• Horticultural Science & Technology
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• v.29 no.2
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• pp.81-86
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• 2011

The effects of girdling on fruit quality and cold resistance of 'Kyoho' grapes were investigated. Girdling treatment was conducted on the trunk at 10 cm above ground with 1 cm width and grapes were harvested at 90 and 110 days after full bloom to compare the fruit quality. First harvesting rate in girdling treatment was higher than that in non-girdling treatment and coloration was also higher in girdled vines at the final harvest. In other words, coloring process of grape was promoted and enhanced by girdling, but this effect of coloring improvement was decreased after successive girdling treatment. Fruit quality showed no difference between the treated and non-treated berries, but fruit cracking rate was lower in girdled treated berries. Girdled trees were weakened and suffered from freezing damage. Especially, most grapevines withered up after being girdled for three consecutive years. Although girdling had effect on improving the berry coloring significantly, the effect wore off with continuous girdling. And it was possible that consecutive girdling leaded to wither and growth suppression especially in grapevines. These adverse effects may make the continuous girdling technique unsuitable in practice for 'Kyoho' grape.

• Korean Journal of Food Science and Technology
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• v.35 no.5
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• pp.783-790
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• 2003

Tetranychus urticae Koch and Panonychus ulmi Koch were identified as quarantine pests in apple samples and were controlled soon after the commercial treatment of methyl bromide (MeBr) and with irradiation doses $(0.5{\sim}3kGy)$ after irradiation. The physical qualities of apples, such as rotting, withering, weight changes, hardness, and color, were apparently affected by MeBr. Furthermore, more than 2 kGy irradiation resulted from the lapse of storage time. Associated with the physical qualities of stored apples, irradiation and fumigation for quarantine purposes were more adequate after 40 days of storage at $0{\pm}1^{\circ}C\;(85{\pm}2%\;RH)$ immediately following harvest, rather than soon after harvest. Less than 1 kGy irradiation, based on its accumulated control effect on pests, can potentially be applied as a quarantine procedure without causing significant changes in the physical qualities of fresh apples, in contrast to MeBr.

• Journal of Korean Society of Forest Science
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• v.85 no.2
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• pp.260-270
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• 1996

Structure and dynamics of Pinus densiflora community in Mt. Kaya were studied to provide the information needed for management of Pinus densiflora forest in the southern inland of Korea. Stratification structure of Pinus densiflora community in the lower and middle slope consisted of tree layer(10~15m), subtree layer(4~10m), shrub layer(1~4m), and herb layer(below 1m), while in the rock zone of ridge and top area consisted of tree layer(7~10m), subtree layer(2~7m), shrub layer(1~2m), and herb layer(below 1m). According to the diameter distribution of tree species in Pinus densiflora community, secondary Pinus densiflora forest will gradually decline. Its forest may be replaced by Quercus mongolica, Quercus serrata, Carpinus laxiflora, C. cordata, and Fraxinus rhychophylla in the lower slope, and by Quercus mongolica in the middle slope. Pinus densiflora forest has its seedlings and saplings in ridge and top area, so it may be sustained. By taking cores from Pinus densiflora trees in research area, it could be obtained that in the lower and middle slope, age of Pinus densiflora forest was about 80~90 years old. When the age of its trees was about 72~80 years old, withering trees of standing dead occurred. Disturbance regime of Pinus densiflora community in Mt. Kaya consisted of standing dead, uprooting and limbfall, these were 70.6%, 17.6% and 11.8% respectively. It takes about 100~110 years for advance growth of Pinus densiflora in ridge and top area to reach tree layer. During the period, it has twice chances of disturbance in standing dead. Annual diameter growth of Pinus densiflora was 2.45~2.9mm in the lower and middle slope, while it was 1.75mm in ridge and top region, by measuring cores.

• Korean journal of applied entomology
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• v.53 no.3
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• pp.311-315
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• 2014

Lantern fly(Lycorma delicatula) is a major invasive pest that causes withering symptom of agricultural crops by sucking tree sap and sooty mold symptom by producing honeydew. This study was conducted to investigate the occurrence pattern of lantern fly in grape orchards in Gyeonggi area and the effect of winter temperature on L. delicatula egg survival during 2010 to 2013. In Gyeonggi areas, overwintered L. delicatula eggs began to hatch from early May and nymphs peaked in mid May. Adults emerged from late July and laid eggs until early November. The survival of L. delicatula eggs during overwintering was largely affected by winter temperatures. The relationship between the number of days below a threshold temperature (x) in January and the survival rate of overwintering L. delicatula eggs (y) was using linear regression model. The best model selected by the lowest RSS (residual sum of square) between predicted and actual survival was y = -1.0486 x + 94.496 ($R^2=0.7067$) with $-11^{\circ}C$ of threshold temperature. These results should be helpful to conduct L. delicatula management programs, since the results provided relivable prediction for the winter survival of L. delicatula eggs and the phenology of egg hatch in the spring.

• The Korean Journal of Ecology
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• v.26 no.4
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• pp.181-188
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• 2003

Frequencies of each size class, annual change of tuber state and above ground/belowground rate in sect. Pes-gallinaceua group of Corydalis (Fumariaceae) were studied to clarify spring ephemeral´s growth characteristics from 1999 to 2000 in Namhansansung area. Shoot grew from the tuber corresponding with soil thawing in the early growth season, and the deeper tuber was located in soil, the later shoot germinated. Shoot appeared in middle March and died early in May, and the period of total growth season was 45 days. Frequencies were 40% (in total dry weight) or 53% (in tuber´ dry weight) in the smallest size class, and 93% (in total dry weight) or 96% (in tuber´ dry weight) below medium size, therefore, almost all of plants were small. Specific gravity of tuber (SGT) gradually decreased from late growth season to the time that leaf unfolded in next year. At this time, the value of SGT was 0.14. Thereafter, SGT increased to 0.42 at withering time of aboveground part. During growth season, the SGT of flowering plants was lower than that of non-flowering plants. And SGT difference between flowering plants and non-flowering plants was significant at 1% level. In the late growth season, SGT decreased along the increase of tuber volume. The tuber volume roughly increased along the leaf area but there was no a conspicuous trend. Shoot/tuber rate had nothing to do with tuber volume. SGT decreased and leaf area increased along the tuber dry weight, and tendencies of increase or decrease were conspicuous. Therefore, the smaller the plants were, the larger organic matter accumulated in tuber during a growth season. Shoot/tuber rates were various along each plant.

• Korean Journal of Environment and Ecology
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• v.20 no.4
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• pp.425-435
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• 2006

The objectives of this research were to investigate the drought resistance as well as the growth of Wisteria floribunda seedlings with the soil water conditions. The seedlings for the research were grown in pots with strict water content control on a frame located outdoors. During the experiments, the soil water contents were adjusted to 5, 10, 20, 30, 40, 50, 60, and 70%. In addition, the effects of Rhizobium inoculation on the growth of seedlings were investigated. The experimental results are summarized as follows: 1. The seedlings in the pots with 5% soil water content withered to death due to the water stress. Withering or any distinct growth was not observed from the seedlings in the 10% soil water content. It can be inferred from these results that about 5% of soil water content is the wilting point of W. floribunda seedlings and about 10% is the critical soil water content of its growth in this experiment soils. Therefore, it seems that W. floribunda possesses a good drought resistance. 2. From the analyses of the main growth parameters such as stem elongation, diameter growth, leaf area growth and total dry weight, it was found that the seedling growth can be improved with increasing soil water contents. The relation between each growth parameter(Y) and the soil water contents(W) was well described by a quadratic equation, $Y=a+bW+cW^2$. 3. In soil water contents higher than 20%, the seedling growth(Y) was remarkable along with-its extended growing period, and related to the growing period(D) by a quadratic equation, $Y=a+bD+cD^2$. 4. The artificial inoculation of Rhizobiun promoted the growth of Wisteria floribunda seedlings. 5. Rhizobium was found to be more readily inoculated and to form more root nodules compared to seedlings grown in higher soil water contents.

• Korean Journal of Plant Resources
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• v.16 no.3
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• pp.212-217
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• 2003

This study was conducted to search for possible cultivation area of Rhodiola sachalinensis as well as to obtain the basic information of growth characteristics. One­year old nursery plants of Rhodiola sachalinensis were collected from Yonbyeon Hongkyungcheon development society in China This expriment was evaluted in three areas according to sea level such as plain region in Cheongwon(50m at sea level), mid­mountainous region in Jecheon(350m at sea level) mountainous region in Banyans(650m at sea level). The growth status Rhodiola sachalinensis showed wide range of variation in there areas. Plant height showed from 8.1cm to 15.8cm, number of branch showed from 3.1 eachs to 4.6 eachs and rate of withering showed from 76％ to 94％, respectively. It was increased rapidly at the early August caused by summer depression. Flowering period of Rhodiola sachalinensis was shown at around middle and late June, total duration of flowering showed from 12 to 13 days and flower colors were various as brown, dark purple, yellow green and brown red color.

• Molecules and Cells
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• v.41 no.5
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• pp.413-422
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• 2018

Soybean transgenic plants with ectopically expressed AtABF3 were produced by Agrobacterium-mediated transformation and investigated the effects of AtABF3 expression on drought and salt tolerance. Stable Agrobacterium-mediated soybean transformation was carried based on the half-seed method (Paz et al. 2006). The integration of the transgene was confirmed from the genomic DNA of transformed soybean plants using PCR and the copy number of transgene was determined by Southern blotting using leaf samples from $T_2$ seedlings. In addition to genomic integration, the expression of the transgenes was analyzed by RT-PCR and most of the transgenic lines expressed the transgenes introduced. The chosen two transgenic lines (line #2 and #9) for further experiment showed the substantial drought stress tolerance by surviving even at the end of the 20-day of drought treatment. And the positive relationship between the levels of AtABF3 gene expression and drought-tolerance was confirmed by qRT-PCR and drought tolerance test. The stronger drought tolerance of transgenic lines seemed to be resulted from physiological changes. Transgenic lines #2 and #9 showed ion leakage at a significantly lower level (P < 0.01) than ${\underline{n}}on-{\underline{t}}ransgenic$ (NT) control. In addition, the chlorophyll contents of the leaves of transgenic lines were significantly higher (P < 0.01). The results indicated that their enhanced drought tolerance was due to the prevention of cell membrane damage and maintenance of chlorophyll content. Water loss by transpiration also slowly proceeded in transgenic plants. In microscopic observation, higher stomata closure was confirmed in transgenic lines. Especially, line #9 had 56% of completely closed stomata whereas only 16% were completely open. In subsequent salt tolerance test, the apparently enhanced salt tolerance of transgenic lines was measured in ion leakage rate and chlorophyll contents. Finally, the agronomic characteristics of ectopically expressed AtABF3 transgenic plants ($T_2$) compared to NT plants under regular watering (every 4 days) or low rate of watering condition (every 10 days) was investigated. When watered regularly, the plant height of drought-tolerant line (#9) was shorter than NT plants. However, under the drought condition, total seed weight of line #9 was significantly higher than in NT plants (P < 0.01). Moreover, the pods of NT plants showed severe withering, and most of the pods failed to set normal seeds. All the evidences in the study clearly suggested that overexpression of the AtABF3 gene conferred drought and salt tolerance in major crop soybean, especially under the growth condition of low watering.

• Korean Journal of Medicinal Crop Science
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• v.15 no.6
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• pp.429-433
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• 2007

Shoot weight of Orostachys japonicus should determine its profitability. The study was carried out to measure the effect of nitrogen (N) fertilization level (0, 5, 10, 20kg/10a) on its growth, morphological characters, and flowering. Night-break treatment of 2 hours at midnight were done since Aug. 25 when afterward samples were taken every 4 weeks to Nov. 16. Growth, morphological and flowering related characters were measured from each sample. Plant height, inflorescence length, number of leaves including bracts and stem diameter were decreased with increased N levels. Leaf and bract, floret, shoot and total dry weights as well as withering rate showed similar response to the above morphological characters. Florets were less formed with increased N levels but were not flowered due to the night-break treatment, meaning that N fertilization had little effect on its growth and anthesis of the florets.

• Strategy21
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• s.44
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• pp.5-27
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• 2018

The purpose of this paper is to look at USN's efforts to rebuild its combat power in the face of a reemergence of great powers competition, and to propose some recommendations for the ROKN. In addition to the plan to augment its fleet towards a 355-ships capacity, the USN is pursuing to improve exponentially combat lethality(quality) of its existing fleet by means of innovative science and technology. In other words, the USN is putting its utmost efforts to improve readiness of current forces, to modernize maintenance facilities such as naval shipyards, and simultaneously to invest in innovative weapons system R&D for the future. After all, the USN seems to pursue innovations in advanced military Science & Technology as the best way to ensure continued supremacy in the coming strategic competition between great powers. However, it is to be seen whether the USN can smoothly continue these efforts to rebuild combat strength vis-a-vis its new competition peers, namely China and Russian navy, due to the stringent fiscal constraints, originating, among others, from the 2011 Budget Control Act effective yet. Then, it seems to be China's unilateral and assertive behaviors to expand its maritime jurisdiction in the South China Sea that drives the USN's rebuild-up efforts of the future. Now, some changes began to be perceived in the basic framework of the hitherto regional maritime security, in the name of declining sea control of the USN as well as withering maritime order based on international law and norms. However, the ROK-US alliance system is the most excellent security mechanism upon which the ROK, as a trading power, depends for its survival and prosperity. In addition, as denuclearization of North Korea seems to take significant time and efforts to accomplish in the years to come, nuclear umbrella and extended deterrence by the US is still noting but indispensible for the security of the ROK. In this connection, the naval cooperation between ROKN and USN should be seen and strengthened as the most important deterrents to North Korean nuclear and missile threats, as well as to potential maritime provocation by neighboring countries. Based on these observations, this paper argues that the ROK Navy should try to expand its own deterrent capability by pursuing selective technological innovation in order to prevent this country's destiny from being dictated by other powers. In doing so, however, it may be too risky for the ROK to pursue the emerging, disruptive innovative technologies such as rail gun, hypersonic weapon... etc., due to enormous budget, time, and very thin chance of success. This paper recommends, therefore, to carefully select and extensively invest on the most cost-effective technological innovations, suitable in the operational environments of the ROK. In particular, this paper stresses the following six areas as most potential naval innovations for the ROK Navy: long range precision strike; air and missile defense at sea; ASW with various unmanned maritime system (UMS) such as USV, UUV based on advanced hydraulic acoustic sensor (Sonar) technology; network; digitalization for the use of AI and big data; and nuclear-powered attack submarines as a strategic deterrent.