• Journal of The Korean Society of Agricultural Engineers
• /
• v.61 no.1
• /
• pp.45-59
• /
• 2019

Since the baseflow, which constitutes most of the river flow in the dry season, plays an important role in the solution of river runoff and drought, it is important to accurately evaluate the characteristics of the baseflow for river management. In this study, land use change was evaluated through time series data of land use, and then baseflow characteristics were analyzed by considering climate change and land use change using climate change scenarios. The results showed that the contribution of baseflow of scenarios considering both climate change and land use change was lower than that of scenarios considering only climate change for yearly and seasonal analysis. This implies that land use changes as well as climate changes affect base runoff. Thus, if we study the watershed in which the land use is occurring rapidly in the future, it is considered that the study should be carried out considering both land use change and climate change. The results of this study can be used as basic data for studying the baseflow characteristics in the Gapcheon watershed considering various land use changes and climate change in the future.

• Journal of Korean Society on Water Environment
• /
• v.27 no.4
• /
• pp.405-412
• /
• 2011

Increased Non-permeable areas which have resulted from civilization reduce the volume of groundwater infiltration that is one of the important factors causing water shortage during a dry season. Thus, seeking the efficient method to analyze the volume of groundwater in accurate should be needed to solve water shortage problems. In this study, two different watersheds were selected and precipitation, soil group, and land use were surveyed in a particular year in order to figure out the accuracy of estimated infiltration recharge ratio compared to Web-based Hydrograph Analysis Tool (WHAT). The volume of groundwater was estimated considering Antecedent soil Moisture Condition (AMC) and Curve Number (CN) using Long Term Hydrologic Impact Assessment (L-THIA) model. The results of this study showed that in the case of Kyoung-an watershed, the volume of both infiltration and baseflow seperated from WHAT was 46.99% in 2006 and 33.68% in 2007 each and in Do-am watershed the volume of both infiltration and baseflow was 33.48% in 2004 and 23.65% in 2005 respectively. L-THIA requires only simple data (i.e., land uses, soils, and precipitation) to simulate the accurate volume of groundwater. Therefore, with convenient way of L-THIA, researchers can manage watershed more effectively than doing it with other models. L-THIA has limitations that it neglects the contributions of snowfall to precipitation. So, to estimate more accurate assessment of the long term hydrological impacts including groundwater with L-THIA, further researches about snowfall data in winter should be considered.

• Journal of the Korean Geosynthetics Society
• /
• v.22 no.1
• /
• pp.67-74
• /
• 2023

In order to monitor the stability of slopes, research on data-based slope failure prediction and early warning is increasing. However, most papers overlook the quality of data. Poor data quality can cause problems such as false alarms. Therefore, this paper proposes a two-step hybrid approach consisting of rules and machine learning models for quality control of data collected from slopes. The rule-based has the advantage of high accuracy and intuitive interpretation, and the machine learning model has the advantage of being able to derive patterns that cannot be explicitly expressed. The hybrid approach was able to take both of these advantages. Through a case study, the performance of using the two methods alone and the case of using the hybrid approach was compared, and the hybrid method was judged to have high performance. Therefore, it is judged that using a hybrid method is more appropriate than using the two methods alone for data quality control.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.47 no.1
• /
• pp.41-50
• /
• 2024

Korea is facing a significant problem with historically low fertility rates, which is becoming a major social issue affecting the economy, labor force, and national security. This study analyzes the factors contributing to the regional gap in fertility rates and derives policy implications. The government and local authorities are implementing a range of policies to address the issue of low fertility. To establish an effective strategy, it is essential to identify the primary factors that contribute to regional disparities. This study identifies these factors and explores policy implications through machine learning and explainable artificial intelligence. The study also examines the influence of media and public opinion on childbirth in Korea by incorporating news and online community sentiment, as well as sentiment fear indices, as independent variables. To establish the relationship between regional fertility rates and factors, the study employs four machine learning models: multiple linear regression, XGBoost, Random Forest, and Support Vector Regression. Support Vector Regression, XGBoost, and Random Forest significantly outperform linear regression, highlighting the importance of machine learning models in explaining non-linear relationships with numerous variables. A factor analysis using SHAP is then conducted. The unemployment rate, Regional Gross Domestic Product per Capita, Women's Participation in Economic Activities, Number of Crimes Committed, Average Age of First Marriage, and Private Education Expenses significantly impact regional fertility rates. However, the degree of impact of the factors affecting fertility may vary by region, suggesting the need for policies tailored to the characteristics of each region, not just an overall ranking of factors.

• Journal of the Korea Society of Computer and Information
• /
• v.29 no.7
• /
• pp.209-219
• /
• 2024

In this paper, we propose a study to investigate the significant impact of digital technology on the development of the cultural industry and tourism. By collecting, selecting, and analyzing data on digital music products from 281 cities in China from 2005 to 2022, we confirm that well-known digital music products play a crucial role in promoting domestic tourism economic growth. However, their impact on the international tourism economy is not significant. Furthermore, these well-known digital music products can not only promote the development of the regional tourism economy but also influence the tourism economy of neighboring cities. The promotional effect of well-known digital music products is particularly important in fourth- and fifth-tier cities with rich cultural diversity and abundant tourism resources. Overall, well-known digital music products have a positive role in stimulating market vitality and promoting regional tourism economic development. These findings provide an important foundation for the integrated development of culture and tourism in the digital age and offer valuable insights for upgrading regional industrial structures and fostering regional harmonious development.

• The Korean Journal of Health Service Management
• /
• v.10 no.3
• /
• pp.1-12
• /
• 2016

Objectives : This study examined relations between investment efficiency and management performance as indexes related to productivity of Korean regional public hospitals. Methods : The analysis data are financial information of Korean regional public hospitals from 2011 to 2014. For the indicators, value added to total assets, value added to productive activity tangible fixed assets, and value added to personnel expenses, operating margin to revenues, net profit to total earnings, and ratio of value added. Results : Significant relevance was not shown among indicators of investment efficiency. However, Significant relevance was shown between value added to personnel expense and productivity per value added. Conclusions : It confirmed that outside support funds like subsidy did not have effect on improving the management performance. Also, it could be known that availability about input of capital and labor was not realized organically.

• 한국방재학회:학술대회논문집
• /
• 2007.02a
• /
• pp.579-582
• /
• 2007

In this paper, the inundation simulations were carried out by using GIS tools for the analysis of detention efficiency based on the results of runoff analysis according to location and scale of regional detention facilities. The inundation maps could be drawn by the inundation simulations, and the locations and magnitude of inundation areas could be estimated through the inundation maps. The inundation simulations with GIS tools are approved to be the one of the useful method in designing optimized location and scale of regional detention facilities.

• The Journal of Engineering Geology
• /
• v.2 no.2
• /
• pp.131-140
• /
• 1992

GIS(Geographic Information System) technology was applied for analysis of the potential degree of regional geologic hazard, especially landslide hazards in the suburb of Seoul City, whereby a regional geologic hazard map was produced. The factors causing a landslide such as slope geometry, geology, groundwater, soil property, rainfall and vegetation were incorporated through GIS in order to predict the potential hazards in this area. Cartographic simulation was finally made with these factors to produce a regional geologic hazard map. For this study, ARC/INFO and ERDAS systems were used in SUN 4-390 workstation.

• 한국경영정보학회:학술대회논문집
• /
• 2007.11a
• /
• pp.487-492
• /
• 2007

This research focuses on the development and empirical validation of a model of software piracy behavior on the basis of deterrence theory, expected utility theory and the theory of reasoned action. The total of sample numbered 86 and PLS (Partial Least Square) was utilized for analysis. The test of this study revealed that punishment severity was the greatest significant factor to influence to software piracy and subjective norms was also significantly related to it. However punishment certainty and software cost do not significantly affect to software piracy.

• Proceedings of the KSRS Conference
• /
• 2005.10a
• /
• pp.65-68
• /
• 2005

In order for effective disaster prevention, it is necessary to have some idea of when, where, why and what kind of weather disasters may occur, and how large they may be. But the regional characteristics of Shizuoka Prefecture from the viewpoint of weather disasters have not been studied before. In this study, the authors gathered the data which represent how many times weather disasters occurred in Shizuoka Prefecture in the last fourteen years, and then divided it into some regions using a multivariate analysis. The authors adopted principal component analysis on this data, and then adopted cluster analysis with principal component scores which must be significant in the previous analysis. Finally the authors set the regional division based on these clusters and described the regional characteristics. This study could contribute to the weather disaster prevention in Shizuoka Prefecture.