• Journal of Korean Society for Atmospheric Environment
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• v.23 no.5
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• pp.563-574
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• 2007

There seems to be a consensus among most people that visibility impairment is the most obvious indicator of air pollution. While considerable evidence on the association between air pollution and health outcomes including death and disease have been established, based on industrial complex areas or huge urban cities, time-series, case-crossover and cohort studies, scarce literature exists on the direct evidence for the association between visibility and adverse health outcomes. Our study is assessed the effect of air pollution measured by visibility impairment on respiratory mortality over a period of six years. Relative risks in respiratory deaths were estimated by a Poisson regression model of daily deaths between $1999{\sim}2004$. Daily counts of respiratory deaths as dependent variable was modelled with daily 24-hr mean visibility measurements (kilometers) as independent variable by means of Poisson regression. This model is controlled for confounding factors such as day of weeks, weather variables, seasonal variables and $PM_{10}$. The results in this study is observed the statistically significant association between an inverse health effect and visibility during the study period for respiratory mortality (percentage change in the relative risk for all aged -0.57%, 95% Cl, $-1.01%{\sim}-0.12%$; for $0{\sim}15$ aged -7.12%, 95% Cl, $-13.29%{\sim}-0.51%$; for 65+ aged -0.43%, 95% Cl, $-0.93%{\sim}-0.06%$ per 1 km increased in visibility). The effect size was much reduced during warm season. Visibility impairment resulting from air pollution is strongly associated with respiratory mortality, especially for children may be spent at outdoor. Our result provides a quick and useful indicator for eliciting the contribution of air pollution to the excess risk of respiratory mortality in Seoul, Korea.

• Journal of Korea Water Resources Association
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• v.42 no.7
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• pp.547-558
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• 2009

General reliability assessment of levees embankment is performed with safety factors for rainfall characteristics and hydrologic and hydraulic parameters, based on the results of deterministic analysis. The safety factors are widely employed in the field of engineering handling model parameters and the diversity of material properties, but cannot explain every natural phenomenon. Uncertainty of flood analysis and related parameters by introducing stochastic method rather than deterministic scheme will be required to deal with extreme weather and unprecedented flood due to recent climate change. As a consequence, stochastic-method-based measures considering parameter uncertainty and related factors are being established. In this study, a variety of dimensionless cumulative rainfall curve for typhoon and monsoon season of July to September with generation method of stochastic temporal variation is generated by introducing Monte Carlo method and applied to the risk assessment of levee embankment using reliability index. The result of this study reflecting temporal and regional characteristics of a rainfall can be used for the establishment of flood defence measures, hydraulic structure design and analysis on a watershed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.1
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• pp.70-74
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• 2015

An LED plant factory farm is an alternative way to grow crops regardless of weather, season, and blight in such times of climate change. In recent years, it is a currently active and vibrant research field. The industry, which ranges from leaf vegetables to high value products, is expanding. This study was conducted to test tthe response of LED (Light-emitting diode) irradiation on the growth characteristics and ginsenoside levels indoors, in order to find out suitable light conditions. Ginseng seedling was transplanted from a styrofoam pot ($L{\times}W{\times}D$:$495{\times}315{\times}215mm$, inside diameter) into a closed plant production system in four blue LED (BL) and red LED (RL) different ratios of 1:1, 1;2, 1:3, 1:4 in a temperature range of $20{\sim}25^{\circ}C$, relative humidity of between 55 and 65%, and a 12-hour photoperiod. The LED irradiation shows the highest levels were found at 1:1 of BL and RL ratio at $61.21{\mu}mol\;s^{-l}m^{-2}$, 1:2 ratio $68.55{\mu}mol\;s^{-l}m^{-2}$, 1:3 ratio $63.85{\mu}mol\;s^{-l}m^{-2}$ and 1:4 ratio $62.41{\mu}mol\;s^{-l}m^{-2}$ from highest to lowest respectively. After analyzing from shoot and root 2 yers old ginseng plant which were cultivated under 1:3 irradiation of BL and RL ratio, it generally showed a positive effect under a 1:3 ratio of BL and RL.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.45-56
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• 2009

Current status on the occurrence and the management of the major disease, insect and mite pests were investigated in the organic or non-chemical pest control orchards from 2005 to 2009. Numbers of certified organic or non-chemical apple orchards were increased from 14 in 2005 to 78 in 2008. Severe damages on leaves and fruits occurred by the several diseases such as marssonina blotch, bitter rot, white rot, sooty blotch and flyspeck, and the several insect pests such as apple leaf-curling aphid, woolly apple aphid, oriental fruit moth and peach fruit moth on the almost certified organic or non-chemical pest control orchards. About 10 and 18 environmental-friendly materials were used to control diseases and insect or mite pests respectively. But, lime sulfur and bordeaux mixture to diseases and machine oil, plant oil mixed with egg yolk, and pheromone mating disruptions to insect pests were effective to control under the adequate conditions. At present, it is extremely difficult to produce organic apples in Korea. Growers must consider about and solve so many conditions on the cultivar, weather, local site, marketing and so on, before when they decide to change from conventional or IPM(Integrated Pest Management) to organic or non-chemical pest control orchards.

• Korean Journal of Agricultural and Forest Meteorology
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• v.13 no.1
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• pp.35-40
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• 2011

While high-definition precipitation maps with a 270 m spatial resolution are available for South Korea, there is little information on geospatial availability of precipitation water for the famine - plagued North Korea. The restricted data access and sparse observations prohibit application of the widely used PRISM (Parameter-elevation Regressions on Independent Slopes Model) to North Korea for fine-resolution mapping of precipitation. A hybrid method which complements the PRISM grid with a sub-grid scale elevation function is suggested to estimate precipitation for remote areas with little data such as North Korea. The fine scale elevation - precipitation regressions for four sloping aspects were derived from 546 observation points in South Korea. A 'virtual' elevation surface at a 270 m grid spacing was generated by inverse distance weighed averaging of the station elevations of 78 KMA (Korea Meteorological Administration) synoptic stations. A 'real' elevation surface made up from both 78 synoptic and 468 automated weather stations (AWS) was also generated and subtracted from the virtual surface to get elevation difference at each point. The same procedure was done for monthly precipitation to get the precipitation difference at each point. A regression analysis was applied to derive the aspect - specific coefficient of precipitation change with a unit increase in elevation. The elevation difference between 'virtual' and 'real' surface was calculated for each 270m grid points across North Korea and the regression coefficients were applied to obtain the precipitation corrections for the PRISM grid. The correction terms are now added to the PRISM generated low resolution (~2.4 km) precipitation map to produce the 270 m high resolution map compatible with those available for South Korea. According to the final product, the spatial average precipitation for entire territory of North Korea is 1,196 mm for a climatological normal year (1971-2000) with standard deviation of 298 mm.

• Korean Journal of Remote Sensing
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• v.34 no.2_2
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• pp.419-429
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• 2018

An unmanned autonomous maritime surface system can move the vehicle to the areas for observing the ocean accidents, disasters, and severe weather conditions. Detection and monitoring technologies have been developed by the converging of the regional and local surveillance system. Wave Glider, one of the autonomous maritime surface systems, is ocean-wave propelled autonomous surface vehicle and controlled using Iridium satellite communication. In this study, we carried out two-time Wave Glider observations for 2016 and 2017 summer in the East China Sea that the area was influenced by low-salinity water. We observed the sea surface warming effect due to the low-salinity water using the regional (satellite) and local (Wave Glider) surveillance system. We also monitored the effect of the typhoon and understood the change of the ocean-atmosphere environments in real-time. New unmanned surface system with autonomous system and high endurance structure can measure comprehensively and usefully a long observation in complicated ocean environments because of connecting with other surveillance systems.

• Korean Journal of Agricultural and Forest Meteorology
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• v.21 no.4
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• pp.307-316
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• 2019

In the agricultural sector, greenhouse gas emissions vary depending on the interaction of all ecosystem changes such as soil environment, weather environment, crop growth, and anthropogenic farming activities. Agricultural sector greenhouse gas emissions resulting from many of these interactions are highly variable. Uncertainty-based evaluation that defines the interval with confidence level of greenhouse gas emission and absorption is necessary to take account of the variance characteristics of individual emissions, but research on uncertainty evaluation method is insufficient. This study aims to decide on the effect of reducing N₂O emissions from upland soils using an uncertainty-based approach. An uncertainty-based approach confirmed whether there was a difference between confidence intervals in the 5 different fertilizer treatment groups to reduce greenhouse gas emissions. Unlike the statistically significant test with three repetition averages, the uncertainty-based approach method estimated in this study is able to estimate the confidence interval considering the distribution characteristics of the emissions, such as the dispersion characteristics of individual emissions. Therefore, it is considered that the reliability of emissions can be improved by statistically testing the variance characteristics of emissions such as the uncertainty-based approach. It is hoped that the direction of the uncertainty-based approach for the effect of reducing greenhouse gas emissions in agriculture will be helpful in the future development of agricultural greenhouse gas emission reduction technology, adaptation to climate change, and further development of sustainable eco-social system.

• Korean Journal of Ecology and Environment
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• v.47 no.3
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• pp.194-201
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• 2014

To elucidate which climate factors and what periods affect the time of breeding migration of Gori salamanders (Hynobius yangi), we have investigated relationships between the 5-years breeding monitoring data from 2006 to 2010 which had obtained in both natural and translocated breeding sites at Bongdae mountain, Gijang-gun, Busan-si and the matched climate data obtained from the weather station, approximately 25 km apart from the sites. Mean average and mean lowest temperatures during one month before the first breeding migration were related with the time of first female migration in the translocated site. Mean temperature variation and mean precipitation during 60~120 days before the first breeding migration affected the time of 30% male appearance at the natural site and the time of 30% female appearance at both natural and translocated sites. Climate factors were more closely related with female appearance than male and at the translocated site than at the natural site. Our results show that changes in mean temperature variation and mean precipitation rather than mean average temperature might more significantly affect the breeding migration of salamanders, female breeding migration is more closely related with climate factors, and the salamanders translocated could be more affected by climate changes than those in natural populations.

• Korean Journal of Agricultural and Forest Meteorology
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• v.14 no.3
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• pp.99-107
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• 2012

There has been increasing number of patients with asthma, rhinitis, and conjunctivitis due to the atmospheric pollution and global warming. In this study, we investigated daily observed number of pollens to establish a standardized method for the impact analysis of the climate changes on the number of daily pollens in Korea. Daily observed allergenic pollens of trees, weeds, and pine were analyzed during the period of 1998 to 2010 (except 2006) in Seoul, Busan, Daegu, Gwangju, Gangneung, and Jeju. They increased in large cities including Seoul during the last 12 years and the long-term trend may continue in the future. Daily concentration or amount of pollens was highly correlated with weather variables. Positive correlation was found between air temperature and the pollens although different relationships existed for different locations. Chill days were utilized to estimate the length of the flowering or pollen period. The pollen period of trees was shorter in the field when the winter temperature was low. This approach may be utilized to determine the quantitative change in length of the pollen season in the future.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.49 no.2
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• pp.29-37
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• 2012

An experiment for an optimized automatic greenhouse environment in a flower farming greenhouse by building a ubiquitous sensor network with various sensors was conducted and the results were evaluated. And various culturing environmental information and data in the greenhouse were collected and analyzed. Then, the greenhouse was designed to maintain the best culturing environment on the basis of existing recommended optimized figures. By measuring the growth of the crops in the greenhouse, A system which controls facilities in the greenhouse to maintain the best culturing environment in accordance with change in the environment was analyzed.Computer simulation result proced that we discovered that controlling the facilities and the artificial light source increased production, enhanced quality, reduced labor and heating cost immensely. The experiment has proved that the u-flower farming system can maximize the income of farm families by sending warning messages to users of this system when weather suddenly changes so that users may cope with such changes and maintain the best culturing environment.