Purpose – The tourism industry service network (TISN) is considered to be one of the largest comp... more Purpose – The tourism industry service network (TISN) is considered to be one of the largest components of tourism in the modern Vietnamese economy. The Vietnam National Administration of Tourism (VNAT) is currently developing a long-term plan to diversify the country’s tourism industry and to improve the destination image of Vietnam. To successfully implement this plan, the Vietnamese tourism industry must employ effective promotional strategies. Design – This study designs to determine the necessity of measuring the effectiveness of the promotional activities of tourist destinations and to decide upon a promotional strategy that appropriately parallels the desired destination attributes and destination image. Methodology – This study proposes to address tourism promotional efficiency using the analytical hierarchy process (AHP) methodology, a decision-making method based on pairwise comparisons between criteria, and constructs an evaluation structure with criteria-associated weigh...
ABSTRACT The properites of the optimal and sub-optimal solutions to multiple-pass aeroassisted pl... more ABSTRACT The properites of the optimal and sub-optimal solutions to multiple-pass aeroassisted plane change were previously studied in terms of the trajectory variables. The solutions show the strong orbital nature. Then, it is proposed to obtain the variational equations of the orbital elements. We shall use these equations and the approximate control derived in Vinh and Ma (1990) to calculate the trajectories. In this respect, the approximate control law and the transversality condition are transformed in terms of the orbital elements. Following the above results, we can reduce the computational task by further simplification. Within omega and Omega being small and returning to the value of zero after each revolution, we neglect the equations for omega, and Omega. Also, since omega approximately equal to 0, that is alpha approximately equal to f, we can neglect the equation for the alpha and have only three state equations for the integration. Still the computation over several revolutions is long since it is performed using the eccentric anomaly along the osculating orbit as the independent variable. Here, we shall use the method of averaging as applied to the problem of orbit contraction to solve the problem of optimal plane change. This will lead to the integration of a reduced set of two nonlinear equations.
In the context of the long, complex disputes in Bien Dong (South China Sea) and the emergence of ... more In the context of the long, complex disputes in Bien Dong (South China Sea) and the emergence of the use of force risks therefor, a long term solution based on a system of approaches and measures on deferent diplomatic, economic, and legal levels must be available. On the legal level, the Article analyzes the main contents of the Arbitration Award in the Philippines v. China Case regarding the status of islands and other features and the China's unreasonable claim on the nine-dash line and its actions in the South China Sea. Since then, the Article suggests the comments on the effects and consequences of the Award in light of the general perception that this Award is an important victory of international law in general and of the Law of the Sea in particular, this also is the victory of the countries, including Vietnam against China's unjustified unilateral claims and acts in the South China Sea. Keywords: South China sea; the arbitration award on South China sea, legal stat...
Asymmetric infomation has caused difficulties for investors in the financial market when the ente... more Asymmetric infomation has caused difficulties for investors in the financial market when the enterprises have high competitiveness in the market but there are acts of using unusual capital structure. Investment decisions on the stock market of investors will be negatively affected by asymmetric information. In particular, the manufacturing enterprises have made an important contribution to Vietnam’s economic structure. Therefore, the authors conduct research to assess the impact of product market competition on the capital structure of manufacturing enterprises listed in the Vietnam stock market from 2010 to 2018. By analyzing panel data through the Generalized Method of Moments (GMM), the research results indicate: Competitiveness factors HHI has a negative impact on debt ratio (DR)—the results support the predation theory. When businesses are highly competitive, there will be a tendency to reduce the debt ratio. At the same time, the research results also show the variables ROA an...
International Journal of Economics and Finance, 2019
Vietnam is a country which has an attractive level of attracting foreign direct investment (Herea... more Vietnam is a country which has an attractive level of attracting foreign direct investment (Hereafter FDI) in the region with many preferential policies for investors. FDI attraction aims to help economic growth as well as increase the country's labour productivity. Therefore, the author conducted research to the impact of FDI and human capital on labor productivity of Vietnam. With data analysis techniques using ARDL model with data collected from 1990 to 2017, research result shows that FDI has a positive impact on labor productivity in short term and long term. The factor of university qualification (human capital) only has a positive impact on labor productivity in the long term.
This paper presents a new high-efficiency-high-step-up based converter integrating two stype DC-D... more This paper presents a new high-efficiency-high-step-up based converter integrating two stype DC-DC Boost and Flyback coupled magnetic converter with recovery stage dedicated to smart HVDC distributed architecture in renewable energy production systems. Appropriate duty cycle ratio assumes that the recovery stage work with parallel charge and discharge to achieve high step-up voltage gain. Besides, the voltage stress on the main switch is reduced with a passive clamp circuit and thus, low on-state resistance Rdson of the main switch can be adopted to reduce conduction losses. The circuit is simple to control. As a final point of this research, the simulation and the prototype investigational results are presented to demonstrate the effectiveness of this proposed converter.
Journal of the Astronautical Sciences, May 1, 1970
Optimum switching in minimum fuel, time-free impulsive planar transfer problem by primer vector c... more Optimum switching in minimum fuel, time-free impulsive planar transfer problem by primer vector concept
A generalized Yaroshevskii's system of equations is derived for analyzing ballistic entry at ... more A generalized Yaroshevskii's system of equations is derived for analyzing ballistic entry at supercircular speeds. By an artificial introduction of a small parameter, the nonlinear system can then be integrated by Poincare's method. It is pointed out that the second-order theory displays explicitly the influence of the ballistic coefficient, entry speed, and entry angle on exit conditions. The analytic solution is found to be in excellent agreement with the numerical solution. Using an explicit formula, the critical entry angle at which the vehicle fails to skip out can be predicted to within one hundredth of a degree.
Purpose – The tourism industry service network (TISN) is considered to be one of the largest comp... more Purpose – The tourism industry service network (TISN) is considered to be one of the largest components of tourism in the modern Vietnamese economy. The Vietnam National Administration of Tourism (VNAT) is currently developing a long-term plan to diversify the country’s tourism industry and to improve the destination image of Vietnam. To successfully implement this plan, the Vietnamese tourism industry must employ effective promotional strategies. Design – This study designs to determine the necessity of measuring the effectiveness of the promotional activities of tourist destinations and to decide upon a promotional strategy that appropriately parallels the desired destination attributes and destination image. Methodology – This study proposes to address tourism promotional efficiency using the analytical hierarchy process (AHP) methodology, a decision-making method based on pairwise comparisons between criteria, and constructs an evaluation structure with criteria-associated weigh...
ABSTRACT The properites of the optimal and sub-optimal solutions to multiple-pass aeroassisted pl... more ABSTRACT The properites of the optimal and sub-optimal solutions to multiple-pass aeroassisted plane change were previously studied in terms of the trajectory variables. The solutions show the strong orbital nature. Then, it is proposed to obtain the variational equations of the orbital elements. We shall use these equations and the approximate control derived in Vinh and Ma (1990) to calculate the trajectories. In this respect, the approximate control law and the transversality condition are transformed in terms of the orbital elements. Following the above results, we can reduce the computational task by further simplification. Within omega and Omega being small and returning to the value of zero after each revolution, we neglect the equations for omega, and Omega. Also, since omega approximately equal to 0, that is alpha approximately equal to f, we can neglect the equation for the alpha and have only three state equations for the integration. Still the computation over several revolutions is long since it is performed using the eccentric anomaly along the osculating orbit as the independent variable. Here, we shall use the method of averaging as applied to the problem of orbit contraction to solve the problem of optimal plane change. This will lead to the integration of a reduced set of two nonlinear equations.
In the context of the long, complex disputes in Bien Dong (South China Sea) and the emergence of ... more In the context of the long, complex disputes in Bien Dong (South China Sea) and the emergence of the use of force risks therefor, a long term solution based on a system of approaches and measures on deferent diplomatic, economic, and legal levels must be available. On the legal level, the Article analyzes the main contents of the Arbitration Award in the Philippines v. China Case regarding the status of islands and other features and the China's unreasonable claim on the nine-dash line and its actions in the South China Sea. Since then, the Article suggests the comments on the effects and consequences of the Award in light of the general perception that this Award is an important victory of international law in general and of the Law of the Sea in particular, this also is the victory of the countries, including Vietnam against China's unjustified unilateral claims and acts in the South China Sea. Keywords: South China sea; the arbitration award on South China sea, legal stat...
Asymmetric infomation has caused difficulties for investors in the financial market when the ente... more Asymmetric infomation has caused difficulties for investors in the financial market when the enterprises have high competitiveness in the market but there are acts of using unusual capital structure. Investment decisions on the stock market of investors will be negatively affected by asymmetric information. In particular, the manufacturing enterprises have made an important contribution to Vietnam’s economic structure. Therefore, the authors conduct research to assess the impact of product market competition on the capital structure of manufacturing enterprises listed in the Vietnam stock market from 2010 to 2018. By analyzing panel data through the Generalized Method of Moments (GMM), the research results indicate: Competitiveness factors HHI has a negative impact on debt ratio (DR)—the results support the predation theory. When businesses are highly competitive, there will be a tendency to reduce the debt ratio. At the same time, the research results also show the variables ROA an...
International Journal of Economics and Finance, 2019
Vietnam is a country which has an attractive level of attracting foreign direct investment (Herea... more Vietnam is a country which has an attractive level of attracting foreign direct investment (Hereafter FDI) in the region with many preferential policies for investors. FDI attraction aims to help economic growth as well as increase the country's labour productivity. Therefore, the author conducted research to the impact of FDI and human capital on labor productivity of Vietnam. With data analysis techniques using ARDL model with data collected from 1990 to 2017, research result shows that FDI has a positive impact on labor productivity in short term and long term. The factor of university qualification (human capital) only has a positive impact on labor productivity in the long term.
This paper presents a new high-efficiency-high-step-up based converter integrating two stype DC-D... more This paper presents a new high-efficiency-high-step-up based converter integrating two stype DC-DC Boost and Flyback coupled magnetic converter with recovery stage dedicated to smart HVDC distributed architecture in renewable energy production systems. Appropriate duty cycle ratio assumes that the recovery stage work with parallel charge and discharge to achieve high step-up voltage gain. Besides, the voltage stress on the main switch is reduced with a passive clamp circuit and thus, low on-state resistance Rdson of the main switch can be adopted to reduce conduction losses. The circuit is simple to control. As a final point of this research, the simulation and the prototype investigational results are presented to demonstrate the effectiveness of this proposed converter.
Journal of the Astronautical Sciences, May 1, 1970
Optimum switching in minimum fuel, time-free impulsive planar transfer problem by primer vector c... more Optimum switching in minimum fuel, time-free impulsive planar transfer problem by primer vector concept
A generalized Yaroshevskii's system of equations is derived for analyzing ballistic entry at ... more A generalized Yaroshevskii's system of equations is derived for analyzing ballistic entry at supercircular speeds. By an artificial introduction of a small parameter, the nonlinear system can then be integrated by Poincare's method. It is pointed out that the second-order theory displays explicitly the influence of the ballistic coefficient, entry speed, and entry angle on exit conditions. The analytic solution is found to be in excellent agreement with the numerical solution. Using an explicit formula, the critical entry angle at which the vehicle fails to skip out can be predicted to within one hundredth of a degree.
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Papers by Nguyen Truong Vinh