• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.6
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• pp.351-361
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• 2021

The seriousness of fire is rising because fire causes enormous damage to property and human life. Therefore, this study aims to predict various risk factors affecting fire by fire type. The predictive analysis of fire factors was carried out targeting Gyeonggi-do, which has the highest number of fires in the country. For the analysis, using machine learning methods SVM (Support Vector Machine), RF (Random Forest), GBRT (Gradient Boosted Regression Tree) the accuracy of each model was presented with a high fit model through MAE (Mean Absolute Error) and RMSE (Root Mean Squared Error), and based on this, predictive analysis of fire factors in Gyeonggi-do was conducted. In addition, using machine learning methods such as SVM (Support Vector Machine), RF (Random Forest), and GBRT (Gradient Boosted Regression Tree), the accuracy of each model was presented with a high-fit model through MAE and RMSE. Predictive analysis of occurrence factors was achieved. Based on this, as a result of comparative analysis of three machine learning methods, the RF method showed a MAE = 1.765 and RMSE = 1.876, as well as the MAE and RMSE verification and test data were very similar with a difference between MAE = 0.046 and RMSE = 0.04 showing the best predictive results. The results of this study are expected to be used as useful data for fire safety management allowing decision makers to identify the sequence of dangers related to the factors affecting the occurrence of fire.

• Journal of Industrial Convergence
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• v.21 no.7
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• pp.19-27
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• 2023

As the secondary battery market expands, the process of producing laterite ore using the rotary kiln and electric furnace method is expanding worldwide. As ESG management expands, the management of air pollutants such as nitrogen oxides in exhaust gases is strengthened. The rotary kiln, one of the main facilities of the pyrometallurgy process, is a facility for drying and preliminary reduction of ore, and it generate nitrogen oxides, thus prediction of nitrogen oxide is important. In this study, LSTM for regression prediction and LightGBM for classification prediction were used to predict and then model optimization was performed using AutoML. When applying LSTM, the predicted value after 5 minutes was 0.86, MAE 5.13ppm, and after 40 minutes, the predicted value was 0.38 and MAE 10.84ppm. As a result of applying LightGBM for classification prediction, the test accuracy rose from 0.75 after 5 minutes to 0.61 after 40 minutes, to a level that can be used for actual operation, and as a result of model optimization through AutoML, the accuracy of the prediction after 5 minutes improved from 0.75 to 0.80 and from 0.61 to 0.70. Through this study, nitrogen oxide prediction values can be applied to actual operations to contribute to compliance with air pollutant emission regulations and ESG management.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.43 no.4
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• pp.433-447
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• 2023

There is a growing demand for the stability of existing dams due to abnormal climate and the aging of dams. Emergency Action Plans (EAPs) for reservoir or dam failure only consider a single rainfall event. Therefore, this study simulates dam failure caused by continuous rainfall events, and proposes the establishment of EAP by selecting the optimal shelters. We define a mega rainfall event scenario caused by continuous rainfall events with 500-year frequency in the Chungju Dam watershed and estimate the mega flood. The mega flood event scenario is divided into two cases: scenario A represents the flooding case caused by discharge release from a dam, while scenario B is the case of a dam break. As a result of flood inundation analysis, the flooded damage area by the scenario A is 50.06 km² and the area by the scenario B is 6.1 times of scenario A (307.45 km²). We select optimal shelters for each administrative region in the city of Chungju, which has the highest inundation rate in the urban area. Seven shelter evaluation indicators from domestic and foreign shelter selection criteria are chosen, and Analytical Hierarchy Process (AHP) method is used to evaluate the alternatives. As a result of the optimal shelter selection, the six shelters are selected and five are schools. This study considers continuous rainfall events for inundation analysis and selection of optimal shelters. Also, the results of this study could be used as a reference for establishment of the EAP.

• Journal of the Korean Association of Geographic Information Studies
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• v.27 no.1
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• pp.52-66
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• 2024

The purpose of this study is to identify the spatial system and characteristics of the urban center by deriving the boundaries of the urban center set in the urban basic plan for Busan Metropolitan City and diagnosing the role and status of the center. To this end, four indicators representing the characteristics of the center were selected through a review of previous studies, and the boundaries of the center were derived using spatial statistical techniques with strengths in geographical boundary analysis. Then, using the indicators of center characteristics and population potential functions, we diagnosed the influence and potential of each center in the spatial structure of Busan Metropolitan City. The analysis showed that the scale of the centers varies greatly, and the unutilized areas where commercial areas are not activated and the expansion areas that spread beyond commercial areas to residential and industrial areas are different for each urban center. The results of the potential measurement, which indicates the attractiveness of the center, also showed areas with strong and weak population potential. Therefore, systematic management and strategies based on the hierarchical characteristics and influence measurement results are needed to strengthen the function of urban centers. The results analyzed in this study can be used as a resource for responding to various urban planning needs and policy changes in the future, along with station area development plans and spatial innovation zones for building a sustainable urban growth system, balanced development, and strengthening the function of centers.

• Economic and Environmental Geology
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• v.57 no.4
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• pp.353-362
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• 2024

This study examined the spectral characteristics of sediments according to moisture content using an unmanned aerial vehicle (UAV)-based hyperspectral sensor and evaluated the efficiency of moisture content detection at different flight altitudes. For this purpose, hyperspectral images in the 400-1000nm wavelength range were acquired and analyzed at altitudes of 40m and 80m for sediment samples with various moisture contents. The reflectance of the sediments generally showed a decreasing trend as the moisture content increased. Correlation analysis between moisture content and reflectance showed a strong negative correlation (r < -0.8) across the entire 400-900nm range. The moisture content detection model constructed using the Random Forest technique showed detection accuracies of RMSE 2.6%, R² 0.92 at 40m altitude and RMSE 2.2%, R² 0.95 at 80m altitude, confirming that the difference in accuracy between altitudes was minimal. Variable importance analysis revealed that the 600-700nm band played a crucial role in moisture content detection. This study is expected to be utilized in efficient sediment moisture management and natural disaster prediction in the field of environmental monitoring in the future.

• Korean Journal of Construction Engineering and Management
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• v.25 no.2
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• pp.23-35
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• 2024

This study analyzed the correlation between each of the 12 influencing factors in FAR 16.04 and the decision-making process for construction contract types, using data from a total of 2,406 DoD Construction Acquisitions spanning from 2008 to 2022. The study considered 12 independent variables, grouped into 4 Characteristics with 3 factors each. Meanwhile, all other contract types were categorized into two types: Firm-Fixed-Price (FFP) and Cost-Reimbursement Contract (CRC), which served as the dependent variables. The findings revealed that FFP contracts significantly dominated in terms of acquisition volume. In line with prevailing beliefs, logistic data analysis and Analytical Hierarchy Process (AHP) analysis of Relative Weights from Experts' Survey demonstrated that independent variables like Uncertainty of the Scope of Work and Complexity found out to be increasing the likelihood of selecting CRC. The number of contractors in the market does indeed influence the possibilities of contract decision-making between CRC and FFP. Meanwhile, the p-values of the top 3 influencing factors on CRC from the AHP analysis-namely, Appropriateness of CAS, Project Urgency, and Cost Analysis-exceeded 0.05 in the binominal regression results, rendering it inconclusive whether they significantly influenced the construction contract type decision, particularly with respect to payment methods. This outcome partly results from the fact that a majority of respondents possessed specific experiences related to the USFK relocation project. Furthermore, influencing factors in construction projects behave differently than common beliefs suggest. As a result, it is imperative to consider the 12 influencing factors categorized into 4 Characteristics areas before establishing acquisition strategies for targeted construction projects.

• Journal of Chest Surgery
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• v.39 no.12 s.269
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• pp.920-926
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• 2006

Background: Mortality and morbidity of anastomotic complications after esophagectomy have gradually decreased in recent years. However, swallowing difficulties and reflux symptoms after esophagogastrostomy continue to be a burden jeopardizing the quality of life. In the present study, we evaluated the quality of esophagogastrostomy by analyzing anastomotic stenosis and reflux esophagitis. Material and Method: A retrospective analysis was made in 74 patients who underwent esophagogastrostomy after esophagectomy by one surgeon between January 1995 and December 2004. 53 patients of them received endoscopic examination during follow-up($29{\pm}23.6$ months, range $5{\sim}111$ months). Reflux esophagitis and stenosis at anastomostic site were analyzed according to the techniques and locations of esophagogastrostomy. Result: The median age at the time of repair was $60.3{\pm}8.87$ years(range $39{\sim}81$ years). 23 patients received a hand-sewn esophagogastric anastomosis and 30 patients a circular stapled one. There was no significant statistical difference in terms of anastomotic stenosis(p=0.64) and reflux esophagitis(p=0.41) between the two groups. Cervical anastomosis was peformed in 26 patients and intrathoracic anastomosis in 27 patients. No significant statistical difference in anastomotic stenosis between the two groups was found(p=0.44), but reflux esophagitis was noted in 3 patients in the cervical anastomosis group and 14 patients in the intrathoracic anastomosis group(p=0.003). Conclusion: Cervical anastomosis was supposed to have a better quality of esophagogastrostomy by lowering the risk of reflux esophagitis. In the future, the comprehensive study including a patient's subjective symptom and Barrett's metaplasia should be performed in larger cases.

• Journal of Korean Home Economics Education Association
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• v.30 no.1
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• pp.99-114
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• 2018

Textbooks are one of the most crucial variables that determine the quality of education and one of the most influential sources for education. Textbooks should be designed with inquiring tendencies so as to help students to practice self-directed learning. inquiring textbooks can not only intrigue students but also enhance the quality of class. Here, this author is going to analyze the inquiring tendencies of a core construct, 'management', in 12 different types of high school Technology & Home Economics textbooks reflecting the 2015 revised national curriculum based on the Romey method. According to the analysis results, only one type of textbook shows inquiring tendencies in the text, which means that the text is more oriented to delivering knowledge rather than to pursuing students' inquiry learning. Because analysis indexes for figures and diagrams fall under the range of desirable inquiring tendencies in 10 types of textbooks, the figures and diagrams presented in Home Economics textbooks are intended to induce particular learning activity. Learning activity indexes reveal 9 types of textbooks' inquiring tendencies, which means that Home Economics textbooks present a reasonable amount of learning activity in general in order to intrigue students and stimulate their inquiring mind. In terms of evaluation indexes, only 2 types of textbooks show inquiring tendencies. According to the results of examining each individual textbook, some of the Home Economics textbooks reflecting the 2015 revised national curriculum include inquiring elements in the text, figures and diagrams, activities, and evaluation all; however, some still need improvements. Regarding how to better the Home Economics textbooks, this researcher will suggest the following implications and complements. Home Economics textbooks should include inquiring elements to induce interactions properly in the class, and when they write the textbooks, the text, figures and diagrams, activities, and evaluation should be designed balancedly, and the questions need to be expressed in a way to develop students' inquiring mind.

• 대한공업교육학회지
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• v.39 no.1
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• pp.23-46
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• 2014

The purpose of this study was to analyze the textbooks of career counseling which are written or translated in Korean so as to understand the usefulness and limitation on the usage of career counseling textbooks. Research questions are as follows: 1) what contents are included in textbooks of career counseling? 2) what are the differences of content rates among textbooks of career counseling? 10 textbooks of career counseling were analysed(6 textbooks: introduction to career counseling, 4 textbooks: focused on career counseling skills and techniques) based on the competency components for career counseling professionals presented by Yoo(2009). Results indicated that 1) 6 textbooks of introduction to career counseling have the most content of 'category1: theories and concepts related to career counseling'. In comparison, 4 textbooks focused on career counseling skills and techniques have the most content of 'category4: career counseling competency'. 2) Based on the unit of analysis chapter, the highest rates are 'category4: career counseling competency(33.33%)' and 'category1: theories and concepts related to career counseling(28.15%)'. 3) It is hard to find the contents related to the knowledge and skills of individual and group counseling(category 2), the competencies of network, problem solving, peer counselor feedback, administration, ethic(category 8,9,10,11,13), the growth and self-management as professionals(category 12,14).

• Progress in Medical Physics
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• v.26 no.3
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• pp.168-177
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• 2015

For evaluating the treatment planning accurately, the quality assurance for treatment planning is recommended when patients were treated with IMRT which is complex and delicate. To realize this purpose, treatment plan quality assurance software can be used to verify the delivered dose accurately before and after of treatment. The purpose of this study is to evaluate the accuracy of treatment plan quality assurance software for each IMRT plan according to MLC DLG (dosimetric leaf gap). Novalis Tx with a built-in HD120 MLC was used in this study to acquire the MLC dynalog file be imported in MobiusFx. To establish IMRT plan, Eclipse RTP system was used and target and organ structures (multi-target, mock prostate, mock head/neck, C-shape case) were contoured in I'mRT phantom. To verify the difference of dose distribution according to DLG, MLC dynalog files were imported to MobiusFx software and changed the DLG (0.5, 0.7, 1.0, 1.3, 1.6 mm) values in MobiusFx. For evaluation dose, dose distribution was evaluated by using 3D gamma index for the gamma criteria 3% and distance to agreement 3 mm, and the point dose was acquired by using the CC13 ionization chamber in isocenter of I'mRT phantom. In the result for point dose, the mock head/neck and multi-target had difference about 4% and 3% in DLG 0.5 and 0.7 mm respectively, and the other DLGs had difference less than 3%. The gamma index passing-rate of mock head/neck were below 81% for PTV and cord, and multi-target were below 30% for center and superior target in DLGs 0.5, 0.7 mm, however, inferior target of multi-target case and parotid of mock head/neck case had 100.0% passing rate in all DLGs. The point dose of mock prostate showed difference below 3.0% in all DLGs, however, the passing rate of PTV were below 95% in 0.5, 0.7 mm DLGs, and the other DLGs were above 98%. The rectum and bladder had 100.0% passing rate in all DLGs. As the difference of point dose in C-shape were 3~9% except for 1.3 mm DLG, the passing rate of PTV in 1.0 1.3 mm were 96.7, 93.0% respectively. However, passing rate of the other DLGs were below 86% and core was 100.0% passing rate in all DLGs. In this study, we verified that the accuracy of treatment planning QA system can be affected by DLG values. For precise quality assurance for treatment technique using the MLC motion like IMRT and VMAT, we should use appropriate DLG value in linear accelerator and RTP system.