• Korean Journal of Agricultural and Forest Meteorology
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• v.21 no.3
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• pp.146-157
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• 2019

One of the most distinctive features of the South Korean rural environment is that the variation of weather or climate is large even within a small area due to complex terrains. The Geospatial Schemes based on Topo-Climatology (GSTP) was developed to simulate such variations effectively. In the present study, we reviewed the progress of the geospatial schemes for production of farm-scale agricultural weather data. Efforts have been made to improve the GSTP since 2000s. The schemes were used to provide climate information based on the current normal year and future climate scenarios at a landscape scale. The digital climate maps for the normal year include the maps of the monthly minimum temperature, maximum temperature, precipitation, and solar radiation in the past 30 years at 30 m or 270 m spatial resolution. Based on these digital climate maps, future climate change scenario maps were also produced at the high spatial resolution. These maps have been used for climate change impact assessment at the field scale by reprocessing them and transforming them into various forms. In the 2010s, the GSTP model was used to produce information for farm-specific weather conditions and weather forecast data on a landscape scale. The microclimate models of which the GSTP model consists have been improved to provide detailed weather condition data based on daily weather observation data in recent development. Using such daily data, the Early warning service for agrometeorological hazard has been developed to provide weather forecasts in real-time by processing a digital forecast and mid-term weather forecast data (KMA) at 30 m spatial resolution. Currently, daily minimum temperature, maximum temperature, precipitation, solar radiation quantity, and the duration of sunshine are forecasted as detailed weather conditions and forecast information. Moreover, based on farm-specific past-current-future weather information, growth information for various crops and agrometeorological disaster forecasts have been produced.

• Science of Emotion and Sensibility
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• v.13 no.1
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• pp.121-128
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• 2010

This study is to analyze change of connectivity between brain positions caused by relaxation through EEG coherence. EEG spectrum analysis method has been used to analyze brain activity when relaxation was experienced. However, the spectrum analysis method has a limit that could not observe interactive reaction between brain-functional positions. Therefore, coherence between positions was analyzed to observe connectivity between the measurement positions in this study. Through the method, the reaction of the central nervous system caused by the emotion change was observed. Twenty-four undergraduates of both genders(12 males and 12 females) were asked to close their eyes and listen to the sound. During experiment, EEG was measured at eight positions. The eight positions were F3, F4, T3, T4, P3, P4, O1, and O2 in accordance with International 10-20 system. The sounds with white noise and without were used for relaxation experience. Subjective emotion was measured to verify whether or not they felt relaxation. Subjective emotion of participants were analyzed by ANOVA method(Analysis of Variance). In the result, it was proved that relaxation was subjectively evoked when participants heard sound. Accordingly, it was proved that relaxation could be enhanced by the mixed white noise. EEG coherence between the measurement positions was analyzed. T-test was performed to find its significant difference between relaxation and not-relaxation. In the results of EEG coherence, connectivity with occipital lobes has been increased with relaxation, and connectivity with parietal lobes has been increased with non-relaxed state. Therefore, brain connectivity has shown different pattern between relaxed emotion and non-relaxed emotion.

• The Korean Journal of Nuclear Medicine Technology
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• v.13 no.3
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• pp.31-42
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• 2009

Purpose: As the number of domestic medical institutions installing PET/CT is increasing rapidly, the transfer of PET/CT images among medical institutions is also increasing. Thus, it is necessary to collect the comparative SUV data from several medical institutions' PET/CT systems through a phantom study which semi-quantitatively compares the SUV on one bed, the change scale of the SUV on the slices, and the time of measuring. The phantom study to find differences among the SUVs from various PET/CT offers the opportunity to obtain the reliability of the SUV in PET/CT images. Materials and Methods: Ten PET/CT systems from medical institutions in Korea were used. To obtain the accurate data, the study has been using the radiation detector of Korea Research Institute of Standards and Science to verify. The internal structures of NEMA $phantom^{TM}$ were removed and Six thousand milliliters of distilled water which has 1mCi of $^{18}F$-FDG put into the phantom. The water was properly integrated with $^{18}F$-FDG using magnetic stirrer. The images were acquired at 60, 70, 80, 90, 100, 110 and 120-minutes for 3 minute each. Two hundred square centimeters of region of interests were placed and analyzed. To confirm the usefulness, the correction-table came out from patients' data. Results: The coefficient of variability of the SUV from -11.0 to 9.90 % fell into the range of international standards(${\pm}10%$) along with the SUV on a bed, the change scale of the SUV on the slices, and the time of measuring, except one PET/CT system. Using the data of the differences among the SUVs, we came to withdraw the correction-table ranging from 0.803 to 1.246. The correction-table was confirmed its usefulness through Linear Regression Analysis which was applied to normal cases. Conclusions: Although studies have been made on the variation of the SUV, there is little attention on the standardization of the SUV. Based on this study of the quantitatively comparable data about the SUV accommodating the correction-table, it would help to have more corrective diagnosis.

• Korean Journal of Environment and Ecology
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• v.31 no.2
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• pp.135-151
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• 2017

Waterbirds were surveyed once a week from Oct. 2015 to Apr. 2016 to study the conditions of temperature of staying waterbirds on Wonju-Stream. The population staying on Wonju-Stream was in inverse proportion to the temperature change; birds increased as the temperature went down, and showed the highest peak counts on the 16th(27-Jan) survey, which was the lowest in temperature. decreasing as the temperature rose. The total population of Wonju River water birds increased with increasing freezing rate in proportion to the freezing rate of nearby reservoirs and tributaries. To clarify the relation of the numbers of the birds to temperature fluctuation, the correlation of the first period of wintering (1st~16th) and that of the later period(17th~27th) as well as the whole period was surveyed, based on the 16th which was the lowest in temperature. While most wintering waterbirds showed a negative correlation to the temperature, Egretta garzetta, Phalacrocorax carbo, and Ardea cinerea were positive in temperature relativity. Anas poecilorhyncha was in the highest relation to temperature fluctuation showing (7D/H3A(r=-0.960, P<0.000000001)) at 1-16 correlation(Cor.), with the whole wintering waterbird species showing the maximum correlation at 4D/LA in the every correlation(1~27Cor.(r=-0.942, P<0.01), 1~16Cor.(r=-0.947, P<0.01), 16~27Cor.(r=-0.958, P<0.01)). Each waterbird showed the correlation to the temperature variation(AT, HT, LT) and th duration(1D~7D) depending on the species differently. Most species demonstrated a bigger correlation to the lowest temperature rather than to the highest temperature. During the first half period of the wintering with the temperature falling it showed a high correlation to the temperature at the duration of 4D~7D, While it was for D1~D3 during the next half period.

• Economic and Environmental Geology
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• v.50 no.4
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• pp.287-302
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• 2017

The carbonate rocks of the Daegi Formation are composed of the limestone at the upper and lower zones, and the dolomite at the middle zone, in which the upper zone has higher CaO content than others. The colors of carbonate rock in the Daegi Formation can be divided into five types; white, light brown, light gray, gray, and dark gray. The white to light gray colored rocks correspond to the high purity limestone with 53.15 ~ 55.64 wt. % CaO, and the light brown colored rocks contain 20.71 ~ 21.67 wt. % MgO. The bleaching of carbonate rocks are not related to CaO composition of the rocks, as light gray rocks tend to be higher in CaO content than those of the white rocks at the lower zone. The pelitic components are also occasionally increased in white limestone than light grey one. $Al_2O_3$ is one of the most difficult content to remove during hydrothermal processes, so the interpretation that the limestone is purified together with hydrothemral bleaching, has little merit. The wide range (over 16 ‰) of ${\delta}^{18}O_{SMOW}$, smaller variation (within 2 ‰) of ${\delta}^{13}C_{PDB}$ are apparent in both the upper and lower zones, which indicate the Daegi Formation had been affected overall by hydrothermal fluids. The K-Ar isotopic age of hydrothermal alteration in the GMI limestone mine is $85.1{\pm}1.7Ma$. Gradual change from grey through light grey to white limestone is accompaned by lower oxygen stable isotope values, which is major evidence that the hydrothermal effect is the main process of the bleaching. Although the Daegi Formation has suffered from hydrothermal activity and increase in whiteness, there is no clear evidence demonstrating the relationship between bleaching and high purity of limestone. The purification of limestone has nothing to do with the hydrothermal activity in this area. Instead, it should be considered that the change of sedimentary environment related to see-level fluctuation which can prevent deposition of pelitic components especially $Al_2O_3$ contrbuted to the formation of the high purity limestone in the upper zone of the Daegi Formation. Considering the evidences such as increase in CaO content of limestone by depth, gradual change from calcite to dolomite at the lower zones, and occurring the high purity limestone at the upper zone, the interpretation of sequence stratigraphic aspect to the formation of the high purity Daegi limestone appears to be more suitable than that of hydrothermal alteration origin.

• Journal of Radiation Protection and Research
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• v.7 no.1
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• pp.23-33
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• 1982

The characteristic thermoluminescence responses of Teflon thermoluminescent dosimeters to radiations have been studied by the variation of radiation qualities as well as the high dose radiations. The change in the sensitivity of TLDs for different radiation qualities were studied through not only the photon energy dependence but also the change of supralinearity on the photon energy dependence, by exposing $^{60}Co$ gamma rays, the effective X-rays of 44keV, 69keV, 108keV, and thermal neutron of 0.04 eV. The results were as the following: The TL response of $T-CaSO_4$: Dy as a function of absorbed dose was linear up to about 5 Gy, and the response beyond 5Gy was supralinear for $^{60}Co$ gamma rays. The supralinearity of T-LiF-7 became noticeably apparent more than that of $T-CaSO_4$:Dy and also the lower the LET of radiation became the higher the supralinear effects were. No supralinearity appeared for the thermal neutron irradiations equivalent to 10Gy of $^{60}Co$ gamma rays. The relative sensitivities (Rs), which depended on the doses of $^{60}Co$ gamma rays to the TLDs of T-LiF-7 and T-$CaSO_4$:Dy could be, respectively, approximated to the following empirical formula fitted by the least square method: $$R_{LiF}=1.021-0.04581\;logD+0.402(logD)^2-0.405(logD)^3,\;\;5{\times}10^3{\geq}D{\geq}1(Gy)$$ $$R_{CaSO_4}=0.976-0.3241\;logD+0.262(logD)^2-0.298(logD)^3,\;5{\times}10^3{\geq}D{\geq}1(Gy)$$.