• Korean Journal of Food Science and Technology
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• v.31 no.6
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• pp.1604-1612
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• 1999

The study was carried out to investigate the quality of the wet noodle added with the powders of nopal and nopalitos from Opuntia ficus-indica. The wet noodles were prepared to the ratio of 3, 6 and 9% (w/w) of the nopal and the nopalitos based on a flour weight. The initial pasting temperature and final viscosity in an amylograph decreased as the increase of the nopal and the nopalitos powders. A cooked weight and volume decreased with the increase of the nopal and the nopalitos powders, while a cooking loss increased. From the sensory evaluation, the wet noodles included 3% nopalitos and 6% nopal powders were similarly evaluated as the noodle used whole wheat flour. Bacterial counts of wet noodle with the nopal and the nopalitos powders were always lower than those of the control. Bacterial counts of wet noodle slowly increased as the increase of the amount of nopal and the nopalitos powders during storage at $4^{\circ}C\;and\;20^{\circ}C$. The methanol extracts from the nopal showed antimicrobial activities against Escherichia coli, Escherichia coli O157 : H7, Salmonella typhimurium, and Bacillus subtilis, while the extracts from the nopalitos showed antimicrobial activity only against Escherichia coli.

• Korean Journal of Agricultural and Forest Meteorology
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• v.16 no.3
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• pp.169-180
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• 2014

Chemical weathering of forest soils can reduce atmospheric $CO_2$ concentration over geologic time scales, providing many essential elements for life. Although many studies have been conducted on the effects of elevated atmospheric $CO_2$ on forest carbon storage using open top chambers and FACE (Free air $CO_2$ enrichment) facilities since the 1990s, studies on chemical weathering of forest soils under elevated $CO_2$ are relatively rare. Here I review on how elevated atmospheric $CO_2$ can affect the chemical weathering of forest soils and suggest directions on future research. Despite the recent advances in chemical weathering of forest soils under elevated atmospheric $CO_2$, it is still not clear how the large volume of forest soils would react under the condition. Future studies on weathering of forest soils covering large areas from the tropics to the polar regions with carefully monitored pre-treatment data would provide key information on how soils, the Earth's life sustaining engine, change under climate change.

• The Journal of Engineering Geology
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• v.24 no.1
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• pp.53-67
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• 2014

Numerical modeling is commonly used to reproduce the physical phenomena of dam-break and to compile resulting flood hazard maps. The accuracy of a dam-break model depends on the physical structure that describes the volume of storage, breach formation and progress, input variables, and model parameters. Model input and parameters are subjective in that they are prescribed; hence, caution is needed when interpreting the results. This study focuses on three parameters (breach degree ${\theta}$, shape factor P, and collapse rate k) used when the dam-break model is coupled with FLO-2D (a two-dimensional flood simulation model) to estimate flood coverage and depth etc. The results show that the simulation is sensitive to the shape factor P and the collapse rate k but not to the breach degree ${\theta}$. This study will contribute to reducing flood damage from dam-break disasters in the future.

• Journal of Korea Water Resources Association
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• v.51 no.7
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• pp.555-564
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• 2018

The detention reservoir is a hydraulic structure that constructs a levee on the inland of river and sets up side weir in a section of the levee, and this facility stores a part of the flood volume in case of a flood event over a certain scale. In order to optimize the operation of detention reservoir, it is necessary to review the linkage with existing facilities in the river. In this study, the effect of water level reduction and the flow distribution was analyzed according to the location of the side weir in the detention reservoir considering the run-of-the-river gate. Two radial gates were installed in the experimental channel, and the water level in channel and the overflow of weir were measured by moving the location of the side weir upstream from the gate. As a results of experiment, it was confirmed that the water level reduction is more remarkable as the location of the side weir was closer to the gate, and the effect of flow distribution is not greatly changed. When two or more side weirs were operated, it is confirmed that the sufficient storage space was secured and the water level reduction effect with the location of the side weir is not large. In addition, the water level reduction rate according to the location of the side weir was estimated by empirical formula and it is provided as basic data that can be used in the planning of the detention reservoir.

• Applied Chemistry for Engineering
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• v.31 no.2
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• pp.153-163
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• 2020

Compared to gaeous hydrogen, liquid hydrogen has approximately 1/800 volume, 800 times higher volumetric energy density at the same pressure, and the advantage of lower explosion risk and easier transportation than gaseous hydrogen. However, hydrogen liquefaction requires larger scale facility investment than simple compression storage method. Therefore, the research on energy-saving hydrogen liquefaction processes is highly necessary. In this study, helium/neon (mole ratio 80 : 20) refrigeration cycle was investigated as the main refrigeration process for hydrogen liquefaction. Process simulation for less energy consumption were carried out using PRO/II with PROVISION V10.2 of AVEVA. For hydrogen liquefaction, energy consumption was compared in three cases: Using a helium/neon refrigerant cycle, a SMR+helium/neon refrigerant cycle, and a C3-MR+helium/neon refrigerant cycle. As a result, the total power consumptions of compressors required to liquefy 1 kg of hydrogen are 16.3, 7.03 and 6.64 kWh, respectively. Therefore, it can be deduced that energy usage is greatly reduced in the hydrogen liquefaction process when the pre-cooling is performed using the SMR process or the C3MR process, which have already been commercialized, rather than using only the helium/neon refrigeration cycle for the hydrogen liquefaction process.

• Journal of KIISE
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• v.42 no.9
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• pp.1175-1184
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• 2015

Recently, there has been an explosive increase in the volume of multimedia data that is available as a result of the development of multimedia technologies. More and more data is becoming available on a variety of web sites, and it has become increasingly cost prohibitive to have a single data server store and process multimedia files locally. Therefore, many service providers have been likely to outsource data to cloud storage to reduce costs. Such behavior raises one serious concern: how can data users be authenticated in a secure and efficient way? The most widely used password-based authentication methods suffer from numerous disadvantages in terms of security. Multi-factor authentication protocols based on a variety of communication channels, such as SMS, biometric, or hardware tokens, may improve security but inevitably reduce usability. To this end, we present a data block-based authentication scheme that is secure and guarantees usability in such a manner where users do nothing more than enter a password. In addition, the proposed scheme can be effectively used to revoke user rights. To the best of our knowledge, our scheme is the first data block-based authentication scheme for outsourced data that is proven to be secure without degradation in usability. An experiment was conducted using the Amazon EC2 cloud service, and the results show that the proposed scheme guarantees a nearly constant time for user authentication.

• Journal of the Korean GEO-environmental Society
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• v.17 no.5
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• pp.27-36
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• 2016

Low Impact Development (LID) techniques are eco-friendly storm water management process for water circulation restoration and non-point pollutant reduction. In this study, four LID techniques (Small constructed wetland, Infiltration trench box, Infiltration trench, Vegetated swale) were selected and installed as a real size at the real site. All facilities were evaluated as monitoring under the real environmental climate situation and an artificial rain with exceeding design rainfall. In various rainfall, runoff reduction efficiency and non-point pollutant removal efficiency are increased to the bigger Surface Area of LID (SA)/Catchment Area (CA) ratio and the bigger Storage Volume of LID (SV)/Catchment Area (CA) ratio. Runoff did not occur at all rainfall event (max. 17.2 mm) in infiltration trench and vegetated swale. But Small constructed wetland was more efficient at less than 10 mm, a efficiency of infiltration trench box was similar at different rainfall. Although different conditions (such as structural material of LID, rainfall flow rate, antecedent dry periods), LID techniques are good effects not only water circulation improvement but also water quality improvement.

• Journal of Yeungnam Medical Science
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• v.7 no.1
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• pp.95-103
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• 1990

Autologous transfusion, storage of one's own blood for subsequent infusion if needed, is safe and effective in a variety of scheduled operative procedures. Obstetric involvement in such programs is very limited, however, because of concern over the possibility of inducing premature labor or causing fetal distress by blood volume change or vasovagal reactions. We describe our experience with pregnant women in this program. The incidence of vagovagal reactions of autologous donation was 9.5% (2/21). After entry into this program, 17pastients received a total 37pints, which consist of 19 Autologous and 18 Homologous. Homologous transfusion was avoided in 30% of patients receiving blood. The values of the mean haematocrits before and after hpebotomy were 34.1 % and 31.8 % respectively. It was statically significant(p<0.01). We recommended that autologous blood donation by pregnant women in third trimester is safe for mothers or infants and it should be strongly encouraged for patient with placenta previa and repeated cesarean section.

• Food Science and Preservation
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• v.16 no.4
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• pp.525-533
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• 2009

To explore cattail pollen powder as a functional food ingredient, we analyzed the general components of pollen powder, tested changes in the physical properties of dough containing the powder, and investigated the process ability of powder-containing dough in bread making by adding 3%, 6%, or 9% by weight of pollen powder to wheat flour. Cattail pollen powder consisted of (all w/w) 12.7-13.2% water, 15.7-17.8% crude protein, 1.3% crude fat, 7.5-7.7% free sugar, 14.7-18.6% crude fiber, 3.4-4.9% pollen, and 49.7-55.9% soluble nitrogen-free extract (NFE). Analysis of the physical properties of dough mixed with pollen powder showed that as more pollen powder was added, the absorption rate increased, but dough stability decreased. With increasing levels of cattail pollen powder, the falling number decreased, and amylase activity increased. Fermentability was highest in dough made with 3% by weight of pollen powder, and the bread product made from such dough had the greatest volume. As more cattail pollen powder was added, the moisture activity in dough tended to decrease to a greater extent than seen in control dough, and this tendency increased with time. We found that longer storage periods were associated with greater hardness and springiness, which indicated degradation in product quality. Therefore, it is suggested that bread products containing cattail pollen powder should be consumed within 3 days of preparation. In a taste survey, bread baked with 3% (w/w) cattail pollen powder scored highest in all questionnaire items.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.221-221
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• 2015

Sustainable use of water resource and conservation of water quality are essential problems in the world. Especially, problems of water quality are serious one for human health as well as ecological system of all creatures on the earth. Recently, the importance of total effluent load as well as the concentrations of pollutant materials has been recognized not only for the conservation of water quality but also for sustainable water use in watersheds. However, the measurement or estimation of total effluent load from non-point source area such as farm lands or forests may be more difficult because both of concentration and discharge of the water are greatly changed depending on various factors especially metrological conditions such as rainfall, while the measurement from a point source area may be easy because the concentration of pollutant materials and amount of discharge water are relatively steady. Therefore, the total effluent load from a non-point source is often estimated by statistical relationships between concentration and discharge, which is called as L-Q equation. However, a lot of work and time are required to collect and analyze water samples and to get the accurate relationship or regressive equation. So, we proposed a new system for direct measurement of total effluent load of water quality from non-point source areas to solve the problem. In this system, the overflow depth at a hydraulic weir is measured with a pressure gage every hourly interval to calculate the amount of hourly discharge at first. Then, the operating time of a small electric pump to collect an amount of water which is proportional to the discharge is calculated to intake the water into a storage tank. The stored water is taken out a few days later in a case of storm event or several weeks later in a case of non-rainfall event and the concentrations of water quality such as total nitrogen and phosphorous are analyzed in a laboratory. Finally, total load of the water quality can be calculated by multiplying the concentration by the total volume of discharge. The system was installed in a small experimental forestry watershed to check the performance and know the total load of water quality from the forest. It was found that the system to collect a proportional amount of water to actual discharge operated perfectly and a total load of water quality was analyzed accurately. As the result, it was expected that the system will be very available to know the total load from a non-point source area.