• Journal of Space Technology and Applications
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• v.1 no.1
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• pp.23-32
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• 2021

The high-level Space Situational Awareness (SSA) objective is to provide to the users dependable, accurate and timely information in order to support risk management on orbit and during re-entry and support safe and secure operation of space assets and related services. Therefore the risk assessment for the re-entry of space objects should be managed nationally. In this research, the Software for Re-Entry Prediction of space objects (SREP) was developed for national SSA system. In particular, the rate of change of the drag coefficient is estimated through a newly proposed Drag Scale Factor Estimation (DSFE), and is used for high-precision orbit propagator (HPOP) up to an altitude of 100 km to predict the re-entry time and position of the space object. The effectiveness of this re-entry prediction is shown through the re-entry time window and ground track of space objects falling in real events, Grace-1, Grace-2, Tiangong-1, and Chang Zheng-5B Rocket body. As a result, through analysis 12 hours before the final re-entry time, it is shown that the re-entry time window and crash time can be accurately predicted with an error of less than 20 minutes.

• Journal of The Korean Society of Integrative Medicine
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• v.10 no.4
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• pp.229-240
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• 2022

Purpose : In this study, using Oyster Shell Thermal Therapy for metabolic diseases, we analyzed the effect of immune and inflammation-related variables and respiratory health-related variables of test subjects to verify the effect of improving respiratory health. Methods : In this study, 26 patients with metabolic diseases were divided into an experimental group (N=13) and a control group (N=13). After Oyster Shell Thermal Therapy (four weeks/three times a week/1 hour per time), metabolic disease-related variables and immune and respiratory health-related variables were measured and compared between the two groups. The conclusion of this study is as follows: Results : After the four-week Oyster Shell Thermal Therapy, in terms of changes in the metabolic disease-related variables, the control group exhibited a higher increase in TC and LDL-C levels than the experimental group. In the case of glucose, the experimental group showed a decrease after the experiment (p<.05). After the four-week thermotherapy, a statistically significant interactive effect occurred in natural killer (NK) cells among the immune-related variables. According to the results of a post-experimental analysis, the control group showed a higher decrease in NK cells than the experimental group (p<.05). After the 4-weeks thermotherapy, the experimental group showed a greater increase in maximum oxygen intake of the respiratory health-related variables than the control group. Conclusion : Based on a comprehensive review of the study results, the subjects who underwent the four-week Oyster Shell Thermal Therapy exhibited positive physical changes in metabolic disease-related variables as well as immune and respiratory health-related variables, which demonstrates the effectiveness of Oyster Shell Thermal Therapy on immune and respiratory health. Accordingly, it is recommended to conduct long-term Oyster Shell Thermal Therapy with various models in terms of the size and shape.

• Journal of the Korea Institute of Building Construction
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• v.22 no.4
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• pp.391-402
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• 2022

With the number of social overhead capital(SOC) projects that introduce private capital on the rise, overseas construction global companies today need to establish and advance their overseas order strategies. In this context, the purpose of this study is to develop the public private partnership(PPP) capacity evaluation model for developing countries and use it for domestic overseas construction companies to establish strategies for overseas expansion. The PPP competency evaluation model analyzes the importance of PPP competency evaluation items and infrastructure environment competency evaluation items through a review of previous studies and an interview survey with overseas construction experts. Through the above analysis results and expert surveys, problems that may occur when overseas construction companies enter the PPP market were derived, and improvement measures were proposed. Countries with a high probability of overseas construction companies entering the PPP market were determined to be those that have a mature PPP system, low risk in construction, and a good entry environment with a high infrastructure market size and growth rate. In addition, a lack of PPP investment experience, the absence of information on the infrastructure environment, and a shortage of PPP experts were identified as problems when entering the overseas construction PPP market. As an improvement measure, it was suggested to enter in cooperation with domestic and foreign companies. In addition, a plan was proposed to develop a curriculum to secure experts in areas such as PPP finance and contracts and to provide PPP information for each country. These findings are expected to contribute to overseas construction companies proposing strategies for entering the overseas construction market and using them for overseas expansion strategies and policy establishment.

• Information Systems Review
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• v.25 no.4
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• pp.27-45
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• 2023

The importance of information security has grown alongside the development of information and communication technology. However, companies struggle to select suitable countermeasures within their limited budgets. Sönmez and Kılıç (2021) proposed a model using AHP and mixed integer programming to determine the optimal investment combination for mitigating information security breaches. However, their model had limitations: 1) a lack of objective measurement for countermeasure efficacy against security threats, 2) unrealistic scenarios where risk reduction surpassed pre-investment levels, and 3) cost duplication when using a single countermeasure for multiple threats. This paper enhances the model by objectively quantifying countermeasure efficacy using the beta probability distribution. It also resolves unrealistic scenarios and the issue of duplicating investments for a single countermeasure. An empirical analysis was conducted on domestic SMEs to determine investment budgets and risk levels. The improved model outperformed Sönmez and Kılıç's (2021) optimization model. By employing the proposed effectiveness measurement approach, difficulty to evaluate countermeasures can be quantified. Utilizing the improved optimization model allows for deriving an optimal investment portfolio for each countermeasure within a fixed budget, considering information security costs, quantities, and effectiveness. This aids in securing the information security budget and effectively addressing information security threats.

• Journal of Korean Home Economics Education Association
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• v.35 no.4
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• pp.33-45
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• 2023

The purpose of this study is to investigate the association between dietary behavior and related factors according to the generalized anxiety disorder (GAD) in adolescents. The results of analyzing demographic characteristics according to the GAD showed that gender, age, BMI, type of school, residence type, father's nationality, smoking and drinking experience, perceived health status, perception of body shape, economic status, academic achievement, physical activity, sedentary time and smartphone usage time were related to the GAD (p<0.01). The results of analyzing dietary behavior according to the GAD showed that the frequency of water intake, sweetened beverage intake, fast food intake, fruit intake and breakfast intake were related to the GAD (p<0.001). The results of analyzing depression and suicidality according to the GAD showed that depression, suicidal ideation, planning, and attempts were all related to the GAD (p<0.001). Even after adjusting for factors corresponding to demographic characteristics, it was confirmed that the level of GAD had a significant effect on depression and suicidality. This study is significant in that it provided basic data on adolescent mental health problems by analyzing dietary behavior and related factors according to the level of GAD.

• Journal of Preventive Medicine and Public Health
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• v.40 no.5
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• pp.363-370
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• 2007

Objectives: The principal objective of this study was to determine the relationship between maternal exposure to air pollution and low birth weight and to propose a possible environmental health surveillance system for low birth weight. Methods: We acquired air monitoring data for Seoul from the Ministry of Environment, the meteorological data from the Korean Meteorological Administration, the exposure assessments from the National Institute of Environmental Research, and the birth data from the Korean National Statistical Office between January 1, 2002 and December 31, 2003. The final birth data were limited to singletons within $37{\sim}44$ weeks of gestational age. We defined the Low Birth Weight (LBW) group as infants with birth weights of less than 2500g and calculated the annual LBW rate by district. The air monitoring data were measured for $CO,\;SO_2,\;NO_2,\;and\;PM_{10}$ concentrations at 27 monitoring stations in Seoul. We utilized two models to evaluate the effects of air pollution on low birth weight: the first was the relationship between the annual concentration of air pollution and low birth weight (LBW) by individual and district, and the second involved a GIS exposure model constructed by Arc View 3.1. Results: LBW risk (by Gu, or district) was significantly increased to $1.113(95%\;CI=1.111{\sim}1.116)\;for\;CO,\;1.004(95%\;CI=1.003{\sim}1.005)\;for\;NO_2,\;1.202(95%\;CI=1.199{\sim}1.206\;for\;SO_2,\;and\;1.077(95%\;CI=1.075{\sim}1.078)\;\;for\;PM_{10}$ with each interquartile range change. Personal LBW risk was significantly increased to $1.081(95%\;CI=1.002{\sim}1.166)\;for\;CO,\;1.145(95%\;CI=1.036{\sim}1.267)\;for\;SO_2,\;and\;1.053(95%\;CI=1.002{\sim}1.108)\;for\;PM_{10}$ with each interquartile range change. Personal LBW risk was increased to $1.003(95%\;CI=0.954{\sim}1.055)\;for\;NO_2$, but this was not statistically significant. The air pollution concentrations predicted by GIS positively correlated with the numbers of low birth weights, particularly in highly polluted regions. Conclusions: Environmental health surveillance is a systemic, ongoing collection effort including the analysis of data correlated with environmentally-associated diseases and exposures. In addition. environmental health surveillance allows for a timely dissemination of information to those who require that information in order to take effective action. GIS modeling is crucially important for this purpose, and thus we attempted to develop a GIS-based environmental surveillance system for low birth weight.

• Journal of agriculture & life science
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• v.45 no.6
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• pp.163-173
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• 2011

The objective of this study was to determine microbiological risk factors in hot pepper farms for the application of good agricultural practices (GAP). Samples were collected from cultivation environments and utensils, plants, workers, and air at 3 hot pepper farms located in Cheongsong, Korea and were tested to detect sanitary indications [aerobic plate bacteria (APC), coliform, and Escherichia coli], foodborne pathogens, and fungi. APC, coliform, and fungi were detected at the levels of 0.7~6.2, 0.2~4.7, and 0.4~4.3 log CFU, respectively, in the three farms. Four (4.4%; l leaf, l irrigation water, and 2 soil) of 90 samples collected were revealed to be E. coli positives. For foodborne pathogens, Staphylococcus aureus was only detected at $1.0log\;CFU/100cm^2$ in the worker's cloth of B farm, and Bacillus cereus was detected at the levels 1.0~2.5 log CFU in the cultivation environments and utensils and worker of B and C farms. However, other pathogens were not detected. The results demonstrated potential microbiological risks for hot pepper cultivated in the farms. Therefore, a management system to minimize the microbial risk such as GAP is required to ensure the safety of hot pepper.

• Korean Journal of Remote Sensing
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• v.37 no.6_2
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• pp.1819-1827
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• 2021

Land-use/cover change caused by rapid urbanization in South Korea is one of the concerns in flood risk management because groundwater recharge by precipitation hardly occurs due to an increase in impermeable surfaces in urban areas. This study investigated the hydrologic effects of land-use/cover on groundwater recharge in the Yeonje-gu district of Busan, South Korea. A statistical time series analysis was conducted with temporal variations of precipitation and groundwater level to estimate lag-time based on correlation coefficients calculated from auto-correlation function (ACF), cross-correlation function (CCF), and moving average (MA) at five sites. Landform and land-use/cover within 250 m radius of the monitoring wells(GW01, GW02, GW03, GW04, and GW05) at five sites were identified by land cover and digital map using Arc-GIS software. Long lag-times (CCF: 42-71 days and MA: 148-161 days) were calculated at the sites covered by mainly impermeable surfaces(GW01, GW03, and GW05) while short lag-times(CCF: 4 days and MA: 67 days) were calculated at GW04 consisting of mainly permeable surfaces. The results suggest that lag-time would be one of the good indicators to evaluate the effects of land-use/cover on estimating groundwater recharge. The results of this study also provide guidance on the application of statistical time series analysis to environmentally important issues on creating an urban green space for natural groundwater recharge from precipitation in the city and developing a management plan for hydrological disaster prevention.

• The Journal of the Convergence on Culture Technology
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• v.7 no.1
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• pp.397-405
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• 2021

With the recent phenomenon of the Intelligence Information Society, the cyber security paradigm has begun to change. In particular, the increase of the interconnectedness of the hyperlinked society has extended the scope of damage that can be caused by cyber threats to the real world. In addition to that, it can also be a risk to any given individual who could accompany a crisis that has to do with public safety or national security. Adolescents who are digital natives are more likely to be exposed to cyber threats, which is mainly due to the fact that they are significantly more involved in cyber activities and they also possess insufficient security comprehension and safety awareness. Therefore, it is necessary to strengthen cyber security capabilities of every young individual, so that they can effectively protect themselves against cyber threats and better manage their cyber activities. It examines the changes of the security paradigm and the necessity for cyber security education, which is in direct accordance to the characteristics of a connected society that further suggests directions and a basic system of cyber security education, through a detailed analysis of the current state of Domestic and Overseas Cyber Security Education. The purpose of this study was to define cybersecurity competencies that are necessary within an intelligent information society, and to propose a regular curriculum for strengthening cybersecurity competencies, through the comparison and meticulous analysis of both domestic and overseas educational systems that are pertinent to cybersecurity competencies. Accordingly, a cybersecurity competency system was constructed, by reflecting C3-Matrix, which is a cyber competency system model of digital citizens. The cybersecurity competency system consists of cyber ethics awareness, cyber ethics behavior, cyber security and cyber safety. In addition to this, based on the basic framework of the cybersecurity competency system, the relevant education that is currently being implemented in the United States, Australia, Japan and Korea were all compared and analyzed. From the insight gained through the analysis, the domestic curriculum was finally presented. The main objective of this new unified understanding, was to create a comprehensive and effective cyber security competency curriculum.

• Korean Journal of Social Welfare
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• v.59 no.1
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• pp.301-327
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• 2007

The purpose of this study is to examine the timing and the risk factors associated with the adoption of legally-free foster children. The sample of the study was drawn from foster care files of Adoption and Foster Care Analysis and Reporting System(AFCARS) in 32 states between October 1998 (FY 1999) and September 2002(FY 2002). The timing post-TPR to adoption was examined by plotting the Kaplan-Meier cumulative hazard function for adoption and by plotting the KM hazard functions stratified by child's race and child's age at TPR. Cox proportional-hazards regression analysis was used to identify risk factors for adoption of legally-free foster children after TPR. The hazard of adoption was very low immediately after TPR but increased steadily starting at 3 months and then declined after 20 months. The cumulative hazard functions for White non-Hispanic children and Black non-Hispanic children crossed over at 13 months after TPR. Racial minority status, older age, and disability were negatively associated with the hazard of adoption. Physical abuse, sexual abuse had the lower hazard for adoption compared by neglect. Caretaker's inability to cope had the slightly lower hazard for adoption whereas inadequate housing showed the slightly greater hazard for adoption. Characteristics of foster care services turned into be powerful predictors of adoption. Specifically, legally-free children placed in pre-adoptive homes, those who shared the same racial/ethnic background with their foster caretakers, and those who were placed in two-parent families have a greater likelihood of adoption. The findings highlight the importance of foster care service provisions after TPR to facilitate adoption of legally-free foster children. Furthermore, a more substantial resources and targeted support for foster children who experience physical abuse and sexual abuse in need of adoption should be provided for moving the foster children into permanency.