• Journal of the Korean Geotechnical Society
• /
• v.22 no.10
• /
• pp.93-100
• /
• 2006

The lateral soil movement in soft grounds undergoing improvement with application of vertical drains is analyzed on the basis of monitoring data at three fields, in which fifty six monitoring sites are located. Based on the investigations, the criterions are suggested to predict the lateral soil movement. In order to predict the lateral soil movement in the improved soft grounds by using the dimensionless parameter R suggested by Marche & Chapuis (1974), it is desirable that the maximum lateral displacement in the soft ground below the toe of embankment should be applied to calculate R instead of the lateral displacement at the toe of embankment. The lateral soil movement may increase rapidly, if the safety factor of slope is less than 1.4 in case of high ratio of H/B (Thickness of soft ground/Embankment width) such as 1.15 or is less than 1.2 in case of low ratio of H/B such as 0.05. Also, the graph suggested by Tschebotarioff (1973), which illustrates the relationship between the maximum height of embankments and the undrained shear strength of soft grounds, can be applied to the evaluation for the possibility of the lateral soil movement due to embankments on soft grounds.

• Korea Trade Review
• /
• v.41 no.5
• /
• pp.235-254
• /
• 2016

Recently, enterprise information management activities have been applied to promote electronic trade, while changing the paradigm of cross-border trade and overall trade business processes. L/C, which facilitates payment from the trade transaction in a company, has been able to eliminate the high cost and inefficient element of the trade process by utilizing the electronic letter of credit (e-L/C). This study examines the influential relationship among the e-trade utilizing factor (such as the perceived ease of use and the volition of CEO), the e-L/C and corporate performance, and the study aimed to verify the moderating effect of customer service level by organizations utilizing e-trade. For the purpose of the research, we conducted a survey implementing the e-L/C and analyzed the 338 data collected. The results of this research are as follows. First, the perceived ease of use and volition of CEO have positive impact on the e-L/C. Second, the e-L/C has positive impact on the business performance. Third, a moderating effect shows on the customer expectation level. The main implication of this study is that the perceived ease of use is to be considered preferentially than the volition of CEO in order to utilize electronic trading, and the volition of CEO shows synergy effect with customer service level by organization utilizing e-trade.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
• /
• v.6 no.12
• /
• pp.513-522
• /
• 2016

The importance of the national reseach and development project has been increased since the global financial crisis for overcoming the world economic recession and responding the threatens of the global competitiveness. As the budgets are increased and the size of the tasks is enormous, the government often requests high-level audits and data for the transparent management of research expenses. As a result, the researchers who have to concentrate on the original research work spend much time in administrative processing, government audit, and responding to the demand data than the time to concentrate on the research work. It is absolutely necessary to have a system that can integrally manage R & D projects from a company-wide point of view in order for researchers to work efficiently and concentrate on the original research. Korean government has increased the investment for the national R&D, and therefore the size of R&D projects has become more larger. Therefore, this study attempts to present a standardized management process and system establishment direction for the efficient management of research and development project and to study the success factor of system establishment for the successful execution of project and the project management plan by the case study.

• Korean Journal of Heritage: History & Science
• /
• v.56 no.2
• /
• pp.222-243
• /
• 2023

In this study, we looked at how to preserve and use the Yibugok earthen fortification ruin in Sangju, which has recently been actively investigated and researched. Now that the coronavirus pandemic has become a reality, a utilization plan using local historical and cultural resources can be the starting point for regional revitalization. To this end, this study first reviewed the historical value of the Sangju Yibugok earthen fortification. The historical and cultural resource value of the fortification was reviewed in recent archaeological achievements along with the results of existing literature research, and distortion in its utilization was avoided. Next, an analysis of the perception of the demand class and local residents, the subject of utilization, was conducted with visitor statistics and surveys. This is because empathy for historical and cultural resources by the demand class and local residents, who are the main agents of utilization, is the most important factor in the use of cultural assets. Based on the theoretical review presented above, the use cases of ancient fortification ruins were examined in the last chapter 4, and a utilization plan for the fortification was presented focusing on empathy. This study was conducted with a focus on the historical value of the use of the fortification ruins, the empathy of the demand class, and the public. In order to overcome the crisis in Sangju, a high-risk area due to population decline, various measures must be proposed, and establishing historical and cultural identity at the center of Sabeolguk and enhancing its image through various utilization measures can be one of the alternatives.

• Journal of Korea Water Resources Association
• /
• v.55 no.4
• /
• pp.257-266
• /
• 2022

Inundation damage is increasing every year due to localized heavy rain and an increase of rainfall exceeding the design frequency. Accordingly, the importance of hydraulic structures for flood control and defense is also increasing. The hydraulic structures are designed according to its purpose and performance, and the amount of flood is an important calculation factor. However, in Korea, design rainfall is used as input data for hydrological analysis for the design of hydraulic structures due to the lack of sufficient data and the lack of reliability of observation data. Accurate probability rainfall and its temporal distribution are important factors to estimate the design rainfall. In practice, the regression equation of temporal distribution for the design rainfall is calculated using the cumulative rainfall percentage of Huff's quartile method. In addition, the 6^th order polynomial regression equation which shows high overall accuracy, is uniformly used. In this study, the optimized regression equation of temporal distribution is derived using the variable selection method according to the principle of parsimony in statistical modeling. The derived regression equation of temporal distribution is verified through the significance test. As a result of this study, it is most appropriate to derive the regression equation of temporal distribution using the stepwise selection method, which has the advantages of both forward selection and backward elimination.

• 한국노년학
• /
• v.32 no.2
• /
• pp.649-668
• /
• 2012

The purpose of this study ahead of the aging society in Korea to prevent problems of the elderly aged new addiction Internet Addiction and identify factors affecting the quantitative increase and qualitative improvement beyond that aims to promote. To this end, residents in Seoul over the age of 60's targets, local welfare, cultural centers, senior centers and other research in the area through one-on-one interviews were conducted the survey. Findings The average degree of Internet addiction elderly 36.16 points (SD = 10.02) and the distribution of at least 20 points to 65 points, respectively. Factors affecting the degree of Internet addiction as a computer time (β = .248, p <.001), mon allowance (β = .180, p <.01), age (β = .139, p <.01) and social support (β = .087, p <.05), self-efficacy (β = - .078, p <.05), most used location (β = - .116, p <.05), degree of family relationship (β = - .147, p <.01), housing type (β = - .153, p <.01), were of the order, this factor was 17.6% of the variance. In other words, the more computer time, the higher the age, the more mon allowance, housing is not self, the lower the degree of family relationship, the house is not a place most used, lower self-efficacy, social support is high As increasing the degree of Internet addiction was thought to be the two predictor variables. Survey results to target the elderly through the Internet addiction group psychotherapy program implementation, and production and distribution of manuals related to Internet use and addiction-related factors, according to the case-by-case Case management services are tailored to be done, and the Internet in general for seniors potential risks related to use in training and preventive services for the elderly will need to be made.

• Economic Analysis
• /
• v.25 no.1
• /
• pp.66-122
• /
• 2019

As the Korean economy grew, employment expanded steadily, with the number of economically active people increasing and the employment-to-population rate also increasing. However, the working age population started to decline in 2017, and the employment of women and young people has been sluggish. The proportion of non-salaried workers in Korea is much higher than in other OECD countries, and is also excessive, considering Korea's income levels. In addition, the proportion of non-regular workers and the proportion of workers employed at small companies are particularly high among salaried workers. In light of these characteristics of Korean employment, the urgent problems facing the employment structure can be summarized by the deepening dual structure of the labor market, the increase in youth unemployment, sluggish female employment figures, and an excessive share of self-employment. Overall, it is seen that labor market duality is the main structural factor of the employment problems in Korea. Therefore, in order to fundamentally address this employment problem, it is necessary to concentrate policy efforts on alleviating labor market duality.

• Journal of Internet of Things and Convergence
• /
• v.10 no.1
• /
• pp.39-45
• /
• 2024

Container volume is a very important factor in accurate evaluation of port performance, and accurate prediction of effective port development and operation strategies is essential. However, it is difficult to improve the accuracy of container volume prediction due to rapid changes in the marine industry. To solve this problem, it is necessary to analyze the impact on port performance using the Internet of Things (IoT) and apply it to improve the competitiveness and efficiency of Busan Port. Therefore, this study aims to develop a prediction model for predicting the future container volume of Busan Port, and through this, focuses on improving port productivity and making improved decision-making by port management agencies. In order to predict port container volume, this study introduced the Extreme Gradient Boosting (XGBoost) technique of a machine learning model. XGBoost stands out of its higher accuracy, faster learning and prediction than other algorithms, preventing overfitting, along with providing Feature Importance. Especially, XGBoost can be used directly for regression predictive modelling, which helps improve the accuracy of the volume prediction model presented in previous studies. Through this, this study can accurately and reliably predict container volume by the proposed method with a 4.3% MAPE (Mean absolute percentage error) value, highlighting its high forecasting accuracy. It is believed that the accuracy of Busan container volume can be increased through the methodology presented in this study.

• Journal of Korea Port Economic Association
• /
• v.40 no.2
• /
• pp.191-204
• /
• 2024

In this study, AHP-based production management job training was developed for MPE companies in the aviation logistics industry. The AHP model was designed with upper and lower classes. Purchase management competency, material management competency, process management competency, and SCM competency were selected as factors of the upper class of production management job training. Lower class evaluation factors were selected for each upper class. As a result of AHP analysis, the relative importance of the upper class evaluation factors was found in the order of SCM competency (0.322), process management competency (0.314), material management competency (0.201), and purchase management competency (0.163). Among the upper classes, it was analyzed that the importance of SCM competency and process management competency was high. The final priority of evaluation factors for the development of the production management curriculum of MPE companies in the aviation logistics industry was analyzed as follows. First, supply chain performance management, which is the lower layer of SCM competency, was analyzed as the top priority factor, and the priorities of evaluation factors were derived such as facility preservation management, which is the lower layer of SCM competency, supply chain production operation, which is the lower layer of SCM competency, process quality management, which is the lower layer of SCM competency, supply chain transportation management, and supply chain supply plan, which are the lower layers of SCM competency

• Journal of the korean academy of Pediatric Dentistry
• /
• v.34 no.2
• /
• pp.273-284
• /
• 2007

The aim of this study was to evaluate the resistance to degradation and to compare the wear resistance characteristics of four esthetic restorative materials in an alkaline solution(0.1N NaOH). The composite resins studied were Composan LCM flow(Promedica, Germany). Clearfil ST(Kuraray medical, Japan), Durafi VS1(Heraeus Kulzer, U.S.A), Point 4(Kerr, U.S.A). The results were as follows : 1. The mass loss of each brand was $1.02{\sim}6.04%$ and highest value in Durafil VS$(6.04{\pm}0.29%)$. 2. The sequence of the degree of degradation layer depth was in descending order by Durafil VS, Clearfil ST, Point 4 and Composan LCM flow. There were significant differences between Point 4, Composan LCM flow and the others (p<0.001). 3. The sequence of the Si loss was in descending order by Clearfil ST, Durafil VS, Composan LCM flow and Point 4. There were significant differences among the materials (p<0.001). 4. On SEM, destruction of bonding between matrix and filler and on CLSM, the depth of degradation layer of specimen surface was observed. 5. The sequence of maximum wear depth was in descending order by Durafil VS, Composan LCM flow, Point 4 and Clearfil ST. There were no significant differences among the materials (p>0.001) 6. The correlation coefficient between Si loss and degradation layer depth (r=0.892, p<0.01) and Si loss and mass loss(r=0.736, p<0.01) were relatively high. These results indicate that hydrolytic degradation, wear and another factor may consider as evaluation factors of composite resins.