• Journal of Plant Biotechnology
• /
• v.29 no.2
• /
• pp.117-121
• /
• 2002

We have developed an in vitro micropropagation system via shoot formation from axillary buds using nodal segments of Corylopsis coreana. Explants from both juvenile tree (one-year-old greenhouse stock seedlings) and mature tree (ten-years-old tree in nursery) were compared with regard to propagation efficiency. Combined treatment of both BA and zeatin were effective on shoot proliferation since the best result was obtained on MS medium supplemented with 0.5∼3.0 mg/L zeatin and 0.2 mg/L BA. Generally, juvenile explants were better in both shoot proliferation and growth than mature explants. However, as the duration of in vitro culture was proceed to 6 months, explants from mature tree also produced three shoots per explant. Distinctive differences in rooting and adaptability to soil of shoots obtained from mother trees. Whereas shoots originated from juvenile explants rooted as high as 97%, those from adult explants showed 62% rooting. Similar result was also observed in soil acclimatization. The plantlets derived from juvenile plants survived 67%, while only 48% of those from adult trees survived. The results showed a possibility of the micropropagation of Corylopsis coreana through shoot formation from axillary buds. In addition, the advance of the research still remain to enhance the frequency of acclimatization of plantlets from mature trees for practical application.

• Research in Plant Disease
• /
• v.14 no.3
• /
• pp.159-164
• /
• 2008

Crown gall of rose (Rosa hybrida) was observed in greenhouse during 2003-2007. The average disease incidence was up to 38.1 % and was more severe in hydroponic culture as compared to soil culture. The typical gall symptom occurred mainly on the root, crown, or both, and resulted on poor rooting, growth retardation and yield loss. The reduction rate of rooting influenced by crown gall was 57.5% as compared to healthy plants on nursery stock. The location of gall formation in the plant influenced growth vigor resulting in symptoms such as poor shooting. Healthy plants produced 19.1 flowers/$m^2$, while diseased plants produced 9.5 flowers/$m^2$ during the same cultivation period. Moreover, the number of days to flowering was longer for the diseased plants than for healthy plants - 51.2 days and 39.8 days for first harvest, and 60.6 days and 52.1 days for the second harvest, respectively. Conclusively, infection on the basal stem caused serious loss of the number of shoot formation; yield loss of cut flower was 38.7% due to crown gall infection and delay of harvesting time about 8-10 days.

• Food Science and Biotechnology
• /
• v.16 no.4
• /
• pp.515-519
• /
• 2007

Rapid immunochromatographic assay (ICA) kits were developed using flagella-specific monoclonal antibodies (MAbs) and rabbit polyclonal antibodies for screening Listeria spp. in food. The establishment of different formats, MAb 2B1 as capture antibody and MAb 7A3 or rabbit polyclonal antibodies as detector antibody, was compared. The 2 formats of the ICA kit were shown to have specific reactions with Listeria and no cross-reactivity with any of the non-Listeria including Escherichia coli O157:H7 and Salmonella enteritidis. The detection limits of the ICA kit using the combination of gold-labeled MAb 7A3 and MAb 2B1 showed $1{\times}10^5$ and $1{\times}10^6\;CFU/0.1\;mL$ at 22 and $30^{\circ}C$, respectively. The other format of the ICA kit using the combination of gold-labeled rabbit polyclonal antibodies and MAb 2B1 showed $1{\times}10^6\;CFU/0.1\;mL$ at $22^{\circ}C$ but weak signal at 30 culture. The format utilizing MAb was more sensitive than the one using polyclonal antibodies for capture antibody. Samples contaminated with L. monocytogenes 4b culture (9-10, 5-6, and 1-2 CFU/mL) on pork and pasteurized milk were confirmed as positive results. Current data suggests that this ICA kit is a rapid, simple and effective tool to screen for Listeria spp. in food.

• The Journal of the Convergence on Culture Technology
• /
• v.8 no.5
• /
• pp.697-703
• /
• 2022

Due to the recent economic downturn caused by Covid-19 and the unstable international situation, many investors are choosing the derivatives market as a means of investment. However, the derivatives market has a greater risk than the stock market, and research on the market of market participants is insufficient. Recently, with the development of artificial intelligence, machine learning has been widely used in the derivatives market. In this paper, reinforcement learning, one of the machine learning techniques, is applied to analyze the scalping technique that trades futures in minutes. The data set consists of 21 attributes using the closing price, moving average line, and Bollinger band indicators of 1 minute and 3 minute data for 6 months by selecting 4 products among futures products traded at trading firm. In the experiment, DNN artificial neural network model and three reinforcement learning algorithms, namely, DQN (Deep Q-Network), A2C (Advantage Actor Critic), and A3C (Asynchronous A2C) were used, and they were trained and verified through learning data set and test data set. For scalping, the agent chooses one of the actions of buying and selling, and the ratio of the portfolio value according to the action result is rewarded. Experiment results show that the energy sector products such as Heating Oil and Crude Oil yield relatively high cumulative returns compared to the index sector products such as Mini Russell 2000 and Hang Seng Index.

• Korean Journal of Culture and Social Issue
• /
• v.13 no.3
• /
• pp.89-109
• /
• 2007

This study is an exploratory study on stock investment behaviors of individual investors in psychological perspective. The study is based on many behavioral finance studies which overconfidence of individual investors has an effect on irrational investment decision making and investment behaviors such as excessive trading. Accordingly, this study was to investigate the factors of self-enhancement perception on confidence of investment of individual investors and to find whether these psychological biases lead to irrational investment behaviors. The results indicated that there were sex differences in the factors of self-enhancement perception on individual investors' confidence of investment. In case of male investors, they were confident of their ability of investment but in case of female investors, they were confident of optimistic expectation of return. Also, male investors were more confident of investment than female investors. In addition, the result showed that risky investment behaviors of individual investors were influenced by psychological factors such as favorable self-evaluation, confidence of self-controllability, optimistic expectation of return and confidence of investment in part. This study suggests that further researches need to search after other variables which can mediate between psychological factors and investment behaviors of individual investors.

• Journal of Plant Biotechnology
• /
• v.50
• /
• pp.82-88
• /
• 2023

Shoot-tip culture was used to produce clonal plants of radish stock seeds. Using 6-benzyladenine (BA), the largest number of RA2 line multi-shoots were formed with an average of 14.67 shoots on 1.33 µM BA in early seedlings and 11.33 shoots on 1.78 µM BA in juvenile seedlings. The largest number of RA4 line multi-shoots were formed with an average of 11.67 shoots on 2.22 µM BA in early seedlings and 13.67 shoots on 1.33 µM BA in juvenile seedlings. There was little difference in the significance level by BA concentration in both lines. Using Thidiazuron (TDZ), the number of RA2 line multi-shoots increased with increasing TDZ concentration, forming the largest number of multi-shoots in 0.45 µM TDZ (7.0 and 3.0 multi-shoots for early and juvenile seedlings, respectively), but few multi-shoots were formed from TDZ 2.25 and 4.5 µM. RA4 line produced almost no multi-shoots in early seedlings, and 3.7 multi-shoots were produced in 0.23 and 0.45 µM TDZ in juvenile seedlings, but not at higher concentrations. Analysis of the tissue culture seedlings grown by cultivating the generated multi-shoots with Radish Foundation seeds using SSR marker revealed a weak pattern of mutation in the generated tissue culture seedlings, but there was no mutant. In addition, in terms of root roots, both RA2 and RA4 lines generally had the best rooting, number of roots, and degree of root development in 4.9 µM indol-3- butyric acid (IBA).

• Journal of The Korean Dental Society of Anesthesiology
• /
• v.14 no.1
• /
• pp.41-47
• /
• 2014

Background: Autophagy is a self-eating process that is important for balancing sources of energy at critical times in development and in response stress. Autophagy also plays a protective role in removing clearing damaged intracellular organelles and aggregated proteins as well as eliminating intracellular pathogens. The purpose of the present study was to examine the protective effect of propofol against hypoxic damage using keratinocytes. Methods: Human keratinocytes (HaCaT cells) were obtained from the American Type Culture Collection. Propofol which were made by dissolving them in DMSO were kept frozen at $-4^{\circ}C$ until use. The stock was diluted to their concentration with DMEM when needed. Prior to propofol treatment cells were grown to about 80% confluence and then exposed to propofol at different concentrations (0, 25, 50, 75, $100{\mu}M$) for 2 h pretreatment. Cell viability was measured using a quantitative colorimetric assay with thiazolyl blue tetrazolium bromide (MTT assay), and fluorescence microscopy and western blot analysis were used for evaluation of autophagy processes. Results: The viability of propofol-treated HaCaT cells was increased in a dose-dependent manner. Propofol did not show any significant toxic effect on the HaCaT cells. The autophagy inhibitor, 3-methyladenine, reduced cell viability of hypoxia-injured HaCat cells. Fluorescence microscopy and western blot analysis showed propofol induce autophagy pathway signals. Conclusions: Propofol enhanced viability of hypoxia-injured HaCaT cells and we suggest propofol has cellular protective effects by autophagy signal pathway activation.

• Management & Information Systems Review
• /
• v.17
• /
• pp.191-214
• /
• 2005

Recently, most enterprises are having a knowlege management boom. A number of books associated with the knowlege management are being published, countless public seminars are held, and many research councils have been organized studying it formally or informally as if not importing the system is like falling behind a fashion. However, there are not many cases that achieved success by constructing the system of knowledge management. Then, why the knowledge management is not so much effective despite so many voices wanting the change of management system and a lot of public lectures about it? I guess the reason is that most companies do not have concrete methodology. Seeing a result of a survey which reported that with spread of venture boom and successful examples being known widely, the outflow of precious human resources is accelerated and a large number of employees of conglomerates have already resigned or are considering separation from their positions, we can realize that are occurring a change which can be nearly called severance in an occupational view and an organization culture. The preference to a large enterprise or a public institution of labor is low today and the notion about a lifelong job is regarded as past remains. As for this, it could be said that the social atmosphere that pursued the stability of a job has been changed to the practical one that attaches importance to ability and pay. The way of thinking of employees has been changed while established organizations cannot satisfy their desire and this explains why important members of a company are flown out. The reason why superior human resources move to venture businesses is that they can do their likable work and also prove their ability as well as unconventional rewards. Although existing companies are trying to preserve important human resources through performance compensating stock option, temporary patching up of personnel management cannot retard the rushing wind of foundation and the outflow of labor. On the contrary, clumsy import of performance-based reward system not only fails to hire superior labor power but also can bring about a sense of incompatibility and conflicts among the remaining employees. Therefore, this thesis, focusing on how to choose, develop, and maintain the human resources, will suggest a future-aiming human resources management model of Korean enterprises after comparing and analyzing the actual condition of domestic companies and the trends of advanced corportaions.

• Journal of the Economic Geographical Society of Korea
• /
• v.14 no.3
• /
• pp.307-324
• /
• 2011

The culture industry is viewed as a driving industry in the 21th century. Korea has experienced the rapid growth rate of the cultural industry in terms of sale amounts for the period of 2004-2009. The purposes of this study are to analyze the spatial pattern of the cultural industry and to empirically examine the effect of municipalities' cultural industries on regional economy using SUR model. The major findings are as follows: First, cultural industries are concentrated in the capital region and several metropolitan areas. Secondly, the estimated result of SUR model shows that there is inter-relationship between cultural industry and regional economy. The effect of the cultural industry on GRDP is that the cultural industry increased 1%, GRDP increased by 0.46%. In turn, GRDP increased 1%, cultural industry increased by 0.75%. Thirdly, the elasticity of the cultural industry on GRDP is much higher than that of labor or capital stock, showing that the cultural industry has a more powerful influence on its regional economy. Fourth, the elasticity of the cultural industry on GRDP of Gun is higher than that of shi, indicating that it is rational for Gun to develop strategies to promote competitive power of the cultural Industry for regional economic growth.

• Research in Plant Disease
• /
• v.10 no.4
• /
• pp.345-348
• /
• 2004

Pink rot of Palm was occurred at Yeuju area in 2001 and 2003. Infected plants showed rotting at the leaf-stock bases and killing of the terminal bud. The first symptoms are dark brown necrotic areas on the stem. Bases of infected frond may be covered with pink spores and the spots produced oozing gum pockets. Oozing lesions occur on the stems, and leaves turn brown and droop. The causal agent were isolated from salmon-pink spores sporulating on the leaf sheaths and necrotic stem tissues. Pathogen were isolated from freshly infected tissues were identified as Gliocladium vermoseni based on mycological characteristics. Fungus were grown plenty on PDA culture. Temperature for mycelial grown was tested at 5 to $40^{\circ}C$ and optimal temperature was $25^{\circ}C$ and was not nearly grew at temperature above $35^{\circ}C$. Artificial pathogenicity were tested on 9 species of Palm family in the wound inoculation and symptoms showed similar to those observed in the field. This is the first report on pink rot of palm in Korea.