• The Journal of Asian Finance, Economics and Business
• /
• v.8 no.2
• /
• pp.175-182
• /
• 2021

The purpose of this study is to propose policy implications for improving the efficiency of corporate income tax management in Vietnam, by analyzing the study factors affecting the efficiency of corporate income tax management (evidence from Mekong Delta provinces, Vietnam). This study used a primary data collection method and collected data of 329 enterprises, including 49 joint-stock companies and 280 limited liability companies in 3 provinces - Tra Vinh province, Soc Trang province, and Ben Tre province. By using the binary regression method, the author discovered eight factors affecting the efficiency of corporate income tax management in the Mekong Delta region such as the time of operation of the enterprises, type of business, gender, business results, tax amount temporarily paid, compliance with tax policies, business scale, and tax debt ratio. From the above research results, the author proposes policies to support Tax Departments to improve the efficiency of corporate income tax management in the Mekong Delta region in the future. These policies include - for further promoting the tax policy propaganda to enterprises, tax authorities need to promptly handle tax arrears, enhance the inspection of tax debt enterprises, and focus on the business models, gender, age of the business owners, etc.

• Journal of Ecology and Environment
• /
• v.43 no.2
• /
• pp.161-182
• /
• 2019

Quantifying the amount of carbon pools in forest ecosystems enables to understand about various carbon pools in the forest ecosystem. Therefore, this study was conducted in the Chilimo dry afromontane forest to estimate the amount of carbon stored. The natural forest was stratified into three forest patches based on species composition, diversity, and structure. A total of 50 permanent sample plots of 20 m × 20 m (400 ㎡ ) each were established, laid out on transects of altitudinal gradients with a distance of 100 m between plots. The plots were measured twice in 2012 and 2017. Tree, deadwood, mineral soil, forest floor, and stump data were collected in the main plots, while shrubs, saplings, herbaceous plants, and seedling data were sampled inside subplots. Soil organic carbon (SOC %) was analyzed following Walkely, while Black's procedure and bulk density were estimated following the procedure of Blake (Methods of soil analysis, 1965). Aboveground biomass was calculated using the equation of Chave et al. (Glob Chang Biol_20:3177-3190, 2014). Data analysis was made using RStudio software. To analyze equality of means, we used ANOVA for multiple comparisons among elevation classes at α = 0.05. The aboveground carbon of the natural forest ranged from 148.30 ± 115.02 for high altitude to 100.14 ± 39.93 for middle altitude, was highest at 151.35 ± 108.98 t C ha^-1 for gentle slope, and was lowest at 88.01 ± 49.72 t C ha^-1 for middle slope. The mean stump carbon density 2.33 ± 1.64 t C ha^-1 was the highest for the middle slope, and 1.68 ± 1.21 t C ha^-1 was the lowest for the steep slope range. The highest 1.44 ± 2.21 t C ha^-1 deadwood carbon density was found under the middle slope range, and the lowest 0.21 ± 0.20 t C ha^-1 was found under the lowest slope range. The SOCD up to 1 m depth was highest at 295.96 ± 80.45 t C ha^-1 under the middle altitudinal gradient; however, it was lowest at 206.40 ± 65.59 t C ha^-1 under the lower altitudinal gradient. The mean ecosystem carbon stock density of the sampled plots in natural forests ranged from 221.89 to 819.44 t C ha^-1. There was a temporal variation in carbon pools along environmental and social factors. The highest carbon pool was contributed by SOC. We recommend forest carbon-related awareness creation for local people, and promotion of the local knowledge can be regarded as a possible option for sustainable forest management.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• 2008.11a
• /
• pp.772-775
• /
• 2008

According to Korean Ministry of Land, Transportation and Maritime Affairs, total national SOC(Social Overhead Capital) stock comes up to 500 billion dollars. Until now, although the construction of SOC is more important than the maintenance of them in Korea, it is necessary to introduce of valuation based total asset management concept in nowadays. In this paper describes problems of exsiting data collection method, needs of Information Technology and introduction of RFID/USN(Radio Frequency IDentification/Ubiquitous Sensor Network) in data collection stage.

• Journal of Korean Society of Transportation
• /
• v.23 no.2
• /
• pp.37-50
• /
• 2005

This study analyzes the effect of airport investment on GRDP(Gross Regional Domestic Product) using Regional Production Function with public investment on social infrastructure. Particularly it includes the spillover effect of airport investment on the economies of neighbor regions beyond border. We estimate regional production function with the independent variable of airport investment stock using panel data with regional cross-section and time-series data. In the analysis with aggregate data of all industries, it shows the positive relationship between airport investment and GRDP which implies the affirmative effect of airport investment on regional economy in the aspects of direct and indirect spill-over effects. On the contrary, the research results of each industry do not appear to be the same. With the different characteristics of each industry, the direct and indirect effect may not be the same and the SOC investment contributes to the restructuring of regional economy by altering the industrial organizations of any specific region and its neighbors.

• Journal of Ecology and Environment
• /
• v.46 no.4
• /
• pp.282-291
• /
• 2022

Background: The Arctic permafrost stores enormous amount of carbon (C), about one third of global C stocks. However, drastically increasing temperature in the Arctic makes the stable frozen C stock vulnerable to microbial decomposition. The released carbon dioxide from permafrost can cause accelerating C feedback to the atmosphere. Soil organic matter (SOM) composition would be the basic information to project the trajectory of C under rapidly changing climate. However, not many studies on SOM characterization have been done compared to quantification of SOM stocks. Thus, the purpose of our study is to determine soil properties and molecular compositions of SOM in four different Arctic regions. We collected soils in different soil layers from 1) Cambridge Bay, Canada, 2) Council, Alaska, USA, 3) Svalbard, Norway, and 4) Zackenberg, Greenland. The basic soil properties were measured, and the molecular composition of SOM was analyzed through pyrolysis-gas chromatography/mass spectrometry (py-GC/MS). Results: The Oi layer of soil in Council, Alaska showed the lowest soil pH and the highest electrical conductivity (EC) and SOM content. All soils in each site showed increasing pH and decreasing SOC and EC values with soil depth. Since the Council site was moist acidic tundra compared to other three dry tundra sites, soil properties were distinct from the others: high SOM and EC, and low pH. Through the py-GC/MS analysis, a total of 117 pyrolysis products were detected from 32 soil samples of four different Arctic soils. The first two-axis of the PCA explained 38% of sample variation. While short- and mid-hydrocarbons were associated with mineral layers, lignins and polysaccharides were linked to organic layers of Alaska and Cambridge Bay soil. Conclusions: We conclude that the py-GC/MS results separated soil samples mainly based on the origin of SOM (plants- or microbially-derived). This molecular characteristics of SOM can play a role of controlling SOM degradation to warming. Thus, it should be further investigated how the SOM molecular characteristics have impacts on SOM dynamics through additional laboratory incubation studies and microbial decomposition measurements in the field.