• Title/Summary/Keyword: Order of growth

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Sex Differences in Physical Growth Model (신체 성장곡선 및 성별 차이에 관한 연구)

  • 정병용
    • Journal of the Korean Society of Safety
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    • v.8 no.4
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    • pp.183-188
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    • 1993
  • Anthropometric characteristics and considerations of sex differences are essential for the correct design of ergonomic work spaces. This paper is concerned with longitudinal study on the physical growth in Korean youth. Three hundred eighty-seven subjects were selected from third year students of high schools, and their records on physical examination during the last twelve years were surveyed by longitudinal method. For boys and girls, this study investigated the anthropometric characteristics of physical structure and the shape of physical growth. The result showed that the physical growth spurt of girl occurred earlier than that of boy. Also, by regression analysis, the third-order polynomial function was suitable for the growth curves of stature and weight, and there were significant sex differences in the fitted curves.

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Fatigue Crack Retardation and Retardation Mechanism in Variable Loading (The Effects of Crack Tip Branching in Crack Growth Retardation)

  • Song, Sam-Hong;Kwon, Yun-Ki
    • International Journal of Precision Engineering and Manufacturing
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    • v.3 no.3
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    • pp.76-81
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    • 2002
  • In order to study the fatigue crack and retardation mechanism in variable loading, the effects of crack tip branching in crack growth retardation were examined. The characteristics of crack tip branching behavior were considered with respect to microstructure and crack tip branching angle was examined. Crack tip branching was observed along the grain boundary of finite and pearlite structure. It was found that the branching angle ranges from 25 to 53 degrees. Using the finite element method, the variable of crack driving farce to branching angle was examined. The effective crack driving farce (K$\_$eff/) decreased as the branching angle increased. The rate of decrease was 33% for kinked type and 29% for forked one. It was confirmed that the effect of crack tip branching is a very important factor in crack growth retardation. Therefore, crack branching effect should be considered in building the hypothetical model to predict crack growth retardation.

Impact of Foreign Direct Investment and International Trade on Economic Growth: Empirical Study in Vietnam

  • NGUYEN, Hieu Huu
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.3
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    • pp.323-331
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    • 2020
  • The study aims to assess the impact of foreign direct investment (FDI) and international trade (export and import) on Vietnam's economic growth for the 2000-2018 period. Secondary data is taken from the General Statistics Office of Vietnam. Ordinary least-square method is used in analyzing the impact of FDI, export and import on economic growth of Vietnam. Empirical test results show that FDI and international trade are related to Vietnam's economic growth. However, each economic variable has a different impact. FDI has a positive and statistically significant influence on economic growth of Vietnam. Export also has positive and statistically significant impact to the economic growth, while import has a negative but not statistically significant effect. The result is useful for the policy makers of Vietnam on foreign economic relations. In order to improve the effect of FDI and international trade on growth of the economy, the government of Vietnam should: (1) continue applying preferential policies to attract FDI; (2) select foreign investors aiming to quality, efficiency, high technology and environmental protection; (3) continue pursuing export-oriented policy; (4) enhance the added value of exported goods and control the type of imported goods; (5) further liberalize trade through signing and implementation of international trade commitments.

Growth Inhibition of Garlic (Allium sativum L.) Juice on the Microorganisms (마늘즙의 미생물증식 억제효과)

  • Ji, Won-Dae;Jeong, Min-Seon;Choi, Ung-Kyu;Choi, Dong-Hwan;Chung, Yung-Gun
    • Applied Biological Chemistry
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    • v.41 no.1
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    • pp.1-5
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    • 1998
  • In order to investigate antimicrobial substances from natural spices, the effects of garlic juice and ginger juice on the growth of microorganisms were investigated. It was showned that garlic juice inhibited the growth of bacteria, yeasts and fungi but ginger juice did not inhibit the growth of bacteria and yeasts. As result of concentration effect of garlic juice on the growth of microorganisms, the higher concentration of garlic juice was employed, the more growth inhibition was obtained. Comparing the specific growth rate at various concentration of garlic juice, the inhibition effect on yeast appeared much higher than that on bacteria.

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Growth characteristics of 4H-SiC homoepitaxial layers grown by thermal CVD

  • Jang, Seong-Joo;Jeong, Moon-Taeg;Seol, Woon-Hag;Park, Ju-Hoon
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.9 no.3
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    • pp.303-308
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    • 1999
  • As a semiconductor material for electronic devices operated under extreme environmental conditions, silicon carbides(SiCs) have been intensively studied because of their excellent electrical, thermal and other physical properties. The growth characteristics of single-crystalline 4H-SiC homoepitaxial layers grown by a thermal chemical vapor deposition (CVD) were investigated. Especially, the successful growth condition of 4H-SiC homoepitaxial layers using a SiC-uncoated atmospheric pressure chamber and carried out using off-oriented substrates prepared by a modified Lely method. In order to investigate the crystallinity of grown epilayers, Nomarski optical microscopy, Raman spectroscopy, photoluninescence(PL), scanning electron microscopy(SEM) and other techniques were utilized. The best quality of 4H-SiC homoepitaxial layers was observed in conditions of growth temperature $1500^{\circ}C$ and C/Si flow ratio 2.0 of $C_{3}H_{8}\;0.2\;sccm\;&\;SiH_{4}\;0.3\;sccm$. The growth rate of epilayers was about $1.0\mu\textrm{m}/h$ in the above growth condition.

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The growth and characterization of Rb-doped $KNbO_3$ nonlinear optical crystals

  • Beh, C.Y.;Chong, T.C.;Kumagai, H.;Hirano, M.
    • Proceedings of the Korea Association of Crystal Growth Conference
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    • 1997.06a
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    • pp.149-155
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    • 1997
  • We have successfully grown colorless and transparent Rb-doped potassium niobate (KRN) single crystals using the top seeded solution growth(TSSG) technique. In our crystal growth experiments, the Rb doping concentrations within the melt range from 2-15 mol% relative to that of Nb$_2$O5. Atomic absorption measurements indicate that the Rb content in the KRN solid solution is rather low; the Rb segregation coefficient is found to be on the order of 0.05. It is believed that this is due to the relatively much larger Rb+ ionic radius compared to that of K+, rendering it more difficult for Rb to replace K in the KNbO$_3$(KN) host lattice. Preliminary single-pass second harmonic generation (SHG) experimental results indicate that there exists marginal improvement in the phase-matching temperature tolerance of KRN compared to that of pure Kn single crystals.

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Biocontrol Effect of Gliocladium virens G1 and Soil Amendment on Astragal Stem Rot Caused by Rhizoctonia solani

  • Chung, Bong-Koo;Yun, Kyung-Ho
    • Mycobiology
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    • v.28 no.4
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    • pp.180-184
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    • 2000
  • In order to find an environment-friendly method to suppress astragal stem rot caused by the isolates of Rhizoctonia solani AG 1 and AG 4, we tested an antagonistic fungus Gliocladium virens G1 was evaluated as a biocontrol agent and estimated inorganic compounds and organic materials were tested for their effect of the disease suppression. G. virens G1 effectively inhibited mycelial growth in a dual culture and caused mycelial lysis in the culture filtrate. No adverse effect was observed when examined for seed germination and seedling growth. Promoted seedling growth was observed with the seed treatment. Seeds of astragal plant were germinated higher in the sterile soil than the natural soil. Of 14 inorganics tested, alum, aluminum sulfate and calcium oxide significantly suppressed the mycelial growth and sclerotial germination. Milled pine bark and oak sawdust also suppressed the mycelial growth. Soil amended with 1% of G. virens G1 composted with pine bark (w/v) significantly controlled astragal stem rot in the glasshouse experiments.

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Effect of Debinding Conditions on the Microstructure of Sintered Pb(Mg1/3Nb2/3)O3-PbTiO3

  • Yun Jung-Yeul;Jeon Jae-Ho;L.Kang Suk-Joong
    • Journal of Powder Materials
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    • v.12 no.4 s.51
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    • pp.261-265
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    • 2005
  • In order to fabricate complex-shaped polycrystalline ceramics by sintering, organic binders are usually pre-mixed with ceramic powders to enhance the formability during the shape forming process. These organic binders, however, must be eliminated before sintering so as to eliminate the possibilities of poor densification and unusual grain growth during sintering. The present work studies the effect of binder addition on grain growth behavior during sintering of $92(70Pb(Mg_{1/3}Nb_{2/3})O_3-30PbTiO_3))$-8PbO(mol%) piezoelectric ceramics. The microstructures of the sintered samples were examined for various heating profiles and debinding schedules of the binder removal process. Addition of Polyvinyl butyral(PVB) binder promoted abnormal grain growth especially in incompletely debinded regions. Residual carbon appears to change the grain shape from comer-rounded to faceted and enhance abnormal grain growth.

Growth-Suppressing Activity of the Transfected Cx26 on BICR-M1Rk Breast Cancer Cell Line

  • Lee, Hae-Jung;Rhee, Seung-Keun
    • Journal of Microbiology and Biotechnology
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    • v.21 no.5
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    • pp.477-482
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    • 2011
  • There are accumulating evidences suggesting that connexin (Cx), a gap junction channel-forming protein, acts as a growth suppressor in various cancer cells, and this effect is attributeed to the gap junction-mediated intercellular communication (GJIC). In order to characterize the relationship between the growth-arresting activity of Cx26 and its cytoplasmic localizations after expression, we linked a nuclear export signal (NES) sequence to Cx26 cDNA before transfecting into a rat breast cancer cell line. A confocal fluorescent microscopic observation revealed that the insertion of NES minimized the nuclear expression of Cx26, and increased its cytoplasmic expression, including plasma membrane junctions. Total cell counting and BrdUrd-labeling experiments showed that the growth of the breast cancer cells was inhibited by 74% upon transfection of Cx26-NES, whereas only 9% inhibition was observed with only Cx26 cDNA.