• Journal of the Society of Cosmetic Scientists of Korea
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• v.48 no.4
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• pp.343-355
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• 2022

Customized cosmetics are continuously mentioned as cosmetics in response to changes in the social environment and trends that emphasize individuality. Therefore, in this study, four types of nanoemulsion ampoules corresponding to skin types were prepared by different ratios of nanoemulsion formulation and ampoule formulation, and the applicability as a customized cosmetic base was checked. Particle size, polydispersity index, zeta potential, and viscosity according to time for 90 d were measured for four nanoemulsion ampoules with different volatile residues, and turbiscan was measured as a method for evaluating the stability of a colloidal dispersion system. Finally, human usability satisfaction was evaluated. As a result, it was confirmed that four kinds of nanoemulsion ampoules had a higher amount of volatile residue in the dry skin test product than in the oily skin test product. The pH was in the range of 6.41 to 6.88, and the particle size was in the range of 170 to 174 nm, and the change after 90 d was within 1.2% of the maximum, and there was no specificity in particle size stability. It was confirmed that the polydispersity index was almost constant, and showed a particle size distribution close to monodispersity by showing a change within a value smaller than 0.21 in all test products. The zeta potential was initially -63 mV or more for all four types of test products, and although it showed a slight decrease with time, there was little change to the extent of a maximum decrease of 2.5%. Viscosity was initially in the range of 4,100 to 5,100 cps and showed a decreasing trend with time, showing a maximum decrease of 37.7%. In the turbiscan measurement, the turbiscan stability index, a measure of stability, was all below 1.0, indicating dispersion stability. In the usability satisfaction evaluation (6 points) of 4 nanoemulsion ampoules corresponding to skin type, oily skin product (5.42 ± 0.67 points) > neutral oily skin product (5.36 ± 0.67 points) > neutral dry skin product (5.15 ± 0.69 point) > dry skin product (4.75 ± 0.75 points) in the order of evaluation. Four types of nanoemulsion ampoules are physically stable and have confirmed their applicability as a customized cosmetic base according to skin type, and are expected to expand in various ways.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.3
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• pp.367-376
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• 2022

This study is a preliminary step to understand the reaction between various liquids and zeolite in the subduction zone environment. Stilbite, NaCa₄(Al₉Si₂₇)O₇₂·28(H₂O), was selected and high pressure study was conducted on compressional behavior by the pressure-transmitting medium (PTM). Water and NaHCO₃ solution that can exist in the subduction zone was used as PTM, and samples were pressurized from ambient to a maximum of 2.5 GPa. Below 1.0 GPa, both experiments show a low linear compressibility in the range of 0.001 to 0.004 GPa^-1 and a high bulk modulus of 220(1) GPa. This is presumably because the structure of the stilbite becomes very dense due to insertion of water molecules or cations into the channel. On the other hand, at 1.0 GPa or higher, the trends of the two experiments are different. In the water run, the linear compressibility of the c-axis is increased to 0.006(1) GPa^-1. In the NaHCO₃ run, the linear compressibility of the b- and c-axis is increased to 0.006(1) GPa^-1. The bulk modulus after 1.0 GPa shows values of 40(1) and 52(7) GPa in water and NaHCO₃ run, respectively, confirming that stilbite becomes more compressible than that before 1.0 GPa. It is caused by the migration of cations and water molecules inside the channel, as the water molecules in the PTM start to freeze and stop to insert toward the channel at 1.0 GPa or more. In the NaHCO₃ run, it is assumed that the distribution of extra-framework species inside the structure is changed by substitution of the Na⁺ cation. It can be expected from tendency of the relative intensity ratio of the (001) and (020) peaks which show a different from that of the water run.

• Korean Journal of Environmental Biology
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• v.39 no.4
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• pp.526-535
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• 2021

Spatial sampling design plays an important role in GIS-based modeling studies because it increases modeling efficiency while reducing the cost of sampling. In the field of agricultural systems, research demand for high-resolution spatial databased modeling to predict and evaluate climate change impacts is growing rapidly. Accordingly, the need and importance of spatial sampling design are increasing. The purpose of this study was to design spatial sampling of paddy fields (11,386 grids with 1 km spatial resolution) in Korea for use in agricultural spatial modeling. A stratified random sampling design was developed and applied in 2030s, 2050s, and 2080s under two RCP scenarios of 4.5 and 8.5. Twenty-five weather and four soil characteristics were used as stratification variables. Stratification and sample allocation were optimized to ensure minimum sample size under given precision constraints for 16 target variables such as crop yield, greenhouse gas emission, and pest distribution. Precision and accuracy of the sampling were evaluated through sampling simulations based on coefficient of variation (CV) and relative bias, respectively. As a result, the paddy field could be optimized in the range of 5 to 21 strata and 46 to 69 samples. Evaluation results showed that target variables were within precision constraints (CV<0.05 except for crop yield) with low bias values (below 3%). These results can contribute to reducing sampling cost and computation time while having high predictive power. It is expected to be widely used as a representative sample grid in various agriculture spatial modeling studies.

• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.2
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• pp.80-98
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• 2023

This study explores the effectiveness of various data preprocessing algorithms for improving subseasonal to seasonal (S2S) climate predictions from six climate forecast models and their Multi-Model Ensemble (MME) using a deep learning-based postprocessing model. A pipeline of data transformation algorithms was constructed to convert raw S2S prediction data into the training data processed with several statistical distribution. A dimensionality reduction algorithm for selecting features through rankings of correlation coefficients between the observed and the input data. The training model in the study was designed with TimeDistributed wrapper applied to all convolutional layers of U-Net: The TimeDistributed wrapper allows a U-Net convolutional layer to be directly applied to 5-dimensional time series data while maintaining the time axis of data, but every input should be at least 3D in U-Net. We found that Robust and Standard transformation algorithms are most suitable for improving S2S predictions. The dimensionality reduction based on feature selections did not significantly improve predictions of daily precipitation for six climate models and even worsened predictions of daily maximum and minimum temperatures. While deep learning-based postprocessing was also improved MME S2S precipitation predictions, it did not have a significant effect on temperature predictions, particularly for the lead time of weeks 1 and 2. Further research is needed to develop an optimal deep learning model for improving S2S temperature predictions by testing various models and parameters.

• Analytical Science and Technology
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• v.22 no.4
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• pp.285-292
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• 2009

It has been observed that, after long term storage, some ammunitions are misfired by tamping (combustionstopping) due to aging of the chemicals loaded in the ammunitions. Used in ammunitions are percussion powder which provides the initial energy, igniter which ignites the percussion powder, and a delay system that delays the combustion for a period of time. The percussion powder is loaded first, followed by the igniter and then the delay system, and the ammunitions explode by the energy being transferred in the same order. Tamping occurs by combustion-stopping of the igniter or insufficient energy transfer from the igniter to the delay system or the combustion-stopping of the delay system, which are suspected to be caused by low purity of the components, inappropriate mixing ratio, size distribution of particulate components, type of the binder, blending method, hydrolysis by the humidity penetrated during the long term storage, and chemical changes of the components by high temperature. Goal of this study is to find the causes of the combustion-stopping of the igniter and the delay system of the ammunitions after long term storage. In this study, a method was developed for testing of the combustion-stopping, and the size distributions of the particulate components were analyzed with field-flow fractionation (FFF), and then the mechanism of chemical change during long term storage was investigated by thermal analysis (differential scanning calorimetry), XRD (X-ray diffractometry), and XPS (X-ray photoelectron spectroscopy). For the ignition system, M (metal)-O (oxygen) and M-OH peaks were observed at the oxygen's 1s position in the XPS spectrum. It was also found by XRD that $Fe_3O_4$ was produced. Thus it can be concluded that the combustion-stopping is caused by reduction in energy due to oxidation of the igniter.

• Korean Journal of Ecology and Environment
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• v.56 no.3
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• pp.187-195
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• 2023

Almost all of the water from agricultural dams located to the upper of the Yeongsan river is supplied as irrigation water for farmland and thus is not discharged to the main stream of the river. Also, most of the irrigation water does not return to the river after use, adding to the lack of flow in the main stream. As a result, the water quality and aquatic health of the river have become the poorest among the four major rivers in Korea. Therefore, in this study, several strategies for water quality improvement of the river were developed considering pollution reduction and flow rate increase, and their effect analysis was performed using a water quality model. The results of this study showed that the target water quality of the Yeongsan river could be achieved if flow increase strategies (FISs) are intensively pursued in parallel with pollution reduction. The reason is because the water quality of the river has been steadily improved through pollution reduction but this method is now nearing the limit. In addition, rainfall-related FISs such as dam construction and water distribution adjustment may be less effective or lost if a megadrought continues due to climate change and then rainfall does not occur for a long time. Therefore, in the future, if the application conditions for the FISs are similar, the seawater desalination facility, which is independent of rainfall, should be considered as the priority installation target among the FISs. The reason is that seawater desalination facilities can replace the water supply function of dams, which are difficult to newly build in Korea, and can be useful as a climate change adaptation facility by preventing water-related disasters in the event of a long-term megadrought.

• Journal of the Korean earth science society
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• v.45 no.2
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• pp.121-135
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• 2024

This study examined the influence of near-surface atmospheric warming in the Arctic-East Asia region during spring (March-May) from 1991 to 2020 on the synoptic-scale meteorology of dust storm-induced dust days in Seoul, Korea, in response to the Arctic Oscillation. Increased springtime warming in the Arctic-East Asia region correlated with a reduction of six days in the occurrence of dust storm-induced dust days in Seoul, Korea, along with a decline in the intensity of these days by -1.6 ㎍ m^-3yr^-1 in PM₁₀ mass concentration. The declining number of dust storm-induced dust days in Korea during the 2010s was the result of synoptic-scale meteorological analysis, which showed increased high-pressure activity as indicated by the negative potential vorticity unit. Moreover, a distinct pattern emerged in the distribution of dust storm-induced dust days in Korea based on the Arctic Oscillation Index (AOI), showing an increase in negative AOI and a decrease in positive AOI. Although the northward shift of the polar jet weakened the southerly low-pressure system activity over Mongolia and northern China, a reinforced high-pressure system formed over the Chinese continent during dust-storm-induced dust days with a negative AOI. This resulted in both a decrease in the frequency of dust-storm-induced dust days and reduction in wind speeds, facilitating their transport from source regions to Korea. Conversely, on days with positive AOIs, an extensive warm and stagnant high-pressure system dominated mainland China, accompanied by further cooling of the northern segment of the polar jet. A notable decline in wind speed in the lower troposphere across the Mongolia-northern China-Korea region diminished the occurrence of dust storm-induced dust days and also weakened their long-range transport.

• The Journal of Engineering Geology
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• v.34 no.3
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• pp.403-413
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• 2024

This study aims to investigate the material properties of specimens made from pyrophyllite and pyrophyllite-aluminum mixed powders using high-speed, high-pressure dynamic compression technology. The aluminum powder exhibited a highly uniform particle size distribution ranging from 10 to 100 ㎛, whereas the pyrophyllite powder displayed four distinct particle size distributions: 0.1~1 ㎛, 1~10 ㎛, 80~100 ㎛, and 200~1,000 ㎛. Using high-speed, high-pressure dynamic compression technology with a drop time of approximately 0.34~0.4 seconds and a dynamic load of about 207 tonf, it was possible to fabricate pyrophyllite and pyrophyllite-aluminum mixed powder specimens with a volume of about 548 mm². The Shore hardness measurement results showed that specimen BG100 had an average of 43.7, BG90 had an average of 33.2, and BG85, BG80, BG75, and BG70 had an average of 31.0, indicating that the specimen with the least aluminum content exhibited the highest Shore hardness value. The thermogravimetric analysis revealed mass losses at two points: the first mass loss occurred at around 270℃ with a loss of approximately 1.45%, and the second mass loss occurred at around 600℃, where BG70 and BG80 showed a mass loss of about 2.53%, and BG75, BG85, and BG90 showed a mass loss of about 3.43%. Scanning electron microscopy analysis indicated that the microstructure of the specimens was similar regardless of the mixing ratio, with three elements-O, Si, and Al-being detected in all specimens. The mapping analysis of BG90 revealed an oxygen weight ratio of 50.80%, silicon weight ratio of 37.36%, and aluminum weight ratio of 11.85%. In the case of BG85, the results were 43.09% oxygen, 43.50% silicon, and 13.41% aluminum; for BG80, the results were 44.83% oxygen, 40.30% silicon, and 14.87% aluminum; for BG75, the results were 44.71% oxygen, 35.49% silicon, and 19.80% aluminum; and for BG70, the results were 34.95% oxygen, 35.73% silicon, and 29.32% aluminum.

• Tuberculosis and Respiratory Diseases
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• v.46 no.5
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• pp.674-684
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• 1999

Background : It has been generally known that the incidence of lung cancer is higher in the patients with idopathic pumonary fibrosis (IPF) than those in general population. The reported incidence was variable from 4.8 to 43.2%. There were controversies on the most frequent cell type (squamous cell carcinoma vs. adenocarcinoma) and no study was done about the real concordance of cancer and the fibrotic lesion. And the pulmonary fibrosis may influence not only the development of cancer but also the treatment and prognosis of the cancer, but there was no report on that point. Method : Total 63 patients ($66.8{\pm}7.8$ year, M : F=61 : 2) were diagnosed as IPF combined with lung cancer (IFF-CA) at Asan Medical Center. A retrospective analysis was done about the risk factors of the lung cancer, pulmonary function test, the site of cancer(especially the relationship of the cancer with the fibrotic lesion), the histologic types, and the stage of cancer. The histologic types were compared with those of 2,660 patients with lung cancer who were diagnosed at the same institute for the same period. The effect of IPF on the treatment of the cancer was evaluated with the survival time after the detection of lung cancer. Results : The lung cancer was found in 63(22.9%) out of 281 patients with IPF. But in most of them(45 patients), lung cancer was detected at the same time with IPF and only in 18 patients, the cancer was diagnosed during the follow-up($25.2{\pm}17.7$ months) of IPF. So in our study, 6.7% of patients with IPF developed lung cancer during the course of the disease. The age ($66.8{\pm}7.84$ vs. $63.4{\pm}11.1$ years), percentage of smoker (88.9 vs. 67.2%), and the male gender (96.8 vs. 67.6%) were significantly higher in IPF-CA compared with lone IPF (p<0.05). The odds ratio of smoking was 4.7 compared with non smoking IPF controls. The lung cancer was located more frequently in the upper lobe and 55.5% was in the periphery of lung. The cancer was developed in the fibrotic lesion in 23 patients (35.9%), and in the majority of the patients, the cancer was separated from the fibrosis. The cell type of the lung cancer in IPF-CA was squamous cell carcinoma 34.9%, adenocarcinoma 30.2%, small cell carcinoma 19.0%, large cell undifferenciated carcinoma 6.3%, and others 9.5%. No significant difference in the distribution of histologic type of the lung cancer was found between IPF-CA and lone lung cancer. There was no significant difference in demographic features, cell types, location and the stage of the cancer between the group with concurrent IPF-CA and the group with cancer diagnosed during the follow up of IPF. There was a tendency (but statistically not significant : p=0.081) of higher incidence of adenocarcinoma among the cancers developed in the fibrotic area(43.5%) (F-CA) than in the cancers in non-fibrotic area (22.5%) (NF-CA). The prognosis of the patients with F-CA was poor (median survival : 4 months) compared with the patients with NF-CA (7 months, p=0.013), partly because the prevalence of severe IPF (the extent of fibrosis in HRCT 50%) was higher in F-CA group. Conclusion : These data suggest that the lung cancer in the patients with IPF has similar features to the ordinary lung cancer.

• Journal of Preventive Medicine and Public Health
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• v.23 no.3 s.31
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• pp.296-308
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• 1990

The relationship between copper and mercury contents in the scalp hair and chronic schizophrenia was investigated. The samples of scalp hair were collected from 80 male chronic schizophrenic patients at the age from 20 to 29, who were hospitalized in the National Psychiatric Hospital in Seoul. As the control group, 69 males were collected from general population. Hair samples were taken from the napes and the Minnesota Multiple Personality Inventory (MMPI) was performed also. The copper and mercury contents were determined by an atomic absorption spectrophotometer. Significantly higher T-score of MMPI was seen in patients group for Hypochondriasis Scale (Hs), Depression Scale (D), Psychopathic Deviate Scale (Pd), Paranoia Scale (Pa), Psychasthenia Scale (Pt), Schizophrenia Scale (Sc) subscales than control group, and the frequency distribution by T-score was also significantly different between the patient and the control group for above scales. The content of copper in the hair of patient group was significantly lower than the control group. In the case of mercury, the mean value of patient group was significantly higher than control group. Between the value of copper and mercury, statistically significant negative correlation (r=-0.25) was found. When grouped by the T-score of MMPI, there was no difference of copper contents between T-score subgroup at all MMPI scale. But the mercury contents showed significant difference between T-score subgroup at Pt, Sc scale. When compared between the group of above 70 T-score and the group of less than 70, the mercury contents of Pa, Pt, Sc scale of above 70 T-score group were significantly higher than the group of less than 70. In other scales, the mercury content of the above 70 group were higher than the group of less than 70 except Mf scale, although there were no statistscally significances. In D, Pa, Sc scales, as the T-score of MMPI increased, the contents of mercury also increased. When divided into the patient group and the control group, the copper contents of the patient groups were significantly lower than the control group at each T-score scale in most MMPI scales. In the case of mercury, the value of patient group were significantly higher than the control group in the less than 44 scale of D, in the $60{\sim}69$ scale of Pd, in the $45{\sim}59$ scale of Mf, in the $60{\sim}69$ scale of Ma, in the less than 44 of Si. These results suggest that the effects of the deficiency of copper or high intake of mecury on schizophrenia and personality may be of possible value. Thus further studies are necessary to determine whether schizophrenia and personality formation would be attributed to copper deficiency or mercury intake.