• Ecology and Resilient Infrastructure
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• v.7 no.4
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• pp.308-319
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• 2020

In this study, the field applicability of the recently constructed multifunctional fishway in Seomunbo, Yeongcheon-si, and Gyeongsangbuk-do were examined. The analysis variables were R/C slab (S1) and R/C+S/C slab (S2), the underground passage standard areas (width × length) were 1.4 m × 0.2 m, 1.4 m × 0.3 m, and 1.4 m × 0.6 m, and the flow velocities were 0.8, 1.2, and 1.6 m/s. As a result of the analysis, the safety of the design of Seomunbo was evaluated. The analysis showed compared to the Seomoon Weir fishway, the maximum stress of S2 decreased by 24 - 32%, the bending moment of the underground passage decreased by 16 - 33%, the maximum stress of the sidewall decreased by 20 - 36%. In addition, the bending moment of the upper slab decreased by 17 - 33%, the maximum stress of the upper slab decreased by 9 - 28%, and the bending moment decreased by 19 - 33%. Complementation was required in the following percentages: 18% and 14% for the maximum stress and bending moment of the underground passage, respectively, 15% and 17% for the maximum sidewall stress and bending moment, respectively, and 11% and 16% for the upper slab maximum stress and bending moment, respectively. The results showed that S2 was superior to that of the Seomoon Weir fishway, and the underground passage size of 1.4 m × 0.3 m was superior to those of 1.4 m × 0.2 m and 1.4 m × 0.6 m, and R/C+S/C slab was superior to that of R/C slab. The findings are expected to be useful for constructing and designing the multifunctional fishway.

• Journal of Bio-Environment Control
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• v.23 no.2
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• pp.144-147
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• 2014

It was intended to closely examine an effect that a change in the concentration of culture medium had on the potato(Solanum tuberosum L.) plantlet growth in the microponic system so as to mass-produce the virus-free plant of new variety 'Saebong' for potato processing. The adjusted concentration of potato culture medium was 0.2, 0.6, 1.0, 1.4, 1.8, and $14.0dS{\cdot}m^{-1}$. And potato seedling was cut into pieces of 1.5 cm in length, which included 2 growth points and leaves. And each was explanted in glass vial of 50 mL. And experiments were carried out twice for 18 days or 21days. Culture medium of 2ml was put in the container respectively. And 1 mL was added after 10 days. And in terms of cultivation environment, the experiment was carried out at the day length of 16 hours at the temperature of $23{\pm}1^{\circ}C$ under the white LED light of $40{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. The concentration of culture medium in the experiment I was EC 0.2, 1.0, $14dS{\cdot}m^{-1}$ and was adjusted to 0.6, 1.0, 1.4, $1.8dS{\cdot}m^{-1}$ in the experiment II. The results showed that the survival rate of plantlet was 90% at $0.2dS^2m^{-1}$, 100% at $0.6dS^2m^{-1}$, 100% at $1.0dS^2m^{-1}$. 0% at $1.4dS{\cdot}m^{-1}$, 0% at $1.8dS{\cdot}m^{-1}$. and 0% at $14.0dS{\cdot}m^{-1}$ after 7 days. With regard to the explanted potato seedling, in case of the treatment where the electrical conductivity of culture medium was adjusted to $1.0dS{\cdot}m^{-1}$, root developed 2 days after transplantation. And the plantlet vigorously grew into strong plant that had 7 leaves, length of 5cm, and fresh weight of 0.5 g after 18 days. In case of the treatment where the concentration of culture medium was adjusted to $0.6dS{\cdot}m^{-1}$, the root plantlets developed 4 days after transplantation. And those grew into plant that had 7 leaves and fresh weight of 0.2 g after 21 days. Therefore, we found that it is effective to control potato culture medium by adjusting its electrical conductivity to $0.6{\sim}1.0dS{\cdot}m^{-1}$ for the mass production of virus-free potato seedling in the microponic system.

• Journal of Korean Ophthalmic Optics Society
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• v.5 no.1
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• pp.43-48
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• 2000

It was to adjust the luminance of light by the rotation angle of the polarizes and analyzer. The luminance value Lmax, Lmin of Contrast Sensitivity could be obtained from the rotation angle ${\theta}_m$ of the average luminance($L_m$), the rotation angle(${\theta}_{max}$, ${\theta}_{min}$) of the maximum and the minimum's amplitude. $$L_{max}=I(0)e^{-2at}{\cdot}cos^2{\theta}_m(1+C_s^{-1})$$ $$L_{min}=I(0)e^{-2at}{\cdot}cos^2{\theta}_m(1-C_s^{-1})$$ We obtained the rotation angle(${\theta}_{max}$, ${\theta}_{min}$) of the polarizes and analyzer from the rotation angle ${\theta}_m$ of the average luminance($L_m$) and the Contrast Sensitivity($C_s$). $${\theta}_{max}=cos^{-1}[cos{\theta}_m{\cdot}(1+C_s^{-1})^{1/2}]$$ $${\theta}_{min}=cos^{-1}[cos{\theta}_m{\cdot}(1-C_s^{-1})^{1/2}]$$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.2
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• pp.194-201
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• 1995

In order to make clear the resistance of bag nets, the resistance R of bag nets with wall area S designed in pyramid shape was measured in a circulating water tank with control of flow velocity v and the coefficient k in $R=kSv^2$ was investigated. The coefficient k showed no change In the nets designed in regular pyramid shape when their mouths were attached alternately to the circular and square frames, because their shape in water became a circular cone in the circular frame and equal to the cone with the exception of the vicinity of frame in the square one. On the other hand, a net designed in right pyramid shape and then attached to a rectangular frame showed an elliptic cone with the exception of the vicinity of frame in water, but produced no significant difference in value of k in comparison with that making a circular cone in water. In the nets making a circular cone in water, k was higher in nets with larger d/l, ratio of diameter d to length I of bars, and decreased as the ratio S/S_m$ of S to the area $S_m$ of net mouth was increased or as the attack angle 9 of net to the water flow was decreased. But the value of ks15m was almost constant in the region of S/S_m=1-4$ or $\theta=15-90^{\circ}$ and in creased linearly in S/S_m>4 or in $\theta<15^{\circ}$ However, these variation of k could be summarized by the equation obtained in the previous paper. That is, the coefficient $k(kg\;\cdot\;sec^2/m^4)$ of bag nets was expressed as $$k=160R_e\;^{-01}(\frac{S_n}{S_m})^{1.2}\;(\frac{S_m}{S})^{1.6}$$ for the condition of $R_e<100$ and $$k=100(\frac{S_n}{S_m})^{1.2}\;(\frac{S_m}{S})^{1.6}$$ for $R_e\geq100$, where $S_n$ is their total area projected to the plane perpendicular to the water flow and $R_e$ the Reynolds' number on which the representative size was taken by the value of $\lambda$ defined as $$\lambda={\frac{\pi d^2}{21\;sin\;2\varphi}$$ where If is the angle between two adjacent bars, d the diameter of bars, and 21 the mesh size. Conclusively, it is clarified that the coefficient k obtained in the previous paper agrees with the experimental results for bag nets.

• The Pure and Applied Mathematics
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• v.25 no.1
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• pp.31-38
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• 2018

In [4], the authors show that if ${\mathbb{X}}$ is a ${\mathbb{k}}-configuration$ in ${\mathbb{P}}^2$ of type ($d_1$, ${\ldots}$, $d_s$) with $d_s$ > $s{\geq}2$, then ${\Delta}H_{m{\mathbb{X}}}(md_s-1)$ is the number of lines containing exactly $d_s-points$ of ${\mathbb{X}}$ for $m{\geq}2$. They also show that if ${\mathbb{X}}$ is a ${\mathbb{k}}-configuration$ in ${\mathbb{P}}^2$ of type (1, 2, ${\ldots}$, s) with $s{\geq}2$, then ${\Delta}H_{m{\mathbb{X}}}(m{\mathbb{X}}-1)$ is the number of lines containing exactly s-points in ${\mathbb{X}}$ for $m{\geq}s+1$. In this paper, we explore a standard ${\mathbb{k}}-configuration$ in ${\mathbb{P}}^2$ and find that if ${\mathbb{X}}$ is a standard ${\mathbb{k}}-configuration$ in ${\mathbb{P}}^2$ of type (1, 2, ${\ldots}$, s) with $s{\geq}2$, then ${\Delta}H_{m{\mathbb{X}}}(m{\mathbb{X}}-1)=3$, which is the number of lines containing exactly s-points in ${\mathbb{X}}$ for $m{\geq}2$ instead of $m{\geq}s+1$.

• Communications of the Korean Mathematical Society
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• v.12 no.3
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• pp.491-497
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• 1997

Let $C(F, M)$ and $C(S^{-1}F, S^{-1}M)$ be Cousin complexes for a modula M and a module $S^{-1}M$ over a commutative Noetherian ring with respect to a filtration F and a filtration $S^{-1}F$ respectively. In this paper, it is shown that there is an isomorphism between the Cousin complexes $S^{-1}C(F, M)$ and $C(S^{-1}F, S^{-1}M)$.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.185-198
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• 2017

Since the year 2000, the growth rate of domestic manufacturing has declined and the sales and employment have decreased. Major developed countries have established a variety of strategies to strengthen their manufacturing competitiveness, and promote manufacturing innovation through the convergence of technology and ICT. The key to manufacturing innovation is to reduce the time and cost for developing new products using modeling and simulation (M&S) technology in the product design stage. M&S industries, which belong to the top sector of the industry value chain, have a huge ripple effect across other industries. On the other hand, the competitiveness of the domestic M&S industry is weak compared to developed countries and even the definition and classification of domestic M&S companies have not been made. In this paper, by analyzing the Korea Standard Industry Classification (KSIC), five fine industry classifications included in M&S service companies were derived. In addition, the 307 M&S service companies were derived in accordance with the selection procedure of 3 steps from the 11,822 related companies. To analyze the capabilities of domestic M&S service companies, the current status of the selected M&S service companies was investigated. Considering the Korean economy's high dependence on the manufacturing industry, strengthening the competitiveness of manufacturing industry is required by enhancing the capacities and building an ecosystem in domestic M&S services for future sustainable economic growth.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.3
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• pp.293-298
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• 2014

This study conducted experiments on the reclaimed land of Saemangeum located in Jeongrabuk-do in order to gain basic information about growth characteristics and yield ability according to soil salinity. Having soil excluding salt as a control group, this study adjusted the specimens' soil salinity to level 4 and then planted four varieties including Ilmichal Corn to investigate the growth or grain yield according to salinity. About the corn establishment rate according to soil salinity, over 97% up to $3.2dS\;m^{-1}$ was established, and then, it was reduced gradually according to the increase of concentration. According to the salt concentration of soil more required growth duration from seeding to heading comparing to non-treatment salt was delayed, at $1.6dS\;m^{-1}$, two days were delayed, at $3.2dS\;m^{-1}$, four to six days were delayed differently by varieties, and at $4.8dS\;m^{-1}$, six to 10 days were delayed. About the plant fresh weight according to soil salinity, Chalok 4 and Eolrukchal indicated 93%~97% or so compared with the salt-free one at $1.6dS\;m^{-1}$, and Chalok No. 4 showed 79% at the salinity of $3.2dS\;m^{-1}$, too, and it was a relatively higher growth percentage than those of the other varieties. In terms of dried seed weight according to soil salinity, compared with the corns cultivated in the control group, averagely 12.1% was lowered at the time of cultivation at $1.6dS\;m^{-1}$, and $3.2dS\;m^{-1}$ 40% was lowered, and about 70% was lowered at $4.8dS\;m^{-1}$. According to the result of examining the point of time that dried seed start to reduce due to soil salinity with the regression equation, soil salinity which starts the reduction of grain weight is $1.67dS\;m^{-1}{\sim}2.18dS\;m^{-1}$, and it differs by varieties, and EC of 50% that the yield reduces in half is $2.96dS\;m^{-1}{\sim}4.45dS\;m^{-1}$. And the degree of influence on each of the growth factors according to soil salinity is founded to be in the order of establishment rate

• Journal of the Korean Society of Systems Engineering
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• v.5 no.2
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• pp.11-16
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• 2009

This study introduces the verification, validation & accreditation (VV&A) process for modeling & simulation (M&S). VV&A is standard process for credibility of M&S. In several countries including USA, for weapon system of Defense Development using M&S, VV&A is necessary procedures to acquire official approving for credibility of M&S. Many countries have regular recommend practice guide (RPG) and instructive for VV&A of M&S. In this study, we focus the VV&A key concepts as Department of Defense RPG of USA and give the outline of the main VV&A concepts because we don't have any available VV&A Instructive. Also, this report documents the first significant VV&A application for a MITS(M-SAM Integrate Test System) including Verification and Validation(V&V) activity and tasks.

• Horticultural Science & Technology
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• v.31 no.2
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• pp.173-178
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• 2013

Experiments were conducted to investigate the optimum concentration of nutrient solution for strawberry 'Maehyang' bred domestically for exportation in hydroponics. Nutrient solutions for strawberry, which was made by Yamazaki, were supplied electrical conductivity (EC) 0.6, 0.8, 1.2, and $1.8dS{\cdot}m^{-1}$ after planting on cocopeat medium during the experiment period. Growth of shoot of strawberries did not show any statistical differences among treatments. Fruit length showed the longest in EC 0.8 and $1.2dS{\cdot}m^{-1}$, followed by 0.6 and $1.8dS{\cdot}m^{-1}$ in the first and third cluster. It showed the shortest in EC $1.8dS{\cdot}m^{-1}$ in the second cluster but there were no significant differences among treatments in the fourth cluster. Fruit diameter did not show significant differences among treatments in the first and second cluster but was the longest in the lowest concentration EC $0.6dS{\cdot}m^{-1}$ in the third cluster. The shortest was in EC $1.8dS{\cdot}m^{-1}$ in the fourth cluster. The heaviest mean fruit weight appeared in EC 0.8 and $1.2dS{\cdot}m^{-1}$, and the lightest was in EC $1.8dS{\cdot}m^{-1}$ in the first cluster and also lightest in EC $1.8dS{\cdot}m^{-1}$ but no significant differences was found among other treatments in the second & third cluster. Also the fruit weight was significantly light in plants grown in EC $1.8dS{\cdot}m^{-1}$ than $0.6dS{\cdot}m^{-1}$ in the fourth cluster. Soluble solids content of fruit was the highest in EC $0.6dS{\cdot}m^{-1}$ in all cluster. As a result, we came to the conclusion that the optimum EC for strawberry 'Maehyang' was EC 0.8 - $1.2dS{\cdot}m^{-1}$ during low temperature season. This result will be utilized as an indicator for strawberry hydroponics.