Global exponential stability of a class of neural networks with unbounded delays

In this paper, the global exponential stability of a class of neural networks is investigated. The neural networks contain variable and unbounded delays. By constructing a suitable Lyapunov function and using the technique of matrix analysis, some new sufficient conditions on the global exponential stability are obtained.Досліджено глобальну експоненціальну стійкість одного класу нейронних сіток. Нейронні сітки містять змінні та необмежені загаювання. На основі побудови відповідної функції Ляпунова та техніки матричного аналізу отримано нові достатні умови глобальної експоненціальної стійкості

Topological Lifshitz phase transition in effective model of QCD with chiral symmetry non-restoration

The topological Lifshitz phase transition is studied systematically within an effective model of QCD, in which the chiral symmetry, broken at zero temperature, is not restored at high temperature and/or baryon chemical potential. It is found that during phase transition the quark system undergoes a first-order transition from low density fully-gapped state to high density state with Fermi sphere which is protected by momentum-space topology. The Lifshitz phase diagram in the plane of temperature and baryon chemical potential is established. The critical behaviors of various equations of state are determined.Comment: 8 pages, 10 figure

Investigate the effect of EGR stratergies on the HCCI engine's performance with N-heptane fuel injection

In this study, the effect of EGR strategies on the HCCI engine's performance is studied. A program was established to control the injection fuel and amount of exhaust gas recirculation on the HCCI engine. The results of the research show that when the EGR rate is greater than 30%, the engine operates stably according to the HCCI combustion characteristic at speeds lower than 2400 rpm. But when engine speeds are higher than 2400 rpm, the HCCI combustion characteristic is unstable; the torque and the indicator efficiency decrease rapidly. When the HCCI engine increases the EGR rate, the start of combustion is gradually later, the coefficient gradually decreases to close to the black smoke characteristic curve, the CO, HC, and CO2 emissions increase. The NOx emissions tend to increase when the EGR ratio increases from 0–25%, but the NOx decreases when the EGR rate is greater than 25%

SHEDDING TO GROW: THE COMING DOI MOI 2.0 IN VIETNAM’S FOREIGN POLICY

Purpose of the study: The purpose of this study is to revisit the characteristics of Vietnam’s foreign policy since its renovation in 1986, also known as Doi Moi, and explore its future trajectory in the coming decades. Methodology: This study employs a well-established analytical framework relying on the two-level game theory in foreign policy analysis which denotes that a state’s foreign policy is shaped by both external and domestic factors. Primary data are collected from a wide range of trusted resources and databases and communications of the authors with Vietnamese veteran diplomats and foreign policymakers. Main finding: This article finds that three decades since the launching of Doi Moi in 1986, fundamental principles of Vietnam’s foreign policy remains intact. Because both domestic and external foundations for the initial stage of renovation have fundamentally been replaced by new contexts, Hanoi will likely move towards the so-called Doi Moi 2.0 characterized by greater proactiveness and determination. Applications of this study: This study has implication for policymakers, scholars and experts in the disciplines and subfields of politics, international relations, foreign policy analysis given that Vietnam has been well known for its significant achievements in its diplomatic relations after the Cold War and it is playing a growing role in regional and international affairs. The originality of this study: This study makes an original contribution to the existing literature of Vietnam’s foreign policy because it digs into an issue where only a few numbers of scholars have touched upon and provides a comprehensive analysis of the factors influencing Hanoi’s mindset, shaping Vietnam’s national interests and formulating Vietnam’s foreign policy in the coming decades

Assessing Eutrophication in the Coastal Bay by ASSETS Index Model

Xuan Dai is a coastal bay in Phu Yen Province, Vietnam. The bay has an area of 80 km2 and a considerable depth from 8 to 18 m. This is an ecologically diverse area with great potential for aquaculture and fishing, which brings significant benefits to the people in the region. For years, the excessive development of aquaculture has enriched the water in the bay, resulting in mass deaths of lobsters. In this study, the ASSETS index model has been applied to Xuan Dai Bay to determine the trophic status and the natural and man-made processes related to eutrophication. The study results showed that the core zone of Xuan Dai Bay (CZ) was classified with a high influencing factor, with a high eutrophic condition, with a “no change” future outlook, and with a bad final overall ASSETS grade. Ky Lo Estuary (KLE) presents a low pressure, a low eutrophic condition, a “no change” future outlook, and a good final ASSETS index. These mean that CZ had a poor tropic status or the eutrophication happened in this system; whereas, KLZ presented a good tropic condition or no eutrophication. A basic management plan and early warning monitoring should take into consideration the condition of the water body to preserve the good tropic condition in KLZ, especially during dry seasons. For CZ, three groups of solutions have been proposed, including nutrient management, ecosystem restoration, and further researches. The results of the study also reveal the significance and benefit of applying integrated methods in water quality assessment and management in coastal zones. Deep understanding of water retention time, typology, nutrient loading, and the land/water uses of a system is the key factor for atrophic status management strategy

Strategic Risk Determinants Influencing Growth of SMEs: The Case of Vietnam

Risk is inherent in all business functions and in every kind of activities. This is especially true for small and medium sized enterprises (SMEs) that are most exposed to the harmful effects of the risks, due to limited resources and structural features. Therefore, this study is conducted for identifying the relationship and impact strategic risk determinants including Political risks, Technological risks, Social risks on the growth of 30 small and medium forest enterprises (SMFEs) in Dien Bien as the case study. Political risks, Technological risks, Social risks are independent variables and the growth of SMFEs is a dependent variable. Data were collected through the questionnaire survey and using mean, correlation and regression analysis for this paper. The results show that there is a statistically significant negative correlation between strategic risk determinants on SMFEs growth. Keywords: Political risks, Technological risks, Social risks, Growth, SME

Challenges And Opportunities For The Development Of Infrastructure After ‘Oda Graduation’ - Moving Towards Sustainable Development: Case Study Of Vietnam

The research on ODA will be focused on its relation to Goal 17, the Partnership, considered a major issue by the researchers, especially in the case of Vietnam as a developing economy. ODA was mainly used for investing in economic infrastructure when Vietnam witnessed a downfall in receiving financial aid due to its significant economic growth. ODA helped Vietnam transform from one of the world’s poorest nations into a lower middle-income country and soon, this is going to lead to the ‘ODA Graduation’. However, the process has just begun. The country is still in a process of industrialization and modernization and its socio-economic situation has not been stable or solid. By all means, ODA is not only a financial resource, it also helps the country to accomplish Sustainable Development Goals (SDGs) of the UN. ‘ODA Graduation’ means that the economy of Vietnam has faced certain challenges such as increasing pressure of outbound debts; raising impact on social development or imbalance between high capital recovery investments and public-services investments. However, ‘ODA Graduation’ has brought certain opportunities such as increasing Vietnam’s independence in capital mobilization, preventing the removal of tariffs barrier, reducing losses and waste of funds. This research gives recommendations for improving Vietnam’s economic situation and can help overcome the difficulties in the period of ‘ODA Graduation’