Fiscal Policy and Economic Growth: Threshold Regression Model Approach

Doan Van DINH 대한산업공학회 2022 Industrial Engineeering & Management Systems Vol.21 No.4

This study investigates countries’ optimal tax-to-GDP ratio threshold to explore whether exceeding the optimal threshold revenue tax-to-GDP ratio causes reduced GDP growth and compares the optimal threshold revenue tax of countries with the match solution. Apply threshold regression model, unit root test, and cointegration test to explore the impact of the tax revenue-to-GDP ratio on GDP growth, besides the data set is collected time series yearly from 1994 to 2020 in Vietnam, the USA, and South Africa to estimate the optimal threshold tax revenue. The tax revenue to GDP and GDP growth has a close related: South Africa, USA, and Vietnam are corresponding 49%, 58%, 46%, and countries’ optimal thresholds of tax revenue to GDP are corresponding 24%, 10.3 %, and 19%. All variables are sta-tionary at the first difference, that is, the lag after one year. In addition, the cointegration test shows that the relation-ship between Vietnam’s and the US’s tax-to-GDP variable and economic growth is the relationship in the long-run and that of South Africa is the relationship in the short term. The results appropriately support the fiscal policy. The study identifies issues for managers, investors to consider having a comprehensive solution among macro cosmic policies, tax policy, investment policy, and other policies to control and balance the relationship between tax revenue to GDP and GDP growth; and having appropriate policies to regulate funds to stimulate investment over the long term.

Impulse Response of Inflation to Economic Growth Dynamics: VAR Model Analysis

DINH, Doan Van Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.9

The study investigates the impact of inflation rate on economic growth to find the best-fit model for economic growth in Vietnam. The study applied Vector Autoregressive (VAR), cointegration models, and unit root test for the time-series data from 1996 to 2018 to test the inflation impact on the economic growth in the short and long term. The study showed that the two variables are stationary at lag first difference I(1) with 1%, 5% and 10%; trace test indicates two cointegrating equations at the 0.05 level, the INF does not granger cause GDP, the optimal lag I(1) and the variables are closely related as R2 is 72%. It finds that the VAR model's results are the basis to perform economic growth; besides, the inflation rate is positively related to economic growth. The results support the monetary policy. This study identifies issues for Government to consider: have a comprehensive solution among macroeconomic policies, monetary policy, fiscal policy and other policies to control and maintain the inflation and stimulate growth; set a priority goal for sustainable economic growth; not pursue economic growth by maintaining the inflation rate in the long term, but take appropriate measures to stabilize the inflation at the best-fitted VAR forecast model.

Public Debt Management and Economic Growth: VAR Model Approach

Doan Van Dinh 대한산업공학회 2023 Industrial Engineeering & Management Systems Vol.22 No.2

Optimal Inflation Threshold and Economic Growth: Ordinal Regression Model Analysis

DINH, Doan Van Korea Distribution Science Association 2020 The Journal of Asian Finance, Economics and Busine Vol.7 No.5

The study investigates the relationship between the inflation rate and economic growth to find out the optimal inflation threshold for economic growth. Therefore, this study applied an ordinary least square model (OLS) and the ordinal regression model, and collected the time-series data from 1996 to 2017 to test the relationship between inflation and economic growth in the short-term and long-term. The sample fits the model and is statistically significant. The study showed that 96.6% of correlation between inflation rate and economic growth are close and 4.5% of optimal inflation threshold is appropriate for economic growth. It finds that the optimal inflation threshold is base to perform economic growth, besides the inflation rate is positively related to economic growth. The results support the monetary policy appropriately. This study identifies issues for Government to consider: have a comprehensive solution among macroeconomic policies, monetary policy, fiscal policy and other policies to control and maintain the inflation and stimulate growth; have appropriate policies to regulate inflation to stimulate economic growth over the long term; set a priority goal for sustainable economic growth; not pursue economic growth by maintaining the inflation rate in the long term, but take appropriate measures to stabilize the inflation at the optimal inflation threshold.

Influence of Nitrogen Gas Flow on the Hardness and the Tribological Properties of a TiAlBN Coating Deposited by Using a Magnetron Sputtering Process

Van Duong Luong,Doan Dinh Phuong,Phan Ngoc Minh,문경일 한국물리학회 2017 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.70 No.10

With a view to improving the mechanical properties of coatings applied in the field of cutting tools and machine parts, the TiAlBN coatings were deposited by using direction-current (dc) magnetron sputtering with the various contents of nitrogen gas in an argon-nitrogen gas mixture. The structural characteristics of the coatings were determined by using X-ray diffraction, the friction coefficient, and the hardness and elastic modulus of the coatings were investigated by using a tribometer and nano-indentation. The surface morphologies and the roughnesses of the coatings were analyzed by using field emission scaning electron microscopy (FESEM) and atomic force microscopy (AFM). Additionally, the effects of nitrogen gas flow on the properties of the TiAlBN coatings were investigated. The structural characterization results revealed a typical face-centered cubic TiN structure with (111), (220), and (222) diffraction peaks. The strongest intensity in the (111) orientation was obtained for the coating prepared at a nitrogen gas flow of 4 sccm. For this kind of samples were obtained the highest values of the hardness and the stability, a low friction coefficient, and a smooth surface.

Effect of oxidation of SiC particles on mechanical properties and wear behavior of SiC_p/Al6061 composites

Van Trinh, Pham,Lee, Junho,Minh, Phan Ngoc,Phuong, Doan Dinh,Hong, Soon Hyung Elsevier 2018 JOURNAL OF ALLOYS AND COMPOUNDS Vol.769 No.-

<P><B>Abstract</B></P> <P>In this paper, oxidized-silicon carbide particle/aluminum 6061 (oxidized-SiC<SUB>p</SUB>/Al6061) composites were fabricated using a spark plasma sintering technique. The microstructure, mechanical properties, and wear behavior of oxidized-SiC<SUB>p</SUB>/Al6061 composites were investigated. The results revealed an improvement in interfacial bond strength between Al6061 and oxidized SiC<SUB>p</SUB> due to the formation of an MgAl<SUB>2</SUB>O<SUB>4</SUB> continuous phase and suppression of brittle Al<SUB>4</SUB>C<SUB>3</SUB> formation at the interfacial layer. Hardness (∼145 HV), ultimate tensile strength (∼226 MPa), and elongation (10.8%) were enhanced by 75%, 26%, and 32%, respectively, for the composite containing 1400°C-oxidized SiC<SUB>p</SUB>, compared with those reinforced with as-received SiC<SUB>p</SUB>. The friction coefficient and specific wear rate of oxidized-SiC<SUB>p</SUB>/Al6061 composites were reduced by 7% and 17%, respectively; this is attributable to the improved hardness and strength of the composite and the transition of wear mechanisms from a combination of adhesive and fatigue wear to abrasive wear. Quantitative correlations among yield strength, ultimate tensile strength, and interfacial bond strength in SiC<SUB>p</SUB>/Al6061 composites were analyzed for the first time.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Oxidized-SiC<SUB>p</SUB>/Al6061 composites were prepared by spark plasma sintering. </LI> <LI> Interfacial layer between oxidized-SiC<SUB>p</SUB> and Al6061 matrix was investigated. </LI> <LI> The interfacial bond strength between oxidized SiC<SUB>p</SUB> and Al6061 matrix was estimated. </LI> <LI> Mechanical properties and wear resistance of the composites were improved. </LI> <LI> New quantitative correlations among the strengths of the composites was analyzed. </LI> </UL> </P>

Luminescence Properties of Ba₃Si<SUB>6</SUB>O<SUB>12</SUB> N₂:Eu<SUP>2+</SUP> Green Phosphor

Van Duong Luong,Dinh Phuong Doan,Hong-Ro Lee 한국표면공학회 2015 한국표면공학회지 Vol.48 No.5

To fabricate white LED having a high color rendering index value, red color phosphor mixed with the green color phosphor together in the blue chip, namely the blue chips with RG phosphors packaging is most favorable for high power white LEDs. In our previous papers, we reported on successful syntheses of Sr₂-Si5N8:Eu<SUP>2+</SUP> and CaAlSiN₃ phosphors for red phosphor. In this work, for high power green phosphor, greenemitting ternary nitride Ba₃Si6O12N₂:Eu<SUP>2+</SUP> phosphor was synthesized in a high frequency induction furnace under N₂ gas atmosphere at temperatures up to 1400℃ using EuF₃ as a raw material for Eu<SUP>2+</SUP>dopant. The effects of molar ratio of component and experimental conditions on luminescence property of prepared phosphors have been investigated. The structure and luminescence properties of prepared Ba₃Si6O12N₂:Eu<SUP>2+</SUP> phosphors were investigated by XRD and photoluminescence spectroscopy. The excitation spectra of Ba₃Si6O12N₂:Eu<SUP>2+</SUP> phosphors indicated broad excitation wavelength range of 250 - 500 nm, namely from UV to blue region with distinct enhanced emission spectrum peaking at ≈ 530 nm.

Access to Anti-smoking Information among School Children and its Potential Impact on Preventing Smoking Initiation: Results from the Global Youth Tobacco Use Survey (GYTS) 2014 in Viet Nam

Hoang, Van Minh,Kim, Bao Giang,Phan, Thi Hai,Trinh, Dinh Hoang,Doan, Thu Huyen,Luong, Ngoc Khue,Nguyen, Thuy Linh,Nguyen, Tuan Lam,Pham, Thi Quynh Nga Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.no.sup1

Scientific evidence on all aspects of smoking amongst youth is very important for designing appropriate interventions to reduce smoking among this vulnerable population. This paper describes current access to anti-smoking information among school children aged 13 to 15 years in Vietnam in 2014 and examines its potential impact on preventing smoking initiation. The data used in this paper were obtained from the 2014 Global Youth Tobacco Survey (GYTS) in Vietnam. Students were asked questions about their level of awareness of anti-smoking information from various sources in the past 30 days and about lessons in school regarding the dangers of tobacco use during the last 12 months. Those who have never smoked were asked "whether or not they thought about avoiding cigarettes because of health warnings on cigarette packages" and answers were analyzed in combination with data on access to anti-smoking information from other sources. The prevalence of exposure to antismoking campaigns was high among school children in Viet Nam: 55.3% of current smokers reported thoughts of smoking cessation because of health warnings on cigarette packages; 60.5% of never smokers avoided initiating smoking because of the same health warnings. The potential impact of graphic health warnings to prevent school-aged children from smoking initiation would be stronger if there was concurrent access to anti-smoking programs on the dangers of tobacco use in schools. However, school education for tobacco prevention and control has not been as strong as expected. A more comprehensive school curriculum on tobacco prevention and control is recommended to reinforce antismoking messages among school children.

An effective combination of reusable Pd@MOF catalyst and deep eutectic solvents for high-performance C–C coupling reaction

Minh-Huy Dinh Dang,Trang Thi Thu Nguyen,Bao Quang Gia Le,Linh Ho Thuy Nguyen,Ngoc Xuan Dat Mai,My Van Nguyen,Phuong Hoang Tran,Tan Le Hoang Doan 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.111 No.-

Pd-incorporated Zr-based metal–organic framework containing sulfone groups, named Pd(II)BUT-11, wassuccessfully prepared by dispersing the sulfone-functionalized MOF in Pd(OAc)2 solution. X-ray diffraction,scanning electron microscopy, N2 isotherm sorption, X-ray photoelectron spectroscopy, and thermogravimetricanalysis were applied to determine the features of the Pd-incorporated MOF. In the catalyticstudies, Pd(II)@BUT-11 was shown to be an efficient heterogeneous catalyst for synthesizing various stilbenederivatives via the cross-coupling Heck reaction with DABCO-derived deep eutectic solvent (DES) asa green solvent. Notably, the catalyst and the solvent could be recovered and reused, with their activityand structure remaining stable throughout several trials. The method provides an alternative solution tothe conventional catalysts and solvents, resulting in a green and efficient stilbene synthesis process. Furthermore, the stilbenes were separated by extraction with ethyl acetate due to the low solubility ofDES with this solvent.

The Relationship Between Chromium Content and Erosion-Corrosion Resistance of Fe-Cr-C Alloy System

Hue, Nguyen Viet,Phuong, Doan Dinh,Tich, Nguyen Van,Binh, Hoang Thi 한국부식방식학회 2002 Corrosion Science and Technology Vol.31 No.1

In order to determine the influence of chromium on erosian-comsian coefficient of alloy in acid media, experiments were performed with chromium content in the range of 12-33% in different typical erosion-corrosion environments such as solution of sand, solution of sand with free acid in pH 2-7. The erosion-corrosion coefficient was evaluated by Apparatus for abrasion-corrosion testing. Wear coetr-icient, K, was calculated by formula: K=ΔMetalon/ΔMalloy Testing results were showed that the alloy with composition (%): Cr=28-30; C=1.8-2.0; Mn=2.5 - 3.0; is the optimum for manufacturing details resistant erosion-corrosion in media upto pH=2-3. This alloy is used successfully to produce details for sand-pumps, minerals processing cyclones.