• Journal of Wetlands Research
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• v.18 no.4
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• pp.378-385
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• 2016

This study aims to suggest the framework of functional assessment on lotic area based on HGM(Hydrogeomorphic) approach targeting Wetland Protected Areas which are in the type of river channel, and to set up the fundamental data as a reference wetland. A total of 10 factors in terms of hydrology, biogeochemistry, plant habitat and animal habitat was analyzed based on the original approach of HGM and each Functional Capacity Index(FCI) of those factors was calculated. As the result of the modified FCI analysis, Damyang riverine wetland which is with artificial river bank had high values in the variables of area ratio of actual vegetation in the foreland, the number of plant per area and the area ratio of Salix spp., and those values were highly reflected on the factors of Nutrient Cycling(947,668.00), Species Richness and Maintain Characteristic Plant Communites(6.39) and Maintain Spatial Structure of Habitat(11.00). The Hanbando wetland which is keeping the natural bank had higher values in the variables of structural scale and species diversity, and the those values were highly reflected on the factors of Energy Dissipation(17,805.16), Subsurface Storage of Water(0.54), Removal of Imported Elements and Compounds(103,052.73), Maintain Characteristic Detrital Biomass(2.31), Maintenance of Interspersion and Connectivity (6.50), Species Diversity of Benthic macro-invertebrates(1.60) and Species Diversity of Vertebrate & Species Number of Other Animals(2.52/ 151.50), compared to the Damyang Riverine Wetland.

• Membrane Journal
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• v.27 no.3
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• pp.263-272
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• 2017

There are several different methods to characterize membrane pore size distribution, however, it is yet difficult to accurately measure pore size range of 10-50 nm. In this work, we employed gas-liquid displacement porometer (GLDP) and liquid-liquid displacement porometer (LLDP) to characterize in-house alumina hollow fiber membrane (K-100) and commercial membranes (A-100, A-20) that exhibit pore sizes between 10-100 nm. GLDP method was more suitable for measuring the maximum pore size, and the measured mean pore size of the membranes by LLDP were better correlated with water permeability and solute rejection. It was determined that LLDP is effective for measuring pore sizes between 10-50 nm; however, the method holds intrinsic disadvantages such as low precision and high sensitivity compared to that of GLDP. Nevertheless, it is expected that the recently commercialized LLDP technique can provide useful data that other methods cannot.

• Journal of the Korea Convergence Society
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• v.7 no.6
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• pp.13-21
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• 2016

In this paper we are trying to explain the effect of temperature on polymer membrane exchange water electrolysis (PEMWE) and polymer membrane exchange fuel cell (PEMFC) simultaneously. A comprehensive studying approach is proposed and applied to a 50Watt PEM fuel cell system in the laboratory. The monitoring process is carried out through wireless LoRa node and gateway network concept. In this experiment, temperature sensor measure the temperature level of electrolyzer, fuel cell stack and $H_2$ storage tank and transmitted the measured value of data to the management control unit (MCU) through the individual node and gateway of each PEMWE and PEMFC. In MCU we can monitor the temperature and its effect on the performance of the fuel cell system and control it to keep the lower heating value to increase the efficiency of the fuel cell system. And we also proposed a mathematical model and operation algorithm for PEMWE and PEMFC. In this model, PEMWE gives higher efficiency at lower heating level where as PEMFC gives higher efficiency at higher heating value. In order to increase the performance of the fuel cell system, we are going to monitor, communicate and control the temperature and pressure of PEMWE and PEMFC by installing these systems in a building of university which is located in the southern part of Korea.

• Korean Chemical Engineering Research
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• v.52 no.6
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• pp.768-774
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• 2014

SI process is a thermochemical process producing hydrogen by decomposing water while recycling sulfur and iodine. Various technologies have been developed to improve the efficiency on Section III of SI process, where iodine is separated and recycled. EED(electro-electrodialysis) could increase the efficiency of Section III without additional chemical compounds but a substantial amount of $I_2$ from a process stream is loaded on EED. In order to reduce the load, a crystallization technology prior to EED is considered as an $I_2$ removal process. In this work, $I_2$ particle sinking behavior was modeled to secure basic data for designing an $I_2$ crystallizer applied to $I_2$-saturated $HI_x$ solutions. The composition of $HI_x$ solution was determined by thermodynamic UVa model and correlation equations and pure properties were used to evaluate the solution properties. A multiphysics computational tool was utilized to calculate particle sinking velocity changes with respect to $I_2$ particle radius and temperature. The terminal velocity of an $I_2$ particle was estimated around 0.5 m/s under considered radius (1.0 to 2.5 mm) and temperature (10 to $50^{\circ}C$) ranges and it was analyzed that the velocity is more dependent on the solution density than the solution viscosity.

• Tunnel and Underground Space
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• v.25 no.5
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• pp.462-469
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• 2015

This study carried out a topographic survey at a small-scale open-pit limestone mine in Korea (the Daesung MDI Seoggyo office) using a popular rotary-wing unmanned aerial vehicle (UAV, Drone, DJI Phantom2 Vision+). 89 sheets of aerial photos could be obtained as a result of performing an automatic flight for 30 minutes under conditions of 100m altitude and 3m/s speed. A total of 34 million cloud points with X, Y, Z-coordinates was extracted from the aerial photos after data processing for correction and matching, then an orthomosaic image and digital surface model with 5m grid spacing could be generated. A comparison of the X, Y, Z-coordinates of 5 ground control points measured by differential global positioning system and those determined by UAV photogrammetry revealed that the root mean squared errors of X, Y, Z-coordinates were around 10cm. Therefore, it is expected that the popular rotary-wing UAV photogrammetry can be effectively utilized in small-scale open-pit mines as a technology that is able to replace or supplement existing topographic surveying equipments.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.226-232
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• 2016

In the elderly, a lower muscle mass and higher body fat mass are induced by a lower level of physical activity. A negatively changed body composition with an advanced age can lead to a higher falling risk and rate of diseases. On the other hand, aerobic-type exercise positively influences the body composition and hyperlipidemia in the elderly. Therefore, this study examined the effects of aquarobic training for 12 weeks on the body composition and blood lipid levels in obese old women. The subjects (n = 31, body fat: 33.42%) completed a 12 week water based aerobic training at 12 - 13 of Borg Scale of intensity (three times per week, each session: an hour). The body composition was measured by bioelectrical impedance analysis (Inbody 770-Biospace, Seoul, Korea) and the concentrations of blood lipids (high-density lipids cholesterol (HDL), low-density lipids cholesterol (LDL), triglyceride (TG) total cholesterol (TC)) were determined at pre and post training. A paired t-test was used for data analysis with ${\alpha}=0.05$. In the results, the body composition (% body fat (p < 0.05) and waist circumference (p < 0.05)) were reduced significantly. The LDL (p < 0.05), TG (p < 0.001) and TC (p < 0.05) were reduced significantly. In conclusion, a 12 week aquarobic exercise program helps improve the body composition and concentrations of serum lipids. Therefore, aquarobic exercise can enhance lipolysis using fat as energy to induce an improvement of the body composition and induce hyperlipidemia.

• Applied Chemistry for Engineering
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• v.10 no.5
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• pp.772-777
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• 1999

$Y_2Ba_1Cu_1O_5(Y211)$ powders were prepared by pyrophoric synthesis method and by solid state reaction method using $Y_2O_3(99.9%)$, $BaCO_3(99.9%)$, and CuO(99.9%) powders in both of these processes. The phase formation and reaction kinetics of $Y_2Ba_1Cu_1O_5$ powders have been studied using X-ray diffraction analysis(XRD) of samples at various heat treatment temperatures and reaction time. The reaction characterization suggested that the phase formation rate is mainly controlled by the particle size of Y211 powders. The activation energy(${\Delta}E_a$) of Y211 phase formation in this pyrophoric synthesis method was found to be 136.42 kJ/mol compared with 149.46 kJ/mol for that of solid state reaction method. These results data showed that the pyrophoric synthesis method is kineticaly more efficient than the solid state reaction method in this $Y_2Ba_1Cu_1O_5$ system.

• Korean Journal of Community Nutrition
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• v.11 no.2
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• pp.180-190
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• 2006

The purpose of this study was to assess several indices of diet quality based on nutrient, food and food group intake of Korean adolescents based on several indices on diet quality according to residence area and body size. Using the data from the 1998 National Health and Nutrition Survey, twenty-four-hour-dietary recalls of a total of 1,110 Korean adolescents aged 13 - 19 years (male 543, female 567) were analyzed for nutrient adequacy ratio (NAR) , index of nutritional quality (INQ) , the number of foods (Dietary Variety Score, DVS) and food group consumed (Dietary Diversity Score, DDS) . In doing that, it was attempted to apply only the minimum amount of solid foods of Kant's without inclusion of liquid foods because of the very limited variety in Korean foods. Based on weight length index, 13.1% of the subjects were categorized as obese, 14.2%, overweight, 44.4%, normal and 28.3%, underweight. Only vitamin B2 intake was higher in the obese group than in the underweight group. There was no meaningful difference in energy, protein and fat intakes according to the grade of the body size. In terms of residence area, intake of fat, niacin, vitamin $B_6$ and folic acid were lower in the rural areas than in the metropolitan city. Only vitamin E intake was higher in the rural areas. Mean value of NARs (MAR) and INQs (mINQ) was also higher in the metropolitan city than in the rural areas, but there was no significant difference of these two values according to body size of the subjects. Mean DVS was 21.02 for total subjects, and has no difference between male and female and between metropolitan city and other medium-small city. But, the rural areas showed the lowest DVS of 19.05. Mean DDS in which five is a maximum score was 3.3 with no significant difference by sex and by residence area in male subjects. However, in female subjects, DDS in the rural areas was the lowest. According to body size of the subjects, there was no meaningful difference in both scores of DVS and DDS. In conclusion, most indices of nutrient intake and food and food group intake were not significantly different by body size of the subjects, while most indices were significantly different by residence areas: higher in the metropolitan city than in the rural area.

• Journal of Nutrition and Health
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• v.35 no.2
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• pp.250-262
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• 2002

This study was conducted to develop a simple flood frequency questionnaire (FFQ) based on the results of contributions of specific floods to absolute intake and between-person variance in nutrients using semi-quantitative FFQ with 93 flood items. The subjects were 554 healthy adults for development of a simple FFQ, and 37 students for a validation test of a developed simple FFQ. The contribution of specific floods to 80% absolute nutrient intake was measured by assessing their percentage in total consumption of a nutrient. To assess the contributions of floods to the between-person variance in the intake of each specific nutrient, stepwise multiple regressions were performed. The number of floods necessary to account for the respective 80% of absolute intake was 11-36, depending on the nutrient, while flower floods (5-16 floods) were required for the corresponding percentage of between-person variation for all nutrients. Important floods for between-person variance include Tangsuyuk (pork) and snacks for energy and fat, fish for protein and polyunsaturated fatty acids (PUFA) and snacks for carbohydrates. Spearman correlation coefficients between 93-itemed FFQ and 63-itemed FFQ ranged from 0.91 for vitamin A to 0.99 for fat in the population data used in developing a simple FFQ. Also, the correlation coefficients between the two FFQs were 0.82-7.92 in the population for the validation test. This study suggests that useful information on dietary intake could be obtained using a simple semi-quantitative FFQ in a large-scale dietary survey in Korea.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10b
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• pp.1639-1645
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• 1991

Because of the important role LD converters play in the production of high quality steel, various dynamic models have been attempted in the past by many researchers not only to understand the complex chemical reactions that take place in the converter process but also to assist the converter operation itself using computers. And yet no single dynamic model was found to be completely satisfactory because of the complexity involved with the process. The process indeed involves dynamic energy and mass balances at high temperatures accompanied by complex chemical reactions and transport phenomena in the molten state. In the present study, a mathematical model describing the dynamic behavior of LD converter process has been developed. The dynamic model describes the time behavior of the temperature and the concentrations of chemical species in the hot metal bath and slag. The analysis was greatly facilitated by dividing the entire process into three zones according to the physical boundaries and reaction mechanisms. These three zones were hot metal (zone 1), slag (zone 2) and emulsion (zone 3) zones. The removal rate of Si, C, Mn and P and the rate of Fe oxidation in the hot metal bath, and the change of composition in the slag were obtained as functions of time, operating conditions and kinetic parameters. The temperature behavior in the metal bath and the slag was also obtained by considering the heat transfer between the mixing and the slag zones and the heat generated from chemical reactions involving oxygen blowing. To identify the unknown parameters in the equations and simulate the dynamic model, Hooke and Jeeves parttern search and Runge-Kutta integration algorithm were used. By testing and fitting the model with the data obtained from the operation of POSCO #2 steelmaking plant, the dynamic model was able to predict the characteristics of the main components in the LD converter. It was possible to predict the optimum CO gas recovery by computer simulation