• Journal of the Korean Institute of Landscape Architecture
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• v.42 no.4
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• pp.1-9
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• 2014

This research aims to analyze changes in anion according to locations through changes in the measuring point centering on a single tree. The subject tree was the Zelkova serrata which is most widely used as a landscape tree, and the measurement was conducted for a total of 3 days with summer solstice as the basic date. In consideration of the solar altitude and the location of the Zelkova serrata, a total of 4 measurement points - $T_a$ at the opposite direction of the shadow, $T_b$ in the center of the tree $T_c$ in the center of the shadow, and $T_d$ at the end of the shadow - were established. The mean temperature of the measurement days was the highest at $T_a$ with $28.4^{\circ}C$ and was the lowest at $T_c$, in the center of the shadow with $27.9^{\circ}C$. The relative humidity was the lowest with 42.5% at $T_a$ where the temperature was the highest. The amount of insolation was the highest at $T_a$ with $1,024.6W/m^2$, followed by $T_d(701.48W/m^2$), $T_c$($215.63W/m^2$), and $T_b(227.75W/m^2)$, and the anion was the highest at $T_a$ with $654ea/cm^3$, followed by $T_d$, $T_c$, and $T_b$, with $639.4ea/cm^3$, $615.3ea/cm^3$, $612.3ea/cm^3$, respectively. The results of the correlation analysis proved that anion correlated with the temperature, the amount of insolation, and the relative humidity on the significant level. Of these, the temperature and the amount of insolation had the positive correlation with the correlation coefficients of .687 and .332, respectively, and the significance probability of .000, and .037, respectively. The relative humidity was found to have negative correlation. Its correlation coefficient and the significance probability were -.557, and .000, respectively.

• Korean Journal of Environmental Biology
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• v.35 no.3
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• pp.413-425
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• 2017

This manuscript describes the relationship between climate change and forest growth, forest species, carbon stocks, and tree mortality. 1) In the aspect of forest growth, the growth of major coniferous species, including Pinus densiflora, had a negative correlation with temperature. On the other hand, major deciduous oak species, including Quercus variabilis and Quercus mongolica, had a positive correlation with temperature. 2) When considered in the aspect of the forest species distribution, various models commonly showed a decrease in the distribution of coniferous species and an increase in oak species due to climate change in the medium to long term. 3) From the carbon stock perspective, there was a difference in the estimation according to the status of forest management. Most of Korean forests will mature to become over-matured forest after year 2030 and are estimated to produce approximately 410 million ton forest biomass until 2090 with the current cutting regulations for sustainable forest management announced by the Korean Forest Service. 4) In the forest mortality, the mortality rate of the major coniferous species showed a clear tendency to increase higher temperatures while it decreased for the oak species with no verification of statistical significance. Moreover, the mortality of the subalpine coniferous species was projected to progress rapidly. considering the overall impacts described above, there should be a management strategy for coniferous species that are relatively vulnerable to climate change. Moreover, a sustainable forest plan in the aspect of ecosystem services, carbon sequestration and storage, which is linked to global issues such as Sustainable Development Goals, ecosystem services and negative emission.

• Journal of Biomedical Engineering Research
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• v.19 no.1
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• pp.59-68
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• 1998

Digital hearing aids offer many advantages over conventional analog hearing aids. With the advent of high speed digital signal processing chips, new digital techniques have been introduced to digital hearing aids. In addition, the evaluation of new ideas in hearing aids is necessarily accompanied by intensive subject-based clinical tests which requires much time and cost. In this paper, we present an objective method to evaluate and predict the performance of hearing aid systems without the help of such subject-based tests. In the hearing impairment simulation(HIS) algorithm, a sensorineural hearing impairment medel is established from auditory test data of the impaired subject being simulated. Also, the nonlinear behavior of the loudness recruitment is defined using hearing loss functions generated from the measurements. To transform the natural input sound into the impaired one, a frequency sampling filter is designed. The filter is continuously refreshed with the level-dependent frequency response function provided by the impairment model. To assess the performance, the HIS algorithm was implemented in real-time using a floating-point DSP. Signals processed with the real-time system were presented to normal subjects and their auditory data modified by the system was measured. The sensorineural hearing impairment was simulated and tested. The threshold of hearing and the speech discrimination tests exhibited the efficiency of the system in its use for the hearing impairment simulation. Using the HIS system we evaluated three typical hearing aid algorithms.

• Horticultural Science & Technology
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• v.29 no.5
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• pp.420-432
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• 2011

Population dynamics of greenhouse whitefly, Trialeurodes vaporariorum (Westwood), were modeled and simulated to compare the temperature effects of air and tomato leaf inside greenhouse using DYMEX model simulator (pre-programed module based simulation program developed by CSIRO, Australia). The DYMEX model simulator consisted of temperature dependent development and oviposition modules. The normalized cumulative frequency distributions of the developmental period for immature and oviposition frequency rate and survival rate for adult of greenhouse whitefly were fitted to two-parameter Weibull function. Leaf temperature on reversed side of cherry tomato leafs (Lycopersicon esculentum cv. Koko) was monitored according to three tomato plant positions (top, > 1.6 m above the ground level; middle, 0.9 - 1.2 m; bottom, 0.3 - 0.5 m) using an infrared temperature gun. Air temperature was monitored at same three positions using a Hobo self-contained temperature logger. The leaf temperatures from three plant positions were described as a function of the air temperatures with 3-parameter exponential and sigmoidal models. Data sets of observed air temperature and predicted leaf temperatures were prepared, and incorporated into the DYMEX simulator to compare the effects of air and leaf temperature on population dynamics of greenhouse whitefly. The number of greenhouse whitefly immatures was counted by visual inspection in three tomato plant positions to verify the performance of DYMEX simulation in cherry tomato greenhouse where air and leaf temperatures were monitored. The egg stage of greenhouse whitefly was not counted due to its small size. A significant positive correlation between the observed and the predicted numbers of immature and adults were found when the leaf temperatures were incorporated into DYMEX simulation, but no significant correlation was observed with the air temperatures. This study demonstrated that the population dynamics of greenhouse whitefly was affected greatly by the leaf temperatures, rather than air temperatures, and thus the leaf surface temperature should be considered for management of greenhouse whitefly in cherry tomato grown in greenhouses.

• Journal of agricultural medicine and community health
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• v.35 no.1
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• pp.1-12
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• 2010

Objectives: The purpose of this study was to classify frail and non-frail elderly and to investigate health promoting behaviors and perceived health status in the elderly according to the type of residency. Methods: This was a descriptive study. Data collection was performed from June 15th, 2009 to August 2nd, 2009. The subjects were selected at D city in Korea. Data was analyzed by descriptive statistics, $x^2$-test, and ANCOVA test with SPSS/Win 15.0 program. Results: 20.8% of the elderly living at home and 49.2% of those living in institution were frail. Frailty of the elderly living in institution was severer than those living at home. Non-frail elderly according to the type of residency showed higher scores of health promotion behavior and perceived health status than frail elderly. The elderly living at home showed higher scores of health promotion behavior than those living in institution. Conclusions: In the comparison study between the elderly living at home and institution, ratio of frail elderly among the elderly living in institution is high and health promotion behaviors are deficient as well. Frail preventive program for the elderly is needed to develop and apply in consideration of these findings.

• Korean Journal of Ecology and Environment
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• v.39 no.1 s.115
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• pp.110-118
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• 2006

The Namyang Stream in Hwaong polder was planned for several water uses including recreation, where people can contact the water and consume some amount during the recreational activity. A human health risk was assessed from exposure to E. coli in the Namyang Stream, which receives partially treated wastewater from watershed. The QUAL2E model was applied to simulate stream water quality, and this model was calibrated and verified with field monitoring data. The calibration result showed a high correlation coefficient of greater than 0.9. The mean concentration of E. coli in the Namyang Stream from the QUAL2E output was in the range of 5,000 ${\sim}$ 8,000 MPN 100 mL^{-1}$, which exceeded national and international guidelines. The Beta-Poisson was used to estimate the microbial risk of pathogens ingestion and the Monte-Carlo analysis (10,000 trials) was used to estimate the risk characterization of uncertainty. The Microbial risk assessment showed that the risk ranged from 7.9 ${\times}\;10^{-6}\;to\;9.4\;{\times}10^{-6}$. Based on USEPA guidelines, the range of $10^{-6}\;to\;10^{-8}$ was considered reasonable levels of risk for communicable disease transmission from environmental exposure, and the risk above $10^{-4}$ was considered to be in the danger of infection. Therefore, water quality of the Namyang Stream might not be in the danger of infection although it exceeded national and international guidelines. However, it was in the range of communicable disease transmission, and thorough wastewater collection and treatment at the source is recommended to secure safe recreation water quality.

• Journal of Dairy Science and Biotechnology
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• v.32 no.1
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• pp.17-29
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• 2014

GRAS probiotics can be used to modulate intestinal microbiota and to alleviate various gastrointestinal disorders. In several recent studies, researchers have explored the potential expansion and usability of probiotics to reduce the risk factors associated with diseases, including obesity, hypercholesterolemia, arterial hypertension, hyperhomocysteinemia, and oxidative stress. In this review, our aim was to clarify the mechanism underlying interactions between hosts (animal or human) and probiotics and the beneficial effects of probiotics on human health.

• Korean Journal of Animal Reproduction
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• v.20 no.2
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• pp.119-126
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• 1996

This study was carried out to determine the optimal condition for successful and efficient c cryopreservation of zygotes, 1-cell embryos, using EFS40 which was 40% (v/v) ethylene glycol diluted in DPBS medium containing 30% Fic-oll (w/v) and 0.3 M sucrose. After mouse zygote produced by IVF was vitrified by two freezing methods, the post-warming survival rates of 1-cell zygotes were assessed as cleavage to the 2-cell stage and development into the hatching blastocysts at 5 day. In the one-step method, when embryos were directly exposed to the vitrification solution at 25$^{\circ}C$ for 1 min., survival and development rates of zygotes were 85.5% and 31.9% In the two-step method, embryos were equilibrated with a dilute 20% EG for 1, 3, 5 min. before 1 min. exposure to EFS40, re-spectively. However, the rates of development (17.7, 3.3, 0%) were lower than that of one-step method. The highest survival rate (95.9%) was obtained by one-step method which exposes embryos in EFS40 for 30 sec. In this condition, 63. 8% of cleaved 2-cell developed into hatching blastocysts. In the cell number of Total and ICM using differential labelling technique, there are no significant differences in the cell number of Total and ICM between blastocysts devel oped in vitrified-thawed embryos (63.2${\pm}$16.9, 1 13.5${\pm}$4.0) and control balstocysts (54.0${\pm}$15.2, 1 12.3${\pm}$4.6). Therefore, these results show that mouse zygotes can be successfully cryopreserved by a simple vitrification method although developmental rates of vitrified embryos were reduced. In conclusion, this proposed vitrifi cation procedures can be useful in the cryopreservation of mouse IVF zygotes.

• Journal of Korea Water Resources Association
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• v.42 no.1
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• pp.33-50
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• 2009

The impact on hydrologic components considering future potential climate, land use change and vegetation cover information was assessed using SLURP (Semi-distributed Land-Use Runoff Process) continuous hydrologic model. The model was calibrated (1999 - 2000) and validated (2001 - 2002) for the upstream watershed ($260.4\;km^2$) of Gyeongancheon water level gauging station with the coefficient of determination and Nash-Sutcliffe efficiency ranging from 0.77 to 0.60 and 0.79 to 0.60, respectively. Two GCMs (MIROC3.2hires, ECHAM5-OM) future weather data of high (A2), middle (A1B) and low (B1) emission scenarios of the IPCC (Intergovernmental Panel on Climate Change) were adopted and the data was corrected by 20C3M (20th Century Climate Coupled Model) and downscaled by Change Factor (CF) method using 30 years (1977 - 2006, baseline period) weather data. Three periods data of 2010 - 2039 (2020s), 2040 - 2069 (2050s), 2070 - 2099 (2080s) were prepared. To reduce the uncertainty of land surface conditions, future land use and vegetation canopy prediction were tried by CA-Markov technique and NOAA NDVI-Temperature relationship respectively. MIROC3.2 hires and ECHAM5-OM showed increase tendency in annual streamflow up to 21.4 % for 2080 A1B and 8.9 % for 2050 A1B scenario respectively. The portion of future predicted ET about precipitation increased up to 3 % in MIROC3.2 hires and 16 % in ECHAM5-OM respectively. The future soil moisture content slightly increased compared to 2002 soil moisture.

• Journal of The Korean Association For Science Education
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• v.38 no.4
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• pp.541-553
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• 2018

The purpose of this study is to explore the relationship between epistemic goals, epistemic considerations and complexity of reasoning of science high school students in an open inquiry and to explore the context on how open inquiry compares with the characteristics of an authentic scientific inquiry. Two teams were selected as focus groups and a case study was conducted. The findings are as follows: First, the contexts, such as 'sharing the value for the phenomenon understanding, reflection on the value of the research, task characteristics that require collaboration and consensus, and sufficient communication opportunities,' promote epistemic goals and considerations. On the other hand, contexts such as 'lack of opportunity for critical review of related literature and environmental constraints' lowered epistemic sides. Second, epistemic goals and considerations influenced the reasoning complexity. The goal of 'scientific sense making' led to reasoning that pose testable hypotheses based on students' own questions. The high justification considerations led to purposely focusing attention to the control designs and developing creative experimental know-how. The high audience considerations led to defending their findings through argumentation and suggesting future research. On the other hand, the goal of 'doing the lesson' and the low justification considerations led to reasoning that did not interpret the meaning of the data and did not control the limit of experiment. The low audience considerations led to reasoning that did not actively defend their findings and not suggest future research. The results of this study suggest that guidance should provide communication and critical review opportunities.