• Journal of the Korean Society of Tobacco Science
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• v.19 no.1
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• pp.18-23
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• 1997

The study was carried out to clarify reasonable production of healthy seedling, optimal Pot depth, and appropriate transplanting time, which can be deduced from understanding of seedling quality. Seedling quality results from growth of root and shoot, morphology and distribution of root system under influence of Pot depth during seedling growing period. Stem height, shoot dry weight, leaf area and leaf number were increased in proportion to depth of pots. Growth of shoot and root during seedling growing period showed the most dramatic development between 20th and 25th day after temporary planting. Root number increased as pot depth decrease and total root length and dry weight increased as pot depth increase. In 5cm pot, relative multiplication rate was higher and mean extension rate was lower than other depth of Pot. The limitation of pot volume in which rhizosphere was located enhance the development of roots of second and third order. At 20th days after temporary Planting root distribution was relatively uniform in length and development of adventitious root on stem base was poor as Pot depth decreased.

• International Journal of Automotive Technology
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• v.6 no.3
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• pp.229-234
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• 2005

The dynamic crack growth in ductile steel is investigated by means of the impact loaded 3 point bending (3PB) specimens. Results from experiments and numerical simulations are compared to each other. A modified 3PB specimen designed with the reduced width at its ends has been developed in order to avoid the initial compressive loading of the crack tip and also to avoid the uncertain boundary conditions at the impact heads. Numerical simulations of the experiments are made by using a finite element method (FEM) code, ABAQUS. The high speed photography is used to obtain the crack growth and the data of the crack tip opening displacement (CTOD). The direct measurements of the relative rotations of two specimen halves are made by using the Moire interference pattern.

• Journal of Powder Materials
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• v.6 no.1
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• pp.81-87
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• 1999

Based on the pore filling theory, the microstructure evolution during liquid-phase sintering has been analyzed in terms of interrelationship between average grain size and relative density. For constant liquid volume fraction, the microsturucture trajectories reduced to a single curve in a grain size(x)-density(y) map, regardless of grain growth constant. The slope of curves in the map was inversely proportional to average pore size, while it increased fapidly with liquid volume fraction. Increase in pore volume fraction retarded the densification considerably, but showed marginal effect on the slope. The activation energy of densification was predicted to be the same as that of grain growth as long as the liquid volume fraction is constant for any temperature range studied. The present analyses on microstricture evolution may demonstrate the usefulness of pore filling theory and provide a guideline for process optimization of liquid-phase sintering.

• Journal of Ginseng Research
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• v.12 no.1
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• pp.87-91
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• 1988

Photosynthesis rates of ginseng (Panax quinquefolium) leaves were measured in a controlled environment at $20^{\circ}C$ under the different monochromatic light such as white(W), red(R) and blue(B) to obtain basic information applicable to the colored shading material for the ginseng growth. Photosynthesis rate relative to white(W) light was generally higher in R and lower in B comparing to white(W) light. This difference was negligible at the close to the light-saturation point, whereas the difference among the monochromatic light was extended with decreasing the irradiant. It suggests that red is good in color of shading material for growth of American ginseng.

• The Transactions of the Korea Information Processing Society
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• v.7 no.3
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• pp.852-861
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• 2000

Software reliability growth models are used in testing stages of software development to model the error content and time intervals betwewn software failures. In this paper, using priors for the number of fault with the negative binomial distribution nd the error rate with gamma distribution, Bayesian inference and model selection method for Jelinski-Moranda and Goel-Okumoto and Schick-Wolverton models in software reliability. For model selection, we explored the sum of the relative error, Braun statistic and median variation. In Bayesian computation process, we could avoid the multiple integration by the use of Gibbs sampling, which is a kind of Markov Chain Monte Carolo method to compute the posterior distribution. Using simulated data, Bayesian inference and model selection is studied.

• Proceedings of the Korea Society of Environmental Biology Conference
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• 2003.11a
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• pp.121-124
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• 2003

The goals of this study is to elucidate life cycle and to detect genetic differences within a single species of Heterosigma akashiwo. To elucidate life cycle of H. akashiwo, have to study of benthic stage and vegetative cell. So we studied identification of H. akashiwo cyst. The relative contents of DNA in nuclei were determined in Heterosigma akashiwo. Different stages of the life history were obtained from culture and natural sediments, and examined by microfluorometry after staining with the DNA-specific fluorochrome 4'-6-dianudubi-2-phenylindole(DAPI). Large cells mainly in exponensial stage, while small cell, pre-encystment cells(\ulcorner\ulcorner), showed in the end of the late growth stage. Type of DNA content showed the different with growth stage. Usually the small cell has the high level of IOD.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.75.1-75.1
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• 2013

Atomic layer deposition (ALD) and molecular layer deposition (MLD) are based on sequential, self-limiting surface reactions that produce atomic layer controlled and conformal thin film growth. ALD can deposit inorganic films and MLD can deposit films containing organics. ALD and MLD can be used together to fabricate a wide range of hybrid organic-inorganic alloy films. The relative fraction of inorganic and organic constituents can be defined by controlling the ratio of the ALD and MLD reaction cycles used to grow the film. These hybrid films can be tuned to obtain desirable mechanical, electrical and optical properties. This talk will focus on the growth and properties of metal alkoxide films grown using metal precursors and various organic alcohols that are known as "metalcones". The talk will highlight the tunable mechanical properties of alucone alloys grown using Al2O3 ALD and alucone MLD and the tunable electrical conductivity of zincone alloys grown using ZnO ALD and zincone MLD with DEZ and hydroquinone as the reactants.

• KDI Journal of Economic Policy
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• v.41 no.3
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• pp.77-96
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• 2019

This paper examines the relation between the skill premium and international trade given differences in the relative supply of skills across countries while allowing the South (developing countries) to develop its appropriate technology. Typical assumptions put forward in the literature state that either technology is exogenously given, or technical change is allowed only in the North (developed countries). I present a model of international trade with endogenous growth by allowing the South to direct its technology. The results show that more R&D is directed towards skill-augmenting technology in the North than in the South, in sectors with the same skill-intensity. Technical change induced by lowering trade costs can increase the skill premium in both the North and the South. This result can explain the empirical observation that the skill premium has increased within many developing countries after they experienced trade liberalization. Finally, the model predicts larger gains from trade compared with the model where technical change is either not allowed, or allowed only in the North.

• Korean Journal of Plant Resources
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• v.11 no.3
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• pp.326-334
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• 1998

Vascular cambium in 16 species of Salicaceae is nonstoried in all of them and is made up of fusiform and ray initials. The growth of cambial girth occurred by pseudotransverse division of fusiform initials and subsequent apical intrusive growth of daughter initials. The measurements of fusiform initials in tangerntial sections have revealed that the average length varies from 252.2-437.1${\mu}{\textrm}{m}$ in investigated species, with the maximum being in Populus euramericana and the minimum in Salix purprea var. Multinervis. The length of fusiform initials depends on the length of the tapering end wall , therefore, the longer the length of the tapering end wall, therefore, the longer the length of the taperding end wall, the longer the length of fusiform initials. Ray initials have their own size, magnitude, and frequency of occrrence in each species. The relative proportion of ray initials fall about 15.0-24.5% in Salicaceae. Shrubby species of Salix have a lower ratio of ray initials than the species which possess wider trunks. New ray initials are originated from cut off the side or the end of fusiform initials and central partition of a fusiform initials.

• Journal of Korean Society of Forest Science
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• v.85 no.3
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• pp.539-551
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• 1996

In this study, a number of distance-dependent competition indices on tree-level which incorporate the tree sizes and distances to competitors, and traditional stand-level density measures were estimated from the data compiled with position-dependent survey in a Pinus densiflora stand. The performance of the estimated competition indices was examined by comparing the relationship with the diameter growth, and a dbh growth function, in which the competition index is considered as a one of influence factors, are developed. In the searching method of competing trees, the competition index estimated with $30^{\circ}$ competition interrupting angle showed the highest correlation with the annual dbh growth, while the expanding the competing zone distance had no significant effect on the performance of competition index in estimating annual dbh growth. The most of the examined stand-level competition indices, based on distance-dependent single-tree competition indices, were evaluated to describe similarly the stand competition status. As a result of partial correlation analysis in which the effect of age and site index are eliminated, Alemdag's mean competition index and relative spacing index were determined to have the highest correlation with dbh. The relative spacing index, which can be easily measured in field without measuring the position of individual trees, was considered to be a better suited one for estimating mean dbh of a stand. Among distance-dependent competition indices on tree-level, Hegyi's competition index showed the best performance in their correlation with annual dbh growth, if eliminated the effect of site index and dbh. This enabled to derive the following annual dbh growth function of individual trees which incorporate age, dominant height, dbh and Hegyi's competition index as influence factors : $$dbh^{\prime}=3.975362676{\cdot}age^{-1.099274613}{\cdot}ho^{0.199893990}{\cdot}dbh^{0.269430865}{\cdot}HgCI^{-0.353643587}$$ This function is coincided to the growth principle in which site index has a positive effect on the annual dbh growth, while high age or competition causes to reduce the annual dbh growth, and can be used as a function in single tree growth model.