• Journal of radiological science and technology
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• v.45 no.5
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• pp.449-455
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• 2022

This study is to present a Geant4 code for the simulation of the absorbed dose distribution given by a medical linac for 6 MV photon beam. The dose distribution was verified by comparison with calculated beam data and beam data measured in water phantom. They were performed for percentage depth dose(PDD) and beam profile of cross-plane for two field sizes of 10 × 10 and 15 × 15 cm². Deviations of a percentage and distance were obtained. In energy spectrum, the mean energy was 1.69 MeV. Results were in agreement with PDD and beam profile of the phantom with a tolerance limit. The differences in the central beam axis data 𝜹₁ for PDD had been less than 2% and in the build up region, these differences increased up to 4.40% for 10 cm square field. The maximum differences of 𝜹₂ for beam profile were calculated with a result of 4.35% and 5.32% for 10 cm, 15 cm square fields, respectively. It can be observed that the difference was below 4% in 𝜹₃ and 𝜹₄. For two field sizes of 𝜹_50-90 and RW₅₀, the results agreed to within 2 mm. The results of the t-test showed that no statistically significant differences were found between the data for PDD of 𝜹₁, p>0.05. A significant difference on PDD was observed for field sizes of 10 × 10 cm², p=0.041. No significant differences were found in the beam profile of 𝜹₃, 𝜹₄, RW₅₀, and 𝜹_50-90. Significant differences on beam profile of 𝜹₂ were observed for field sizes of 10 × 10 cm², p=0.025 and for 15 × 15 cm², p=0.037. This work described the development and reproducibility of Geant4 code for verification of dose distribution.

• Journal of the Korean Society of Radiology
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• v.16 no.5
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• pp.611-618
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• 2022

The purpose of this study was to confirm the degree of other behaviors among university students in the department of radiology(science) who experienced online classes in the COVID-19 situation and to investigate the effect of self-directed learning ability, flow and academic achievement on other behaviors. The research method was descriptive research. Data were 200 students collected from June 1 to 30 in 2022 using structured questionnaires as students in the Department of Radiology(science). Collected data were analyzed using descriptive statistics, t-test, ANOVA, Cronbach's pearson's correlation, multiple regression analysis with SPSS/WIN 21.0. The result of the study showed that the other behaviors were in the order of 'having s different thought, and 'sending text messages'. other behaviors was 1.75, self-directed learning ability was 3.60, flow was 3.23 and academic achievement was 4.29. There was a significant negative correlation between other behaviors and self-directed learning ability, flow, academic achievement. Factors influencing other behaviors were academic achievement, age, flow, self-directed learning ability in that order. As a result of the above research. it is expected that specific measures and various teaching methods to be flowed in the class are need as the way to lower the other behaviors of university students in the Department of Radiology(science) is to increase academic achievement.

• Journal of Chest Surgery
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• v.54 no.6
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• pp.480-486
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• 2021

Background: Although various methods are already used to calculate predicted postoperative forced expiratory volume in 1 second (FEV₁) based on preoperative FEV₁ in lung surgery, the predicted postoperative FEV₁ is not always the same as the actual postoperative FEV₁. Observed postoperative FEV₁ values are usually the same or higher than the predicted postoperative FEV₁. To overcome this issue, we investigated the relationship between the number of resected lung segments and the discordance of preoperative and postoperative FEV₁ values. Methods: From September 2014 to May 2020, the data of all patients who underwent anatomical lung resection by video-assisted thoracoscopic surgery (VATS) were gathered and analyzed retrospectively. We investigated the association between the number of resected segments and the differential FEV₁ (a measure of the discrepancy between the predicted and observed postoperative FEV₁) using the t-test and linear regression. Results: Information on 238 patients who underwent VATS anatomical lung resection at Kyung Hee University Hospital at Gangdong and by DH. Kim for benign and malignant disease was collected. After applying the exclusion criteria, 114 patients were included in the final analysis. In the multiple linear regression model, the number of resected segments showed a positive correlation with the differential FEV₁ (Pearson r=0.384, p<0.001). After adjusting for multiple covariates, the differential FEV₁ increased by 0.048 (95% confidence interval, 0.023-0.073) with an increasing number of resected lung segments (R²=0.271, p<0.001). Conclusion: In this study, after pulmonary resection, the number of resected segments showed a positive correlation with the differential FEV₁.

• Journal of The Korean Society of Integrative Medicine
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• v.10 no.1
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• pp.137-147
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• 2022

Purpose : The purpose of this study is to investigate how the existence of companion animals and the type of companion animals affect the quality of life and emotional stability of adults in their 20s. Methods : The subjects of this study were adults in their twenties living in Busan who could understand the method of this study. The survey method was conducted with a questionnaire, consisting of 4 questions on general characteristics, 26 questions on quality of life, and 20 questions on emotional stability for a total of 50 questions. An independent t-test and one-way ANOVA were used to verify the difference in quality of life and emotional stability according to general characteristics. Results : As a result of analyzing the difference in the quality of life of the study subjects, the case of having a companion animal scored statistically significantly higher in the satisfaction of the physical domain, psychological domain, living environment domain, overall quality of life domain, and social domain. In addition, there was a statistically significant difference in the case of companion animals according to the type of companion animal. However, there was no statistical significance in the analysis of differences in emotional stability of study subjects according to the presence or absence of companion animals. Conclusion : This study was conducted with 400 adults in their twenties to determine the effects of the presence and absence and type of companion animals on the quality of life and emotional stability of adults in their twenties. As a result, the group with companion animals showed higher satisfaction scores than the group without companion animals in terms of quality of life. This suggests that raising companion animals for adults in their 20s has a positive effect on improving their quality of life. Therefore, it can be recommended for the physical, psychological, and social health of adults in their 20s.

• Korean Journal of Clinical Laboratory Science
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• v.55 no.1
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• pp.9-15
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• 2023

The purpose of this study was to analyze the relationship between diabetes and liver function test results. Unlike type 2 diabetes mellitus (T2DM), hepatogenous diabetes is caused by abnormal liver function. In this study, the relationship between liver enzymes, aspartate aminotransferase (AST), alanine transaminase (ALT), and the AST/ALT ratio (De Ritis ratio), indicating liver function, and diabetes-related tests was analyzed. The results of the study showed a positive correlation between AST and glucose (r=0.14, P<0.01), ALT and glucose (r=0.21, P<0.01), AST and glycated hemoglobin (HbA1c) (r=0.15, P<0.01), and ALT and HbA1c (r=0.20, P<0.01). The De Ritis ratio showed a negative correlation with glucose (r=-0.20, P<0.01) and HbA1c (r=-0.14, P<0.01). The results of regression analysis with AST, ALT, and the De Ritis ratio as independent variables and glucose (R²=0.05) and HbA1c (R²=0.04) as dependent variables revealed that the independent variables had a statistically significant effect on the dependent variables. AST showed a lower correlation between blood glucose and glycated hemoglobin than ALT, and an increase in ALT caused a decrease in the De Ritis ratio. Therefore, the De Ritis ratio can be said to be meaningful in relation to diabetes-related tests.

• Journal of Korea Society of Industrial Information Systems
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• v.15 no.1
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• pp.59-72
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• 2010

Competition among enterprises has been more intensified as one among supply chains in the rapidly changing environment. This study investigated the influence of the supply chain integration factors, such as integration of functions inside an enterprise, integration of suppliers, and integration of customers, on the internal and external visibility, and non-financial and financial performances of enterprises. To test these relationships, the survey was conducted on suppliers, manufacturers, and distributors in Korea which have been implementing SCM. Eighty-one questionnaires were collected and used for this study. The study results using the covariance structure analysis are showed as follows. First, the integration of suppliers had a significant influence on both the internal and the external visibility of enterprises, while the integration of functions inside an enterprise had a significant impact on only the internal visibility of enterprises, and the integration of customers on only the external visibility. Second, the internal and external visibility of enterprises had significant impacts on non-financial performance of enterprises. However, the internal and external visibility of enterprises didn't give any direct or indirect influence on the financial performance of enterprises. Third, the non-financial performance of enterprises had a significant impact on financial performance of enterprises.

• Journal of Korea Entertainment Industry Association
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• v.13 no.4
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• pp.377-384
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• 2019

This study was intended to understand the status of dysphagia related knowledge, attitude and nursing performance of nursing staff's in geriatric hospitals, to confirm the correlation among these, and to provide basic resources for dysphagia nursing intervention programs. The 220 subjects were nursing staff's who worked in geriatric hospitals located in G city and N city. For data analysis, The descriptive statistic was used to analyze the subjects' general characteristics, and dysphagia related characteristics, knowledge, attitude and nursing performance degree. For the differences of dysphagia related knowledge, attitude and nursing performance according to the subjects' general characteristics, t-test and ANOVA were used. The correlation of the subjects' knowledge, attitude and nursing performance degree was analyzed with Pearson's correlation coefficient. The score of the subjects' dysphagia related knowledge was average 14.07±2.94, the subjects' dysphagia related attitude was average 3.59±0.39, the subjects' dysphagia nursing performance was 3.10±0.43. dysphagia nursing performance had a significantly positive correlation with dysphagia related knowledge(r=0.295, p=.000) and dysphagia related attitude(r=0.392, p=.000). The above result of the study indicated positive attitude based on accurate knowledge is needed for nursing staff's in geriatric hospitals to improve nursing performance for dysphagia. When education programs for dysphagia are planned in geriatric hospitals, it is necessary to consider knowledge level and attitude simultaneously.

• Journal of the Korean Geotechnical Society
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• v.22 no.6
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• pp.27-40
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• 2006

Damage of cut-and-cover tunnel lining can be attributed to physical and mechanical factors. Physical factors include material property, reinforcement corrosion, etc. while mechanical factors include underground water pressure, vehicle loads, etc. This study is limited to the modeling of rigid circular cut and cover tunnel constructed at a depth of $1.0{\sim}1.5D$ in loose sandy ground and subjected to a vibration frequency of 100 Hz. In this study, only damages due to mechanical factors in the form of additional loads were considered. Among the different types of additional, excessive earth pressure acting on the cut-and-cover tunnel lining is considered as one of the major factors that induce deformation and damage of tunnels after the construction is completed. Excessive earth pressure may be attributed to insufficient compaction, consolidation due to self-weight of backfill soil, precipitation and vibration caused by traffic. Laboratory tunnel model tests were performed in order to determine the earth pressure acting on the tunnel lining and to investigate the applicability of existing earth pressure formulas. Based on the difference in the monitored and computed earth pressure, a factor of safety was recommended. Soil deformation mechanism around the tunnel was also presented using the picture analysis method.

• Journal of the Korean Geotechnical Society
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• v.22 no.6
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• pp.15-26
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• 2006

Although numerous investigations have been performed over the years to predict the behavior and bearing capacity of piles, the mechanisms are not yet entirely understood. The prediction of bearing capacity is a difficult task, because large numbers of factors affect the capacity and also have complex relationship one another. Therefore, it is extremely difficult to search the essential factors among many factors, which are related with ground condition, pile type, driving condition and others, and then appropriately consider complicated relationship among the searched factors. The present paper describes the application of Artificial Neural Network (ANN) in predicting the capacity including its components at the tip and along the shaft from dynamic load test of the driven piles. Firstly, the effect of each factor on the value of bearing capacity is investigated on the basis of sensitivity analysis using ANN modeling. Secondly, the authors use the design methodology composed of ANN and genetic algorithm (GA) to find optimal neural network model to predict the bearing capacity. The authors allow this methodology to find the appropriate combination of input parameters, the number of hidden units and the transfer structure among the input, the hidden and the out layers. The results of this study indicate that the neural network model serves as a reliable and simple predictive tool for the bearing capacity of driven piles.

• The Journal of Korean Obstetrics and Gynecology
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• v.22 no.4
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• pp.122-134
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• 2009

Purpose: The purpose of this study is to know the blood stasis pattern for the patients who had hysterectomy. Methods: Among the patients who had hysterectomy in the department of obstetrics and gynecology, OO medical center from March 3rd 2009 to October 21st 2009, subjects who met inclusion criteria and submitted appropriate questionnaire. We compared blood stasis score and operational method, age, BMI, past operation history of abdominal and pelvic site, parity, whether adhesiolysis, oriental medicine intervention was done. For statistics, we used independent samples t-test, oneway analysis of variances(ANOVA) and SPSS version 13.0 for windows. Results: Blood stasis score of the subtotal hysterectomy group ($44.43{\pm}15.01$) is higher than that of the total hysterectomy group($39.04{\pm}12.46$). Blood stasis score under the age 40($51.88{\pm}12.68$) is higher than 40-49 age patients($40.34{\pm}14.24$) and over the age 50 patients($41.62{\pm}13.46$). There is no statistically significant difference between laparoscopic and abdominal trial, whether adhesiolysis, oriental medicine intervention was done, BMI, past operation history abdominal and pelvic site, parity, chief complaint before hysterectomy, oriental medicine intervention. Conclusion: Through the results showed, when traditional Korean medical doctors use static blood medication, history of hysterectomy and age should be considered as the history of subtotal hysterectomy and younger age tend to have a higher rate of a blood stasis pattern. We need a further study to develop blood stasis indicators with a validated questionnaire, and more subjects involved at multiple institutions.