• The Journal of Asian Finance, Economics and Business
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• v.7 no.10
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• pp.581-589
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• 2020

Foreign factors play an important role in the socio-economic development of each country, in which foreign direct investment (FDI), foreign aid and exports of goods and services are always given top priority in undeveloped countries as well as developing countries. The purpose of this study is to examine the relationship between the various factors such as FDI, foreign aid, exports and economic growth in Vietnam. The empirical method employed secondary time-series data set during the period 1997-2018 to determine the impact of FDI, foreign aid and exports on economic growth in Vietnam by using a linear approach. For this study, data is collected from the World Bank and relevant agencies in Vietnam. An empirical model is built with a correlation and regression analysis between economic growth (GDP, current) and three independent variables (FDI, aid, exports of goods and services). The results show that the relationship between FDI (net inflows), aid, exports and GDP (current) has a positive effect at a 1% significance level. Based on these findings, the article recommends that Vietnam continues to seek effective solutions to maintain high economic growth rates by attracting FDI inflows, official development assistance (ODA), and increasing exports of goods and services.

• Journal of the Korean institute of surface engineering
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• v.56 no.1
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• pp.55-61
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• 2023

As a preliminary study to produce functional nanocomposites in a heat dissipation device, we performed the direct synthesis of carbon nanotubes (CNTs) on the surface of alumina (Al₂O₃) powders. A thermal chemical vapor deposition (TCVD) system was used to grow CNTs directly on the Al₂O₃ surface. In order to investigate the growth behavior of CNTs, we varied both furnace temperature of the TCVD ranging from 700 to 850 ℃ and concentration of the ferritin-dissolved DI solution from 0.1 to 2.0 mg/mL. From the previous results, the gas composition and duration time for CNT growth were fixed as C₂H₄ : H₂ = 30 : 500 (vol. %) and 10 min, respectively. Based on the analysis results, the optimized growth temperature and ferritin concentration were found to be 825 ℃ and 0.5 mg/mL, respectively. The obtained results could be adopted to achieve mass production of nanocomposites with heat dissipation functionality.

• Journal of the Korean institute of surface engineering
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• v.57 no.1
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• pp.22-30
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• 2024

This study reports a direct growth of carbon nanotubes (CNTs) on the surface of LiCoO₂ (LCO) powders to apply as highly efficient cathode materials in lithium-ion batteries (LIB). The CNT synthesis was performed using a thermal chemical vapor deposition apparatus with temperatures from 575 to 625 ℃. Ferritin molecules as growth catalyst of CNTs were mixed in deionized (DI) water with various concentrations from 0.05 to 1.0 mg/mL. Then, the LCO powders was dissolved in the ferritin solution at a ratio of 1g/mL. To obtain catalytic iron nanoparticles on the LCO surface, the LCO-ferritin suspension was dropped in silicon dioxide substrates and calcined under air at 550℃. Subsequently, the direct growth of CNTs on LCO powders was performed using a mixture of acetylene (10 sccm) and hydrogen (100 sccm) for 10 min. The growth behavior was characterized by scanning and transmission electron microscopy, Raman scattering spectroscopy, X-ray diffraction, and thermogravimetric analysis. The optimized condition yielding high structural quality and amount of CNTs was 600 ℃ and 0.5 mg/mL. The obtained materials will be developed as cathode materials in LIB.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.1
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• pp.83-88
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• 2014

This research was carried out to determine the characteristics of germination in relation to temperature, and seedling emergence and growth affected by soil moisture in forage millet. The seeds of forage millet could germinate at more than $15^{\circ}C$ at the rate of 0, 90.5, 97.3 and 96.8% respectively 10 days after seeding at 10, 15, 20 and $25^{\circ}C$. The result showed that the temperature needs to be $15^{\circ}C$ or more for the seeds to germinate. The effects of seeding depth on the growth characteristics and emergence of millet seed were investigated in waters and direct seeding methods by thoroughly mixing the seed and soil. In water treatment, the emergence rates were 3.7% at $15^{\circ}C$, 7.6% at $20^{\circ}C$, 6.3% at $25^{\circ}C$, while direct seeding treatment showed the emergence rates of 65.6, 75 and 71% at 15, 20 and $25^{\circ}C$, respectively. At 15, 20, and $25^{\circ}C$, seeds in water seeding could germinate at 0.5, 1.8, 1.5 cm of soil depth, while in direct seeding, they could germinate at the depth of 9.5, 10.0, 9.9 cm. When the initial growth characteristics of the seeds were investigated, there was positive correlation between seeding depth and mesocotyl length in both water and direct seed methods. Growth and development in terms of leaf age, root length, coleoptiles and mesocotyl length, and plant height were found maximum at 0.5 cm soil depth for water seeding, and 3-5 cm soil depth for direct seeding. Results showed that there were close relationship among temperature, soil depth and moisture acquiring methods, and the combination of these factors greatly affected the initial growth characteristics and development of millet seeds. It can be concluded that, to get good seedling stand and germination of millet seed, millet should grown in field condition at the depth of 0.5 cm or less for water seeding, and 3-5 cm for direct seeding method.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.4
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• pp.459-465
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• 1997

This experiment was conducted to compare the change of growth and canopy photosynthesis between transplanting and direct seeding on paddy surface in rice. Total tiller number by the early vegetative growth stage was significantly higher in the direct seeding flooded paddy surface, while it was reversed from later vegetative growth stage in terms of tillering ability per unit period. But total panicle number was higher in direct seeding on paddy surface. Leaf area index, nitrogen content in leaf blade and canopy photosynthetic ability at later vegetative growth stage were lower in direct seeding on flooded paddy surface than transplanting. Biological yield at harvest stge, leaf area index and conopy photosynthetic activity at heading stage were gradually increasing according to nitrogen level increased both transplanting and direct seeding on paddy surface. Leaf area index, canopy photosynthetic activity, however, were lower in direct seeding on paddy surface than transplanting in the same nitrogen level. Nitrogen content per unit leaf area was high in transplanting.

• The Korean Journal of Ceramics
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• v.3 no.3
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• pp.173-176
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• 1997

Direct metal ion beam deposition is considered to be a whole new thin film deposition technique. Unlike other conventional thin film deposition processes, the individual deposition particles carry its own ion beam energies which are directly coupled for the formation of this films. Due to the nature of ion beams, the energies can be controlled precisely and eventually can be tuned for optimizing the process. SKION's negative C- ion beam source is used to investigate the initial nucleation mechanism and growth. Strong C- ion beam energy dependence has been observed. Complete phase control of sp3 and sp3, control of the C/SiC/Si interface layer, control of crystalline and amorphous mode growth, and optimization of the physical properties for corresponding applications can be achieved.

• Korean Journal of Weed Science
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• v.12 no.3
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• pp.230-260
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• 1992

The paper was reviewed the research results on weed dynamics and effective control methods in direct-seeded rice crop. Direct seeding method resulted in drastic increment of weed growth compared to transplanting method and also changed in troublesome weed flora. Two to three fold more weeds were harvested at the direct seeded rice and weed flora of dominant species shifted toward $C_4$type grass weeds. Some of the important troublesome weeds in direct seeded rice were Echinochloa crus-galle, Oryza saliva ssp spontanea, Leptochloa chinensis. Setaria viridus. Digitaria adsendens, Sesbania exaltata, Aeschynomene indica, Algae, etc. Yield loss due to weed competiton was about 40-60% for water-seeded and about 70-100% for dry-seeded rice while these for transplanted rice were about 25-35% for mechanical transplanting and about 10-20% for manual transplanting, respectively. Integrated weed management concept was neede to approach weed control effectively. Several cultural technologies were very effective to suppress the weed growth. These were tillage operation, water management, seeding date and seeding rate. Crop residues of barley, rice, wheat, oat and italian ryegrass were also effectivly suppressed the paddy weeds particularly to Potamogeton distiuctus, a perennial broadleaf weed. A pathogen of Epicoccosorus nematosporus identified from Eleocharis kuroguwai was an excellent potential bioagent to control the most troublesome perennial sedge weed of E. Kuroguwai without arising any detrimental effect. The herbicidal efficacy of this pathogen was as high as bentazon herbicide. Plant growth regulator of paclobutrazol (pp-333) was another possible alternative to reduce the herbicide use. In current, herbicide exhibited the most conspicuous results to control weeds in direct-seeded rice even though the application technologies were not fully established. Recommendations for herbicide application were suggested for in both water-and dry-seeded rice in USA, Japan and Korea, respectively. To make better and comprehensive recommendations further studies on weed ecology and herbicide development were emphasized.

• Journal of Bio-Environment Control
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• v.11 no.2
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• pp.88-92
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• 2002

The study was conducted to estimate stimulation of plant growth of blue and red leaf lettuce (Lactuca sativa L.) as affected by covering methods with vinyl materials containing concentrated PO film. Plants were grown in direct, direct and tunnel, and tunnel covering with 'Pasraido materials' from October 13 to 31. With the covering mean air temperature, soil temperature, leaf temperature and relative humidity remarkedly increased. Higher temperature was observed in the order of direct and tunnel, direct, tunnel covering and the control. Photosynthetic photon flux (PPF, $\mu$mol m$^{-2}$ . s$^{-1}$ ) was observed in reverse order of temperature. Concentration of $CO_2$ was higher during night than during day under the light. Accumulation of highest $CO_2$ at night was obtained from direct coverings followed by direct and tunnel, tunnel covering and the control. Plant height, leaf number and leaf area of blue and red lettuces were stimulated by direct covering. However, there was no significant difference.

• Korean Journal of Medicinal Crop Science
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• v.13 no.6
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• pp.241-244
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• 2005

This study was carried out to compare growth characteristics, and extract and crude saponin contents of 4-year-old ginseng cultured by direct seeding and transplanting cultivation at several farms of the main producing district, Geumsan and Eumsung. Though root weight per plant of direct seeding cultivation was lower than that of transplanting cultivation, but yield of the former was higher than that of the latter owing to high rate of survival plant and Leaf Area Index. Dry matter partitioning ratio of direct seeding cultivation was high in primary root and low in secondary root because direct seeding cultivation elongated the length of primary root, while it suppressed the growth of secondary root. Ratio of rusty root was decreased in condition of direct seeding cultivation, while the contents of extract and crude saponin were lower than that of transplanting cultivation.

• Journal of Korea Technology Innovation Society
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• v.6 no.3
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• pp.328-344
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• 2003

This paper is aimed at analyzing the effect of Information Technology (IT) investment on the output growth and Total Factor Productivity (TFP) of Korean stock industry. Data on 24 stock firms for the eleven years (1991-2001) are used for the analysis. It is identified that there are both direct and indirect impacts of IT investment of the Korean stock industry on output growth. The total effect on output growth is 1.34 percentage point per year, which divided into a direct effect of investment in IT on the output growth is 1.97 and an indirect effect on the TFP is -0.63 percentage points per year. Results show that IT investment cannot contribute to increased stock industry productivity. Therefore, the Korean stock industry has not benefited from increased investment on IT in increasing productivity, implying the so-called productivity paradox has existed during the period.