• Korean Journal of Organic Agriculture
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• v.15 no.3
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• pp.319-330
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• 2007

This study analyzed physical and chemical characteristics of peat soil to use peat soil as the materials fur pot media and investigated seedling quality of horticultural plants in order to use peat soil as the raw materials fur pot media. The summary of the results is as follows; The chemical characteristics of peat soil, which is main ingredient of pot media are as follows; pH was 4.9, EC was less than $2.0ds{\cdot}m^{-1}$, which interferes the growth of the plant and organic ingredient was 33%. When looking into the germination characteristics of plants according to the mixture of pot media, red pepper showed 54.2% speed of germination and 97% germination rate in peat soil single treatment. Therefore the peatsoil was appropriate for the pot media for red pepper. In case of cucumbers, in the 50 : 50 treatment of main ingredient (peat soil) and auxiliary ingredients (vermiculite, peat moss and perlite) they showed 100% speed of germination and 100% germination rate. Therefore 50 : 50 treatment was appropriate fur the pot media for cucumbers. In case of chinese cabbage, peat soil, perlite and peat moss mixture (50 : 25 : 25) treatment showed the highest speed of germination (77.5%), while the germination rate was a little lower (92.15%) than comparative soil. However, it was appropriate for the pot media for chinese cabbage. In case of watermelon, germination was bad because of the influence of EC when the teat soil ingredient is over 80%. However, in the mixture of peat soil and vermiculite (50:50) treatment, they showed 91.6% speed of germination and 100% germination rate. Therefore it was appropriate for the pot media for watermelon. When looking into the growth of the plants according to the mixture of ingredients, peat soil and perlite (50:50) mixture showed excellent seedling quality for cucumbers, peat soil and perlite (50:50) mixture showed excellent seedling quality and it was proven to be appropriate for the pot media for cucumbers. In case of watermelon, peat soil, peat moss and perlite (80 : 10 : 10) mixture showed excellent seedling quality and it was proven to be appropriate for the pot media for watermelon.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.22 no.3
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• pp.118-134
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• 2017

The radiation observation data will be used importantly in research field such as climatology, weather, architecture, agro-livestock and marine science. The Ieodo Ocean Research Station (IORS) is regarded as an ideal observatory because its location can minimize the solar radiation reflection from the surrounding background and also the data produced here can serve as a reference data for radiation observation. This station has the potential to emerge as a significant observatory and join a global radiation observation group such as the Baseline Surface Radiation Network (BSRN), if the surrounding of observatory is improved and be equipped with the essential radiation measuring instruments (pyaranometer and pyrheliometer). IORS has observed the solar radiation using a pyranometer since November 2004 and the data from January 1, 2005 to December 31, 2015 were analyzed in this study. During the period of this study, the daily mean solar radiation observed from IORS decreased to $-3.80W/m^2/year$ due to the variation of the sensor response in addition to the natural environment. Since the yellow sand and fine dust from China are of great interest to scientists around the world, it is necessary to establish a basis of global joint response through the radiation data obtained at the Ieodo as well as at Sinan Gageocho and Ongjin Socheongcho Ocean Research Station. So it is an urgent need to improve the observatory surrounding and the accuracy of the observed data.

• Horticultural Science & Technology
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• v.34 no.3
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• pp.461-471
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• 2016

This study was conducted to establish an in vitro propagation system for sea-milkwort (Glaux maritima L.), which is an endangered coastal plant species with high horticultural value. Two phenotypes, 'Red type (RT)' and 'Pistachio type (PT)' based on the colors of stem and flower, were obtained from a personal horticulturist in 2009 and used for this study as plant materials. The stock plants showed typical morphologies in flower, capsule, and seed appearances as previously reported. Low temperature treatment at $4^{\circ}C$ for four or more weeks after in vitro sowing maximized seed germination percentage, indicating that imbibition of seed and subsequent low temperature treatment are crucial for its germination. The in vitro seedlings had phenotypic variation, falling into 'RT' and 'PT' classes like the stock plants. Although slight differences depending on genotype and medium were recognized, the fourth or fifth nodes detached from the in vitro seedlings revealed the best multiplication efficacy when estimated on the basis of total number of nodes of newly developed axillary shoots. In addition, the nodes from 'RT' and 'PT' regenerated the most shoots on medium supplemented with $0.5mg{\cdot}L^{-1}$ BA alone and $0.5mg{\cdot}L^{-1}$ BA plus $0.5mg{\cdot}L^{-1}$ IAA, respectively. The node culture-derived plantlets were well acclimatized in a culture room ex vitro and completed the pseudo-annual life cycle coincident with that in the natural salt march habitat with the current cultivation method of applying fresh water-irrigation under an inland environment. This work represents the first report of in vitro propagation of sea-milkwort. Thus, our study will contribute to exo-habitat conservation and natural habitat restoration of this endangered species in addition to development of a horticultural product.

• Horticultural Science & Technology
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• v.34 no.1
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• pp.67-76
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• 2016

This study was conducted to examine the optimal environmental condition for promoting the growth of sowthistle as affected by light quality and photoperiod in a closed-type plant production system. Seeds were sown in 240-cell plug trays and then germinated for 3 days at a 24-hour photoperiod in a closed-type plant production system with LED lights (R:B:W = 8:1:1). Seedlings were transplanted and grown under 3 types of LED (R:B:W = 8:1:1, R:W = 3:7, or R:B = 8:2) and 4 photoperiods (24/0, 16/8, 8/16, or 4/20 hours) with $230{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ light intensity at a density of $20cm{\times}20 cm$. The experimental design was a randomized complete block design. Plants were cultured for 40 days un der the condition of $21{\pm}2^{\circ}C$ and $70{\pm}10%$ relative humidity after transplanting. Plants were fed with a recycling nutrient solution (pH 7.0 and EC $2.0dS{\cdot}m^{-1}$) contained in a deep floating tank. Fresh weight and dry weight of shoot or root, leaf length, and leaf area were the greatest in the photoperiod of 24/0 (light/dark) with RW LED. The highest number of leaves occurred in the photoperiod of 16/8 (light/dark) with RB LED, while the incidence of tip burn was higher in the photoperiod of 24/0 (light/dark) compared to the other treatments. Chlorophyll value was the highest in the 16/8 (light/dark) photoperiod and there was no significant difference by light quality. Chlorophyll fluorescence was the lowest in the photoperiod of 24/0 (light/dark) compared with other treatments. Therefore, in terms of economic feasibility and productivity for Ixeris dentata Nakai cultivation in a closed-type plant production system, the results obtained suggest that plants grew the best when kept in a photoperiod of 16/8 (light/dark) and light quality of combined LED RW (3:7).

• Restorative Dentistry and Endodontics
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• v.31 no.3
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• pp.192-202
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• 2006

The purpose of this study was to examine the viability of PDL cells in rat molars by using in vivo MTT assay, which was used to compare fast cryopreservation group by liquid nitrogen $(-196^{\circ}C)\;with\;4^{\circ}C$ cold preservation group. A total of 74 Sprague-Dawley white female rats of 4 week-old with a body weight of 100 grams were used. The maxillary left and right, first and second molars were extracted as atraumatically as possible under ketamine anesthesia. Ten teeth of each group were divided as six experimental groups depending upon the preservation. Cryopreservation groups were Group 1 (5% DMSO 6% HES in F medium) Group 2 (10% DMSO in F medium), Group 3 (5% DMSO 6% HES in $Viaspan^(R)$). Group 4 (10% DMSO in $Viaspan^(R)$) which were cryopreserved for 1 week and cold preservation groups were Group 5 (F medium) , Group 6 ($Viaspan^(R)$) at $4^{\circ}C$ for 1 week. Immediate extraction group was used as a control. After preservation and thawing, the in vivo MTT assay was processed. Two way ANOVA and Duncan's Multiple Range Test was performed at the 95 % level of confidence, Another 2 teeth of each group were treated as the same manner and frozen sections $10{\mu}m$ thick for microscopic observation. The value of optical density obtained after in vivo MTT analysis was divided by the value of eosin staining for tissue volume standardization. Group 1, 2 had significantly higher optical density than Group 3 and 4 which had the lowest OD value. Group 6 had higher OD value than in Group 5 (P<0.05). Histological findings of periodontal ligament cell, after being stained with MTT solution were consistent with the in vivo MTT assay results. In this study, the groups which were frozen with DMSO as a cryoprotectant and the groups with F medium showed the best results.

• Restorative Dentistry and Endodontics
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• v.35 no.6
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• pp.453-460
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• 2010

Objectives: To evaluate the accuracy and consistency of two different apex locators at both the Apex and 0.5 marks. Materials and Methods: Twenty-six root canals was scheduled for extraction for periodontal or prosthodontic reasons. Thirteen canals were measured using Root ZX and the rest by i-ROOT. The root canal length was measured both the at 0.5 mark and the Apex mark. The file was then fixed to the toot, and the distance from the file tip to the major foramen of each canal was measured after removing the root dentin under the microscope so that the major foramen and the file tip were seen. Results: 1. When the Apex mark was used, 100% of both the Root ZX and i-ROOT groups were within 0.5 mm of the major foramen. 2. When 0.5 mark was used, 100% of the Root ZX group and 77% of the i-ROOT group were within 0.5 mm of the major foramen. 3. In terms of standard deviation and quartile value, the Apex mark was more consistent than 0.5 mark in the Root ZX group, and 0.5 mark was more consistent in the i-ROOT group, but there was no statistically significant difference when compared with t-test. 4. The root canal length difference between the Apex mark and 0.5 mark was 0.22 mm and 0.46 mm in the Root ZX and i-ROOT groups, respectively. Conclusions: In this study, the Apex mark was the more consistent mark. Therefore, it is recommended to subtract 0.5 mm, which is the average length between the apex and apical constriction, from the root canal length at the Apex mark to obtain the working length clinically.

• Journal of Korean Society of Forest Science
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• v.76 no.4
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• pp.370-375
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• 1987

This study was conducted to examine the position effect of axillary buds on shoot multiplication and rooting with 1-year-old seedlings of Quercus acutissima. Shoot multiplication was greatly affected by axillary bud position: Productivity of multiple shoots were decreased in the order of top, mid and basal explants respectively. The best shoot multiplication (mean 6.1 shoots per explant) was obtained on WPM medium containing $1.0mg/{\ell}$ BAP and $0.1mg/{\ell}$ NAA using basal explant after 4-week-culture. Rooting was also greatly influenced by position. Its percentage was increased in the order of top, mid and basal explant respectively. Root initiation was better and more rapid on 1/2MS medium than GD medium. High rooting percentage (100%) was obtained on 1/2MS medium containing $0.2mg/{\ell}$ IBA after 15 days culture. Sucrose concentrations did not effect on rooting. However root development and shoot growth were greatly affected by them. Root was developed shortly on 1-2% levels and shoot growth was getting retarded, whereas both of them did not show significant difference at 3-6% levels. Rotting was decreased on 7-8% levels gradually, but shoot and leaf condition was better than any other concentrations. Survival rate of rooted explants in pot was varied according to the position of explants. Seedlings of top part were survived up to about 50% but most of mid and basal part seedlings did not survive over 4 weeks even in high humidity condition. Seedlings in pots showed normal growth over 10 months but most of them showed the condition of premature leaf shedding.

• Journal of Korean Society of Forest Science
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• v.12 no.1
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• pp.45-54
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• 1971

Ecological studies on the effect of an accidental fire on the composition of the post-fire vegetation in relation to the productivity system were made at the burned site on Mt. Samak located at Duckduwon-Ri, Sumyun, Chun Sung-Kun, Kangwon-Do, the same plots used in the previous study carried out in 1967. The result are summarized as follows. 1. In the productivity system, the standing crop measured was as follows; Carex Lanceolata var. Nana, Miscanthus purpurscens etc. were contained in the herbs and their individual number was larger than that of the woody plants. (Table 1). In the woody plants, Quercus Acutissima was the most abundant, showing larger number of tree than Quercus dentata. The S.D.R. value of the family Poaceae was the highest among the herbs and in the test plots, it was 4 times larger in number than in the controlled plots. (Table 3, Fig. 4, 5). 2. In the unburned sities, 5 dominant species were selected and by calculating their S.D.R., it was shown that woody plants, S.D.R. is 4.43 while it is 11.52 with herbs. (Table 4, Fig. 6). 3. When making comparisons with the standing crop on the higher around, it was found that the test plots had 522.45 gm more than the controlled and 1470. 53gm more than those on lower ground. These results were considered to indicate that high temperature caused by fire resulted in the increase of germination rate of seeds as it was seen in the previous study and it further stimulate the growth of the perennial plants. (Table 6, 7) 4. In the number of species, the standing crop was increased in the order of Genus Miscanthus and Genus Carex. and in the woody plants Genus Lespedeza was increased in the standing crop. 5. It was found that in the rest plots, total summed height was greater by about 6000cm than that in the controlled plots. 6. In conclusion, the forest fire gave a great loss to tall trees and woody plants burning them together with unmatured seeds. In the succession of the 2nd year it was considered that the growth of the perennial plants had been stimulated on the barned sites.

• Journal of Korean Society of Forest Science
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• v.79 no.4
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• pp.359-366
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• 1990

This study was carried out to investigate rooting rate, plagiotrophic growth and root-promoting effect of IBA in Taxus cuspidata S, et Z. cuttings. The results obtained were summarized as follows ; 1. As the ortet ages of cuttings were increased in 5, 10, to 20 years, the rooting rates were decreased in order of 85.7%, 81.7% and 62.4%, and the number of primary roots were also decreased in 5.3, 3.7 and 2.9, respectively. 2. Rooting rate by cutting types of lateral shoot were higher than those of main shoot type, significant at the 1% level. 3. IBA(l00ppm) treatment promoted the rooting rates and the number of primary roots. 4. As the ortet ages were increased in 5, 10 to 20 years, angles of central shoot of rooted cuttings which mesured cyclophysis were decreased in order of $75.9^{\circ}$, $68.5^{\circ}$ and $59.6^{\circ}$, respectively, significant at the 1% level. 5. Average angles showed $77.0^{\circ}$ for main shoot cutting, $65.9^{\circ}$ for upper lateral shoot and $61.7^{\circ}$ for lower lateral, which was significant at 1% level, and lateral shoot cutting showed more topophysis than main shoot cutting. 6. Shoot length of rooted cuttings from main shoot cutting was longer than that from lateral shoot significant at the 1% level. 7. Relationship between some characteristics showed highly positive correlation.

• (The)Study of the Eastern Classic
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• no.48
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• pp.225-252
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• 2012

In this paper, the writer examined the procedural changes of Zhuzi(朱子)'s theory of ZhongHe(中和), and also investigated the evaluations thereof made by the later generations. In the stage of ZhongHeJiuShuo(中和舊說), Zhuzi(朱子) ignored the theory of Lidong(李?), which was traditional theory argued by DaoNam School(道南學派). He met Zhangshi(張?) of HuXiang School(湖湘學派) and followed the school's philosophy, 'XianChaShiHouHanYang(先察識後涵養)', meaning what you should do first prior to making great efforts in self-cultivation is to examine the past, when desiring to know yourself. Even though Zhuzi(朱子) had learned the method of moral cultivation from Lidong(李?), he was fascinated by such method of moral cultivation as 'XianChaShiHouHanYang(先察識後涵養)' advocated by HuXiang School(湖湘學派) through discussion with Zhangshi(張?). This tells that he only recognized the fact that there were no achievements WeiFa(未發), but only the achievements YiFa(已發). In the stage of ZhongHeXinShuo(中和新說), he realized the mistakes committed in the time of ZhongHeJiuShuo(中和舊說), and put emphasis upon the achievements in the time WeiFa(未發). Zhuzi(朱子) had explained the relationships among mind, nature, and emotional bond as by his theory, 'XinTongXingQing(心統性情)', meaning that mind controls humans' original nature. Also he followed self-cultivation of Respect, no longer believing the Huhong(胡宏)'s XianChaShiHouHanYang(先察識後涵養). Such a method of self-cultivation means that his method of moral cultivation centered on the achievements YiFa(已發), which was originated from HuXiang School(湖湘學派), had been changed into the method of moral cultivation with a focus on the achievements WeiFa(未發), which was theory argued by DaoNam School(道南學派). However, Zhuzi(朱子)'s theory of ZhongHe(中和) that had seemed perfect began to be discussed and polished again during Joseon Period through the debates between Ligu(栗谷) and Niuxi(牛溪) in the 16th century, and through the debates between Youan(尤庵) and Yuxuan(寓軒) in the 17th century, also through the HuLuoLunZheng(湖洛論爭) represented by Nantang(南塘) and Weiyan(巍巖). Since Zhuzi(朱子)'s theory of ZhongHe(中和) had some flaws, it had to put through such debates as mentioned above. Those debates were generated because imperfections were found in the theory of ZhongHe(中和) by Zhuzi(朱子).