• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.27 no.2
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• pp.63-70
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• 2021

As the government strengthens its policy of separating and discharging packaging materials, consumers are increasingly dissatisfied. In order to increase consumer participation in separate discharge policy of packaging materials, it is necessary to increase the willingness to participate by reducing potential consumer problems such as removal of packaging labels. This study conducted a survey of 300 consumers aged 14 and over who recycle and discharge directly from their homes. Ninety-nine percent of consumers said PET bottles are released separately. However, only 65% of consumers removed labels (attachment labels, shrink labels) and other materials (caps, vinyl coatings, tapes, handles, bases, etc.) during separate discharge process. Nearly 52% of consumers cited 'difficulty of separation' as the main reason for not removing labels and other materials. One-way ANOVA analysis showed that 'strong adhesion', 'removal initiation problem' and 'material strength' had high mean regardless of age, which are major factors impedes label removal. Using shrink labels with perforated lines rather than adhesive labels would be more beneficial to encouraging participation in separate discharge. However, if the shrink labels do not have perforated lines or are difficult to remove, adhesive labels are often easier to remove than shrink labels because of the strong cohesiveness of shrink labels. As a result, how easy it is for consumers to remove the label is more important than technological differences. In order to increase consumer participation in packaging material and label separations, improvements in structural design are needed along with the selection of materials that are easy to separate. This study is meaningful in examining consumer perceptions, deriving problems and suggesting directions for policy improvement.

• Korean Journal of Remote Sensing
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• v.37 no.5_2
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• pp.1259-1268
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• 2021

The 2nd Geostationary Ocean Color Imager (GOCI-II) is the successor to the Geostationary Ocean Color Imager (GOCI), which employs one near-ultraviolet wavelength (380 nm) and eight visible wavelengths(412, 443, 490, 510, 555, 620, 660, 680 nm) and three near-infrared wavelengths(709, 745, 865 nm) to observe the marine environment in Northeast Asia, including the Korean Peninsula. However, the multispectral radiance image observed at satellite altitude includes both the water-leaving radiance and the atmospheric path radiance. Therefore, the atmospheric correction process to estimate the water-leaving radiance without the path radiance is essential for analyzing the ocean environment. This manuscript describes the GOCI-II standard atmospheric correction algorithm and its initial phase validation. The GOCI-II atmospheric correction method is theoretically based on the previous GOCI atmospheric correction, then partially improved for turbid water with the GOCI-II's two additional bands, i.e., 620 and 709 nm. The match-up showed an acceptable result, with the mean absolute percentage errors are fall within 5% in blue bands. It is supposed that part of the deviation over case-II waters arose from a lack of near-infrared vicarious calibration. We expect the GOCI-II atmospheric correction algorithm to be improved and updated regularly to the GOCI-II data processing system through continuous calibration and validation activities.

• The Journal of Korean Academy of Prosthodontics
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• v.59 no.3
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• pp.271-280
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• 2021

Purpose. The aim of this study was to evaluate the relationship between the patient's occlusion and a cracked tooth by using T-scan occlusal analysis and a quantitative light-induced fluorescence (QLF) technology. Materials and methods. This study was carried out on 51 patients having cracked teeth between January, 2019 and December, 2020. The tooth crack was determined with a Q-ray pen and QLF parameters (ΔF_max and ΔR_max) were obtained by a Q-ray software. T-scan tests were conducted to all subjects and then, the occlusal force and disclosing time were analyzed. Mann-Whitney U test was performed to compare the occlusal force and disclosing time between cracked teeth groups and contra-lateral normal teeth groups (α = .05). Mann-Whitney U test was performed to compare ΔF_max and ΔR_max according to the results of cold/bite tests (α = .05). A Spearman correlation analysis was run to determine the relationship between ΔF_max or ΔR_max and occlusal force or disclosing time (α=.05). Results. The mean occlusal force and disclosing time were significantly higher on cracked teeth than on normal teeth (P < .05). The ΔF_max or ΔR_max were not significantly different according to the results of cold/bite tests (P > .05). There was no correlation between ΔF_max or ΔR_max and occlusal force or disclosing time (P > .05). Conclusion. There was a significant relationship between occlusion and cracked tooth syndrome. QLF has the potential to be a valuable tool for the diagnosis of tooth crack in clinical practice.

• Korean Journal of Remote Sensing
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• v.37 no.6_2
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• pp.1793-1801
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• 2021

From 2015 to June 2020, the backscattering coefficients of 532 and 1064 nm measured using LIDAR and the depolarization ratio at 532 nm were used to separate the backscattering coefficient at 532 nm as three types as PM₁₀, PM_2.5-10, PM_2.5 according to particle size. The mass extinction efficiency (MEE) of three types was calculated using the mass concentration measured on the ground. The overall mean values of the calculated MEE were 5.1 ± 2.5, 1.7 ± 3.7, and 9.3 ± 6.3 m²/g in PM₁₀, PM_2.5-10, and PM_2.5, respectively. When the mass concentration of PM₁₀ and PM_2.5 was low, higher than average MEE was calculated, and it was confirmed that the MEE decreased as the mass concentration increased. When the MEE was calculated for each type according to the mixing degree of Asian dust, PM_2.5-10 was twice at pollution aerosol as high as 2.1 ± 2.8 m²/g, compare to pollution-dominated mixture, dust-dominated mixture, and pure dust of 1.1 ± 1.8, 1.4 ± 3.3, 1.1 ± 1.5 m²/g, respectively. However, PM_2.5 MEE showed similar values irrespective of type: 9.4 ± 6.5, 9.0 ± 5.8, 10.3 ± 7.5, and 9.1 ± 9.0 m²/g. The MEE of PM₁₀ was 5.6 ± 2.9, 4.4 ± 2.0, 3.6 ± 2.9, and 2.8 ± 2.4 m²/g in pollution aerosol (PA), pollution-dominated mixture (PDM), dust-dominated mixture (DDM), and pure dust (PD), respectively, and increased as the dust ratio value decreased. Even if the same type according to the same mass concentration or Asian dust mixture was shown, as the PM_2.5/PM₁₀ ratio decreased, the MEE of PM_2.5-10 decreased and the MEE of PM_2.5 showed a tendency to increase.

• Journal of the Korean Society of Radiology
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• v.15 no.7
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• pp.991-998
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• 2021

The purpose of this study is to investigate the image quality of the SE-EPI and SSH-TSE technique for MR DWI. Datum were analyzed for 35 PACS transmission datum(Normal part: 12 males, 13 females, Cerebral Infarction: 10(5males and 5females), and average age 68±7.32), randomly selected patients who underwent MRDWI tests. The equipment used was Ingenia CX 3.0T, SSH_TSE and SE-EPI pulse sequence and 32 Ch. head coil were used for data acquisition. Image evaluation was performed on the paired t-test and Wilcoxon tests, and was considered significant when the p value was 0.05 or less. As a result of quantitative analysis of SNR for DWI images, the mean and standard deviation values of 4 parts (WM, GM, BG, Cerebellum) in ADC (s/mm2), Diffusion b=0, 1000 images were higher in SE-EPI techniques(ADC: 120.50 ± 40, b=0: 54.50 ± 35.91, b=1000: 91.61 ± 36.63) than in SSH-TSE techniques(ADC: 99.69 ± 31.10, b=0: 43.52 ± 25.00 , b=1000: 60.74 ± 24.85)(p<0.05). The CNR values for GM-WM, BG-WM sites were also higher in SE-EPI technique (ADC: 116.08 ± 43.30, b=0:27.23 ± 09.10, b=1000: 78.50 ± 16.56) than in SSH-TSE(ADC: 101.08 ± 36.81, b=0: 23.96 ± 07.79 , b=1000: 74.30 ± 14.22). As a visual evaluation of observers, ghost artifact, magnetic susceptibility artifacts and overall image quality for SE-TSE and SSH-TSE all yielded high results from SSH-TSE techniques(ADC:3.6 ± 0.1, 2.8 ± 0.2, b=0: 4.3 ± 0.3, 3.4 ± 0.1 b=1000: 4.3 ± 0.2, 3.5 ± 0.2, p=0.000). In conclusion, the SE-EPI technique obtained an superiority in SNR and CNR measurements using SSH-TSE, SE-EPI. In the qualitative analysis, the SSH-TSE pulse sequence was obtained a high result according to the pulse sequence characteristics.

• Korean Journal of Remote Sensing
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• v.37 no.6_1
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• pp.1739-1756
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• 2021

Atmospheric nitrogen dioxide (NO₂) is mainly caused by anthropogenic emissions. It contributes to the formation of secondary pollutants and ozone through chemical reactions, and adversely affects human health. Although ground stations to monitor NO₂ concentrations in real time are operated in Korea, they have a limitation that it is difficult to analyze the spatial distribution of NO₂ concentrations, especially over the areas with no stations. Therefore, this study conducted a comparative experiment of spatial interpolation of NO₂ concentrations based on two linear-regression methods(i.e., multi linear regression (MLR), and regression kriging (RK)), and two machine learning approaches (i.e., random forest (RF), and support vector regression (SVR)) for the year of 2020. Four approaches were compared using leave-one-out-cross validation (LOOCV). The daily LOOCV results showed that MLR, RK, and SVR produced the average daily index of agreement (IOA) of 0.57, which was higher than that of RF (0.50). The average daily normalized root mean square error of RK was 0.9483%, which was slightly lower than those of the other models. MLR, RK and SVR showed similar seasonal distribution patterns, and the dynamic range of the resultant NO₂ concentrations from these three models was similar while that from RF was relatively small. The multivariate linear regression approaches are expected to be a promising method for spatial interpolation of ground-level NO₂ concentrations and other parameters in urban areas.

• Korean Journal of Remote Sensing
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• v.37 no.6_1
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• pp.1767-1772
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• 2021

Global satellite observation surface albedo data over a long period of time are actively used to monitor changes in the global climate and environment, and their utilization and importance are great. Through the generational shift of geostationary satellites COMS (Communication, Ocean and Meteorological Satellite)/MI (Meteorological Imager sensor) and GK-2A (GEO-KOMPSAT-2A)/AMI (Advanced Meteorological Imager sensor), it is possible to continuously secure surface albedo outputs. However, the surface albedo outputs of COMS/MI and GK-2A/AMI differ between outputs due to Differences in retrieval algorithms. Therefore, in order to expand the retrieval period of the surface albedo of COMS/MI and GK-2A/AMI to secure continuous climate change monitoring linkage, the analysis of the two satellite outputs and errors should be preceded. In this study, error characteristics were analyzed by performing comparative analysis with ground observation data AERONET (Aerosol Robotic Network) and other satellite data GLASS (Global Land Surface Satellite) for the overlapping period of COMS/MI and GK-2A/AMI surface albedo data. As a result of error analysis, it was confirmed that the RMSE of COMS/MI was 0.043, higher than the RMSE of GK-2A/AMI, 0.015. In addition, compared to other satellite (GLASS) data, the RMSE of COMS/MI was 0.029, slightly lower than that of GK-2A/AMI 0.038. When understanding these error characteristics and using COMS/MI and GK-2A/AMI's surface albedo data, it will be possible to actively utilize them for long-term climate change monitoring.

• Korean Journal of Remote Sensing
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• v.37 no.2
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• pp.275-290
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• 2021

Sulfur dioxide (SO2) in the atmosphere is mainly generated from anthropogenic emission sources. It forms ultra-fine particulate matter through chemical reaction and has harmful effect on both the environment and human health. In particular, ground-level SO2 concentrations are closely related to human activities. Satellite observations such as TROPOMI (TROPOspheric Monitoring Instrument)-derived column density data can provide spatially continuous monitoring of ground-level SO2 concentrations. This study aims to propose a 2-step residual corrected model to estimate ground-level SO2 concentrations through the synergistic use of satellite data and numerical model output. Random forest machine learning was adopted in the 2-step residual corrected model. The proposed model was evaluated through three cross-validations (i.e., random, spatial and temporal). The results showed that the model produced slopes of 1.14-1.25, R values of 0.55-0.65, and relative root-mean-square-error of 58-63%, which were improved by 10% for slopes and 3% for R and rRMSE when compared to the model without residual correction. The model performance by country was slightly reduced in Japan, often resulting in overestimation, where the sample size was small, and the concentration level was relatively low. The spatial and temporal distributions of SO2 produced by the model agreed with those of the in-situ measurements, especially over Yangtze River Delta in China and Seoul Metropolitan Area in South Korea, which are highly dependent on the characteristics of anthropogenic emission sources. The model proposed in this study can be used for long-term monitoring of ground-level SO2 concentrations on both the spatial and temporal domains.

• Korean Journal of Breeding Science
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• v.49 no.2
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• pp.80-86
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• 2017

'Jungmo2501' (Avena sativa L.), a winter oat for forage use, was developed by the breeding team at the National Institute of Crop Science, RDA in 2010. The following is the characteristics of 'Jungmo2501' that is characterized as light green leaf, yellow brown culm and whitish yellow grain. The heading date of 'Jungmo2501' was about 3 days earlier than that of check cultivar 'Samhan'(May 7 and May 10, respectively). Its plant height was 11 cm longer than 103 cm of the check, and the leaf blade ratio of aerial parts was 26 % higher than the check (11.8% and 9.4%, respectively). The cold tolerance, resistance to lodging and wet injury of 'Jungmo2501' were similar to those of the check. The average forage dry matter yield of 'Jungmo2501' harvested at milk-ripe stage was 5% higher than the check ($15.5ton\;ha^{-1}$ and $14.7ton\;ha^{-1}$, respectively). 'Jungmo2501' was higher than the check in terms of protein content (6.6% and 5.9%, respectively), neutral detergent fiber (58.5% and 57.6%, respectively), and acid detergent fiber (34.5% and 32.1%, respectively), while total digestible nutrients was lower than the check (61.6% and 63.6%, respectively), and TDN yield was $0.37ton\;ha^{-1}$ more than that of the check ($9.71ton\;ha^{-1}$ and $9.34ton\;ha^{-1}$, respectively). The silage grade of 'Jungmo2501' estimated by Flig score showed level II, meaning good quality. Fall sowing cropping of 'Jungmo2501' is recommended only for areas where average daily minimum mean temperatures in January are higher than $-6^{\circ}C$.

• The Korean Journal of Vision Science
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• v.20 no.4
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• pp.553-560
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• 2018

Purpose : To investigate a disposal method of disposing contact lenses and the recognition of environmental pollution by micro plastics which may be caused by the wrong disposal method of domestic contact lens wearers. Methods : Two hundred sixty one adults(124 males, 137 females, mean age $21.48{\pm}3.14years$) were participated in this study. They were given the questionnaire survey on contact lenses purchasing place, type of contact lenses, duration of wearing contact lenses, the disposal method of disposing contact lenses and the recognition of the occurrence of environmental pollution. Results : It appeared that eyeglass shop(50.0%) and contact lens shop(48.3%) were the main purchasing places, and the most common type of contact lenses were disposable lenses(38.5%) and daily wearing lenses(52.5%). On the duration of wearing contact lenses they answered more than 5 years(29.3%), less than 1 year (26.0%), less than 1 year to less than 3 years (26.0%), and on wearing a contact lens during a week they did 1-2 days (32.0%), 1 week (28.0%), 5-6 days (22.4%) and 3-4 days (17.6%). It was shown "no(78.3%)" and "yes(21.7%)" to the questionnaire of whether they received information or education about a disposal method at the place where the contact lens was purchased, and "no(87.5%)" and "yes(12.5%)" to the questionnaire of whether they received information or education from schools, public institutions or public media such as the internet. As for the disposal methods, landfill waste(45.6%), recycled garbage(29.6%), and drainage(16.8%) from the sink or toilet responded in order. Although men were more educated and informed about disposal than women (t=3.63189, p<0.00001), women were more aware of environmental pollution(t=2.44269, p=0.01605). Conclusion : In order to reduce the environmental pollution issue caused by the contact lens which does not decompose at the sewage treatment facility and become micro plastics, it is urgent to provide information about correct disposal methods after using contact lenses and to educate contact lens wearers.