• Journal of Bio-Environment Control
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• v.12 no.3
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• pp.132-138
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• 2003

This experiment was conducted to investigate the mass propagation system of Aster glehni FR. and to obtain the basic data for improvement of germination and seedling. The following was the results of experimentation about temperature and light conditions, and priming treatment as kinds of chemicals, their concentration and treated periods affect germination of Aster glehni FR. The germination percentage of Aster glehni FR. seed was higher in 20 and 25$^{\circ}C$ than the others, but it dropped rapidly at 30$^{\circ}C$ and didn't germinate at 35$^{\circ}C$. The first day to germination was the slowest at 15$^{\circ}C$. The germination rate of Aster glehni FR seed increased with increasing with temperatures from 15 to 25$^{\circ}C$. But the seed was rotten easily in high temperature. The germination rate was shown highest in 25$^{\circ}C$, and next was 15, 20, 30$^{\circ}C$ in order. Light treatment enhanced germination percentage, the first day to germination, germination rate and T50, but there was no significant difference. The 3 hours priming treatments had more effect on germination percentage than 30 minutes treatments as comparing averages. Aster glehni FR seeds primed in $KNO_3+K_3PO_4$ for 3 hours had most eHective on germination percentage (83.3%) and also showed shortest $T_{50{\cdot}}T_{50}$ and day of first germination was better in 30 minutes than 3 hours treatments, and most of priming treatments were better than control(non-priming seeds). While priming seeds showed shorter day of first gemination than control, there was no significant difference between 30 minutes and 3 hours treatments.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.31 no.2
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• pp.87-95
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• 2018

This paper introduces a new explicit spectral element method for the simulation of SH-waves in semi-infinite domains. To simulate the wave motion in unbounded domains, it is necessary to reduce the infinite extent to a finite computational domain of interest. To prevent the wave reflection from the trunctated boundaries, perfectly matched layer(PML) wave-absorbing boundary is introduced. The forward problem for simulating SH-waves in PML-truncated domains can be formulated as second-order PDEs. The second-order semi-discrete form of the governing PDEs is constructed by using a mixed spectral elements with Legendre-gauss-Lobatto quadrature method, which results in a diagonalized mass matrix. Then the second-order semi-discrete form is transformed to a first-order, whose solutions are calculated by the fourth-order Runge-Kutta method. Numerical examples showed that solutions of SH-wave in the two-dimensional analysis domain resulted in stable and accurate, and reflections from truncated boundaries could be reduced by using PML boundaries. Elastic wave propagation analysis using explicit time integration method may be apt for solving larger domain problems such as three-dimensional elastic wave problem more efficiently.

• Korean Journal of Plant Resources
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• v.24 no.2
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• pp.168-173
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• 2011

This study was carried out to optimize the embryogenic callus induction and plant regeneration from mature seeds of Sorghum bicolor. The effect of growth regulators was investigated on formation of embryogenic callus. The highest frequency of embryogenic callus was observed when the mature seeds were cultured on B5 medium supplemented with 2 mg/L 2,4-Dichlorophenoxyacetic acid (2,4-D). The highest frequency of plant regeneration from embryogenic callus was observed on MS medium with 0.5 $mg\;l^{-1}$ 6-benzyl amino purine (BAP) and 0.25 $mg\;l^{-1}$ indole-3-butyric acid (IBA) to optimize the shoot regeneration. High concentration of BAP (1 $mg\;l^{-1}$) supplemented with IBA (0.25 $mg\;l^{-1}$) was effective combination for shoot multiplication. MS medium supplemented with 1 $mg\;l^{-1}$ IBA was found to be the most effective for inducing roots. Normal rooted plantlets were transferred to the greenhouse for hardening with over 90% survival rate. Hence, this reproducible protocol could be useful for mass propagation and genetic transformation of S. bicolor.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.23-23
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• 2018

본 연구는 참우드풀과 우드풀의 중간형으로 알려진 좀우드풀(Woodsia intermedia Tagawa)의 전엽체 증식 및 포자체 형성을 위한 기내 외 번식조건을 구명하고자 수행되었다. 실험재료는 포자를 발아시켜 획득한 전엽체를 8주 간격으로 계대배양하면서 확보하였다. 전엽체 증식에 적합한 배양조건을 탐색하고자, 전엽체 300mg을 다진 후 배지종류(Knop, 1/4, 1/2 및 1MS)와 배지구성물질(sucrose와 활성탄)의 농도를 달리하여 8주간 배양하였다. 배양실은 온도 $25{\pm}1.0^{\circ}C$와 광도 $30{\pm}1.0{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$(16/8h)로 조절되었다. 연구결과, Knop배지에서 생체중이 2.4g으로 전엽체의 증식이 가장 왕성하였다. 한편 MS계열 배지는 농도에 관계없이 매우 저조한 증식을 보였다. Sucrose는 0.5%를 첨가한 배지에서 생체중의 증가량이 가장 컸으며, 활성탄은 첨가농도에 관계없이 유사한 증식수준을 나타냈다. 포자체 형성에 적합한 토양조건을 확인하고자, 인공토양(원예상토, 피트모스, 펄라이트 및 마사토)의 비율을 달리하여 5종류의 혼합토양을 조성하였다. 혼합토양을 사각분($7.5{\times}7.5{\times}7.5cm$)에 충진하고, 준비된 전엽체 1g을 10초간 분쇄한 다음 토양표면에 분주하여 11주간 재배하였다. 재배환경은 온도 $25{\pm}1.0^{\circ}C$, 광도 $43{\pm}2.0{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$(16/8h) 및 습도 $72{\pm}2.0%$로 조절되었다. 연구결과, 모든 처리구에서 포자체의 형성이 확인되었으며, 특히 원예상토와 마사토를 2:1(v:v)로 혼합한 토양에서 포트당 421.0개의 많은 포자체가 형성되었다. 다음으로 원예상토와 펄라이트를 2:1(v:v)로 혼용한 토양, 원예상토, 피트모스, 마사토를 1:1:1(v:v:v)로 혼합한 토양, 원예상토 단용, 원예상토, 피트모스, 펄라이트를 1:1:1(v:v:v)로 혼합한 토양 순으로 각 228.0, 203.3, 126.8, 91.5개 형성되었다. 따라서 좀우드풀의 포자체를 대량으로 생산하기 위해서는 원예상토와 마사토를 2:1(v:v)로 혼용한 토양에 전엽체를 분주하여 재배하는 방법이 효과적일 것으로 판단된다.

• The Journal of Fisheries Business Administration
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• v.25 no.2
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• pp.1-46
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• 1994

The Purpose of this research is to analyze and discuss the development of yellowtail aquaculture industry in Japan and its management structure. The research includes the following : (a) It confirms the industrial conditions of yellowtail aqaculture which has a national technical and mass production system that has been developed at great speed. (b) It analyzes yellowtail aqaculture development from a family - oriented management to a large scale production. (c) It examines how the fisheries cooperatives harmonized their role with the object of individual aqaculture management and aqaculture fishing ground management. The reasons for this study focusing on the yellowtail aqaculture industry of Japan are : (a) The yellowtail aqaculture is regared as a typical field in aqaculture because it reflects the general aqaculture history, quantity of fisheries aqaculture product, the number of fishermen involved in this industry, technology , and the live and fish market formation in Japan. (b) The aqaculture has the most powerful entrepreneurial in financial and management style. The aqaculture industry also has a most individual management style which includes planned production and shipping strategy. This research has attempted to study the industrial processes of fisheries aqaculture industry and its management development, and focused on the yellowtail aqaculture industry of Japan. This work also includes data about the aqaculture management of fisheries cooperatives and case by case analysis of aqaculture production. The following results were obtained from this study : First, even though ocean, weather conditions, and widespread propagation of places suitable for aqaculture in Japan were crucial factors in aqaculture development, it must be pointed out that fisheries policy in Japan changed from "catching" in the 1960s to "cultivating". Second, the widespread course of fisheries cultivating technology in Japan has had two characteristics. One is that early aqaculture technology spread to the southern part of Japan and the other is that the metal nets were widely used in the northern part in the 1970s. Japan's yellowtail aqaculture industry's overproduction was due to metal nets. However, the use of mwtal nets also contributed to the improvement of aqaculture and the strategic aspects of aqaculture management. In addition, it should be stressed that Kagoshima prefecture as the pioneer of metal nets contributed to fisheries aqaculture development in japan. Third, as aqaculture technology developed, entrepreneurial qualities of aqaculture management also developed this field into a large scale business. Even though it is not clear, large scale management of yellowtail aqaculture shows evidence of superiority over small andmedium - size management of yellowtail aqaculture. Fourth, yellowtail aqaculture management in Japan hascontributed to the production system and aqaculture strategy to meet consumers' needs and market demands from weather - oriented trational fisheries industry, which overcame their overproduction structure. Fifth, Japanese fisheries cooperative played very important roles in the prevention of fishing grounds production from destruction and in promoting suitable aqaculture facilities so that aqaculture could grow continually.ld grow continually.

• Journal of Korea Foresty Energy
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• v.22 no.2
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• pp.1-17
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• 2003

Populus species have been as a model species in tree breeding and we have enormous varieties resulting from the poplar breeding because of their fast growth performance and short rotation age. New varieties developed in Korea are common italian poplar(P euramericana, I-214, I-476), P euramericana“Eco 28”(Italian poplar No.1) and p. deltoides“Lux”(Italian poplar No.2), which were introduced from foreign countries. As hybrid polars, Hyun-Sasi(p. alba ${\times}$ P. glandulosa No.1, No.2, No.3, No4.), P. nigra x P. maximowiczii and P. koreana x P. nigra val. italica, were developed, and P. davidiana was selected as the result of selection breeding The total plantation areas covered with the new varieties are 935,162ha that include 745,773ha of P. euramericana, 184,636ha of P. alba x P. glandulosa, and other new varieties are 4,735ha. The new poplars are contributed to increase farmer's income as well as bare land tree-planting in Korea. The technologies associated with the poplar species were developed, such as the determination of optimum site for new the poplar species, the crossing method between incompatible poplar species, and the vegetative mass propagation. In the future, poplar species will be considered for phytoremediation species at contaminated areas such as landfill sites or with lives stock's waste water as well as wood production, a shade tree like road-side tree and public park tree.

• Korean Journal of Plant Resources
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• v.30 no.4
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• pp.372-377
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• 2017

This research was performed to develop mass propagation method of Alpine modest primrose (Primula modesta var. hannasanensis T.Yamaz.) for improving the conservation and utilization of the species. Seeds were collected on August 2011 in Jeju-city and well-selected seeds were dry-stored at $4{\pm}1.0^{\circ}C$. Seed size ranged $0.44{\pm}0.07{\times}0.61{\pm}0.04mm$, and weight of 1,000 seeds was $51.78{\pm}0.021mg$. Thus the seed was classified as 'dwarf seeds'. As the result of dormancy characteristics, moisture content of freshly matured seeds increased rapidly by water-soaking treatment and seeds did not germinate at $20^{\circ}C$ for 4 weeks under the light condition. Therefore, seeds were estimated to have physiological dormancy. Germination conditions of dry-stored seeds were found to be $20^{\circ}C$ and light condition, and seeds did not germinated under dark condition regardless of all temperature regimes. Therefore, Alpine modest primrose seed was considered as photoblastic type. Percent germination (PG) and germination energy (GE) were greatly improved by soaking the seeds in $GA_3$ and kinetin for 24 hours. Especially, 200~500 mg/L $GA_3$ treatment resulted in the highest PG (95.5%) and GE (98.3%). So, chemical treatment such as $GA_3$ was thought to be a useful method for raising seedling uniformly.

• Korean Journal of Plant Resources
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• v.15 no.3
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• pp.269-278
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• 2002

To establish the mass propagation methods of Weigela subsessilis,, a promising native plant species for horticultural use, several factors influencing rooting from stem cuttings were evaluated. Softwood cuttings showed best rooting rate, 70~77%, in all the cutting media tested, 2.8 times more than hardwood cuttings in which perlite was best medium. The rooting from hardwood cuttings was promoted by higher concentration of all growth regulators used,500 mg.L$^{-1}$ NAA being the best with 80%. More than 80% of softwood cuttings treated by growth regulators produced roots, especially 100, 500, and 1000mg.L$^{-1}$ NAA producing 97％. Roofings from semi-wood cuttings was enhanced by all the growth regulators, except 1000 mg.L$^{-1}$ concentration in which rooting was reduce. Higher rooting rate was obtained by higher concentration and longer soaking duration of NAA in case of hardwood cutting. Softwood cutting showed 100 ％ rooting by soaking treatment with 500 mg.L$^{-1}$ NAA for 3 min. Rooting rate of semi-hardwood cuttings was promoted by higher concentration and longer soaking with growth regulators, However, the degree of improvement was lower than soft and hardwood cutting.

• Korean Journal of Medicinal Crop Science
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• v.11 no.1
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• pp.46-52
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• 2003

This experiment was conducted to investigate the propagation for mass production of Acanthopanax koreanum NAKAI utilized for health food and medicine material. Germination rate of A. koreanum seeds were 64% when seeds were stored at 15 for 60 days and then were treated with 50 ppm of kinetin and dormancy were broken at 5 for 60 days. Rooting rates of green-wood cuttings treated with IBA 100 ppm, NAA 50 ppm, and IAA 100 ppm were 61.7, 56.7, and 60.0%, respectively. Rooting rates of greenwood cuttings treated with Rooton in scoria + horticulture media and volcanic ash were 76.7 and 66.7%, respectively. Survival rate of seedlings planted on Aug. 10 was highest (96%) under 75% shading net while shoot growth was best under 55% shading net. Survival rate of seedlings planted on May 2 was highest (91%) 55% shading net, and shoot growth was also best 55% under shading net.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.1
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• pp.73-80
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• 2004

In this paper, the implementation and embedding method of the existing air-filled waveguide-filters at millimeter-wave on general PCB substrate is introduced by systematically inserting the vias inside waveguide and mathematically manipulating the simple equations obtained ken the classical circular-post waveguide filter design. All the metal structures placed vertically such as side wall fur perfect ground plane and circular-post for signal control in the air-filled WR-22 waveguide are replaced with several types of via for constructing the bandpass-filter. Side wall and poles inside waveguide are realized by placing a series array of via and tuning the via diameter. The lengths of x, y, z axis are reduced in proportion to root square of employed substrate dielectric constant and especially the length of z axis can be more reduced due to the characteristics of the wave propagation. Because the mass production on PCB is possible without fabricating a large-scaled metal waveguide of WR-22 as input/output ports at millimeter-wave regime, the manufacturing cost is reduced considerably. Finally, when using multilayer process like LTCC for small-sized module, it is one of advantages to use only one layer f3r the filter fabrication. To evaluate the validity of this novel technique, order-3 Chebyshev BPF(Bandpass-Filter) centered at 40 GHz-band with a 2.5 ％ FBW (Fractional Bandwidth) were used. The employed substrate has relative dielectric constant of 2.2 and thickness of 10 mil of Rogers RT/Duroid 5880. Accroding to design and measurement results, a good performance of insertion loss of 2 ㏈ and return loss of -30 ㏈ is achieved at full input/output ports.