, good watertightness, and high adhesion. That is suitable for the restoration of concrete structures in general and hydraulic structures in particular of Vietnam. The dry mixed mortar is manufactured and in bag of 15±0.5 kg weight