• Korean Journal of Medicinal Crop Science
• /
• v.5 no.1
• /
• pp.49-55
• /
• 1997

This study was conducted to establish mass propagation system from the tissue culture using immature embryos in Eleutherococcus senticosus. Immature embryos from seeds were removed under the microscope and placed on MS, $MSB_5\;and\;B_5$ medium containing several plant growth regulators. While the calli were well formed on media containing 2 mg/l of 2, 4-D, 2 mg/l of 2, 4-D and 0.7 mg/l of TDZ, shoot regeneration was better on MS medium with combinations of high concentrations of TDZ and low concentrations of 2, 4-D. Treatment of 2, 4-D alone was better than treatment of TDZ alone in callus induction, but plant regeneration was reversed. The results of callus formation and shoot regeneration on $MSB_5\;and\;B_5$ media were similar to those of MS media. The rate of callus formation was nearly 100% when 2, 4-D was added to $B_5$, medium on concentration of 2 mg/l or 0.7 mg/l. TDZ showed very significant effect on the formation of multiple shoots.

• Economic and Environmental Geology
• /
• v.43 no.4
• /
• pp.371-379
• /
• 2010

Fresh water injection test in a fractured bedrock aquifer was applied as an efficient approach to lower saline concentrations in the saltwater-freshwater transition zone formed by seawater intrusion in a coastal area. The methodology and effectiveness of fresh water injection for hydraulically controlling seawater intrusion is overwhelmingly site dependent, and there is an urgent need to characterize the permeable fractures or unconsolidated porous formations which can allow for seawater flow and transport. Considering aquifer characteristics, injection and monitoring boreholes were optimally designed and completed to inject fresh water through sand layer and fractured bedrock, respectively. We devised and used the injection system using double packer for easy field operation and maintenance. Overall fracture distribution was systematically identified from borehole image logs, and the section of fresh water injection was decided from injection test and monitoring. With fresh water injection, the fluid electrical conductivity of the monitoring well started to be lowered by the inflow of fresh water at the specific depth. And this inflow leaded to the replacement of the fluid in the upper parts of the borehole with fresh water. Furthermore, the injection effect lasted more than several months, which means that fresh water injection may contribute to the mitigation of seawater intrusion in a coastal area.

• Journal of the East Asian Society of Dietary Life
• /
• v.12 no.1
• /
• pp.38-46
• /
• 2002

This study was carried out in order to investigate dextran formation and internal structure during fermentation of the oligosaccharide Jeung-Pyun. The dextran and sugar reducing contents of Jeung-Pyun batter and the specific volume and the internal structure of Jeung-Pyun were analyzed as a function of fermentation time. The specific volume of Jeung-Pyun peaked at the 7th hour of fermentation. The dextran content of Jeung-Pyun batters peaked at the 7~13th hour of fermentation, and Fructooligosaccharide Jeung-Pyun had the least peak value. Reducing sugar content of Jeung-Pyun batters slowly decreased as fermentation progressed. From the air pore size and distribution of Jeung-Pyun observed by SEM, the sucrose Jeung-Pyun fermented for 3~7 hours and oligosaccharide one fermented for 7 hours were judged as the best. It was concluded that dextran may be formed by fermentation of oligosaccharides as well as sucrose and dextran has a significant role on the volume expansion of Jeung-Pyun.

• Journal of Science and Technology Studies
• /
• v.1 no.2 s.2
• /
• pp.371-398
• /
• 2001

Sciences and technologies are the sources which have formed presently highly developed civilizations and cultures and have enhanced the quality of human lives. But we see the dark sides of them as well as the bright sides, and we have the consciousness of environmental crisis and destruction of lives caused by them. Thus were are criticisms against human-tropism or technology-tropism from nature-tropism or deep ecology. However, if people would continue to have the desire of enjoying the present quality of their lives, they should try to develop and improve pro-environmental technologies. In this vein, we have the necessity of making environmental decisions and solving environmental problems by information technologies. Since the second half of the last century, 'environment' is the key word because we have the consciousness of environment strongly. As we solve human problems by making decisions of actions, we must face with environmental decisions in order to solve our environmental problems. If we have the better understanding of the nature of information and the role of information technology, and the relation of information technology and decision-making, we are able to design environmental systems and implement their optimal interfaces of environmental components. For this purpose, we are obliged to combine several useful technologies including GIS, DSS, Knowledge-based system and artificial neural networks. Therefore the developments and cooperations of these fields in environmental decision making enables us to live in the better and comfortable surrounding in the near future.

• Journal of Periodontal and Implant Science
• /
• v.31 no.2
• /
• pp.401-420
• /
• 2001

A novel glucanhydrolase from a mutant of Lipomyces starkeyi(KSM 22)has been shown effective in hydrolysis of mutan, reduction of mutan formation by Streptococcus mutans and removal pre-formed sucrose-dependent adherent microbial film and Lipomyces starkeyi KSM 22 dextranase has been strongly bound to hydroxyapatitie. These in vitro properties of Lipomyces starkeyi KSM 22 dextranase are desirable for its application as a dental plaque control agent. This study was performed to determine oral hygiene benefits and safety of dextranase(Lipomyces starkeyi KSM 22 dextranase)-containing mouthwash in human experimental gingivitis. This 3-week clinical trial was placebo-controlled double-blind design evaluating 1U/ml dextranase mouthwash and 0.12% chlorhexidine mouthwash. A total 39 systemically healthy subjects, who had moderate levels of plaque and gingivitis were included. At baseline, 1, 2 and 3 weeks, subjects were scored for plaque(Silness and $L{\ddot{o}e$ plaque index and plaque severity index), gingivitis($L{\ddot{o}e$ and Silness gingival index), and at baseline and 3 weeks of experiment, subjects were scored for plaque(Turesky-Quingley-Hein's plaque index and plaque severity index), tooth stain(Area and severity index system by Lang et al). Additionally, oral mucosal examinations were performed and subjects questioned for adverse symptoms. Two weeks after pre-experiment examinations and a professional prophylaxis, the subjects provided with allocated mousewash and instructed to use 20-ml volumes for 30s twice dailywithout toothbrushing. All the groups showed significant increase in plaque accumulation since 1 week of experiment. During 3 weeks' period, the dextranase group showed the least increase in plaque accumulation of Silness and $L{\ddot{o}e$ plaque index, compared to the chlorhexidine and placebo groups, but chlorhexidine group showed the least increase inplaque accumulation of Turesky-Quingley-Hein's plaque index. As for gingival inflammation, all the groups showed significant increase during 3 weeks of experiment. The dextranase group also showed the least increase in gingival index score, compared to the chlorhexidine as well as the placebo groups. Whereas the tooth stain was increased significantly in the chlorhexidine group, compared to the baseline score and the placebo group since 3 weeks of mouthrinsing. It was significantly increased after 3 weeks in the dextranase group, still less severe than the chlorhexidine group. As for the oral side effect, the dextranase group showed less tongue accumulation, bad taste, compared to the chlorhexidine group. From these results, mouthrinsing with Lipomyces starkeyi KSM 22 dextranase was comparable to 0.12% chlorhexidine mouthwashin inhibition of plaque accumulation and gingival inflammation and local side effects were if anything less frequent and less intense than chlorhexidine, in human experimental gingivitis. All data had provided positive evidence for Lipomyces starkeyi KSM 22 dextranase as an antiplaque agent and suggested that further development of dextranase formulations for plaque control are warranted.

• Geophysics and Geophysical Exploration
• /
• v.15 no.1
• /
• pp.16-22
• /
• 2012

In this study, we setup a ground-based scatterometer using an antenna of which the center frequency is 9.5 GHz (X-band), and measured radar backscatterings from air/ice and ice/water interfaces to extract ice thickness. Both of air/ice and ice/water interfaces make strong radar backscatterings and so we can clearly identify two peaks in measured data by scatterometer. By using the distance of two peaks and refractive index of ice, we confirmed that it is possible to measure ice thickness. Field survey was performed at the downstream of Jiam River flowing into Chuncheon Lake. We measured radar backscattering from river ice along a survey path and extracted ice thickness. The ice thickness map of the downstream of Jiam River was produced by using kriging which is one of well known interpolation methods. The ice thickness was about 50 cm along the mainstream while ice was thin as 30 ~ 40 cm at a fast-flowing meander. Ice thickness was particularly thinner at some locations than that of surrounding areas even in the mainstream region of constant flow. This was because of impurities in ice or artificially formed refrozen holes after fishing. We expect that this study helps to expand utilization field of X-band SAR and airborne scatterometer system.

• Journal of Periodontal and Implant Science
• /
• v.31 no.2
• /
• pp.371-388
• /
• 2001

A novel glucanhydrolase(DXAMase) from a mutant of Lipomyces starkeyi(KSM 22) has been shown effective in hydrolysis of mutan, reduction of mutan formation by Streptococcus mutans and removal pre-formed sucrose-dependentadherent microbial film and DXAMase has been strongly bound to hydroxyapatitie. These in vitro properties of Lipomyces starkeyi DXAMase are desirable for its application as a dental plaque control agent. This study was performed to determine the adjunctive oral hygiene benefits and safety of dextranase(Lipomyces starkeyi KSM 22 DXAMase)-containing mouthwash when used alongside normal tooth-brushing. This 6-month clinical trial was placebo-controlled double-blind design evaluating 1U/ml dextranase mouthwash and 0.12% chlorhexidine mouthwash. A total 39 systemically healthy subjects, who had moderate levels of plaque and gingivitis were included. At baseline, 1, 3 and 6 months, subjects were scored for plaque accumulation(Turesky modification of Quingley-Hein's plaque index), gingivitis status($L\ddot{o}e$ and Silness gingival index), and tooth stain(Area and severity index system by Lang et al). Additionally, oral mucosal examinations were performed and subjects questioned for adverse symptoms. Two weeks after pre-experiment examinations and a professional prophylaxis, the subjects provided with allocated mousewash and instructed to use 20-ml volumes for 30s twice daily after toothbrushing. All the groups showed significant increase in plaque accumulation since 1 month of experiment. During 6 months' period, the Dextranase mouthwash group showed the least increase in plaque accumulation, compared to the Chlorhexidine mouthwash and placebo groups. As for gingival inflammation, all the groups showed significant increase during 6 months of experiment. The Experimental group(Dextranase mouthwash) also showed the least increase in gingival index score, compared to the Positive control(Chlorhexidine mouthwash)as well as the Negative control(placebo)groups. Whereas the tooth stain was increased significantly in the Positive control group, compared to the baseline score and the Negative controlgroup since 3 months of mouthrinsing. It was significantly increased after 6 months in the Experimental group, still less severe than the Positive control group. As for the oral side effect, the Experimental group showed less tongue accumulation, bad taste, compared to the Positive control group. From these results, mouthrinsing with Lipomyces starkeyi KSM 22 dextranase provided adjunctive benefits to toothbrushing, comparable to 0.12% chlorhexidine mouthwash in inhibition of plaque accumulation and gingival inflammation and local side effects were if anything less frequent and less intense than chlorhexidine, with long-term use of the mouthwash. All data had provided positive evidence for Lipomyces starkeyi KSM 22 dextranase as an antiplaque agent and suggested that further development of dextranase formulations for plaque control are warranted.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.20 no.1
• /
• pp.140-145
• /
• 2010

In this work, to theoretically analyze the nonlinear charging characteristic, a Radial Basis Function Neural Network (RBFNN) is adopted. Based on the RBFNN, an charging characteristic tendency of a Linear Type Magnetic Flux Pump (LTMFP) is analyzed. In the paper, we developed the LTMFP that generates stable and controllable charging current and also experimentally investigated its charging characteristic in the cryogenic system. From these experimental results, the charging current of the LTMFP was also found to be frequency dependent with nonlinear quality due to the nonlinear magnetic behaviour of superconducting Nb foil. On the whole, in the case of essentially cryogenic experiment, since cooling costs loomed large in the cryogenic environment, it is difficult to carry out various experiments. Consequentially, in this paper, we estimated the nonlinear characteristic of charging current as well as realized the intelligent model via the design of RBFNN based on the experimental data. In this paper, we view RBF neural networks as predominantly data driven constructs whose processing is based upon an effective usage of experimental data through a prudent process of Fuzzy C-Means clustering method. Also, the receptive fields of the proposed RBF neural network are formed by the FCM clustering.

• Ecology and Resilient Infrastructure
• /
• v.2 no.2
• /
• pp.167-176
• /
• 2015

The water quality of the Gulpo Stream flowing through Incheon, Bucheon, Seoul, and Kimpo is getting worse due to a slow flow rate and bank constructions by stream channelization as well as an inflow of pollutants from living-sewages and factory-sewages. Besides, a dry stream phenomenon caused by a lack of maintenance water upstream makes a self-purification system worse, and the water quality of the Gulpo Stream is currently at its lowest level. The accumulated sludge of the streambed is mostly formed by the deposition of particle pollutants due to the slow flow rate and an artificially straightened stream channel. This accumulated sludge adsorbs a great quantity of organic materials and heavy metals. Because of the internal contamination possibility by a re-gushing, even after the pollution source is removed, it can cause future water pollution. Without a total examination as previously recommended, it is considered difficult to accomplish practical efficiency. In conclusion, the management of periodic sediment management such as dredging would be necessary in the Gulpo Stream because sediment could be an internal pollution source of stream water under anaerobic conditions.

• Journal of the Korean Wood Science and Technology
• /
• v.40 no.1
• /
• pp.10-18
• /
• 2012

A high airtightness is required for the residential spaces constructed recently to save cooling and heating energy through improving insulation performance. Because the chances to release steam formed by human activity in building and inflow of water vapor in outdoor air to residential space are reduced, the natural humidity control performance of interior materials has become more important. In this study, hygroscopic performance of thermo-physically treated wood (Pinus koraiensis) was estimated. At various relative humidity condition, the water vapor adsorption and desorption rates of wooden materials were measured as well as equilibrium moisture content. Effects of roughness and surface microstructure as physical factors and functional groups as chemical factors on the hygroscopicity were analyzed. It is expected that the results from this study and further study of measuring moisture generation in residential spaces could contribute to install a system for evaluating the hygrothermal performance of wooden building.