• Journal of the Korean Association of Geographic Information Studies
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• v.22 no.3
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• pp.99-106
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• 2019

Technology that cannot be excluded from 4th industry is self-driving sector. The self-driving sector can be seen as a key set of technologies in the fourth industry, especially in the DB sector is getting more and more popular as a business. The DB, which was previously produced and managed in two dimensions, is now evolving into three dimensions. Among the data obtained by Mobile Mapping System () to produce the HD MAP necessary for self-driving, Point Cloud, which is LiDAR data, is used as a DB because it contains accurate location information. However, at present, it is not widely used as a base data for 3D modeling in addition to HD MAP production. In this study, MMS Point Cloud was used to extract facilities around the road and to overlay the location to expand the usability of Point Cloud. Building utility poles and communication poles DB from Point Cloud and comparing road name address base and location, it is believed that the accuracy of the location of the facility DB extracted from Point Cloud is also higher than the basic road name address of the road, It is necessary to study the expansion of the facility field sufficiently.

• Korean Journal of Construction Engineering and Management
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• v.20 no.1
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• pp.22-31
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• 2019

The application of BIM that can manage and integrate information generated during the entire life cycle of buildings in domestic and overseas construction projects is becoming active. When BIM is utilized in the construction phase, it can shorten the construction period, reduce the occurrence of reworks and improve collaboration capability. However, there are limitations in applying BIM to the construction phase due to the insufficient definition level of domestic BIM guidelines and inadequate design standards. In this regard, this study developed BIM model requirements checklist for the application of BIM in the construction phase. To develop the checklists, 21 domestic and overseas BIM guidelines, three public construction projects and four private construction projects to which construction BIM was applied, were analyzed. Based on the guidelines and cases, a total of 62 construction BIM model requirements (31 model objects and 31 attribute rules) and proposed construction BIM model requirement checklists by dividing the 61 requirements according to the requirement and purpose for utilization were identified. It is expected that the practical applications of the checklists proposed in this study will improve the level of BIM model in construction phase. In addition, this study has its significance as a basic research that can be used in the development of standardized guidelines for BIM model in construction phase from academic aspects.

• Journal of Korean Society of Forest Science
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• v.108 no.3
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• pp.364-371
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• 2019

This study was conducted to provide the basic information for a reasonable forest management plan and sustainable forest management by developing a dominant tree height growth model using diameter at breast height (DBH) and site index curves for Pinus densiflora and Chamaecyparis obtusa growing in Jeolla-do. The altitude, slope, orientation, soil type, height and DBH of a dominant tree, and the ages of trees were measured for 3055 Pinus densiflora trees (611 plots) and 3345 Chamaecyparis obtusa trees (699 plots), and these data were used to develop a customized afforestation map. In the dominant tree height growth model, the relationship to DBH was used in the Petterson, Michailow, and log equations. Also, a dominant tree height growth model in relationship to age used the Chapman-Richards, Schumacher, and Gompertz equations. The Petterson equation, which has a lower mean square error, was used to model dominant tree height growth in relationship to DBH. In the model of dominant tree height growth in relationship to age, three kinds of equations were considered to have little statistical difference. Therefore, the Chapman-Richards equation was chosen for modeling on the national level. Thirtyyears was used as the base age, which is an important factor for estimating the site index curves. In the results, a more varied range of site index family curves with 6-18 was developed for Pinus densiflora, and with 6-22 for Chamaecyparis obtusa. As the new site index curves indicated influences on growth of Pinus densiflora and Chamaecyparis obtusa, a reasonable forest management plan will be possible in the future for Jeolla-do.

• Korean Chemical Engineering Research
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• v.57 no.5
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• pp.706-713
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• 2019

In this study, basic research was conducted to provide guidelines for selecting printers and materials suitable for each application case by analyzing 3D printing method and surface characteristics of materials suitable for microfluidic system. We have studied the surface characteristics according to the materials for the two typical printing methods: The most commonly used method of Fused Deposition Modeling (FDM) printing and the relatively high resolution method of Stereolithography (SLA) printing. The FDM prints exhibited hydrophilic properties before post - treatment, regardless of the material, but showed hydrophobic properties after post - treatment with acetone vapor. It was confirmed by the observation of surface roughness using SEM that the change of the contact angle was due to the removal of the surface structure by post-treatment. SLA prints exhibited hydrophilic properties compared to FDM prints, but they were experimentally confirmed to be capable of surface modification using hydrophobic coatings. It was confirmed that it is impossible to make a transparent specimen in the FDM method. However, sufficient transparency is secured in the case of the SLA method. It is also confirmed that the electroporation chip of the digital electroporation system based on the droplet contact charging phenomenon was fabricated by the SLA method and the direct application to the microfluidic system by demonstrating the electroporation successfully.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.7
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• pp.440-447
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• 2019

The purpose of this study was to identify the relationship between leisure function, self-esteem and social role loss among golf players in the middle age. Furthermore, it was meaningful to provide basic data on leisure activities and healthy retirement preparation through golf at the present time of the aging society. The subjects of study who adults were recruited from Seoul, Gyeonggi-do. For the data processing, it conducted frequency, reliability, confirmatory factor, correlation, and structure equaling modeling analyses. The results were as follows; First, leisure function of middle age golf participant had a positive influence on self-esteem(p<.05). Second, leisure function of middle age golf participant had a positive influence on social role loss(p<.05). Third, self-esteem of middle age golf participant had a positive influence on social role loss(p<.05). Forth, self-esteem mediated the relationship between middle age golf participant leisure function and social role loss.(p<.05).

• Smart Media Journal
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• v.9 no.4
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• pp.152-161
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• 2020

In the construction, VR(Virtual Reality) is simply used by users to implement and experience 3D modeling in virtual reality, such as safety, practical education, and promotion. The VR related research includes content development and visualization simulation such as disaster safety evacuation simulation and design education contents. Research on developing suitable VR and presenting directionality is insufficient, which is required in practice. Therefore, in this study, prior to the development of VR suitable for the construction, quantitative evaluation, and analysis based on the judgment of experts are performed. However, the research was conducted on the design stages, which are believed to have high needs and application effects of VR during the lifecycle of construction. There are nine tasks that can be applied to VR in the design stage, and these tasks were evaluated and analyzed using IPA(Importance Performance Analysis) by surveying the level of expectations, importance, and performance. As a result, it was evaluated and analyzed that VR and content development was necessary for the review of member interference and collaboration work for decision making among related stakeholders. The results of this study are expected to be used as basic data for the development of VR to be applied in the design stage to the future.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.12
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• pp.346-353
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• 2020

The purpose of this study was to explore types of longitudinal changes in interactions between mothers and 4-year-old children in primary school as well as the effects on media device addiction. To explore interaction types between mothers and children, latent class growth modeling (LCGM) and BCH were used in a three-step approach. Data from the 6-10th wave of the Panel Study of Korea Children were used. First, the trajectory of the mother-child interactions was linear and decreased across time. This linear decrease was classified into the following three trajectories: high-decreasing, average-deceasing, and low-decreasing. Second, BCH was performed to examine media device addiction in each trajectory, and the findings show that children who had low initial mother-child interactions over time were more likely to experience daily disturbances in adaptive functions such as withdraw or tolerance than other groups of children. The results indicate that maximizing the quality of mother-child interactions in childhood through primary school can lower media device addiction in children.

• Journal of the Korean Society of Radiology
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• v.16 no.3
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• pp.233-240
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• 2022

Research on the presence or absence of radiation shielding for FDM-type filaments has recently begun to be studied, but filaments with shielding capabilities are not sold in Korea, and not studies yet. Therefore, in this research, we will use HDPE (High Density Polyethylene) as a base material, select bismuth as a reinforcing material to manufacture a composite filament, evaluate the shielding ability, and provide basic data for the development of a radiation shielding composite material using 3D printing.A filament is produced by mixing Bismuth with an effective atomic number 83 with HDPE of PE series and adjusting the content of Bismuth to 20% wt, 30% wt, 40% wt. Compounded filaments were evaluated for their physical properties and shielding capabilities by ASTM evaluation methods. As the bismuth content increases, the density, weight, and tensile strength increase, and the shielding capacity is confirmed to be excellent. As a result of the radiation shielding capacity evaluation, it was confirmed that HDPE (80%) + Bi (20%) showed a shielding rate of 82% at 60 kV and a shielding rate of up to 94% or more at 40% bismuth content. In this study, we confirmed that it was possible to produce a radiation shield that is lighter than the metal particle-containing filaments. Furthermore, that have been shield radiation by using HDPE + Bi filaments, and radiation in the medical and radiation industries. The possibility of using it as a shielding complex was confirmed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.5
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• pp.71-80
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• 2021

The purpose of this study is to explore the structural relationships among parents' educational involvement and parental efficacy on students' school life satisfaction and school achievement and to determine whether there are any differences depending on family type and school level. Using data from 2,497 families that participated in the 2018 National Survey on Children's Life, t-tests and structural equation modeling were conducted. The results of this study demonstrated that two-parent families reported higher levels of educational involvement than single-parent families and custodial grandparent families. Also, two-parent families raising children in elementary schools showed higher educational involvement than two-parent families raising children attending middle schools. Second, parental efficacy was found to mediate the effects of parents' educational involvement on students' school life satisfaction and school achievement. Third, the path coefficients between parents' educational involvement, students' school life satisfaction, and school achievement showed statistically significant differences depending on family type, with two-parent families having greater involvement than single-parent families and custodial grandparent families. Fourth, multiple group analysis reported a statistically significant difference in the relationship between parents' educational involvement and school achievement as well as parental efficacy and school achievement depending on the school level.

• Journal of the Korean Association of Geographic Information Studies
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• v.25 no.2
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• pp.30-47
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• 2022

This study analyzed the characteristics of cold air flow according to spatial types in urban areas of Changwon-si, Gyeongsangnam-do. The spatial types were classified by cluster analysis considering the land use map, building information, and topographic characteristics produced on the Changwon biotope map. The amount of cold air and wind speed were derived by KLAM_21 modeling. As a result, spatial types were classified into a total of 14 types considering the density and height of buildings, land use types, and topographic characteristics. Cold air flow was found to generate cold air in the valley of the forest area outside urban area, move through roads and open spaces, and accumulate in the low-lying national industrial complex, and then spread cold air throughout the urban areas. There was a lot of cold air flow in the tall building area, and the cold air accumulation was less in the slope and ridge areas. The results of this study were able to understand the characteristics of cold air flow according to building density, land use type, and topography, which will be usefully used as basic data for urban wind road construction to mitigate climate and improve air quality in urban areas.