We present N-body simulations of globular clusters including gravitational field of the Galaxy, in order to study effects of tidal field systematically on the shape of outer parts of globular clusters using NBODY6. The Galaxy is assumed to be composed of central bulge and outer halo. We mvestigate the cluster of multi-mass models with a power-law initial mass function (IMF) starting with different initial masses, initial number of particles, different slopes of the IMF and different orbits of the cluster. We have examined the general evolution of the clusters, the shape of outer parts of the clusters, density profiles and the direction of tidal tails. The density profiles appear to become somewhat shallower just outside the tidal boundary consistent with some observed data. The position angle of the tidal tall depends on the location in the Galaxy as well as the direction of the motion of. clusters. We found that the clusters become more elongated at the apogalacticon than at the pengalacticon. The tidal tails may be used to trace the orbital paths of globular clusters.

Past literatures have not studied the impact of real-world events or information on the return and volatility of virtual currencies, particularly on the COVID-19 event, day-of-the-week effect, daily high-low price spreads and information flow rate. The study uses the ARMAGARCH model to capture Bitcoin’s return and conditional volatility, and explores the impact of information flow rate on conditional volatility in the Bitcoin market based on the Mixture Distribution Hypothesis (Clark, 1973). There were 3,064 samples collected during the period from 1st of January 2012 to 20th April, 2020. Empirical results show that in the Bitcoin market, a daily high-low price spread has a significant inverse relationship for daily return, and information flow rate has a significant positive relationship for condition volatility. The study supports a significant negative relationship between information asymmetry and daily return, and there is a significant positive relationship between daily trading volume and condition volatility. When Bitcoin trades on Saturday & Sunday, there is a significant reverse relationship for conditional volatility and there exists a day-of-the-week volatility effect. Under the impact of COVID-19 event, Bitcoin’s condition volatility has increased significantly, indicating the risk of price changes. Finally, the Bitcoin’s return has no impact on COVID-19 events and holidays (Saturday & Sunday).

Purpose: In the 4th industrial revolution, services that incorporate various smart technologies in the tourism sector have begun to gain popularity. Accordingly, academic discussions on smart tourism have also started to become active in various fields. Despite recent research, the definition of smart tourism is still ambiguous, and it is not easy to differentiate its scope or characteristics from traditional tourism concepts. Thus, this study aims to analyze the perception of smart tourism exposed online to identify the current point of smart tourism in Korea and present the research direction for conceptualizing smart tourism suitable for the domestic situation. Research design, data, and methodology: This study analyzes the perception of smart tourism exposed online based on 20,198 news data from portal sites over the past six years. Data on words used with smart tourism were collected from the leading portal sites Naver, Daum, and Google. Text mining techniques were applied to identify the social awareness status of smart tourism. Network analysis was used to visualize the results between words related to smart tourism, and CONCOR analysis was conducted to derive clusters formed by words having similarity. Results: As a result of keyword analysis, the frequency of words related to the development and construction of smart tourism areas was high. The analysis of the centrality of the connection between words showed that the frequency of keywords was similar, and that the words “smartphones” and “China” had relatively high connection centrality. The results of network analysis and CONCOR indicated that words were formed into eight groups including related technologies, promotion, globalization, service introduction, innovation, regional society, activation, and utilization guide. The overall results of data analysis showed that the development of smart tourism cities was a noticeable issue. Conclusions: This study is meaningful in that it clearly reflects the differences in the perception of smart tourism between online and research trends despite various efforts to develop smart tourism in Korea. In addition, this study highlights the need to understand smart tourism concepts and enhance academic discussions. It is expected that such academic discussions will contribute to improving the competitiveness of smart tourism research in Korea.

The objectives of this study were to evaluate total phenolic content (TPC) and individual phenolic compounds in leaves of perilla genetic resources, assess whether they could be used as distinguishing factor among germplasms, and evaluate their relationship with some quantitative and qualitative morphological characters. TPC and individual phenolic compounds were determined using Folin-Ciocalteu method and UPLC-PDA system, respectively. Wide variations in TPC (7.99 to 133.70 ㎎GAE/g DE), rosmarinic acid (ND to 21.05 ㎎/g DE), caffeic acid (ND to 1.17 ㎎/g DE), apigenin- 7-O-diglucuronide (ND to 2.21 ㎎ luteolin equivalent (㎎LUE)/g DE), scutellarein-7-O-glucuronide (ND to 5.25 ㎎ LUE/g DE), and apigenin-7-O-glucuronide (ND to 2.81 ㎎ LUE/g DE) were observed. Intensities of green pigment at abaxial and adaxial leaf surfaces were positively correlated with phenolic compounds whereas leaf length and width had negative correlation. Purple pigmented accessions were shorter in leaf length and width but exhibited higher amount of phenolic compounds compared to green pigmented accessions in most cases. Leaf shape was not related with content of phenolic compounds, color of leaves, and length/width of leaves. TPC and individual phenolic compounds along with morphological characters could be useful distinguishing factors for perilla genetic resources.

Cryopreservation is one of the ideal and suitable methods for long-term storage of plant germplasm. The plant contaminated with diseases and pathogens are decreased the multiplication rate, survival rate and high quality of plants after cryopreservation. The aim of this work was to improve a micropropagation method for lily in Korea, which is indigenous plant. In the last process of rinsing scales after surface-sterilization, we tried to control the diseases and pathogens lived within the tissue by rinsing in 0.03% sodium hypochlorite (NaClO) instead of sterile distilled water. Bulb scales of Lilium were cultured in vitro on MS medium supplemented with Plant Preservative Mixture (PPM). The results showed that L. tsingtauense accessions were observed ranged from 53.9 to 100% with a mean value of 76.8% and L. hansonii accessions were checked from 84.5 to 85.5% with a mean of 85% survival rate. The newly small bulb formed from bulb-scales was transferred to MS medium. We checked the presence of microorganisms and survival rate after 3 weeks in culture after examination of bacterial incidences. The results indicated that the non-contamination rate were shown ranged from 75.0 to 94.1% with mean value of 83.2% in L. tsingtauense species, and that L. hansonii were observed 85.1 to 91.7% with mean value of 88.4%. This study will provide a valuable basis for establishment of effective axenic cultures for in vitro micropropagation of Korean native lily species.

본 연구는 참당귀 재배 시에 발생하는 추대 참당귀를 부산물로 활용가능성이 있는지 평가하기 위해 수행하였다. 추대 참당귀의 지상부와 지하부의 총 무게는 수확기 비추대 참당귀의 지하부 무게 대비 약 98.5%로 높게 나타났다. 또한 추대 당귀의 decursin과 decursinol angelate의 총 함량은 주 생산품인 참당귀 신(身)의 지표성분 총 함량인 4.24%와 대비해 부위별로 0.64%~2.39%로 나타났으며, 이는 추출물로 이용 시 생산품 대비 15~56%에 해당하는 것으로 나타났다. 또한, 항상화 활성의 경우 추대 참당귀는 전반적으로 비추대 참당귀에 비해 우수한 것으로 나타났다. 추대 참당귀의 생산량, 지표성분 함량 그리고 항산화 활성 결과를 고려해 봤을 때, 추대 참당귀의 부산물은 사료 첨가제 및 화장품 용도의 추출물로 이용 가능성이 높은 것으로 생각된다.

Angelica gigas Nakai (AGN) is a traditional medicinal herb especially in Korea. It contains pyranocoumarins, which are major active components including decursin (D) and decursinol angelate (DA). This study was carried out to determine the change in active component content and antioxidant activity depending on the root diameter of AGN. Several processing steps are involved to use AGN roots as medicine. The dried AGN roots are divided into body (B), thick root (TkR), medium root (MR) and thin root (TnR) according to their diameter before cutting into medicine. The recovery rates of each root parts per 100 ㎏ were measured as 32.3±2.5, 9.0±1.0, 39.3±2.1 and 15.0±1.0%, respectively and the mean diameters were measured as 51.95±4.55, 7.05±0.89, 2.88±0.49 and 1.57±0.32 ㎜. Two index components, D and DA, were analyzed. The change of both D and DA content showed a similar tendency. Both D and DA content were increased as the root diameter decreased (higher in TnR). In addition, antioxidant activity was higher in B and TnR, and lower in TkR and MR than control. This study showed that the thinner the root diameter, the higher the D and DA content in AGN roots and that TnR has excellent antioxidant activity compared to other root parts, suggesting that the thinner root part of AGN could be used as a potential material.

This study describes the successful establishment of a cryopreservation protocol for Citrus limon cultivars: ‘Frost Eureka limon’ and ‘Cook Eureka limon’, using a droplet-vitrification method. The shoot tips that were excised from in vitro grown seedlings of the two cultivars were preserved in liquid nitrogen (LN) and successfully regenerated into whole plants. Excised shoot tips were pre-cultured for 1 or 2 days in 0.3 M and 0.5 M sucrose solutions at 25℃ and incubated in a loading solution (LS) composed of 17.5% glycerol + 17.5% sucrose in Murashige and Skoog (MS) medium for 40 min at 25℃. Prior to direct immersion in LN for 1 h, the shoot tips were dehydrated with plant vitrification solution 2 (PVS2) at 0℃ or PVS3 at 25℃. The frozen shoot tips were re-warmed and unloaded with 1.2 M sucrose in ½ MS for 30 min at 25℃. Shoot tips were post-cultured overnight on survival medium and then micrografted onto ‘trifoliate orange’ (Poncirus trifoliate (L.) Raf. seedling rootstocks for recovery and to produce whole plants. The highest regrowth rates were 53.5% and 50.3% for cryopreserved shoot tips of ‘Frost Eureka limon’ and ‘Cook Eureka limon’, respectively, when pre-cultured in 0.3 M and 0.5 M sucrose concentrations in a sequencing manner, with LS and treated with PVS2 for 60 min at 0℃. We also investigated whether the ammonium ion concentration on post-culture medium affected the viability of the cryopreserved Citrus shoot tips. The viability of cooled samples, following culturing on woody plant media (WPM) containing ¼ ammonium nitrate overnight before micrografting, was the highest (70.3%) in ‘Frost Eureka limon’. The study described here is a cost-effective and safe method to conserve Citrus fruit cultivars, for the improvement and large-scale multiplication of fruit plants and for breeding disease resistance.

This study describes an efficient and widely applicable droplet-vitrification following cryopreservation for shoot tips of Chrysanthemum morifolium (Ramat.) cvs. ‘Borami’ and ‘Yes morning’. The shoot tips of Chrysanthemum were precultured in Murashige and Skoog (MS) liquid medium supplemented with sucrose (0.3-0.7 M). Precultured explants were treated with loading solution (LS, C6) containing glycerol 20% and sucrose 20% for 30 min and exposed to dehydration solution (B5) containing 40% of glycerol and 40% of sucrose for 60 min at 25℃, and then transferred onto droplets containing 2.5 ㎕ PVS3 on sterilized aluminum foils (4 ㎝ × 0.5 ㎝) prior to direct immersion in liquid nitrogen (LN) for 1 h. The highest regeneration rate (%) was obtained when shoot tips were precultured with treatment-2 (exposing of shoot tips to MS + 0.3M sucrose for 30 h and then treated with MS+0.5 M sucrose for 16 h) at 25℃ in both the cultivars. The viability of cooled samples, followed by culturing on NH4NO3-free MS medium for first 5 days was increased to two-fold (80.7%) regrowth rate over those cultured on normal MS medium or MS medium containing plant growth regulators. This result shows droplet-vitrification would be a promising method for cryobanking chrysanthemum germplasm.

본 연구는 코끼리 흑마늘의 분말화를 위해 추출액과 말토덱스트린을 비율 별로 첨가한 후 분말을 제조하였으며, 제조 및 저장 조건 별로 품질 특성을 비교 분석하는데 목적을 두었다. 분말의 용해도는 90.87-96.93%으로 5:5 처리구에서 가장 높은 값을 보였으며 색깔의 경우 말토덱스트린 함량이 증가할수록 명도는 감소하였으나 적색도와 황색도는 증가하였다. 입도는 7:3 처리구를 제외하고 말토덱스트린 함량에 비례하여 증가하는 추세를 보였으며, 분산성은 0.54-0.63 범위에서 나타났다. 포화 염용액으로 다른 상대습도를 조성하여 25, 35℃에서 분말을 각각 저장했을 때 평형 수분함량은 4:6에서 가장 낮게 나타났다. 그리고 단분자층 수분함량을 산출하기 위해 GAB 식과 BET 식을 이용하였으며 모든 조건에서 0.943-0.997로 높은 R2값을 보였다. 여러 처리구 중 4:6 처리구가 단분자층 수분함량이 가장 낮았으며 다른 처리구들은 온도나 적용 식에 따라 다른 추세를 보였다. 또한 등온 흡습 모델의 적합성을 확인하기 위해 Caurie, Halsey, Kuhn, Oswin, Mizrahi 식을 사용하였는데, 그 중 Halsey, Kuhn 식이 높은 R2 값과 낮은 편차를 보여 적합성을 나타내었다.

Background : Angelica gigas Nakai (AGN) is a perennial plant found in East Asian countries and an crucial medicinal herb especially in Korea. It contains several chemicals like pyranocoumarins, which are major active components including decursin (D) and decursinol angelate (DA), essential oils and polyacetylenes. This study was carried out to determine the change in active components depending on the root diameter of AGN. Methods and Results : Several processing steps are involved to use AGN roots as medicine. The dried AGN roots are divided into body (B), thick root (TkR), medium root (MR) and thin root (TnR) according to their diameter before cutting into medicine. Among them, B and TkR are mainly used as medicine. The mean diameter of dried each root part (B, TkR, MR, TnR) were measured as 51.95, 7.05, 2.88, and 1.57 ㎜, respectively. The water content of each root part was slightly reduced depending on the size of the diameter (higher in B). In addition, the two active components, D and DA, were analyzed by high performance liquid chromatography. The change of both D and DA content showed a similar tendency. Both D and DA content were increased as the root diameter decreased (higher in TnR). Conclusion : This study showed that the thinner the root diameter, the higher the D and DA content in AGN roots, suggesting that the thinner root parts of AGN could be used as potential materials.

Background : Atractylodes japonica koidz (AJ) is a perennial herb that belongs to Atractylodes genus. The dried rhizome of AJ is known as ‘Baek-chul’. The ‘Baek-chul’ is used as important traditional medicine in north-east Asia. It is considered to be effective for the treatment of stomach disorder, virus, diuresis, inflammation, arthritis. AJ is heavily depend on import from china and only few studies have been carried out. In this study, we develop SSR marker to build a foundation of breeding, to analyze genetic diversity and to construct core collection. Methods and Results : AJ resources was collected from each different place. To find simple sequence repeat (SSR) marker, we sequenced genomic DNA of AJ resources using Illumina HiSeq 2000 System. As a result of next generation sequencing (NGS), we obtained putative SSR loci. From these SSR primers, 553 SSR primer sets were designed successfully and confirmed polymorphism by in silico analysis. Nucleotide motifs ranged from tri- to penta-. Among these, 48 primer were tested in 4 individuals by capillary electrophoresis. Finally, selected 28 SSR marker were showed clear band and polymorphism by Electrophoresis. Conclusion : In this study, we developed 28 polymorphic SSR marker using NGS, and it could be used for analyzing genetic diversity of A. japonica. These marker would be useful for breeding of new cultivar in the future.

Background : Jujube (Zizyphus jujuba. Mill) is a broad-leaved shrub belonging to the family Seagull. Its origin is India and its height is about 5 m. The flowers are gathered in two to three in May-June, with five petals and yellowish green. Leaves are alternate, egg-shaped or long egg-shaped, with clearly visible three veins. The fruit, called jujube, is an elliptical nucleus with the seed wrapped in a solid nucleus. It is 2.5 - 3.5 ㎝ in length, green at first, ripened in brown or reddish brown in September-October. Jujube uses the bud mutation to breed and spreads through grafting. Therefore, there is little difference in phenotype between cultivars. However, because of the lack of research on jujube molecular biology, there is no standard to distinguish the variety at the DNA level. In order to overcome such difficulties and to create a research foundation of jujube, we have developed molecular markers from jujube. Methods and Results : We collected 12 jujube varieties include Bogjo and extracted DNA using CTAB method. The DNA was diluted to 10 ng/㎕ and kept at -20℃. We designed the primer sets using CLC Main Workbench based on DNA InDel regions between the varieties. PCR and electrophoresis were performed to confirm the polymorphism. We designed 26 primer sets from 23 InDel regions. Eighteen of 26 primer sets amplified the amplicon from the primer screening. Eight primer sets were selected for polymorphism assays. All primer sets showed polymorphism. The domesticated cultivars were divided into two groups and the Japanese and Chinese varieties were separated. Conclusion : The InDel markers developed in this study could be good tools to differentiate the jujube cultivars cultivated in Korea.

Background : Angelica species are representative medicinal plants and it has been used in traditional medicinal methods, especially, in the traditional Asian medicine. The Angelica species used in conventional medicine varies by country according to specific regulations, i.e. A. gigas Nakai in Korea, A. sinensis Diels in China, and A. acutiloba Kitagawa in Japan. Because of the similarity between the names among Angelica, they can be confused in the market. Methods and Results : In this study, twenty-four chloroplast insertion or deletion (cpInDel) markers were developed from chloroplast DNA of A. gigas Nakai and tested for the classification of Angelica species. Primer sets were designed from flanking sequences of the discovered InDel loci from chloroplast DNA of A. gigas Nakai using CLC Main Workbench with the following parameters : primer length = 18 - 26 bp (Opt. 23 bp); GC% = 50 - 70% (Opt. 60%); Ta = 55 - 62℃ (Opt. 58℃); product size range = 120 - 300 bp. Polymorphism and genotype analysis of 13 Angelica species were performed using the developed cpInDel markers. Conclusion : The 24 cpInDel markers developed in this study could be used for genetic diversity analysis and classification of Angelica species.

Background : The Codonopsis genus belongs to the Campanulaceae, and it is recorded that there are four species of Codonopsis genus in Korea, such as Codonopsis lanceolata, Codonopsis pilosula, Codonopsis minima, and Codonopsis ussuriensis. C. lanceolata has been proved to be safety and efficacy, and has been widely used for medicinal and edible purposes for a long time in East Asian countries including Korea, China and Japan. However, little genetic research has been done. Methods and Results : Ten species of Codonopsis plants were collected and DNA was extracted using CTAB (cetyl trimethylammonium bromide) method. The extracted DNA was diluted to 5 ng/㎕ for the PCR (polymerase chain reaction) process. C. lanceolata genome was used to develop molecular markers by searching insertion and deletion regions (InDel) in the chloroplast sequence. The developed markers were applied to 4 individuals per Codonopsis species. PCR amplification was carried out using a denaturation at 94℃ for 30 sec, annealing at 58℃ for 30 sec and extension at 72℃ for 30 sec, repeated for 35 total cycles. The PCR products were separated in a 4% agarose gell at 100 V for 40 min. Conclusion : Using the molecular markers developed in this study, genetic diversity of Codonopsis genus was tested, and at the same time, a specific molecular marker was developed to differentiate C. lanceolata from the Codonopsis plants.