• Atmosphere
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• v.23 no.3
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• pp.283-291
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• 2013

This study investigates the changes in the atmosphere-ocean interactions over the South China Sea (SCS) by analyzing their variables in the period of 1979~2011 during the boreal summer (June-July-August). It is found that a simultaneous correlation coefficient between sea surface temperature (SST) and precipitation over SCS during summer is significantly changed before and after the late-1990s. That is, the variation of precipitation over SCS is negatively (positively) correlated with the SST variations before (after) the late-1990s. Our further correlation analysis indicates that the atmospheric forcing of the SST is dominant before the late-1990s accompanying with wind-evaporation feedback and cloud-radiation feedback. After the late-1990s, in contrast, the SST forcing of the atmosphere through the latent heat flux from the ocean to the atmosphere is dominant. It is found that the change in the relationship of atmosphere-ocean interactions over SCS are associated with the changes in the relationship with Northeast Asian summer precipitation. In particular, a simultaneous correlation coefficient between the precipitation over SCS and Northeast Asia becomes stronger during after the late-1990s than before the late-1990s. We argue that the increase of the SST forcing of the atmosphere over SCS may lead a direct relationship of precipitation variations between SCS and Northeast Asia after the late-1990s.

• Journal of the Korean Applied Science and Technology
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• v.30 no.1
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• pp.116-126
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• 2013

Glycol ethers are a group of solvents based on alkyl ethers of ethylene glycol commonly used in paints. These solvents typically have a higher boiling point, together with the favorable solvent properties of lower-molecular weight ethers and alcohols. The word "Glycol ethers" was registered as a United States trademark by Union Carbide Corp. Typically, glycol ethers are found in pharmaceuticals, sunscreens, cosmetics, inks, dyes and water based paints. On the other hand, glycol ethers are used in degreasers, cleaners, aerosol paints and adhesives. Most glycol ethers are relatively water soluble, biodegradable and only a few are considered toxic. Therefore, they are unlikely to pose an adverse risk to the environment. Recent study suggests that occupational exposure to glycol ethers is related to low motile sperm count in men, but the finding has been disputed by others. In this study, skin permeation of 3 types glycol ethers were studied in vitro using matrix such as solvent and detergent. The absorption of glycol ethers[methyl glycol ethers(MC), ethyl glycol ethers(EC) and butyl glycol ethers(BC)] has been measured in vitro through rat skin. Epidermal membranes were set up in Franz diffusion cells and their permeability to PBS measured to establish the integrity of the skin before the glycol ethers were applied to the epidermal surface. Absorption rates for each glycol ethers were determined and permeability assessment made to quantify any irreversible alterations in barrier function due to contact with the esters. Types of glycol ethers in vitro experimental results on MC> EC> BC quickly appeared in the following order: skin permeation was beneficial to the skin permeation small molecular weight, the difference in chemical structure, such as hydrophilic, because with the partition coefficient and solubility mechanisms and passive diffusion to increase the speed at which transmission is considered.

• Microbiology and Biotechnology Letters
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• v.13 no.3
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• pp.191-198
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• 1985

Seven different strains of lactic bacteria and 13 combinations of these microorganisms were tested for their acid forming capacity on a vegetable milk made from lupinseed protein concentrate(LPC). L acidophilus, L casei, S. lactis, L. mesenteroides, mixed culture of L. acidophilus and S. thermophilus, and mixed culture of S. lactis and L. mesenteroides were selected and further tested for their growth pattern and acid forming property on lupinseed milk both untreated and partly hydrolized one with carbohydrate decomposing enzymes. The enzyme hydrolized lupinseed milk had 1.5 folds of total free sugar, 8.2 folds of fructose, 3 folds glucose, 2.3 folds maltose, compared to the untreated lupinseed milk. For the untreated lupinseed milk, L. mesenteroides was appeared to be most suitable microorganism having the maximum cell concentration of 1.0 $\times$ 10$^{9}$ $m\ell$ and the final pH 4.40 with the acidity 0.46％. For the enzyme treated lupinseed milk, mixed culture of L. acidophilus and S. thermophilus showed the best performance having 1.9$\times$10$^{9}$ $m\ell$ maximum cell number and the final pH and acidity were 3.69 and 1.13％, respectively. Lactic acid fermentation altered the physical property of lupinseed milk; by fermentation the viscosity generally increased with untreated lupinseed milk, but decreased with enzyme hydrolized one. The viscosity change and sedimentation rate of fermented milk varied with the type of lactic bacteria. The results of sensory evaluation indicated that S. lactis, L. casei, mixed culture of S. lactis and L. mesenteroides, and mixed culture of L. acidophilus and S. thermophilus, grown on enzyme hydrolized lupinseed milk, could produce acceptable lactic beverage.

• Journal of Korean Society of Forest Science
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• v.87 no.3
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• pp.328-333
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• 1998

To obtain basic information for establishing a pest control strategy for insect pest management system, changes in the population densities of the black-tipped sawfly(Acantholyda posticalis posticalis Matsumura) and damage patterns in tree growth were investigated in national forests in Hoigok-ri, Kapyung-gun, Kyunggi-do, where the pest control measures were taken. The results obtained were as follows ; 1. The larval density in the soil of the forests where the insecticides were applied have been kept below economic threshold for about 7 years. The density was the highest in the middle of slopes and similar to the level of the early stage of the insect outbreak. 2. After the pest control by insecticides, reduction in tree height and diameter growth lasted for 2-3 years in trees defoliated by over 70%. 3. The diameter growth of the trees damaged by black-tipped sawfly recovered faster in upper stem than in the lower. 4. volume growth of the trees defoliated over 70% by the insect decreased for three to four years. The volume loss of trees defoliated by 70% and 90% was 19.6% and 54.0%, respectively. 5. Maintaining the rate of defoliation below 50%, which is the economic threshold, by chemical control measures had an effect of reducing the tree volume loss by $40m^2/ha$ as compared with a stand defoliated by 90%.

• Restorative Dentistry and Endodontics
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• v.35 no.4
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• pp.285-294
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• 2010

The purpose of this study was to evaluate the viability of periodontal ligament cells of rat teeth after low-temperature preservation under high pressure by means of MTT assay, WST-1 assay. 12 teeth of Sprague-Dawley white female rats of 4 week-old were used for each group. Both side of the first and second maxillary molars were extracted as atraumatically as possible under tiletamine anesthesia. The experimental groups were group 1 (Immediate extraction), group 2 (Slow freezing under pressure of 3 MPa), group 3 (Slow freezing under pressure of 2 MPa), group 4 (Slow freezing under no additional pressure), group 5 (Rapid freezing in liquid nitrogen under pressure of 2 MPa), group 6 (Rapid freezing in liquid nitrogen under no additional pressure), group 7 (low-temperature preservation at $0^{\circ}C$ under pressure of 2 MPa), group 8 (low-temperature preservation at $0^{\circ}C$ under no additional pressure), group 9 (low-temperature preservation at $-5^{\circ}C$ under pressure of 90 MPa). F-medium and 10% DMSO were used as preservation medium and cryo-protectant. For cryo-preservation groups, thawing was performed in $37^{\circ}C$ water bath, then MTT assay, WST-1 assay were processed. One way ANOVA and Tukey HSD method were performed at the 95% level of confidence. The values of optical density obtained by MTT assay and WST-1 were divided by the values of eosin staining for tissue volume standardization. In both MTT and WST-1 assay, group 7 ($0^{\circ}C$/2 MPa) showed higher viability of periodontal ligament cells than other group (2-6, 8) and this was statistically significant (p < 0.05), but showed lower viability than group 1, immediate extraction group (no statistical significance). By the results of this study, low-temperature preservation at $0^{\circ}C$ under pressure of 2 MPa suggest the possibility for long term preservation of teeth.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.32 no.3
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• pp.213-220
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• 2014

This is the study to conduct the topographical analysis using the orthophotographic data from the waypoint flight using the UAV and constructed the system required for the automatic waypoint flight using the multicopter.. The results of the waypoint photographing are as follows. First, result of the waypoint flight over the area of 9.3ha, take time photogrammetry took 40 minutes in total. The multicopter have maintained the certain flight altitude and a constant speed that the accurate photographing was conducted over the waypoint determined by the ground station. Then, the effect of the photogrammetry was checked. Second, attached a digital camera to the multicopter which is lightweight and low in cost compared to the general photogrammetric unmanned airplane and then used it to check its mobility and economy. In addition, the matching of the photo data, and production of DEM and DXF files made it possible to analyze the topography. Third, produced the high resolution orthophoto(2cm) for the inside of the river and found out that the analysis is possible for the changes in vegetation and topography around the river. Fourth, It would be used for the more in-depth research on landscape analysis such as terrain analysis and visibility analysis. This method may be widely used to analyze the various terrains in cities and rivers. It can also be used for the landscape control such as cultural remains and tourist sites as well as the control of the cultural and historical resources such as the visibility analysis for the construction of DSM.

• Journal of the Korean Recycled Construction Resources Institute
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• v.1 no.1
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• pp.8-16
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• 2013

Currently, global warming has advanced by the usage of fossil fuels such as coal and petroleum. and the atmosphere temperature in the world of 100 years(1906~2005) has been risen $0.74^{\circ}C{\pm}0.18^{\circ}C$, IPCC announced that the global warming effect of last decade was nearly doubled compared to the changes($0.07^{\circ}C{\pm}0.02^{\circ}C$/10year) in the past 100 years. Moreover, due to the global warming, heat wave, heavy snow, heavy rain, super typhoon, were caused and are increasing to happen in the world continuously causing damages and destruction of social infrastructures, where concrete structures are suffering deterioration by long-term extreme climate changes. to solve these problems, the new construction technology and codes are necessary. In this study, to solve these problems, experiments on a variety of cases considering the temperature and humidity, the main factors of climate factors, were performed, and the cases are decided by temperature and humidity. The specimens were tested in compressive strength test and split tensile test by the curing age(3,7,28 days) morever, performance based design(PBD) method was applied by using the satisfaction curve developed from the experiment date. PBD is the design method that gathers the current experimental analysis and past experimental analysis and develops the material properties required for the structure, and carries out the design of concrete mix, and it is recently studied actively worldwide. Also, it is the ultimate goal of PBD to design and perform on structures have sufficient performance during usage and to provide the problem solving for various situations, Also, it can achieve maximum effect in terms of functionality and economy.

• Journal of Distribution Research
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• v.15 no.5
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• pp.103-126
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• 2010

The development of an industry including distribution sector is influenced by not only government policy but the related firms' behaviors. Recently the large-scale retailers have had more enormous channel power than any other distributors including monopolistic makers. Now is the time for government to prepare some policies against the unfair transaction behaviors by large-scale retailers. In this paper I tried to inquire into the distribution competition policy from a political correspondent point of view related with the transition of distribution system. For the purpose of this article I compared the case of Korea with Japan. According to the results so far inquired, there are some commons and differences in the cases of the two. Some suggestions are as follows. Considering the predominant position the concept of large-scale retailers is to be extended from a single store to numerous chain stores in the political level. Government needs to examine the standard propriety for large-scale retailer; the size of selling area and amount of sales a year. When a large-scale retailer store is to be established, it need to be taken a permit or a pre-inspection. The Fair Trade Commission have to secure the neutrality from Government's strategies. And government should find out the examples of unfair transaction behavior types and prepare some proper guidelines continually. For the last time statistical data by distributors are to be fitted out and the actual investigations for estimating the effects of government policies need to be enforced.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.18 no.6
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• pp.529-537
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• 1985

The present study was carried out to investigate the effect of the partial freezing as a means of keeping freshness of mullet (Mugil cephlus). Living samples were killed and stored by icing, partial freezing at $-3^{\circ}C$ and freezing at $-30^{\circ}C$, respectively, Changes in the freshness of the mullet muscle and the phys cal properties of its meat paste product were examined during storage. The results obtained are summarized as follows: The period that k value reached to $20\%$ during storage was the longest in the frozen storage, followed by the partial frozen storage and the ice storage, which was 4 days in the mullet muscle stored by partial freezing. In the case of VBN content, it was below 20 mg/100g in the mullet muscle stored by icing and partial freezing. The oxidation of lipids in the mullet muscle was greater in the ice storage than in the partial frozen storage. The myofibrillar protein of the mullet muscle was appeared to decrease during storage, which the decreasing ratios during storage for 9 days were below $3\%$ in the frozen storage, $17\%$ in the ice storage and $10\%$ in the partial frozen storage. While, the alkali-soluble protein showed to increase and in non-protein nitrgenous compounds, sarcoplasmic protein and stroma was not a great change during storage. The decrease of gel strength, folding strength and texture of meat paste products prepared under different storage conditions was the greatest in the ice storage, the next in the partial frozen storage and such changes in the frozen storage were not so much. In gel strength of the product prepared with sample fishes stored for 10 days, the gel strength in the ice storage, partial frozen storage and frozen storage was about $30\%,\;60\%\;and\;97\%$ of the control. respectively. The expressible drip of the products increased with storage time of raw fishes, which that of the products prepared with sample fishes stored for 15 days was about 2.1 times in the ics storage, about 1.5 times in the partial frozen storage and about 1.1 times in frozen storage as much as that of the control, respectively.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.11
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• pp.758-763
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• 2014

Soil microbial fuel cells (SMFC) have gained a great attention as an eco-friendly technology that can simultaneously generate electricity and treat organic pollutants from the contaminated soil. We evaluated the effect of electrode spacing and size on the performance of SMFC treating soil contaminated with organic pollutants. Maximum power density decreased with increase in electrode distance or decrease in electrode size, likely due to higher internal resistance. The maximum voltage and power density decreased from 326 mV and $19.5mW/m^2$ with 4 cm of electrode distance to 222 mV and $5.9mW/m^2$ with 9 cm of electrode distance. In case of electrode size test, the maximum voltage and power density generated was 291 mV, $0.34mW/m^3$ when both of anode and cathode area were $64cm^2$ with 4 cm of electrode distance. The maximum voltage decreased by 19~29% when the anode area decreased to $16cm^2$ while only 3~12% of voltage decreased with cathode area decrease. The maximum power density decreased by 49~68% with decreasing anode size, and by 29~47% with decreasing cathode size. These results showed that the anode area had more significant effects than the cathode area on the power generation of SMFC which has a high internal resistance due to a coexistence of soil and wastewater in the reactor.