• Journal of Plant Biotechnology
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• v.38 no.1
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• pp.15-21
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• 2011

We developed 14 transgenic lines of Chinese cabbage (Brassica rapa) harboring the T-DNA border sequences and CryIAc1 transgene of the binary vector 416 using Agrobacterium tumefaciens-mediated DNA transfer. Six lines had single copy cryIAc1 gene and four of them contained no vector backbone DNA. Of the left border (LB) flanking sequences six nucleotides were deleted in transgenic lines 416-2 and 416-3, eleven nucleotides in line 416-9, and 65 nucleotides including the whole LB sequences in line 416-17, respectively. And we defined 499 bp of genomic DNA (gDNA) of transformed Chinese cabbage, and blast results showed 96% homology with Brassica oleracea sequences. PCR with specific primer for the right border (RB) franking sequence revealed 834 bp of PCR product sequence, and it was consisted of 3' end of cryIAc1, nosterminal region and 52 bp of Chinese cabbage genomic DNA near RB. RB sequences were not found and the 58 nucleotides including 21 bp of nos-terminator 3' end were deleted. Also, there were deletion of 10 bp of the known genomic sequences and insertion of 65 bp undefined genomic sequences of Chinese cabbage in the integration site. These results demonstrate that the integration of T-DNA can be accompanied by unusual deletions and insertions both in transgenic and genomic sequences.

• Korean Journal of Weed Science
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• v.18 no.3
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• pp.205-213
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• 1998

This experiment was carried out to produce herbicide resistant potatoes hawing only chimeric phosphinothricin acetyltransferase (PAT) genes without using antibiotic selectable marker. The pDY502 vector having only PAT gene was reconstructed for transformation of potato. The reconstructed vector was introduced to Agrobacterium tumefaciens MP90 disarmed, and they were used for potato transformation. Hormonal requirement for plant regeneration from leaves and stem explants of potato was investigated. From this experiment, MS medium treated with IBA 0.1 mg/L + BA 0.5 mg/L was the best for potato regeneration, and the ratio of shoot regeneration was 54% for leaf and 46% for stem in that condition. For transformation, explants of potato leaves and stems were cocultured with A. tumefaciens MP90 containing reconstructed vector harvoring only PAT gene. When the potato explants were placed on various concentrations of bialaphos and all the potato explants were dead on medium with over 5.0mg/L bialaphos. By this selection methods, the explants cocultured with Agrobacterium produced the putative transgenic shoots on medium with 5mg/L bialaphos treatment after 3-4 weeks. Second selection was performed by transferring the shoot tips of putative transgenic to medium containing 20mg/L of bialaphos. The shoot tips grew well on the second selection medium, indicating the production of successful transgenic plants. But normal shoots were dead in same cytotoxic medium. Incorporation of the PAT gene into transgenic potatos were confirmed by PCR analysis of DNA and Southern hybridization. These results show that the PAT gene can serve as a selectable marker and herbicide resistant genes for transformation of potato.

• Horticultural Science & Technology
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• v.32 no.3
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• pp.310-317
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• 2014

This study was conducted to find basic information for the research of morphological dormancy in seeds of two genera (Heloniopsis and Thalictrum) native to Korea. Seeds of Heloniopsis koreana, Heloniopsis tubiflora, Thalictrum rochenbrunianum, Thalictrum uchiyamai, and Thalictrum coreanum were collected, and embryo morphology and seed germination were investigated. All seeds of five species had underdeveloped embryos which occupied about 10-20% of the full seed length at maturity. The seeds of H. koreana and H. tubiflora had rudimentary embryos. The seeds of T. rochenbrunianum, T. uchiyamai, and T. coreanum had intermediate type between rudimentary and linear embryo. The small embryos of all seeds of five species grew to a critical length before radicles emerge from the seeds. At 30 days after sowing, the seeds of H. koreana and H. tubiflora germinated to 22.7% and 40.7%, respectively. On the other hand, the seeds of T. rochenbrunianum, T. uchiyamai, and T. coreanum germinated to 12.5%, 3.3%, and 0%, respectively. If embryo growth and germination in seeds are completed in approximately 30 days, the seed are said to have morphological dormancy (MD). However, if the seeds require > 30 days for germination, they are considered to have morphophysiological dormancy (MPD). Thus, the seeds of H. koreana and H. tubiflora had about 78% and 60% MPD, respectively. On the other hand, the seeds of T. rochenbrunianum, T. uchiyamai, amd T. coreanum had about 87%, 96%, and 100% MPD, respectively. There was a different level of dormancy (MD and MPD) within the same seed population examined. Therefore, germination of the seeds was delayed due to the underdeveloped embryos. This result could contribute to determine morphological seed dormancy and germination mechanism in seeds of the Korean Peninsula.

• Journal of The Korean Society of Grassland and Forage Science
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• v.10 no.1
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• pp.42-47
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• 1990

Silage productivity of 7 corn and 3 sorghum hybrids was determined at two planting dates differing in rice black-streaked dwarf virus (RBSDV) infection rates in the southern part of Korea where RBSDV is prevalent. 1. Percent stand was similar between two planting dates, but that of corn hybrids (85.0-99.5 %) was higher compared with sorghum (59.8-82.3 %). Culm length of corn hybrids at April 23 planting was longer compared with May 20 planting, but that of sorghum hybrids was similar between two planting dates. 2. RBSDV infection rate of corn hybrids at April 23 planting was lower compared with May 20 planting, but sorghum was not infected at both planting dates. Among corn hybrids Suweon 19 was most severely infected, but Suweon 99 was least infected at both planting dates. 3. Percent ear bearing plants and earltotal dry matter (TDM) ratio of corn hybrids at April 23 planting was higher than those of May 20 planting. Among the corn hygrids percent ear beraring plants, ear/TDM ratio of Suweon 19 was lowest at both planting dates due to severe RBSDV infection. Ear/TDM ratio of sorghum hybrids was below 17.8 % due to sterility and partially bud damages. 4. Silage yield at April 23 planting was higher than that at May 20 planting and sorghum hybrids outyielded corn hybrids. Silage yield of Suweon 19 and Jinjuok was lowest due to severe RBSDV infection. 5. Crude protein was similar regardless planting dates, species, and varieties except the lowest P 931. Ether extract at April 23 planting was lower then that at May 20 and corn was lower compared with sorghum hybrids. Crude fiber and nitrogen free extracts(NFE) was similar between planting dates. Crude fiber of corn was lower, but NEF was higher compared with sorghum, but similar among hybrids in a species. 6. In vitro dry matter digestibility (IVDMD) at May 20 planting was higher than that of April 23 planting and corn was higher than sorghum hybrids. Digestible dry matter (DDM) of both corn and sorghum at April 23 planting was higher than that of May 20 planting. At April 23 planting DDM of all corn and sorghum hybrids was similar, but DDM of Suweon 19 and Jinjuok was lower than other corn and sorghum hybrids.

• Journal of The Korean Society of Grassland and Forage Science
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• v.19 no.3
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• pp.211-220
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• 1999

The corn is mostly planted in mid-April in single-cropping silage system if possible, however, in a double-cropping silage system, the corn planting date is delayed until after the mid-May. The objective of this study was to evaluate agronomic characteristics and forage performance of the eight government recommended corn hybrids for silage at two dates of planting. Split-plot design replicated three times was used, that is, main plots were planting dates, sub-plots were eight hybrids at Suweon in 1997. Days from planting to silking of optimum planting was 84 days and that of late was 69 days. The difference in silking day among the hybrids was 6 days at optimum planting and 2 days at late planting. Plant height of optimum planting corn was higher than that of late one, however, ear height and stem diameter of optimum planting were lower than those of late planting corn. Among the corn hybrids tested, plant heights of 'P3156' and 'P3163' were higher than those of the other hybrids. Ear height of 'DK713' was the lowest among the corn hybrids and stem diameter of 'P3394' was thicker than that of the other hybrids. European corn borer(ECB) damage(16.6%) at optimum planting was lower than that(49.9%) of late, however, there were no significant ECB damage differences among the corn hybrids tested. Whole plant dry matter(DM) contents of 'P3525', 'P3394' and 'P3352' hybrids were higher than those of the other corn hybrids at harvest. Ear percentages of the total dry matter(DM) of 'P3394' and 'P3156' were higher than those of the other corn hybrids. Dry matter(DM) and total digestible nutrients(TDN) yields(19,696 and 14,621kg/ha) at optimum planting were higher than those (17,163 and 12,570kg/ha) of late planting, while there were no significant differences in DM and TDN yields among the corn hybrids tested. And those hybrids with greater proportion of grain in the whole plant have higher DM and TDN yields. Correlation coefficients for days from planting to silking with DM and TDN yields were $0.84^{**}$ and $0.87^{**}$, and those for ear percent were $0.86^{**}$ and $0.87^{**}$. Results of this study indicate that optimum planting date(15 April) is better than late planting date(16 May) in agronomic characteristics and forage production of silage corn. Days from planting to silking and ear percent as welI as other characters are important factors screening the corn hybrid for silage.

• Horticultural Science & Technology
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• v.30 no.4
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• pp.437-441
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• 2012

This study was conducted to find out the optimum container for increasing acclimatization rate of in vitro mass propagated plantlets of Ever-bearing strawberry (Fragaria ${\times}$ ananassa Duch.) via bioreactor. Four types of containers were used such as transparent plastic container (TPC), plug tray (PT), I-pot (IP), and black vinyl pot (BVP). Number of date maintaining soil water content above 10% was five days in TPC, three to four days in BVP, two days in PT, and one day in IP. Survival rate of plantlets was 80% in BVP, 70% in TPC, 55% in IP, and 15% in PT. In TPC, growth increment of plantlets was the greatest among all the tested containers and the lowest in IP. Numbers of runner per plant were 3.3 in BVP, 2.9 in TPC, 1.6 in PT, and 1.2 in IP. Total cost was 44,405,300 won/10 a in BVP, resulting in reducing more 6,659,400 won/10 a than IP's (51,064,700 won/10 a). Around 102,718 plants/10 a were produced by using BVP, suggesting that 30,265.1 plants/10 a more could be produced than IP (72,452.9 plants/10 a). Production cost per plant was 432.3 won in BVP, resulting in reducing 272.5 won than IP's (704.8 won). As a result, BVP was appropriate for acclimatization of in vitro plantlets through bioreactor system.

• Journal of Biomedical Engineering Research
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• v.25 no.5
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• pp.403-414
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• 2004

In the accompanying paper, we proposed a real. time volumetric imaging method using a cross array based on receive dynamic focusing and synthetic aperture focusing along lateral and elevational directions, respetively. But synthetic aperture methods using spherical waves are subject to beam spreading with increasing depth due to the wave diffraction phenomenon. Moreover, since the proposed method uses only one element for each transmission, it has a limited transmit power. To overcome these limitations, we propose a new real. time volumetric imaging method using cross arrays based on synthetic aperture technique with linear wave fronts. In the proposed method, linear wave fronts having different angles on the horizontal plane is transmitted successively from all transmit array elements. On receive, by employing the conventional dynamic focusing and synthetic aperture methods along lateral and elevational directions, respectively, ultrasound waves can be focused effectively at all imaging points. Mathematical analysis and computer simulation results show that the proposed method can provide uniform elevational resolution over a large depth of field. Especially, since the new method can construct a volume image with a limited number of transmit receive events using a full transmit aperture, it is suitable for real-time 3D imaging with high transmit power and volume rate.

• The Korean Journal of Air & Space Law and Policy
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• v.26 no.1
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• pp.215-239
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• 2011

We are now entering the era of Commercial Space Transportation with the rapid commercialization of space. Commercial Space Tourism will be realized first of all in the commercial space transportation and the spacecraft is developing for it led by private enterprise such as Virgin Galatic and XCOR Aerospace. The spacecraft for space tourism is developed as Reusable Launch Vehicle(RLV). RLV Spaceship I & II manufactured by the Scaled Composites for Virgin Galatic had completed experimental flight successfully and is going to put to the operation for space travel around the year 2012. In our country, Yecheon Astro-Space Center located in Yecheon, Kyungbuk Province, signed a binding-MOU with XCOR Aerospace and going to start space travel in the year 2013 with the spacecraft LYNX MARK-II. Thus, now space travel has become a reality to us. But it is also reality that there's no study by legal basis preparing for the space tourism domestically and internationally. In this regards, this thesis dealt with legal issues related to space tourism. These are as follows : (1) the applicabe law issue that is which law between air law and space law will apply, (2) the status of space tourist issue that is space tourist can be considered as personnel of a spacecraft and/or space flight participant and has the duty to obey the order of the captain of spacecraft, (3) the responsibility of the government for the non-governmental entities such as private enterprise which involved in space tourism in case space accident occurs during the space travel, (4) license permit and supervision issue by the government (In this point, for activating the market of the space tourism, I think it is essential to guarantee the safety of the spacecraft by the government authority, though U. S. government declared that it has not certified the launch vehicle as safe for carrying crew or space flight participants), (5) registration issue, (6) space insurance issue. For all the issues mentioned above, I have studied the existing international treaties and several country's domestic law to the space by referring U.S's Commercial Space Launch Amendment Act of 2004 and New IGA of 1998 and concluded that uniform legal regime to govern these issues should be established domestically and internationally in the near future.

• The Korean Journal of Air & Space Law and Policy
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• v.25 no.1
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• pp.205-236
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• 2010

This article deals with international space law for the environmental protection in outer space especially for space debris arising from space activities. After studying 1967 Outer Space Treaty, 1968 Rescue Agreement, 1972 Liability Convention, 1975 Registration Convention and 1979 Moon Agreement, we could find few provisions dealing with space environment in those treaties. During the earlier stages of the space age, which began in the late 1950s, the focus of international law makers was the establishment of the basic rules of space law governing the states' activities in outer space. Consequently the environmental issues and the risks that might arise from the generation of the space debris did not receive priority attention within the context of the development international space law. Although the phrases such as 'harmful contamination', 'harmful interference', 'disruption of the environment', 'adverse changes in the environment' and 'harmfully affecting' in relation to space environment were used in 1967 Outer Space Treaty and 1979 Moon Agreement, their true meaning was not definitely settled. Although 1972 Liability Convention deals with compensation, whether the space object covers space debris is unclear despite the case of Cosmos 954. In this respect international lawyers suggest the amendment of the space treaties and new space treaty covering the space environmental problems including the space debris. The resolutions, guidelines and draft convention are also studied to deal with space environment and space debris. In 1992 the General Assembly of the United Nations passed resolution 47/68 titled "Principles Relevant to the Use of Nuclear Power Sources in Outer Space" for the NPS use in outer space. The Inter-Agency Space Debris Coordination Committee; IADC) issued some guidelines for the space debris which were the basis of "the UN Space Debris Mitigation Guidelines" approved by COPUOS in its 527th meeting. In 1994 the 66th conference of ILA adopted "International Instrument on the Protection of the Environment from Damage Caused by Space Debris". Although those resolutions, guidelines and draft convention are not binding states, there are some provisions which have a fundamentally norm-creating character and softs laws.

• Journal of Bio-Environment Control
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• v.20 no.4
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• pp.326-332
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• 2011

The growth and bolting characteristics of spring Chinese cabbage cultivars at two night-time temperature treatments such as $5^{\circ}C$ and $10^{\circ}C$ during seedling stage were investigated to establish a safe environmental management strategy for raising seedlings. The low night-time temperature treatments were applied at 5, 10, and 15 days after sawing and the treatment durations were 5, 10, and 15 days in each of treatment beginning. The growth of seedlings in all the tested cultivars were linearly reduced as the treatment duration was extended and no symptoms of bolting were found. The reduction rate in seedling growth of 'Chunkwang' reached to 59.3% at most by 15 days of $5^{\circ}C$ treatment when it be compared to that of control. However, no symptoms of bolting were shown in the treatments of two night-time temperatures until the harvest at 90 days after sawing, indicating that the vernalization effect by low night-time temperature could be mitigated by subsequent day-time optimal temperature management. This study showed that the major spring Chinese cabbage cultivars require more ultimate level of low night-time temperature treatment for the vernalization than this study. It is also supposed that the optimal day-time temperature management can reduce or delay the rate of bolting, even if the seedlings were exposed to short-term low temperature below $5^{\circ}C$ during night-time.