Elasticity of Market Demand between Modes of Transport in Vietnam by Price and Income

Quang Dung Truong,Hai Quang Nguyen,Dang Khoa Tran 중앙대학교 경제연구소 2020 Journal of Economic Development Vol.45 No.1

This study aims to determine the demand elasticity of passenger and freight transport market between different modes of transport in Vietnam by income, by price and by the price of substitute mode of transport (cross price). Upon consideration of the theoretical basis and inheriting the results of previous studies, this study applies a non-linear model to estimate the elasticity coefficients of demand. The analysis of the data for a 16-year period from 2001 to 2016 in Vietnam shows that as a general rule, the average per capita income is a factor that positively influences the transport market demand of different modes of transport. Freight rates, as a general rule, have an opposite effect on passenger transportation by waterway, freight transportation by road, by waterway and by air. Demand is greatly affected by the cross price in the freight transportation by air. The outcome of the research serves as a basis to propose business implications for executive management to make appropriate policies for each mode of transport and to create harmonization of all modes of transport.

Synthesis of Nano Titanium Dioxide and Its Application in Photocatalysis

Truong Van Chuong,Le Quang Tien Dung,Dinh Quang Khieu 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.52 No.5

This paper presents a simple way to synthesize titaniumdioxide nanotubes by using a microwave- assisted reaction of TiO2 particles and NaOH solution. The main advantage of the introduction of microwave into the reaction system is the extremely rapid kinetics for synthesis. This method is simple and easy to reproduce. Structural and microstructural characterizations of titania nanotubes were accomplished using X-ray diffraction (XRD), scanning-electron microscopy (SEM) and transmission-electron microscopy (TEM) techniques. The specific surface area was calculated using the Brunauer-Emmett-Teller model and was found to be 52 m2/g. A high photocatalysis of our TiO2 nanotubes was obtained. This paper presents a simple way to synthesize titaniumdioxide nanotubes by using a microwave- assisted reaction of TiO2 particles and NaOH solution. The main advantage of the introduction of microwave into the reaction system is the extremely rapid kinetics for synthesis. This method is simple and easy to reproduce. Structural and microstructural characterizations of titania nanotubes were accomplished using X-ray diffraction (XRD), scanning-electron microscopy (SEM) and transmission-electron microscopy (TEM) techniques. The specific surface area was calculated using the Brunauer-Emmett-Teller model and was found to be 52 m2/g. A high photocatalysis of our TiO2 nanotubes was obtained.

Parametric Study on Aerodynamic Performance of a Single-stage Transonic Axial Compressor with Recirculation-bleeding Channels

Ky-Quang Pham,Quang-Hai Nguyen,Tien-Dung Vuong,Cong-Truong Dinh 한국유체기계학회 2020 International journal of fluid machinery and syste Vol.13 No.2

This paper investigates a novel casing treatment method, called recirculation-bleeding channels, which combine a recirculation channel with additional bleeding channels. The system consists of 36 channels distributed around the blades and located on rotor shroud surface of a single-stage transonic axial compressor. This study focuses on its effects on aerodynamic performance of a single-stage transonic axial compressor, NASA Stage 37. Validation of numerical model of NASA Stage 37 was performed using experimental data for the single-stage transonic axial compressor. A common drawback of flow recirculation and air bleeding is the reduction in efficiency; however, numerical results showed that with the presence of recirculation-bleeding channels, both stall margin and adiabatic efficiency of the single-stage transonic axial compressor were increased as compared to the smooth casing with small penalty in pressure ratio. A parametric study of the recirculation-bleeding channels was performed for six geometric parameters. With recirculation-bleeding channels, the compressor could reach the stall margin of 13.85% at maximum while still retaining an increase in peak adiabatic efficiency. It is also showed that proper adjustments of the channels design can eliminate the deficiency in pressure ratio at peak efficiency condition.

The Relationship between Corporate Social Responsibility and Customer Purchase Intention: Empirical Evidence from Vietnam

Thang Quang TRAN,Ninh Truong Thi THUY,Dung Viet PHAM 한국유통과학회 2022 The Journal of Asian Finance, Economics and Busine Vol.9 No.5

Corporate social responsibility is becoming increasingly important to organizations, and it has received a lot of attention from the general public and marketing academics. This study aimed to look at the many aspects of corporate social responsibility and see how brand reputation and brand love play a role in the relationship between corporate social responsibility and customer purchase intent. To reach the end, this research applied the theory of social exchange and corporate social responsibility to explain the relationship between the variables. The Partial Least Squares was applied to analyze data collected from survey questionnaires in the Hanoi market (Vietnam) to test the proposed hypothesis. The study resulted in 239 valid survey questionnaires which can be used to test hypotheses by applying SmarPLS software. The results indicated that there are three key elements of corporate social responsibility from customers’ perspectives: responsibility to customers, responsibility to the environment, and responsibility to the community. Interestingly, brand reputation and brand love contribute as mediating roles in the correlation between corporate social responsibility and customer purchase intention. Finally, the authors discussed the findings and the implications of this research in both theoretical and practical aspects, as well as the limitations that future research can focus on.

A novel control method to maximize the energy-harvesting capability of an adjustable slope angle wave energy converter

Tri, Nguyen Minh,Truong, Dinh Quang,Thinh, Do Hoang,Binh, Phan Cong,Dung, Dang Tri,Lee, Seyoung,Park, Hyung Gyu,Ahn, Kyoung Kwan Elsevier 2016 RENEWABLE ENERGY Vol.97 No.-

<P><B>Abstract</B></P> <P>This paper introduces a novel control approach to maximizing the output energy of an adjustable slope angle wave energy converter (ASAWEC) with oil-hydraulic power take-off. Different from typical floating-buoy WECs, the ASAWEC is capable of capturing wave energy from both heave and surge modes of wave motions. For different waves, online determination of the titling angle plays a significant role in optimizing the overall efficiency of the ASAWEC. To enhance this task, the proposed method was developed based on a learning vector quantitative neural network (LVQNN) algorithm. First, the LVQNN-based supervisor controller detects wave conditions and directly produces the optimal titling angles. Second, a so-called efficiency optimization mechanism (EOM) with a secondary controller was designed to regulate automatically the ASAWEC slope angle to the desired value sent from the supervisor controller. A prototype of the ASAWEC was fabricated and a series of simulations and experiments was performed to train the supervisor controller and validate the effectiveness of the proposed control approach with regular waves. The results indicated that the system could reach the optimal angle within 2s and subsequently, the output energy could be maximized. Compared to the performance of a system with a vertically fixed slope angle, an increase of 5% in the overall efficiency was achieved. In addition, simulations of the controlled system were performed with irregular waves to confirm the applicability of the proposed approach in practice.</P> <P><B>Highlights</B></P> <P> <UL> <LI> This paper proposes a novel energy maximization algorithm of a sliding-buoy wave energy converter (SBWEC). </LI> <LI> An efficiency optimization mechanism is designed and integrated into the SBWEC. </LI> <LI> The control logic is based on a learning vector quantitative neural network for classifying the wave information. </LI> <LI> The effectiveness of the proposed approach is verified through both simulations and experiments. </LI> </UL> </P>

The Factors Affecting Passenger Satisfaction with Short-Range Air Transport Services: Approaches to Value Chain in the Case of Vietnam Airlines

Dang Khoa Tran,Quang Dung Truong 중앙대학교 경제연구소 2020 Journal of Economic Development Vol.45 No.1

Passenger satisfaction with flights is an essential factor that affects their loyalty and enables air-carriers to stabilize their market share, enhance sales efficiency in a highly competitive airline marketplace nowadays. This research aims to analyze the factors affecting passenger satisfaction towards short distance flights carried out by Vietnam Airlines. The research findings will lay the foundation for shaping up the business strategies for air carriers, especially for Vietnam Airlines to enhance passenger satisfaction level with their flights.

Effects of non-vertical linear motions of a hemispherical-float wave energy converter

Do, Hoang-Thinh,Dinh, Quang-Truong,Nguyen, Minh-Tri,Phan, Cong-Binh,Dang, Tri-Dung,Lee, Seyoung,Park, Hyung-Gyu,Ahn, Kyoung-Kwan Elsevier 2015 Ocean engineering Vol.109 No.-

<P><B>Abstract</B></P> <P>The hydraulic power-take-off mechanism (HPTO) is one of the most popular methods in wave energy converter (WECs). However, the conventional HPTO with only one direction motion has some drawbacks which limit its power capture capability. This paper proposes an <I>adjustable slope angle wave energy converter</I> (ASAWEC) and investigates the effect of slope angle on the performance of the proposed wave energy converter to find the optimal slope angle with the purpose to increase the power capture capability as well as energy efficiency. A mathematical model of components from a floating buoy to a hydraulic motor was modeled. A small scale WEC test rig was fabricated to verify the power capture capability and efficiency of the proposed system throughout experiments.</P> <P><B>Highlights</B></P> <P> <UL> <LI> This paper proposed an adjustable moving angle wave energy converter (AMAWEC). </LI> <LI> Mathematical model of AMAWEC was presented and simulated. </LI> <LI> An AMAWEC test rig were fabricated to do the experiment in variety of wave conditions and moving angle in the water tank. </LI> <LI> The effect of moving angle on the performance of a wave energy converter was investigated to find the optimal moving angle in each wave condition. </LI> <LI> Finally, the effectiveness of AMAWEC has been verified by experimental results. </LI> </UL> </P>