• Title/Summary/Keyword: rapid growth

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Phase Formation Characteristics of Superconducting $YBa_2Cu_3O_{7-x}$ Prepared by the Melt-Textured Growth (용융-조직 성장에 의한 초전도성 $YBa_2Cu_3O_{7-x}$상의 생성 특성)

  • 장현명;문길원
    • Journal of the Korean Ceramic Society
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    • v.27 no.5
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    • pp.677-683
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    • 1990
  • Melt-textured growth of the YBa2Cu3O7-x phase from a supercooled melt created locally aligned, barshaped grains of the orthorhombic 1-2-3 phase. Based on all the observed phenomena, the gross mechanism of the melt-textrued growth of YBa2Cu3O7-x on the (100) plane of MgO was delineated by three basic patterns of reactions. These are : (ⅰ) formation of the aligned 1-2-3 phase and the Y-rich 2-1-1 phase at the bulk region away from the (100) plane of MgO ; (ⅱ) formation of the Cu-richprecipitates at the interfacial region by the selective interface-induced precipitation of the liquid phase ; (ⅲ) condensation reaction of the entrapped Cu-rich vapor with Mg atoms during the initial stage of rapid cooling from 130$0^{\circ}C$ to 98$0^{\circ}C$.

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Structural Change as a Source of Growth: An Empirical Evidence from OECD Countries

  • Han, Hongyul
    • Analyses & Alternatives
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    • v.6 no.1
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    • pp.195-222
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    • 2022
  • From the economic development perspective, economic growth should accompany structural improvement in order to meet complex demands from a society. In the context of development economics, economic growth is critically dependent on successful structural advancement. The issue of structural change is also important for advanced economies as the landscape of modern industry is changing fast. Many advanced countries of slow growth are experiencing dawdling changes in industry structure. However, there is no definitive answer to the question of whether there is a causal relationship between structural change and growth. This study empirically assesses the relationship between structural change or 'speed' thereof and economic growth in developed countries of OECD. Rather than looking into the causes of structural changes, this study simply measures structural changes in OECD economies and examines if structural change is really contributing to growth. The reason why this study focuses on advanced countries of OECD is rather obvious; technological innovation and emergence of new industries pressure these countries to restructure their economies to address these new challenges though they are at stages well beyond conventional industrialization. And structural rigidity can always limit growth even in advanced countries. The main results of this study can be summarized as a positive relationship between 'change and growth'. 'Change' in this study refers to changes in the industrial structure based on value-added and was analyzed to have a close positive relationship with economic growth. This result is consistent with arguments of early development economists emphasizing structural upgrade as an indispensable process for growth and development. The result of this study potentially confirms that the main argument of development economics is valid also for advanced economies. One of our results suggests that business/professional services and social services should be main targets for restructuring for advanced economies. The rational may be that rapid convergence of manufacturing and services is a key for structural advancement in the era of new technologies. Obviously, as manufacturing technology and production are standardized, it is difficult to secure international competitiveness through traditional manufacturing alone and the role of R&D, design, logistics, and marketing is becoming more important.

Effect of Electrolyzed Acidic Water on the Growth of Soybean Sprout. (산성 전해수가 콩나물의 생육에 미치는 영향)

  • 윤동준;이정동;강동진;박순기;황영현
    • Journal of Life Science
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    • v.14 no.5
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    • pp.809-814
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    • 2004
  • To investigate the effect of the electrolyzed acidic water for soybean sprouts growth, the responses of characteristics of soybean sprouts were evaluated. Soybean sprouts grown by the electrolyzed acidic water showed shorter length in total body, root, and hypocotyl, etc. but they were evaluated to be increased in hypocotyl diameter and weight per sprout. Total length of soybean sprouts grown for 5 days by electrolyzed acidic water were much shorter than those by tap water. Soybean sprouts grown by tap water showed rapid growth in length even after 5 days but no more growth in length for those grown by electrolyzed acidic water. The growth of hypocotyl showed the same tendency as total length. No difference in root length among the soybean sprouts grown for 4 ~ 11 days by electrolyzed acidic water while those grown by tap water showed continuous rapid growth in length. The diameter of hypocotyl was thicker in those grown by electrolyzed acidic water than those grown by tap water and increased up 5 days. The weight of cotyledon grown by electrolyzed acidic water showed the proportional increase to the growing days but those grown by tap water showed no increase in hypocotyl weight up to 7 days, but a little bit increase after 11 days with the growth of new buds. The fresh weight per sprout was higher in those grown by electrolyzed acidic water until 7 days than tap water but it was the same weight in 11 days cultivation. The electrolyzed acidic water effected on shortening of hypocotyl and root length, thickening of hypocotyl diameter, and enlarging of cotyledon during soybean sprout cultivation.

Cross-sectional Cell Anatomy and Physiological Growth Responses of Cells in Root Growth Zones of Two Tall Fescue Genotypes at Two Nitrogen Levels (톨페스큐 뿌리생장부위의 횡적 해부구조 및 세포생장의 생리적 반응에 대한 질소효과)

  • Beom Heon, Song;Curtis J, Nelson
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.40 no.3
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    • pp.297-307
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    • 1995
  • Anatomical and physiological studies of sink tissues are required for better understanding the biological plant growth system and energy metabolism Anatomy of root growth zones of two genotypes of tall fescue (Festuca arundinacea Schreb.) receiving 50 or 200 ppm N were determined, Cross-sectional anatomy and cells responses of root growth zones were observed and examined. Rapid radial root expansion occurred within the first 1.0 mm from root apex, and then increased gradually for both genotypes and N levels. Another increase in diameter occurred at high N after cell elongation slowed near 3.0 mm. Area of the central cylinder cell increased rapidly near the root apex. However, it then decreased again about 1.0 to 1.5 mm from the apex, perhaps because of pressure from the rapid increase of root diameter due largely to an increasing proportion of cortex and epidermis or hypodermis in the distal portion of the root growth zone. Root area from the apical initial to 6.0 mm distal consisted of 10 to 18% epidermis or exodermis, 67 to 79% cortex, and 10 to 22% vascular cylinder cells containing cambium cells (6 to 20%) and xylem cells (0.8 to 2.5%). These data indicate that N application affects root growth radially by increasing mainly cortex cell area, with less effect on epidermis and central cylinder cells.

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Examination of the Restructuring of Korean Economy: Simulation of the Multisector Model (한국경제(韓國經濟)의 구조변화(構造變化) 전망(展望): 다부문모형(多部門模型)의 모의실험(模擬實驗))

  • Kim, Jung-ho;Park, Jun-kyung
    • KDI Journal of Economic Policy
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    • v.14 no.2
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    • pp.155-187
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    • 1992
  • The Korean economy has sustained high growth rate for almost three decades, that have been associated with the rapid expansion of manufacturing industries. In the beginning stage of development, the high growth of the Korean economy has been based on improvements in productivity obtained by the economies of scale. In that period, the improvements in productivity could be secured by the economies of scale in the export-oriented industries which are the labor- and material-intensive industries. In the latter half of the 1980s, the Korean economy went through rapid transition. Now Korea is at another juncture in its development process, where economic restructuring is critical to sustain high growth. However, economic restructuring in the 1990s call for much more concerted effort than before, since changes in internal and external conditions have profoundly altered the environment for economic development. If Korea is to sustain high growth in the 1990s, it has to promote balanced economic and social development in coordination with the smooth facilitation of industrial restructuring. There are no inherent conflicts among the issues involved, so they can be resolved by restructuring the economy to facilitate, in a global context, the development of knowledge- and technology-intensive activities and to ensure that the benefts of growth are reflected of qualitative improvements in national living standards. In this paper, we examined a scenario of structural changes using a mid- and long-term multisector model, in order to understand the conditions needed for realizing the growth potential. This examination explains the important features of the development course and policy directions that will help sustain high growth in the 1990s.

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The Importance of Artificial Intelligence to Economic Growth

  • HE, Yugang
    • Korean Journal of Artificial Intelligence
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    • v.7 no.1
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    • pp.17-22
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    • 2019
  • The rapid development of artificial intelligence technology has exerted a great influence on all fields of the world, which of course also affects the world economy. This has also aroused a large number of economists' interest in this proposition. Since the definition of artificial intelligence is not unified yet, the results from previous researches are not reliable enough. At present, most scholars use the neoclassical growth model or task-based model to explore the path of artificial intelligence on economic variables. There into, most of them use the degree of automation to represent the artificial intelligence. They find that the degree of automation can change the proportion of industries. This only verifies that artificial intelligence can affect the economic variables. But the magnitude of artificial intelligence on economic variables can not be correctly estimated. Therefore, in order to have a better understanding on the impact of artificial intelligence on economic growth, this paper systematically reviews and collates previous literature on this topic. The results of this paper indicate that both in theoretical and empirical studies, artificial intelligence has a positive effect on economic growth. Then, some suggestions and limitations have also been put forward accordingly.

Mineralogical Characteristics and Formation Processes of Zonal Textures in Hydrothermal Epidote from the Bobae Sericite Deposit (보배 견문모 광상에서 산출하는 녹염석의 누대구조의 특징과 발달과정)

  • 추창오
    • Economic and Environmental Geology
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    • v.34 no.5
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    • pp.437-446
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    • 2001
  • Zoned epidotes formed by the propylitic alteration of the Bobae sericite deposit in western Pusan show complex compositional zoning patterns, such as multiple growth zoning, oscillatory zoning, patchy zoning and irregular zoning. The complex zoned epidote, in general, shows AI-rich cores and Fe-rich rims. Pistacite component (Ps) in the epidote ranges from 18.5 to 74.3 mot.%. Remnant textures in multiple growth zoning indicate that the earlier zone was partially resorbed prior to growth of later one. Multiple growth zoning and oscillatory zoning suggest that hydrothermal system underwent rapid changes and fluctuations in fluid chemistry, redox condition, or temperature.

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Nutritional Studies on the Growth of the Rapamycin-Producing Streptomyces hygroscopicus

  • Kim, Wan-Seop;Davis, Sean;Wong, Grace;Demain, Arnold-L.
    • Journal of Microbiology and Biotechnology
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    • v.13 no.4
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    • pp.560-563
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    • 2003
  • During our previous studies on the relationship between nutrient requirements of S. hygroscopicus C9 and rapamycin biosynthesis, we developed chemically-defined media containing among other nutrients, aspartic acid, arginine, histidine, or ammonium sulfate. However, these media (“Cheng et al. medium” and “Lee et al. medium”) showed very slow growth characterized by a very long lag phase of growth. In an attempt to develop a chemically-defined or semi-defined medium to support more rapid growth and increased cell production, we have carried out studies to shorten the lag phase. Of the various additives tested, vitamin-free casein acid hydrolysate was the most significant by shortening the lag phase by 2-3 days. Mixtures of amino acids failed to replace casein acid hydrolysate. The active principle passed through an ultrafilter with a molecular weight cutoff of 1,000 and thus may be a peptide. The present work has yielded a semi-defined medium which should be useful for further growth studies on S. hygroscopicus C9.

Rapid Micropropagation of Hovenia dulcis Thunb. Through in vitro Stem Nodal Cultures

  • Park, Dong-Jin;Kang, Young-Min;Jung, Ha-Na;Min, Ji-Yun;Kim, Yong-Duck;Karigar, Chandrakant S.;Choi, Myung-Suk
    • Journal of Korean Society of Forest Science
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    • v.95 no.2
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    • pp.155-159
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    • 2006
  • An efficient method for in vitro propagation of the medicinal plant Hovenia duleis, was established. Plantlets for micropropagation of H. dulcis were obtained from in vitro germinated seeds. The effectiveness of various levels of cytokinins (BAP, Kinetin and TDZ) on multiple shoot formation from stem nodes was tested. BAP (1.0 mg/L) treatment induced highest number of multiple shoots. The growth pattern of plantlet on various culture media was undertaken. The shoot elongation was optimal on 2MS basal medium without growth regulators. The in vitro rooting ability of H. dulcis shoots was examined with two-auxins IAA and IBA. The IAA (1.0 mg/L) treatments induced earliest rooting with maximum number of roots and root growth. Rooted shoots were transferred directly to small pots with artificial soil and such established plant exhibited a normal growth pattern similar to wild plantlet.

Nutrient Uptake and Growth Kinetics of Chattonella antiqua (Hada) Ono (Raphidophyceae) Isolated from Korea

  • Seo, Kyung-Suk;Lee, Chang-Kyu
    • ALGAE
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    • v.22 no.3
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    • pp.235-240
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    • 2007
  • The red tide-causing flagellate Chattonella anticfua can cause mass fish kills by their clogging in fish gills. Thisstudy examined the nutrient requirements of C. antiqua isolated from Korea. C. anticfua displayed maximum growthat the day five, followed by a decrease in cell density. Nitrate and nitrite were the preferred nitrogen sources, alonewith adenosine diphosphate for phosphorus compounds. In medium that contained ammonium, a significantdecrease in cell density was observed. Half-saturation constants, Ks, calculated from the maximum growth ratewere 4.94 U|M for NC>3 and 0.79 flM for P04. The growth of C. antiqua was not within the function of the N:P ratio (RU= 0.29). With an N:P ratio as low as 10, the increase in cell density was apparent, with a higher division rate. At lev-els above 50 fiM of NaNOg or 8 ;uM of NaHUPCU, the growth rates were somewhat decreased. Phosphate was thelimiting factor for C. antiqua growth since the starvation of phosphate had brought about a rapid decrease in celldensity in semi-continuous culture. Studies about the temporal modification of the efficiency of nitrate or phosphateuptake may be necessary to explain the bloom dynamics of C. antiaua.