• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.9
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• pp.1881-1888
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• 2011

Red tide is a natural phenomenon to bloom harmful algal, which fish and shellfish die en masse. Red tide damage with respect to sea farming has been occurred each year. Red tide damage can be minimized by means of prediction of red tide blooms. Red tide prediction using naive bayes classifier can be achieve good prediction results. The result of naive bayes method only determine red tide blooms, whereas the method can not know how increasing of red tide algae density. In this paper, we proposed the red tide blooms prediction method using fuzzy reasoning and naive bayes classifier. The proposed method can enhance the precision of red tide prediction and forecast the increasing density of red tide algae.

• Korean Journal of Food Science and Technology
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• v.7 no.1
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• pp.7-10
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• 1975

A series of experiment was undertaken to pursue the possibility of aflatoxin accumulation in stored grains which were artificially contaminated with A. flavus var. columnaris isolated from deteriorated rice in Korea. In storage of rice grain, aflatoxin formation needed relative humidity over 80%, once accumulated aflatoxin was degraded by other microbial growth maintaining 50% level and the absence of other microoganisms brought about the remarkable accumulation of aflatoxin. The formation of aflatoxin in grains was increasing in the order of soybean, peanut, corn, wheat, barley, foxtail millet, rice, polished wheat, mung bean and great millet and it appears to be affected by the size and oil content of grains.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.7
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• pp.814-820
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• 2016

In order to utilize coal ash for eelgrass beds, a pilot plant experiment was carried out. Eelgrass was transplanted to on artificial bed made of granulated coal ash. Successful settlement of eelgrass was achieved and the density of the eelgrass increased at an exponential rate through vagetative propagation after 24 months. An increase in biodiversity in and around the artificial eelgrass bed was observed after the transplant took place. From the results of this experiment, it can be concluded that granulated coal ash is a suitable material for creating eelgrass beds.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.3
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• pp.170-176
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• 2008

This study was carried out to improve density of arbuscular mycorrhizal fungi (AMF) propagule and physiochemical properties of soil by planting crops at the preplanning field for ginseng cultivation. Winter crops, such as barley and rye and summer crops, such as sudangrass and soybean were cultivated in combination to improve AMF propagation and soil aggregation at the fields. Yield of harvested crops by plating with winter or/and summer crops was $3,045kg\;10a^{-1}$ of the only rye cultivation, $2,757kg\;10a^{-1}$ of sudangrass cultivation in combination with rye growing (rye/sudangrass) and $1,628kg\;10a^{-1}$ of soybean cultivation in combination with barley growing (barley/soybean), respectively. Soil aggregation rate was improved by cultivation with barley (45.7%) and with rye/sudangrass (45.1%), respectively. The density of AMF spores in soil was increased slowly by cultivating with winter crops. In summer crops cultivation system, density of AMF spores at sudangrass cultivated field was $64.0spores\;g^{-1}$ dried soil and it was higher than that at soybean cultivated field. External hyphae length (EHL) was $1.5{\sim}2.0m\;g^{-1}$ air-dried soil at winter crops cultivated field. However, in summer crops cultivation systems, EHL was $2.6{\sim}2.9m\;g^{-1}$ airdried soil at sudangrass cultivated field and was $1.7{\sim}2.2m\;g^{-1}$ air-dried soil at soybean cultivated filed, showing these were higher than those in non-cultivated field (control). Glomalin content of soil cultivated with crops was higher than that of control soil. Especially, the highest glomalin content was shown to $1.7m\;g^{-1}$ air-dried soil in the barley/soybean cultivation systems. These results suggested that the most effective soil management to improve AMF propagule density and soil physical properties by planting crops system was cultivating sudangrass followed by barley at the preplanning fields for ginseng cultivation.

• Journal of Korean Society of Forest Science
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• v.86 no.4
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• pp.443-449
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• 1997

We examined the effect of pretreatments on seed germination, seedling growth, optimal seedling density of Phellodendron amurense. The seeds were carefully purified after collection in late Oct. from natural population at Mt. Chiri. For the evaluation of pretreatment effects, seeds were sowed in an experimental nursery after being stored in open ground($2{\sim}8^{\circ}C$) with soaking in 20% $H_2O_2$, 50-fold pon-pon solution, cold moist stratification in refrigerator($2{\sim}4^{\circ}C$) and dry storage in roam temperature($4{\sim}18^{\circ}C$), respectively, For the effect of growth density of seedlings, seedlings germinated in nursery were precisely controlled with 53, 104, 220, 380 seedlings per $m^2$. Among pretreatments for the promotion of germination rate, pon-pon treatment(68.8%) was highest, the others were higher than that in dry storage(2.3%), and these seed pretreatment methods were significantly different at 1% level. The height growth of seedlings showed the most vigor from Jun.12 to Jul. 8, and from Jul.20 to Aug. 2, and it reached to 72.8% of height growth. In case of 1-0 seedling, although seedling density per $m^2$ was increased, seedling growth was decreased. The optimal seedling density was 104 seedlings per $m^2$. The standard seedlings for plantation were above height 55cm, root collar diameter 8.1mm, and root length 21cm. These results demonstrated that seed of P. amurense requires stratification for the germination promotion.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.26 no.4
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• pp.343-355
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• 2021

Eelgrass, Zostera marina L., was widely distributed around Sinyangseopji Beach in Bangdu Bay, on the eastern coast of Jeju Island, until breakwater construction in the late 1990s resulted in its complete loss. Six experimental sites were identified for restoration of the Z. marina bed in Bangdu Bay. Using the staple method, 500 Z. marina shoots were transplanted at each site in January 2019 and 2020. The transplants, along with environmental parameters, were monitored for 10 months following transplantation. There were significant differences in underwater irradiance, water temperature, and salinity among the sites, but all were suitable for Z. marina growth. The Ulva species, an opportunistic alga, appeared in spring and accumulated during summer at all sites; however, there was no significant effect of Ulva species on the survival and growth of the eelgrass transplants. Most of the transplanted Z. marina survived, and after 3 months, the density increased by 112.5-300% due to vegetative propagation, with a rapid rate of increase observed during spring and early summer at all sites. For 1-2 months after transplanting, the Z. marina shoots showed signs of transplant shock, after which the shoot density increased at all sites, confirming that all transplants adapted well to the new environment. However, in both 2019 and 2020, during late summer to early fall, the sites experienced heavy damage from typoons (twice in 2019 and three times in 2020) that hit Bangdu Bay. The transplants at two sites located in the center of Bangdu Bay were completely destroyed, but those at three sites located to the west of the bay showed a 192-312% increase in density. Thus, we confirmed that the Bangdu Bay Z. marina bed can be restored, with the highest probability of success for Z. marina restoration on the western side of Bangdu Bay, which is protected from typhoons.

• Journal of Wetlands Research
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• v.11 no.3
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• pp.49-59
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• 2009

Seasonal changes of the growth characteristics and biomass of Scirpus fluviatilis, a aquatic emergent vascular plant, were investigated to reveal the phenology and the population dynamics and to provide the fundamental resources for the restoration counterplan of the wetland vegetation in the littoral zone of the Upo wetland, Changnyeong-gun, Gyeongsangnam-do, Korea from March 2006 to November 2006. Scirpus fluviatilis was distributed commonly in Upo, Mokpo, Sajipo, Jokjibyeol, and Topyeongcheon upstream and downstream of Upo wetland, and the density was highest in Mokpo. Distribution range for the water depth was 9~49cm, and the highest shoot density in 26~49cm, and the mean shoot density was $119/m^2$, and the mean shoot length was 122.3cm on May 28. The number of the tuber was $104.5/0.25m^2$, and the living tubers were 84.2%. The mean fresh biomass of the living tubers was 3.0g, and those of 1~4g was most as 57.9%. Germination rates of the living tubers was 43.8%, and the maximum rate was in 7~9g and more than 10g. In the pot cultivation, the shoot density of the germinated tubers and the dormant tubers were highest as 13.5 and 9.7, respectively in early August. In the field study, the shoot density had few change before typhoon damage, while the density increased abruptly in November after flooding accompanied with the typhoon 'Ewiniar'. The shoot length in the pot cultivation and in the field study were 100~116cm and 60~170cm, respectively in the growth-end. Biomass allocation rates into the stem, leaf, flower, and underground parts were 8.9%, 6.6%, 0%, and 84.5%, respectively in the pot cultivation of the germinated tubers, and those of the dormant tubers were 7.1%, 7.1%, 0%, and 85.8%, respectively. The tuber number increased to 1.4~4.1 times by the growth-end, so it is concluded that Scirpus fluviatilis is mostly propagated by the vegetative reproduction.

• Journal of Bio-Environment Control
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• v.16 no.2
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• pp.146-150
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• 2007

For autumn cutting of Sedum sarmentosum, the influences of bedsoil and cutting date were investigated. Among six kinds of bedsoils mixed upland soil, carbonized rice and sand, the mixture with upland soil and sand (1:1 and 2:1, v/v) showed excellent root and shoot growth. The mixtures with upland soil and carbonized rice were lower rooting than the mixture with upland soil and sand. In field condition, autumn cutting was conducted with $10{\times}5cm$ space using the mixture with upland soil and sand (2:1, v/v) at intervals of 10 days from September 1 to October 10. Both root and shoot growth were significantly decreased by delayed date. In cutting from early to middle September, root and shoot growth, and number of rosette before wintering were desirable for shoot production next spring. The safety date to autumn cutting before wintering was on September 20 in field condition. If autumn cutting is late than September 20, the number of scion has increased 25-30% to secure a full rosette before wintering. The results could provide the beneficial information for cutting propagation of S. sarmentosum under field condition in autumn.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.5 no.1
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• pp.27-36
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• 2000

We investigated the phytoplankton community from June to September 1997 in the waters off Kohung, Korea where red tides dominated by harmful dinoflagellates had occurred from August to September or October since 1995. We took water samples five times from 5 depths at 6 or less stations in this study period. The most dominant harmful dinoflagellate during the red tide which had outbroken on August 24, 1997 was Gyrodinium impudicum, not Cochlodinium polykrikoides. On August 21 just before the harmful red tide occurred the abundance of G. impudicum at the inner bay station, 90cells $ml^{-1}$, was higher than that at the outer bay station. However, on August 27 just after the red tide had outbroken, the abundance of G. impudicum at the inner bay station did not increase, whereas that at the outer bay increased rapidly and reached to the maximum of 30,000 cells $ml^{-1}$. Instead, diatoms such as Skeleltonema costatum, Chaetoceros pseudocurvisetus, Pseudonitzschia pungens rapidly increased at the inner bay station where fresh water from lands has reached. The high abundance of diatoms might have inhibited the growth of red tide dinoflagellates at this station. The transport of already formed red tide patches from offshore areas, aggregation of scattered cells driven by physical forces, and/or competition between diatom and dinoflagellates might be responsible for this appearance of dense red tide patches at the outer bay station.

• Reproductive and Developmental Biology
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• v.29 no.1
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• pp.19-24
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• 2005

The low density lipoprotein receptor-related protein 5 (LRP5) highly expressed in many tissues, including hepatocytes and pancreatic beta cells, can bind to apolipoprotein E. To evaluate in vivo roles of LRP5, we generated LRP5-deficient mice. LRP5 genomic DNA was isolated from TT2 embryonic stem (ES) cells. Targeting vector was constructed to disrupt an exon 18 of the mouse LRP5 gene and transfected into ES cells. Three homologous recombinants at LRP5 locus were identified from 178 G418-resistant clones. Chimeric males generated by morula aggregation technique were mated to C57BL/6 female mice. After achieving germ-line transmission, LRP5+/- females were crossed with LRP5+/- males to obtain LRP5-deficient mice. One line of mice lacking LRP5 gene was confirmed by Southern blotting. Such knock-out mice may serve as an effective animal model to study in vivo function of LRP5 gene.