• Korean Journal of Soil Science and Fertilizer
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• v.45 no.2
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• pp.143-148
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• 2012

Sustainable agriculture requires reliable information on the spatial distribution of the soil chemical properties for effective management of paddy fields. In order to provide adequate soil nutritional information for environmental-friendly agriculture, we investigated the soil chemical properties for 260 paddy soils sampled in Gyeongnam Province from 1999 to 2011 by four years of interval. Soil chemical properties of pH, organic matter, available phosphate and silicate, exchangeable potassium, calcium, and magnesium contents were analyzed. The pH value, organic matter, available phosphate and silicate, and exchangeable calcium and magnesium in paddy soils were significantly elevated in 2011 compared to 1999. The excessive levels of organic matter and available phosphate in paddy soils were detected in 2011. The soil available phosphate was highest in mountain foot-slope (p<0.05) and the soil organic matter was highest in diluvial terrace (p<0.05). It revealed that the soil available phosphate was the responsible factor for the differentiation of soil chemical properties by the topography in paddy soils.

• Korean Journal of Environmental Biology
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• v.33 no.3
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• pp.338-344
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• 2015

In an effort to restore the amphibians in urban freshwater system the characteristics of feeding activity of Rana rugosa living in Gyeonggi-provinces (Yangpyeong-gun and Namyangju-si) was analyzed from 2013 to 2014. The stomach contents of R. rugosa was analyzed non-invasively and compared to organisms captured by sweeping and trapping in their habitat. As a result, Hymenoptera and Cleoptera were primarily preyed by R. rugosa. Particularly, the proportion of Formicidae was more than 98% among the preyed Hymenoptera. Trapped insects in the habitat of R. rugosa's in Namyangju were Hymenoptera (58%, Formicidae 99%), Collembola (17%), Orthoptera (10%) and Diptera (9%) in order in order. In Yangpyeong, trapped insects were Collembola (49%), Orthoptera (14%), Arachnida (9%), Diptera (9%), Cleoptera (7%) and Hymenoptera (3%). Even though Hemiptera and Diptera species are abundant in the streamside zones, R. rugosa could easily hunt Formicidae or Coleoptera on rocks or grassland at streamside. R. rugosa consume small sized ground-insects that are easily found rather than searching for the specific prey. Prey resource of urban stream may be not a limiting factor of R. rugosa inhabitation.

• Journal of the Korean GEO-environmental Society
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• v.14 no.8
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• pp.11-21
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• 2013

In-situ test to find the change of $Fe^{2+}$ and $Mn^{2+}$ concentrations and ion contents in groundwater was conducted during two pumping tests at the riverbank filtration site, where is the riverine area of the Nakdong River in Changnyeong-Gun. Groundwater was sampled at one pumping well and 10 monitoring wells during a 5 steps drawdown pumping test with the rates from $500m^3/day$ to $900m^3/day$ and a constant pumping test with $800m^3/day$. The change in ion concentration of groundwater was more remarkable during a step drawdown pumping test than a constant pumping test. Especially, the decrease in $Fe^{2+}$ and $Mn^{2+}$ concentrations was distinct in a step drawdown pumping test and it happens predominantly along the direction that the radius of pumping influence was small due to a good aquifer connectivity to a pumping position. The precipitation and the oxidation of iron and manganese were caused by an air inflow and a disturbance in groundwater flow due to an abrupt change in pumping rate. The pumping rate and spatial distribution of an aquifer around a pumping well need to be considered as an important factor for the development of in-situ iron and manganese treatment technology.

• Journal of Applied Biological Chemistry
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• v.55 no.3
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• pp.185-189
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• 2012

This study was conducted to investigate the effect of different steam condition and dehydration condition on physicochemical characteristics of Olbyeossal made from Waxy rice. All samples were steamed at $95-100^{\circ}C$ for 60 min or at $121^{\circ}C$ for 20 min and then were dehydrated using hot air 45, 60, $80^{\circ}C$ and sun-dried to achieve moisture contents 13-15%. Initial pasting temperature of Olbyeossal was the lower than that of nontreatment sample by parboiling. The combination in steaming $95-100^{\circ}C$ and hot drying at $45-60^{\circ}C$ was showed appropriate pasting properties compared with other condition. The hardness of Olbyeossal was significantly affected by steaming and dehydration condition. The hardness of Olbyeossal showed the higher value for steaming at $121^{\circ}C$ than $95-100^{\circ}C$. The water binding capacity (WBC) and swelling power (SP) were higher steaming at $121^{\circ}C$ than $95-100^{\circ}C$. No significant differences on WBC and SP of Olbyeossal by dehydration condition were observed. As the sensory evaluation results, the combination in steaming at $121^{\circ}C$ and hot-air drying at 45 or $80^{\circ}C$ led to increase preference for appearance, color, taste and overall acceptability. These results indicate that steaming and dehydration condition were affecting factor on physicochemical characteristics of Olbyeossal.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.9
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• pp.1256-1266
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• 2009

Effects of particle size and physical effective fibre (peNDF) of rice straw in diets on chewing activities, feed intake, flow, site and extent of digestion and rumen fermentation in goats were investigated. A 4${\times}$4 Latin square design was employed using 4 mature Liuyang black goats fitted with permanent ruminal, duodenal, and terminal ileal fistulae. During each of the 4 periods, goats were offered 1 of 4 diets that were similar in nutritional content but varied in particle sizes and peNDF through alteration of the theoretical cut length of rice straw (10, 20, 40, and 80 mm, respectively). Dietary peNDF contents were determined using a sieve for particle separation above 8 mm, and were 17.4, 20.9, 22.5 and 25.4%, respectively. Results showed that increasing the particle size and peNDF significantly (p<0.05) increased the time spent on rumination and chewing activities, duodenal starch digestibility and ruminal pH, and decreased ruminal starch digestibility and $NH_{3}$-N concentration. Intake and total tract digestibility of nutrients (i.e. dry matter, organic matter, and starch) and ruminal fermentation were not affected by the dietary particle size and peNDF. Increased particle size and peNDF did not affect ruminal fibre digestibility, but had a great impact on the intestinal and total tract fibre digestibility. The study suggested that rice straw particle size or dietary peNDF was the important influential factor for chewing activity, intestinal fibre and starch digestibility, and ruminal pH, but had minimal impact on feed intake, duodenal and ileal flow, ruminal and total tract digestibility, and ruminal fermentation.

• The Journal of Society for e-Business Studies
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• v.15 no.2
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• pp.37-53
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• 2010

As mobile communications service is growing every single year in Korea, it has pulled the interest of many researchers as wells as the executives. This research is aimed to find out factors of the mobile market that affect the utilization of mobile communication. We adopted a survey method with a pinpointed focus on how users' profile and individual experience relates with the utilization of mobile communication. For this objective, first, we primarily analyzed the mobile users' characteristics and service usage patterns. Then, we developed a conceptual model and hypotheses that are empirically examined using a covariance structure analysis, which will contribute to investigating critical success factors in mobile business. Some suggestions constitute the remaining part of this research. First, user characteristic is an important factor that affects the amount expended for mobile service. Second, user experience is another critical aspect that is highly linked with mobile payment. In alignment with our research, we propose user characteristics such as age and income, and user experience about mobile internet usage and mobile contents usage are of great significance in devising both near- and long-term mobile business strategy.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.18 no.6
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• pp.237-241
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• 2008

Hot-press sintering of AlN ceramics were carried out with $Y_2O_3$ as sintering additive at a sintering temperature $1,750{\sim}1,850^{\circ}C$. The effect of $Y_2O_3$ addition and sintering time on sintering behavior and thermal conductivity of AlN ceramics was investigated. $Y_2O_3$ added AlN showed noticeably higher denazification rate than pure AlN. The thermal conductivity of AlN specimens was promoted by the addition of $Y_2O_3$ in spite of the formation of YAG secondary phase in AlN grain boundaries and grain boundary triple junction because $Y_2O_3$ addition could reduced the oxygen contents in AlN lattice which is primary factor of thermal conductivity. Typically, the thermal conductivity of 5 wt% $Y_2O_3$ added specimen was dramatically improved by the increase of sintering time because the elimination of YAG secondary phases from the grain boundary due to the evaporation, as well as the grain-growth of AlN grains.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.3
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• pp.320-326
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• 2017

This study investigated the water extracts of fallen pear (FPWE) on tyrosinase activity and melanogenesis. In the present study, we examined the effects of FPWE on mushroom tyrosinase activity in vitro, B16F10 melanoma cell tyrosinase activity, melanin contents, and expression of melanogenic enzyme proteins such as tyrosinase. An apparent down-regulatory effect on tyrosinase activity was observed when B16F10 cells were incubated with FPWE. Results of melanin assay using B16F10 cells treated with different concentrations (50, 125, and $250{\mu}g/mL$) of FPWE showed a dose-dependent decrease in melanin content. To determine whether or not FPWE indirectly affects tyrosinase activity, we assessed mushroom tyrosinase activity upon treatment with various concentrations (125, 250, 500, and $1,000{\mu}g/mL$) of FPWE. In addition, we investigated changes in the protein level of tyrosinase by using Western blotting. Tyrosinase and microphthalmia-associated transcription factor expression levels in B16F10 melanoma cells were reduced in a dose-dependent manner by FPWE. These results suggest that FPWE reduced melanin formation by inhibition of tyrosinase activity. Therefore, we suggest that FPWE could be used an effective whitening agent for skin.

• Journal of the Korea Society of Computer and Information
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• v.20 no.3
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• pp.115-124
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• 2015

In this paper we analyse the previous (Quality of Services) and QoE(Quality of Experience) methods, and propose a high reliable network system framework and its service forwarding method that is able to provide seamless N-Screen services for proliferating disaster informations. The service satisfaction measurement, i.e., QoE, of contents consumers in N-screens services is going to be important the factor in disaster information proliferation because N-Screen services in the previous methods based on multi devices only focused on information transmission. The proposed system around these services is composed of a disaster information process framework for accepting user's service requirement, push service modules for minimizing the number of packets to be caused when carrying out the push service, and a push service controller for maximizing QoE measures. In order to provide a seamless N-Screen service on diverse screens, such as smartphone, PC, and big screen, we also have Open API(Application Programming Interface) functions. Through these results, we expect to evaluate QoS and QoE quality in the seamless N-Screen service.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.7
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• pp.4960-4968
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• 2015

In this study to improve the chloride durability of the shotcrete structure depending on types and contents of mineral admixture chloride resistance was evaluated by NT BUILD 492 of european test standards. It was also evaluated with the mechanical properties such as static strength and chloride penetration resistance. For shotcrete mixed crushed stone aggregate of the maximum size 10mm of coarse aggregates was produced. Based on 28days compression strength the variable mixed with 15% silica fume showed the highest strength in 67.55MPa. As the content of fly ash and blast furnace slag increased, the strength lowered. In the chloride penetration resistance test, OPC showed "high grade" and In the case of admixture, the penetration resistance tended to increase in all variables except the fly ash. In order to evaluate the service life, the accelerated chloride penetration test was conducted by the standards of KCL, ACI, FIB. Test results were obtained with the lowest spreading factor in a variable mixed with silica fume of 15%. At the KCI standards, It was found to have a service life of about 65 years and at the FIB standards, It was found to have a service life of 131 years. Among standards, the service life of KCI standard in all of the variables was evaluated as the lowest.