• Proceedings of the Korea Association of Crystal Growth Conference
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• 1998.06a
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• pp.101-104
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• 1998

• Korean Journal of Plant Tissue Culture
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• v.22 no.2
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• pp.89-93
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• 1995

Regeneration and growth of bulblets from bulblet-derived bulb-scale segment of Lilium longiflorum (cv Georgia) were investigated. Bulblets were initiated on bulb scales taken from bulblets on MS medium containing 0.05 mg/L 2,4D with 3% sucrose or 0.02 mg/L 2,4D with 9% sucrose. Benzyladenine promoted the differentiation of bulblets but inhibited the growth of differentiating bulblets. The growth of bulblet was promoted by supplying 1/2 strength 1/2 NH$_4$NO$_3$ concentration in MS medium containing 12% sucrose.

• Korean Journal of Microbiology
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• v.13 no.3
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• pp.101-108
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• 1975

Physiological effects of 2,4-D on the growth of Chlorella ellipsoidea were investigated culturing the alage in the MN4 media containing 0. $10^{-4}/M$ and $4<\times}10^{-4}M$ 2,4-D. During 6 days culture were taken to analysis with respect to overall growth, photosynthesis, respiration and chemical composition. Results obtained from the experiment were as follows : 1) The growth of chlorella was increased at $10^{-4}M$ and decreased at $4{\times}10^{-4}M$ of 2,4-D concentrations 2) At $10^{-4}M$ pf 2,4-D cpncentration, the activity of photosynthesis enhanced relative to contro. while at $4{\times}10^{-4}M$ it was not changed. In both concentrations, however, the rate of respiration was down from the control. 3) At $10^{-4}M$ 2,4-D, the concentration of carbondrate metabolites was not changed relative to control, while significant increase in the concentrations of proteins and nucleic acids was observed. On the other hand at $4{\times}10^{-4}M$ of 2,4-D concentrations, all the metabolites including carbohydrates, proteins and nucleic acids were descreased. 4) It is concluded that 2,4-D at $10^{-4}M$ concentration accelerates the growth of chlorella by promoting the activities of photosynthesis and biosynthesis of proteins and nucleic acids.

• Journal of Plant Biotechnology
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• v.47 no.4
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• pp.337-344
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• 2020

Plant growth-promoting microorganisms promote plant growth by supplying nutrients to roots and interacting with the intrinsic factors in plants through volatile organic compounds (VOCs). In this study, we evaluated the effect of UOS, plant growth-promoting fungi (PGPF) isolated from previous study, on the growth of Nicotiana tabacum L. var Xanthi nc. Phylogenetic analysis and GC-MS were used to identify the fungal species and the VOCs emitted by the UOS, respectively. The fresh weight of UOS-treated Nicotiana tabacum L. was 3.8 and 4.2-fold higher than that of the control groups grown in vertical and I-plates, respectively. Moreover, in the UOS-treated plants, the length of the primary root was half and the number of lateral roots were twice compared to those in control plants. The UOS was identified as Phoma sp. by studying spore and mycelial morphology and using phylogenetic analysis. GC-MS revealed that the VOC emitted by the UOS was hexamethylcyclotrisiloxane (D3). These results suggest that the UOS of Phoma sp. influences plant growth and root development through D3. We expect this UOS and its VOC, D3 to be utilized in the future to increase growth and enhance yield for other plants.

• Journal of Animal Science and Technology
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• v.64 no.2
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• pp.302-311
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• 2022

This study investigated the effect of a synergistic blend of free and buffered organic acid (FMP) on the performance of piglets born to sows supplemented with a blend of short- and medium-chain organic acids (SGG) during the late gestation and lactation period. A total of 150 multiparous sows (n = 50/treatment, Landrace × Yorkshire) were blocked (2.4 parity) and assigned to 1 of 3 dietary treatments: CON - corn-soybean meal-based basal diet, SGG-Low - CON+ 1.5 kg/ton SGG, and SGG-High - CON + 3kg/ton SGG. During weaning, 600 piglets (6.72 ± 0.5kg) which weaned from sows supplemented with 3 levels of SGG were allocated to 2 weaner diets (Control and FMP - 3kg/ton) following 3 × 2 factorial arrangement. Supplemental effects on performance were measured at d0-d21 and d 21-42, and the entire period. Pigs fed with FMP and born to sows supplemented with SGG-High gained more weight and ate more (p < 0.05) compared with those in the CON group in both phases, and with SGG-Low in the second phase. Over the entire post-weaning period, piglets born to sows supplemented with SGG-Low and SGG-High had a higher average daily gain (ADG) and body weight (BW) (p < 0.05). Regardless of sow treatment, pigs fed with an FMP diet had higher ADG (p < 0.001), BW (p = 0.045), and a lower feed conversion ratio (p = 0.033). Also, feeding FMP diets reduced the fecal Escherichia coli and Clostridium perfringens counts at d42. The current study indicates that sows fed SGG supplement had a positive carry-over effect on the post-weaning growth rate, and FMP supplement enhances the growth performance and reduced the number of C. perfringens and E. coli. Thus, the application of 3 kg/ton of SGG in sows' diet and subsequent feeding of piglets with FMP would be an effective strategy to improve growth rate and reduce pathogenic bacteria in post-weaned piglets.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.11
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• pp.1005-1009
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• 2006

High quality three-dimensional (3D) heterostructures were constructed by selective area (SA) molecular beam epitaxy (MBE) using a specially patterned GaAs (001) substrate to improve the efficiency of tarrier transport. MBE growth parameters such as substrate temperature, V/III ratio, growth ratio, group V sources (As2, As4) were varied to calibrate the selective area growth conditions and the 3D GaAs-AlGaAs heterostructures were fabricated into the ridge type and the V-groove type. Scanning micro-photoluminescence $({\mu}-PL)$ measurements and the following analysis revealed that the gradually (adiabatically) coupled 1D-2DEG (electron gas) field effect transistor (FET) system was successfully realized. These 3D-heterostructures are expected to be useful for the realization of high-performance mesoscopic electronic devices and circuits since it makes it possible to form direct ohmic contact onto the (quasi) 1D electron channel.

• Journal of Korean Society of Forest Science
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• v.61 no.1
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• pp.37-44
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• 1983

This study was to estimate total annual volume growth by the measurement of mean tree growth during the last 10 years. Surveyed Forest stand was the second block (20.80 ha.)of Kyung Hee University Forests located at San 58 and 64, Gaegok-Ri, Gapyung-Yeup, Gapyung-Goon, Kyunggi province in Korea. The stand was mainly composed of uneven-aged Pinus densiflora and the estimation of tree volume was conducted by taking the cores at the D.B.H. of the sample tree which was selected by sub-sampling. The results obtained were as follows; 1) The regression between the diameter (D) and diameter growth ($\hat{I}$) was $\hat{I}=0.5499+0.0101D$. 2) The estimated equation of confidence interval for the diameter growth was $S^2{\hat{I}}=0.00817(0.09538-0.00952D+0.00027D^2$) 3) The equation for estimating tree height (H) from diameter was $H=1.32376D^{0.77958}$ 4) The equation for estimating tree volume from diameter and height $V=0.0000622D^{1.6918}H^{1.1397}$ 5) Total annual tree volume growth was $5.4041m^3/ha$, and ranged from 5.6131 to $5.1984m^3/ha$. 6) Annual growth rate of total tree volume and its error were 8.8% and 3.9%, respectively. The annual volume growth per tree for any districts can be estimated by this method, and the annual volume growth will be successfully predicted. Because of poor forest growing stock in Korea, annual amount of allowable cut should not exceed annual tree volume growth for better forest management. Accordingly, annual amount of allowable cut should be either equal to or less than annual tree volume growth for the balanced establishment between timber supply and demand in Korea. Demand shortage will be substituted with imported timber. Such plans enable Korean Government to develop a better policy of forest resources management.

• Progress in Superconductivity and Cryogenics
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• v.19 no.2
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• pp.14-18
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• 2017

This study presents three dimensional (3-D) seeding technique which is a modification of interior seeding. 3-D seeding is beneficial for shortening the processing period and enhancing the magnetic properties of REBCO bulk superconductors fabricated by melt growth. Oxygen channels were provided by using divided powder compacts instead of by using a rubber insert. Microstructure observations revealed that the grains grown from the seeds impinged each other and formed low angle grain boundaries of (001)/(001). It has been shown that the 3-D seeding technique reduces the volume fraction of a-c growth sector and thereby maximizes the area of a-b growth sector which attribute to the high magnetic characteristics of single grain REBCO bulk superconductors.

• Journal of Technology Innovation
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• v.11 no.1
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• pp.79-97
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• 2003

R&D expenditure of Korean firms has been increasing drastically since 1980 and occupied 84% of total R&D expenditure in 1994. After 1994, however, the growth rate of industry R&D expenditure has dropped below single digit. R&D concentration rate of upper 20 companies declined from 61.9% in 1999 to 49.8% in 2001. The technology trade balance has diverged by 2.8 billion dollars in 2000 compared to around 0.3 billion dollars in 1985. We find several reasons on declining the industry R&D growth rate in Korea. First, we carefully say there might be an crowding out effect in increasing government R&D investment from Granger causality test between industry R&D and government R&D. Second, the decreasing benefit of tax credit since 1992 on industry R&D expenditure has caused the decrease of industry R&D growth rate. Third, the type of R&D cost becomes to similar to matured countries type of cost, which means the portion of capital expenditure has been decreased since late of 1980s. Therefore, industry R&D growth rate gets to saturation point. We draw several policy implications from the changing structure of business R&D of Korean company. Firstly, to stimulate industry R&D investment Korean government needs to strengthen tax credit policy. Secondly, to induce foreign direct investment Korean government needs to establish technology infrastructures and high quality of manpower. To utilize foreign technology resources Korean government need to introduce global R&D program executed by foreign scientist as an Project Leader.

• Korean Journal of Community Nutrition
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• v.20 no.3
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• pp.197-207
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• 2015

Objectives: This study was conducted to investigate the effects of the sources of vitamin D (duration of exposure to sunlight, intake of major food sources for vitamin D or vitamin D supplements) on the serum 25-(OH) $D_3$ levels, and the physical growth of a child. Methods: Subjects were 296 children aged 1 to 5 years who visited S hospital located in Changwon City. Survey data collection was carried out by direct interview method, and the biochemical data were collected using hospital records. Results: The study subjects were divided into three groups according to their levels of serum 25-(OH) $D_3$ (deficient, relatively insufficient, sufficient) and their percentage were 48.3%, 44.3% and 7.4% respectively. The average concentration of serum 25-(OH) $D_3$ was $20.41{\pm}6.55ng/mL$, which was relatively insufficient. The average duration of exposure to sunlight was $58.86{\pm}49.18minutes/day$. A total score of vitamin D major food sources was 46.71 points (full marks 153), and the most frequently consumed food items were milk, eggs, and cheese. Thirty-four percent of the subjects took vitamin D supplements and their dose were $11.96{\mu}g/day$. Three vitamin D sources in sufficient group were higher than deficient or relatively insufficient group significantly. Intake of vitamin D supplements showed positive relation (+) and high explanation power ($R^2=0.288$) on serum 25-(OH) $D_3$ concentration, but intake of vitamin D major food sources (+) and the duration of exposure to sunlight (+) had a low explanation power ($R^2=0.068$). The relations between serum 25-(OH) $D_3$ concentration and physical growth (height and weight) were shown as negative (-), and their explanation powers were low as 7.3% and 5.9% respectively. Conclusions: This study results can be useful when discussing the intake standard of vitamin D and the effective intake method for children. In addition, it will be helpful to build the children's nutrition policy and to plan the nutrition education program to improve the vitamin D status in children.