• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.7
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• pp.485-496
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• 2019

The current study examined the latent mean analysis and path analysis comparison between male and female groups in the structural relationships among parent-child conversation, peer attachment, satisfaction in teacher at a community child care center, ego-resiliency, self-esteem, and career identity in adolescents who attend a community child care center. For this purpose, 438 adolescents who participated in the 4th(2017) questionnaire in the 2nd child panel of the community child care center were used. From the analysis results, first, peer attachment and satisfaction in teacher at a community child care center increased ego-resiliency and career identity, but parent-child conversation did not predict ego-resiliency and career identity. Peer attachment and satisfaction in teacher at a community child care center was fully mediated by ego-resiliency and self-esteem to career identity. Second, in the latent mean analysis, male students showed significantly higher latent mean values in ego-resiliency and self-esteem than female students, while female students showed significantly higher latent mean values in parent-child conversation than male students. Third, multi-group analysis revealed different paths to career identity between the genders. Peer attachment can buffer the effect of ego-resiliency and self-esteem on career identity of male students, but satisfaction in teacher at a community child care center buffers more on the ego-resiliency of female students. The results of this study suggest that social support for enhancing ego-resiliency and self-esteem is needed to encourage career identity, and that gender needs to be considered.

• Korean Chemical Engineering Research
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• v.59 no.4
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• pp.542-547
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• 2021

Glass lined impellers are corrosion resistant to most chemicals, including strong acids, and also have a smooth, non-stick surface, easy to clean and free from impurities in the process. Glass lined home base impeller is a multi-purpose impeller designed to stir a wide viscosity range of liquids from low viscosity fluids to high viscosity fluids, among others, cell culture, yeast culture, and beer fermentation pots, especially used for air-water system breathable stirring. The glass lining for HB impellers, which are simple in structure and competitive in performance, is essential to have upper and lower division in order to make the joint area between the impeller and shaft as small as possible. The upper and lower division of the impeller hardly affects the mixing performance, but the aeration performance. In this study, in order to optimize the shape of the Glass Lining HB impeller, a study was conducted on the effect of the angle between the upper and lower impellers, the clearance between the impellers, and the number of baffles on the aeration power. The optimal shape and baffle plate conditions for the Glass lined HB impeller were derived through the study results that the angle and the clearance between the upper and lower impellers decreased the ration of the power consumption with aeration P_g and that without aeration P₀, P_g/P₀.

• Convergence Security Journal
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• v.21 no.1
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• pp.201-208
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• 2021

The purpose of this study is to investigate reunification perception among groups with different cognitive bias(anchoring bias) through empirical studies. This study assumes that cognitive bias occurs according to the content of N. Korea provided in school education, and that the cognitive bias formed in youth creates a difference in perception of N. Korea and reunification. For empirical study, a survey of reunification awareness conducted by the Institute for Peace an Unification Studies-Seoul National University was used, and the two groups are divided into A-group that chose "anti-communism or security" and B-group that did "reunification interests, multi-culturalism and understanding North Korea" according to N. Korea content which was encountered in school education during adolescence. A-group recognized N. Korea as a hostile target even after becoming an adult, while B-group regarded N. Korea as a one of dialogue and cooperation. This analysis illustrates the existence of cognitive bias between the two groups because of N. Korea content which was given in school education. A-group had a lower percentage than B-group in terms of the benefits of reunification to S. Korea and the need for more dialogue and compromise with N. Korea. However, there was no difference between two groups in terms of acceptance of N. Korean defectors. This research result could be a reference to the direction of school education policies relating to reunification in that early school education affects reunification awareness and perception related with N. Korea even in adulthood.

• Tunnel and Underground Space
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• v.31 no.3
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• pp.167-183
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• 2021

It is essential to understand the complex thermo-hydro-mechanical-chemical (THMC) coupled behavior in the engineered barrier system and natural barrier system to secure the high-level radioactive waste repository's long-term safety. The heat from the high-level radioactive waste induces thermal pressurization and vaporization of groundwater in the repository system. Groundwater inflow affects the saturation variation in the engineered barrier system, and the saturation change influences the heat transfer and multi-phase flow characteristics in the buffer. Due to the complexity of the coupled behavior, a numerical simulation is a valuable tool to predict and evaluate the THMC interaction effect on the disposal system and safety assessment. To enhance the knowledge of THMC coupled interaction and validate modeling techniques in geological systems. DECOVALEX, an international cooperation project, was initiated in 1992, and KAERI has participated in the projects since 2008 in Korea. In this study, we introduced the main contents of all tasks in the DECOVALEX-2023, the current DECOVALEX phase, to the rock mechanics and geotechnical researchers in Korea.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.22 no.5
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• pp.1-12
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• 2019

It is important to measure the height of trees as an essential element for assessing the forest health in urban areas. Therefore, an automated method that can measure the height of individual tree as a three-dimensional forest information is needed in an extensive and dense forest. Since airborne LiDAR dataset is easy to analyze the tree height(z-coordinate) of forests, studies on individual tree height measurement could be performed as an assessment forest health. Especially in urban forests, that adversely affected by habitat fragmentation and isolation. So this study was analyzed to measure the height of individual trees for assessing the urban forests health, Furthermore to identify environmental factors that affect forest growth. The survey was conducted in the Mt. Bongseo located in Seobuk-gu. Cheonan-si(Middle Chungcheong Province). We segment the individual trees on coniferous by automatic method using the airborne LiDAR dataset of the two periods (year of 2016 and 2017) and to find out individual tree growth. Segmentation of individual trees was performed by using the watershed algorithm and the local maximum, and the tree growth was determined by the difference of the tree height according to the two periods. After we clarify the relationship between the environmental factors affecting the tree growth. The tree growth of Mt. Bongseo was about 20cm for a year, and it was analyzed to be lower than 23.9cm/year of the growth of the dominant species, Pinus rigida. This may have an adverse effect on the growth of isolated urban forests. It also determined different trees growth according to age, diameter and density class in the stock map, effective soil depth and drainage grade in the soil map. There was a statistically significant positive correlation between the distance to the road and the solar radiation as an environmental factor affecting the tree growth. Since there is less correlation, it is necessary to determine other influencing factors affecting tree growth in urban forests besides anthropogenic influences. This study is the first data for the analysis of segmentation and the growth of the individual tree, and it can be used as a scientific data of the urban forest health assessment and management.

• Journal of the Korean Society of Industry Convergence
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• v.23 no.6_2
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• pp.1067-1074
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• 2020

Green houses provide a more conditioned and warmer environment than the outside environment due to insulation. Currently used insulation materials include soft film (PVC, PE, EVA), foamed PE sheet, non-woven fabric, reflective film, and multi-layer insulation curtain, but there are many disadvantages and to compensate for this, silica aerogel insulation material with excellent warmth, light weight, and small volume Research using is in progress. In this study, the temperature change of the quadruple-structure green house and the temperature change in the dual-structure green house of soft film and silica airgel were investigated. The daytime temperature change was highest in A and A2 (soft film) at 10 to 16:00 after sunrise, but showed the lowest temperature at 17 to 18:00, which is the sunset time, showing the greatest change. The airgels of D and D2 showed the smallest change in temperature after sunrise and right after sunset. That is, it can be said that the airgel is hardly affected by external temperature. The temperature change at night was highest in D and D2 (aerogel) for both quadruple and dual structures. The temperature at night was measured higher in the quadruple structure than in the double structure. As for the ratio of the internal temperature to the external temperature for the quadruple structure and the double structure, D (aerogel) was not affected by the external temperature during the day in the quadruple structure and the double structure. D (Aerogel) seems to be able to reduce the damage caused by high temperatures in summer due to the high thermal insulation effect of the airgel, as the temperature rises above 4℃ at night. And in winter, it helps to save heating costs due to less heat emitted to the outside.

• Korean Journal of Remote Sensing
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• v.37 no.3
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• pp.475-491
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• 2021

With the recent increase in available high-resolution (< ~1 m) satellite SAR images, the demand for precise registration of SAR images is increasing in various fields including change detection. The registration between high-resolution SAR images acquired in different look angle is difficult due to speckle noise and geometric distortion caused by the characteristics of SAR images. In this study, registration is performed in two stages, coarse and fine, using the x-band SAR data imaged at staring spotlight mode of TerraSAR-X. For the coarse registration, a method combining the adaptive sampling method and SAR-SIFT (Scale Invariant Feature Transform) is applied, and three rigid methods (NCC: Normalized Cross Correlation, Phase Congruency-NCC, MI: Mutual Information) and one non-rigid (Gefolki: Geoscience extended Flow Optical Flow Lucas-Kanade Iterative), for the fine registration stage, was performed for performance comparison. The results were compared by using RMSE (Root Mean Square Error) and FSIM (Feature Similarity) index, and all rigid models showed poor results in all image combinations. It is confirmed that the rigid models have a large registration error in the rugged terrain area. As a result of applying the Gefolki algorithm, it was confirmed that the RMSE of Gefolki showed the best result as a 1~3 pixels, and the FSIM index also obtained a higher value than 0.02~0.03 compared to other rigid methods. It was confirmed that the mis-registration due to terrain effect could be sufficiently reduced by the Gefolki algorithm.

• Korean Journal of Remote Sensing
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• v.37 no.3
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• pp.577-589
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• 2021

Drone mapping systems can be applied to many fields such as disaster damage investigation, environmental monitoring, and construction process monitoring. To integrate individual sensors attached to a drone, it was essential to undergo complicated procedures including time synchronization. Recently, a variety of composite sensors are released which consist of visual sensors and GPS/INS. Composite sensors integrate multi-sensory data internally, and they provide geotagged image files to users. Therefore, to use composite sensors in drone mapping systems, mapping accuracies from composite sensors should be examined. In this study, we analyzed the mapping accuracies of a composite sensor, focusing on the data acquisition area and pre-calibration effect. In the first experiment, we analyzed how mapping accuracy varies with the number of ground control points. When 2 GCPs were used for mapping, the total RMSE has been reduced by 40 cm from more than 1 m to about 60 cm. In the second experiment, we assessed mapping accuracies based on whether pre-calibration is conducted or not. Using a few ground control points showed the pre-calibration does not affect mapping accuracies. The formation of weak geometry of the image sequences has resulted that pre-calibration can be essential to decrease possible mapping errors. In the absence of ground control points, pre-calibration also can improve mapping errors. Based on this study, we expect future drone mapping systems using composite sensors will contribute to streamlining a survey and calibration process depending on the data acquisition circumstances.

• 한국사회정책
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• v.24 no.2
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• pp.61-86
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• 2017

Along with the well-established evidence on the negative effect of social isolation on physical and mental health, increasing attention has been paid to multi-dimensional nature of social isolation. One line of study on social isolation has discussed different pathways between objective and subjective social isolation and health. Another stream of the research focused on the possibly non-linear association between social isolation and health by age cohort groups. Drawing from the two lines of research, this study aimed at empirically examine to what extent objective and subjective social isolation are associated with physical and mental health independently and how the associations vary by three age cohorts(i.e. the middle-aged, the young old, the old-old). Data came from the first wave of Korean Social Life, Health and Aging Project (KSHAP) (N= 814). Findings showed 1) objective subjective isolation were significantly related with worse physical and mental health, interestingly, subjective social isolation was associated with mental health only, 2) pattern of association between social isolation and physical health varied by age cohorts. Specifically, compared to the middle-aged, the young old with higher objective social isolation exhibited lower level of physical health, while the old-old with higher subjective social isolation were likely to experience lower physical health. Based on the findings, we discussed implications and suggestions for future research and relevant policy/program development for ameliorating objective and subjective social isolation.

• Journal of Family Relations
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• v.21 no.1
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• pp.143-160
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• 2016

Objectives: The purpose of this study is to empirically verify the difference between traditional gender role attitude and realistic dual earner attitude. Most preceding studies analyzed gender role attitude by summated rating scale while few studies have been conducted on the difference between traditional gender role attitude and dual earner attitude. Method: By using the 9th Korea Welfare Panel Data (year 2014), this study extracted households of married couples and with children in working age (18 through 64 years of age) who are the main subjects in work-family relationship. First, this study classified traditional group and modern group in their gender role attitude and passive group and active group in their dual earner attitude and by crossing these attitudes, drew out 4 gender role/dual earner attitudes. For analysis, this study investigated frequency of attitude types through descriptive statistics. By conducting ANOVA, study verified if there are significant differences in the satisfaction with family relationship depending on the types of gender role/dual earner attitudes. Lastly, study examined the effect of socio-economic status and demographic characteristics on the types of gender role/dual earner attitudes by conducting multi-nominal logistic regression analysis. Results: As the result of analysis, first, half of respondents belonged to 'equal-role-oriented type' who has modern gender role attitude and active dual earner attitude. However, there were not a few 'dual-earner-avoiding type' who has modern gender role attitude but passive dual earner attitude and 'incongruous attitude type' who has traditional gender role attitude but active dual earner attitude. Next, 'incongruous attitude type' had significantly low level of satisfaction with overall family life, relationship with spouse and relationship with children than other attitude types. Lastly, those whose incomes belong to poor strata, those who are high school graduates and lower, males and those who are over the age of 60 had significantly higher probability of belonging to 'incongruous attitude type.' Conclusion: The results of analysis demonstrate that the difference between gender role attitude and dual earner attitude is an important matter and since 'incongruous attitude type' exhibits low level of satisfaction with family relationship, scrupulous policy approaches are required for those who have high possibility of belonging to 'incongruous attitude type.'