• Economic and Environmental Geology
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• v.55 no.6
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• pp.737-760
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• 2022

For the geological disposal of high-level radioactive wastes (HLW), an understanding of deep subsurface environment is essential through geological, hydrogeological, geochemical, and geotechnical investigations. Although South Korea plans the geological disposal of HLW, only a few studies have been conducted for characterizing the geochemistry of deep subsurface environment. To guide the hydrogeochemical research for selecting suitable repository sites, this study overviewed the status and trends in hydrogeochemical characterization of deep groundwater for the deep geological disposal of HLW in developed countries. As a result of examining the selection process of geological disposal sites in 8 countries including USA, Canada, Finland, Sweden, France, Japan, Germany, and Switzerland, the following geochemical parameters were needed for the geochemical characterization of deep subsurface environment: major and minor elements and isotopes (e.g., ³⁴S and ¹⁸O of SO₄^2-, ¹³C and ¹⁴C of DIC, ²H and ¹⁸O of water) of both groundwater and pore water (in aquitard), fracture-filling minerals, organic materials, colloids, and oxidation-reduction indicators (e.g., Eh, Fe²⁺/Fe³⁺, H₂S/SO₄^2-, NH₄⁺/NO₃^-). A suitable repository was selected based on the integrated interpretation of these geochemical data from deep subsurface. In South Korea, hydrochemical types and evolutionary patterns of deep groundwater were identified using artificial neural networks (e.g., Self-Organizing Map), and the impact of shallow groundwater mixing was evaluated based on multivariate statistics (e.g., M3 modeling). The relationship between fracture-filling minerals and groundwater chemistry also has been investigated through a reaction-path modeling. However, these previous studies in South Korea had been conducted without some important geochemical data including isotopes, oxidationreduction indicators and DOC, mainly due to the lack of available data. Therefore, a detailed geochemical investigation is required over the country to collect these hydrochemical data to select a geological disposal site based on scientific evidence.

• The Journal of Korean Society for Radiation Therapy
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• v.34
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• pp.51-60
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• 2022

Objectives: The purpose is to evaluate dosimetric performance and delivery efficiency of VMAT with Halcyon LINAC for double target spine SBRT Materials and Methods: 12 patients with spine oligometastases were retrospectively studied. Single-isocenter spine SBRT plans was established using Halcyon® with Dual Layer MLC and Truebeam® with High Definition MLC. All patients' plans were created in Eclipse TPS through the identical conditions and optimization. C.I, H.I, G.I (Gradient Index), maximal and volumetric doses to spinal cord and low dose area were evaluated for comparison of both plans. Also, total MU and BOT(Beam On Time) were evaluated. Results: Halcyon plans was no Statistical differences in C.I and H.I. However, the average of G.I was 4.64 for Halcyon, which decreased to 5.5% compared to Truebeam (P<0.001). Halcyon plans demonstrated statistically significant reduced G.I. The average of 50% and 25% isodose volume was 487.56 cc (-3.82%, P<0.001), 1859.45 cc (-4.75%, P<0.001) in Halcyon, respectively. Significantly reduced low dose spill were observed in Halcyon plans. In the evaluation of the spinal cord, the average of Dmean and V10 of Halcyon plans in the sample group with an overlap volume of less than 1 cc was 6.802 Gy (-3.504%, P=0.067), 5.766±1.683 cc (-8.199%, P=0.002), respectively. Halcyon plans demonstrated statistically significant reduced D_mean and V10. For delivery efficiency, MU and BOT(maximum dose rate for each machine), on average, increased in Halcyon plans. However, the average of BOT(800MU/min for each machine) was 648.33 sec for Halcyon (-1.74%, P<0.001). Conclusion: Halcyon plan for double-target spine SBRT demonstrated advantages in the low dose area with a steep dose gradient, while having dosimetrically equivalent target dose distribution and spinal cord protective effect. As a result, Halcyon LINAC produced a dosimetrically improved plan for double-target spine SBRT.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.5D
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• pp.885-894
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• 2006

The purpose of this study is focused on the development of the effective classification technique using ultra multiband of hyperspectral image. This study suggests the classification technique using canonical correlation analysis, one of multivariate statistical analysis in hyperspectral image classification. High accuracy of classification result is expected for this classification technique as the number of bands increase. This technique is compared with Maximum Likelihood Classification(MLC). The hyperspectral image is the EO1-hyperion image acquired on September 2, 2001, and the number of bands for the experiment were chosen at 30, considering the band scope except the thermal band of Landsat TM. We chose the comparing base map as Ground Truth Data. We evaluate the accuracy by comparing this base map with the classification result image and performing overlay analysis visually. The result showed us that in MLC's case, it can't classify except water, and in case of water, it only classifies big lakes. But Canonical Correlation Classification (CCC) classifies the golf lawn exactly, and it classifies the highway line in the urban area well. In case of water, the ponds that are in golf ground area, the ponds in university, and pools are also classified well. As a result, although the training areas are selected without any trial and error, it was possible to get the exact classification result. Also, the ability to distinguish golf lawn from other vegetations in classification classes, and the ability to classify water was better than MLC technique. Conclusively, this CCC technique for hyperspectral image will be very useful for estimating harvest and detecting surface water. In advance, it will do an important role in the construction of GIS database using the spectral high resolution image, hyperspectral data.

• Korean Journal of Psychosomatic Medicine
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• v.31 no.2
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• pp.165-172
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• 2023

Objectives : The purpose of this study is to determine whether there is a significant difference in the neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio according to the history of suicide attempt in patients with psychiatric diseases. Methods : A medical record review was conducted on patients who had been hospitalized in Konyang University Hospital since 2021-03-01 to 2023-02-28 to collect demographic and clinical characteristics. T-test for continuous variables and Chi-square test for categorical variables were performed to determine demographic differences according to the history of suicide attempt, and the ANCOVA test was performed to compare the average value of peripheral inflammatory marker according to the history of suicide attempt with gender and age as covariates. One-way variance analysis was performed to determine whether the number of suicide attempt causes significant difference of the peripheral inflammatory marker. Results : The final analysis target of this study was 266 patients, 101 had history of suicide attempt, and 165 had no history of suicide attempt. The neutrophil-to-lymphocyte ratio (p<0.001) and platelet-to-lymphocyte ratio (p<0.001) were higher in patients with the history of suicide attempt than patients without the history of suicide attempt, but the neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio were not significantly increased depending on the serial increase of number of suicide attempts. Conclusions : This study suggests that peripheral inflammatory markers are meaningful and easily accessible indicators for predicting the risk of suicide attempt in psychiatric patients. We expect that prospective follow-up study will be conducted with more subjects and controlled potential confounding variables.

• Journal of Life Science
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• v.33 no.12
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• pp.1036-1045
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• 2023

Sarcopenia, a condition characterized by the insidious loss of skeletal muscle mass and strength, represents a significant and growing healthcare challenge, impacting the mobility and quality of life of aging populations worldwide. This study investigated the therapeutic potential of soybean leaf extract (SL) for dexamethasone (Dexa)-induced muscle atrophy in vitro and in an in vivo model. In vitro experiments showed that SL significantly alleviated Dexa-induced atrophy in C2C12 myotube cells, as evidenced by preserved myotube morphology, density, and size. Moreover, SL treatment significantly reduced the mRNA and protein levels of muscle RING-finger protein-1 (MuRF1) and muscle atrophy F-box (MAFbx), key factors regulating muscle atrophy. In a Dexa-induced atrophy mouse model, SL administration significantly inhibited Dexa-induced weight loss and muscle wasting, preserving the mass of the gastrocnemius and tibialis anterior muscles. Furthermore, mice treated with SL exhibited significant improvements in muscle function compared to their counterparts suffering from Dexa-induced muscle atrophy, as evidenced by a notable increase in grip strength and extended endurance on treadmill tests. Moreover, SL suppressed the expression of muscle atrophy-related proteins in skeletal muscle, highlighting its protective role against Dexa-induced muscle atrophy. These results suggest that SL has potential as a natural treatment for muscle-wasting conditions, such as sarcopenia.

• Korean Journal of Culture and Social Issue
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• v.9 no.1
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• pp.115-137
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• 2003

This study aims to investigate the related variables of self-esteem and depression among the Korean elderly people living alone and examine the relationships or interactions between those variables. Participants were 676 elderly men and women who were at least 65 years of age(M=76.17, sd=7.60) and lived in Seoul, Korea. Three hundred seventy eight participants of this study were living alone. Participants completed questionnaires and psychological tests including: Rosenberg's Self-Esteem Scale, Zung's Self-Rating Depression Scale, The Index of Activities of Daily Living(IADL), Social Support Index(SSI), and Life Satisfaction in the Elderly Scale(LSES). Main statistical designs were 2(gender)×2(residential types), Pearson-product moment and regression analysis. Results indicated that the elderly living alone recognized their health poorer, have lower economic status, and received less social supports than the elderly lived with others. The elderly men who had children were more likely to lived alone. And the elderly men living alone received less social supports than the elderly women living alone, and significant gender difference was found in the reason of living alone. The elderly men living alone had lower self-esteem than the elderly women living alone, while the elderly living alone showed more depressive symptoms than the elderly living with others. There were 2-way interactions both in self-esteem and depression by gender and residential types. There was highly significant gender difference in self-esteem only for the elderly living alone, and it was found that there was no significant difference in depression between elderly men living alone and women living with others. Regression analysis revealed that physical function and self-reported health are predictors of self-esteem, and physical function, self-reported health, and social support are predictors of depression for the Korean elderly living alone. These findings reiterate the role of physical function, social support, health in self-esteem and depession among the elderly and suggest the gender role for quality of life among the Korean elderly living alone.

• Health Policy and Management
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• v.34 no.1
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• pp.48-58
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• 2024

Background: The purpose of this study was to investigate the association between external medical service use and the characteristics of Chungcheongnam-do patients. We aimed to provide evidence of external medical service use enhance the healthcare delivery system in Chungcheongnam-do. Methods: We used the Health Insurance Cohort DB 2.0 of 2016-2019, and 2,570,439 patients were included in the study. Multivariate logistic regression and multinomial logistic regression were used to identify the association between external medical service use and each patient characteristic. Generalized linear model was used to identify the association between medical costs and external medical service use area. Results: During the study period, 32.2% of inpatients and 12.5% of outpatients had external medical service use in Chungcheongnam-do. In comparison to patients living in Cheonan and Asan, the odds ratio (OR) for external medical services use was higher across all regions. Specifically, hospitalized patients from Gyeryong, Nonsan, and Geumsan (OR, 116.817) and Gongju, Buyeo, and Cheongyang (OR, 72.931) demonstrated extremely high likelihood of external medical service use in the Daejeon area. Furthermore, compared to medical expenses incurred within Chungcheongnam-do, patients with external medical service use in the capitol area (outpatient=17.01%, inpatients=22.11%) and Daejeon area (outpatient=16.63%, inpatients=15.41%) spent more on healthcare services. Conclusion: This study found the evidence of external medical service use among Chungcheongnam-do patients. Further study should be conducted taking into account variables including satisfaction of local medical services, different types of patient diseases, and others. The study's findings may serve as a foundation for policy proposals aimed at ensuring the financial stability of our health insurance system, ensuring the efficient delivery of medical care, and localization of medical care.

• Journal of The Korean Association For Science Education
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• v.29 no.2
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• pp.137-155
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• 2009

The purpose of the present study was to analyse the effectiveness of a gifted education program. To analyse the effectiveness of an education program for the gifted affiliated with a university, the study carried out a quasi-experimental design to compare the 153 gifted students who enrolled in an education center for the gifted and the 131 potentially gifted students who were nominated by teachers for their high achievements and interests in science but without any education services for the gifted. These two groups of students were compared in the aspects of problem finding ability in science, motivation, self regulation, science-related attitudes, and science anxiety through the pre- and post-treatment settings. The results indicated that the gifted group showed a significant improvement in originality and elaboration of problem-finding ability, but the potentially gifted group showed significant decrease in most variables of problem finding. Related to motivation and self-regulated learning, gifted students showed an increase in cognitive strategy use and decrease in intrinsic value, but the potentially gifted students showed significant decreases in most variables related to motivation and self-regulation, except intrinsic value. Related to the scientific attitudes and science anxiety, there were no significant changes between pre- and post-tests in the gifted group, but significant decreases in most variables were found in the potentially gifted group. The results of paired t-test and Ancova indicate that significant differences between the gifted and the potentially gifted groups are mainly due to the significantly lowered performance in post tests in the potentially gifted group, rather than a significant increase in gifted group.

• Food Science and Preservation
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• v.30 no.5
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• pp.822-832
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• 2023

This study investigates the effectiveness of CA (controlled atmosphere) containers in maintaining the freshness of exported melons. The melons were harvested on June 5, 2023, in the Yeongam area of Jeollanam-do, Korea. The CA container was loaded with melon samples packed in an export box. The temperature inside the container was set at 4℃, while the gas composition was set at 5% oxygen, 12% carbon dioxide, and 83% nintrogen. Following two weeks of simulated transportation, quality analysis was conducted at 10℃. The melons were inoculated with spore suspensions, and the decay rate was determined to investigate the effect of the gas composition inside the CA container on suppressing the occurrence of Penicillium oxalicum in melons. The results were compared with a Reefer container set at the same temperature. The samples transported in the CA container exhibited lower weight loss. The melon pulp softening, respiration rate, and ethylene production were slower using the CA container. Moreover, the decay rate during the distribution period in the CA container was lower than in the Reefer container. In contrast, the firmness of melons transported in the Reefer container decreased significantly (from 9.03N to 5.18N) immediately after transportation. The soluble solid content (SSC) of melons transported in the Reefer container also decreased rapidly. The results suggested that the CA container is the optimal export container for maintaining the freshness of melons.

• Journal of Korean Dental Hygiene Science
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• v.6 no.2
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• pp.115-127
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• 2023

Background: This study was conducted to determine the level of job satisfaction and patient safety cultural activities for dental hygienists and to determine the relationship between job satisfaction and patient safety cultural activities. Methods: A survey was conducted on 214 dental hygienists, and data from the final 180 were analyzed. Job satisfaction consisted of a total of 20 questions, and patient safety cultural activities included a total of 25 questions. The survey was conducted on a 5-point scale. Results: The average job satisfaction score of the study subjects was 3.44 points. Among patient safety cultural activities, infection control had the highest average score (4.12 points) and radiation safety management had the lowest average score (3.10 points). Patients with less than 3 years of clinical experience (4.01 points) had higher patient safety culture activity scores than those with 3 to 10 years of clinical experience (3.72 points) and those with more than 10 years of clinical experience (3.69 points). The level of patient safety cultural activities was statistically significantly higher as age, less clinical experience, and job satisfaction increased (p<0.05). Conclusion: In the case of dental hygienists, patient safety cultural activities must be carried out throughout the entire work, so an active will to practice patient safety cultural activities is necessary. In order to improve the performance of patient safety cultural activities, it is necessary to adjust the workload of dental hygienists to improve job satisfaction and create a work environment in which they can focus on patient safety cultural activities.