• Restorative Dentistry and Endodontics
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• v.24 no.1
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• pp.100-115
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• 1999

The purpose of this study was to investigate the distribution of calcitonin gene-related peptide containing nerve fibers in rat pulp after dentinl injury by means of immunohistochemistry and confocal laser scanning microscope. The Spague-Dawley rats weighing about 250-300gm were used. The animals were devided into normal control and experimental groups. Experimental animals were sacrified 1, 2, 4, 7, 10, 21days after dentinal injury (dentin cutting, and then acid etching with 35% phosphoric acid) on the maxillary molar teeth. The maxillary teeth and alveolar bone were removed and immersed in the 4% paraformaldehyde in 0.1M phosphate buffer (pH 7.4), then were decalcified with 15% formic acid for 10 days. Serial frozen $50{\mu}m$ thick sections were cut on a cryostat. The rabbit CGRP antibody was used as a primary antibody with a dilution of 1:2000 in 0.01M PB. The sections were incubated for 48 hours at $4^{\circ}C$, and placed into biotinylated antirabbit Ig G as a secondary anti body with dilution of 1:200 in 0.01M PB and incubated in ABC(avidin-biotin complex). The peroxidase reaction was visualized by incubating the sections in 0.05% 3,3 diaminobenzidine tetrahydrochloride containing 0.02% $H_2O_2$. For the confocal laser scanning microscopic examination, Primary antibody reaction was same as immunoperoxidase stainning, but fluorescein isothiocyanate(FITC)-conjugate antirabbit IgG as a secondary antibody was used. The confocal laser scanning microscope was used for the examination. A series of images of optical sections was collected with a 20x objective at $3{\mu}m$ intervals throughout the depth of specimen. FITC fluerescence was registrated through a 488nm and 568nm excitation filter, and images were saved on optical disk. The stereoscopic images and three dimentionnal images were reconstructed by computer software, and then were analyzed. The results were as follows : 1. In normal control group, CGRP containing nerve fibers were coursed through the root with very little branching, and then formed a dense network of terminals in coronal pulp. 2. A slight increase in CGRP containing nerve fibers at 1 and 2day postinjury was noted subjacent to the injury site. In the 4day group, there were an extensive increase in the number of reactive fibers, followed by a partial return toward normal levels at 7~10 day postinjury, and return by 21days. 3. The sprouting of the CGRP containing nerve fibers was evident within 2day after dentinal injury, and by 4days there was a maximal increased, but was decreased at 7days and returned to normal 10~21 day postinjury. 4. In confocal laser scanning microscopic exammination, the distinct distribution pattern and sprouting reaction of CGRP containing nerve fibers were observed in stereoscopic images and three dimentional images. These results suggest that CGRP containing nerve fiber can be important role in the response to dental injury and pain regulation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.15 no.2
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• pp.171-177
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• 1982

Optical properties of sea water were studied in the western channel of the Korea Strait, based on the data obtained from fifteen oceanographic stations in July, 1980. Submarine daylight intensity was measured at intervals of 5m depth in the upper 70m layer by using the underwater irradiameter (Kahlsico $\#268_{WA}360$). The mean absorption coefficients of the sea water were shown as $0.098(0.063\sim0.183),\;0.129(0.090\sim0.270), 0.081(0.044\sim0.142),\;and 0.087(0.036\sim0,142)$ for clear, red, green, and blue color respectively. The transparency ranged from 11.5 to 24m(mean 18.3m). The mean water color in this area was $3.5(3\sim4)$ in Forel scales. The relation between absorption coefficient $(\kappa)$ and transparency (D) was $\kappa=1.72/D,\;\kappa=2.33/D,\;\kappa=1.41/D,\;and \kappa=1.44/D$ for clear, red, green, and blue color respectively. The rates of light penetration for clear, red, green, and blue color in four different depths were computed with reference to the surface light intensity respectively. The mean rates of light penetration in proportion to depths were as follows; clear : $57.90\% (5m),\;23.40\%\;(15m),\;6.23\%\;(30m),\;1.00\%\;(50m).$ $red\;:\;48.95\%\;(5m),\;14,81\%\;(15m),\;2.76\%\;(30m),\;0.28\%\;(50m).$ $green:\;63.20\%\;(5m),\;30.47\%\;(15m),\;10.03\%\;(30m),\;2.24\%\;(50m).$ $blue\;:\;62.70\%\;(5m),\;30.00\%\;(15m),\;9.75\%\;(30m),\;1.70\%\;(50m)$

• Korean Journal of Remote Sensing
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• v.20 no.2
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• pp.77-89
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• 2004

The spatial and temporal variations of aerosol optical depth (AOD) over Northeast Asia regions have special importance in the aerosol research for estimation of aerosol radiative forcing parameters and climate change. Aerosol optical and physical properties (AOD and ${\AA}$ngstrom parameter) have been investigated by using Moderate Resolution Imaging Spectroradiometer (MODIS) and Total Ozone Mapping Spectrometer (TOMS) Aerosol Index (AI) to estimate aerosol characteristics over the study region during 2001. Additionally, aerosol characteristics over the Korean peninsular during Aerosol Characteristic Experiment in Asia (ACE-Asia) Intensive Observation Period (IOP) have been investigated by using satellite observations. The results showed that the daily-observed aerosol data indicate seasonal variations with relatively higher aerosol loading in the spring and very low during the winter. The typical Asian dust case showed higher AOD (>0.7) with lower Angstrom exponent (<0.5) and higher AI (>0.5) that is mainly due to the composition of coarse particles in the springtime. Mean AOD for 2001 at 4 different places showed 0.65$\pm$0.37 at Beijing, 0.31$\pm$0.19 at Gosan, 0.54$\pm$0.26 at Seoul, and 0.38$\pm$0.19 at Kwangju, respectively. An interesting result was found in the present study that polluted aerosol events with small size dominated-aerosol loading around the Korean peninsular are sometimes observed. The origin of these polluted aerosols was thought to East China. Aerosol distribution from satellite images and trajectory results shows the proof of aerosol transport. Therefore, aerosol monitoring using satellite data is very useful.

• Journal of the Korean earth science society
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• v.33 no.2
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• pp.139-147
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• 2012

Mongolia's solar-meteorological resources map has been developed using satellite data and reanalysis data. Solar radiation was calculated using solar radiation model, in which the input data were satellite data from SRTM, TERA, AQUA, AURA and MTSAT-1R satellites and the reanalysis data from NCEP/NCAR. The calculated results are validated by the DSWRF (Downward Short-Wave Radiation Flux) from NCEP/NCAR reanalysis. Mongolia is composed of mountainous region in the western area and desert or semi-arid region in middle and southern parts of the country. South-central area comprises inside the continent with a clear day and less rainfall, and irradiation is higher than other regions on the same latitude. The western mountain region is reached a lot of solar energy due to high elevation but the area is covered with snow (high albedo) throughout the year. The snow cover is a cause of false detection from the cloud detection algorithm of satellite data. Eventually clearness index and solar radiation are underestimated. And southern region has high total precipitable water and aerosol optical depth, but high solar radiation reaches the surface as it is located on the relatively lower latitude. When calculated solar radiation is validated by DSWRF from NCEP/NCAR reanalysis, monthly mean solar radiation is 547.59 MJ which is approximately 2.89 MJ higher than DSWRF. The correlation coefficient between calculation and reanalysis data is 0.99 and the RMSE (Root Mean Square Error) is 6.17 MJ. It turned out to be highest correlation (r=0.94) in October, and lowest correlation (r=0.62) in March considering the error of cloud detection with melting and yellow sand.

• Korean Journal of Remote Sensing
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• v.34 no.2_1
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• pp.237-248
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• 2018

The vertical distribution of hydrometeor before precipitation near the cloud base has been analyzed using a scanning lidar, rawinsonde data, and Cloud-Resolving Storm Simulator (CReSS). This study mostly focuses on 13 Desember 2016 only. The typical synoptic pattern of lake-effect snowstorm induced easterly in the Yeongdong region. Clouds generated due to high temperature difference between 850 hPa and sea surface (SST) penentrated in the Yeongdong region along with northerly and northeasterly, which eventually resulted precipitation. The cloud base height before the precipitation changed from 750 m to 1,280 m, which was in agreement with that from ceilometer at Sokcho. However, ceilometer tended to detect the cloud base 50 m ~ 100 m below strong signal of lidar backscattering coefficient. As a result, the depolarization ratio increased vertically while the backscattering coefficient decreased about 1,010 m~1,200 m above the ground. Lidar signal might be interpreted to be attenuated with the penetration depth of the cloud layer with of nonspherical hydrometeor (snow, ice cloud). An increase in backscattering signal and a decrease in depolarization ratio occured in the layer of 800 to 1,010 m, probably being associated with an increase in non-spherical particles. There seemed to be a shallow liquid layer with a low depolarization ratio (<0.1) in the layer of 850~900 m. As the altitude increases in the 680 m~850 m, the backscattering coefficient and depolarization ratio increase at the same time. In this range of height, the maximum value (0.6) is displayed. Such a result can be inferred that the nonspherical hydrometeor are distributed by a low density. At this time, the depolarization ratio and the backscattering coefficient did not increase under observed melting layer of 680 m. The lidar has a disadvantage that it is difficult for its beam to penetrate deep into clouds due to attenuation problem. However it is promising to distinguish hydrometeor morphology by utilizing the depolarization ratio and the backscattering coefficient, since its vertical high resolution (2.5 m) enable us to analyze detailed cloud microphysics. It would contribute to understanding cloud microphysics of cold clouds and snowfall when remote sensings including lidar, radar, and in-situ measurements could be timely utilized altogether.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.3
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• pp.105-112
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• 2009

This study has attempted to facilitate various new technologies related to indoor containers and develop a desirable planting environment after investigating the growth (including root growth) of shade-tolerant landscape plants under slit processing, a natural indoor ventilation system. The following results were found: In terms of the shoot growth of Fatsia japonica in a slit container, no distinctive difference was observed in comparison with the control group. However, growth was good when the container 250mm tall or taller. Therefore, it was verified that optical soil depth is more important than slit processing in shoot growth of Fatsia japonica. In Fatsia japonica root length was observed as follows: Control 2(250mm) > Slit 2(250mm) > Control 1(195mm) > Slit 3(360mm) > Control 3(360mm) > Slit 1(195mm). The largest growth was observed in Control 2(250mm), which had no slit processing. In term of root width, this was lower than the initial value in all groups, which means that the root grew vertically, not horizontally. In terms of plant height of Ophiopogon japonicus, a gradual increase was observed in the control group that had no slit processing. No significant growth was detected in the slit system, however. In terms of shoot number, slit containers were generally higher than the control group. In terms of fresh and dry weights, on the contrary, slit containers were mostly lower than the control group. In Ophiopogon japonicus, root length was observed as follows: Slit 2(250mm) > Slit 1(195mm) > Control 2(250mm) > Control 3(360mm) > Slit 3(360mm) > Control 1(195mm). In Ardisia japonica, slit containers were mostly greater than control group in terms of plant height. The greatest plant height was observed at Slit 2(250mm) instead of Slit 1(195mm) and Slit 3(360mm). Except for plant height and shoot number, however, no significant shoot and root growth was observed. Root length was observed as follows: Slit 2(250mm) > Slit 3(360mm) > Control 3(360mm) > Slit 1(195mm) > Control 2(250mm) > Control 1(195mm). Therefore, root length in slit containers was mostly greater than in the control group. The width of root, however, declined in general.

• Restorative Dentistry and Endodontics
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• v.35 no.3
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• pp.164-172
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• 2010

During a composite resin restoration, an anticipating contraction gap is usually tried to seal with low-viscosity resin after successive polishing, etching, rinsing and drying steps, which as a whole is called rebonding procedure. However, the gap might already have been filled with water or debris before applying the sealing resin. We hypothesized that microleakage would decrease if the rebonding agent was applied before the polishing step, i.e., immediately after curing composite resin. On the buccal and lingual surfaces of 35 extracted human molar teeth, class V cavities were prepared with the occlusal margin in enamel and the gingival margin in dentin. They were restored with a hybrid composite resin Z250 (3M ESPE, USA) using an adhesive AdperTM Single Bond 2 (3M ESPE). As rebonding agents, BisCover LV (Bisco, USA), ScotchBond Multi-Purpose adhesive (3M ESPE) and an experimental adhesive were applied on the restoration margins before polishing step or after successive polishing and etching steps. The infiltration depth of 2% methylene blue into the margin was measured using an optical stereomicroscope. The correlation between viscosity of rebonding agents and mciroleakage was also evaluated. There were no statistically significant differences in the microleakage within the rebonding procedures, within the rebonding agents, and within the margins. However, when the restorations were not rebonded, the microleakage at gingival margin was significantly higher than those groups rebonded with 3 agents (p < 0.05). The difference was not observed at the occlusal margin. No significant correlation was found between viscosity of rebonding agents and microleakage, except very weak correlation in case of rebonding after polishing and etching at gingival margin.

• Korean Journal of Remote Sensing
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• v.37 no.5_1
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• pp.959-974
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• 2021

Forel-Ule Index (FUI) is an index which classifies the colors of inland and seawater exist in nature into 21 gradesranging from indigo blue to cola brown. FUI has been analyzed in connection with the eutrophication, water quality, and light characteristics of water systems in many studies, and the possibility as a new water quality index which simultaneously contains optical information of water quality parameters has been suggested. In thisstudy, Ocean Colour-Climate Change Initiative (OC-CCI) based 4 km FUI was spatially downscaled to the resolution of 500 m using the Geostationary Ocean Color Imager (GOCI) data and Random Forest (RF) machine learning. Then, the RF-derived FUI was examined in terms of its correlation with various water quality parameters measured in coastal areas and its spatial distribution and seasonal characteristics. The results showed that the RF-derived FUI resulted in higher accuracy (Coefficient of Determination (R²)=0.81, Root Mean Square Error (RMSE)=0.7784) than GOCI-derived FUI estimated by Pitarch's OC-CCI FUI algorithm (R²=0.72, RMSE=0.9708). RF-derived FUI showed a high correlation with five water quality parameters including Total Nitrogen, Total Phosphorus, Chlorophyll-a, Total Suspended Solids, Transparency with the correlation coefficients of 0.87, 0.88, 0.97, 0.65, and -0.98, respectively. The temporal pattern of the RF-derived FUI well reflected the physical relationship with various water quality parameters with a strong seasonality. The research findingssuggested the potential of the high resolution FUI in coastal water quality management in the Korean Peninsula.

• Korean Journal of Remote Sensing
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• v.37 no.2
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• pp.321-335
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• 2021

Particulate matter (PM10 and PM2.5 with a diameter less than 10 and 2.5 ㎛, respectively) can be absorbed by the human body and adversely affect human health. Although most of the PM monitoring are based on ground-based observations, they are limited to point-based measurement sites, which leads to uncertainty in PM estimation for regions without observation sites. It is possible to overcome their spatial limitation by using satellite data. In this study, we developed machine learning-based retrieval algorithm for ground-level PM10 and PM2.5 concentrations using aerosol parameters from Geostationary Ocean Color Imager (GOCI) satellite and various meteorological parameters from a numerical weather prediction model during January to December of 2019. Gradient Boosted Regression Trees (GBRT) and Light Gradient Boosting Machine (LightGBM) were used to estimate PM concentrations. The model performances were examined for two types of feature sets-all input parameters (Feature set 1) and a subset of input parameters without meteorological and land-cover parameters (Feature set 2). Both models showed higher accuracy (about 10 % higher in R2) by using the Feature set 1 than the Feature set 2. The GBRT model using Feature set 1 was chosen as the final model for further analysis(PM10: R2 = 0.82, nRMSE = 34.9 %, PM2.5: R2 = 0.75, nRMSE = 35.6 %). The spatial distribution of the seasonal and annual-averaged PM concentrations was similar with in-situ observations, except for the northeastern part of China with bright surface reflectance. Their spatial distribution and seasonal changes were well matched with in-situ measurements.

• Journal of the Korean earth science society
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• v.42 no.3
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• pp.278-295
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• 2021

China's shutdown due to COVID-19 in 2020 reduced air pollutant emissions, which is located on the windward side of South Korea. The positive temperature anomaly and negative zonal wind anomaly from northern Mongolia to South Korea through eastern China presented warm and stationary air masses during January and February 2020. Decreased concentrations of PM10, NO₂, and O₃ were measured at Seokmo-ri and Pado-ri, located in the central-western region of South Korea, due to decreased emissions in China from January to March 2020. After China's shutdown from January to March 2020, in Pado-ri, the ratio of monthly average concentrations in that period with those of PM10 and O₃ in the last four years decreased by approximately 0.7-4.7% and 9.2-22.8%, respectively. In January 2020, during the Lunar New Year holidays in China, concentrations of PM10, NO₂, and O₃ at Seokmo-ri and Pado-ri decreased just as much as it did during the same period in the last four years. However, average concentrations in January 2020 decreased before and after the Lunar New Year holidays in China when compared with those in January of the last four years. In Seokmori, ratios of actual and predicted values (${\bar{O}_s$/M) for PM10, NO₂, and O₃ concentrations were calculated as 70.8 to 89.7%, 70.5 to 87.1%, and 72.5 to 97.1%, respectively, during January and March 2020. Moreover, those of Pado-ri were 79.6 to 93.5%, 67.7 to 84.9%, and 83.7 to 94.6%, respectively. In January 2020, the aerosol optical depth (AOD) data showed a higher distribution than that of the last four years due to photochemical reactions in regions from northern Mongolia to eastern China and the Korean Peninsula. However, the decrease in AOD values compared with those of the last four years was attributed to the decrease in emissions of precursors that generate secondary aerosols in China during March 2020.